壳聚糖包覆纳米铁镍双金属的迁移性能及其降解地下水中三氯乙烯的研究  

Study on Mobility of Chitosan Coated Fe/Ni Bimetal Nanoparticles and Their Reactivity for Trichloroethylene Degradation in Groundwater

作　　者：周轩亦 李哲[1,2] 陈家玮 ZHOU Xuanyi;LI Zhe;CHEN Jiawei(State Key Laboratory of Biogeology and Environmental Geology,China University of Geosciences,Beijing 100083,China;School of Earth Sciences and Resources,China University of Geosciences,Beijinn 100083,China)

机构地区：[1]中国地质大学(北京)生物地质与环境地质国家重点实验室,北京100083 [2]中国地质大学(北京)地球科学与资源学院,北京100083

出　　处：《现代地质》2018年第6期1322-1328,共7页Geoscience

基　　金：国家自然科学基金面上项目(41472232)

摘　　要：地下水中三氯乙烯(TCE)严重威胁公众健康和环境安全,纳米零价铁原位注射技术可以还原降解TCE,但是应用中,纳米零价铁存在易氧化团聚而失活、迁移性差等问题。为此,利用天然高分子壳聚糖作包覆剂增强分散性和稳定性,镍作催化剂增强反应活性,成功制备获得壳聚糖包覆纳米铁镍双金属颗粒(CS-Fe-Ni)。沉降光谱实验表明包覆壳聚糖后纳米铁的分散稳定性得到增强,Zeta电位测试进一步证实颗粒表面负电荷增加,提高了静电排斥力,使得CSFe-Ni分散稳定性明显改善。柱迁移实验表明改性后的CS-Fe-Ni迁移能力得到提高。批实验表明CS-Fe-Ni能够高效降解TCE并能完全脱氯,研究结果为纳米铁原位注射技术的实际应用提供了理论基础和实验参考。Trichloroethylene(TCE)poses a serious threat to the public health and environmental safety.In-situ injection of nano zero-valent iron(nZVI)can be used to degrade TCE in groundwater.However,in applica tion,nZVI is easy to be oxidized and aggregated,resulting in loss of reactivity and poor mobility.Accordingly,in the present study,we used the natural polymer chitosan as a coating agent to increase the dispersion and stability,and loaded nickel as a catalyst to enhance the reactivity.A chitosan-coated nano-iron-nickel bimetallic particle(CS-I^e-Ni)was successfully prepared.The spectrum of CS-Fe-Ni sedimentation showed the dispersion and stability of nanoparticles were improved.The Zeta potential analysis indicated that the negative charge of particle surface increased due to coating chitosan,which promoted the electrostatic repulsion among the nanoparticles and the dispersion stability of CS-Fe-Ni.The column experiments showed the mobility of modified CS-Fe-Ni was largely improved.The batch experiments showed that CS-Fe-Ni can be able to highly degrade TCE for complete dechlorination.The results obtained from this study provided the theoretical and experimental basis for the application of nZVI in-situ remediation technology.

关 键 词：纳米零价铁 双金属 壳聚糖 迁移性能 三氯乙烯 

分 类 号：X142[环境科学与工程—环境科学]