磷酸铵镁沉淀法预处理氨氮废水的研究

摘要

以某化肥厂氨氮废水为研究对象,采用磷酸铵镁(MAP)沉淀法去除废水中氨氮,同时合成磷酸铵镁(鸟粪石)晶体.沉淀后上清液测定氨氮和总磷含量.MAP法去除氨氮的最佳条件,结果表明,以MgCl2为镁盐,pH在10.5左右,n(P)∶n(N)=1.2.在此条件下,废水中氨氮去除率可达85.72%,废水氨氮浓度达到后期生化处理要求.扫描电镜和X射线衍射仪分析表明,生成的鸟粪石纯度较高,沉淀效果良好.%Using ammonion-nitrogen wastewater from chemical industry as the test subject,magnesium ammonium phosphate hexahydrate(MAP) was prepared by precipitation reaction.Concentration of ammonion-nitrogen was used in supernatant as the test subjects,the conclusion of the removal efficiency of ammonion-nitrogen under the optium reactive conditions was got.Optimal reaction conditions were determined as the following:using magnesium chlorideas magnesium sapH value 10.5;n(P)∶n(N)=1.2.Under the optimal reaction conditions the ammonion-nitrogen removal rate was 85.72%,and wastewater reached biochemical treatment after MAP precipitation.Combined with SEM and XRD analysis of the deposit crystals,generated at this time of struvite purity is higher,the precipitation effect is good.