Amirkabir University of Technology Amirkabir Journal of Mechanical Engineering 2008-6032 53 11 2022 01 21 Removal of Lead Heavy Metal from Wastewater by Crystallization Process and Investigation of the Effective Parameters Removal of Lead Heavy Metal from Wastewater by Crystallization Process and Investigation of the Effective Parameters 5349 5366 4397 10.22060/mej.2021.19314.7000 FA Parvaneh Khalati Faculty of Chemical and Petroleum Engineering, University of Tabriz, Tabriz, Iran Maryam Tahmasebpour تبریز-مهندسی شیمی Seyed Jamaledin Peighambarsoust Associate Professor of Polymer Science and Engineeringو Faculty of Chemical &amp;amp; Petroleum Engineering, University of Tabriz 0000-0001-7514-4445 Journal Article 2020 11 27 The increase in population and industrialization of societies have caused the production of large amounts of inorganic, organic, and biological pollutants. Lead is one of the heavy metals having high and long-term toxicity even at low concentrations which limits the reusability and recyclability of industrial wastewaters so it must be removed. In this study, the removal and recovery of Pb from synthetic wastewater by a new form of precipitation method named crystallization process in a batch system was investigated. This process has gained increasing attention in recent years because of accessibility, low cost, high efficiency, and no need to recover the used materials. The efficacy of removal was dependent on the factors such as <em>pH</em>, initial lead concentration, carbonate: lead molar ratio, and amount of seed crystals. The results of the experiments performed in this study showed that when the <em>pH</em>=8, the initial concentration of lead is 100 mg /L, the molar ratio of carbonate to lead is 3:1 and the amount of seed particles is 0.25 g dissolved in 100 ml, the lead removal efficiency is obtained as 99 %. The present study demonstrates that Pb can be successfully removed and recovered as PbCO3 crystals in a batch reactor. The increase in population and industrialization of societies have caused the production of large amounts of inorganic, organic, and biological pollutants. Lead is one of the heavy metals having high and long-term toxicity even at low concentrations which limits the reusability and recyclability of industrial wastewaters so it must be removed. In this study, the removal and recovery of Pb from synthetic wastewater by a new form of precipitation method named crystallization process in a batch system was investigated. This process has gained increasing attention in recent years because of accessibility, low cost, high efficiency, and no need to recover the used materials. The efficacy of removal was dependent on the factors such as <em>pH</em>, initial lead concentration, carbonate: lead molar ratio, and amount of seed crystals. The results of the experiments performed in this study showed that when the <em>pH</em>=8, the initial concentration of lead is 100 mg /L, the molar ratio of carbonate to lead is 3:1 and the amount of seed particles is 0.25 g dissolved in 100 ml, the lead removal efficiency is obtained as 99 %. The present study demonstrates that Pb can be successfully removed and recovered as PbCO3 crystals in a batch reactor. https://mej.aut.ac.ir/article_4397_402b0702500cd47ff36e689465afd783.pdf