由于汞的物理化学性质和对人体的毒副作用,汞减排已成为全球共识.当前除汞方法中,吸附法为一种较有潜力的方法.壳聚糖是一种天然的汞离子(Hg2+)吸附剂,以物理、化学手段改性后的衍生物更具有对环境中的汞吸附容量大,吸附效率高的优点.本文综述了壳聚糖及其衍生物脱除溶液中Hg2+的研究近况,介绍了壳聚糖物理(冷冻干燥、静电纺丝等)、化学修饰手段(交联和接枝等)以及与新型碳材料(碳纳米管、氧化石墨烯等)复合脱汞的最新研究,分析了壳聚糖及其复合物对水中Hg2+的去除效果和影响因素.最后,对壳聚糖吸附剂在汞污染治理中的研究作了展望.%Mercury emission reduction has become a global consensus due to the physiochemical properties of mercury and its side effects on humans.Adsorption is considered as a potential Hg2+ ions removal method.Chitosan is a natural Hg2+ ions adsorbent,and its Hg2+ ions adsorption capacity and efficiency can be improved by preparation of modified derivatives from physiochemical methods.Hg2+ ions adsorption by chitosan and its derivatives is now assumed to occur through several single or mixed interactions:the amino group (-NH2) and hydroxyl (-OH),which adsorb Hg2+ ions mainly through chelate,ion exchange or electrostatic force.The protonated amino group of chitosan and C =N group (Schiff base) of its derivatives may are the main selective functional groups responsible for Hg2+ ions adsorption.In this study,we review the research progress of Hg2+ ions removal by chitosan and its composites in the field of water treatment,and introduce the means of chitosan physiochemical modification (e.g.freeze drying,electrostatic spinning,crosslinking or grafting) as well as composite mercury removal by new carbon materials (e.g.carbon nanotubes,graphene oxide) in latest research.The removel efficiency and influential factors of Hg2+ ions removel by chitosan and its derivatives are discussed in detail.Finally,we discuss the research prospects of chitosan adsorbent materials in treatment of mercury pollution.
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