Weak magnetic field enables high selectivity of zerovalent iron toward metalloid oxyanions under aerobic conditions
Weak magnetic field enables high selectivity of zerovalent iron toward metalloid oxyanions under aerobic conditions
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弱磁场使得零价铁在有氧条件下对准金属氧阴离子具有高选择性
DOI：
10.1016/j.jhazmat.2020.123330
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发表时间：
2020
影响因子：
13.6
通讯作者：
Guan Xiaohong
中科院分区：
文献类型：
--
作者：
Li Jinxiang;Sun Yuankui;Zhang Xueying;Guan Xiaohong
对于零价铁 (ZVI) 的水处理/修复，特别值得关注的是其对污染物相对于天然非目标（例如 O 2 和 H 2 O/H+）的选择性。因此，在有氧条件下，深入研究了弱磁场（WMF）对ZVI对准金属氧阴离子（即As（III）、As（V）、Sb（III）、Sb（V）、Se（IV）和Se（VI））选择性的影响。这项研究表明，尽管在反应平衡时，有和没有 WMF 的 ZVI 的电子利用率 (EU) 几乎相同，但应用 WMF 可以将 ZVI 对类金属氧阴离子的比去除能力 (SRC) 从 1.8–19.0 mg/g Fe 提高到 12.6–85.3 mg/g Fe。特别是，具有 WMF 的 ZVI 还原 Se (IV)/Se (VI) 的电子效率 (EE) 比不具有 WMF 的 ZVI 高 3.7 至 14.1 倍。由于 WMF 诱导的磁梯度力 (F Δ B) 可以导出 Fe 2+ 和准金属氧阴离子的运动，因此随后准金属氧阴离子与原位生成的铁氧化物的结合也可以同步介导，从而导致 ZVI 的 SRC 增强（也可以通过 ZVI 还原 Se (IV) 和 Se (VI) 的 EE）。总的来说，我们的研究结果证明，WMF 应该是一种有前途的方法，可以提高 ZVI 在有氧条件下水净化的选择性。
For water treatment/remediation by zerovalent iron (ZVI), of particular concern is its selectivity toward contaminants over natural non-targets (eg, O 2 and H 2 O/H+). Hence, the effects of weak magnetic field (WMF) on the selectivity of ZVI toward metalloid oxyanions (ie, As (III), As (V), Sb (III), Sb (V), Se (IV) and Se (VI)) were in-depth investigated under aerobic conditions. This study unraveled that, despite the electron utilization (EU) of ZVI with and without WMF were almost identical at reaction equilibrium, the application of a WMF could enhance the specific removal capacity (SRC) of ZVI toward metalloid oxyanions from 1.8–19.0 mg/g Fe to 12.6–85.3 mg/g Fe. Particularly, the electron efficiency (EE) of ZVI with WMF for reduction of Se (IV)/Se (VI) were 3.7-to 14.1-fold greater than that without WMF. Since the WMF-induced magnetic gradient force (F Δ B) can derive the movement of both Fe 2+ and metalloid oxyanions, the subsequent incorporation of metalloid oxyanions with in-situ generated iron oxides can also been mediated synchronously and thus leading to an enhanced SRC of ZVI (also EE for Se (IV) and Se (VI) reduction by ZVI). In general, our findings prove that WMF should be a promising method to promote the selectivity of ZVI for water decontamination under aerobic conditions.