零价铁广泛应用于受污染地下水修复和工业废水处理中，但钝化问题已成为推动零价铁技术应用的重要障碍，如何提高已钝化零价铁的反应活性已成为研究的焦点，本课题提出利用弱磁场来实现已钝化零价铁的活化。模拟零价铁在地下水修复和工业废水处理中的实际反应过程，制备含有不同性质、不同钝化膜含量的已钝化零价铁并进行系统地表征，以Se(IV)为目标污染物，建立弱磁场对已钝化零价铁除Se(IV)过程的加速程度与磁场强度、钝化膜性质和含量之间的关系；设计连续流反应器，利用永磁铁提供的磁场实现对已钝化零价铁连续除Se(IV)过程的加速；解析弱磁场对已钝化零价铁除Se(IV)过程中Se(IV)的价态转化、去除机理的影响；根据电化学实验、磁学测量、磁学软件的计算结果和较宏观尺度实验的验证，明确弱磁场在加速已钝化零价铁除Se(IV)过程中的作用机制。课题有望为已钝化零价铁提供一种有效的活化技术，破解零价铁应用的技术难题。

Passivation of zero valent iron (ZVI) has become an obstacle of applying ZVI for contaminants removal either in permeable reactive barrier or in industrial wastewater treatment. Thus, improving the reactivity of the passivated ZVI is of significance. Weak magnetic field (WMF) is proposed to accelerate Se(IV) removal by passivated ZVI and to rejuvenate the reactivity of passivated ZVI in this study. Various passivated ZVI samples with passive layers of different constituents and contents will be synthesized and the synthesized passivated ZVI samples will be characterized carefully with various techniques. A reactor with applied weak magnetic field (WMF) will be constructed and the batch experiments will be conducted in this reactor. The relationship among the WMF intensity, the properties of passive layer, and the WMF-induced enhancement in Se(IV) removal by passivated ZVI will be elucidated. A continuous reactor with permanent magnets to provide WMF will be designed and the influence of WMF on Se(IV) removal by passivated ZVI in a continuous process will be determined. The mechanisms of Se(IV) removal by passivated ZVI in the presence or absence of WMF will be determined. Electrochemical experiments will be performed to determine the rate-limiting step of Se(IV) removal by aged ZVI and the influence of WMF on the rat-limiting step. Finite element software will be employed to calculate the distribution and gradient of induced magnetic field by passivated ZVI in an applied WMF. Experiments with iron wire will be designed to support the results of theoretical calculation and thus the role of WMF in Se(IV) removal by passivated ZVI will be clarified. This project will not only offer a brand-new and environmental-friendly method of activating passivated ZVI but also set up the foundation of water treatment magneto-chemistry.