Study on the landfill leachate pretreatment based on coagulation and MAP precipitation

摘要

Landfill leachate was pretreated with different coagulants and precipitation reagents in this paper. The experimental results demonstrated that CODcr was effectively removed from initial 12250mg/L down to final 9730.05mg/L, NH3-N from 340.85mg/L to 35mg/L, SS from 845 mg/L to 106.55 mg/L when PAC was dosed into the leachate firstly with the optimal leachate pH value for the coagulation about 8, the mixing intensity was controlled at 150r/min, mixing time 20min, coagulation time 45min, then analytical grade chemicals of MgCl2•6H2O and Na2HPO4 were used and the ratio of Mg²⁺ : NH4⁺ : PO4³⁻was controlled at 1.0: 1.5: 1.5.