基于超磁分离磁性4A分子筛/壳聚糖吸附氨氮  

Adsorption of Ammonia Nitrogen on Magnetic Composite of 4A-molecular-sieve and Chitosan in Super-magnetic Separation System

作　　者：马加加 柯博瀚 钟锦堂 刘曦 李绍秀[3] MA Jiajia;KE Bohan;ZHONG Jintang;LIU Xi;LI Shaoxiu(Guangzhou Water Planning&Design Institute Co.Ltd.,Guangzhou 510640,China;Guangdong YSD Surveying&Designing Co.,Ltd.,Foshan 528000 China;School of Civil and Transportation Engineering,Guangdong University of Technology Gangzhou 510006,China)

机构地区：[1]广州市水务规划勘测设计研究院有限公司,广东广州510640 [2]广东粤水电勘测设计有限公司,广东佛山528000 [3]广东工业大学土木与交通工程学院,广东广州510006

出　　处：《环境科学与技术》2022年第3期204-211,共8页Environmental Science & Technology

摘　　要：文章通过水热合成法制备组成为四氧化三铁、4A分子筛及壳聚糖的磁性复合材料(M-CS-MS),对M-CS-MS进行X-射线衍射、红外光谱与磁强表征,研究M-CS-MS吸附去除氨氮的影响因素,探讨吸附动力学、热力学与吸附机理。以M-CS-MS为磁种进行超磁分离处理模拟废水。结果表明:5 g/L的M-CS-MS吸附氨氮,氨氮去除率达到80%以上。氨氮的去除率随着M-CS-MS投加量增大而有所增大,随着氨氮初始浓度增大而下降,而吸附量却增大。pH值为6时,M-CS-MS对氨氮去除效果最佳。M-CS-MS磁性良好,可通过磁分离从水中回收。氯化钠溶液能有效再生M-CS-MS,在弱碱性下M-CS-MS再生效果最佳。M-CS-MS吸附-再生循环3次,氨氮去除率仍在70%以上。吸附过程遵循拟二级动力学模型和Freundlich吸附等温线,吸附为放热反应,存在物理吸附和化学吸附。以M-CS-MS为磁种的超磁分离工艺处理模拟废水,具有同步去除氨氮、浊度及高锰酸盐指数的效果。在M-CS-MS为6 g/L时,氨氮、浊度及高锰酸盐指数去除率分别在80%、96%、58%以上,且磁种可通过廉价的氯化钠溶液实现再生循环使用,以M-CS-MS为磁种的超磁分离工艺对于废水处理有较好的应用前景。A novel magnetic composite(M-CS-MS) consisting of ferroferric oxide, 4A-molecular-sieve and chitosan was developed by means of the hydrothermal synthesis method. It was characterized by X-ray diffraction, Fourier transform infrared spectroscopy and vibrating-sample magnetometer, respectively. When applied to treat some simulated wastewater,M-CS-MS was investigated for the adsorption of ammonia nitrogen onto it in terms of the influencing factors, and the adsorption kinetics, thermodynamics and adsorption mechanism were discussed. As for the super-magnetic separation system for treating wastewater, in which M-CS-MS was used as magnetic seeding materials, the experimental results showed that the removal rate of ammonia nitrogen was more than 80% by adsorption with 5 g/L M-CS-MS. The removal rate of ammonia nitrogen increased with the increase of M-CS-MS dosage while decreased with the increase of initial concentration of ammonia nitrogen, but the adsorption amount increased. When pH value equaled six the removal effect of ammonia nitrogen was maximized. In addition, M-CS-MS had a good magnetic property and could be recovered by magnetic separation from water and M-CS-MS could be regenerated with sodium chloride solution, the regeneration efficacy being the best in weak alkaline solution;besides, after three adsorption-regeneration cycles, the removal rate of ammonia nitrogen could still maintain more than 70%. The study of adsorption process proved that the adsorption fit the pseudo-second-order kinetic model and Freundlich adsorption isotherm, it was a kind of exothermic reaction in which physical adsorption and chemical adsorption existed simultaneously. When M-CS-MS as magnetic seeds adopted(with the dosage of 6 g/L) in the supermagnetic separation system for treating the simulated wastewater, ammonia nitrogen, turbidity and CODMnwas simultaneously removed from the wastewater, with the removal rate being above 80%, 96% and 58%, respectively. The magnetic seeds can be regenerated by cheap sodium chloride solution

关 键 词：超磁分离 氨氮 吸附 4A分子筛 壳聚糖 

分 类 号：X703[环境科学与工程—环境工程]