化学沉淀法处理高浓度氨氮废水的实验研究

Experimental Studies on Treatment of High Concentration Ammonia- NitrogenWastewater with Chemical Precipitation Method

采用氯化镁和磷酸氢二钠作为药剂对高浓度的氨氮废水进行化学沉淀处理,通过实验考察了废水的pH、初始氨氮浓度、沉淀剂配比与加入量等条件对去除效果的影响。结果表明:化学沉淀法是处理高浓度氨氮废水的有效方法,在pH为9.0,处理溶液中n(NH+4)∶n(Mg2+)∶n(PO3-4)=1∶1.3∶1.3的情况下,氨氮去除率最大,可达98.48%,但对于低浓度氨氮废水,化学沉淀法的去除率较低,可以采用生物法进一步深度处理。

In this paper, the method of magnesium ammonium phosphate sediment was adopted to treat the high concentration ammonia - nitrogen wastewater. Influences of the pH value, initial concentration of ammonia - nitrogen, the molar ratio of the sediment agents and its quantity added on the removal of ammonia - nitrogen in the waste water were investigated. And results showed that the sediment method of magnesium ammonium phosphate is an effective one for removal ammonia - nitrogen in the waste water. Under the optimum operating conditions with which solution pH value 9.0, the ionic molar ratio of the NH4＋ ,Mg2 ＋ ,PO3- , i.e. n（ NH4 ） ： n（Mg2＋ ）： n（PO43- ） being 1： 1.3： 1.3, the maximum value of ammonia - nitrogen removal could reach 98. 48%. And the precipitation of magnesium ammonium phosphate （ MgNH4PO4 · 6H2O） is a kind of effective controlled release fertilizer. But for the low concentration of ammonia nitrogen wastewater, the removal ratio of chemical precipitation is lower. Therefore, biological method is needed for the further treatment in depth.