Adsorption behavior of triazine pesticides on polystyrene microplastics aging with different processes in natural environment

• Published in: Environmental pollution (1987) 2024-09, Vol.356, p.124319, Article 124319
• Main Authors: Zeng, Zihang, Jia, Bingni, Liu, Xiaofeng, Chen, Lixiang, Zhang, Peng, Qing, Taiping, Feng, Bo
• Format: Article
• Language: English
• Subjects: adsorption; Adsorption behavior; Adsorption mechanism; Aging methods; ecotoxicology; environmental exposure; Escherichia coli; hydrogen; hydrophobicity; metribuzin; Microplastics; pollution; polystyrenes; risk; Triazine herbicides
• ISSN: 0269-7491; 1873-6424; 1873-6424
• DOI: 10.1016/j.envpol.2024.124319

The presence of microplastics in the ecological environment, serving as carriers for other organic pollutants, has garnered widespread attention. These microplastics exposed in the environment may undergo various aging processes. However, there is still a lack of information regarding how these aged microplastics impact the environmental behavior and ecological toxicity of pollutants. In this study, we modified polystyrene microplastics by simulating the aging behavior that may occur under environmental exposure, and then explored the adsorption behavior and adsorption mechanism of microplastics before and after aging for typical triazine herbicides. It was shown that all aging treatments of polystyrene increased the adsorption of herbicides, the composite aged microplastics had the strongest adsorption capacity and the fastest adsorption rate, and of the three herbicides, metribuzin was adsorbed the most by microplastics. The interactions between microplastics and herbicides involved mechanisms such as hydrophobic interactions, surface adsorption, the effect of π-π interactions, and the formation of hydrogen bonds. Further studies confirmed that microplastics adsorbed with herbicides cause greater biotoxicity to E. coli. These findings elucidate the interactions between microplastics before and after aging and triazine herbicides. Acting as carriers, they alter the environmental behavior and ecological toxicity of organic pollutants, providing theoretical support for assessing the ecological risk of microplastics in water environments. [Display omitted] •Heat, UV, biological, and combined aging treatments were applied to polystyrene.•The adsorption capacity of aged polystyrene is greater than that of the original.•Adsorption involves hydrophobicity, hydrogen bonds, π-π, and surface interactions.•Aged polystyrene's toxicity to E. coli rises after herbicide adsorption.