Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 511443, China.
Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 511443, China.
J Hazard Mater. 2022 Jun 5;431:128523. doi: 10.1016/j.jhazmat.2022.128523. Epub 2022 Feb 24.
Excessive use of plastics leads to the ubiquity of plastic waste in the environment. Weathering can cause changes in the properties of plastics and lead to the release of various chemicals especially the volatile organic compounds (VOCs). Possible photodegradation pathway of polystyrene (PS) microplastics (MPs) was proposed and verified by the detection of VOCs. Headspace solid phase microextraction (HS-SPME) was employed to investigate the release behavior of VOCs from PS MPs exposed to simulated ultraviolet (UV). Results indicated that although the physicochemical properties of the PS MPs showed no significantly change after UV-irradiation, a variety of toxic VOCs, such as benzene, toluene, and phenol were detected from the irradiated MPs. UV irradiation progressively enhanced the release amount of VOCs with total concentration up to 66 μg g after 30 d of exposure, about 2.4 times higher than that stored in the darkness (27 μg g). Some compounds (e.g., benzene and toluene) showed an upward trend over irradiation time, while others (e.g., styrene and 2-propenylbenzene) reduced over time. Results also found that the size of MPs could affect the release amounts but without consistent pattern for different VOCs detected in the headspace of the vial. In general, current study provided a new insight on the photo-aging process of MPs.
过度使用塑料导致塑料废物在环境中无处不在。风化会导致塑料性质发生变化，并导致各种化学物质释放，尤其是挥发性有机化合物 (VOCs)。通过检测 VOCs，提出并验证了聚苯乙烯 (PS) 微塑料 (MPs) 的可能光降解途径。采用顶空固相微萃取 (HS-SPME) 研究了 PS MPs 在模拟紫外线 (UV) 下暴露时 VOCs 的释放行为。结果表明，尽管 PS MPs 的物理化学性质在辐照后没有明显变化，但从辐照 MPs 中检测到了各种有毒 VOCs，如苯、甲苯和苯酚。UV 辐照逐渐增加了 VOCs 的释放量，在 30 天的暴露后，总浓度达到 66μg g，约为黑暗中储存量 (27μg g) 的 2.4 倍。一些化合物（例如苯和甲苯）随着辐照时间的增加呈上升趋势，而其他化合物（例如苯乙烯和 2-丙烯基苯）则随着时间的推移而减少。结果还发现，MPs 的尺寸会影响释放量，但对于瓶中顶空检测到的不同 VOCs 没有一致的规律。总的来说，本研究为 MPs 的光老化过程提供了新的见解。
