Anal. Method Environ. Chem. J. 4 (1) (2021) 5-15  
Research Article, Issue 1  
Analytical Methods in Environmental Chemistry Journal  
AMECJ  
Separation and determination of cadmium in water samples  
based on functionalized carbon nanotube by syringe filter  
membrane-micro solid-phase extraction  
Jamshid Rakhtshah a,*  
a Department of Inorganic Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, Iran  
A B S T R A C T  
A R T I C L E I N F O :  
Received 19 Nov 2020  
Revised form 25 Jan 2021  
Accepted 22 Feb 2021  
Asimple and fast separation of cadmium (Cd) based on functionalized  
carbon nanotubes with 2,3-dimercapto-1-propanol (CNTs@DHSP)  
was achieved in water samples before a determination by atom trap  
flame atomic absorption spectrometry (AT-FAAS). In this study,  
Cd(II) ions were extracted by syringe filter membrane-micro solid  
phase extraction procedure(SFM-μ-SPE). Firstly, 20 mg of the  
CNTs@DHSP as solid-phase added to 20 mL of water sample in  
a syringe, then dispersed for 3 min after adjusting pH up to 7 and  
pass through SFM very slowly. After extraction, the Cd(II) ions  
were back-extracted from SFM/CNTs@DHSP by 1.0 mL of eluent  
in acidic pH. Finally, the cadmium concentration was measured by  
AT-FAAS. Under the optimal conditions, the linear range (2–90 µg  
L−1), LOD (0.75 µg L−1) and enrichment factor (19.6) were obtained  
(RSD<1.5%). The adsorption capacity of Cd(II) with the CNTs@  
DHSP was obtained about 152.6 mg g-1. The method was validated  
by certified reference materials (SRM, NIST) and ET-AAS in water  
samples.  
Available online 28 Mar 2021  
------------------------  
Keywords:  
Cadmium,  
Separation,  
Water,  
Functionalized carbon nanotubes,  
Syringe filter membrane micro solid  
phase extraction,  
Atom trap flame atomic absorption  
spectrometry  
gastrointestinal and respiratory tract system  
1. Introduction  
from food, water, air pollution and smoking. The  
cadmium exposure causes to hepatic dysfunction,  
the pulmonary edema, the testicular damage, the  
osteoporosis and cancer in different organs such as,  
breast, renal, lung and pancreas [3,4]. The Cd ions  
absorb through the respiratory tract or the gastro-  
intestinal tract and enters into the bloodstream via  
erythrocytes and accumulated in the kidneys liver [5].  
Cadmium ions excrete from the human body through  
urine. The liver and kidneys are able to synthesize  
metallothioneins (MT) which protect the cells from  
cadmium toxicity through bonding to cadmium  
(Cd- MT) [6]. Mitochondria play a crucial role in  
the formation of ROS (reactive oxygen species) for  
cadmium [7]. Moreover, the different methodologies  
Cadmium (Cd) as a toxic non-essential metal  
release from industrial activity to water, soil, food,  
agricultural product and air, then, cadmium ions  
cause to environmental and human health hazards.  
Cadmium is naturally creating in the environment  
matrixes from agricultural and chemical industrial  
sources. The sources of cadmium have various  
applications in different industry such as PVC  
products in petrochemical industries, pigments  
in color factories, and Ni-Cd batteries [1,2].  
The cadmium enters to the human body through  
*Corresponding Author: Jamshid Rakhtshah  
Anal. Method Environ. Chem. J. 4 (1) (2021) 5-15  
6
such as microbial fermentation based on TiO2  
nanoparticles have been used to remove cadmium  
from waters efficiently [8,9]. The cytotoxic effects of  
cadmium cause to apoptotic effect in human which  
was reported by internationalAgency for research on  
cancer (IARC) [10]. Itai itai disease or osteomalacia  
is chronic cadmium poisoning was reported in Japan.  
The cadmium intake to the human body is about 7 µg  
Cd per week. This value cause to create the cadmium  
concentration in renal and urine between 100-200 µg  
g-1 and less than 0.5 µg g-1 creatinine, respectively.  
Blood and urinary cadmium at 0.38 µg L-1 and  
0.67 µg g-1 creatinine were associated with tubular  
impairment. Urinary cadmium at 0.8 µg g-1 creatinine  
was associated with glomerular impairment [11]. So,  
the extraction and determination of Cd(II) in waters  
is very important, due to the environment and human  
health safety. Recently, various analytical techniques  
can be used for cadmium extraction in different  
water, foods and environmental samples. The  
various methods such as flame atomic absorption  
spectrometry (AAS) [12], the optical microscopy  
based on laser-induced photoluminescence (UV–  
VIS-NIR) [13], the SrFe12O19@CTAB magnetic  
nanoparticles with electrothermal atomic absorption  
spectrometry (ET-AAS) [14-17], the colorimetric  
sensor [18], the electrothermal vaporization coupled  
with optical emission spectrometry with inductively  
coupled plasma (ETV-ICP-OES) [19] and laser-  
induced breakdown spectroscopy (LIBS) [20]  
were used for cadmium determination in various  
environmental samples. Due to the low concentration  
of cadmium in water samples and difficulty matrixes  
in wastewater samples, the pretreatment is required  
before the determination of cadmium by instrumental  
analysis. The different extraction methods such as,  
the ultrasound-assisted liquid–liquid spray extraction  
(USA-LLSE) [21], the solvent extraction [22], the  
liquid–liquid extraction [23], the cloud point assisted  
dispersive ionic liquid-liquid microextraction  
[24] the dispersive solid-phase extraction (DSPE)  
combined with ultrasound-assisted emulsification  
microextraction [25], solid-phase extraction  
(SPE) [26, 27], the coagulating homogenous  
dispersive micro solid-phase extraction exploiting  
graphene oxide nanosheets (CHD-µSPE)[28] and  
graphene oxide-packed micro-column solid-phase  
extraction[29] were used before cadmium analysis in  
water samples. Recently, the membrane micro solid-  
phase extraction procedure (M-μ-SPE) was reported  
as micro SPE (μ-SPE) for separation/determination  
of cadmium in water samples. This method showed  
several advantages, such as easy and fast extraction  
of cadmium in water samples. The properties of  
adsorbents have a main role for cadmium extraction  
by the syringe filter membrane micro solid-phase  
extraction procedure (SFM-μ-SPE). In this study, a  
novel sorbent based on CNTs@DHSP was used for  
extraction of Cd(II) in water and wastewater samples  
by SFM-μ-SPE at pH of 7. The proposed method was  
validated with CRM and spike samples in waters and  
high recovery was obtained by AT-FAAS.  
2. Experimental  
2.1. Material and Methods  
Atomtrapflameatomicabsorptionspectrophotometer  
(GBC 932, AT-FAAS, Aus) was used for cadmium  
determination in water and wastewater samples.  
The atom trap accessory /air-acetylene controlled  
by AVANTA software which was placed on the air-  
acetylene burner. The cadmium determines in water  
and wastewater samples with 1.0 mL of the sample  
with LOD of 0.025 mg L-1, the wavelength of 283.3  
nm and 5 mA. The lower limit of quantitation  
(LLOQ), ULOQ and linear range for AT-FAAS  
was obtained 100 µg L−1, 1800 µg L−1 and 100-  
1800 µg L−1, respectively. All water samples were  
injected by an auto-sampler to the injector of AT-  
FAAS for 1-1.5 min. The electrothermal atomic  
absorption spectrophotometer (ET-AAS) was  
used for the validation of water samples in ultra-  
trace analysis of Cd(II). The Metrohm pH meter  
was used for measuring pH in water samples (E-  
744, Switzerland). The shacking of water samples  
was used based on 250 rpm speeds by vortex  
mixer (Thermo, USA). The standard solution of  
cadmium (Cd2+) was purchased from Sigma Aldrich.  
(Germany) with a concentration of 1000 mg L-1 in  
1 % HNO3. The various concentration of cadmium  
was daily prepared by dilution of the standard Cd  
Cadmium extraction by CNTs@DHSP  
Jamshid Rakhtshah  
7
solution with DW. Ultrapure water was purchased  
from Millipore Company (USA) for the dilution  
of water samples. 2,3-Dimercapto-1-propanol  
(CASN:59-52-9, HOCH2CH(SH)CH2SH) was  
prepared from Sigma Aldrich, Germany. The pH  
was adjusted pH by 0.2 mol L-1 of sodium phosphate  
buffer solution (Merck, Germany) for a pH of 7.0  
(Na2HPO4/NaH2PO4). The analytical grade of  
reagents such as HNO3, HCl, acetone, and ethanol  
were prepared from Merck, Germany. The syringe  
Whatman filter membrane (SFM) with glass  
microfiber pre-filter (100 nm, Anotop filters, SN:  
WHA68091112, D:10 mm, polypropylene housing  
polypropylene membrane) was purchased from  
Sigma Aldrich, Germany. Anotop syringe filters  
contain the proprietary alumina and use for difficult  
separation samples.  
mixture, drop by drop, at room temperature. After  
sonicating for 15 min, the resulting mixture was  
refluxed at 60 °C under N2 atmosphere to remove  
the produced HCl. In order to obtain the CNTs@Cl,  
it was dried at 100 °C under vacuum. Then, 1 g of  
CNTs@Cl and 1 mL of DMP were mixed in 60 mL  
ethanol using an ultrasonic bath for 30 min. Then, a  
few drops of triethylamine were added to the above  
slurry, and the mixture was refluxed at 60 °C for  
three extra hours. The product was separated from  
the reaction mixture by a PTFE membrane filter and  
washed with ethanol three times and finally dried  
under vacuum at 100 °C.  
2.4. Extraction Procedure  
By SFM-μ-SPE procedure, 20 mL of water and  
standard samples (3 µg L−1 and 90 µg L−1) were  
used for the separation and determination of  
cadmium ions at pH 7. Firstly, the CNTs@DHSP  
added to water or cadmium standard solution  
and shaked for 3 min at pH=7. Then, the water  
sample was slowly passed through SFM with  
glass microfiber pre-filter and the solid-phase was  
separated by filtering (100 nm, polypropylene  
housing polypropylene membrane). After shaking,  
the Cd(II) ions were extracted by sulfur group of  
CNTs@DHSP as coordination bond or dative bond  
at pH from 6-8 (Cd2+→: SH @CNTs) and then the  
Cd (II) ions on SFM/CNTs@DHSP back-extracted  
by 0.5 mL of eluent (1.5 M, HNO3) at pH 2. Finally,  
the cadmium concentration in remained solution  
was determined by AT-FAAS after dilution with  
DW up to 1 mL (Fig.1). The procedure was used  
for a blank solution without cadmium ten times.  
The calibration curve for Cd in standards solutions  
was prepared (3- 90 µg L−1) and enrichment factor  
(EF) was calculated. The analytical parameters  
showed in Table 1. Validation of methodology  
was achieved by CRM for cadmium samples  
and ETAAS analysis. The recovery was obtained  
for cadmium by equation 1. The Cp and Cf is the  
primary and final concentration of Cd(II), which  
was determined by SFM-μ-SPE procedure coupled  
to AT-FAAS (n=10, Eq. 1).  
2.2. Human sample preparation  
The glass analysis was washed with a HNO3 solution  
(1 M) for at least 12 h and rinsed 10 times with DW.  
The cadmium concentrations in water and wastewater  
have a low concentrations less than 50 µg L-1 and low  
contamination for sampling and determination caused  
to low accuracy of results. By procedure, 20 mL of  
the water samples were prepared from well water,  
drinking water and wastewater factories from Iran.  
Clean syringes were prepared for sample treatment.  
The water is prepared and stored by standard method  
for sampling from water by adding nitric acid to waters.  
2.3. Synthesis of CNTs@DHSP adsorbent  
First, the CNTs@COOH was prepared according to  
the acid oxidation method reported in the literature  
[30]. In the final step, 1 g of CNTs@COOH was  
added in 50 mL of methanol and maintained  
under ultrasonic conditions for 15 min. Sodium  
borohydride was also simultaneously added to the  
solution. Then, the mixture was stirred at room  
temperature for 3 h. Then, the product was washed  
with methanol three times and dried under vacuum.  
Typically, CNTs@OH (0.5 g) and dry xylene (40  
mL) were sonicated for 15 minutes in a 100 mL  
round-bottomed flask. 3 mL of (3-chloropropyl)  
trimethoxysilane (CPTMS) was added to the above  
Re (%) = (Cp-Cf)/Cp×100  
(Eq.1)  
Anal. Method Environ. Chem. J. 4 (1) (2021) 5-15  
8
Table 1. The analytical features for determination cadmium by SFM-μ-SPE procedure  
Features  
Working pH  
value  
6-8  
Amount of CNTs@DHSP (mg)  
20.0  
Sample volume of water (mL)  
20 .0  
Volume of sample injection (mL)  
1.0  
Linear range for water (μg L-1)  
working range for water (μg L-1)  
Mean RSD %, n=10  
3.0-90  
3.0-170  
1.5  
LOD (μg L-1)  
0.75  
Enrichment factor for water  
Volume and concentration of HNO3  
Shaking time  
19.6  
1 mL, 1.5 M  
3.0 min  
R2 = 0.9998  
Correlation coefficient  
Fig. 1. Cadmium extraction in water sample based on CNTs@DHSP by SFM-μ-SPE procedure  
functionalized CNTs were functionalized by  
(3-chloropropyl) trimethoxysilane (CPTMS) to  
provide chloroalkylsilane. Finally, thiol derivative  
as a DHSP was covalently immobilized on CNTs.  
Finally, SH group of DHSP on the surface of CNTs  
can be complexed with cadmium ions in a water  
solution (Fig.2).  
3. Results and discussion  
3.1. Extraction Mechanism  
The carboxylic acid-functionalized CNTs were  
synthesized by using the acid oxidation method.  
Then, for the generation of OH groups on surface  
CNT, these materials were treated with sodium  
borohydride in methanol. Afterward, hydroxyl-  
Cadmium extraction by CNTs@DHSP  
Jamshid Rakhtshah  
9
Fig. 2. The extraction mechanism of cadmium by CNTs@DHSP  
Fig.3a. SEM image of CNTs@DHSP  
Fig.3b. TEM image of CNTs@DHSP  
3.2. SEM and TEM analysis  
3.3. Optimization of cadmium extraction SFM-  
The nanotubes of CNTs syntheses in University  
of Tabriz (Iran) and used for the synthesis of  
μ-SPE procedure  
The SFM-μ-SPE procedure based on novel CNTs@  
DHSP was optimized for cadmium extraction in  
water samples. So, different parameters such as  
pH, CNTs@DHSP Mass, eluent, sample volume  
and sonication time were studied.  
2,3-dimercapto-1-propanol  
immobilized  
on  
CNTs (CNTs@DHSP). The Scanning Electron  
Microscopy (SEM) and Transmission Electron  
Microscopy (TEM) of CNTs@DHSP showed low  
nanoparticles size between 40-100 nm which was  
shown in Figures 3a and 3b.  
Anal. Method Environ. Chem. J. 4 (1) (2021) 5-15  
10  
3.3.1.The effect of pH  
3.3.2. Effect of CNTs@DHSP mass  
The effect of various pH was studied from 2 to  
10 for Cd(II) extraction in water samples. The  
results showed the CNTs@DHSP can be removed  
cadmium ions from water samples at pH between  
6 to 8. Moreover, the efficient extraction was  
achieved for cadmium ions at pH=7 (> 95%) and  
the recoveries reduced at 6>pH and pH>8.5. So, the  
pH of 7.0 was used as optimum pH for cadmium  
extraction in waters for further works (Fig. 4).  
The mechanism of cadmium extraction depended  
on the coordination bond or dative covalent bond  
of the thiol group in CNTs@DHSP adsorbent  
(Cd→:SH). The positively charge of Cd2+ adsorbed  
on the surface of adsorbent with negative charge at  
optimized pH. At low pH (pH< pHPZC), the surface  
of CNTs@DHSP has a positive charge. Therefore,  
low recovery is related to the electrostatic repulsion  
between Cd2+ and positive charge of CNTs@DHSP.  
In addition, at a pH of 7, the surface of CNTs@  
DHSP have negatively charged and absorbed Cd2+.  
Also, in the pH>8.5, the Cd ions participated as OH  
group and the recovery was decreased.  
The efficient extraction was obtained by optimizing  
of CNTs@DHSP mass in pH=7. Therefore,  
the various of CNTs@DHSP mass was studied  
between 5-50 mg for Cd(II) extraction by SFM-  
μ-SPE procedure. The results showed us, a high  
recovery of more than 95% was achieved for 18  
mg of CNTs@DHSP in water samples. So, 20 mg  
of CNTs@DHSP as optimum adsorbent mass was  
used for the experimental run. (Fig. 5). Based on  
Figure 6, The higher amount of CNTs@DHSP had  
no effect on cadmium recovery.  
3.3.3. Effect of eluent and sample volume on  
cadmium extraction  
The volume and concentration of eluent for back  
extraction cadmium ions from SFM/CNTs@  
DHSP adsorbent were optimized at pH=7. Acidic  
pH dissociated thiol binding to cadmium and  
caused to release of free cadmium ions into the  
eluent phase. The different acid solution such as  
HCl, HNO3, NaOH and H2SO4, was selected for  
back-extraction of cadmium from SFM/CNTs@  
Fig. 4. The effect of pH on cadmium extraction based  
on CNTs@DHSP by SFM-μ-SPEprocedure  
Cadmium extraction by CNTs@DHSP  
Jamshid Rakhtshah  
11  
Fig. 5. The effect of CNTs@DHSP amount on cadmium extraction  
by SFM-μ-SPE procedure  
DHSP adsorbent. The results showed that 1.5 mol  
L-1 HNO3 was quantitatively back-extracted the  
cadmium from SFM/CNTs@DHSP adsorbent. The  
sample volume between 1-100 mL for cadmium  
extraction was studied in water samples by SFM-  
μ-SPE procedure. For optimization, the cadmium  
concentration ranges (3-90 µg L-1) based on 20 mg  
of CNTs@DHSP adsorbent were examined by the  
proposed procedure. The results showed us the high  
recoveries were achieved 25 mL of water samples  
at pH=7. Therefore, 20 mL of water was used as the  
optimal value for further study.  
The absorption capacities of cadmium for CNTs@  
DHSP and CNTs adsorbents were evaluated in  
optimized conditions. First, 20 mg of CNTs@  
DHSP or CNTs adsorbents added to 20 mL of water  
sample (standards cadmium solution: 200 mg L-1)  
at pH 7. After sonication for 20 min, the cadmium  
extracted on the CNTs@DHSP or CNTs adsorbents  
at optimizing pH. The cadmium concentration in  
the liquid phase is directly determined as the final  
cadmium concentration after adsorption processes.  
The results showed the adsorption capacity for the  
CNTs@DHSP or CNTs adsorbents was obtained  
152.6 mg g-1 and 19.7 mg g-1, respectively.  
3.3.4. Effect of sonication time and adsorption  
capacity  
3.3.5. Interference of coexisting ions  
Theeffectofinterferenceionsoncadmiumextraction  
based on CNTs@DHSP adsorbent in water samples  
was studied by SFM-μ-SPE procedure. The various  
interfering ions were added to 20 mL of cadmium  
solution (ULOQ: 90 μg L-1) at pH 7. Based on  
results the most of the probable concomitant ions  
have no effect on the extraction recovery of Cd(II)  
ions in optimized conditions (Table 2).  
The extraction time depended on the dispersion  
of nanoparticles CNTs@DHSP adsorbent in the  
water samples and caused to increase interaction  
between HS with Cd(II) at pH=7. The effect of  
sonication time was studied from 0.5 to 5 min. It  
was observed that the sonication of 3.0 min had  
favorite extraction for cadmium in water samples.  
Anal. Method Environ. Chem. J. 4 (1) (2021) 5-15  
12  
Table 2. The effect of interferences ions on cadmium extraction in water samples  
by SFM-μ-SPE procedure  
Mean ratio (CI /C Cd(II)  
Cd(II)  
)
Recovery (%)  
Cd(II)  
Interfering Ions (I)  
Al3+, V3+  
600  
900  
96.8  
08.0  
99.2  
Zn2+, Cu2+  
I- , Br-, F-, Cl-  
1200  
Na+, K+  
Ca2+, Mg2+  
1000  
900  
98.4  
97.7  
CO32-, PO43-  
1000  
97.2  
Co2+ , Mn2+, Sn2+  
Ni2+  
NH4+, NO3-  
350  
150  
800  
98.3  
96.7  
98.5  
Hg2+  
100  
97.4  
3.3.6. Real samples analysis  
procedure could be efficiently extracted/determined  
cadmium in water samples (Table 3). Due to results,  
thehighrecoveryforextractioncadmiuminwaterand  
wastewater samples was achieved by nanoparticles  
of CNTs@DHSP. Moreover, the certified reference  
materials (NIST; CRM) were used for validating  
results by the SFM-μ-SPE procedure (Table 4). Also,  
the results were validated by ET-AAS analysis which  
was compared to SFM-μ-SPE/AT-FAAS (Table 5).  
The separation and determination of cadmium in  
water samples was done based on CNTs@DHSP  
adsorbent by the SFM-μ-SPE procedure. The results  
showed us, the cadmium was efficiently extracted by  
the thiol group of CNTs@DHSP adsorbent in water  
samples at pH=7. By spiking water samples, the  
accuracy of the results was satisfactorily validated  
at optimized pH and confirmed that the SFM-μ-SPE  
Table 3. Validation of SFM-μ-SPE/AT-AAS procedure for Cd(II) determination in waters  
by spiking of real samples  
Sample*  
Water A  
Added(μg L-1)  
*Found (μg L-1)  
Recovery (%)  
---  
4.0  
---  
4.23 ± 0.18  
8.14 ± 0.31  
2.03 ± 0.09  
3.98 ± 0.21  
ND  
---  
97.8  
---  
Water B  
2.0  
---  
2.0  
---  
97.5  
---  
96.5  
---  
Water C  
1.93 ± 0.08  
50.75 ± 1.23  
Wastewater A  
40  
---  
40  
---  
30  
88.83 ± 2.64  
48.32 ± 1.87  
89.56 ± 3.45  
29.56 ± 1.34  
57.95 ± 2.08  
95.2  
---  
Wastewater B  
Wastewater C  
103.1  
---  
94.6  
*Mean of three determinations of samples ± confidence interval (P = 0.95, n =5)  
WaterA: Varamin River; Water B: Karaj River; Water C: drinking water Tehran; WastewaterA: Paint Factory of Karaj; Wastewater  
B: Petrochemical waste; Wastewater C: Chemical Factory in Industrial Varamin Co.  
Cadmium extraction by CNTs@DHSP  
Jamshid Rakhtshah  
13  
Table 4. Validation of SFM-μ-SPE procedure for cadmium determination  
by certified reference materials in waters (CRM, NIST)  
Sample  
conc.( μg L-1)  
Added  
Found*( μg L-1)  
Recovery (%)  
SRM 1643f  
5.89 ± 0.13  
-----  
5.0  
5.82 ± 0.16  
10.79 ± 0.25  
48.77 ± 1.42  
87.64 ± 2.61  
-----  
99.4  
-----  
97.2  
SRM 3108  
50.10 ± 1.1  
-----  
40  
*Mean of three determinations of samples ± confidence interval (P = 0.95, n =10)  
SRM 3108: Certified Cadmium Mass Fraction: 10.007 mg g-1 ± 0.027 mg g-1 dissolved in 1 L DW (C=10 mg L-1),  
make by dilution DW up to 0.05 mg L-1.  
Table 5. Comparing of SFM-μ-SPE procedure with ET-AAS for cadmium determination in water samples  
Sample  
Added ( μg L-1)  
ET-AAS* ( μg L-1)  
4.18 ± 0.17  
-----  
AT-FAAS*( μg L-1)  
4.06 ± 0.13  
7.98 ± 0.24  
2.18 ± 0.08  
4.09± 0.16  
aND  
Recovery (%)  
-----  
Water A  
-----  
4.0  
98.0  
Water B  
-----  
2.0  
2.12 ± 0.11  
-----  
-----  
95.5  
Water C  
-----  
2.0  
0.25 ± 0.02  
-----  
-----  
1.97 ± 0.09  
5.94 ± 0.18  
11.03± 0.34  
98.5  
Well water  
-----  
5.0  
6.12 ± 0.28  
-----  
-----  
101.8  
*Mean of three determinations of samples ± confidence interval (P = 0.95, n =10)  
a ND: Not Detected  
4. Conclusions  
6. References  
A novel CNTs@DHSP nanostructure was used for  
cadmiumextraction/separation/determinationinwater  
samples by the SFM-μ-SPE method coupled with  
AT-FAAS. By the proposed procedure, the efficient/  
easy/fast extraction for cadmium was obtained in a  
short time at pH=7. The CNTs@DHSP nanostructure  
has excellent recovery for Cd(II) extraction without  
any chelating ligands. The procedure had many  
advantages such as reusability of adsorbent, fast/easy  
pretreatment and a wide linear range for determination  
cadmium in waters. Therefore, the CNTs@DHSP  
nanostructure can be used as the favorite methodology  
for the determination and separation of cadmium in  
water samples by AT-FAAS.  
[1] L.T. Friberg, G.G. Elinder, T. Kjellstrom, G.F.  
Nordberg, Cadmium and Health:Atoxicological  
and epidemiological appraisal, CRC Press:  
Boca Raton, FL, USA, Vol. 2, 2019.  
[2] M.R. Rahimzadeh, S. Kazemi, A.A.  
Moghadamnia, Cadmium toxicity and  
treatment, Caspian J. Intern. Med., 8 (2017)  
135–145.  
[3] A.A. Tinkov, T. Filippini, O.P. Ajsuvakovae,  
M.G. Skalnaya, J.Aasethf, G. Bjørklundh, E.R.  
Gatiatulinai, E.V. Popova, O.N. Nemereshinai,  
P.T. Huangk, Cadmium and atherosclerosis:  
A review of toxicological mechanisms and  
a meta-analysis of epidemiologic studies,  
Environ. Res., 162 (2018) 240–260.  
