In this work, by using Mg(OH)₂ nanoplatelets as support material for nanoscale zerovalent iron (nZVI), nZVI@Mg(OH)₂ composite was prepared and found to have super high adsorption ability toward As(V) at environmentally relevant concentrations. It was revealed that the variation of corrosion products of nZVI in the presence of Mg(OH)₂ and Mg²⁺ is an important factor for increase in the adsorption ability toward As(V). X-ray diffraction (XRD) analysis indicated that the weakly basic condition induced by Mg(OH)₂ decreases the lepidocrocite (γ-FeOOH) and increases the magnetite/maghemite (Fe₃O₄/γ-Fe₂O₃) content in the corrosion products of nZVI, and the latter has better adsorption affinity to As(V). Moreover, extended X-ray absorption fine structure spectroscopy (EXAFS) indicated that the coordination between arsenic and iron minerals is influenced by dissolved Mg²⁺, leading to probable formation of magnesium ferrite (MgFe₂O₄) which has considerable adsorption affinity to As(V). This work provides an important reference not only for the design of pollution control materials but also for understanding arsenic immobilization in natural environments with ubiquitous Mg²⁺ ion.

中文翻译：

---

nZVI @ Mg（OH）₂纳米复合材料协同去除低浓度As（V）的机理

在这项工作中，通过使用Mg（OH）₂纳米片作为纳米级零价铁（nZVI）的载体材料，制备了nZVI @ Mg（OH）₂复合材料，发现其在环境相关浓度下对As（V）具有极高的吸附能力。 。揭示了在Mg（OH）₂和Mg ²⁺存在下nZVI腐蚀产物的变化是增加对As（V）吸附能力的重要因素。X射线衍射（XRD）分析表明，由镁引起的弱碱性条件（OH）₂降低了纤铁矿（γ-的FeOOH），并增加了磁铁矿/磁赤铁矿（铁₃ ö ₄ /γ-的Fe ₂ ö ₃nZVI的腐蚀产物中含有），而后者对As（V）具有更好的吸附亲和力。此外，扩展的X射线吸收精细结构光谱法（EXAFS）表明，砷和铁矿物质之间的配位受溶解的Mg ^2+的影响，导致可能形成铁酸镁（MgFe ₂ O ₄），该铁素体对As具有相当大的吸附亲和力。 （V）。这项工作不仅为污染控制材料的设计提供了重要参考，而且对于理解随处可见的Mg ²⁺离子将砷固定在自然环境中也提供了重要的参考。