MAP化学沉淀法处理氨氮废水的工艺研究

以氯化镁和磷酸氢二钠为沉淀剂,研究了磷酸铵镁(MAP)化学沉淀法去除模拟废水中氨氮的工艺条件。结果表明:MAP化学沉淀法对初始质量浓度为500～10000mg/L的氨氮废水有很好的适应性,能达到去除水体中高浓度氨氮的目的。氨氮初始浓度、pH值、反应温度、反应时间、沉淀剂投加比例等操作条件,对氨氮的去除率有明显影响,在实际操作中,控制反应温度为25～35℃,pH值为10,镁、氮、磷的量比为1.2∶1∶1.2较适宜,在此条件下反应20min,对初始质量浓度为1000mg/L的氨氮废水的去除率达98.7%。

Treatment Of ammonia-nitrogen containing wastewater by MAP chemical precipitation

With magnesium chloride and sodium hydrogen phosphate as precipitator, the process condition for magnesium ammonium phosphate(MAP) chemical precipitation removing ammonia-nitrogen from simulant waste-water was studied.The results showed that:ammonia-nitrogen with initial mass concentration of 500-10 000 mg / L in wastewater could be effectively removed by MAP chemical precipitation, and the process showed excellent adaptability;the operation conditions, including initial mass concentration of ammonia-nitrogen, pH value, reaction temperature, reaction time and concentration ratio of precipitator have apparent influence on ammonia-nitrogen removal.In actual operation, it is appropriate to control the operation conditions of temperature as 25-35 ℃, pH value as 10, n(Mg) ∶ n(N) ∶ n(P) as 1.2 ∶ 1 ∶ 1.2, as thus, the removal rate of ammonia-nitrogen with initial mass concentration of 1 000 mg / L in wastewater can be 98.7% after a 20 min reaction.