5. Acknowledgements  
[4] M.S. Sinicropi, A. Caruso, A. Capasso,  
C. Palladino, A. Panno, C. Saturnino,  
Heavy metals: toxicity and carcinogenicity,  
Pharmacol., 2 (2010) 329–333.  
The authors wish to thank from Department  
of Inorganic Chemistry, Faculty of Chemistry,  
University of Tabriz, Tabriz, Iran, for supporting  
this work.  
Anal. Method Environ. Chem. J. 4 (1) (2021) 5-15  
14  
[5] S. Satarug, Dietary cadmium intake and its [15] M. Arjomandi, H. Shirkhanloo, A review:  
effects on kidneys, Toxics, 6 (2018) 15.  
[6] A.E. Nielsen, A. Bohr, M. Penkowa, The  
balance between life and death of cells: Roles  
Analyticalmethodsforheavymetalsdetermination  
in environment and human samples, Anal.  
Methods Environ. Chem. J., 2 (2019) 97-126.  
of metallothioneins, Biomark. Insights, 1 [16] H. Shirkhanloo, S. A. H. Mirzahosseini, N.  
(2007) 99–111.  
Shirkhanloo, The evaluation and determination  
of heavy metals pollution in edible vegetables,  
water and soil in the south of Tehran, province  
by GIS, Arch. Environ. Prot., 41 (2015) 63-72.  
[7] G. Gobe, D. Crane, Mitochondria, reactive  
oxygen species and cadmium toxicity in the  
kidney, Toxicol. Lett., 198 (2010) 49–55.  
[8] T.Bora,J.Dutta,Applicationsofnanotechnology [17] M. Aliomrani, M.A. Sahraian, H. Shirkhanloo,  
in wastewater treatment—A review, Nanosci.  
Nanotechnol., 14 (2014) 613–626.  
M. Sharifzadeh, Blood concentrations of  
cadmium and lead in multiple sclerosis  
patients from Iran, Iran. J. Pharm. Res., 15 (4),  
825 2016  
[9] L. Zhang, Q. Lei, Y. Cheng, Y. Xie, H. Qian, Y.  
Guo, Y. Chen, W. Yao, Study on the removal of  
cadmium in rice using microbial fermentation [18] J. Charoensuk, J. Thonglao, B. Wichaiyo,  
method, J. Food Sci., 82 (2017) 1467–1474.  
[10] International Agency for Research on Cancer  
(IARC), Monographs on the evaluation of  
the carcinogenic risks to human’s beryllium,  
cadmium, mercury and exposures in the glass  
A simple and sensitive colorimetric sensor  
for cadmium (II) detection based on self-  
assembled trimethyl tetradecyl ammonium  
bromide and murexide on colloidal silica,  
Microchem. J., 160 (2021) 105666.  
manufacturingIndustry, scientificpublications: [19] N. S.Medvedev, O. V. Lundovskaya, A. I.  
Lyon, France, pp. 119–238, 1993.  
Saprykin,Directanalysisofhigh-puritycadmium  
by electrothermal vaporization-inductively  
coupled plasma optical emission spectrometry,  
Microchem. J., 145 (2019) 721-755.  
[11] World Health Organization(WHO), Evaluation  
of certain food additives and contaminants,  
Thirty-third report of the joint FAO/WHO  
expert committee on food additives, technical [20] Y. Liu, Y. Chu, Z. Hu, S. Zhang, High-sensitivity  
ipcs/publications/jecfa/reports/en/index.html  
[12] N. Altunay, A. Elik, Ultrasound-assisted  
alkanol-based nanostructured supramolecular  
determination of trace lead and cadmium in  
cosmetics using laser-induced breakdown  
spectroscopy  
with  
ultrasound-assisted  
extraction, Microchem. J., 158 (2020) 105322.  
solvent for extraction and determination [21] H. Kaw, J. Li, X. Jin, Ultrasound-assisted  
of cadmium in food and environmental  
samples: Experimental design methodology,  
Microchem. J., 164 (2021) 105958.  
liquid–liquid spray extraction for the  
determination of multi-class trace organic  
compounds in high-volume water samples,  
Analyst, 143 (2018) 4575-4584.  
[13] E. M. Angelin, M. Ghirardello, The multi-  
analytical in situ analysis of cadmium-based [22] E. Bidari, M. Irannejad, M. Gharabaghi,  
pigments in plastics, Microchem. J., 157 (2020)  
105004.  
Solvent extraction recovery and separation of  
cadmium and copper from sulphate solution, J.  
Environ. Chem. Eng., 1 (2018) 1269–1274.  
[14] V. MortazaviNik, E. Konoz, A. Feizbakhsh,  
A. A. M. Sharif, Simultaneous extraction of [23] S.S. Swain, B. Nayak, N. Devi, S. Das,  
chromium and cadmium from bean samples by  
O19@CTAB magnetic nanoparticles and  
N. Swain, Liquid–liquid extraction of  
cadmium(II) from sulfate medium using  
phosphonium and ammonium based ionic  
liquids diluted in kerosene, Hydrometallurgy,  
162 (2016) 63–70.  
SrFe12  
determination by ETAAS: An experimental  
design methodology, Microchem. J., 159  
(2020) 105588.  
Cadmium extraction by CNTs@DHSP  
Jamshid Rakhtshah  
15  
[24] H.Shirkhanloo,M.Ghazaghi,M.M.Eskandari,  
Cloud point assisted dispersive ionic liquid-  
liquidmicroextractionforchromiumspeciation  
in human blood samples based on isopropyl  
2-[(isopropoxycarbothiolyl) disulfanyl, Anal.  
Chem. Res., 10 (2016) 18-27.  
[30] M. B. Hossein Abadi, H. Shirkhanloo, J.  
Rakhtshah, The evaluation of TerphApm@  
MWCNTs as a novel heterogeneous sorbent  
for benzene removal from air by solid phase  
gas extraction, Arab. J. Chem. 13 (2020)  
1741-1751.  
[25] M. Sadeghi, E. Rostami, D. Kordestani,  
H. Veisi, M. Shamsipur, Simultaneous  
determination of ultra-low traces of lead and  
cadmium in food and environmental samples  
using dispersive solid-phase extraction  
(DSPE) combined with ultrasound-assisted  
emulsification microextraction based on  
the solidification of floating organic drop  
(UAEME-SFO) followed by GFAAS, RSC  
Adv., 7 (2017) 27656–27667.  
[26] E. Yilmaz, I. Ocsoy, Bovine serum albumin-  
Cu(II) hybrid nanoflowers: An effective  
adsorbent for solid phase extraction and  
slurry sampling flame atomic absorption  
spectrometric analysis of cadmium and lead  
in water, hair, food and cigarette samples,  
Anal. Chim. Acta, 906 (2016)110-117.  
[27] H. Shirkhanloo, A. Khaligh, F. Golbabaei,  
Z. Sadeghi, A. Vahid, A. Rashidi, On-line  
micro column preconcentration system  
based on amino bimodal mesoporous silica  
nanoparticles as a novel adsorbent for  
removal and speciation of chromium (III, VI)  
in environmental samples, J. Environ. Health  
Sci. Eng., 13 (2015) 1-12.  
[28] M. Ghazaghi, H. Z. Mousavi, A. M. Rashidi,  
H. Shirkhanloo, R. Rahighi, Innovative  
separation and preconcentration technique  
of coagulating homogenous dispersive micro  
solid phase extraction exploiting graphene  
oxide nanosheets, Anal. Chim. Acta, 902  
(2016) 33-42.  
[29] H. Shirkhanloo, A. Khaligh, H.Z. Mousavi,  
A. Rashidi, Graphene oxide-packed micro-  
column solid-phase extraction combined with  
flame atomic absorption spectrometry for  
determination of lead (II) and nickel (II) in  
water samples, Int. J. Environ. Anal. Chem.,  
95 (2015) 16-32.  
Anal. Method Environ. Chem. J. 4 (1) (2021) 16-25  
Research Article, Issue 1  
Analytical Methods in Environmental Chemistry Journal  
AMECJ  
Development of electrochemical sensor based on carbon  
paste electrode modified with ZnO nanoparticles for  
determination of chlorpheniramine maleate  
Hamideh Asadollahzadeh a,*  
aDepartment of Chemistry, Faculty of Science, Kerman branch, Islamic Azad University, Kerman, Iran, P. O. Box  
7635131167, Kerman, Iran  
A R T I C L E I N F O :  
Received 12 Dec 2020  
Revised form 3 Feb 2021  
Accepted 28 Feb 2021  
A B S T R A C T  
Zinc oxide (ZnO) nanoparticles with an average size of 60 nm have  
been successfully prepared by microwave irradiation. Carbon paste  
electrode (CPE) was modified with ZnO nanoparticles and used for  
the electrochemical oxidation of chlorpheniramine maleate (CPM).  
Cyclic voltammetry (CV) study of the modified electrode indicated  
that the oxidation potential shifted towards a lower potential by  
approximately 106 mV and the peak current was enhanced by 2 fold  
in comparison to the bare CPE (ZnO/CPE-CV). The electrochemical  
behaviour was further described by characterization studies of scan  
rate, pH and concentration of CPM. Under the optimal conditions  
the peak current was proportional to CPM concentration in the  
range of 8.0 ×10-7 to 1.0 × 10-3 mol L-1 with a detection limit of 5.0  
× 10-7 mol L-1 by differential pulse voltammetry (DPV). The peak  
current of CPM is linear in the concentration range of 0.8 - 1000  
µM (R2=0.998). The ZnO/CPE has a good reproducibility and high  
stability for the determination of CPM using this electrode. The  
proposed method was successfully applied to the determination of  
CPM in pharmaceutical samples. In addition, the important analytical  
parameters were compared with other methods which show that ZnO/  
CPE-CV procedure are comparable to recently reported methods.  
Available online 28 Mar 2021  
------------------------  
Keywords:  
Chlorpheniramine maleate,  
Pharmaceutical determination,  
Carbon paste electrode,  
Cyclic voltammetry,  
ZnO nanoparticles  
antagonist has been used to treat allergies such  
1. Introduction  
as hay fever, and other respiratory tract allergies  
[1]. The common side effects of chlorpheniramine  
(CPM, CP) include sleepiness, restlessness, and  
weakness dry mouth and wheeziness. CPM/CP is  
often combined with phenylpropanolamine to form  
an allergy medication with both antihistamine and  
decongestant properties,CPM/CPisapartofaseriesof  
antihistamines including pheniramine (Naphcon).  
As previous work, the CPM/CP synthesized  
through pyridine based on alkylation by  
4-chlorophenylacetonitrile. The CPM generated by  
alkylating with 2-dimethylaminoethylchloride in  
Antihistamines are a class of drugs commonly used  
to treat symptoms of allergies. These drugs help  
treat conditions caused by too much histamine, a  
chemical created by your body’s immune system.  
Chlorpheniramine maleate [3-(4-chlorophenyl)-  
N,N-dimethyl-3-pyridin-2-yl-propan-1-amine,  
CPM] is an alkyl amine antihistamine. For  
more than 30 years, the CPM as a H1-receptor  
*Corresponding Author: Hamideh Asadollahzadeh  
CPE-ZnO nanoparticles for CPM determination  
Hamideh Asadollahzadeh  
17  
Schema 1. Synthesis of CPM/CP based on alkylation by pyridine  
the presence of sodium amide (Schema 1). Several  
methods have been reported for the determination  
of CPM maleate including, spectrophotometry [2],  
liquid chromatography [3], liquid chromatography-  
massspectrometry[4],gaschromatography[5],high  
performance liquid chromatography [6]. However,  
these instrumental methods have suffered some  
disadvantages such as time consuming, solvent-  
usage intensive and requires expensive devices  
and maintenance [7]. The electrochemical methods  
using chemically modified electrode have been  
widely used in sensitive and selective analytical  
methods for the detection of the trace amounts  
of biologically important compounds. Electrode  
surface may be changed with metal nanoparticles  
and such surfaces have found various applications  
within the sector of bio electrochemistry,  
particularly in biosensors. it’s also been observed  
that nanoparticles can act as conductivity centers  
facilitating the transfer of electrons. Additionally,  
they provide large catalytic area. Several types of  
nanoparticles, including metal nanoparticles [8-  
10], oxide nanoparticles [11-13], semiconductor  
nanoparticles and even composite nanoparticles  
[14-16] are widely utilized in electrochemical  
sensors and bio sensors [17]. Some electrochemical  
methods are also reported for the determination of  
CPM by voltammetry [18-21]. Electrochemical  
sensors satisfy many of the requirements for such  
tasks particularly owing to their inherent specificity,  
rapid response, sensitivity and simplicity of  
preparation [18]. To our knowledge, no study has  
reported the electrocatalytic oxidation of CPM by  
using ZnO modified carbon paste electrode. Thus,  
in the present work, the ZnO nanoparticle have been  
synthesized using microwave irradiation process  
and a modified carbon paste electrode is fabricated  
by using ZnO nanoparticles for the determination  
of CPM. All results were validated by spiking  
samples and compared to other methods.  
2. Experimental  
2.1. Chemicals and Reagents  
Pure CPM, sodium dihydrogen ortho phosphate  
(NaH2PO4), disodium hydrogen phosphate  
(Na2HPO4), sodium phosphate (Na3PO4),  
orthophosphoric  
acid  
(H3PO4),  
sodium  
hydroxide (NaOH), hydrochloric acid (HCl),  
Zn(NO3)2.4H2O and graphite powder were  
obtained from Merck. The buffer solutions were  
prepared from orthophosphoric acid and its  
salts in the pH range of 8 to 11. All the aqueous  
solutions were prepared by using double distilled  
water. High viscosity paraffin (d =0.88 kg L−1)  
from Merck was used as the pasting liquid for  
the preparation of the carbon paste electrodes.  
2.2. Apparatus  
Electrochemical studies were performed using  
a Metrohm polarograph potentiostat-galvanostat  
(Metrohm Computrace 797-VA). The 797 VA is a  
voltammetric measuring stand that is connected  
to a PC. The computer software provided controls  
the measurement, records the measured data and  
evaluates it. Operation is most straightforward  
due to the well-laid-out structure of the program.  
The integrated potentiostat with galvanostat  
guarantees the highest sensitivity with reduced  
noise. Voltammetry system for the determination  
of organic additives in electroplating baths with  
Anal. Method Environ. Chem. J. 4 (1) (2021) 16-25  
18  
cyclic voltammetric stripping (CVS). Complete  
accessories with VA Computrace software and  
all electrodes for a complete measurement  
system: Rotating platinum disk electrode  
(RDE), Ag/AgCl reference electrode and Pt  
auxiliary electrode. Three-electrode system  
consisted of a bare CP and ZnO/CPE electrode  
as the working electrode, Ag/AgCl (3M KCl) as  
the reference electrode and a platinum wire as  
the auxiliary electrode. A Metrohm 691 pH/Ion  
meter was used for pH measurements. Solutions  
were degassed with nitrogen for ten minutes  
prior to recording of the voltammogram. X-ray  
diffraction (XRD) patterns were recorded by a  
Philips-X’pertpro, X-ray diffractometer using  
Ni-filtered Cu Ka radiation in University of  
Kashan-Iran. Scanning electron microscopy  
(SEM) images were obtained from LEO  
instrument model 1455VP.  
long). Electrical contact was made by forcing  
a copper wire down into the tube. When  
necessary, a new surface was obtained by  
pushing out an excess of paste and polishing  
it on weighing paper. Unmodified CPE was  
prepared in the same way without adding of  
ZnO nanoparticles.  
2.5. Procedure and sample preparation  
20 pieces of CPM tablet (Daro pakhsh. Iran) were  
powdered in a mortar. A portion equivalent to a stock  
solution of a concentration of about 0.01 M was  
accurately weighed and transferred into a 100 mL  
calibrated flask and completed to the volume with  
double distilled water. The contents of the flask were  
sonicated for 10 min to affect complete dissolution.  
Appropriatesolutionswerepreparedbytakingsuitable  
aliquots of the clear supernatant liquid and diluting  
them with the phosphate buffer solutions. Also, 0.5 ml  
of an ampoule of CPM, according to its specifications,  
each ml of which contains 10 mg of the drug, was  
placed in a 25 ml calibrated flask and completed with  
a buffer at pH=10 and voltammetry was performed  
on it. The differential pulse voltammograms (DPV)  
were recorded between 0.4 and 1.2 V. The oxidation  
peak current of CPM was measured. The parameters  
for DPV were pulse width of 0.05 s, pulse increment  
of 4 mV, pulse period of 0.2 s, pulse amplitude of 50  
mV and scan rate of 50 mVs-1.  
2.3. Synthesis of ZnO nanoparticles  
In this work, zinc acetate and graphene powders  
were used as the starting reagent. 0.41 mol  
of Zn(NO3)2.4H2O was dissolved in 50 ml of  
deionized water under vigorous stirring. 1 ml of  
NaOH (1 M) was then added dropwise to the  
solution. Afterward, the solution was exposed by  
microwave irradiation with different powers and  
times. The microwave oven followed a working  
cycle of 30 s on and 70 s off (30 % power). After  
reaction in microwave the samples were cooled  
to room temperature naturally. Precipitates were  
washed with deionized water and ethanol, and  
air-dried at room temperature.  
3. Results and discussion  
3.1. XRD analysis  
The phase type, crystal structure and purity of  
the product obtained are determined by the XRD  
method. The XRD pattern of the as obtained ZnO  
nanoparticles as sample number 1 was shown in  
Figure 1. Peaks in this pattern are reported in the  
range of 2Ɵ from 20 to 80 degrees. Patterns of  
the samples were indexed as a cubic phase. The  
XRD results proved the high crystallinity and  
purity of the products synthesized by microwave  
method. According to XRD data, the crystalline  
size (Dc) of ZnO nanoparticles can be determined  
by using Debye- Scherrer formula. The obtained  
average particle size was found to be 60 nm.  
2.4. Preparation of bare carbon paste  
electrode and modified carbon paste electrode  
The modified carbon paste electrode was  
prepared by hand mixing 0.1 g of ZnO  
nanoparticles with 0.9 g graphite powder with  
a mortar and pestle. Then paraffin was added  
to the above mixture and mixed for 30 min  
until a uniformly wetted paste was obtained.  
This paste was then packed into the end  
of a glass tube (ca. 3.35 mm i.d. and 10 cm  
CPE-ZnO nanoparticles for CPM determination  
Hamideh Asadollahzadeh  
19  
Fig. 1. XRD patterns of ZnO nanoparticles sample 1  
3.2. Scanning electron microscopy  
the nucleation of the particles is increased, and  
since the particles have a very active surface,  
large and cohesive masses are obtained in all test  
conditions. Therefore, the sample prepared in 360  
W power and 4 min time due to the creation of  
nanoparticles in nanometer size according to the  
scale of images and homogeneous distribution  
is an optimized condition for time and power  
consumption to make ZnO nanoparticles. The  
produced ZnO nanoparticles have mean diameters  
of approximately 40-80 nm.  
In Figure 2 shows SEM image of ZnO powder  
obtained at 4 min and 360 W (sample no 1), at  
540 W (sample no 2) and 750 W (sample no 3). As  
can be seen from SEM images, at 360 power, the  
reaction is faster due to the generation of more free  
radicals in solution and increased heat production  
due to the rotation of these active species. The  
formed nanoparticles have relatively smaller sizes  
and better distribution. At 540 and 720 W, due to  
the very high energy produced in these powers,  
Fig. 2. SEM images of the ZnO nanoparticles for a) sample no. 1, b) sample no. 2, c) sample no. 3  
Anal. Method Environ. Chem. J. 4 (1) (2021) 16-25  
20  
3.3. Electrochemical behavior of CPM at the  
ZnO/CPE  
3.4. Effect of pH  
The effect of pH of the solution on the  
electrochemical response of CPM was investigated  
from pH 8 to 11 (although lower pH was also  
examined in which the peak did not appear well).As  
can be seen in the Figure 4, with increasing pH, the  
anodic potential shifts to more negative potentials,  
which indicates better oxidation of the material  
at the electrode surface and the electrocatalytic  
effect. A linear relationship existed between the  
potential and pH in the range 8 to 11 (Fig. 5). The  
linear regression equation was E= -60.5pH+1582  
(R2=0.991). The slope of 59 mV/pH suggests that an  
equal number of protons and electrons are involved  
in the oxidation process. Also, with increasing pH,  
the peak current increases to 10 and at pH = 11,  
the current decreases, so pH = 10 is chosen as the  
optimal point.  
The electrochemical behavior of CPM has been  
studied in two electrodes. Cyclic voltammetry  
(CV) was applied to investigate the electrochemical  
behavior of 0.4 mM CPM in 0.1 M phosphate buffer  
at pH 10 with a bare CPE and ZnO/CPE. Figure  
3 shows the cyclic voltammograms in the CPE  
and ZnO/CPE electrode. As shown in this figure,  
in the presence of CPM, an irreversible oxidation  
peak at 1.093 V on the bare CPE attributed to the  
electrochemical oxidation of CPM. In the case of the  
ZnO /CPE, the oxidation peak of CPM decreased to  
0.987 V and the peak current increased by 2.0 times  
compared with that for the bare CPE. These results  
suggestedthatZnOobviouslyacceleratetheelectron  
transfer at the electrode surface and improve the  
electrochemical performance accordingly.  
Fig. 3. Cyclic voltammograms of CPE and ZnO/CPE at presence of 0.4 mM CPM in 0.1  
phosphate buffer solution (pH 10) at scan rate 50 mVs-1  
CPE-ZnO nanoparticles for CPM determination  
Hamideh Asadollahzadeh  
21  
Fig.4. a) Cyclic voltamogram of CPM at different pH b) Relationship between the peak potential of CPM and pH.  
Fig. 5. Cyclic voltammograms of ZnO/CPE in the presence of 0.2 mM of CPM in 0.1 phosphate  
buffer solution (pH 10) at different scan rates (from inner to outer): 30, 50, 70, 100, 130, 200  
½
and 300 mV s-1. Insets: b, peak current vs. square root of scan rate (v )  
Anal. Method Environ. Chem. J. 4 (1) (2021) 16-25  
22  
3.5. Effect of scan rate  
of CPM. The phosphate buffer solution of pH 10  
was selected as the supporting electrolyte for the  
quantification of CPM as it gave maximum peak  
current at pH 10. DPV obtained with increasing  
amounts of CPM showed that the peak current  
increased linearly with increasing concentration, as  
shown in Figure 6. Using the optimum conditions  
described previously, linear calibration curves  
The effect of scan rate on the electrocatalytic  
oxidation of CPM at the ZnO /CPE was  
investigated by cyclic voltammetry. As can be seen  
in the Figure 5a, the scanning potential increases  
the peak CPM oxidation shifts to more positive  
potentials, which imposes a kinetic constraint on  
the electrochemical reaction. Figure 5b illustrates  
that a linear relationship existed between the  
oxidation peak currents of CPM and the square root  
(v1/2) of the scan rate in the range from 30 to 300  
mVs-1, indicating a diffusion-controlled process.  
The linear regression equation was expressed as  
I(µA)= 24.597v1/2 -2.942 (R2 =0.991).  
were obtained for CPM in the range of in range  
-7  
of 8×10  
to 1×10-3 M. (Fig. 6 Inset). The linear  
equation I=0.159x+6.99 (R2=0.994).  
3.7. The repeatability and stability of the ZnO/CPE  
Repeatability of the ZnO/CPE was examined by the  
determination of 0.5 mM of CPM in 0.1 M phosphate  
buffer solution at pH=10 with the same electrode 5  
times. A relative standard deviation (RSD) value  
of 2.76% was observed, that indicating a good  
reproducibility of ZnO/CPE for CPM determination.  
Furthermore, the operational stability of ZnO/CPE  
was investigated by CV method every 2 days in 2  
weeks. Only a small decrease of current (about 3.5%)  
for 2 mM CPM was observed, which can be attributed  
to the good stability of the modified electrode.  
3.6. Calibration curve  
In order to develop a voltammetric method for  
determination of the drug, the DPV mode is selected,  
because the peaks are sharper and better defined at  
lower concentration of CPM than those obtained  
by cyclic voltammetry, with a lower background  
current, resulting in improved resolution.  
According to the obtained results, it was possible  
to apply this technique to the quantitative analysis  
Fig. 6. DPV obtained at a ZnO/CPE for different concentrations of CPM (0.8 to 1000 µM). Inset:  
linear relationship between the peak current and concentration of CPM, scan rate: 50 mV s-1  
CPE-ZnO nanoparticles for CPM determination  
Hamideh Asadollahzadeh  
23  
3.8. Analysis of real samples  
for ampoule. Recovery studies were carried out  
after the addition of known amounts of the drug  
to various preanalyzed formulations of CPM.  
The results are listed in Table 1. Analytical  
parameters obtained here were compared with  
results obtained by other methods which show  
that they are comparable or better than the values  
reported by other groups (Table 2).  
In order to evaluate the applicability of the  
proposed method in the real sample analysis, it  
was used to detect CPM in tablets and ampoule  
(4 mg per tablet and 10 mg/mL for ampoule)  
(Fig. 7). The results are in good agreement with  
the content marked in the label. The detected  
content was 4.06 mg per tablet with 95%  
recovery and 9.76 mg/mL with 101 %recovery  
Fig.7. DPV obtained at a ZnO/CPE for standard solution 0.0001M  
of CPM, tablet, ampoule and standard added with tablet sample.  
Table. 1. Determination of CPM in tablet and ampoule sample with ZnO/CPE by DPV method  
Amount CPM in  
sample (mg)  
Found in  
sample  
Added  
(mg)  
Deffected after Recovery  
Sample  
addition (mg)  
(%)  
Tablet  
4
4.06±0.08  
9.77±0.2  
2.74  
3.5  
2.62±0.1  
95.62  
106.3  
Ampoule  
10  
3.73±0.07  
Anal. Method Environ. Chem. J. 4 (1) (2021) 16-25  
24  
Table 2. Comparison of analytical parameters for determination of CPM with different analytical methods.  
