海水改性沸石处理氨氮废水

沸石因具有独特的架状结构而表现出良好的选择吸附和离子交换性能,在废水处理中被广泛应用,但吸附容量偏低,需要进行改性。针对天然沸石的局限性,研究了不同改性方法对氨氮吸附的影响,确定了最佳的沸石改性方法,并进行了吸附等温模型,吸附动力学研究。结果表明,采用高温300℃焙烧后再用预处理后的海水浸泡24 h改性沸石去除氨氮效果最佳。当活化沸石投配量为10 g/L,接触时间为150 min,进水氨氮浓度为37.91 mg/L时,沸石对氨氮吸附容量为4.08 mg/g,氨氮去除率为90.45%;沸石及改性沸石对氨氮的吸附等温线符合Langmuir方程和准一级动力学方程。用海水来改性沸石的方法,不仅可提高沸石对氨氮的吸附容量和吸附速度,而且无任何添加药剂,具有简单易行、费用低廉的优点,为沸石在水处理工程中的应用提供技术支撑。

Treatment of ammonia-nitrogen wastewater by zeolite modified with seawater

Zeolite has a wide application in wastewater treatment because it has good performance of selective adsorption and ion exchange for its peculiar cage structure.However,modified zeolite is needed because natural zeolite has less adsorption capacity.Aiming at limitation of natural zeolite,the method of modification on absorbing ammonia nitrogen was presented.The optimal modified method for zeolite was confirmed.Meanwhile the process of adsorption equilibrium and kinetics for ammonia-nitrogen adsorption on zeolite were studied.The results show that the modified method which is calcined in 300 ℃ and then immersed 24 hours in the seawater can remove ammonia-nitrogen well.When amount of modified zeolite is 10 g/L,contact time is 150 minutes,influent concentration is 37.91 mg N/L,modified zeolite adsorption capacity for ammonia nitrogen is 4.08 mg/g,ammonia nitrogen removal rate is 90.45%.Its adsorption behavior comforms to Langmuir adsorption isotherm and pseudo first-order kinetics equation.It is confirmed that the modified method for natural zeolite with seawater has high adsorption capacity and adsorption rate for ammonia-nitrogen,and has the advantage of no additive medicaments,simple operation and low cost.This study will provide a theoretical reference for effectively removing ammonia-nitrogen from wastewater.