Removal of Lead and Nitrate from Simulated Lead- and Nitrate-Containing Wastewater via Hydroxide Precipitation

Abstract

Lead and nitrate are pollutants that are commonly found in wastewater, and these pollutants pose significant risks to humans, animals, plants, and the environment. Therefore, it is essential to treat the wastewater to remove these toxic substances. This study utilized hydroxide precipitation for the removal of lead and nitrate from simulated lead- and nitrate-containing wastewater through jar testing. The effects of pH, lead nitrate (Pb(NO3)2) concentration, and precipitant-to-metal ([P]/[M]) ratio were examined. The hydroxide precipitation effectively removed lead and nitrate by forming basic lead nitrate precipitates, such as lead hydroxide nitrates and lead oxide hydroxide nitrates, and operated efficiently at a pH of around 8.0. Lead and nitrate removal was highly effective and primarily influenced by the [P]/[M] ratio, with [P]/[M] of 1.0 as the optimum condition. Varying the lead nitrate concentrations resulted in a higher sludge volume compared to other parameters; however, it was only significant in nitrate removal with an optimum concentration of 0.07 M.