Electrode  
Method  
LOD(µM)  
LR(µM)  
Ref  
CPE-ion exchanger  
CPE-SDS  
PM  
DPV  
CV  
0.51  
1.7  
1.2-10000  
1.0 – 800  
2.0 -45  
[18]  
[7]  
Ru/Pty/GCE  
0.338  
[19]  
MWCNT-modified GCE  
CPE- CO nanostructure  
CPE- ZnO Nanoparticle  
DPV  
DPV  
DPV  
1.63  
0.08  
0.50  
5.0-500  
0.1-10  
[20]  
[21]  
0.8–1000  
This work  
method for simultaneous determination  
of diphenhydramine, promethazine,  
4. Conclusions  
ZnO/CPE was successfully fabricated and has  
shown electrocatalytic effect on the oxidation  
of CPM. In Comparison with the bare CPE, the  
presence of small amounts of ZnO reduced the  
oxidation peak potential of CPM while increased  
the current response of CPM. The CPM peak  
current is linear from a concentration range of 0.8  
µM to 1000 µM with excellent R2 value of 0.998.  
The detection limit of this modified electrode was  
found to be 0.5 µM and a good reproducibility,  
high stability was obtained for the determination  
CPM using this electrode. The content of CPM  
in tablet and ampoule samples was successfully  
determined with ZnO/CPE, which indicated the  
modified electrode is useable for the determination  
of CPM concentration in real samples.  
chlorpheniramine and ephedrine in cold-  
cough syrups, Pharm. Chem. J., 51 (2017)  
153–158.  
[4] X. Chen, Y. Zhang, D. Zhong, Simultaneous  
determination of chlorpheniramine and  
pseudoephedrine in human plasma by liquid  
chromatography–tandem mass spectrometry,  
Biomed. Chromatogr., 18 (2004) 248-253.  
[5] M. E. Kaf Alghazal, F. Alrouh, Y. Bitar, S.  
Trefi, Determination of dimenhydrinate and  
chlorpheniramine maleate in pharmaceutical  
forms by new gas chromatography method,  
Res. J. Pharm. Technol., 12 (2019) 2851-  
2856.  
[6] MR. Louhaichi, S. Jebali, M. H. Loueslati,  
N. Adhoum, L. Monser, Simultaneous  
determination  
pheniramine,  
of  
pseudoephdrine,  
pyrilamine,  
5. Acknowledgement  
guaifenisin,  
The author is grateful to Islamic Azad University,  
Kerman Branch, for financial assistance of this  
work.  
chlorpheniramine and dextromethorphan  
in cough and cold medicines by high  
performance liquid chromatography, Talanta,  
78 (2009) 991-997.  
6. References  
[7] S. D. Lamani, R. N. Hegde, A. P. Savanur, S.  
T. Nandibewoor, Voltammetric determination  
of chlorpheniramine maleate based on the  
enhancement effect of sodium dodecyl sulfate  
at carbon paste electrode, Electroanal., 23  
(2011) 347-354.  
[1] K. D. Tripathi, in: Essentials of Medical  
Pharmacology, Jaypee Brothers, New Delhi,  
p. 140, 2004.  
[2] A. K. Kaura, V. Gupta, M. Kaura, G.S.Roy,P.  
Bansl, Spectrophotometric determination  
of CPM maleate and phenylpropanolamine  
hydrochloride by two wavelengths method, J.  
Pharm. Res., 7 (2013) 404-408.  
[8] Z. Amani-Beni, A. Nezamzadeh-Ejhieh, NiO  
nanoparticles modified carbon paste electrode  
as a novel sulfasalazine sensor, Anal. Chim.  
Acta, 1031 (2018) 47-59.  
[3] N. M. Njuguna, K. O. Abuga, F. N. Kamau,  
G. N. Thoithi, A liquid chromatography  
CPE-ZnO nanoparticles for CPM determination  
Hamideh Asadollahzadeh  
25  
[9] M. M. Vinay, Y. Arthoba Nayaka, Iron  
oxide (Fe2O3) nanoparticles modified carbon  
paste electrode as an advanced material for  
electrochemical investigation of paracetamol  
and dopamine, J. Sci. Adv. Mater. Devices,  
49 (2019) 442-450.  
[16] J. Zhao, P. Yue, S. Tricard, T. Pang, Y. Yang,  
T. Pang, Y. Yang, J. Fang, Prussian blue (PB)/  
carbon nanopolyhedra/polypyrrole composite  
as electrode: a high performance sensor to  
detect hydrazine with long linear range, Sens.  
Actuators B Chem., 251 (2017) 706-712.  
[17] E. S. Abood, A. M. Jouda, M. Mashkoor, Zinc  
metal at a new ZnO nanoparticles modified  
carbon paste electrode: A cyclic voltammetric  
study, Nano Biomed. Eng., 10 (2018) 149-  
155.  
[10] N. BAshoka, B. E. K Swamy, H. Jayadevappa,  
S. C. Sharma, Simultaneous electroanalysis of  
dopamine, paracetamol and folic acid using  
TiO2-WO3 nanoparticle modified carbon paste  
electrode, J. Electroanal. Chem., 859 (2020)  
113819  
[18] M. Hazem. Abu-Shawish, Potentiometric  
response of modified carbon paste electrode  
based on mixed ion-exchangers, Electroanal.,  
20 (2008) 491–497.  
[11] Gh. Karim-Nezhad, Z. Khorablou, M.  
Zamani, P. Seyed Dorraji, M. Alamgholiloo,  
Voltammetric  
sensor  
for  
tartrazine  
determination in soft drinks using poly  
(p-aminobenzenesulfonic acid)/zinc oxide  
nanoparticles in carbon paste electrode, J.  
Food Drug Anal., 25 (2017) 293-301.  
[19] E. A. Khudaish, M. Al-Hinaai, S. Al-Harthy,  
K. Laxman, Electrochemical oxidation of  
chlorpheniramine at polytyramine film doped  
with ruthenium (II) complex: Measurement,  
[12] O. J D’Souza, R. J Mascarenhas, A. K Satpati,  
B. M Basavaraja, A novel ZnO/reduced  
graphene oxide and Prussian blue modified  
carbon paste electrode for the sensitive  
determination of Rutin, Sci. China Chem., 62  
(2019) 262–270.  
kinetic  
Electrochim. Acta, 135 (2014) 319–326.  
[20] Z. Pourghobadi, R. Pourghobadi,  
and  
thermodynamic  
studies,  
Electrochemical behavior and voltammetric  
determination of chlorpheniramine maleate  
by means of multiwall carbon nanotubes  
modified glassy carbon electrode, Int. J.  
Electrochem. Sci., 10 (2015) 7241–7250.  
[21] M. Amiri, M. Alimoradi, K. Nekoueian, A.  
Bezaatpour, Cobalt flower-like nanostructure  
as modifier for electrocatalytic determination  
of chloropheniramine, Ind. Eng. Chem. Res.,  
51 (2012) 14384-14389.  
[13] A. M Fekry, M. Shehata, S. M. Azab, A.  
Walcarius, Voltammetric detection of caffeine  
in pharmacological and beverages samples  
based on simple nano-Co (II, III) oxide  
modified carbon paste electrode in aqueous  
and micellar media, Sens. Actuators B, 302  
(2020) 127172.  
[14] B. Su, H. Shao, N. Li, X. Chen, Z. Cai, X.  
Chen, A sensitive bisphenol A voltammetric  
sensor relying on AuPd nanoparticles/  
graphene composites modified glassy carbon  
electrode, Talanta, 166 (2017) 126-132.  
[15] A. Benvidi, M. T. Nafar, Sh. Jahanbani,  
M. DehghanTezerjani, M. Rezaeinasab, S.  
Dalirnasab, Developing an electrochemical  
sensor based on a carbon paste electrode  
modified with nano-composite of reduced  
graphene oxide and CuFe2O4 nanoparticles for  
determination of hydrogen peroxide, Mater. Sci.  
Eng. C Mater. Biol.Appl., 75 (2017) 1435-1447.  
Anal. Method Environ. Chem. J. 4 (1) (2021) 26-35  
Research Article, Issue 1  
Analytical Methods in Environmental Chemistry Journal  
AMECJ  
Novel graphite rod electrode modified with iron-  
functionalized nanozeolite for efficient wastewater treatment  
by microbial fuel cells  
Mostafa Hassania, Mohsen Zeeba*, Amirhossein Monzavib, Zahra Khodadadia and Mohammad Reza Kalaeec,d  
aDepartment of Applied Chemistry, Faculty of Science, Islamic Azad University, South Tehran Branch, Tehran, Iran  
bDepartment of Polymer and Textile Engineering, Islamic Azad University, South Tehran Branch, Tehran, Iran  
cDepartment of Polymer Engineering, Islamic Azad University, South Tehran Branch, Tehran, Iran  
dNanothecnology Research Center, Islamic Azad University,South Tehran Branch,Tehran, Iran  
A R T I C L E I N F O :  
Received 10 Nov 2020  
Revised form 14 Jan 2021  
Accepted 23 Feb 2021  
A B S T R A C T  
Microbial fuel cells (MFCs) are a green and efficient approach to treat  
wastewater and generate energy. According to the present research,  
a novel MFC fabricate based on graphite rod electrodes (GRE). The  
surface of this cathode was modified with iron-functionalized ZSM-  
5 nanozeolite. The characterization of Iron doping in nanozeolite  
structure and electrode surface modification were obtained by XRD  
and EDX analyzes, respectively. Chemical analysis of square wave  
(Sqw)andcyclicvoltammetry(CV)determinedforallofthreegraphite  
electrodes (G, G-Z and G-Z/Fe) with higher efficiency. Morover, the  
comparison of experimental results from 72-hour fuel cell steering  
was evaluated and showed that the G-Z/Fe graphite electrodes has  
maximum efficiency and effectiveness. Thus, the efficiency of fuel  
cell output current and residual chemical oxygen demand removal  
with this electrode increased up to 21.8% and 36.9%, respectively.  
The effiucient recovery for the modification of the graphite electrode  
surface was achieved due to increasing of the specific surface area,  
the active sites of functionalized nanozeolite and the elevation in the  
electrical conductivity through the presence of iron particles doped in  
the ZSM-5/Fe nanocatalyst structure. Therefore, the G-Z/Fe cathode  
can be used as a favorite electrode for the construction of MFCs based  
on GRE with high efficiency and economic.  
Available online 29 Mar 2021  
------------------------  
Keywords:  
Microbial Fuel Cells (MFCs),  
Graphite electrodes,  
Iron-functionalized ZSM-5 nanozeolit,  
Wastewater treatment  
methodforwastewatertreatment.MFCscandivided  
1. Introduction  
into two main categories, mediated and unmediated  
groups. The MFCs separated the compartments of  
the anode (oxidation) and the cathode (reduction).  
Most of MFCs use an organic electron donor that  
is oxidized to produce CO2, protons, and  
electrons. The cathode acts by different electron  
acceptors such as oxygen (O2). Other electron  
acceptors studied for metal treatment by reduction,  
nitrate reduction, and sulfate reduction in 25 °C  
and pH of 7 [2-4]. Microorganisms within an  
Microbial fuel cell (MFC) has different approach  
for wastewater treatment because the wastewater  
treatment process generates electricity or hydrogen  
gas instead of consuming electricity [1]. The  
MFC technology is depended on generating bio-  
electricity from bacterial biomass as the latest  
*Corresponding Author: Mohsen Zeeb  
Treatment of wastewater by G-Z/Fe electrode in MFCs  
Mostafa Hassani et al  
27  
MFC, can be decomposed the organic matter by  
oxidizing, produce electrons that pass through a  
series of respiratory enzymes inside the cell and  
produce energy for the cell in the form of ATP.  
Then. the electrons are released towards a final  
electron acceptor. This receptor captures and  
reduces the electrons. For example, oxygen can  
be converted to water by the catalytic reaction  
of electrons with proton [5]. Previous research  
on electrodes used catalytic adhesives, carbon  
with non-platinum catalysts, flat carbon, carbon-  
coated tube and bio electrodes in the fabrication  
of carbon-based cathodes. Therefore, this study  
employed a carbon rod electrode coated with ZSM-  
5/Fe nanocatalyst [6-8]. Zeolites are tetrahedral  
crystalline aluminosilicates bonded with oxygen  
bridges. Due to their SSA, the specific channel  
structure, high thermal and hydrothermal stability,  
they are widely used in industries such as chemistry  
and petrochemicals, and water and wastewater  
treatment [9-11]. As mentioned, extensive research  
has been performed throughout the world to make  
fuel cells exploiting new electrodes.The researchers  
developed a cathode made of nickel-doped reduced  
nanographene as well as acid-hydroionized  
reduced nanographene to determine and evaluate  
the efficiency of the power output density with  
each of these electrodes. According to the results,  
the acid-hydroionized reduced nanographene  
showed the higher power output density (37%)  
than the nickel-doped reduced nanographene [12].  
In another study, the researchers were developed a  
triple nanocomposite cathode containing graphene  
oxide, polyethylene dioxythiophene and iron oxide  
nanorods to increase the current efficiency of  
MFCs. Due to the large specific surface area of the  
electrode, high electrical conductivity as well as  
large sites for oxygen uptake in this electrode, the  
oxidation-reduction reaction occurs very quickly;  
as far as the power output density of the cell could  
be maintained for more than 600 hours [13]. By  
previous studies, a cathode was made of carbon  
nanotubes doped with titanium oxide nanoparticles  
aimed at enhancing the current output density and  
increasing the elimination of residual chemical  
oxygen demand (COD). The results of this study  
revealed an increase in the specific surface area  
and the active sites for oxygen uptake, so that the  
maximum current output density produced was  
15.16 mW m-2  
and the COD removal efficiency  
was reported between 54-71% (after 10 days),  
which was related to the presence of active reaction  
sites on the electrode [14]. The results showed us,  
the specific surface area is a very effective factor in  
increasing the efficiency of MFCs.  
In this study, the graphite rod as a high stability and  
electrical conductivity was used for wastewater  
treatment. So, the surface modification of graphite  
rod by zeolite nanocatalyst will increase the  
specific surface area of the electrode. On the other  
hand, the modification of graphite rods with zeolite  
nanocatalyst were compared to simple graphite  
rod with the low price and poor efficiency [15,  
16]. Metal nanoparticles can greatly influence the  
oxygen reduction [17-22]. Hence, in this study the  
graphite rod electrodes were modified with iron  
particles (Fe) as a doping agent on ZSM-5 nano-  
zeolite (G-Z/Fe/ ZSM-5) for increasing of MFC  
efficiency for wastewater treatment.  
2. Experimental  
2.1. Material  
The ZSM-5 nanocatalyst powder (from the Zeolites  
family) was purchased from Sigma Aldrich with  
a crystal size of 0.5 μm and a pore size of 5.5A0.  
Ferric chloride (FeCl3), the potassium chloride  
(KCl), the sodium di-hydrogen phosphate dihydrate  
(NaH2PO4.2H2O), di-sodium hydrogen phosphate  
dihydrate (Na2HPO4.2H2O), the ammonium  
chloride (NH4Cl) and sulfuric acid (H2SO4,  
%98) were also purchased from Merck Germany.  
Nafion117 membrane (DuPont, the USA) was used  
to Preparation the cell.  
2.2. Preparation of ZSM-5/Fe Nanocatalyst  
To Preparation the functionalized ZSM-5  
nanocatalyst, first 2.5 g of ZSM-5 nanozeolite  
powder was placed in the furnace at a temperature  
of 500°C for 4 hours and calcined. Then, 0.5 g of  
ferric chloride (FeCl3) powder was dissolved in  
Anal. Method Environ. Chem. J. 4 (1) (2021) 26-35  
28  
Fig.1. Schematic of the preparation process and calcination of ZSM-5/Fe nanocatalyst  
distilled water twice for one hour, added to the  
calcined ZSM-5 nanozeolite powder and mixed  
for another 30 minutes, and filtered with a filter  
paper. The resulting powder was rinsed three times  
with distilled water and placed in an oven at a  
temperature of 80°C for 2 hours. Next, the powder  
was separated from the filter paper and re-calcined  
at a temperature of 500°C for 4 hours. The method  
of preparation above nanocatalyst is schematically  
illustrated in Figure1.  
metal. Brunauer-Emmett-Teller (BET) surface  
area analysis (Belsorb apparatus, Japan) was used  
to determine the SSA of nanocatalyst particles,  
and energy-dispersive X-ray spectroscopy (EDX,  
MIRA III SAMX, Czech Republic) were applied to  
investigate the surface modification of the graphite  
electrode by each of the nanocatalysts.  
2.4. Electrode Modification  
To modify the graphite surface and to impregnate  
with the synthesized nanocatalyst powders, 0.5 g  
of each of the produced nanocatalysts (ZSM-5,  
ZSM-5/Fe) was poured into a test tube and 10 ml  
of ethanol was added and the graphite electrode  
was inserted into the test tube and placed in an  
2.3. Characterization  
X-ray diffraction (XRD, STADI-P, the USA)  
was used to investigate ferrous (Fe) metal in the  
nanocatalyst structure functionalized with these  
Fig. 2. Schematic of electrode surface modification by ZSM-5/Fe nanocatalyst  
Treatment of wastewater by G-Z/Fe electrode in MFCs  
Mostafa Hassani et al  
29  
ultrasonic bath for 20 minutes. Then, the resulting  
electrode was rinsed twice with deionized water  
and placed in a furnace at a temperature of 300°C  
for 2 hours (Fig.2).  
this purpose, in order to maintain the acid strength  
in the cell, 50 mM of phosphate buffered solution  
(PBS) (0.13 g L-1 of potassium chloride, 3.32 g L-1  
of sodium di-hydrogen phosphate dihydrate, 5.13 g  
L-1 of di-sodium hydrogen phosphate dihydrate, and  
0.31 g L-1 of ammonium chloride) was prepared in  
the cathode chamber and 375 mL was poured into  
the cathode chamber [23].  
2.5. MFC construction and operation  
This study applied with a separate two-part cell  
consisting of anaerobic anode and aerobic cathode.  
The chambers were made based on 500 mL pyrex  
glass with 75% of the volume as a working volume  
(375 mL). The two chambers were separated by a  
pyrex tube with an inner diameter of 0.8 cm and a  
length of 13.4 cm embedded in the middle portion  
with the proton exchange Nafion 117 membrane.  
The electrodes were made with rod graphite and  
heated at 3000°C with an area of 22.62 cm2. In order  
to remove any impurities and improve membrane  
performance, the membrane was first boiled  
for an hour in 3% H2O2 and then washed in 1 M  
sulfuric acid for 1 hour. Oxygen gas was injected  
into the cathode with a sparger at a flow rate of 20  
ml min-1, and nitrogen gas was injected into the  
anode chamber to provide anaerobic conditions. A  
magnetic stirrer was used to stir the solutions inside  
the anode and cathode chambers, and a copper  
wire was used to bond the anode and the cathode  
electrodes. Acidification of the medium inhibits  
the optimal growth of the bacteria in the anode  
chamber, so it is necessary to use a buffer with  
appropriate pH in the bacterial growth medium. For  
2.6. Microorganisms  
In the anodic chamber of the fuel cell, the anaerobic  
wastewater prepared from the industrial town  
treatment plant was used as inoculum. The samples  
from the treatment plant were stored in stainless  
steel containers at 4°C, and transferred to the  
laboratory. The combined inoculum was inoculated  
into the pre-prepared culture medium containing  
1 g L-1 of glucose, 3 g L-1 of yeast extract, 11 g  
L-1 of peptone, 0.5 g L-1 of ammonium chloride  
[24]. During the experiments, the cells were kept  
at room temperature and stirred at 50 rpm for 72  
hours (Table 1).  
2.7. Analytical method  
A multimeter (MASTECH MS8360G, China) was  
used to measure the output voltage of the cell. The  
residual COD of the samples was measured with  
COD meter (Model 76133, Aqua Litik, Germany).  
Three-electrode systems including, anode electrode  
Table.1. Anaerobic wastewater profile for anode chamber  
of fabricated fuel cell in the present study  
Parametrs  
T
Scale  
22/81  
7/13  
1159  
2076  
1216  
505  
Unit  
oC  
pH  
----  
SV1  
mg L-1  
mg L-1  
mg L-1  
mg L-1  
mg L-1  
(MPN/100 mL)  
MLSS  
COD  
BODs  
DO  
0.6  
Total Coliform  
9000  
Anal. Method Environ. Chem. J. 4 (1) (2021) 26-35  
30  
(modified electrodes), platinum wire electrode, and  
silver/silver chloride electrode (as the working  
electrode) were used to electrochemically measure  
the made electrodes. Cyclic voltammetry (CV) and  
square wave voltammetry (Sqw) with scanning rate  
of 5mV•s−1 in 50 mM phosphate buffered solution  
(PBS) (Palmsense 3, the Netherlands) were used  
to investigate the electrochemical behaviors of the  
electrodes.  
calibration curve was drawn. It was measured by  
placing the absorbance of the unknown sample in  
the residual COD calibration equation.  
3. Results and Discussion  
3.1. BET characterization  
By comparing the as, BET parameter as in Figure  
3 and the results in Table 2, in each of the four BET  
analysis curves of the nanocatalysts, the highest  
SSA was related to the catalyst functionalized with  
Fe metal (ZSM-5/Fe, which was determined to be  
408.41 m2 g-1).  
Spectrophotometric method was used to examine  
the treated wastewater. Initially, standard  
solutions with concentrations of 100-800 with 3  
ml of digestion solution (containing potassium  
dichromate, sulfuric acid and silver sulfate) and  
7 ml of stock solution (potassium hydrogen  
phethalate) are prepared and placed in an oven at  
150 ° C for 1.5 hours was placed. After cooling, it  
was placed in a spectrophotometer (600nm) and the  
3.2. X-Ray Diffraction (XRD) analysis  
The XRD spectrum for the ZSM-5 and the ZSM-5/  
Fe nanocatalyst was shown in Figure 4. The ZSM-  
5/Fe nanocatalyst confirms the presence of iron  
particles doped with silicate particles (Fig. 4).  
Fig.3. BET curves of prepared nanocatalysts  
Table 2. specific surface area of prepared nanocatalysts  
Row  
Nanocatalysts  
BET  
Unit  
1
2
ZSM-5  
ZSM-5/Fe  
374.66  
408.41  
m2 g-1  
m2 g-1  
Treatment of wastewater by G-Z/Fe electrode in MFCs  
Mostafa Hassani et al  
31  
Fig. 4. X-ray diffraction (XRD) analysis of nanocatalysts, ZSM-5 and ZSM-5/Fe.  
3.3. Energy dispersive X-ray spectroscopy (EDX)  
analysis  
presence of doped iron particles (in 1Kev area  
in the second curve). The presence of alumina  
and silicate peaks in both curves confirms that  
the surface of the electrodes has been covered by  
nanocatalysts.  
The curves of EDX analyzes for the surface of  
G-Z and G-Z/Fe electrodes compared as Figure  
5a and 5b. The EDX analyzes showed the  
a
b
Fig.5. Energy-dispersive X-ray spectroscopy (EDX) analysis  
of the surface modified electrodes (a) G-Z; (b) G-Z/Fe  
Anal. Method Environ. Chem. J. 4 (1) (2021) 26-35  
32  
of 5mV•s−1in 50 mM phosphate-buffered saline  
(PBS) at an ambient temperature and in the potential  
range of 1 to 90 volts were compared. Comparing  
the electrode peaks, the G-Z/Fe electrode peak has  
the highest current (3500 μA cm-2) relative to other  
electrodes. The graphite electrode peak has the  
lowest current (2000 μA cm-2), which indicates that  
the ZSM-5 nanocatalyst doped with iron caused to  
increase the current of analysis.  
3.4. Electrochemical characterization  
Comparing the cyclic voltammetry (CV) cerves for  
G, G-Z and G-Z/Fe was shown in Figure 6a, 6b  
and 6c. The peak of the graphite electrode modified  
with iron-doped nanocatalyst (ZSM-5/Fe), which  
has a higher specific surface area, has the maximum  
current compared to other electrodes. Due to Figure  
7, the square wave (Sqw) voltammetric peaks of the  
G, GZ-5 and GZ-5/Fe electrodes, with the scan rate  
Fig. 6. Cyclic voltammetry (CV) analysis of electrodes prepared in 50 mM phosphate  
buffered solution (PBS) in room temperature. (a)G, (b)G-Z, (c)G-Z/Fe  
Treatment of wastewater by G-Z/Fe electrode in MFCs  
Mostafa Hassani et al  
33  
Fig.7. Square wave voltammetry (Sqw) analysis of electrodes prepared  
in 50 mM phosphate buffered solution (PBS) in room temperature.  
According to Figure 7 and 8, the peak related to  
the output current and removal of COD during 72-  
hour fuel cell steering, it can be concluded that the  
produced G-Z/Fe cathode electrode has a higher  
output efficiency (21/8%) and COD removal  
efficiency (36/9%) than G-Z electrode and simple  
graphite. The electrochemical analyzes (CV and  
Sqw) show higher efficiency of this electrode and  
Figure 9 showed the chemical oxygen demand  
(COD) for graphen, G-Z and G-Z/Fe electrods..  
Fig.8. Cell current output per time for G, GZSM-5 and GZSM-5/Fe  
Fig..9. The efficient removal of COD for G,G-Z and G-Z/Fe electrods  
Anal. Method Environ. Chem. J. 4 (1) (2021) 26-35  
34  
production, Sci. Total Energy Prod., 754  
4. Conclusions  
(2021) 142429.  
Byprocedure, anewmicrobialfuelcellwasmadeby  
graphite rod electrodes. The surface of the cathode  
was modified by ZSM-5 and ZSM-5 functionalized  
with iron nanocatalyst. All three electrodes (G,  
G-ZSM and G-ZSM/Fe) were analyzed by square  
wave and cyclic voltammetry. Both analyses  
were introduced that the G-Z/Fe electrode had the  
higher efficiency as compared to others (Fig. 6-7).  
