Trichloroethene (TCE) degradation by Fe(III)-activated calcium peroxide (CP) in the presence of citric acid (CA) in aqueous solution was investigated. The results demonstrated that the presence of CA enhanced TCE degradation significantly by increasing the concentration of soluble Fe(III) and promoting H2O2 generation. The generation of HO• and O2-• in both the CP/Fe(III) and CP/Fe(III)/CA systems was confirmed with chemical probes. The results of radical scavenging tests showed that TCE degradation was due predominantly o direct oxidation by HO•, while O2-• strengthened the generation of HO• by promoting Fe(III) transformation in the CP/Fe(III)/CA system. Acidic pH conditions were favorable for TCE degradation, and the TCE degradation rate decreased with increasing pH. The presence of Cl-, HCO3-, and humic acid (HA) inhibited TCE degradation to different extents for the CP/Fe(III)/CA system. Analysis of Cl- production suggested that TCE degradation in the CP/Fe(III)/CA system occurred through a dechlorination process. In summary, this study provided detailed information for the application of CA-enhanced Fe(III)-activated calcium peroxide for treating TCE contaminated groundwater.

中文翻译：

---

在柠檬酸存在下，用Fe（III）活化的过氧化钙增强了三氯乙烯的降解。

研究了在水溶液中柠檬酸（CA）存在下，Fe（III）活化的过氧化钙（CP）对三氯乙烯（TCE）的降解。结果表明，CA的存在通过增加可溶性Fe（III）的浓度并促进H2O2的产生而显着提高了TCE的降解。用化学探针证实了CP / Fe（III）和CP / Fe（III）/ CA系统中HO•和O2-•的生成。自由基清除测试的结果表明，TCE降解主要是由于HO•直接氧化而引起的，而O2-•通过促进CP / Fe（III）/ CA系统中的Fe（III）转化而增强了HO•的生成。酸性pH条件有利于TCE降解，TCE降解速率随pH的升高而降低。Cl-，HCO3-，腐殖酸（HA）对CP / Fe（III）/ CA系统的TCE降解具有不同程度的抑制作用。对氯生成的分析表明，CP / Fe（III）/ CA系统中的三氯乙烯降解是通过脱氯过程发生的。总而言之，这项研究为CA增强的Fe（III）活化的过氧化钙在处理受TCE污染的地下水中的应用提供了详细的信息。