SiO2-coated zero-valent iron nanocomposites for aqueous nitrobenzene reduction in groundwater: Performance, reduction mechanism and the effects of hydrogeochemical constituents
SiO2-coated zero-valent iron nanocomposites for aqueous nitrobenzene reduction in groundwater: Performance, reduction mechanism and the effects of hydrogeochemical constituents
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SiO2 涂层零价铁纳米复合材料用于还原地下水中硝基苯：性能、还原机理和水文地球化学成分的影响
DOI：
10.1016/j.colsurfa.2018.08.081
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发表时间：
2018-12
期刊：
影响因子：
--
通讯作者：
Yue Wu
中科院分区：
文献类型：
--
作者：
Haojie Lu;Jun Dong;Mengyue Zhang;Wenhua Hu;Chunyu Wen;Chaoge Yang;Yue Wu
纳米零价铁（nZVI）表面改性为硝基苯（NB）污染地下水的原位修复提供了一条有效途径。但也存在二次污染和生态毒性等问题，而且改性后的nZVI活性也易受地下水水文地球化学成分（如pH、常见离子）的影响。SiO2涂层技术是减少二次污染、增强生物相容性和改善nZVI在污染降解过程中对周围环境变化不敏感性的一种很有前途的方法。制备并表征了SiO2包覆nZVI复合材料，研究了SiO2包覆nZVI复合材料还原NB的微观机理和性能，考察了地下水水文地球化学成分（pH、常见离子）对NB还原的影响。结果表明，SiO2包覆技术提供了可渗透的网状结构，有利于NB水溶液与内部nZVI接触反应，反应过程中检测到了亚硝基苯和氧化偶氮苯作为中间产物，NB水溶液完全转化为苯胺（AN）的最大降解量约为366.3 mg/g，是裸nZVI的3.75倍。在碱性（pH = 5 ~ 7）地下水环境中，合成的复合物对NB转化为AN的反应活性没有明显的抑制作用; Na+、K+、Cl−、NO3-和SO 42-对合成的复合物的活性没有影响; Ca 2+和Mg 2+对NB转化为AN有抑制作用，HCO 3-对NB转化为AN有促进作用。总体而言，本研究证明了SiO2包覆nZVI复合材料的优越性，并为未来在地下水修复中的应用提供了有用的信息。
Nanoscale zero-valent iron (nZVI) surface modification provides an effective way for in-situ remediation of nitrobenzene (NB) contaminated groundwater. However, it may bring some problems such as secondary pollution and ecotoxicity; moreover, the activity of modified nZVI was also vulnerable to the hydrogeochemical constituents of groundwater (e.g. pH, common ions). SiO2-coating technology is a promising approach to reduce secondary pollution, enhance the biocompatibility and improve the insensitivity of nZVI to the changes of the surrounding environment during contamination degradation process. In this study, the SiO2-coated nZVI composites were prepared and characterized; the microscopic mechanism and performance of NB reduction by SiO2-coated nZVI composites were studied; the effects of hydrogeochemical constituents of groundwater (e.g. pH, common ions) on NB reduction were investigated. The results indicated that SiO2-coating technology provided permeable mesh structure, which could facilitate aqueous NB to contact and react with the internal nZVI; in the reaction process, nitrosobenzene and azoxybenzene were detected as the intermediate and the maximum degradation capacity for thoroughly converting aqueous NB to aniline (AN) was approximately 366.3 mg/g, which was 3.75 times higher than that of bare nZVI. Furthermore, the synthesized composite showed no significantly reactivity restriction in the alkaline (pH, 5∼7) groundwater environment; Na+, K+, Cl−, NO3- and SO42-had no effect on the activity of the synthesized composite; Ca2+and Mg2+exhibited an inhibitory effect and HCO3- had an enhancement effect on the conversion of NB to AN. Overall, this study demonstrated the superiority of SiO2-coated nZVI composites and provided useful information for the future application in groundwater remediation.
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影响因子：
15.1
作者：
Cai, Zhengqing;Fu, Jie;Zhao, Dongye
通讯作者：
Zhao, Dongye
DOI：
10.1016/j.scitotenv.2018.01.115
发表时间：
2018-06
期刊：
The Science of the total environment
影响因子：
--
作者：
Jia Xin;Fenglin Tang;J. Yan;Chenghong La;Xilai Zheng;W. Liu
通讯作者：
Jia Xin;Fenglin Tang;J. Yan;Chenghong La;Xilai Zheng;W. Liu
影响因子：
11.4
作者：
Agrawal, A;Tratnyek, PG
通讯作者：
Tratnyek, PG
影响因子：
6.7
作者：
Yamashita, Toru;Hayes, Peter
通讯作者：
Hayes, Peter
影响因子：
5.3
作者：
Miguel Rodriguez;V. Timokhin;F. Michl;S. Contreras;J. Giménez;S. Esplugas
通讯作者：
Miguel Rodriguez;V. Timokhin;F. Michl;S. Contreras;J. Giménez;S. Esplugas