Experimental results of fuel cell steering was also  
studied as the Figure 8 and 9 by the G, G-Z and G-Z/  
Fe electrode, the results showed that the efficiency  
of fuel cell output current (I) and residual chemical  
oxygen demand (%COD) based on this electrode  
increased up to 21.8% and 36.9%, respectively as  
compared to other graphite electrode. The high  
efficiency of G-ZSM/Fe nanocatalyst electrode is  
due to high specific surface area and the presence  
of iron particles with high electrical conductivity.  
[5] W.W. Li, H.Q. Yu, Z. He, Towards sustainable  
wastewater treatment by using microbial fuel  
cells-centered technologies, Energy Environ.  
Sci., 911 (2014)7-24.  
[6] S.K. Chaudhuri, D.R. Lovley, Electricity  
generation by direct oxidation of glucose  
in mediatorless microbial fuel cells, Nat.  
Biotechnol., 21(2003)1229–1232.  
[7] B. Logan, S. Cheng, V. Watson, G. Estadt,  
Graphite fiber brush anodes for increased  
power production in air-cathode microbial  
fuel cells, Environ. Sci. Tech., 41 (2007)  
3341–3346.  
[8] X. Gao, Y. Zhang, X. Li, J. Ye, Novel graphite  
sheet used as an anodic material for high-  
performance microbial fuel cells, Mat.  
Lett.,105 (2013) 24–27.  
[9] E.Y. Emori, F.H. Hirashima, C.H. Zandonai,  
C.A. Ortiz-Bravo, N.R.C. Fernandes-  
Machado, M.H.N. Olsen-Scaliante, Catalytic  
cracking of soybean oil using ZSM5 zeolite,  
Catal.Today, 279 (2017)168–176.  
5. Acknowledgments  
The authors would like to thank and appreciate  
Mr. Mojtaba Azemi Motlagh, Laboratory  
Technical Manager of Arman Shimi Palayesh  
Gostar Company, as well as Mr. Hoshang Asadi,  
Personnel of Chemistry Laboratory at Islamic Azad  
University, South Tehran Branch, for providing  
laboratory facilities and equipment.  
[10] Q. Zhang, G. Liu, L. Wang, X. Zhang, G. Li,  
Controllable decomposition of methanol for  
active fuel cooling technology, Energey Fuels,  
28 (2014) 4431–4439.  
[11] W. Li, G. Li, C. Jin, X. Liu, J. Wang, One-step  
synthesis of nanorod-aggregated functional  
hierarchical iron-containing MFI zeolite  
microspheres, J. Mater. Chem., A, 3 (2015)  
14786–14793.  
6. References  
[1] B. Min, S. Cheng, B.E. Logan, Electricity  
generation from swine wastewater using  
microbial fuel cells, J. Water Res., 39  
(2005)1675–1686.  
[12] A. Valipour, S. Ayyaru, Y. Ahn, Application  
of graphene-based nanomaterials as novel  
cathode catalysts for improving power  
generation in single chamber microbial fuel  
cells, J. Power Sour., 327 (2016) 548-556.  
[13] G.G. Kumar, C.J. Kirubaharan, D.J. Yoo, A.R.  
Kim,Graphene,poly(ethylenedioxythiophene),  
Fe3O4 nanocomposite: An efficient oxygen  
reduction catalyst for the continuous electricity  
production from wastewater treatment  
microbial fuel cells, Int. J. Hydrogen Energy,  
41 (2016)13208e13219.  
[2] Z. Lu, D. Chang, J. Ma, G. Huang, L.  
Cai, L. Zhang, Behavior of metal ions in  
ioelectrochemical systems:Areview, J. Power  
Sour., 275 (2015) 243–260.  
[3] S.S. Kumar, V. Kumar, Microbial fuel cells  
(MFCs) for bioelectrochemical treatment  
of different wastewater streams, Fuel, 254  
(2019)115526.  
[4] C. Munoz-Cupa, Y. Hu, An overview of  
microbial fuel cell usage in wastewater  
treatment, resource recovery and energy  
Treatment of wastewater by G-Z/Fe electrode in MFCs  
Mostafa Hassani et al  
35  
[14] S.A.A. Yahia. L. Hamadou, M.J. Salar-  
García, A. Kadri, V.M. Ortiz-Martínez, F.J.  
Hernández-Fernández, A. Pérez de los Rios,  
N. Benbrahim, TiO2 nanotubes as alternative  
cathode in microbial fuel cells: Effect  
ofannealing treatment on its performance,  
Appl. Sur. Sci., 387 (2016) 1037–1045.  
hybrids as cathode catalysts in microbial fuel  
cells, J. Power Sour., 307 (2016) 561-568.  
[23] Q. Wena, Y. Wua, D. Cao, L. Zhao, Q.Sun,  
Electricity generation and modeling of  
microbial fuel cell from continuous beer  
brewery wastewater, Bio. Tech.,100 (2009)  
4171-4175.  
[15] S.S. Manickam, U. Karra, L.W. Huang, N.N.  
Bui, B.K. Li, J.R. McCutcheon, Activated  
carbon nanofiber anodes for microbial fuel  
cells, Carbon, 53 (2013) 19–28.  
[24] S. Fatemi, A.A. Ghoreyshi, G.H. Najafpour,  
M. Rahimnejad, Investigation of bioelectricity  
production in dual chamber microbial fuel cell  
by mixed culture as active biocatalyst, Iran. J.  
Biol., 27 (2013) 546-554.  
[16] J. Liu, Y. Qiao, C.X. Guo, S. Lim, H. Song,  
C.M. Li, Graphene/carbon cloth anode for  
high-performance mediatorless microbial fuel  
cells, Bioresour.Technol. Rep., 114 (2012)  
275–280.  
[17] S. Kalathil, S. Patil, D. Pant, Microbial fuel  
cells: electrode materials, encyclopedia of  
interfacial chemistry, Sur. Sci. Electrochem.,  
Elsevier, 309-318, 2018.  
[18] M. Jose Salar-Garcia, O. Obata, H. Kurt  
, K. Chandran, Impact of Inoculum Type  
on the Microbial Community and Power  
Performance of Urine-Fed Microbial Fuel  
Cells, Microorgan., 8 (2020) 1921. http://  
doi:10.3390/microorganisms8121921.  
[19] L.Yang,Y. Tang, D.Yan, T. Liu, C. Liu, S. Luo,  
Polyaniline-reduced graphene oxide hybrid  
nanosheets with nearly vertical orientation  
anchoring Palladium nanoparticles for highly  
active and stable electrocatalysis, ACS Appl.  
Mater. Interfaces, 8 (2016) 169–176.  
[20] P. Pattanayak, F. Papiya, V. Kumar, N.  
Pramanik, P.P. Kundu, Deposition of Ni–NiO  
nanoparticles on the reduced graphene oxide  
filled polypyrrole: Evaluation as cathode  
catalyst in microbial fuel cells, Sustain.  
Energy Fuels, 3 (2019) 1808–1826.  
[21] P. Mishra, R. Jain, Electrochemical deposition  
of MWCNT-MnO2/Ppy nano-composite  
application for microbial fuel cells, Int. J.  
Hydrogen Energy, 41 (2016) 22394-22405.  
[22] Y. Hou, H.Yuan, Z.Wen, S. Cui, X. Guo, Z. He,  
J. Chen, Nitrogen-doped graphene/CoNi alloy  
encased within bamboo-like carbon nanotube  
Anal. Method Environ. Chem. J. 4 (1) (2021) 36-45  
Research Article, Issue 1  
Analytical Methods in Environmental Chemistry Journal  
AMECJ  
Speciation and removal of selenium (IV, VI) from water  
and wastewaters based on dried activated sludge before  
determination by flame atomic absorption spectrometry  
Mahdiyeh Ghazizadeha,, Abdollah Abbaslooa and Farzaneh Bivarb  
a Department of Chemistry, Kerman Branch, Islamic Azad University, Kerman, Iran, P. O. Box 167-7635131  
b Department of Chemical engineering, Sirjan Branch, Islamic Azad University, Kerman, Iran, P.O. Box 187-78185  
A R T I C L E I N F O :  
Received 4 Dec 2020  
A B S T R A C T  
In recent decades, large amount of pollutants enters to the environment  
due to development of technology. Therefore, it is necessary to use  
ecofriendly sorbent to eliminate pollutants. In this research, 0.5 g of  
a dried activated sludge (DAS) was used for speciation selenium and  
removal of selenite [Se(IV)] from water and wastewater samples.  
The effect of operating parameters such as solution pH, the amount  
of bio-sorbent, contact time, temperature and initial concentration  
of selenium were studied by flame atomic absorption spectrometry  
(F-AAS). Kinetic data was adjusted to the Langmuir and Freundlich  
kinetic equations. The resulted showed that the Langmuir equation  
with a correlation coefficient of 0.9825 has the best match to  
tetravalent selenium biosorption on DAS. The FT-IR results showed  
that the biosorption mechanism of Se(IV) on DAS is due to functional  
groups on the DAS surface (Se(IV)…. DAS). For reduction of soluble  
selenate [Se(VI), SeO42−] to selenite [Se(IV), SeO32−], the concentrated  
HCl was used at 70oC (30 min). So, the Se(VI) reduced to Se(IV)  
and total selenium (TSe) was determined and the Se (VI) was simply  
calculated by difference of TSe from Se(IV) content. The method was  
validated based on spiking samples in water and wastewater samples  
by F-AAS and using HG-AAS.  
Revised form 9 Feb 2021  
Accepted 30 Feb 2021  
Available online 30 Mar 2021  
------------------------  
Keywords:  
Selenium,  
Water and wastewater,  
Speciation,  
Activated sludge,  
Biosorption,  
Isotherms.  
glass manufacturing, the agriculture and mining  
1. Introduction  
activities increase the selenium concentration in  
the environment matrixes [6-8]. Selenium is also  
used in thermal power stations, the solar panels,  
insecticides, semiconductors and rectifires [9]. Two  
species of this element exist in aqueous systems  
contain Se(IV) and Se(VI) in the form of selenite  
(SeO32-) and selenite (SeO42-), respectively. Se(IV)  
is more toxic than Se(VI) [2, 10]. World Health  
Organization (WHO) proposed the permissible  
limit of selenium concentration in drinking water  
should be below 10 µg L-1 [11-14]. Therefore,  
removal of selenium from wastewaters by an  
Recently, the selenium studies are considered  
strongly because of the direct correlation between  
biologicalfunctionsandtheamountofseleniuminter  
the body [1, 2]. Selenium is an essential bioelement  
and has an important role in the proper biological  
functioning of many organisms [3, 4], although it  
becomes toxic when the concentration is more than  
1.7 µg L-1 [5]. Modern industrial processes such as  
the oil refining, the electrolytic copper refining, the  
*Corresponding Author: Mahdiyeh Ghazizadeh  
Removal of selenium by dried activated sludge  
Mahdiyeh Ghazizadeh et al  
37  
2.2. Apparatus  
economic and effective methods is necessary. The  
most appropriate methods for removing selenium  
from contaminated water include catalytic  
reduction, chemical precipitation, electrochemical  
process, evaporation, floatation, ion exchange,  
membrane processes, biosorption and adsorption  
[2, 15]. Most of these techniques are expensive  
and improper for removal of selenium from  
aqueous samples. However, biosorption can be an  
effective and ecofriendly method for this purpose.  
Low cost and availability are two major factors  
for using biomass to remove the environmental  
pollutant [15, 16]. Biosorption of selenium by  
several sorbents such as seaweed, crustacean shell,  
peanut shell, rice barn, maize, wheat and dry yeast  
biomass is reported [17-20]. Recently the usage  
of DAS for removing selenium is extended [21,  
22]. In addition, the different instrumental analysis  
was used for determination of selenium and other  
metals in different matrixes [23-27]. In this study,  
the removal of selenium by DAS from aqueous  
solutions were studied by F-AAS and validated  
by HG-AAS. The effect of pH, concentration,  
temperature and contact time was investigated.  
Kinetic models and thermodynamic parameters  
were determined.  
Flame atomic absorption spectrometer (F-AAS,  
Varian spectra 220 model, Australia) with  
wavelength 196.0 nm; slit 1.0 nm; current 10 mA  
was used (10-200 mg L-1). The hydride generation  
atomic absorption spectrometer (HG-AAS, 1-100  
μg L-1) and electro thermal atomic absorption  
spectrometer (ET-AAS, 15- 400 μg L-1) were  
applied as ultra-trace analysis for Se (IV). The  
analytical pH meter (Benchtop meter inoLab pH  
7110 model, WTW company, Germany), analytical  
balance (ALC model, Acculab company, America),  
magnetic hitter stirrer (IKA RH basic 2 model,  
IKA company, Germany), and centrifuge (EBA 20  
model, Hettich company, Germany) were used for  
this study.  
2.3. Preparation of dried activated sludge as a  
biosorbent  
The activated sludge obtained from Zamzam  
company was suspended in a beaker containing 500  
ml of deionized water on a magnetic stirrer for a  
day at 25oC. Let the suspension to precipitate. Then  
the upper liquid was decanted and the remaining  
suspension was centrifuged. The resulted sludge  
was washed with deionized water several times  
to be neutralized. The collected sample was dried  
in oven at 80oC for 36 h. The dried biomass was  
powdered and sieved with mesh No. 25.  
2. Experimental  
2.1. Chemicals  
Sodium selenite (Na2SeO3) with a purity of 98%,  
was purchased from Merck (India) and used as a  
source of Se(IV) ions in the aqueous samples for  
analytical purpose , sodium hydroxide (NaOH)  
with a purity of 98% was purchased from Merck  
(Darmstadt, Germany, http://www.merck.com),  
hydrochloric acid (HCl) with a purity of 37% was  
purchased from Merck (Darmstadt, Germany,  
obtained from Kerman Zamzam refinery, Iran. The  
different concentration of Selenium was prepared  
by dilution of deionized water (DW) and ultrapure  
water was purchased from Millipore Company. The  
acetate and phosphate buffer was used to adjust the  
pH between 2.6–6.4 and 6.4–8.0, respectively.  
2.4. Preparation of sample and selenium  
solutions  
All glass or PCV tubes were cleaned with a  
2M of HNO3 solution for at least one day and  
then washed for ten times with ultrapure water.  
As low concentrations of Se(IV) and Se(VI) in  
water samples, the ion contamination effected on  
results of analysis, so, we used ultra-trace reagents  
for sampling processes. Sodium selenite was  
used to prepare a selenium stock solution with  
concentration of l000 ppm (mg L-1). The desired  
solutions obtained of diluting stock solution. The  
diluted solutions with concentrations in the range  
2-9.5 ppm were used for calibration.  
Anal. Method Environ. Chem. J. 4 (1) (2021) 36-45  
38  
2.5. SPE procedure and Batch experiments  
from Se(IV) content. The linear range(LR), LOD,  
perconcentration factor (PF) and recovery were  
obtained 0.5-10.2 mg L-1, 0.12 mg L-1 and 19.8, and  
96.5%, respectively  
Biosorption of Se(IV) by DAS was achieved in  
optimized experimental conditions such as pH,  
contact time, amount of biosorbent and temperature.  
The experiments were carried out in 100 ml  
Erlenmeyer flasks. Experiments were achieved with  
pH 2 to 9, contact time 2 to 35 minute, amount of  
biosorbent 0.5 to 3 g, temperature 10 to 40oC and  
selenium concentration 10 to 140 mg L-1. To adjust  
required pH of aqueous solution, HCl 0.2 M and  
NaOH 0.1 M were added. Finally, the kinetic models  
and isotherms were studied. The absorption capacity  
of DAS for Se(IV) was obtained 124.2 mg g-1 by 140  
mg L-1 selenium concentration and 1 g of DAS.  
By solid phase extraction procedure (SPE), 0.5 g  
of biosorbent of DAS added to 100 mL of water  
and wastewater solution and shaked for 15 min at  
pH=5. After adsorption, based on chemical bonding  
between DAS with Se(IV) [−NH+:−NH2+----SeO32−]  
the solid phase separated/collected in bottom of  
tube and removed upper liquid phase of water/  
wastewater. Finally, the Se(IV) determined with  
F-AAS after desorption Se(IV) from DAS by adding  
of HNO3 (0.5 M, 5 mL). The concentration Se(IV)  
validated by HG-AAS after dilution with DW. For  
reduction of Se(VI) to Se(IV) the concentrated HCl  
(50%) was used at 70oC for 30 min. After reduction,  
the total selenium (TSe) was determined and the Se  
(VI) was simply calculated by difference of TSe  
3. Results and discussion  
3.1. FT-IR analysis  
Fourier Transform Infrared (FT-IR) spectrum of  
DAS was recorded (Fig. 1) to gain the information  
about surface functional group. As seen in this  
spectrum, the stretching vibrations of hydroxyl  
group (−OH) on DAS surface gives the broad and  
strong band at 3443 cm-1. The weak peaks at about  
2300 cm-1 show the stretching vibrations of –NH,  
−NH+, −NH2+ functional groups of DAS. The band  
peak at 1646 cm-1 refers to stretching vibrations of  
−C═O group. The stretching vibrations of −C−O  
group appears at 1088 cm-1. The band peak at 876  
cm-1 is concerned to carbonate group.  
3.2. Effect of pH  
The effect of pH on the biosorption of Se (IV)  
by DAS were studied at pH in the range of 2 to  
11 for SPE. First, 100 mL selenium solution with  
concentration 2-9.5 ppm (mg L-1) and 0.5 g DAS  
at temperature of 25oC (15 min) was used. The  
results were shown in Figure 2. Three species  
of selenium in these aqueous solutions include  
selenite (SeO32-), biselenite (HSeO3-) and selenious  
Fig.1. Fourier Transform Infrared (FT-IR) spectrum of DAS  
Removal of selenium by dried activated sludge  
Mahdiyeh Ghazizadeh et al  
39  
3.3. Effect of contact time  
acid (H2SeO3) [28, 29]. The selenious acid prevails  
when pH decreases below 3.5, biselenite prevails  
when pH is in the range of 3.5 to 9 [2]. The lowest  
selenium biosorption at pH less than 3.5 is because  
of inability of neutral selenious acid to interact  
electrostatically with the DAS. In this work, the  
highest chemical biosorption of Se(IV) based on  
DAS was achieved with high recovery more than  
95% for batch system and SPE procedure at pH=5.  
The effect of contact time, as the next parameter  
was investigated in the range of 2 to 35 minute at  
pH=5. As observed in Figure 3, the most proper  
contact time for selenium biosorption was obtained  
15 minutes for SPE. After this contact time,  
equilibrium occurred. The best time for batch  
system was obtained 30 min (2 g) for selenium  
concentration 10 to 140 mg L-1.  
Fig.2. The effect of pH on Se(IV) removal from water and wastewater by DAS  
Fig.3. The effect of contact time for removal of Se(IV) from water and wastewater by DAS  
Anal. Method Environ. Chem. J. 4 (1) (2021) 36-45  
40  
3.4. Effect of amount of biosorbent  
optimized amount of DAS. Therefore, a number of  
Se(IV) ions remain in solution and biosorption yield  
decreased. At higher amount of DAS, biosorption  
yield is almost unchanged. Because most of Se(IV)  
ions interact with DAS surface. For SPE, the 0.5 g  
of DAS is favorite mass for removal of Se (IV) in  
water samples with high recovery more than 95%.  
The effect of amount of biosorbent was investigated  
under optimized conditions (pH=5 and contact  
time: 30 min.). As shown in Figure 4, the selenium  
biosorption increased slowly with the DAS amount  
up to 2 g for batch system. The DAS surface  
becomes saturated with the extra Se(IV) ions in  
120  
100  
80  
60  
40  
20  
0
0.2  
0.5  
1
1.5  
2
2.5  
3
3.5  
Amount of DAS( g)  
Fig. 4. The effect of biosorbent amount on Se(IV) removal in batch system (green)  
and SPE procedure(blue) in water and wastewater by DAS  
10  
15  
20  
25  
30  
35  
40  
45  
Temperature (oC)  
Fig. 5. The effect of temperature on Se(IV) removal in batch system (blue) and SPE  
procedure(green)from water and wastewater samples by DAS  
Removal of selenium by dried activated sludge  
Mahdiyeh Ghazizadeh et al  
41  
3.5. Effect of temperature  
3.7. Kenetic isotherms for Se(IV) and Se(VI)  
The effect of temperature on selenium biosorption  
was investigated between 10-45oC in optimized  
condition. The results showed us, the optimum  
temperature was achieved 30oC in optimized  
condition (pH, contact time and amount of  
biosorbent DAS were 5, 30 minute and 2 g,  
respectively). Due to Figure 5, by increasing  
temperature, the selenium biosorption decreased. It  
indicated the biosorption by DAS is an exothermic  
reaction. The best temperature for SPE procedure  
for DAS was 25-30oC.  
The most popular isotherms are Langmuir [21,30]  
and Freundlich [21, 31] models. The Langmuir  
model describes monolayer adsorption, however  
Freundlich model show heterogeneous surface.  
The linear form of Langmuir model is given by  
following equation I:  
(Eq. I)  
where Ce (mg L-1) is the equilibrium concentration of the  
solution, qe (mg g-1) is the amount of metal adsorbed per  
specificamountofadsorbent,qm(mgg-1)isthemaximum  
amount of metal ions required to form monolayer, K (L  
mg-1) is the adsorption equilibrium constant.  
The linear form of Freundlich model is given by  
following equation II:  
3.6. Effect of initial concentration of selenium  
Effect of initial concentration of selenium in the  
rangeof20-250ppmwasinvestigatedforabsorption  
capacity. The results indicated that increasing  
selenium concentration caused to more absorb of  
the selenium on DAS and decreased the selenium  
concentration in the solution. The number of sites  
on DAS were interacted with Se(IV) ions and can  
be saturated at high concentrations of selenium  
ions. According to obtained results, the adsorption  
capacity of Se(IV) ions on DAS increased up to  
124.2 mg g-1 [AC; mg per gram]. The results have  
presented in Figure 6.  
(Eq. II)  
where n is the adsorption intensity and KF is the  
adsorption capacity.  
TheamountofSe(VI)adsorbedonDASatequilibrium  
(qe, mg g-1) was calculated by Equation (III):  
qe= (C0-Ce) × V/m  
(Eq. III)  
140  
120  
100  
80  
60  
40  
20  
0
20  
70  
90  
110  
140  
150  
160  
250  
Conc. Se(mg L-1)  
Fig. 6. The effect of initial concentration of Se(IV) ions on absorption capacity  
of DAS in water and wastewater samples  
Anal. Method Environ. Chem. J. 4 (1) (2021) 36-45  
42  
where C0 and Ce (mg L-1) are the initial and  
equilibrium Se(VI) concentrations, respectively, V  
(L) is the volume of the solution and m (g) is the  
mass of the adsorbent. (C0 = 10-250 mg L-1, C0=250  
mg L-1 and Ce=190 mg L-1, V=0.1 L, m=0.05 g).  
So the qe, qmax and Ce/qe was obtained as 120 mg  
g-1, 120 mg g-1 and 2.08, respectively. As different  
concentrations, the Ce/qe were calculated based on  
Langmuir model between 0.02-2.08.  
isotherm (Fig. 7). The Se(VI) in solutions with  
different initial concentrations (C0 = 10-250 mg  
L-1) were used. Langmuir constants, KL and qm  
were calculated from the slope and intercept of the  
plot Ce/qe versus Ce.  
As Figure 8, the linear Freundlich isotherm of Se(IV)  
and Se(VI) is a another kenetic model for DAS.  
Freundlich isotherm parameters, KF and 1/n were  
calculated from the slope and intercept of linear plot.  
Linear Langmuir equation was considered to gain  
2.5  
2
y = 0.0108x  
R2=0.9825  
1.5  
1
0.5  
0
0
50  
100  
Ce(mg L-1)  
150  
200  
Fig. 7. Linear Langmuir equation for selenium removal by DAS biosorbents  
from water and wastewater samples  
0.2  
0
y = 0.4205x - 0.84  
R² = 0.9547  
-0.2  
-0.4  
-0.6  
-0.8  
-1  
Se (VI)  
y = 0.3827x - 0.9139  
R² = 0.9621  
-1.2  
-0.7  
-0.2  
0.3  
0.8  
1.3  
1.8  
logCe  
Fig. 8. Linear Freundlich isotherm for selenium removal by DAS biosorbents  
from water and wastewater samples  
Removal of selenium by dried activated sludge  
Mahdiyeh Ghazizadeh et al  
43  
3.8. Validation of SPE procedure  
a satisfactorily result for determination of Se(IV)  
and Se(VI) in water samples (Table 1). Moreover,  
the real water samples were analyzed with HG-  
AAS/ET-AAS and used for validation of results  
of SPE/F-AAS procedure. The results showed,  
the favorite efficiency and reliability of proposed  
method for determination selenium in water and  
wastewater sample which was compared to ET-  
AAS and HG-AAS (Table 2)  
The selenium was removed and determined in  
100 mL of water and wastewater samples based  
on DAS with SPE procedure at pH=5. The mean  
concentration of Se(IV) more than Se(VI) in water  
samples. The spiked water was used to demonstrate  
the reliability of the method for determination  
of Se(IV) and Se(VI) in water samples by SPE  
procedure. The recovery of spiked samples showed  
Table 1. Validation of SPE procedure based on DAS for speciation selenium (VI, IV) in water  
and wastewater samples (mg L−1; n=8)  
Added  
Se(IV)  
Added  
Se(VI)  
*Found  
Se(IV)  
*Found  
Se(VI)  
Total  
TSe  
Recovery Recovery  
Se(IV) (%) Se(VI) (%)  
Sample  
Wastewater 1  
-----  
4.0  
-----  
0.5  
4.45± 0.19  
1.23± 0.05 5.68 ± 0.24  
-----  
96.0  
-----  
98.8  
-----  
104  
8.29 ± 0.37 1.75 ± 0.07 10..04± 0.45  
3.86± 0.18 0.56 ± 0.03 4.42 ± 0.22  
Wastewater 2  
Wastewater 3  
River  
-----  
4.0  
-----  
0.5  
-----  
94.7  
-----  
98.6  
-----  
103.5  
7.81 ± 0.35  
1.95 ± 0.14  
3.98 ± 0.19  
ND  
1.03 ± 0.05  
1.47± 0.08  
2.95 ± 0.14  
ND  
8.84 ± 0.42  
3.42 ± 0.15  
6.93 ± 0.34  
ND  
-----  
2.0  
-----  
1.5  
-----  
101.5  
-----  
94.9  
-----  
2.0  
-----  
2.0  
1.97 ± 0.11  
2.07 ± 4.4 4.04 ± 0.21  
*x ± ts /√n at 95% confidence (n=8)  
Well water prepared from Varamin agricultural  
Wastewater 1 prepared from drug company  
Wastewater 2 prepared from petrochemical factory  
Wastewater 3 prepared from paint factory  
River water prepared from Karaj  
Table 2. Comparing of proposed procedure for selenium determination by F-AAS/DAS with HG-AAS and ET-AAS  
Sample  
F-AAS/DAS(mg L−1)  
ET-AAS(μg L-1)*  
*HG-AAS(μg L-1)  
Wastewater*  
Water  
0.55 ± 0.25  
ND  
5.36 ± 0.52  
40.9± 13.81  
ND  
41.3 ± 13.81  
x ± ts /√n at 95% confidence (n=5)  
*Wastewater 1 prepared from drug company, 1 mL of sample diluted with DW up to 100 (1:100)  
Anal. Method Environ. Chem. J. 4 (1) (2021) 36-45  
44  
biosorption of selenium (IV) ions onto  
4. Conclusions  
Ganoderma Lucidum Biomass, Sep. Sci.  
