鸟粪石沉淀法预处理高氨氮废水的镁盐研究

Study on magnesium agents for the pretreatment of high-strength ammonia wastewater by struvite precipitation

药剂费用一直是限制鸟粪石法处理高氨氮废水实际应用的主要因素。实验采用鸟粪石沉淀法预处理高氨氮废水,以磷酸氢二钠作为磷盐,就不同镁盐对高氨氮废水的处理效果进行了分析比较。实验结果表明,将氯化镁与氧化镁联用作为新型镁盐时,有很大的优势。在n(N)∶n(P)∶n(Mg)=1∶1∶1.5,n(MgCl2)∶n(MgO)=1∶2,反应时间为30 min条件下,氨氮的去除率可以达到90%以上,与常规单独采用氯化镁的处理方法相比,镁盐药剂费用可节约2/3以上。

The ment of high-strength gents on the removal method, when using cost of chemicals has limited the application of struvite precipitation method for the treatammonia wastewater. This study investigated the effect of several different magnesium a- of ammonia in the treatment of high-strength ammonia wastewater by struvite precipitation Na2HPO4 · 12H2O as the source of orthophosphate. The costs of chemicals were also com- pared. The experimental results indicated that combination of MgCl2 and MgO has great advantage in both ammonia removal and cost reducton. Under the following conditions ： the molar ratio of N： P： Mg = 1 ： 1 ： 1.5, the molar ratio of MgC12： MgO = 1 ： 2, and the reaction time = 30 rain, the removal rate of ammonia nitrogen was up to 90%. Compared with the common method using MgCl2 , more than two-thirds of chemical cost was saved.