Journal of Hazardous Materials：nZVI/BC复合材料去除土壤和水中污...

扬州大学环境学院王小治教授团队与高丽大学生物炭研究中心Yong Sik Ok团队综述了nZVI/BC复合材料的制备、影响要素及其与污染物的作用机制。相关成果发表于Journal of Hazardous Materials（IF=7.650）。

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Highlights

·Aggregation and passivation of nZVI can be alleviated by surfactants and doping methods.

·BC hinders corrosion and improves the dispersion and electron transfer of nZVI.

·Properties of nZVI depend on those of the BC, feedstock and pyrogenic temperature.

·BC enhances electron transfer from nZVI to the contaminants due to the presence of quinone and graphene moieties.

·nZVI/BC shows strong ability to remove HMs, nitrates, and organic contaminants in soil and water.

Abstract

The promising characteristics of nanoscale zero-valent iron (nZVI) have not been fully exploited owing to intrinsic limitations. Carbon-enriched biochar (BC) has been widely used to overcome the limitations of nZVI and improve its reaction with environmental pollutants. This work reviews the preparation of nZVI/BC nanocomposites; the effects of BC as a supporting matrix on the nZVI crystallite size, dispersion, and oxidation and electron transfer capacity; and its interaction mechanisms with contaminants. The literature review suggests that the properties and preparation conditions of BC (e.g., pore structure, functional groups, feedstock composition, and pyrogenic temperature) play important roles in the manipulation of nZVI properties. This review discusses the interactions of nZVI/BC composites with heavy metals, nitrates, and organic compounds in soil and water. Overall, BC contributes to the removal of contaminants because it can attenuate contaminants on the surface of nZVI/BC; it also enhances electron transfer from nZVI to target contaminants owing to its good electrical conductivity and improves the crystallite size and dispersion of nZVI. This review is intended to provide insights into methods of optimizing nZVI/BC synthesis and maximizing the efficiency of nZVI in environmental cleanup.

纳米零价铁（nZVI）具有固有的局限性，因此尚未得到充分的开发利用。目前，富碳生物炭（BC）被广泛用于克服nZVI的局限性，改善其与环境污染物的反应。本文综述了nZVI/BC纳米复合材料的制备方法；BC作为支撑基体对nZVI晶体尺寸、分散、氧化和电子转移能力的影响及其与污染物的相互作用机制。文献综述表明，BC的性质和制备条件（如孔隙结构、官能团、制备原料组成、烧制温度）对nZVI性质的控制起着重要作用。本文还讨论了了nZVI/BC复合材料与土壤和水中的重金属、硝酸盐和有机化合物的相互作用。结论表明，BC可以弱化nZVI/BC表面的污染物，有助于去除污染物；由于其良好的导电性，它还增强了nZVI向目标污染物的电子转移，并改善了nZVI的晶体尺寸和分散性。本篇综述旨在为优化nZVI/BC合成和最大限度地提高nZVI在环境净化中的效率的方法提供依据。