粉煤灰合成沸石去除城市暴雨径流中氨氮

采用粉煤灰为原料,通过耦合碱熔-两步合成法制得3种合成沸石产品,并以合成沸石制备大粒径的功能填料。通过氨氮吸附速率实验和等温吸附实验探讨了合成沸石及功能填料的氨氮吸附速率和最大吸附容量(Qm),以功能填料构建模拟人工快速渗滤系统,研究其对城市暴雨径流中氨氮的去除效果。结果表明,合成沸石对氨氮的吸附速率极快,5min去除率约达到75%,氨氮最大吸附容量为11.36～16.13 mg/g;功能填料对氨氮的最大吸附容量有所下降,但氨氮吸附速率仍较快,应用于模拟人工快速渗滤系统时能在较高的水力负荷下快速去除城市暴雨径流中的氨氮。碱处理再生法更适于进行合成沸石功能填料原位再生,氨氮吸附容量一次再生率达到67%～87%。

Ammonia nitrogen removal from urban rainwater runoff by zeolites synthesized from fly ash

Three kinds of zeolites were synthesized from fly ash by combining fusion method and two-stage method,and then were used to prepare filter media.The rate and capacity of ammonia nitrogen adsorption by zeolite and filter media were assessed.The filter media were applied in rapid constructed infiltration system to investigate the performance of ammonia nitrogen adsorption in urban rainwater runoff.About 75% of ammonia nitrogen could be removed in the first 5 minutes,and the capacity reached 11.36~16.13 mg/g.The filter media could remove ammonia nitrogen from urban rainwater runoff under high hydraulic load although the capacity decreased.Alkaline treatment was more suitable for the regeneration of filter media,and 67%~87% adsorption capacity could be recovered.