微塑料对水生环境中有机锡光降解的影响。
Impacts of microplastics on organotins' photodegradation in aquatic environments.
机构信息
State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, China; John A. Reif, Jr. Department of Civil and Environmental Engineering, New Jersey Institute of Technology, Newark, NJ, USA.
State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, China.
出版信息
Environ Pollut. 2020 Dec;267:115686. doi: 10.1016/j.envpol.2020.115686. Epub 2020 Sep 18.
Microplastics are ubiquitous in natural waters and affect the environmental fate of hydrophobic organic micropollutants. This study evaluated the impacts of four microplastics, polypropylene (PP), polyethylene (PE), polystyrene (PS) and polymethyl methacrylate (PMMA), on the photodegradation of organotin compounds (OTCs) under UV irradiation (2.3 ± 0.1 W m). The experiments were performed by mixing PP, PE, PS or PMMA microparticles with tri-organotins in artificial seawater. The photodegradation of OTCs in microplastic suspensions was influenced by the absorptivity onto microplastics. The decomposition rate of tributyltin (TBT) in UV-irradiated PP suspensions was greater than trimethyltin (TMT) and triphenyltin (TPhT) (p < 0.01). The adsorption capacities of OTCs (e.g., TBT) on PP particle surfaces were significantly lower than those on PE surfaces (p < 0.05) but similar with those on PMMA due to the different surface areas, shapes, and surface hydrophobicity of microplastics. TBT degraded faster (9.1%) in PS than in PMMA suspension (11.2%) within 240 min, respectively. However, only less than 5.4% was photodegraded in PP suspension due to the light scattering or absorption of the large sized PP particles. This study provided new insight into the impacts of microplastics on photodegradation of micropollutants in natural waters.
微塑料在自然水体中普遍存在，并影响疏水性有机微污染物的环境归宿。本研究评估了四种微塑料，即聚丙烯（PP）、聚乙烯（PE）、聚苯乙烯（PS）和聚甲基丙烯酸甲酯（PMMA），对 UV 辐照下（2.3 ± 0.1 W m）有机锡化合物（OTCs）光降解的影响。实验通过将 PP、PE、PS 或 PMMA 微粒与三有机锡在人工海水中混合进行。微塑料悬浮液中 OTCs 的光降解受微塑料的吸光度影响。在 UV 辐照的 PP 悬浮液中，三丁基锡（TBT）的分解速率大于三甲基锡（TMT）和三苯基锡（TPhT）（p < 0.01）。OTC （如 TBT）在 PP 颗粒表面的吸附容量明显低于在 PE 表面的吸附容量（p < 0.05），但与 PMMA 表面的吸附容量相似，这是由于微塑料的表面积、形状和表面疏水性不同。在 240 分钟内，TBT 在 PS 中的降解速度（9.1%）快于在 PMMA 悬浮液中的降解速度（11.2%）。然而，由于大尺寸 PP 颗粒的光散射或吸收，只有不到 5.4%的 TBT 在 PP 悬浮液中被光降解。本研究为微塑料对自然水体中微污染物光降解的影响提供了新的见解。
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