Degradation of trichloroethylene in aqueous solution by sodium percarbonate activated with Fe(II)-citric acid complex in the presence of surfactant Tween-80.
Degradation of trichloroethylene in aqueous solution by sodium percarbonate activated with Fe(II)-citric acid complex in the presence of surfactant Tween-80.
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DOI：
10.1016/j.chemosphere.2020.127223
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发表时间：
2020-05
期刊：
影响因子：
8.8
通讯作者：
Yanchen Lyu;Shuguang Lyu;P. Tang;Wenchao Jiang;Yongzhen Sun;Ming Li;Q. Sui
中科院分区：
文献类型：
--
作者：
Yanchen Lyu;Shuguang Lyu;P. Tang;Wenchao Jiang;Yongzhen Sun;Ming Li;Q. Sui
研究了在非离子表面活性剂Tween-80存在下，柠檬酸（CA）螯合Fe（II）活化的过碳酸钠（SPC）对三氯乙烯（TCE）的降解性能。CA的加入成功地阻止了铁的沉淀，促进了TCE的降解。而Tween-80对TCE降解有抑制作用，主要是由于Tween-80与TCE之间的羟基竞争。结果表明，当SPC/Fe（II）/CA/TCE摩尔比为3/4/2/1时，TCE在15 min内降解率可达87.2%。自由基探针测试证实，在SPC/Fe（II）/CA系统中产生了O2− OH和O2 − OH。自由基清除实验表明，SPC/Fe（II）/CA体系中TCE的降解主要是由β-OH引起的，而O2− β仅部分参与TCE的降解.此外，TCE去除抑制与初始溶液的pH值从3.0到9.0的上升。实际的地下水（含吐温-80）的测试证实，93.2%的TCE降解可以实现SPC/Fe（II）/CA/TCE的摩尔比为30/40/10/1，并强烈表明，SPC/Fe（II）/CA工艺具有潜在的原位处理TCE污染的地下水在表面活性剂吐温-80的存在下。综上所述，CA的加入可显著提高TCE在Tween-80存在下Fe（II）活化SPC体系的降解效果，这一发现为表面活性剂增溶处理后污染场地地下水中氯代有机污染物的去除提供了一个创新方向。
The degradation performance of trichloroethylene (TCE) by sodium percarbonate (SPC) activated with citric acid (CA) chelated Fe(II) in the presence of nonionic surfactant Tween-80 was investigated. The addition of CA successfully prevented the precipitation of iron and facilitated TCE degradation. However, Tween-80 had an inhibitory effect on TCE degradation mainly due to the competition of∗OH between Tween-80 and TCE. The effect of SPC and Fe(II) dosage on TCE degradation was also explored and the results displayed that 87.2% of TCE could be degraded in 15 min at the SPC/Fe(II)/CA/TCE molar ratio of 3/4/2/1. Free radical probe tests confirmed that both O2−∗and∗OH were generated in the SPC/Fe(II)/CA system. Free radical scavenging tests implied that the degradation of TCE in the SPC/Fe(II)/CA system was mainly attributed to ∗OH, while O2−∗was only partially involved in the degradation of TCE. In addition, TCE removal was suppressed with the raising of the initial solution pH from 3.0 to 9.0. The actual groundwater (containing Tween-80) tests confirmed that 93.2% of TCE degradation could be achieved at the SPC/Fe(II)/CA/TCE molar ratio of 30/40/10/1 and strongly demonstrated that the SPC/Fe(II)/CA process has potential for the in situ treatment of TCE contaminated groundwater in the presence of surfactant Tween-80. In conclusion, TCE degradation by Fe(II) activated SPC system in the presence of Tween-80 can be significantly enhanced with the addition of CA, and this finding offers an innovative direction for removing chlorinated organic contaminants from groundwater in contaminated site after surfactant solubilization treatment.