化学沉淀法去除废水中氨氮实验研究

Study on removal of ammonia-nitrogen from wastewater by chemical precipitation

针对化工领域氨氮废水的处理,在实验室探讨化学法(MAP)去除氨氮的操作条件。通过单因素实验和正交试验考察了pH值、反应药剂配比与氨氮去除率的关系。试验结果表明,以磷酸氢二钠和氯化镁作为沉淀剂,最佳的操作条件为:pH=9.0,n(Mg)/n(N)/n(P)=1.4/1.0/1.2,反应时间20min。初始氨氮浓度为89mg/L的废水,经过处理,氨氮的去除率可达94%。

To solve the problem of ammonia-nitrogen waste water treatment in chemical industry, the operation conditions of ammonia-nitrogen removal by MAP chemical precipitation method were investigated experimentally. The effects of pH value and reactants ratio on the removal efficiency of ammonia-nitrogen were studied through single factor tests and orthogonal tests. The results showed that the optimum operation conditions were pH=9.0, n（Mg）/n（N）/n（P）=1.4/1.0/1.2, reaction time 20 min with Na2HPO4.12H2O and MgCl2· 6H2O as the precipitator, and the removal efficiency of ammonia-nitrogen with original concentration of 89mg/L was up to 94% under above conditions.