Trichloroethene degradation by nanoscale CaO2 activated with Fe(II)/FeS: The role of FeS and the synergistic activation mechanism of Fe(II)/FeS
Trichloroethene degradation by nanoscale CaO2 activated with Fe(II)/FeS: The role of FeS and the synergistic activation mechanism of Fe(II)/FeS
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DOI：
10.1016/j.cej.2020.124830
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发表时间：
2020-08
影响因子：
15.1
通讯作者：
Yongzhen Sun;M. Danish;Meesam Ali;A. Shan;Ming Li;Yanchen Lyu;Z. Qiu;Q. Sui;Xueke Zang
中科院分区：
文献类型：
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作者：
Yongzhen Sun;M. Danish;Meesam Ali;A. Shan;Ming Li;Yanchen Lyu;Z. Qiu;Q. Sui;Xueke Zang
在纳米过氧化钙（nCP）环境中，FeS的加入显著提高了三氯乙烯（TCE）的降解性能，并通过与nCP/Fe（II）和nCP/FeS体系的比较证实了nCP/Fe（II）/FeS体系中HO自由基点生成的增强。FeS在nCP/Fe（II）/FeS体系中的作用表明，一方面FeS活化了nCP，在催化剂表面产生了大量的活性氧自由基（ROS），另一方面FeS的还原性使Fe（III）还原为Fe（II），促进了TCE的降解.探针和清除剂测试结果表明，主要的ROS是HO自由基点而不是O2−自由基点。当nCP/Fe（II）/FeS/TCE的摩尔比为2/2/4/1时，TCE的降解率达91.5%以上，其中TCE的脱氯率达95.5%以上。研究了表面活性剂对三氯乙烯降解的影响。相反，进一步的研究发现，BTEX的去除与FeS的添加抑制。本研究揭示了硫化亚铁的良好作用和基本的增效机理。此外，通过对实际地下水中TCE的降解，证实了nCP/Fe（II）/FeS技术在ISCO实践中TCE污染地下水修复中具有很大的优势和潜力。
The performance of trichloroethene (TCE) degradation was significantly improved with the addition of FeS in nanoscale calcium peroxide (nCP) environment and the enhancement of HOradical dot generation in nCP/Fe(II)/FeS system was confirmed by comparison with nCP/Fe(II) and nCP/FeS systems. The role of FeS in nCP/Fe(II)/FeS system demonstrated that the majority of reactive oxygen radicals (ROSs) was generated on the catalyst surface due to the heterogeneous reaction through FeS activated nCP in one hand, and the reductive FeS could promote TCE degradation by regenerating Fe(II) from Fe(III) in the other hand. The probe as well as scavenger test results suggested that the major ROSs was HOradical dot rather than O2−radical dot. Over 91.5% TCE could be degraded at the molar ratio of 2/2/4/1 of nCP/Fe(II)/FeS/TCE, in which more than 95.5% TCE was dechlorinated. The effect of surfactants on TCE degradation was evaluated. In contrast, further investigation found that BTEX removal was inhibited with the addition of FeS. In conclusion, this study revealed the well function and fundamental synergistic mechanism of FeS. Moreover, the degradation of TCE in actual groundwater confirmed that nCP/Fe(II)/FeS technique has a great advantage and potential in TCE contaminated groundwater remediation in ISCO practice.