郑小玉,张南,杨亚威,陶雨萌,吕培,花日茂.儿茶素、表儿茶素没食子酸酯对百菌清的光敏化降解[J].环境科学学报,2021,41(11):4554-4561
儿茶素、表儿茶素没食子酸酯对百菌清的光敏化降解
- Photodegradation of chlorothalonil by catechin and (-)-Epicatechin gallate in water
- 基金项目：国家自然科学基金（No.31672058）；国家重点研发计划项目（No.2016YFD0200205）
- 郑小玉
- 安徽农业大学, 资源与环境学院, 安徽省农产品质量安全重点实验室, 合肥 230036
- 张南
- 安徽农业大学, 资源与环境学院, 安徽省农产品质量安全重点实验室, 合肥 230036
- 杨亚威
- 安徽农业大学, 资源与环境学院, 安徽省农产品质量安全重点实验室, 合肥 230036
- 陶雨萌
- 安徽农业大学, 资源与环境学院, 安徽省农产品质量安全重点实验室, 合肥 230036
- 吕培
- 安徽农业大学, 资源与环境学院, 安徽省农产品质量安全重点实验室, 合肥 230036
- 花日茂
- 安徽农业大学, 资源与环境学院, 安徽省农产品质量安全重点实验室, 合肥 230036
- 摘要：为研究百菌清的光化学降解，研究了两种外源物质（天然提取物儿茶素和表儿茶素没食子酸酯）在不同条件下对百菌清的光化学降解作用效应和降解途径.结果表明：百菌清（1.88 μmol）水溶液中分别加入10物质的量比的儿茶素和表儿茶素没食子酸酯，在太阳光、紫外灯、高压汞灯照射下百菌清的光降解半衰期分别为12.4、15.4 min，10.7、12.8 min和6.2、2.3 min，儿茶素和表儿茶素没食子酸酯作用下的百菌清降解速率分别提高10.8~37.6和10.0~18.6倍.在稻田水、池塘水和田沟水3种自然水中，百菌清在3种光源下的降解半衰期分别为22.4~86.6、21.7~99.0和14.8~86.6 min；当添加10当量儿茶素时，百菌清的光降解速率分别提高3.0~5.9、1.5~3.0和1.8~2.9倍；当添加10当量表儿茶素没食子酸酯时，百菌清的光降解速率分别提高1.4~4.8、1.6~5.0和2.0~4.3倍.百菌清在儿茶素、表儿茶素没食子酸酯作用下主要降解产物为5-氯-1，3-二氰苯，避免了高毒降解产物4-羟基百菌清的产生；作用机理表现为发生光还原脱氯反应.研究结果可为百菌清使用过程中产生的水体污染修复提供技术参考.
- Abstract：To study the photodegradation of chlorothalonil, the effect of photolysis and degradation pathway of chlorothalonil with two natural compounds (catechin and (-)-epicatechin gallate) under different conditions were investigated. The results showed that, the half-lives (T1/2) of chlorothalonil were 12.4 and 15.4 min at the presence of catechin and (-)-epicatechin gallate under sunlight, 10.7 and 12.8 min under UV and 6.2 and 2.3 min under high-pressure mercury lamp (HPML) irradiation, respectively. The degradation rates increased 10.8~7.6 and 10.0~18.6 folds compared to the negative controls. In paddy water, pond water and ditch water, the degradation half-lives of chlorothalonil were 22.4~86.6, 21.7~99.0 and 14.8~86.6 min, respectively. After the 10 equivalents of catechin was added, the photodegradation rate of chlorothalonil increased 3.0~5.9, 1.5~3.0 and 1.8~2.9 folds, respectively. After the 10 equivalents of (-)-epicatechin gallate was added, the photodegradation rate of chlorothalonil increased 1.4~4.8, 1.6~5.0 and 2.0~4.3 folds, respectively. The main degradation products of chlorothalonil with catechin and (-)-epicatechin gallate was 5-chloro isophthalonitrile. This pathway avoided the production of 4-hydroxyl chlorothalonil, which is highly toxic. The photodegradation mechanism of chlorothalonil with catechin and (-)-epicatechin was reductive dechlorination reaction. The results could provide technical reference for the remediation of chlorothalonil in water.
