Hassani, Mostafa, and Bahareh Azemi Motlagh. 2023. “Design and Construction of Pilot Sludge Drying Package for the Excess Sludge in Petrochemical Industries: Heavy Metals Determination in Sludge by Polarography and Atomic Absorption Spectrometry”. Analytical Methods in Environmental Chemistry Journal 6 (04), 52-64. https://doi.org/10.24200/amecj.v6.i04.315.