Removal of Heavy Metals during Primary Treatment of Municipal Wastewater and Possibilities of Enhanced Removal: A Review

Resource reuse has become an important aspect of wastewater management. At present, use sludge in agriculture is one the major routes. Conventional municipal treatment does not involve any designated process for removal heavy metals, and these distribute mainly between effluent sludge. Enhanced metals during primary may decrease metal concentrations both from secondary promote long-term This review considers occurrence settling, together with possible technologies settlers their theoretical performance. The variation total dissolved fraction raw points to a need site-specific assessments appropriate improved removal. Studies examining speciation beyond dissolved/particulate are few. Missing or disparate information on parameters such as hydraulic retention time, pH composition return flows makes it hard generalize findings studies concerning settlers. Coagulation/flocculation low-cost sorbents were identified most promising methods enhancing settling. Based available data sorption be effective Cu Ni, while coagulation efficient Cd, Cr, Cu, Pb, Zn Hg (but Ni removal).