Abstract: The effect of additive NaCl on microwave-assisted removal of ammonia nitrogen by natural zeolite,including factors influencing adsorption and ion-exchange,was investigated.The results show that microwave-assisted can greatly improve the efficiency of zeolite denitrification.The best conditions are:microwave power 343 W,time 4 min,concentration of NaCl 4%,size of zeolite particles 0.1-0.15 mm,and the best removal efficiency is up to 99.70%.As a comparison,no NaCl addition but microwave auxiliary,the removal rate of ammonia nitrogen by zeolite is 76.46%. If only zeolite was employed the removal rate is 60.70%.So the increase of efficiency is significant,39%,15.76% respectively. The results of zeolite surface morphology and element measurements by SEM,EDS and XRD indicated that sodium chloride could improve microwave heating and ion exchange of zeolite.Its ion exchange capacity for ammonia at microwave condition increases greatly by NaCl.

Key words: zeolite, ammonia nitrogen, microwave, additives, recycled water treatment

摘要： 通过添加助剂NaCl在微波下对天然沸石进行加热制备环境材料,研究了微波后沸石对再生水中氨氮的去除效果。研究发现,助剂预处理可以大大提高微波沸石的脱氮效果。在沸石与NaCl溶液固液比1:50,NaCl溶液浓度4%,343 W的微波功率加热4 min的条件下,微波沸石环境材料对氨氮的去除效果最好,最佳去除率可达99.70%;单独进行343 W、4 min的微波加热沸石对氨氮的去除率为76.46%;相对于天然沸石,上述两种微波沸石对氨氮去除率分别提高了39%、15.76%。通过SEM、EDS、XRD等表征手段对微波前后的沸石分析发现,在微波加热过程中助剂氯化钠的加入使沸石颗粒表面更加松散,出现了更多的孔道,同时天然沸石Ca、Mg、P、S峰消失,主衍射峰强度有所减弱,出现了部分非晶化特征。

关键词: 沸石, 氨氮, 微波, 助剂, 再生水处理