Tech., 48 (2013) 2293-2301.  
In this study, the results showed tetravalent  
selenium ions (Se IV) biosorption were successfully  
achieved by DAS from contaminated aqueous  
solutions. The maximum removal of Se(IV) ions  
was 96% at optimized experimental conditions  
by SPE/F-AAS. The interaction between Se(IV)  
ions and functional groups of DAS surface was  
exothermic. The experimental data were fitted to  
Freundlich isotherm. Also the speciation Se(IV)  
and Se (VI) ions determined based on DAS by SPE  
procedure for 0.5 g of DAS at pH=5. The method  
was validated by ET-AAS and HG-AAS. The  
absorption capacities for Se(IV) and Se (VI) ions  
with DAS were achieved 124.2 mg g-1 and 121.8  
mg g-1, respectively.  
[6] H. Robberecht, R.V. Grieken, Selenium  
in environmental water: determination,  
speciation and concentration levels, Talanta,  
29 (1982) 823-844.  
[7] J. Lessa, A. Araujo, G. Silva, L. Guilherme,  
G. Lopes, Adsorption-desorption reactions  
of selenium (VI) in tropical cultivated and  
uncultivated soils under Cerrado biome,  
Chemosphere, 164 (2016) 271-277.  
[8] S. Santos, G. Ungureanu, R. Boaventura, C.  
Botelho, Selenium contaminated waters: an  
overview of analytical methods, treatment  
options and recent advances in sorption  
methods, Sci. Total Environ., 521-522 (2015)  
246-260.  
5. Acknowledgments  
[9] E.I. El-Shafey, Sorption of Cd(II) and Se(IV)  
from aqueous solution using modified rice  
husk, J. Hazard. Matter., 147 (2007) 546- 555.  
[10] F.Sahin, M. Volkan, A.G. Howard, O.Y.  
Ataman, Selective preconcentration of selenite  
from aqueous samples using mercapto-silica,  
Talanta, 60 (2003) 1003-1009.  
[11] G. Kallis, D. Butler, The EU water framework  
directive: measures and implications, Water  
Policy, 3 (2001) 125- 142.  
The authors would like to thank from Department  
of Chemistry, Kerman Branch, Islamic Azad  
University, Kerman, Iran.  
6. References  
[1] M. Kashiwa, S. Nishimoto, K. Takahashi,  
M. Ike, M. Fujita, Factors affecting soluble  
selenium removal by a selenite reduciing  
bacterium Bacillus sp. SF-1, J. Biosci.  
Bioeng., 89 (2000) 528-533.  
[12] O.Y. Bakather, A. Kayvani fard, Ihsanullah,  
M. Khraisheh, M.S. Nasser, M.A. Atieh,  
Enhanced adsorption of selenium ions from  
aqueous solution using iron oxide impregnated  
carbon nanotubes, Bioinorg. Chem. Appl.,  
2017 (2017) 1-12.  
[2] M. Tuzen, A. Sari, Biosorption of  
selenium from aqueous solution by green  
alga  
(Cladophorahutchinsiae)  
biomass:  
Equilibrium, thermodynamic and kinetic  
studies, Chem. Eng. J., 158 (2010) 200-206.  
[3] M. Rovira, J. Gimienez, M. Martiinez, X.  
Marttinez-Lladio, J. Pablo, V. Martii, L. Duro,  
Sorption of selenium(IV) and selenium(VI)  
onto natural iron oxides: goethite and  
hematite, J. Hazard. Mater., 150 (2008) 279-  
284.  
[13] M. Kieliszek, S. Blazejak, K. Piwowarek, K.  
Brzezicka, Equilibrium modeling of selenium  
binding from aqueous solutions by Candida  
atilis ATCC 9950 yeasts, Biotech., 8 (2018)  
388: doi: 10.1007/s13205-018-1415-8.  
[14] F.A. Bertolino, A.A.J. Torriero, E. Salinas,  
R. Olsina, L.D. Martinez. J. Raba,  
Speciation analysis of selenium in natural  
water using square-wave voltammetry after  
preconcentration on activated carbon, Anal.  
Chim. Acta, 572 (2006) 32-38.  
[4] F.M. Fordyce, selenium deficiency and  
toxicity in the environment, Essentials of  
Medical Geology, Elsevier Academic Press,  
Amsterdam, Holland, pp.373-416, 2005.  
[5] K. Nettem, A.S. Almusallam, Equilibrium,  
kinetic, and themodynamic studies on the  
Removal of selenium by dried activated sludge  
Mahdiyeh Ghazizadeh et al  
45  
[15] S. Dev,A. Khamkhash, T. Ghosh, S.Aggarwal,  
Adsorptive removal of Se(IV) by Citrus peels:  
Effect of adsorbent entrapment in calcium  
and Cu (II) Ions from Aqueous Solutions  
by Cadmium Sulfide Nanoparticles, Int. J.  
Nanosci. Nanotechnol., 13 (2017) 105-117.  
[25] H. Shirkhanloo, A. Khaligh, H.Z. Mousavi,  
A. Rashidi, Graphene oxide-packed micro-  
column solid-phase extraction combined with  
flame atomic absorption spectrometry for  
determination of lead (II) and nickel (II) in  
water samples, Int. J. Environ. Anal. Chem.,  
95 (2015) 16-32.  
alginate beads, ACS Omega, 5 (2020) 17215-  
17222.  
[16] R.H.S.F. Vieira, B. Volesky, Biosorption: a  
solution to pollution, Int. Microbiol., 3 (2000)  
17-24.  
[17] D.A. Roberts, N.A. Paul, S.A. Dworjanyn,  
Y. Hu, M.I. Bird, R. de Nys, Gracilaria waste  
biomass (sampah rumput laut) as a bioresource  
for selenium biosorption, J. Appl. Phycol., 27  
(2015) 611-620.  
[26] M. Arjomandi, H. Shirkhanloo, A review:  
Analytical methods for heavy metals  
determination in environment and human  
samples, Anal. Methods Environ. Chem. J., 2  
(2019) 97-126.  
[18] S.H. Hasan, D. Ranjan, Agro-industerial  
waste: a low-cost option for the biosorptive  
remediation 0f selenium anions, Ind. Eng.  
Chem. Res., 49 (2010) 8927-8934.  
[27] H. Shirkhanloo, S. A. H. Mirzahosseini,  
N. Shirkhanloo, The evaluation and  
determination of heavy metals pollution in  
edible vegetables, water and soil in the south  
of Tehran province by GIS, Arch. Environ.  
Protec., 41 (2015) 64-74.  
[19] S. Beeram, A. Morris, C.J. Hardway, J.C.  
Richert, J. Sneddon, Studies of whole  
crawfish shells for the removal of chromium,  
lead and selenium ions in solution, Instrum.  
Sci. Technol., 40 (2012) 618-639.  
[28] M. Duc, G. Lefevre, M. Fedoroff, Sorption of  
selenite ions on hematite, J. Colloid Interface  
Sci., 298 (2006) 556-563.  
[20] H.  
Khakpour,  
H.  
Younesi,  
M.  
Mohammadhosseini, Two-stage biosorption  
of selenium from aqueous solution using dried  
biomass of the baker’s yeast Saccharomyces  
cerevisiae, J. Environ. Chem. Eng., 2 (2014)  
532-542.  
[29] T. Nishimura, H. Hashimoto, M. Nakayama,  
Removal of selenium(VI) from aqueous  
solution with poly-amine type weakly basic  
ion exchange resin, Sep. Sci. Technol., 42  
(2007) 3155-3167.  
[21] H. Zare, H. Heydarzadeh, M. Rahimnejad,  
A. Tardast, M. Seyfi, S.M. Peyghambarzade,  
Dried activated sludge as an appropriate  
biosorbent for removal of copper (II) ions,  
Arab. J. Chem., 8 (2015) 858-864.  
[30] I. Langmuir, The adsorption of gases on plane  
surfaces of glass, mica and platinum, J. Am.  
Chem. Soc., 40 (1918) 1361–1403.  
[31] H. Freundlich, Adsorption in solution. J. Phys.  
Chem., 57 (1906) 384–410.  
[22] L. Bennamoun, P. Arlabosse, A. Leonard.  
Review on fundamental aspect of application  
of drying process to wastewater sludge,  
Renew. Sust. Energ. Rev., 28 (2013) 29-43.  
[23] H. Shirkhanloo, F. Golbabaei, H. Hassani, F.  
Eftekhar, M.J. Kian, Occupational exposure  
to mercury: air exposure assessment and  
biological monitoring based on dispersive  
ionic liquid-liquid microextraction, Iran. J.  
Public Health, 43 (2014) 793.  
[24] S. Golkhah, H. Zavvar Mousavi, H.  
Shirkhanloo, A. Khaligh, Removal of Pb (II)  
Anal. Method Environ. Chem. J. 4 (1) (2021) 46-57  
Research Article, Issue 1  
Analytical Methods in Environmental Chemistry Journal  
AMECJ  
Simultaneous adsorption of cationic and anionic dyes using a  
novel multifunctional mesoporous silica  
Amir Vahid a,*, Majid Abdouss b, Shahnaz Nayeri b, Aliakbar Miran Beigi a  
a Research institute of petroleum industry, Tehran, Iran  
b Faculty of chemistry, Amirkabir University of Technology, Tehran, Iran  
A R T I C L E I N F O :  
Received 17 Nov 2020  
Revised form 22 Jan 2021  
Accepted 15 Feb 2021  
A B S T R A C T  
In the present work a multifunctional nanoadsorbent was synthesized  
via a well-designed stepwise route, led to the grafting of an amine  
group on the interior and acidic sites on the exterior of bimodal  
mesoporous silica nanoparticles (UVM-7). First, amine and thiol  
groups were grafted on the interior and exterior pores of silica  
through co-condensation and post synthesis treatment, respectively.  
Then, the oxidation of thiol on UVM-7 caused to create sulfonic  
acid and the subsequent template extraction was carried out to obtain  
the NH2/UVM-7/SO3H. The results of XRD, the nitrogen sorption,  
SEM, TEM, FT-IR and elemental analysis revealed the presence  
of both types of functional groups on UVM-7. Then, simultaneous  
adsorption of anionic and cationic dyes (Methylene Blue [MB] and  
Direct Red 23 [Dr]) using NH2/UVM-7/SO3H was investigated. UV-  
Vis spectrophotometry was utilized for the determination of dyes in  
single and binary solutions. Langmuir and Freundlich models were  
used for the fitting of obtained experimental adsorption data and the  
constants of both isotherms were calculated for MB and Dr. Morover,  
the calculation of thermodynamic parameters revealed that the  
adsorption of MB and Dr on NH2/UVM-7/SO3H was endothermic  
and spontaneous. Furthermore, the simultaneous adsorption of both  
dyes regardless of their different electrostatic charge is the main  
characteristics of NH2/UVM-7/SO3H which was specially used for  
treatment of industrial wastewater.  
Available online 29 Mar 2021  
------------------------  
Keywords:  
Adsorption,  
Multi-Functional,  
Dye,  
Mesoporous silica,  
Synthesis.  
Methylene Blue (MB) and Direct red (Dr) as the  
1. Introduction  
cationic and anionic dyes have harmful effects on  
human life and environment. Acute exposure to  
MB causes many health effect such as increased  
heart rate and cyanosis jaundice quadriplegia in  
mammals [2,3]. Up to now, the dye adsorption  
studies have focused on solutions containing single  
dye and mixture of dyes [4-6]. The most industrial  
effluents include a mixture of several dyes, so it  
is necessary to study the simultaneous adsorption  
of two or more dyes from aqueous solutions [7,8].  
However, the dyes are resistance to biodegradation  
due to their aromatic structure [9]. Many industrial  
Dyes as a important raw material were used in  
different industries including cloth, plastics,  
tanning, cosmetics and food [1]. Additionally, the  
dyes are one of the most problematic groups as a  
results of their environmental impact. Furthermore,  
the industrial effluents containing dyes may be  
have a carcinogenic effect in humans when,  
discharge to waters without any proper treatment.  
*Corresponding Author: Amir Vahid  
Email: avahid753@gmail.com & vahida@ripi.ir  
Adsorption of dyes by multifunctional mesoporous silica  
Amir Vahid et al  
47  
technologies, including chemical oxidation [10],  
adsorption [11], the coagulation/flocculation [12],  
the membrane separation and ion exchange [13]  
was used for the adsorption of dyes from industrial  
effluents. Among them, adsorption has been  
known as one of the practical physical processes  
for the treatment and cleaning of wastewaters,  
because it is cost effective and very effective. The  
main problem of this technology is the synthesis of  
low cost adsorbent possesses with high adsorption  
capacity [14]. In multi-dye adsorption, the  
interference of one dye on the other dyes is very  
important [15]. The liquid chromatography [16],  
the capillary electrophoresis [17], the spectrometry  
[18] and the electrochemistry methods [19] are  
used for the analysis of dyes. Due to advantages  
of UV–Vis spectrophotometry such as accuracy  
of results, sensitivity, low cost, easy operation  
and reproducibility, it was used for analysis of  
colored samples [20]. The main drawback of this  
technique is the overlap and interference of broad  
absorption peaks. So, the simultaneous analysis of  
mixture dyes could be carried out using derivative  
spectrophotometry [21]. It was determined based  
on the derivative values of interest compound  
while other components have zero value [22].  
Also, many applications were used by UVM-  
7 in different sciences [23-26]. In this work, the  
synthesis of a multifunctional mesoporous silica  
contains both acidic and basic functional groups  
were reported. At the second step, the adsorption  
of MB / Dr from aqueous solution was carried out  
simultaneously and the adsorption phenomenon  
was studied.  
2. Experimental  
2.1. Reagents and materials  
All reagents with ultra-trace analytical grade such  
as; lead nitrate salt, acids and base solutions were  
purchased from Merck (Darmstadt, Germany). The  
structure of MB and Dr are shown in Figure 1.  
Ultrapure water has been obtained from Millipore  
continental water system (Bedford, USA).  
Tetraethyl orthosilicate (TEOS, (CHO)Si,  
CAS N: 78-10-4, Sigma), triethanolamine  
(TEAH3, CH₁₅NO, CAS N: 102-71-6, Sigma),  
cetyltrimethylammonium  
bromide  
(CTAB,  
C₁₉H₄₂BrN, CAS N: 57-09-0, Merck) and other  
reagents with analytical grade were prepared from  
Merck or Sigma Aldrich, Darmstadt, Germany.  
The pH adjustments were made using appropriate  
buffer solutions (Merck, Germany).  
Fig.1. The structure of MB(a) and Dr(b)  
Anal. Method Environ. Chem. J. 4 (1) (2021) 46-57  
48  
2.2. Synthesis of UVM-7  
spectrophotometer at 502 and 664 nm for Dr and  
MB, respectively. In binary solution, the best  
wavelength for each dye was find out utilizing first-  
order derivative spectrometry.  
UVM-7wassynthesizedviawell-knownatraneroute  
in which triethanol amine (TEAH3), has effect on  
the rate of hydrolysis and condensation of teraethyl  
orthosilicate (TEOS). In a typical synthesis, mixture  
of TEOS and TEAH3 heated up to 120 °C and then  
CTAB (cetyltrimethylammonium bromide) was  
added when the temperature of the solution reached  
to 70°C. After addition of water a suspension was  
formed and aged for 4 hours at ambient temperature.  
The final molar composition of the synthesis mixture  
was 1.0 TEOS : 3.5 TEAH3 : 0.25 CTAB : 90 H2O.  
The product was filtered, washed with water and  
acetone and dried in an oven at 80°C overnight and  
calcined at 550°C for 6 hours.  
The adsorption percentage (R%) and adsorption  
capacity of each dye qe, (mg dye/g adsorbent) was  
calculated according to the following equations  
(Eq.1 and Eq.2):  
(
V
C0 Ce)  
=
q
e
M
(Eq. 1)  
(
C0 Ce)  
R% =  
×100  
C0  
2.3. Synthesis of NH2- /UVM-7/SO3H  
(Eq. 2)  
First, 1.0 g of aminopropyle triethoxysilane  
(APTES) was added to the aqueous solution of  
CTAB and after 5 minutes, mixture of TEOS and  
TEAOH, was added to the micellar solution. The  
reactants molar ratio was 1.0 TEOS: 3.5 TEAH3  
: 0.25 CTAB : 90 H2O: 0.20 APTES. After aging,  
the white suspension was filtered and washed  
thoroughly with water and acetone. The white  
precipitate dried in oven over night at 80 °C. At the  
second step, 1.0 g of the as-synthesized NH2/UVM-  
7 and 1.0 g of triethoxysilane propanethiol (TPTES)  
was refluxed in 50 mL of toluene for 12 hours and  
then, the mixture filtered and dried in oven again.  
Then, thiol groups grafted on the external surface  
of the sample was oxidized in 15% H2O2 and 1  
molar solution of H2SO4. Then, CTAB of the as-  
synthesized NH2/UVM-7/SO3H was removed by  
reflux in 1 molar ethanolic solution of HCL for 24  
hours to get access to the internal pores and amine  
groups. The final product was dried in oven at 80  
°C in vacuum oven overnight.  
Where C0 and Ce (mg L-1) are the initial and  
equilibrium concentration of dye, respectively. V  
(L) is the volume of the solution and M (g) is the  
mass of adsorbent used.  
2.5. Characterization  
X-ray diffraction (XRD) patterns were recorded  
using a Philips 1840 diffractometer using nickel-  
filtered Cu Kα (1.5418˚ A) X-ray source, operating  
at 35.4 kV and 28 mA. Textural properties of the  
synthesized samples were measured by nitrogen  
adsorption at 77 K using a BELSORP-max  
apparatus after being out-gassed in vacuum at 120  
°C. ElementalanalysiswascarriedoutusingCHNS-  
Elementar. FT-IR spectra was recorded using a FT-  
IR 70 VERTX Bruker spectrophotometer using  
KBr powder. UV–Vis spectrophotometer was used  
to measure the concentration of the Methylene  
Blue and Direct red23 in aqueous solution. FE-  
SEM images were captured using Mira TESCAN  
3-XMU. Samples were sputtered with gold prior  
to imaging. TEM images were recorded at 150 kV  
operating voltage using a Zeiss microscope.  
2.4. Batch adsorption procedure  
In each test, 0.1 g of adsorbent was added to the 10  
mL of a solution containing a known concentration  
of each dyes while agitating at 250 rpm at 25 °C.  
After 120 minutes the concentration of residual  
dyes in supernatant was determined by UV–Vis  
3. Results and discussion  
3.1. Characterization of NH2/UVM-7/SO3H  
XRD pattern of NH2/UVM-7/SO3H is shown in Figure 2.  
Adsorption of dyes by multifunctional mesoporous silica  
Amir Vahid et al  
49  
A strong and broad diffraction peak can be observed  
which is characterized in bimodal meso/macroporous  
material. This peak can be attributed to diffraction of  
incident X ray from the d100 plane. According to the  
hexagonal symmetry, two weak and broad peaks at  
higher diffraction angles can be assigned to d110 and  
overlap of d200 and d210 planes, respectively.  
pressure, the inflection is not sharp. By approaching  
to the saturated relative pressure, increasing of gas  
uptake led to the sharp increasing of isotherm. This  
can be attributed to the inter particles of UVM type  
material which is also present in NH2/UVM-7/  
SO3H after internal and external grafting of organic  
moieties. The high BET surface area and pore  
volume means that the pore structure/size almost  
preserved after grafting. However, after grafting  
of organic moieties on UVM-7, the sharpness of  
these region slightly decreases. The two inflections  
in NH2/UVM-7/SO3H can be attributed to the  
presence of two types of pore system.  
3.2. Nitrogen physisorption  
The isotherms of UVM-7 and NH2/UVM-7/SO3H  
is shown in Figure 3. The isotherms showed the  
four type of isotherm according to the IUPAC  
classification. In both isotherms, at low relative  
Fig. 2. The XRD pattern of NH2/UVM-7/SO3H  
Fig. 3. The isotherms of UVM-7 and NH2/UVM-7/SO3H  
Anal. Method Environ. Chem. J. 4 (1) (2021) 46-57  
50  
Fig.4. The SEM of NH2/UVM-7/SO3H  
Fig.5. The TEM of NH2/UVM-7/SO3H  
3.3. TEM and SEM  
FT-IR spectra of SO3H/UVM-7/NH2 is shown in  
Figure 6. FT-IR spectroscopy was utilized to indicate  
the existence of NH2 and SO3H functional groups  
on the UVM-7. Two distinct peaks around 457 cm-1  
and 1082 cm-1 is attributed to the symmetric and  
asymmetric stretching bands of Si-O-Si group in the  
framework of UVM-7. A broad peak at around 3451  
cm-1 is assign to the silanol groups on the surface  
of UVM-7. A small absorption band at 1558 cm-1 is  
attributed to the bending vibration of amine group  
which overlapped with symmetric bending vibrations  
of O-H. A stretching mode of NH2 is also overlapped  
with silanol group’s around 3451 cm-1. This indicates  
that the UVM-7 possess of NH2 groups. A shoulder,  
overlapped with asymmetric stretching of Si-O-Si,  
Electron microscopy is a powerful technique  
provides a direct view of porous structure, particle  
morphology and many other information of  
porous materials at nanoscale. The SEM of NH2/  
UVM-7/SO3H reveals the particle size, shape and  
morphology of nanomaterials. Figure 4 illustrates  
the SEM image of NH2/UVM-7/SO3H. The sample  
composed of nanosize particles without presence of  
large agglomerates. The shape of the nanoparticles is  
almost irregular. The TEM image of the NH2/UVM-  
7/SO3H is taken perpendicular to d100 direction of  
pores and is displayed in Figure 5. Pore openings are  
clearly visible. Particle size in sub-ten nanometers  
and is in agreement with those seen in SEM image.  
Fig. 6. The FT-IR spectra of SO3H/UVM-7/NH2  
Adsorption of dyes by multifunctional mesoporous silica  
Amir Vahid et al  
51  
is attributed to the SO3- and S=O stretching mode  
of sulfonic acid functional group. It cannot be seen  
absorption mode of S-H group in the entire spectrum  
means that thiol groups were fully oxidized to  
sulfonic acid. Two small absorption peaks at 2852  
cm-1 and 2926 cm-1 is characteristic of the stretching  
vibration mode of methylene groups of the propyl  
chain of the APTES and TPTES.  
These results proof presence of amine and sulfonic  
acid functional groups on NH2/UVM-7/SO3H.  
3.4. Determination of MB and Dr in single and  
binary solution  
The calibration curve obtained from absorbance  
spectra of MB and Dr versus concentration at λmax of  
the corresponding dye and used for the determination  
of dyes in single solution. The concentration of dyes  
in binary solution of MB and Dr is obtained by first  
order derivative spectrophotometry by plotting the  
change rate of absorbance against wavelength. The  
obtained spectra for raw and derivative spectra are  
displayed in Figure 7a and 7b.  
These results approve coexistence of amine and  
sulfonic acid groups on UVM-7 simultaneously.  
This statement is supported by elemental analysis  
of NH2/UVM-7/SO3H. Elemental analysis of NH2/  
UVM-7/SO3H revealed that the sample contains  
4.9% (w/w basis) of nitrogen and 5.0% of sulfur.  
Fig. 7a. The Raw absorption spectra of: MB (20 mg L-1), Dr (15 mg L-1),  
and their mixture at λmax of the corresponding dye  
Fig. 7b. The first derivative spectra of MB, Dr, and their mixture  
by plotting the change rate of absorbance against wavelength  
Anal. Method Environ. Chem. J. 4 (1) (2021) 46-57  
52  
The calibration curves for determination of each  
dye in the presence of the other one were obtained  
by measuring of first-order derivative at the zero  
crossing points of Dr (502 nm) and MB (664nm)  
[27, 28]. Several standard binary mixtures of MB  
and Dr were used for the validation of the method.  
The regression equations and coefficients of  
determinations, are given in Table 1.  
isotherm was higher than that of Freundlich, which  
implies that suggestions of Langmuir model. The  
homogenous adsorption sites, equal activation  
energy and monolayer formation, is predominantly  
determine the mechanism of adsorption. The  
isotherm constants are presented in Table 2.  
(Eq. 3)  
(Eq. 4)  
3.5. Equilibrium modeling  
3.5.1.Single-component adsorption isotherm  
Two well-known adsorption model, Langmuir and  
Freundlich, were applied to the adsorption data of  
single-component dye solution (Equation 3 and  
4) [29, 30]. In single solution, the R2 of Langmuir  
3.5.2. Multi-component adsorption isotherms  
In this case, competition for occupation of  
adsorption sites by adsorbate molecules occur and  
Table 1. Determination of MB and Dr in mixture solution using zero-derivative  
and first-derivative spectrophotometry  
Solution No.  
