Research Institute of Environment, Agriculture and Fisheries, Osaka Prefecture, Habikino, Osaka 583-0862, Japan.
Research Institute of Environment, Agriculture and Fisheries, Osaka Prefecture, Habikino, Osaka 583-0862, Japan.
Mar Pollut Bull. 2021 Aug;169:112561. doi: 10.1016/j.marpolbul.2021.112561. Epub 2021 Jun 2.
Contaminants adsorbed on microplastics (MPs) are a potential risk to aquatic environments. Several studies have demonstrated that polycyclic aromatic hydrocarbons (PAHs), which adsorb on MPs, can be photolyzed in aqueous solutions. We investigated photolysis of PAHs on MPs under sunlight conditions to estimate their environmental fate for the first time. The PAHs (25 ng each) were added to polyethylene powder, which was used as the MP sample. The MP sample was agitated in water with sunlight irradiation; thereafter, the concentration of the PAHs on the MP sample was determined by high-pressure liquid chromatography with a fluorescence detector. The half-life values of the PAHs were estimated between 3.4 × 10 (pyrene) and 3.2 × 10 min (benz[j]fluoranthene). These values are 0.5 (fluoranthene) to 25 (benzo[a]pyrene) times larger than those in the aqueous phase. Additionally, the degradation of PAHs by OH radicals produced by the photolysis of nitrate was observed.
微塑料（MPs）上吸附的污染物对水生环境构成潜在风险。多项研究表明，多环芳烃（PAHs）可在水溶液中光解，这些物质吸附在 MPs 上。我们首次在阳光条件下研究了 MPs 上 PAHs 的光解，以评估它们的环境归宿。将 25ng 每种 PAHs 添加到用作 MPs 样品的聚乙烯粉末中。将 MP 样品在水中搅拌并进行阳光照射；之后，通过带有荧光检测器的高压液相色谱法测定 MP 样品上 PAHs 的浓度。PAHs 的半衰期值估计在 3.4×10（苝）至 3.2×10 分钟（苯并[j]荧蒽）之间。这些值是水相中的 0.5（荧蒽）至 25（苯并[a]芘）倍。此外，还观察到由硝酸盐光解产生的 OH 自由基对 PAHs 的降解。
