紫外光照对聚氯乙烯微塑料吸附及降解氟虫腈的影响
- The Impact of Ultraviolet Light on the Adsorption and Degradation of Fipronil by Polyvinyl Chloride Microplastics
- 基金项目：广东省基础与应用基础研究基金 (2023A1515030203, 2024A1515011905),南方海洋科学与工程广东实验室 (珠海) 创新群体项目 (SML2021SP208)
- 摘要：微塑料在环境中和大量有机污染物广泛共存,并改变有机污染物的环境行为和生物毒性。本文分别以聚氯乙烯(PVC)微塑料(150~355 μm)和氟虫腈作为微塑料和有机污染物的代表,研究了原始和老化微塑料对氟虫腈的吸附和转化作用。老化过程显著改变了微塑料的物理化学性质,并且使微塑料对氟虫腈的吸附量从2582 ng.g-1增加至2903 ng.g-1。除吸附作用外,微塑料还能够促进氟虫腈在其表面发生氧化转化,生成氟虫腈砜,其在原始和老化微塑料表面的含量分别为285 ng.g-1和367 ng.g-1。在紫外光照条件下,氟虫腈在微塑料表面的转化过程被显著促进,在原始和老化微塑料表面生成的氟虫腈砜含量分别为1578 ng.g-1和2013 ng.g-1。鉴于氟虫腈砜的生物毒性可能高于母体化合物,因此微塑料对氟虫腈的转化效应会显著改变氟虫腈的水生态毒性和风险。
- Abstract：Microplastics (MPs) widely coexist with numerous organic pollutants in the environment, altering the environmental behavior and ecotoxicity of these pollutants. In this study, polyvinyl chloride (PVC) MPs (150~355 μm) and fipronil were used as representatives of microplastics and organic pollutants, respectively, to investigate the adsorption and transformation of fipronil by pristine and aged MPs. The aging process significantly altered the physicochemical properties of MPs and increased their adsorption capacity against fipronil from 2582 ng·g-1 to 2903 ng·g-1. In addition to adsorption, MPs were found to promote the oxidative transformation of fipronil on MP surfaces, leading to formation of fipronil sulfone, with concentrations of 285 ng·g-1 and 367 ng·g-1 on pristine and aged MPs, respectively. Under ultraviolet (UV) conditions, the transformation of fipronil on the MP surfaces was significantly enhanced, with fipronil sulfone concentrations reaching 1578 ng·g-1 and 2013 ng·g-1 on pristine and aged MPs, respectively. Given that the ecotoxicity of fipronil sulfone may be higher than that of the parent compound, the transformation of fipronil by MPs could substantially alter its aquatic ecotoxicity and environmental risk.
