Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China.
Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China.
J Environ Sci (China). 2022 Nov;121:199-210. doi: 10.1016/j.jes.2022.02.001. Epub 2022 Feb 11.
Chiral pesticides account for 30% of pesticides. Pesticides are inevitably leached into the groundwater by runoff. At the watershed level, the distribution characteristics of enantiomers in sediments collected from the river network of an agricultural area near the middle and lower reaches of the Yangtze River were tested, and their potential correlations with the physicochemical properties and microbial communities of the sediments were analyzed. The sediment pollution was serious at sites 8 and 9, with their pollution source possibly being agricultural or industrial sewage. Moreover, there were higher cumulative contents of pesticide residues at sites 4, 8, and 9. Specifically, Cycloxaprid was the most detected chiral pesticide in the study area, followed by Dinotefuran and Diclofop-methyl. Additionally, Ethiprole and Difenoconazole had strong enantioselectivity in the study area. Interestingly, the enantiomers of some chiral pesticides, such as Tebuconazole, had completely different distributions at different sites. Pearson correlation analysis showed that sediment catalase and microbial biomass carbon were important factors for enantioselectivity of chiral pesticides. The effect of sediment physicochemical properties on enantioselective distribution was achieved by influencing the microorganisms in the sediment. Furthermore, the enantioselective distribution of Tebuconazole was closely related to the genus Arenimonas. Overall, the enantioselective distribution of most of the chiral pesticides was positively correlated with the prokaryotic microbial community. This study provides empirical support for agricultural non-point source pollution caused by chiral pesticides, and also lays a research foundation for exploring the factors that affect the fate of chiral pesticides in the environment.
手性农药占农药的 30%。农药不可避免地会随地表径流渗入地下水。在流域尺度上，测试了长江中下游地区农业区河网沉积物中收集到的手性农药对映体的分布特征，并分析了它们与沉积物理化性质和微生物群落的潜在相关性。8 号和 9 号位点的沉积物污染严重，污染源可能是农业或工业污水。此外，4 号、8 号和 9 号位点的农药残留累积含量较高。具体来说，在研究区域中，最检测到的手性农药是 Cycloxaprid，其次是 Dinotefuran 和 Diclofop-methyl。此外，Ethiprole 和 Difenoconazole 在研究区域具有很强的对映选择性。有趣的是，一些手性农药的对映体，如 Tebuconazole，在不同地点的分布完全不同。Pearson 相关分析表明，沉积物过氧化氢酶和微生物生物量碳是手性农药对映选择性的重要因素。沉积物理化性质通过影响沉积物中的微生物对映选择性分布的影响。此外，Tebuconazole 的对映选择性分布与 Arenimonas 属密切相关。总体而言，大多数手性农药的对映选择性分布与原核微生物群落呈正相关。本研究为手性农药引起的农业非点源污染提供了经验支持，也为探索影响环境中手性农药命运的因素奠定了研究基础。
