School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi'an, 710021, PR China.
School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi'an, 710021, PR China.
J Environ Manage. 2022 Nov 1;321:115997. doi: 10.1016/j.jenvman.2022.115997. Epub 2022 Aug 17.
Microplastics (MPs) pollution has become a major environmental problem and poses a risk to a variety of organisms. In this study, the photoaging behavior of acrylonitrile butadiene styrene microplastics (ABS-MP) in aqueous environment was investigated under simulated solar irradiation. Results showed that the long chains of ABS-MP broke under the light irradiation, and its thermal stability was reduced. ABS-MP was oxidized during photoaging and produced a large number of oxygen-containing functional groups. Structure destruction of ABS-MP decreased the formation of environmentally persistent free radicals (EPFRs) and further photoirradiation generated secondary EPFRs. Nuclear magnetic resonance (NMR) analysis of the aged leachates confirmed that ABS-MP was oxidized and some small molecular fragments were dropped during photoaging. Meanwhile, C-Br bond broke of additive tetrabromobisphenol A (TBBPA) resulting in more bromine released into water and Sb(III) of additive SbO was oxidized to Sb(V) during photoaging. These findings illustrate the necessity of considering the aging of MPs in natural environment, expand the understanding of the potential harm and fate of MPs in aqueous environment, which is important for the management of MPs.
微塑料（MPs）污染已成为一个主要的环境问题，对各种生物都构成了风险。在这项研究中，模拟太阳辐射下研究了丙烯腈-丁二烯-苯乙烯微塑料（ABS-MP）在水相环境中的光老化行为。结果表明，ABS-MP 的长链在光照下断裂，其热稳定性降低。ABS-MP 在光老化过程中被氧化，并产生大量含氧官能团。ABS-MP 的结构破坏减少了环境持久性自由基（EPFRs）的形成，进一步的光辐照产生了二次 EPFRs。老化浸出液的核磁共振（NMR）分析证实，ABS-MP 在光老化过程中被氧化，一些小分子片段脱落。同时，添加剂四溴双酚 A（TBBPA）中的 C-Br 键断裂，导致更多的溴释放到水中，添加剂 SbO 中的 Sb(III)在光老化过程中被氧化为 Sb(V)。这些发现说明了在自然环境中考虑 MPs 老化的必要性，扩展了对 MPs 在水相环境中的潜在危害和命运的理解，这对于 MPs 的管理非常重要。
