School of Ecology and Environment, Beijing Technology and Business University, Beijing 100048, China.
Beijing Advanced Innovation Centre for Food Nutrition and Human Health, Department of Pesticide, China Agricultural University, Beijing 100193, China.
Ecotoxicol Environ Saf. 2021 Aug;219:112236. doi: 10.1016/j.ecoenv.2021.112236. Epub 2021 May 12.
After application, pesticides remained in the field may contaminate water resources through surface runoff and leaching, posing a threat to aquatic ecosystem. In the current study, the accumulation, translocation, distribution and removal of four triazine pesticides (simazine, atrazine, terbuthylazine and metribuzin) by free floating aquatic plant Eichhornia crassipes (E. crassipes) in water-sediment microcosm were investigated and the removal mechanisms were explored. E. crassipes was exposed to an initial concentration of 50 μg·L and the pesticide levels in water, sediment, roots and shoots of E. crassipes were monitored during 30 days. The results demonstrated that E. crassipes was capable of accumulating triazine pesticides with the bio-concentration factor (BCF) ranging from 0.8 to 18.4. Triazine pesticides were mainly stored in roots, and root accumulation and translocation amount depend on the hydrophobicity of the pesticides. The removal of the pesticides in water were significantly accelerated by the presence of E. crassipes, with the removal efficiency ranging from 66% to 79% after 30 days of treatment. Though phytoaccumulation only constituted 2-18% of the total spiked pesticides in the microcosm, E. crassipes played a vital role in removing simazine, atrazine and metribuzin. However, microbial degradation in sediment was the main pathway for the removal of terbuthylazine in the microcosm. This study demonstrated the potential application of E. crassipes to accelerate removal of contaminants from aquatic environment.
施用到田间的农药可能会通过地表径流和淋溶污染水资源，对水生生态系统构成威胁。在本研究中，通过水-沉积物微宇宙实验，研究了自由漂浮水生植物凤眼莲（Eichhornia crassipes）对四种三嗪类农药（西玛津、莠去津、特丁津和二甲戊灵）的积累、迁移、分布和去除，并探讨了去除机制。凤眼莲暴露于初始浓度为 50μg·L 的农药中，在 30 天内监测水中、沉积物中、凤眼莲的根和茎叶中的农药水平。结果表明，凤眼莲能够积累三嗪类农药，其生物浓缩因子（BCF）范围为 0.8 至 18.4。三嗪类农药主要储存在根部，根的积累和迁移量取决于农药的疏水性。凤眼莲的存在显著加速了水中农药的去除，经过 30 天的处理，去除效率范围为 66%至 79%。尽管植物累积仅占微宇宙中总添加农药的 2%至 18%，但凤眼莲在去除西玛津、莠去津和二甲戊灵方面发挥了重要作用。然而，在微宇宙中，沉积物中的微生物降解是特丁津去除的主要途径。本研究表明，凤眼莲具有加速水生环境中污染物去除的潜力。
