微塑料对沸石吸附水体氨氮的影响及其机制  

Effect of Microplastics on Ammonia Nitrogen Adsorption by Zeolite in Water and Its Mechanism

作　　者：练建军[1,2] 谢诗婷 吴培 孟冠华 陈波[1,2] Mechanism LIAN Jian-jun;XIE Shi-ting;WU Pei;MENG Guan-hua;CHEN Bo(Engineering Research Center of Biofilm Water Purification and Utilization Technology of Ministry of Education,Anhui University of Technology,Maanshan 243032,China;College of Energy and Environment,Anhui University of Technology,Maanshan 243032,China)

机构地区：[1]安徽工业大学生物膜法水质净化及利用技术教育部工程研究中心,马鞍山243032 [2]安徽工业大学能源与环境学院,马鞍山243032

出　　处：《环境科学》2024年第4期2195-2202,共8页Environmental Science

基　　金：国家自然科学基金项目(51709001);安徽省自然科学基金项目(2208085ME154);生物膜法水质净化及利用技术教育部工程研究中心开放基金项目(BWPU2021KF08)。

摘　　要：以自然环境广泛存在的聚苯乙烯微塑料和丝光沸石为吸附剂,通过序批式吸附实验对比研究了微塑料和沸石两种单一体系,以及沸石和微塑料共存的复合体系下吸附剂分别对氨氮吸附过程的影响及其机制.结果表明,在3种体系下吸附剂对氨氮的吸附过程均符合准二级动力学模型以及Freundlich等温吸附模型.单一和复合体系下沸石对氨氮的吸附是吸热熵增过程,而微塑料吸附氨氮是放热和熵减的过程;沸石(74.85%)和复合体系吸附剂(82.68%)对氨氮的去除率在pH=6时均达最大值,而微塑料吸附氨氮随pH的提高而逐渐增大;腐殖酸对沸石吸附氨氮具有明显的抑制作用,去除率从60.29%降低至17.35%,而对微塑料的吸附作用影响较小.傅里叶红外光谱(FTIR)和X射线衍射(XRD)分析结果表明,沸石主要通过氢键和静电引力吸附氨氮,而微塑料通过影响沸石表面O—H和Si/Al—O基团改变了其对氨氮的吸附性能.With polystyrene microplastics and mordenite widely existing in the natural environment as adsorbents,the effects of the adsorbent on the ammonia nitrogen adsorption process in two single systems of microplastics and zeolite,as well as in the composite system of zeolite and microplastics coexisting,and their mechanisms were studied using a sequencing batch adsorption experiment.The results indicated that the adsorption process of ammonia nitrogen by the adsorbent in all three systems conformed to the pseudo-secondorder kinetic model and the Freundlich isothermal adsorption model.The adsorption of ammonia nitrogen by zeolites in both the single and composite systems was a process of endothermic entropy increase,whereas the adsorption of ammonia nitrogen by microplastics was a process of exothermic and entropy decrease.The removal rates of ammonia nitrogen by zeolite(74.85%)and the composite system adsorbent(82.68%)reached their maximum at pH=6,whereas the adsorption of ammonia nitrogen by microplastics gradually increased with the increase in pH.Humic acid had a significant inhibitory effect on the adsorption of ammonia nitrogen by zeolite,with a removal rate reduced from 60.29%to 17.35%,whereas its effect on the adsorption of microplastics was relatively small.The results of Fourier transform infrared spectroscopy(FTIR)and X-ray diffraction(XRD)analysis indicated that ammonia nitrogen was mainly adsorbed by zeolite through hydrogen bonding and electrostatic attraction,whereas microplastics altered their adsorption performance for ammonia nitrogen by affecting the O—H and Si/Al—O groups on the surface of zeolite.

关 键 词：沸石 微塑料 氨氮 吸附 影响机制 聚苯乙烯(PS) 

分 类 号：X131.2[环境科学与工程—环境科学]