*MB(mg L-1)  
*Dr (mg L-1)  
a Regression equations  
R2  
1
2
1-5  
0
S = 0.008C+0.1841  
B = 0.0015C+0.002  
S = 0.0471C+0.021  
B = 0.0001C-0.0006  
0.9981  
0.9890  
2-20  
10  
3
0
1-10  
0.9974  
0.9963  
4
2
10-25  
*C is the concentration of the corresponding dye(mg L-1)  
aS and B is the response in single and binary solution  
Table 2. Parameters of Langmuir and Freundlich models in single and binary solutions.  
Langmuir  
MB(sin)  
qe(mg g-1)  
52.63  
b(mg L-1)  
0.226  
0.0983  
0.0096  
0.1315  
n
R2  
0.987  
0.996  
0.876  
0.977  
Dr(sin)  
88.33  
MB(bin)  
18.86  
Dr(bin)  
100  
Frendlich  
MB(sin)  
Kf(mg g-1)  
0.0272  
3.412  
3.984  
2.32  
0.947  
0.950  
0.958  
0.806  
Dr(sin)  
23.28  
MB(bin)  
98.24  
Dr(bin)  
172.60  
5.29  
Extended-Langmuir  
MB(bin)  
qmax (mg g-1)  
74.32  
b1  
b2  
R2  
0.0021  
0.0043  
0.0038  
0.0056  
0.999  
0.998  
Dr(bin)  
106.78  
Condition: 10 mL solution, pH: 4 in single and binary solutions.  
Adsorption of dyes by multifunctional mesoporous silica  
Amir Vahid et al  
53  
led to a complex adsorption model. Furthermore,  
for the design of treatment/refining systems,  
understanding the mechanism of multi-component  
adsorption is very important. Despite the difficulty  
of obtaining of a model for adsorption of binary  
widely used to explain kinetic of adsorption. The  
model was described by the following Equation 6:  
1
1
1
= k1  
(Eq. 6)  
q q ( ) + q  
t
t
e
e
mixtures,  
extended-Langmuir  
model  
was  
developed to explain equilibrium adsorption model  
Where qe and qt are the adsorption capacities (mg g-1)  
at equilibrium and at time t, respectively. K1 is the rate  
constant of pseudo-first order adsorption (L min-1).  
The pseudo-second order rate equation of McKay and  
Ho can be represented in the Equation 7.  
in such system is as Equation 5:  
q
i bi ci  
=
×100  
q
(Eq. 5)  
e.i  
1+ bj cj  
Using non-linear regression technique, parameters  
of Equation 5 were obtained given in Table 2. High  
regression coefficients (R2: 96.98–99.86) indicate  
that the extended Langmuir model has the ability  
to explain the adsorption equilibrium of binary  
solution of MB and Dr.  
t
1
1
(Eq. 7)  
=
t
q
+ q  
q2  
k2  
t
e
e
Where qe is the equilibrium adsorption capacity,  
and K2 is the pseudo-second order constants  
(g mg-1.min-1). These terms can be determined  
experimentally from the slope and intercept of plot  
t/qt versus t, shown in Figure 8. The coefficients  
of both models are shown in Table 3. In all cases  
including single and binary solutions, the pseudo-  
second order model has better coefficient of  
determination, R2, which means that kinetic of  
adsorption od MB and Dr on NH2 /UVM-7/SO3H  
can be explained by The difference between two  
kinetic model can be attributed to the number and  
accessibility of adsorption sites, specific surface  
area, pore size, nature of the functional groups of  
adsorbent and chemical structure of dyes.  
3.6. Adsorption kinetic  
The kinetic data of adsorption was obtained with  
the initial concentrations of 50 mg L-1 and 100 mg  
L-1 for MB and Dr, respectively. Solutions prepare  
in 25 mL flask with the stirring rate of 300 rpm and  
the contact time was changed in the range of 10  
to 120 minutes. to evaluate if there are changes/  
interferences in the adsorption process in the  
presence of other dyes in the solution.  
3.6.1. Pseudo-first order model  
The pseudo- first order kinetic model has been  
Table 3. Kinetics parameters values for the adsorption of MB and Dr on NH2-SO3H/UVM-7  
in single (sin) and binary (bin) dyes solution  
Pseudo-first order  
qe(mg g-1) K1(min) R2  
Pseudo-second order  
qe(mg g-1) K2(g mg-1.min-1)  
R2  
MB(sin)  
Dr(sin)  
40  
3.7  
2.43  
2.142  
1
0.867  
0.765  
0.876  
0.765  
50  
0.0012  
0.372  
0.962  
0.983  
0.934  
0.826  
4.3  
5.26  
12.98  
90.9  
MB(bin)  
Dr(bin)  
15.87  
66.66  
0.082  
0.00068  
Anal. Method Environ. Chem. J. 4 (1) (2021) 46-57  
54  
Fig. 8. The effect of pretreatment pH on selective adsorption of MB (a)  
and Dr (b) on NH2-SO3H/UVM-7 in binary solution (temperature 30◦C, 400 mgL-1 initial dye concentration).  
3.6.2. Selective adsorption of cationic and  
anionic dyes  
is temperature in Kelvin. The apparent equilibrium  
constant (Kc) of the adsorption is defined as  
Equation 9.  
Figure 8 displays that NH2/UVM-7/SO3H can  
selectively adsorb the anionic Dr from the Dr/MB  
mixture and pretreated at pH=5. While, the NH2/  
UVM-7/SO3H can selectively adsorb the cationic  
MB dye from the Dr/MB mixture and pretreated at  
pH=10. This test verifies with the easy, the special  
treatment and selective adsorption of cationic or  
anionic dyes by NH2-SO3H/UVM-7.  
ca  
= cb  
(Eq. 9)  
kc  
Where Ca and Cb is the equilibrium concentration  
(mg L-1) a of corresponding dye on the adsorbent  
and in the solution, respectively. The Kc value is  
used in the Equation 10 to determine the Gibbs free  
energy of adsorption (ΔG).  
3.6.3. Thermodynamic studies  
The effect of temperature on the adsorption  
of MB and Dr onto NH2/UVM-7/SO3H was  
investigated. The obtained results indicate that  
the amount of equilibrium adsorption (qe) of  
MB and Dr on the NH2/UVM-7/SO3H slightly  
increases with increasing temperature which  
reveals the endothermic nature of adsorption. Main  
thermodynamic parameters including standard free  
energy (ΔG), enthalpy (ΔH) and entropy (ΔS) were  
obtained using Equation 8.  
(Eq. 10)  
Furthermore, ΔH and ΔS were calculated from the  
slope and intercept of the linear plot of lnKc versus  
1/T, respectively. The obtained thermodynamic  
parametersaresummarizedinTable4.AllΔGvalues  
are negative which imply that the spontaneous  
nature of adsorption. Furthermore, the value of  
ΔG becomes more negative with increasing of  
temperature, indicating that the adsorption process  
is more favorable at higher temperature. As can be  
seen in Table 4, the positive value of adsorption  
enthalpy, ΔS, confirms the endothermic nature the  
adsorption process.  
(Eq. 8)  
Where R is gas constant (8.314 Jmol-1K-1) and T  
Adsorption of dyes by multifunctional mesoporous silica  
Amir Vahid et al  
55  
Table 4. Values of thermodynamic parameters for dye adsorption  
from binary solution onto NH2/UVM-7/SO3H  
Dye  
Temp.(K)  
ΔG(kJ mol-1)  
ΔH(kJ mol-1)  
ΔS(kJ mol-1 k-1)  
298  
-2.95  
8.1  
0.038  
308  
318  
328  
298  
308  
318  
328  
-3.21  
-3.43  
-3.98  
-4.83  
-5.82  
-6.98  
-7.83  
MB  
26.3  
0.106  
Dr  
4. Conclusions  
6. References  
InThis work, a novel synthesis method was developed  
for the preparation of an adsorbent contains both  
sulfonic acid and basic amine groups in the exterior  
and interior pores of UVM-7, respectively. This  
multifunctional adsorbent, NH2/UVM-7/SO3H, can  
be used for simultaneous removal of multiple dyes  
with different electrostatic charge. In real aqueous  
sample and wastewater there are several dyes which  
differ in their nature. Furthermore, one of the most  
effective parameters in the removal of dye is its  
electrostatic charge. On the other hand, large pore size  
and surface area of UVM-7 can improve the diffusion  
of the dye toward the adsorption sites. This improved  
diffusion rate can be accompanied by small size of the  
adsorbent particles, UVM-7, to improve adsorption  
yield. However, it would be very useful in terms of  
industrial point of view, to have a single adsorbent to  
remove a variety of pollutants. The proposed method  
can be applied to use a variety of adsorbents and open  
us a way for treatment of wastewaters which normally  
contain many types of pollutants.  
[1] F. I. Vacchi, A. F. Albuquerque, J. A.  
Vendemiatti, D. A. Morales, A. B. Ormond,  
H. S. Freeman, G. J. Zocolo, M. V. B. Zanoni,  
G. Umbuzeiro, Chlorine disinfection of dye  
wastewater: Implications for a commercial  
azo dye mixture, Sci. Total Environ., 442  
(2013) 302–309.  
[2] M.Anbia, S.A. Hariri, Removal of methylene  
blue from aqueous solution using nanoporous  
SBA-3, Desalination, 261 (2010) 61–66.  
[3] M. T. Yagub, T. K. Sen, S. Afroze, H. M. Ang,  
Dye and its removal from aqueous solution by  
adsorption: a review, Adv. Colloid Interface  
Sci., 209 (2014) 172–184.  
[4] H. Chaudhuri, S. Dash, A. Sarkar, SBA-15  
functionalised with high loading of amino  
or carboxylate groups as selective adsorbent  
for enhanced removal of toxic dyes from  
aqueous solution, New J. Chem., 40 (2016)  
3622-3634.  
[5]` Z. Wu, Q. Lu, W. H. Fu, S. Wang, C. Liu,  
N. Xu, D. Wang, Y. M. Wang, Z. Chen,  
Fabrication of mesoporous Al-SBA-15 as a  
methylene blue capturer via a spontaneous  
infiltration route, New J. Chem., 39 (2015)  
985-993.  
5. Acknowledgments  
The authors would like to thank from Faculty of  
chemistry, Amirkabir University of Technology,  
Tehran, Iran.  
Anal. Method Environ. Chem. J. 4 (1) (2021) 46-57  
56  
[6] B. Coasne, Multiscale adsorption and  
[15] M. Turabik, Adsorption of basic dyes from  
single and binary component systems onto  
bentonite: Simultaneous analysis of Basic  
Red 46 and Basic Yellow 28 by first order  
derivative spectrophotometric analysis  
method, J. Hazard. Mater., 158 (2008) 52–  
64.  
transport in hierarchical porous materials,  
New J. Chem., 40 (2016) 4078-4094.  
[7]J. F. Gao, J. H. Wang, C. Yang, S. Y. Wang,  
Y. Z. Peng, Binary biosorption of Acid Red  
14 and Reactive Red 15 onto acid treated  
okara: Simultaneous spectrophotometric  
determination of two dyes using partial least  
squares regression, Chem. Eng. J., 71 (2011)  
967–975.  
[16] M. Kucharska, J. Grabka, A review of  
chromatographic methods for determination  
of synthetic food dyes, Talanta, 80 (2010)  
1045–1051.  
[8] J. F. Gao, Q. Zhang, K. Su, J. H. Wang,  
Competitive biosorption of Yellow 2G  
and Reactive Brilliant Red K-2G onto  
inactive aerobic granules: simultaneous  
determination of two dyes by first-order  
derivative spectrophotometry and isotherm  
studies, Bioresour. Technol., 101 (2010)  
5793–5801.  
[17] A. A. Peláez-Cid, S. Blasco-Sancho, F.  
M. Matysik, Determination of textile  
dyes by means of non-aqueous capillary  
electrophoresis  
with  
electrochemical  
detection, Talanta, 75 (2008) 1362–1368.  
[18]C. Bosch Ojeda, F. Sanchez Rojas, Recent  
applications in derivative ultraviolet/visible  
absorption spectrophotometry: 2009–2011:  
A review, Microchem. J., 106 (2013) 1–16.  
[19] F. Sánchez Rojas, C. Bosch Ojeda, Recent  
development in derivative ultraviolet/visible  
absorption spectrophotometry: 2004-2008: a  
review, Anal. Chim. Acta, 635 (2009) 22–44.  
[20] C. Bosch Ojeda, F. Sanchez Rojas, Recent  
developments in derivative ultraviolet/  
visible absorption spectrophotometry, Anal.  
Chim. Acta, 518 (2004) 1–24.  
[9] V. K. Gupta, B. Gupta,A. Rastogi, S.Agarwal,  
A. Nayak, A comparative investigation on  
adsorption performances of mesoporous  
activated carbon prepared from waste rubber  
tire and activated carbon for a hazardous azo  
dye--Acid Blue 113, J. Hazard. Mater., 186  
(2011) 891–901.  
[10] P. K. Malik, S. K. Saha, Oxidation of direct  
dyes with hydrogen peroxide using ferrous  
ion as catalyst, Sep. Purif. Technol., 31  
(2003) 241–250.  
[21] J.  
Zolgharnein,  
M.  
Bagtash,  
T.  
[11] M. Anbia, S. A. Hariri, S. N. Ashrafizadeh,  
Adsorptive removal of anionic dyes by  
modified nanoporous silica SBA3, Appl.  
Surf. Sci., 256 (2010) 3228–3233.  
Shariatmanesh, Simultaneous removal  
of binary mixture of Brilliant Green  
and Crystal Violet using derivative  
spectrophotometric  
determination,  
[12] S. Wang, H. Li, L. Xu, Application of  
zeolite MCM-22 for basic dye removal from  
wastewater, J. Colloid Interface Sci., 295  
(2006) 71–78.  
multivariate optimization and adsorption  
characterization of dyes on surfactant  
modified nano-γ-alumina, Spectrochim.  
Acta - Part A Mol. Biomol. Spectrosc., 137  
(2015) 1016–1028.  
[13] G. Ciardelli, L. Corsi, M. Marcucci,  
Membrane Separation for Wastewater Reuse  
in the Textile Industry, Resour. Conserv.  
Recycl., 31 (2001) 189–197  
[22] A. Vargas and M. Reyes, Integral solutions  
to complex problems: climate change,  
adaptation policies and payment for  
ecosystem services schemes, Int. J. Plur.  
Econ. Educ., 3 (2012) 173.  
[14] N. Suzuki, J. Liu,Y.Yamauchi, Recent progress  
on the tailored synthesis of various mesoporous  
fibers toward practical applications, New J.  
Chem., 38 (2014) 3330-3335.  
[23] H. Shirkhanloo, A. Khaligh, F. Golbabaei,  
Z. Sadeghi, A .Vahid, A. Rashidi, On-line  
Adsorption of dyes by multifunctional mesoporous silica  
Amir Vahid et al  
57  
micro column preconcentration system  
based on amino bimodal mesoporous silica  
nanoparticles as a novel adsorbent for  
removal and speciation of chromium (III,  
VI) in environmental samples, J. Environ.  
Health Sci. Eng. 13 (2015) 1-12.  
performance, kinetics and thermodynamics,  
Water, 12(2020)981. doi:10.3390/w12040981  
[24] H. Shirkhanloo, S.D. Ahranjani, A lead  
analysis based on amine functionalized  
bimodal mesoporous silica nanoparticles  
in human biological samples by ultrasound  
assisted-ionic liquid trap-micro solid phase  
extraction, Journal of pharm. Biomed.  
Anal.,157 (2018) 1-9.  
[25] H. Shirkhanloo, M. Falahnejad, H.Z.  
Mousavi, On-line ultrasound-assisted  
dispersive micro-solid-phase extraction  
based on amino bimodal mesoporous silica  
nanoparticles for the preconcentration  
and determination of cadmium in human  
biological samples, Biol. Trace Elem.  
Res., 171 (2016) 472-481.  
[26] H. Shirkhanloo, M. Falahnejad, H.Z.  
Mousavi, Mesoporous silica nanoparticles  
as an adsorbent for preconcentration and  
determination of trace amount of nickel in  
environmental samples by atom trap flame  
atomic absorption spectrometry, J. Appl.  
Spec., 82 (2016) 1072-1077.  
[27] C.P. Ye, R. N. Wang, X. Gao, W.Y. Li, CO2  
Capture  
Performance  
of  
supported  
phosphonium dual amine-functionalized  
ionic liquids@MCM-41, Energy Fuels, 34 (2020)  
14379-14387.  
[28] A. Balcha, P.O. Yadav, T. Dey,  
Photocatalytic degradation of methylene  
blue dye by zinc oxide nanoparticles  
obtained from precipitation and sol-gel  
methods, Environ. Sci. Pollut. Res. Int.,  
23 (2016) 25485–25493.  
[29] I. Langmuir, THE adsorption of gases on  
plane surfaces of glass, mica and platinum,  
J. Am. Chem. Soc., 40 (1918) 1361–1403.  
[30] J.Yu,A.Zou,W.He,B.Liu,Adsorptionofmixed  
dye system with cetyltrimethylammonium  
bromidemodifiedsepiolite:characterization,  
Anal. Method Environ. Chem. J. 4 (1) (2021) 58-67  
Research Article, Issue 1  
Analytical Methods in Environmental Chemistry Journal  
AMECJ  
Removal of organic dye compounds in water and wastewater  
samples based on covalent organic frameworks -titanium  
dioxide before analysis by UV-VIS spectroscopy  
Aida Bahadoria and Mehdi Ranjbarb,*  
a Student Research Committee, Kerman University of Medical Sciences, Kerman, Iran  
bPharmaceutics Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran  
A R T I C L E I N F O :  
Received 24 Nov 2020  
Revised form 5 Feb 2021  
Accepted 25 Feb 2021  
A B S T R A C T  
A simple and rapid microwave-assisted combustion method was  
developed to synthesize homogenous carbon nanostructures (HCNS).  
This research presents a new and novel nanocomposite structures  
for removal of methylene red (2-(4- Dimethylaminophenylazo)  
Available online 30 Mar 2021  
------------------------  
benzoic  
phenylazo]benzenesulfonic acid sodium salt) and methylene  
blue (3,7-bis(Dimethylamino)phenazathionium chloride)with  
acid),  
methylene  
orange  
(4-[4-(Dimethylamino)  
Keywords:  
semi degradation-adsorption solid phase extraction (SDA-SPE)  
procedure before determination by UV-VIS spectroscopy. A covalent  
organic frameworks (COFs) with high purity were synthesized and  
characterized by X-ray diffraction (XRD) and scanning electron  
microscopy (SEM). The results indicated that the self-assembled  
carbon nanostructures (COFs) synthesized with the cost-effective  
method which was used as a novel adsorbent for adsorption of dyes  
after semi-degradation of methylene red, orange and blue (1-5 mg  
L-1) as an organic dye by titanium dioxide (TiO2) nanoparticales  
in presence of UV radiation. Based on results, the COFs/TiO2 has  
good agreement with the Langmuir adsorption isotherm model with  
favorite coefficient of determination (R2= 0.9989). The recovery of  
dye removal based on semi-degradation/adsorption of COFs/TiO2 and  
adsorption of COFs were obtained 98.7% and 48.3%, respectively  
(RSD less than 5%). The method was validated by spiking dye to real  
samples.  
Carbon nanostructures,  
Carbon organic frameworks,  
Dye removal,  
Semi degradation-adsorption solid  
phase extraction,  
Titanium dioxide,  
UV radiation.  
importance of the conventional heating methods  
1. Introduction  
(CHM) is due to the microwaves interact with  
the reactants at the molecular level. By CHM, the  
electromagnetic energy is transferred and converted  
to heat by rapid kinetics through the motion of  
the molecules [1-3]. Today, the conservation of  
water resources has been increasingly considered  
by various international organizations such as  
WHO, FDA and EPA. By increasing of population  
growth as a result of over-exploitation of limited  
water resources and on the other hand, water  
pollution due to various biological, agricultural  
Nanomaterials are particles that are in the size  
range between 1-100 nm. The importance of  
nanomaterials in terms of strength is the presence  
of active sites and their low density. Nanomaterials  
have a wide range of applications in optical  
data storage, sensors, light and durable building  
materials, and wastewater treatment. The gained  
*Corresponding Author: Mehdi Ranjbar  
Removal of dye organic compounds by COFs  
Aida Bahadori  
59  
and industrial activities caused to water crisis  
in future years. Methylene organic compounds  
such as methyl red, methyl orange and methyl  
blue are the photoactive phenothiazine dyes [4-  
6]. Paints are one of the main and most important  
pollutants that are used in various industries to dye  
related products. Therefore, a significant amount  
of pollution caused by pigments is produced due  
to their extensive release into the effluent. The  
presence of these dyes in water is inappropriate even  
at very low concentrations and causes widespread  
environmental pollution by pharmaceutical  
industries[7]. Recently, many methods based on  
nanostructure materials was used for removal  
organic compounds. Hence, a simple and rapid  
microwave assisted combustion technique was  
used for synthesis of CdO nanospheres for removal  
pollution in waters [6]. Microwave assisted reverse  
microemulsion process as an easy, low cost and fast  
method can be used for synthesis of nano emulsions  
[8]. Photocatalytic degradation of compounds  
using nanoparticles with ultraviolet light is one of  
the advanced oxidation methods that is expanding  
in recent decades [9, 10]. Photocatalyst as a  
catalyst activated in the presence of light is which  
absorbs light to produce a chemical reaction in the  
environment [11, 12]. When the UV rays reach to a  
surface covered with a photocatalyst the electron-  
cavity can react with molecules on the surface of the  
particles[13]. Bio photocatalytic materials[14] as a  
kind of photocatalyst was used in water purification  
based on degradation and adsorption process[15],  
during the adsorption process, solute molecules  
are removed from the solution and adsorbed by the  
adsorbent. Most of the molecules are adsorbed on  
the surface of the adsorbent pores and small extent  
on the outer surface of the particles. The adsorption  
transfer from the solution to the adsorbent continues  
until the concentration of the solvent remaining in  
the solution is in equilibrium with the concentration  
of the solvent adsorbed by the adsorbent. When  
equilibrium is established, the adsorption transfer  
stops. Adsorption equilibrium is established in the  
dynamic sense when the rate of adsorption of the  
adsorbed component on the surface is equal to its  
rate of absorption [16], self-cleaning glasses and  
organic molecules degradation[17]. Hydrothermal  
synthesis method has many advantage such as  
energy storage[18], simplicity[19], low cost[20],  
better  
nuclear  
control[21],  
pollution-free  
(because reaction takes place indoors)[22], better  
diffusivity[23], high reaction speed and better shape  
control[24]. In recent years, many nanocomposites  
used for degradation or adsorption of organic  
dyes[25-27]. The unique structure of the non-ionic  
surfactant which their unique structure enables them  
to encapsulate water-soluble and water-repellent  
materials [28, 29] and organic building constituent  
units[30]. One of the new techniques in removing  
emerging pollutants is the use of environmentally  
friendly modifiers and reducing the bioavailability  
of pollutants in the environment[31]. In recent  
years, bio-charcoal has been gradually approbated  
which as black gold can be used to solve the  
problem of sustainable development of agriculture  
and other aspects by the academic community[32],  
[33], [34], [35]. In this study, the COFs synthesized  
and used as a novel adsorbent for removal dyes  
based on SDA-SPE procedure in water samples  
after semi-degradation of organic dye by titanium  
) nanoparticales in presence of UV  
dioxide (TiO2  
radiation. The recovery and absorption capacity  
of dyes with COFs/TiO2 were calculated before  
determined by UV-VIS spectrometer.  
2. Experimental  
2.1. Instrumental  
VarianUV-VISspectrophotometerwasusedforthis  
study (Cary 50, USA). UV-VIS spectrophotometer  
included dual beam, the monochromator, the  
wavelength ranges between 190–1100 nm, the  
spectral bandwidth (1.5 nm), the dual Si diode  
detectors, the quartz over coated optics based  
on scan rates of 24000 nm min-1  
and computer  
operating system. The Power Consumption of UV-  
VIS spectrophotometer has supply of 100 - 240  
volts AC and frequency 50 - 60 Hz. The condition  
of UV-VIS spectrophotometers was shown in  
Table 1. The unique optical design enables to  
measure dye samples, also, the large or odd-shaped  
Anal. Method Environ. Chem. J. 4 (1) (2021) 58-67  
60  
Table 1. The condition of UV-VIS spectrophotometers  
Parameters  
Dimensions  
Height  
Values  
477 mm x 567 mm x 196 mm  
196 mm  
Light Source  
Xenon flash lamp (80 Hz)  
Maximum Scanning Speed  
Photometric System  
24,000 nm min-1  
Double beam  
1.5 nm  
Spectral Bandwidth  
samples to be measured. The highly focused beam  
also provides superior coupling to fiber optics  
caused to use the UV-Vis in different matrixes.  
Powder X-ray diffraction (XRD) was prepared by  
a PRO X-ray diffractometer. Scanning electron  
microscopy images were obtained using gun design  
using a point-source cathode of tungsten (SEM,  
Philips XL 30 FEG). The transmission electron  
microscope was used for preparation particle size  
of COFs (TEM, Philips EM 300).  
adjusted by favorite buffer solutions (Merck,  
Germany). The various buffer solutions, the  
acetate (PH=3.0–6.0), the NaH2PO4 / Na2HPO4  
(pH=6.0–8.0) and NH3/NH4Cl (pH=8.0-10) were  
prepared. After adjusted pH samples, the ultra-  
sonication (Grant, U.K) and the centrifuging  
(3000-10000 rpm, 3K30 model) was used for  
extraction and separation nanoparticles from water  
samples(Sigma, Germany).  
2.3. Synthesis of COFs  
2.2. Materials and Reagents  
Covalent organic frameworks (COFs) has two/  
three dimensional structures(2D,3D) which was  
generated by reactions between organic precursors.  
