鸟粪石沉淀法预处理中等浓度氨氮废水研究

Research of medium concentration ammonia nitrogen wastewater pretreatment by struvite precipitation

采用鸟粪石沉淀法预处理中等浓度氨氮废水,考察磷源、镁源、pH、反应时间、药剂投加比对处理氨氮废水的影响。结果表明,处理初始浓度200 mg/L的模拟氨氮废水,当以Na_2HPO_4·12H_2O和MgCl_2·6H_2O作为投加药剂,反应pH为10.0,反应时间10 min时,n(N)∶n(P)在1∶0.8~1∶0.85之间,n(N)∶n(Mg)在1∶1~1∶1.15之间有较好的处理效果。通过红外光谱、X射线粉末衍射仪等表征说明回收的产物为鸟粪石。采用该法预处理实际中等浓度氨氮废水,最佳n(N)∶n(P)∶n(Mg)摩尔比为1∶0.8∶1.05,处理后氨氮浓度符合企业所处化工园区的污水接管标准。

Medium concentration ammonia nitrogen wastewater was pretreated by struvite precipitation.The key factors of p H,reaction time,dosage,phosphorus sources and magnesium sources were investigated. The results showed that when the initial concentration of ammonia-nitrogen was 200 mg/L,Na_2HPO_4·12H_2O and MgCl_2·6H_2O were added as medicament,the reaction p H of 10. 0,the reaction time of 10 min,the molar ratio for n( N) ∶ n( P) of 1∶ 0. 8 ~ 1∶ 0. 85,n( N) ∶ n( P) of 1∶ 1 ~ 1∶ 1. 15 could achieve good result. The results of infrared spectrum and XRD analysis indicated that the recovery of the product was struvite. Pretreatment of medium concentration ammonia-nitrogen actual wastewater by this method,the optimum molar ratio for n( N) ∶ n( P) ∶ n( Mg) was 1 ∶ 0. 8 ∶ 1. 05,the residual concentrations was in line with the chemical industrial park wastewater pipe requirements.