College of Natural Resources and Environment, South China Agricultural University/Key Laboratory of Agro-Environment in the Tropics, Ministry of Agriculture of China, Guangzhou 510642, China; Guangdong Provincial Key Laboratory of Eco-Circular Agriculture/Guangdong Engineering Research Center for Modern Eco-agriculture and Circular Agriculture, Guangzhou 510642, China.
Centre for Regional and Rural Futures, Faculty of Science, Engineering and Built Environment, Deakin University, Burwood, VIC 3125, Australia.
J Hazard Mater. 2021 Aug 5;415:125640. doi: 10.1016/j.jhazmat.2021.125640. Epub 2021 Mar 18.
A 250-day batch experiment was conducted to examine the generation of microplastic particles from degradation of polycarbonate films in 3 aqueous media of environmental relevance. The microplastic particles generated from the experiment were characterized by SEM/EDS and micro-FTIR analysis. Hydrolysis was responsible for the cleavage of carbon-oxygen bonds in the carbonate group of polycarbonate backbone and detachment of micro-sized plastic particles from the PC film surfaces. The deionized water treatment had the highest concentration of total organic carbon and the greatest number of microplastic particles among the three treatments. Either elevated acidity or the presence of hydroxyl radical did not enhance the hydrolytic degradation of the PC films and generation of microplastic particles though hydroxyl radical caused oxidative degradation of polycarbonate by attacking the organic group but not the carbonate group. Bisphenol A was not detected in any of the treatments. The microplastic particles generated from the current experiment were highly irregular, which may have different physicochemical and toxic behaviours from the spheric synthetic ones that were frequently used in toxicity experiments.
进行了一项为期 250 天的批次实验，以研究在 3 种具有环境相关性的水介质中，聚碳酸酯薄膜降解产生微塑料颗粒的情况。通过扫描电子显微镜/能谱仪（SEM/EDS）和微傅里叶变换红外光谱分析（micro-FTIR）对实验中产生的微塑料颗粒进行了表征。水解作用导致聚碳酸酯主链碳酸酯基团中的碳-氧键断裂，并从 PC 薄膜表面脱落出微塑料颗粒。在三种处理方式中，去离子水处理的总有机碳浓度最高，微塑料颗粒数量最多。尽管羟基自由基通过攻击有机基团而不是碳酸酯基团来氧化降解聚碳酸酯，但酸性升高或存在羟基自由基都不会增强 PC 薄膜的水解降解和微塑料颗粒的生成。在任何处理方式中都没有检测到双酚 A。本实验产生的微塑料颗粒极不规则，其物理化学和毒性行为可能与经常用于毒性实验的球形合成微塑料颗粒不同。
