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.
Chemosphere. 2022 Jul;299:134399. doi: 10.1016/j.chemosphere.2022.134399. Epub 2022 Mar 21.
A batch experiment was conducted to observe the liberation of micro- and nano-sized plastic particles and plastic additive-originated organic compounds from poly(vinyl chloride) under radiation-free ambient conditions. The weathering of PVC films in deionized water resulted in isolated pockets of surface erosion. Additional OH from Fenton reaction enhanced PVC degradation and caused cavity erosion. The detachment of plastic fragments from the PVC film surfaces was driven by autocatalyzed oxidative degradation. Over 90% of micro-sized plastic particles were <60 μm in length. The detached plastic fragments underwent intensified weathering, which involved strong dehydrochlorination and oxidative degradation. Further fragmentation of micro-sized particles into nano-sized particles was driven by oxidative degradation with complete dehydrochlorination being achieved following formation of nanoplastics. 20 organic compounds released from the PVC films into the solutions were identified. And some of them can be clearly linked to common plastic additives. In the presence of additional OH, the coarser nanoplastic particles (>500 nm) tended to be rapidly disintegrated into finer plastic particles (<500 nm), while the finest fraction of nanoplastics (<100 nm) could be completely decomposed and disappeared from the filtrates. The micro(nano)plastics generated from the PVC weathering were highly irregular in shape.
进行了一批实验，以观察在无辐射环境条件下，聚氯乙烯（PVC）中微纳米塑料颗粒和塑料添加剂衍生的有机化合物的释放情况。在去离子水中，PVC 薄膜的风化导致表面侵蚀的孤立区域。芬顿反应产生的额外 OH 增强了 PVC 的降解，并导致空蚀。塑料碎片从 PVC 膜表面的脱落是由自催化氧化降解驱动的。超过 90%的微塑料颗粒长度小于 60 μm。脱落的塑料碎片经历了强化风化，包括强烈的脱氯化氢和氧化降解。微尺寸颗粒进一步碎片化形成纳米尺寸颗粒，这是由完全脱氯化氢后形成的纳米塑料的氧化降解驱动的。从 PVC 薄膜释放到溶液中的 20 种有机化合物被鉴定出来。其中一些可以明显与常见的塑料添加剂联系起来。在额外 OH 的存在下，较粗的纳米塑料颗粒（>500nm）往往会迅速分解成更细的塑料颗粒（<500nm），而最细的纳米塑料颗粒（<100nm）可以完全分解并从滤液中消失。从 PVC 风化产生的微（纳）塑料形状极不规则。
