The Removal of High NH3-N Concentration in Landfill Leachate by Chemical Precipitation
The municipal landfill leachate concentration was 1670mg / L, NH3-N in leachate was fomed MgNH4PO4· 6H2O crystal precipitation by adding MgSO4 · 7H2O and Na2HPO4 · 12H2O. pH value, reaction timeand chemical dosage ratio was discussed. The results shows that the suitable reaction pH value is between 8 and 9.When PH value is too high, the crystal structure would bedest- ructed,it will make the fixed ammonia escaped from MgNH4PO4. Mg2+: NH4 +: PO43-= 1.4:1:1.4 is the best choise under the conditions of pH 8.5, reaction time =20 min.The concentration of NH3-N in leachate was decreased from 1671Mg / L to 175Mg / L,the removal rate reaches to 98.5%.
Zhenyu Du and Chengbin Li
W. H. Song et al., "The Removal of High NH3-N Concentration in Landfill Leachate by Chemical Precipitation", Advanced Materials Research, Vol. 281, pp. 305-308, 2011