磷酸镁铵沉淀法处理铁红含氨氮废水

Wastewater treatment of iron oxide red containing NH_4^+-N by magnesium ammonium phosphate

为了有效地去除氧化铁红废水中高浓度的氨氮,探讨了采用硫酸镁和磷酸氢二钠使废水中氨氮生成磷酸镁铵[Mg(NH4)PO4.6H2O]的化学沉淀去除法。通过单因素和正交实验表明:磷酸镁铵沉淀法对铁红废水中高浓度氨氮有较好的处理效果;pH对处理效果影响最大;当调整原废水在最佳条件,即pH为10,按镁、氮、磷物质的量比为1.1∶1.0∶1.3投加药品,搅拌反应10 m in,氧化铁红废水中氨氮质量浓度可由417.5 mg/L降到1.9 mg/L,去除率高达99.5%,同时得到的磷酸镁铵沉淀可以作为复合肥使用。

In order to remove the NH4^＋- N with high concentration in iron oxide red wastewater, the chemical precipitation method is adopted, e. i. the MgSO4 and NaH2PO4 are used to react with NH4^＋ - N in wastewater to form magnesium ammonium phosphate[ Mg（ NH4）PO4 ·6H2 O ]. The test made by single -factor and orthogonal design method shows that this precipitation method has a good treating effect and pH has an important effectiveness. The optimum conditions are as follows：pH 10,the ratio of n（Mg） ： n（N） ： n（P） = 1.1： 1.0： 1.3,agitation 10 min,thus,the concentration of NH4^＋ -N in iron oxide red wastewater can be reduced from 417.5 mg,/L to 1.9 mg/L,the removal rate of NH4^＋ - N can reach 99.5%. Meantime, the magnesium ammonium phosphate can be used as compound fertilizer.