以实际垃圾渗滤液为对象,采用MgSO4·7H2O和Na2HPO4·12H2O使NH3 -N生成MgNH4PO4·6H2O结晶沉淀的MAP(硫酸铵镁)法去除回收垃圾渗滤液中高浓度氨氨的效能,研究了pH、反应时间、药剂配比对NH3 -N去除率的影响.结果表明:MAP法回收垃圾渗滤液中NH3-N的适宜pH为8.5～9.5;过高的pH会破坏硫酸铵镁晶体结构,导致固定氨从结晶中游离,不利于氨氮的去除；在pH为8.5、反应时间为20 min、n(Mg2+)∶n(NH4+)∶n(PO43 -)=1.4∶1.0∶1.4的最佳条件下,渗滤液中NH3 -N的质量浓度由初始的1671mg/L降至30 mg/L,去除率达98.2％；同时回收的MAP可作缓释肥.%MgNH4PO4·6H2O crystal precipitation was formed to recycle NH3 - N in leachate by adding MgSO4·7H2O and Na2HPO4·12H2O. pH value, reaction time and chemical dosage ratio were discussed. The results show that the suitable reaction pH value is between 8.5 and 9.5. When pH value is too high, the crystal structure will be destroyed, making the fixed ammonia escape from MgNH4PO4· n(Mg2+ ): n (NE4+ ): n(PO4~3- ) = 1.4:1.0:1.4 is the best choice under the conditions of pH 8.5 and reaction time 20 minutes. The concentration of NH3 - N in leachate is decreased from 1671 mg/L to 30 mg/L, and the removal rate reaches 98.2%. The recycled MAP can be used as in multi-element compound fertilizer rnproduction.
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