The aging behavior of polyvinyl chloride microplastics promoted by UV-activated persulfate process

• Published in: Journal of hazardous materials 2022-02, Vol.424 (Pt B), p.127461-127461, Article 127461
• Main Authors: Ouyang, Zhuozhi, Li, Shuxing, Zhao, Manyi, Wangmu, Quzong, Ding, Rui, Xiao, Chuanqi, Guo, Xuetao
• Format: Article
• Language: English
• Subjects: Artificially-accelerated aging; Mechanism; Microplastics; Oxidation-Reduction; Photo-transformation; Plastics; Polyvinyl Chloride; PVC; Sulfate radical; Water Pollutants, Chemical - analysis
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2021.127461

Microplastics (MPs) experienced different aging processes in environment. Literatures about effect of artificially-accelerated aging on MPs behavior are still insufficient. The accelerated process induced by ultraviolet(UV)-activated persulfate (PS) is a promising technology for obtaining different aged MPs to understand long-term aging behavior. In the work, the aging behavior of polyvinyl chloride (PVC) accelerated by UV/PS system were investigated. It exhibited a dechlorination with 58.495 ± 6.090 mg/L Cl- release after 35 h UV-activated PS (0.01 M) process. The treatment led to significant alternations on surface morphology and chemical feature of PVC. The crystallinity was increased, and average size was reduced from 154.11 µm to 119.28 µm with aging time. Subsequently, many smaller size particles were produced. Furthermore, the process induced the breaking of backbone. Simultaneously, more oxygen-containing functional groups were identified. The oxidation reaction accelerated by sulfate radical (SO4•−) and reactive oxygen species (ROS) was predominant, which immensely promoted aging process. Sustained high levels of free radical contributed to production of alcohols and carboxylic acids short chain organics. The study explored aging behavior of PVC accelerated by UV/PS system, which could be helpful for understanding environmental behavior and providing further information to assess potential risks of MPs. [Display omitted] •The aging properties of PVC accelerated by UV/PS system were firstly investigated.•The treated PVC experienced the dechlorination reaction.•The production of SO4•− and ROS was predominant, promoting the aging of PVC.•The alcohols and carboxylic acids short chain organics were identified.