本课题针对零价铁易钝化导致反应活性差的问题，提出将零价铁表面覆盖导电子能力强的铁硫化物进行改性，并利用绿色环保的磁技术进行强化来提高其反应活性。申请人前期研究中发现硫化改性可以明显加速零价铁的腐蚀速率，且磁场对该过程有一定的强化作用，但其动力学影响规律和加速机理尚不清晰。因此本项目拟选择毒性较强的亚硒酸盐为目标污染物，制备一系列不同硫铁摩尔比的改性零价铁，在磁场的作用下研究其快速去除亚硒酸盐的动力学过程，对操作条件进行优化；同时设计连续流实验装置，实现磁场强化硫化改性零价铁连续去除亚硒酸盐的过程；利用EXAFS/XPS/XRD等技术探明表面硫化改性加速零价铁去除污染物的关键结构特性，明晰该体系去除亚硒酸盐过程中亚硒酸盐的去除机理及腐蚀产物的生成和演变规律。本项目预期成果将为零价铁的活化提供新的方向，进而推动磁场强化零价铁体系在水处理及环境修复领域的应用。

Zero valent iron (ZVI) has been shown to remove a wide variety of contaminants from water. However, passivation has become an obstacle of applying ZVI for contaminants removal either in permeable reactive barrier or in industrial wastewater treatment. In order to solve this problem, sulfide modified Zero valent iron (S-ZVI) synergy with magnetic field were proposed to improve the reactivity of ZVI. In our previous study, it was found that sulfide modified zero valent iron increased the removal rate of selenite than ZVI, and magnetic field accelerated this process further. However, the kinetics and mechanisms of sulfide modified zero-valent iron remove selenite in the presence of magnetic field were still unexplored. Therefore, selenite (Se(IV)) will be selected as the model pollutant in this project. A series of sulfide modified zero valent iron was synthesized by changing the S and Fe mole ratio. The performance of this material for Se(IV) removal was tested by comparison with pure ZVI with or without the presence of magnetic field, and the mechanisms are elucidated based on SEM, XRD, XPS,EXAFS and experimental results. This study will not only offer a simple and effective method of activating ZVI but also intrigue the broader applications of ZVI assistance with magnetic field on field-scale remediation.