The covalent bonds depended on porous and  
crystalline form. The COFs is an improvements  
of organic material based on coordination  
chemistry. We synthesis COFs was done based  
on the Yaghi method and COFs framework  
scaffolds were prepared by the boronate linkages  
using solvothermal synthetic methods [36-37].  
In fact, the synthesis of COFs was obtained  
by condensation reactions of C6H4[B(OH)2]2  
with C18H6(OH)6 and finally the carbon structure  
of C9H4BO2 (COF5) produced. Moreover, the two  
nozzles electrospinning was used to fabricate the  
scaffolds. The electrospinning experimental setup  
was a nano model (Tehran, Iran) with two nozzles.  
The voltage applied at the tip of the needle was  
18 kV. The mass flow rates were 0.5 ml h-1, and  
distance between the tip of the needle and the  
collector was maintained at 15 cm. The speed of  
the rotary collector was 400 rpm and scanning  
distance was 10 cm. Experimental conditions  
for the preparation of self-assembled carbon  
nanostructures was shown in Table 2.  
Reagents were acquired from Sigma Aldrich  
and Merck companies, Germany. Methanol  
(HPLC grade), toluene, acetone, hexane and  
dichloromethane (HPLC grade) were obtained  
from Merck Ltd. (Germany). More materials used  
in this study such as methyl red [(CH3)2NC6H4N-  
NC6H4CO2H,  
(2-(4-Dimethylaminophenylazo)  
benzoic acid, CAS N: 493-52-7], methyl  
orange [C14H14N3NaO3S, 4-[4-(Dimethylamino)  
phenylazo]benzenesulfonic acid sodium salt, CAS  
N:547-58-0] and methyl blue [C37H27N3Na2O9S3,  
3,7-bis-Dimethylamino)phenazathionium chloride,  
CAS N:28983-56-4) were purchased from Sigma  
company(Germany), C3H7NO (DMF) was  
purchased from Merck company in Germany,  
without further purification. Benzene-1,4-  
diboronic acid (95.0 %, CAS N: 4612-26-4 )  
and  
hexahydroxytriphenylene (C18H6(OH)6,  
CAS N: 4877-80-9, MW 324.3 g moL-1 ) were  
purchased Sigma-Aldrich. The B3O3 (boroxine,  
CAS N: 823-96-1)) was prepared From  
Sigma(Germany). The pH of the water sand  
wastewater samples were digitally calculated by  
pH meter of Metrohm (744, Swiss). The pH was  
Removal of dye organic compounds by COFs  
Aida Bahadori et al  
61  
Table2. Experimental conditions of self-assembled carbon nanostructures.  
DMF: H2O  
( D.R* )  
Time  
(min)  
Temp.  
(C)  
Sample  
Morphology  
1
2
3
4
2:1  
2:1  
2:1  
2:1  
4
8
8
8
180  
180  
200  
200  
NPs**+ Agglomerate  
NPs+ Agglomerate  
NPs+ Agglomerate  
NPs+ Agglomerate  
*Dilution Ratio, **Nanoparticles  
2.4. Removal procedure  
on the Debay-Scherer equation, the particle size of  
COFs nanocomposites was obtained approximately  
50-100 nm. Figure 1 shows the X-ray diffraction  
analysis (XRD) of self-assembled carbon  
nanostructures in different conditions. The results  
show that by increasing of temperature based  
on solvothermal method from 180◦C to 220◦C,  
the crystallized amount of synthesized carbon  
nanostructures (COFs) gradually increases. The  
sharper peaks without any noisy peaks was seen.  
Interestingly, the position (2θ) of the peaks have  
not changed, and only the intensity of the peaks  
increased, which indicates an increase in the degree  
of purity in products.  
For each experiment, a dye solution with a  
concentration of 5 mg per 1000 mL (5 mg L-1) was  
prepared and 0.5 g of COFs as catalyst was added  
to it in presence of TIO2/UV. Then the pH of the  
solution was adjusted with buffer solution between  
3-9 and irradiated with UV radiation. Then, the all  
samples, was stirred with a magnetic stirrer for 15  
min. By SDA-SPE procedure, the amount of dye  
(5 mg L-1) removed by COFs/TIO2/UV. First, the  
dye semi-degradation was obtained in presence of  
TIO2 /UV and intermediate forms of dyes created  
in water samples. The dye and intermediate dye  
were absorbed on COFs with high recovery up to  
98.7%. The nanoparticles of adsorbent separated  
from water solution by centrifuging. Then the  
dye concentration in remained solution was  
directly determined by UV-VIS spectrometry.  
To prevent the reaction of hydroxyl radicals in  
the sample, some ethanol was added to the test  
tubes. Validation of methodology was obtained  
by spiking of real samples by proposed procedure.  
The recovery of proposed method based on COFs/  
TiO2 was achieved for dyes extraction by the below  
equation. The CI is the primary concentrations of  
dye in sample and CF is the final concentration of  
dye by SDA-SPE procedure coupled to UV-VIS  
(n=5, Eq. 1).  
3.2. Measurement size (DLS)  
By increasing of temperature for COFs  
nanocomposites with solvothermal method, the  
sintering process and crystallization of COFs  
was increased and caused to smaller size of nano  
structures. DLS analysis was displayed in Figure 2.  
3.3. Morphological and pore characteristics  
Microscopic morphology and particle-size  
distribution (PSD) of the products were visualized  
by scanning electron microscopy (SEM) images.  
The Figures 3 displays the SEM images of carbon  
nanostructures of COFs. The morphology of COFs  
nanocomposites under the influence of biochar  
concentration change into rods with quantum  
particles-like on its surface. Results show which  
biochar concentration has a great impact on particle  
size of final products.  
Recovery (R%) = (CI-CF)/CI×100  
(EQ.1)  
3. Results and Discussion  
3.1. Structural Analysis  
By full width of the half maximum (FWHM) based  
Anal. Method Environ. Chem. J. 4 (1) (2021) 58-67  
62  
Fig. 1. X-ray diffraction analysis of synthesized self-assembled carbon nanostructures  
Fig. 2. The DLS diagram related to carbon nanostructures of COFs  
Fig. 3. SEM images of carbon nanostructures of COFs  
Removal of dye organic compounds by COFs  
Aida Bahadori et al  
63  
3.4. Photocatalytic semi-degradation/adsorption  
and mechanism  
transfered to the surface of the TiO2 and react with  
O2, H2O, or OH groups and generated radicals. The  
decomposition of Dyes was initiated by the attack  
of •OH on the methyl group of the benzene ring  
of dye, leading to make a new compound. On the  
other hand, the presence of COFs can enhance  
the adsorption ability of the Dye via π-π stacking  
interaction between the π-electrons of the benzene  
rings in dye molecules and π-electron rich region of  
COFs nanostructure.  
The Figure 4 demonstrate the photocatalytic semi-  
degradation of methylene red, methylene blue and  
methylene orange organic dyes using COFs/TiO2  
modified with biochar in time cycles (0 min-40  
min). The results show that the percent degradation  
/adsorption of MO is more than 99 % which can  
be depended on the low steric hindrance of MO  
structure. Also amount the percent degradation/  
adsorption of MR is a little more than MB which  
can also be related to low steric hindrance of MR  
structure ratio to MB. By reducing of time contact  
of photocatalyst with organic dyes, the extraction  
recovery of dyes decreased up to 40-54 % by SDA-  
SPE procedure. TiO2 a highly efficient photocatalyst  
has a small band gap energy and relatively positive  
valance band edge under UV-light irradiation. TiO2  
causedtophotogeneratedelectron-holepairsandthe  
transfer of the charge carriers. The charge carriers  
The effect of pH on the photocatalytic degradation/  
adsorption of MB, MR and MO organic dyes  
were revealed in Figure 5. As results the pH  
don’t effected on extraction dyes on COFs/TiO2  
based on UV radiation by SDA-SPE procedure.  
By procedure, π-π stacking interaction between  
the π-electrons of the benzene rings in dye  
molecules and π-electron rich region of COFs  
nanostructure caused to efficient adsorption after  
semi degradation process.  
Fig. 4. The effect of time on recovery of adsorption/ photocatalytic degradation  
of methylene red, methylene blue and methylene orange organic dyes (0 min-40 min)  
Anal. Method Environ. Chem. J. 4 (1) (2021) 58-67  
64  
Fig. 5. The effect of pH on the photocatalytic semi-degradation/adsorption  
of MB(blue), MR(green dark) and MO(green) organic dyes  
By increasing of time contact of carbon  
nanostructures(COFs) with organic dyes for all  
three dye structures, the degradation/adsorption of  
dyes initially increased due to high surface aria of  
carbon nanostructures of COFs for photoreaction.  
adsorption process on the surface of nanosorbents.  
Large amounts of adsorption rate constants in  
both models can indicate rapid adsorption of dye  
molecules. After desorption, the nanosorbent can  
be used for several cycles (23 N).  
3.5. Kinetic study  
3.6. Validation of method  
Adsorbents in nano sizes of COFs have been shown  
to have better adsorption performance compared to  
other materials due to their high specific surface  
area, small size, and lack of internal penetration  
resistance. The most widespread models of surface  
adsorption isotherms for discontinuous systems  
are the Langmuir and Freundlich models. By the  
proposed procedure the R2 for COFs/TiO2 was  
achieved about 0.9988 and 0.9575 for the Langmuir  
and Freundlich models. So, the Langmuir model  
selected and used for this work. Most nanosorbents  
follow the Langmuir adsorption isotherm model,  
which can be evidence of the homogeneity of their  
surfaces and the fragmentation of the adsorption  
process. Quasi-first-order and quasi-second-order  
synthetic models were well used to describe the dye  
The validation of SDA-SPE method based on  
COFs and COFs/TiO2 in present of UV irradiation  
is important to evaluate the correct statistical  
results for extraction dye from waters. In SDA-SPE  
method, 5 mg L-1 of dyes was made and used for  
extraction dyes from water samples and validated  
by spiking of standard solution to real samples  
(Table 3).  
4. Conclusions  
In this study, COFs and COFs-TiO2 as a novel  
sorbent based on UV radiation was used for dye  
removal/extraction from water samples by SDA-  
SPE procedure. Based on results, the applied, fast,  
sensitive method based on COFs/TiO2/UV was  
demonstrated. The semi degradation/adsorption  
Removal of dye organic compounds by COFs  
Aida Bahadori et al  
65  
Table 3. Validation dye extraction based on COFs/TiO2 and COFs by spiking of real samples  
Conc.  
COFs  
Conc.  
COFs/TiO2  
Recovery (%)  
COFs/TiO2  
Sample  
Added  
Dye  
Recovery (%) COFs  
Wastewater  
-----  
1.5  
MO  
MO  
MR  
MR  
MB  
MB  
1.12 ± 0.07  
2.59 ± 0.13  
2.64 ± 0.12  
5.11 ± 0.23  
0.95 ± 0.04  
1.96 ± 0.12  
1.86 ± 0.11  
3.39 ± 0.17  
3.83 ± 0.19  
6.26 ± 0.27  
1.74 ± 0.08  
2.70 ± 0.14  
-----  
0.98  
-----  
-----  
102  
Wastewater  
Wastewater  
-----  
2.5  
-----  
97.2  
-----  
0.96  
98.8  
-----  
-----  
1.0  
101.2  
of dyes based on COFs/TiO2/UV had efficient  
extraction in the optimized conditions. According  
to the evidence of morphological and COFs  
characterization such as, XRD, SEM and DLs, the  
dyes were efficiently removed from water samples.  
The results showed us, the activity and reaction  
of COFs/TiO2/UV were more than COFs, primary  
carbon structure and TiO2 in optimized conditions.  
Therefore, the fast, simple and efficient method  
based on SDA-SPE was used for removal of dye  
from waters by nanotechnology.  
using supported FeO onto nanoparticles of  
Iranian clinoptilolite, Desalin. Wat. Treat., 35  
(2016) 16483-16494.  
[4] K. Ordon, Functionalized semiconducting  
oxides based on bismuth vanadate with  
anchored organic dye molecules for  
photoactive applications, Le Mans, 2018.  
[5] I.A. Packiavathy, Antibiofilm and quorum  
sensing inhibitory potential of Cuminum  
cyminum and its secondary metabolite methyl  
eugenol against Gram negative bacterial  
pathogens, Int. Food Res. J., 1 (2012) 85-92.  
[6] R. Saravanan, Visible light degradation of  
textile effluent using novel catalyst ZnO/γ-  
Mn2O3, J. Taiwan Ind. Chem. Eng., 45 (2014)  
1910-1917.  
5. Acknowledgments  
Authors are grateful to council of Chemistry and  
Pharmaceutical Sciences and Cosmetic Products  
Research Center, Kerman University of Medical  
Sciences, Kerman, Iran with grant number  
98000651.  
[7] J. Xu, Magnetic properties and methylene  
blue adsorptive performance of CoFe2O4/  
activated carbon nanocomposites, Mater.  
Chem. Phys., 147 (2014) 915-919.  
6. References  
[1] S.A. Khayyat, Photocatalytic oxidation of  
phenolic pollutants and hydrophobic organic  
compounds in industrial wastewater using  
modified nonosize titanium silicate-1 thin  
film technology, J. Nanosci. Nanotechnol.,  
14 (2014) 7345-7350.  
[8] Y. Xu, Holey graphene frameworks for  
highly efficient capacitive energy storage,  
Nat. communications, 5 (2014) 1-8.  
[9] G. Matafonova, V. Batoev, Recent advances  
in application of UV light-emitting diodes for  
degrading organic pollutants in water through  
advanced oxidation processes: A review,  
Water Res., 132 (2018) 177-189.  
[2] C.D. Raman, S. Kanmani, Textile dye  
degradation using nano zero valent iron: a  
review, J. Environ. Manage., 177 (2016) 341-  
355.  
[10] M.Borges, Photocatalysis with solar energy:  
Sunlight-responsive photocatalyst based  
on TiO2 loaded on a natural material for  
wastewater treatment, Solar Energy, 135  
(2016) 527-535.  
[3] Z.A.Mirian,A.Nezamzadeh-Ejhieh,Removal  
of phenol content of an industrial wastewater  
via a heterogeneousphotodegradationprocess  
Anal. Method Environ. Chem. J. 4 (1) (2021) 58-67  
66  
[11] M. Pelaez, A review on the visible light  
active titanium dioxide photocatalysts for  
environmental applications, Appl. Cat. B:  
Environ., 125 (2012)331-349.  
[22] X. Xu, Hydrothermal synthesis of cobalt  
particles with hierarchy structure and  
physicochemical properties, Mater. Res.  
Bull., 72 (2015) 7-12.  
[12] T.P. Yoon, M.A. Ischay, J. Du, Visible light  
photocatalysis as a greener approach to  
photochemical synthesis, Nat. Chem., 2  
(2010) 52-57.  
[23] J. Chen, S. Wang, M.S. Whittingham,  
Hydrothermal synthesis of cathode materials,  
J. Power Sour., 174 (2007) 442-448.  
[24] X.Li, J. Zang, Facile hydrothermal synthesis  
of sodium tantalate (NaTaO3) nanocubes  
and high photocatalytic properties. J. Phys.  
Chem. C, 45 (2009) 19411-19418.  
[13] X.  
Yu,  
Controllable  
preparation,  
characterization and performance of Cu2O  
thin film and photocatalytic degradation  
of methylene blue using response surface  
methodology, Mater. Res. Bull., 64 (2015)  
410-417.  
[25] S. Farhadi, F. Siadatnasab, A. Khataee,  
Ultrasound-assisted degradation of organic  
dyes over magnetic CoFe2O4@ ZnS core-  
shell nanocomposite, Ultrasonics Sonochem.,  
37 (2017) 298-309.  
[14] J. Cao, In situ preparation of novel p–n  
junction photocatalyst BiOI/(BiO) 2CO3 with  
enhanced visible light photocatalytic activity,  
J. Hazard. Mater., 239 (2012) 316-324.  
[15] H. Aziz, Biomaterials supported with titania  
as photocatalyst in peat water purification, J.  
Chem. Pharm., 7 (2015) 192-197.  
[26] M.  
synthesis of YbVO4 nanostructure and  
YbVO4/CuWO4 nanocomposites for  
Eghbali-Arani,  
Ultrasound-assisted  
enhanced photocatalytic degradation of  
organic dyes under visible light, Ultrasonics  
Sonochem., 43 (2018) 120-135.  
[16] P.A.F. Rodrigues, M.J. Geraldes, N.J.  
Belino. Legionella: Bioactive nano-filters  
for air purification systems. in 1st portuguese  
biomedical engineering meeting, IEEE, 2011.  
[17] T. Choi, J. S. Kim, J.H. Kim, Transparent  
nitrogen doped TiO2/WO3 composite films  
for self-cleaning glass applications with  
improved photodegradation activity, Adv.  
Powder Technol., 27 (2016) 347-353.  
[27] E. Costa, P.P. Zamora, A.J. Zarbin, Novel  
TiO2/C  
nanocomposites:  
synthesis,  
characterization, and application as  
a
photocatalyst for the degradation of organic  
pollutants, J. Colloid Interface Sci., 368  
(2012) 121-127.  
[28] J. Zhu, Two-dimensional porous polymers:  
from sandwich-like structure to layered  
skeleton, Accounts Chem. Res., 51 (2018)  
3191-3202.  
[18] H. Hayashi, Y. Hakuta, Hydrothermal synthesis  
of metal oxide nanoparticles in supercritical  
water, Mater., 3 (2010) 3794-3817.  
[29] Y.Song,Anovelascorbicacidelectrochemical  
sensor based on spherical MOF-5 arrayed on  
a three-dimensional porous carbon electrode,  
Anal. Methods, 8 (2016) 2290-2296.  
[19] J.Wen, High-temperature-mixinghydrothermal  
synthesis of ZnO nanocrystals with wide  
growth window, Curr, Appl, Phys,, 14 (2014)  
359-365.  
[30] H. Furukawa, The chemistry and applications  
of metal-organic frameworks, Sci., 341  
(2013) 123-146.  
[20] C.-Y.Cao, Low-cost synthesis of flowerlike  
α-Fe2O3 nanostructures for heavy metal ion  
removal: adsorption property and mechanism,  
Langmuir, 28 (2012) 4573-4579.  
[31] A.U. Czaja, N. Trukhan, U. Müller, Industrial  
applications of metal–organic frameworks,  
Chem. Soc. Rev., 38 (2009) 1284-1293.  
[21] H. Wan, Hydrothermal synthesis of cobalt  
sulfide nanotubes: The size control and its  
application in supercapacitors, J. Power  
Sour., 243 (2013) 396-402.  
[32] M. Larsson,  
Bio-methane upgrading of  
pyrolysis gas from charcoal production, Sustain.  
Energy Technol. Assess., 3 (2013) 66-73.  
Removal of dye organic compounds by COFs  
Aida Bahadori et al  
67  
[33] B. Shen, Elemental mercury removal by the  
modified bio-char from medicinal residues,  
Chem. Eng. J., 272 (2015) 28-37.  
[34] Y.S. Ok, SMART biochar technology:  
a shifting paradigm towards advanced  
materials and healthcare research, Environ.  
Technol. Innov., 4 (2015) 206-209.  
[35] J. Lehmann, J. Gaunt, M. Rondon, Bio-char  
sequestration in terrestrial ecosystems–a  
review, Mitig. Adapt. Strateg. Glob.  
Chang., 11 (2006) 403-427.  
[36] O.M.  
Yaghi, Reticular  
Chemistry:  
Construction, properties, and precision  
reactions of frameworks, J. Am. Chem.  
Soc., 138 (2016) 15507–15509.  
[37] O.M. Yaghi, M. O-Keeffe, N.W. Ockwig,  
H.K. Chae, M. Eddaoudi, J. Kim, Reticular  
synthesis and the design of new materials,  
Nat., 423 (2003) 705-714.  
Anal. Method Environ. Chem. J. 4 (1) (2021) 68-78  
Research Article, Issue 1  
Analytical Methods in Environmental Chemistry Journal  
AMECJ  
Benzene extraction in environmental samples based on the  
mixture of nanoactivated carbon and ionic liquid coated  
on fused silica fiber before determination by headspace  
solid-phase microextraction-gas chromatography  
Afsaneh Afzalia,*, Hossein Vahidib and Saeed Fakhraiec  
a Department of Environment, Faculty of Natural Resources and Earth Sciences, University of Kashan, Kashan, Iran  
b Department of Environment, Institute of Science and High Technology and Environmental Sciences, Graduate University of  
Advanced Technology, Kerman, Iran  
c Chemistry Department, Yasouj University, P.O. Box 7483-75918, Yasouj, Iran  
A R T I C L E I N F O :  
Received 2 Nov 2020  
Revised form 8 Jan 2021  
Accepted 11 Feb 2021  
A B S T R A C T  
In this study, the mixture of nano activated carbon (NAC) and ionic  
liquid (3-triphenylphosphonio-propane-1-sulfonate; C21H21O3PS)  
was coated on fused silica fiber of SPME holder (NAC-IL-FSF/  
SPME). Then NAC/IL was used for determining of benzene in  
soil and vegetables samples (1.0 g, n=50) surrounding a chemical  
industry zone. After benzene adsorption on NAC-IL based on head  
space solid phase micoextraction (HS-SPME), the concentration of  
benzene was simply determined by introducing probe to injector  
of gas chromatography with flame-ionization detection (GC-FID).  
All effected parameters such as the sorbent mass, the amount of  
sample, the temperature, and the interaction time were optimized in  
glass chromatography vials by static procedures. The benzene vapor  
was absorbed from soil and vegetables samples with NAC-IL-FSF/  
SPME holder for 10 min at 80oC (10 mg of NAC and 0.1 g of ionic  
liquid in 0.5 mL of acetone coated on FSF). Then the benzene was  
desorbed and determined by GC-FID spectrometry. The extraction  
efficiency and absorption capacity of adsorbent were obtained 98.5%  
and 127.2 mg g-1, respectively. The high surface area of NAC and  
favorite interaction of aromatic chain in IL (π-π), caused to efficiently  
remove of benzene vapor by HS-SPME procedure as compared to  
other nanostructures.  
Available online 29 Mar 2021  
------------------------  
Keywords:  
Soil and vegetables,  
Nano activated carbon,  
Ionic liquid,  
Headspace solid phase micoextraction,  
Gas chromatography spectrometry  
other chemical activity [1-4]. The main material  
1. Introduction  
of refrigerants, plastics, adhesives, paints, and  
petroleum products is composed of VOCs [5].  
VOC’s such as benzene effect on human health and  
caused cancer in human body [6-8]. For many years,  
the analysis of trace volatile organic compounds  
(VOCs) in exhaled breath could potentially provide  
rapid screening procedures to diagnose and monitor  
the diseases of the lungs. The previous research  
showed that the earlier detection VOCs with GC-  
Recently different sources of volatile organic  
compounds (VOC’s) such as benzene released  
in atmospheric air. VOC’s consist of dangerous  
compounds which were produced due to the  
leaking gasoline vapor from the car engine or  
*Corresponding Author: Mehdi Ranjbar  
Benzene extraction in environmental samples by HS-SPME  
Afsaneh Afzali et al  
69  
MS caused to decrease the different types of cancer  
in human body. The most diagnostic tools cannot  
detect the cancer disease in primary stages. Various  
types of biomarkers including peptides, DNA,  
RNA, and cells are used in the diagnosis of cancer  
in human body [9]. The high concentration of  
BETX (benzene, toluene, Ethylbenzene, Xylenes)  
can be absorbed by skin, lungs and gastrointestinal  
system from air, waters and foods. The VOCs can be  
accumulated in liver, renal, and CNS and caused to  
dysfunction in human organs. Benzene vapor cause  
to lymphoma, anemia, the acute leukemia in humans  
and classified as high risk factor material which  
was reported by international agency for research  
on cancer (IARC) [10,11]. The different cancers  
may be generated by exposure to benzene in the  
indoor air. Among the BTEX compounds, benzene  
is the most dangerous material and cause to bone  
damage, dysfunction of CNS, damage of liver and  
respiratory tract. Based on US occupational safety  
and health administration (OSHA) and centers for  
disease control and prevention, national institute  
for occupational safety and health(NIOSH), the  
average of 1.0 ppm benzene in air was selected  
as the permissible exposure limit (PEL) [12].  
Many techniques such as extraction, adsorption,  
degradation, the catalytic oxidation, the adsorptive  
concentration-catalytic oxidation, the photocatalytic  
oxidation, and the plasma catalytic oxidation were  
used for removal and determination of VOCs in  
water samples [13]. The important sources of  
benzene include, the petroleum company, benzene  
tanks, petrochemical factories and gas pipes [14].  
Moreover, the low value of BTEX compounds in  
the water, soil and vegetables is very hazardous and  
must be controlled [15]. Nanoparticles (NPs) have  
been highly used for removal of environmental  
pollutants such as VOCs from air and waters. Due to  
the unique properties of NPs, the adsorption processe  
was obtained with high efficiency and recovery [16].  
The cupric oxide nanoparticles (CuONPs) have been  
used for adsorptive removal of benzene and toluene  
from aqueous environments [17]. Due to previous  
studies, the different methods such as, adsorption  
[18,19], the photo-catalytic oxidation and thermal  
oxidation [20] were used for removal of VOC’s  
or BTEX in environment matrixes. Teimoori et al  
(2020) showed that the benzene can be extracted  
and determined in waters and wastewater samples  
based on functionalized carbon nanotubes (R-CNTs)  
using GC-FID. They observed that under optimal  
conditions, the adsorption efficiency of CNTs@  
PhSAand CNTs for benzene was obtained 97.7% and  
20.6 % in water samples, respectively [15]. Recently,  
the activated carbon based on micro pores and  
heterogeneous surface functional groups was used  
for benzene extraction in environmental samples  
such as water and wastewater samples [21, 22]. Also,  
the activated carbon was most commonly used as  
absorbent for VOC’s removal from air and waters.  
