THE BEHAVIOR OF HEAVY-METALS DURING WASTE-WATER TREATMENT .2. LEAD, NICKEL AND ZINC

Mechanisms of metal removal during sewage treatment are reviewed and the application of these mechanisms to lead, nickel and zinc removals are discussed. Sampling was performed at Whitlingham sewage treatment works (Anglian Water), Norwich, to assess the removal mechanisms of these metals, with reference to partitioning between particulate and soluble phases. Mass balances were performed as a means of quality control. It was concluded that lead was primarily associated with solids. However, it was solubilized during activated sludge treatment and this was possibly due to the addition of anaerobic solids in the overflow from a waste activated sludge consolidation tank. The soluble phases of nickel and zinc were not significantly affected by any of the processes in the works. © 1990.