Department of Bioscience, Aarhus University, Aarhus 8000C, Denmark.
Department of Environment Science, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark.
Environ Pollut. 2017 Oct;229:362-370. doi: 10.1016/j.envpol.2017.06.017. Epub 2017 Jun 10.
Phytoremediation of realistic environmental concentrations (10 μg L) of the chiral pesticides tebuconazole and imazalil by Phragmites australis was investigated. This study focussed on removal dynamics, enantioselective mechanisms and transformation products (TPs) in both hydroponic growth solutions and plant tissues. For the first time, we documented uptake, translocation and metabolisation of these pesticides inside wetland plants, using enantioselective analysis. Tebuconazole and imazalil removal efficiencies from water reached 96.1% and 99.8%, respectively, by the end of the experiment (day 24). Removal from the solutions could be described by first-order removal kinetics with removal rate constants of 0.14 d for tebuconazole and 0.31 d for imazalil. Removal of the pesticides from the hydroponic solution, plant uptake, within plant translocation and degradation occurred simultaneously. Tebuconazole and imazalil concentrations inside Phragmites peaked at day 10 and 5d, respectively, and decreased thereafter. TPs of tebuconazole i.e., (5-(4-Chlorophenyl)-2,2-dimethyl-3-(1H-1,2,4-triazol-1-ylmethyl)-1,3-pentanediol and 5-(3-((1H-1,2,4-Triazol-1-yl)methyl)-3-hydroxy-4,4-dimethylpentyl)-2-chlorophenol) were quantified in solution, while the imazalil TPs (α-(2,4-Dichlorophenyl)-1H-imidazole-1-ethanol and 3-[1-(2,4-Dichlorophenyl)-2-(1H-imidazol-1-yl)ethoxy]-1,2-propanediol) were quantified in both solution and plant tissue. Pesticide uptake by Phragmites was positively correlated with evapotranspiration. Pesticide removal from the hydroponic solution was not enantioselective. However, tebuconazole was degraded enantioselectively both in the roots and shoots. Imazalil translocation and degradation inside Phragmites were also enantioselective: R-imazalil translocated faster than S-imazalil.
采用水培实验，研究了香蒲（Phragmites australis）对现实环境浓度（10μg/L）的手性农药戊唑醇和咪鲜胺的修复作用。本研究主要关注戊唑醇和咪鲜胺在水培溶液和植物组织中的去除动力学、对映选择性机制和转化产物（TPs）。本文首次采用对映体选择性分析，记录了这些农药在湿地植物体内的吸收、迁移和代谢。实验结束时（第 24 天），水相中戊唑醇和咪鲜胺的去除效率分别达到 96.1%和 99.8%。通过一级动力学方程可以很好地描述戊唑醇和咪鲜胺从溶液中的去除过程，其去除速率常数分别为 0.14 d 和 0.31 d。从水培溶液中去除农药、植物吸收、植物体内迁移和降解同时发生。戊唑醇和咪鲜胺在香蒲体内的浓度分别在第 10 天和第 5 天达到峰值，之后逐渐降低。在溶液中定量了戊唑醇的转化产物（(5-(4-氯苯基)-2,2-二甲基-3-(1H-1,2,4-三唑-1-基甲基)-1,3-戊二醇和 5-(3-((1H-1,2,4-三唑-1-基)甲基)-3-羟基-4,4-二甲基戊基)-2-氯苯酚），而咪鲜胺的转化产物（α-(2,4-二氯苯基)-1H-咪唑-1-乙醇和 3-[1-(2,4-二氯苯基)-2-(1H-咪唑-1-基)乙氧基]-1,2-丙二醇）则在溶液和植物组织中均有定量。香蒲对农药的吸收与蒸腾作用呈正相关。戊唑醇从水培溶液中的去除没有对映选择性，但在根和茎中戊唑醇都表现出对映体选择性降解。咪鲜胺在香蒲体内的迁移和降解也具有对映选择性：R-咪鲜胺的迁移速度快于 S-咪鲜胺。