By previous researches, the adsorption capacity of  
activated carbon was reported and depended on its  
surface area, pore volume, porosity and chemical  
functional groups. In addition, the other nano-carbon  
structures such as MWCNTs, graphene (NG) and  
carbon quantum dots (CQDs) were used for BTEX  
removal from environment matrixes [23, 24].  
In this study, the novel adsorbent based on NAC-IL  
coated on FSF/SPME holder was used for benzene  
extraction/separation/determination in soil and  
vegetables samples by HS-SPME procedure coupled  
to GC-FID. Validation methodology was confirmed  
by spiking of samples.  
2. Experimental  
2.1. Apparatus  
Gas chromatography based on air /gas loop injection  
with flame ionization detector was used for benzene  
analysis in air (Agilent GC, 7890A, GC-FID,  
Netherland). The sampling valves introduced a  
sample into the carrier gas stream and valves were  
also used to inject sample gases/ liquids in gas  
streams. The split/split less injector, FID detector,  
and a column of PDS (50 m × 0.2 mm; poly dimethyl  
siloxane) were selected for benzene determination  
by Agilent GC. The ultra-pure hydrogen gas (H2  
)
with flow rate of 1.0 mL min–1 was used as a carrier  
gas. For batch or static system, the different volumes  
of PTFE vials (parker) were purchased from Sigma,  
Germany.  
Anal. Method Environ. Chem. J. 4 (1) (2021) 68-78  
2.4. Characterization  
70  
2.2. Reagents and Materials  
All chemicals were purchased from Merck, and  
Sigma Aldrich companies, Germany. The stock  
solution of benzene (ppm, mgL-1) was prepared (0.1,  
0.2. 0.5, 1.0, 1.5, 2.0, 2.5, 3.0 ppm) and placed on  
vials as calibration curve of benzene by HS-SPME-  
GC-FID procedure. Benzene solution (99.7%) was  
purchased from Sigma and then, the eight solutions  
of benzene as standard calibration were prepared  
before proposed procedure. The other chemicals  
such as HNO3, HCl, acetone, methanol and ethanol  
with high purity (99%, GC grade) were purchased  
from Merck (Germany). The sorbent of NAC was  
synthesized by RIPI Nano laboratory. The NAC  
(≈50 nm), with 80% purity were synthesized. The  
characterizations of NAC were achieved by different  
spectra such as XRD, SEM and TEM. Ionic liquid  
(3-triphenylphosphonio-propane-1-sulfonate;  
C21H21O3PS; CAS N: 116154-22-4, MW:384.43, 5 g)  
Was purchased from Sigma Aldrich, Germany (Fig.  
1).  
X-ray diffraction (XRD) patterns were recorded  
on a Seifert TT 3000 diffractometer (Ahrensburg,  
Germany) using nickel filtered Cu-Kα radiation of  
wavelength 0.1541 nm. The textural properties of  
the sorbent including surface area, pore volume, and  
pore size distribution were determined by nitrogen  
adsorption–desorption isotherms using BELSORP-  
mini porosimeter (Bell Japan, Inc.). Prior to analysis,  
the samples were degassed under vacuum at 300  
°C for 4 hours until a stable vacuum of 0.1 Pa was  
reached. The specific surface areas and pore volume  
of the sorbents were calculated by the Brunauer-  
Emmett-Teller (BET) and Barrett-Joyner-Halenda  
(BJH) methods, respectively. The BET surface area  
of NAC was determined using a MicrometricsASAP  
2010 system. Scanning electron microscopy (SEM,  
Phillips, PW3710, Netherland) was used for surface  
image analysis of the sorbents. The morphology  
of sorbent was examined by transmission electron  
microscopy (TEM, CM30, Philips, Netherland).  
2.3. Synthesis of Nano activated carbon (NAC)  
Activated carbons (ACs) was synthesized by  
the carbonized method for 2.0 h at 600 °C  
by activating at 900 °C in a furnace. The  
carbonized chars were followed by typically  
heats biomass feedstock in a kiln (pyrolysis) at  
temperatures between 300-800°C by Ar gas. The  
produced material was also known as charcoal  
(porous). Firstly, 20 g of raw powders prepared  
and placed in the porcelain crucible, then  
was heated up to 600°C per minute and hold  
for 2.0 hours. By decreasing temperature  
up to 25oC, the product is ready for weight.  
The activation of ACs based on microwave  
heating method caused to create the Nano  
activated carbon (NAC) by previous works. First,  
the carbonized sample was mixed with KOH  
(CS/KOH; ratio 1:3; wt/wt). By heating, the  
NAC was carried out at 800 °C (rate: 25 °C/  
min; hold: 1h) in a tube furnace and cooling  
down to room temperature under N2 flow rate  
(0.5 Lmin-1) [25,26].  
2.5. Benzene Extraction Procedure  
By procedure, 10 mg of NAC and 0.1 g of ionic liquid  
in 0.5 mL of acetone were mixed in glass tube. Then  
FSF was put into mixture and temperature increased  
up to 55oC. After vaporization of acetone, the NAC/  
IL was coated on FSF/SPME holder. When the probe  
of NAC-IL-FSF/SPME fixed in head space of GC  
vial, 1 g of powder samples (soil, vegetables) were  
placed in the bottom of vial and were closed in glass  
vial, tightly. The temperature of vial was increased  
up to 80oC by heat power accessory and benzene in  
soil and vegetables samples which were vapored/  
adsorbed by NAC/IL–SPME in head space of vial  
for 10 min. Then, the probe of NAC/IL introduced  
to injector of GC and benzene was determined by  
GC-FID (Fig. 1). The temperatures of GC injector  
and detector were tuned up to 200°C and 240°C,  
respectively. The temperature programming of oven  
was adjusted between 50- 220°C for 20 min. Based  
on results, benzene can be efficiently absorbed on the  
NAC/IL adsorbents with high recovery of more than  
95%. The concentration of benzene according to the  
calibration curve was calculated and evaluated.  
Benzene extraction in environmental samples by HS-SPME  
Afsaneh Afzali et al  
71  
Fig.1. The procedure of benzene extraction in soil and vegetables samples based  
on NAC-IL-FSF/SPME by HS-SPME/GC-FID  
C-H  
C=O  
O-H  
C=C  
C-O  
4000  
3500  
3000  
2500  
2000  
1500  
1000  
500  
Wavenumber (cm-1)  
Fig.2. The FTIR spectrum of NAC  
The C=O stretching of COOH group shown in  
Figure 2 at 1710 cm-1 bond and peak at 1058 cm-1  
was related to the C–O vibration mode. The peak at  
1613 cm-1 belonged to C=C bond in benzene rings  
which was characterized by stretching vibration.  
The bands from 500 cm-1 to 850 cm-1 belonged to  
C-H and CH=CH2 vibrations in aromatic rings.  
3. Results and Discussion  
3.1. FTIR of ACNPs  
The FTIR spectrum of NAC was shown in  
Figure 2. The band at 3430 cm-1 was related to the  
stretching vibration of OH group. The band at 2909  
cm-1 and 2839 cm-1 were related to asymmetric and  
symmetric C–H stretching vibration of CH2 bond.  
Anal. Method Environ. Chem. J. 4 (1) (2021) 68-78  
72  
3.2. SEM and TEM of NAC  
3.3.1. The effect of NAC and IL amount  
FE-SEM and HR-TEM were used for  
morphological study of prepared NAC. The FE-  
SEM images of the synthesized NAC sample was  
shown in Figure 3. The FE-SEM images of NAC  
sample displayed small broken pieces of particles  
with irregular shapes, which can significantly  
affect the pore characteristics (e.g., pore size  
distribution and average pore diameter, Fig.3a).  
The NAC appeared to have many different  
sizes of pores, indicating that the structure had  
been destroyed and a dense porosity was formed  
through KOH activation. In order to observe the  
structure of NAC adsorbents, HR-TEM imaging  
was used. The HR-TEM image (Fig.3b) clearly  
shows the graphene-like structure with a 2D  
morphology, and the image with 50 nm scale  
confirms the existence of intermittent graphitic  
layers and porous structure.  
As high extraction, the amount of NAC and IL coated  
on FSF has been optimized for benzene concentration  
between 0.1- 3.0 mg g−1. Therefore, 2-25 mg of NAC  
and 0.02-0.2 g of ionic liquid in 0.5 mL of acetone  
were coated on FSF for benzene extraction in  
food, vegetable, and soil samples by the HS-SPME  
procedure which was coupled to GC-FID. The results  
showed the high recovery for soil/food /vegetable  
samples were obtained by 8 mg of NAC and 80 mg  
of ionic liquid for benzene adsorption by purposed  
procedure. So, 10 mg of NAC and 100 mg of ionic  
liquid coated on SFS was used for further work  
(Fig.4). The extra amount of NAC and ionic liquid  
had no effect on the extraction/adsorption efficiency  
of benzene from soil, food and vegetable samples.  
3.3.2.The effect of temperature  
The temperature is the main parameter for  
adsorption and desorption benzene from adsorbent  
by HS-SPME/GC-FID. The results showed the best  
adsorption of benzene from 1 g of powder soil and  
vegetables was achieved at 60-80oC in batch system  
for 10 min. After 10 min, extra time had no effect  
on the adsorption efficiency of benzene by NAC-IL-  
FSF. Also, increasing temperature more than 80oC  
caused to reduce adsorption efficiency by NAC/  
3.3. Optimization of benzene extraction  
All effected parameters such as the sorbent mass,  
amount of sample, the temperature, kind of ionic  
liquid, and time interaction were optimized in glass  
vials by static procedures. The benzene vapor was  
absorbed/extracted from 1 g of soil and vegetables  
samples with NAC-IL-FSF/SPME prob.  
Fig.3a. The FE-SEM images of NAC sample  
Fig.3b. The HR-TEM images of NAC sample  
Benzene extraction in environmental samples by HS-SPME  
Afsaneh Afzali et al  
73  
Fig. 4. The effect of NAC- IL amount for benzene extraction based  
on NAC-IL-FSF/SPME in soil/food /vegetable samples by HS-SPME/GC-FID  
Fig. 5. The effect of temperature for benzene extraction in soil/vegetable samples  
based on NAC-IL-FSF/SPME by HS-SPME/GC-FID  
IL. So, 70oC was selected as optimum temperature for  
benzene adsorption by NAC/IL in batch system (Fig. 5).  
Moreover, the adsorbed benzene on NAC-IL-FSF based  
on HS-SPME can be desorbed in injector of GC-FID  
at 200oC in presence of N2 or Ar gas. The temperature  
programming of oven was adjusted between 50-  
220°C for 20 min. The results showed that by  
decreasing temperature less than 60oC, the recovery  
decreased up to 72.2% for 10 min and increased more  
than 95% for 24 min. In addition, after vaporization  
benzene in vial air hold for 2-3 min at 70-80oC and  
then the temperature in batch system reduced up to  
50oC for 7 min. Finally, the absorbed benzene on SFS  
probe was desorbed and determined by introducing to  
injector of GC-FID. The extraction efficiency and the  
absorption capacity of NAC/IL were obtained more  
than 95% and 127.2 mg g-1, respectively. The results  
showed that the absorption capacity of NAC and IL  
were separately achieved at 72.6 mg g-1 and 58.3 mg  
g-1, respectively. So, in dynamic system, the values  
depended on flow rate of gas which was lower than  
batch system and must be optimized.  
Anal. Method Environ. Chem. J. 4 (1) (2021) 68-78  
74  
3.3.3.The effect of reaction time  
IL-FSF/SPME). The adsorbent was used for  
benzene extraction by HS-SPME/GC-FID. The  
results showed that the tri-phenyl of [PPP][S]  
with power π-π interaction of aromatic chain and  
different mass has more interaction with benzene  
aromatic cycles as compared to imidazolium rings  
in [EMIM][PF6], [BMIM][PF6] and [HMIM]  
[BF4]. Therefore, [PPP][S]/NAC with ratio of 100  
mg/10 mg was used for further work in optimized  
conditions which was shown in Figure 6.  
Due to boiling point of benzene and vaporization at  
lowtemperature, itcanadsorbonNAC/ILadsorbent  
in different time. The results showed that at low  
and favorite temperature the reaction time between  
benzene and adsorbent decreased and increased,  
respectively. By optimization, the minimum time  
for efficient recovery was obtained for 10 min at 70-  
80oC. When, the temperature reduced up to 50oC,  
all of benzene mass can be adsorbed on NAC/IL at  
24.5 min. Therefor the reaction time depended on  
π-π interaction in aromatic chain of IL or NAC and  
physical adsorption of NAC. On the other hand,  
there is relationship between temperature and π-π  
interaction and best recovery was obtained for 10  
min at 70-80oC.  
3.3.5.Validation in real samples  
The validation of HS-SPME/GC-FID method  
based on NAC-FSF/SPME and NAC-IL-FSF/  
SPME is important factor for extraction of  
benzene from soil and vegetables. By procedure,  
0.1-3 mg L-1 of benzene concentration was used  
for validation of methodology and the probe  
of SPME fixed in head space of GC vial. The  
25 number of soil, vegetables powders (rice,  
cabbage, spinach) and standard solution of  
benzene were placed in the bottom of vial and  
were closed in the glass vial, tightly. All samples  
were validated by spiking of real samples with  
standard solutions based on NAC/IL-FSF/SPME  
probe by HS-SPME/GC-FID (Table 1 and 2).  
Finally, extraction efficiency was calculated by  
3.3.4.The effect of different ionic liquids  
The effect of different ionic liquids for benzene  
extraction from soil and vegetables was evaluated.  
So, the different ionic liquids such as [EMIM]  
[PF6], [BMIM][PF6], [HMIM][BF4] and [PPP][S]  
as (3-triphenylphosphonio-propane-1-sulfonate;  
C21H21O3PS) were mixed with NAC and dilution  
diluted with 0.5 mL of acetone. Then, the acetone  
was vapored at 55oC and IL/NAC were coated  
on fused silica fiber of SPME holder (NAC-  
Fig. 6. The effect of different ionic liquids for benzene extraction  
in soil/food /vegetable samples based on NAC-IL-FSF/SPME by HS-SPME/GC-FID  
Benzene extraction in environmental samples by HS-SPME  
Afsaneh Afzali et al  
75  
Table 1. Validation of HS-SPME/GC-FID method based on NAC/IL-FSF/SPME for  
benzene extraction from soil and vegetables (1 g) near chemical industry  
Samples  
Benzene std. (mg L-1) *Found Method (mg L-1)  
Recovery (%)  
A-Soil  
----  
2.0  
----  
0.5  
----  
1.0  
----  
2.45 ± 0.09  
4.40 ± 0.23  
0.84 ± 0.05  
1.35 ± 0.06  
1.32 ± 0.07  
2.28 ± 0.13  
0.76 ± 0.04  
----  
97.5  
----  
B-Rice  
102.2  
----  
C-Cabbage  
D-Spinach  
96.0  
----  
0.5  
1.24 ± 0.07  
95.8  
E-Eucalyptus  
----  
1.85 ± 0.11  
2.83 ± 0.14  
----  
2.0  
98.3  
* Mean of three determinations ± confidence interval (P = 0.95, n = 5)  
Table 2. Validation of HS-SPME/GC-FID method based on NAC-FSF/SPME  
for benzene extraction from soil and vegetables (1 g) near chemical industry  
Samples  
A-Soil  
Benzene std. (mg L-1)  
*Found Method (mg L-1) Recovery (%)  
----  
1.5  
----  
0.5  
----  
1.0  
----  
1.72 ± 0.08  
3.19 ± 0.16  
0.59 ± 0.03  
1.07 ± 0.05  
0.91 ± 0.06  
1.93 ± 0.12  
0.52 ± 0.03  
----  
98.2  
----  
B-Rice  
96.0  
----  
C-Cabbage  
D-Spinach  
102  
----  
0.5  
1.01 ± 0.07  
1.27 ± 0.12  
98.0  
E-Eucalyptus  
----  
----  
1.5  
2.83 ± 0.14  
98.3  
* Mean of three determinations ± confidence interval (P = 0.95, n = 5)  
determining of benzene concentration by GC-FID  
in soil and vegetables. The efficient recovery of  
spiked samples had satisfactorily results with high  
accuracy and precision, which indicated the ability  
of HS-SPME/GC-FID method based on NAC/IL-  
FSF/SPME adsorbent for benzene extraction from  
environmental samples. After desorption of benzene  
from NAC/IL-FSF/SPME probe in GC injector, the  
concentration of benzene was simply determined by  
GC-FID. For validation, the results based on NAC/  
IL-FSF/SPME probe with GC-FID were compared  
to high resolution GC-MS (Table 3).  
Anal. Method Environ. Chem. J. 4 (1) (2021) 68-78  
76  
Table 3. Comparing of proposed procedure with GC-MS based on NAC/IL-FSF/SPME  
for benzene extraction from soil and vegetables (1.0 g) near chemical industry  
Samples  
A-Soil  
GC-MS (mg L-1)  
2.52 ± 0.08  
0.81 ± 0.04  
1.35 ± 0.06  
0.80 ± 0.03  
1.88 ± 0.08  
*Found Method (mg L-1)  
Recovery (%)  
96.1  
2.42 ± 0.12  
B-Rice  
0.83 ± 0.06  
102.4  
C-Cabbage  
D-Spinach  
E-Eucalyptus  
1.34 ± 0.07  
99.3  
0.76 ± 0.05  
95.0  
1.83 ± 0.13  
97.3  
* Mean of three determinations ± confidence interval (P = 0.95, n = 5)  
4. Conclussions  
6. References  
In this study, NAC/IL-FSF/SPME as a new  
adsorbent was used for benzene extraction from  
soil, and vegetables powders by HS-SPME/GC-  
FID procedure. Based on results, the simple, fast,  
sensitive and accurate results based on NAC/  
IL adsorbent were demonstrated. The absorption  
of benzene based on NAC/IL-FSF/SPME probe  
had efficient recovery in the optimized conditions  
(more than 95%). The parameters such as the  
amount of NAC/IL, the amount of soil and  
vegetables, the temperature, kind of ionic liquid,  
and time were studied. In optimized conditions,  
the maximum adsorption capacity of 127.2 mg  
g-1, 72.6 mg g-1 and 58.3 mg g-1 for NAC/IL, NAC  
and IL were obtained respectively, by HS-SPME/  
GC-FID. The results showed that the activity and  
reaction of NAC/IL for benzene extraction from  
soil/vegetables samples were more than NAC and  
IL in optimized conditions. Therefore, the applied  
and efficient procedure based on NAC/IL-FSF/  
SPME probe was used for extraction of benzene in  
environmental samples.  
[1] S. Sun, Z. Zhao, J. Shen, Effects of the  
manufacturing conditions on the VOCs  
emissions of particleboard, Bioresour., 15  
(2020) 1074–1084.  
[2] G.H. Li, W. Wei, X. Shao, L. Nie, H.L.  
Wang,  
A
comprehensive classification  
method for VOCs emission sources to  
tackle air pollution based on VOCs species  
reactivity and emission amounts, J. Environ.  
Sci., 67 (2018) 78–88.  
[3] G.D. Thurston, Outdoor air pollution:  
sources, atmospheric transport, and human  
health effects, international encyclopedia of  
public health, 2nd ed., Elsevier: Cambridge,  
MA, USA, 5 (2017) 367–377.  
[4] A.R. Schnatter, DC. Glass, G. Tang,  
RD. Irons, L. Rushton, Myelodysplastic  
syndrome and benzene exposure among  
petroleum workers: an international pooled  
analysis, J. Natl. Cancer Inst., 104 (2012)  
1724-1737.  
[5] K. Zhou, QG. Zhang, GL. Han, AM. Zhu,  
L. Liu, Pervaporation of water–ethanol  
and methanol–MTBE mixtures using poly  
(vinyl alcohol)/cellulose acetate blended  
membranes, J. Membrane Sci., 448 (2013)  
93-101.  
5. Acknowledgments  
The authors would like to thank from Amin  
Mokhtari Kheirabadi, Research Center for Nuclear  
Medicine, Tehran University of Medical Sciences,  
Tehran, Iran, and Hajar Bahrami andAtefeh Rasekh  
from Faraz Exir Samin Company, Isfahan, Iran.  
[6] J.E. Chang, D.S. Lee, S.W. Ban, J. Oh,  
M.Y. Jung, S.H. Kim, S.J. Park, K. Persaud,  
Benzene extraction in environmental samples by HS-SPME  
Afsaneh Afzali et al  
77  
S. Jheon, Analysis of volatile organic  
compounds in exhaled breath for lung  
cancer diagnosis using a sensor system,  
Sens. Actuators B Chem., 255 (2018) 800–  
807.  
benzenefromwatersandwastewatersamples  
based on functionalized carbon nanotubes  
by static head space gas chromatography  
mass spectrometry, Anal. Method Environ.  
Chem. J., 3 (1) (2020) 17-26.  
[7] Y. Sun, Y. Chen, C. Sun, H. Liu, Y. Wang,  
X. Jiang, Analysis of volatile organic  
compounds from patients and cell lines for  
the validation of lung cancer biomarkers by  
proton-transfer-reaction mass spectrometry,  
Anal. Methods, 11 (2019) 3188–3197.  
[8] J. Rudnicka, T. Kowalkowski, B. Buszewski,  
Searching for selected VOCs in human  
breath samples as potential markers of lung  
cancer, Lung Cancer, 135 (2019) 123–129.  
[9] T. Ahmad Mir, S. Ibrahim Wani, Early  
detection of lung cancer biomarkers through  
biosensor technology: a review, J. Pharm.  
Biomed. Anal., 164 (2019) 93–103.  
[16] M.J. Lashaki, J.D. Atkinson, Z. Hashisho,  
J.H. Phillips, J.E. Anderson, M. Nichols,  
The role of beaded activated carbon’s pore  
size distribution on heel formationduring  
cyclic adsorption/desorption of organic  
vapors, J. Hazard. Mater., 315(2016) 42–51.  
[17] L. Mohammadi, E. Bazrafshan, M.  
Noroozifar,  
A.  
Ansari-Moghaddam,  
F. Barahuie, D. Balarak, Adsorptive  
removal of benzene and toluene from  
aqueous environments by cupric oxide  
nanoparticles: kinetics and isotherm studies,  
J. Chem., 2017 (2017) 1-10. https://doi.  
org/10.1155/2017/2069519  
[10] M. Aivalioti, I. Vamvasakis, E. Gidarakos,  
BTEX and MTBE adsorption onto raw and  
thermally modified diatomite, J. Hazard.  
Mater., 178 (2010) 136-143.  
[18] J. Cheng, L. Li, Y. Li, Q. Wang, C. He,  
Fabrication of pillar arene-polymer-  
functionalized cotton ibers as adsorbents  
for adsorption of organic pollutants in  
water and volatile organic compounds in air,  
Cellulose, 26 (2019) 3299- 3312.  
[11] International Agency for Research on Cancer  
(IARC) monographs on the evaluation  
of carcinogenic risks to humans. overall  
evaluations of carcinogenicity, 1-42, 1987.  
[12] T.J. Lentz, M. Seaton, P. Rane, S.J.  
Gilbert, L.T. McKernan, C. Whittaker,  
Technical Report: the NIOSH occupational  
exposure banding process for chemical risk  
management, US, 2019.  
[19] R. Ashouri, H. Shirkhanloo, A.M. Rashidi,  
SA.H. Mirzahosseini, N. Mansouri,  
Dynamic and static removal of benzene from  
air based on task-specific ionic liquid coated  
on MWCNTs by sorbent tube-headspace  
solid-phase extraction procedure, Int. J.  
Environ. Sci. Technol., (2020) 1-14. https://  
doi.org/10.1007/s13762-020-02995-4  
[13] S. KP Veerapandian, N. De Geyter, J.M.  
Giraudon, J.F. Lamonier, R. Morent, The  
use of zeolites for VOCs abatement by  
combining non-thermal plasma, adsorption,  
and/or catalysis: a review, Catalysts, 9  
(2019) 98.  
[20] M. Mao, Y. Li, J. Hou, M. Zeng, X. Zhao,  
Extremely efficient full solar spectrum  
light driven thermocatalytic activity for  
the oxidation of VOCs on OMS-2 nanorod  
catalyst, Appl. Catal. B, 174 (2015) 496-  
503.  
[14] J.M.M.D. Mello, H. deLimaBranda, A.A.U.  
deSouza, A. daSilva, Biodegredation of  
BTEX compounds in a biofilm reactor-  
Modeling and simulation, J. Petrol. Sci.  
Eng., 70 (2010) 131–139.  
[21] I. Ghouma, M. Jeguirim, S. Dorge, L.  
Limousy, C. Matei Ghimbeu, A. Ouederni,  
Activated carbon prepared by physical  
activation of olive stones for the removal  
at ambient temperature, Comptes  
[15] S. Teimoori, A. Hessam Hassani, M  
Panaahie, Extraction and determination of  
of NO2  
Rendus Chim., 18 (2015) 63-74.  
Anal. Method Environ. Chem. J. 4 (1) (2021) 68-78  
78  
[22] O. Yahya Bakather, Adsorption of benzene  
on impregnated carbon nanotubes, Ain  
Shams Eng. J., 11 (2020) 905-912.  
[23] M. Bagheri, H. Shirkhanloo, J. Rakhtshah,  
Air pollution control: The evaluation  
of TerphApm@ MWCNTs as a novel  
heterogeneous sorbent for benzene removal  
from air by solid phase gas extraction, Arab.  
J. Chem., 13 (2020) 1741-1751.  
[24] Y. Liu, J. Zhang, X. Chen, J. Zheng, G.  
Wang, and G. Liang, Insights into the  
adsorption of simple benzene derivatives  
on carbon nanotubes, RSC Adv., 4 (2014)  
58036-58046.  
[25] Y. Kan, Q. Yue, B. Gao, Q. Li, Preparation  
of epoxy resin-based activated car-bons  
from waste printed circuit boards by steam  
activation, Mater. Lett., 159 (2015) 443-446.  
[26] J.M. Valente Nabais, P.J.M. Carrott,  
MM.L. Ribeiro Carrott, J.A. Menéndez,  
Preparation and modification of activated  
carbon by microwave heating, Carbon,  
42 (2004)1315-20.