废水中氨氮沉淀的影响因素

以MgCl2和Na2HPO4为沉淀剂,用实验室模拟废水研究了影响氨氮沉淀的因素,包括沉淀pH值、沉淀剂的添加量及氨氮的原始质量浓度.结果表明,沉淀pH值是影响氨氮沉淀的主要因素,它影响氨氮的沉淀率、残余氨氮浓度、Mg2 和PO3-4的沉淀率和残余量以及沉淀后水的pH值.最佳沉淀pH值为11.氨氮的初始质量浓度在1 000 mg/L以下时,随其降低氨氮的沉淀率和残余氨氮质量浓度都降低;低于100mg/L时沉淀率明显降低,但残余氨氮质量浓度可以达到5mg/L,且变化不再明显.

Factors Influencing Ammonia Nitrogen Precipitation from Simulated Wastewater

In the laboratory and with a simulated wastewater as samples, the factors influencing the precipitation of ammonia nitrogen from wastewater were investigated with MgCl2 and Na2HPO4 as precipitants. These factors studied include the pH of precipitation, the dosage of precipitants, and the initial NH4 -N concentration of waste-water. The result shows that the pH of precipitation is the key factor and it determines the precipitation rate of NH4 -N, the remaining concentration, the removal rate and the remaining concentration of Mg2 and PO43-. The optimum pH is 11. When the initial NH4 -N concentration is less than 1 000 mg/L, both the precipitation rate and the residual concentration of NH4 -N decrease with decreasing the initial concentration. When the initial NH4 -N concentration is less than 100 mg/L, the precipitation rate decreases dramatically, but the minimum residual concentration is 5 mg/L and remaining the same.