MAP Precipitation from Landfill Leachate and seawater bittern waste

摘要

The leachates generated at Hong Kong landfill sites contain high strength of ammonium-nitrogen(NH_4~+-N) over 3,000 mg 1~-1 and are generally inhibitive to most biological treatment processes. To remove the NH_4~+-N from the landfill leachates and also recover the nitrogen as a struvite fertilizer, a lab-scale study was performed to investigate the feasibility of NH_4~+-N removal and struvite crystallization using different magnesium sources. Three combinations of chemicals, MgCl_2·6H_2O+Na_2HPO_4·12H_2O, MgO+H_3PO_4 and MgSO_4·7H_2O+Ca(H_2PO_4)·H_2O, were were first used at different molar ratios to Precipitate NH_4~+-N from the leachate.