Sorption of tetracycline antibiotics by microplastics, associated mechanisms, and risk assessments

• Published in: The Science of the total environment 2024-12, Vol.958, p.178054, Article 178054
• Main Authors: Li, Xiang, Zeng, Lingling, Jiang, Huating, Sui, Jia, Shuang, Bao, Zhu, Liya, Tang, Junqian, Dai, Yingjie
• Format: Article
• Language: English
• Subjects: Microplastics; Response surface analysis; Sorption behavior; Tetracycline
• ISSN: 0048-9697; 1879-1026; 1879-1026
• DOI: 10.1016/j.scitotenv.2024.178054

In this study, we selected polyvinyl chloride (PVC), polyethylene (PE), and polystyrene (PS) as representative microplastics (MPs) to systematically investigate the sorption behavior of tetracycline (TC) antibiotics by MPs. Scanning electron microscopy, X-ray diffraction, Fourier transform-infrared spectroscopy, and adsorption experiments were applied to assess the sorption behavior of MPs. The results demonstrated that the sorption of TC by MPs was most favorable under neutral conditions, where a modest increase in the salt ion concentration enhanced the adsorption of TC by MPs. The saturation adsorption capacities for PVC, PE, and PS for TC were determined as 121.95 μg/g, 81.301 μg/g, and 178.57 μg/g, respectively. The strength of TC sorption by MPs followed the order of: PS > PVC > PE. Analysis of the sorption behavior of TC by MPs showed that the adsorption of TC by PE was weak and it readily desorbed, and thus their interaction will not lead to excessive compound pollution. By contrast, the adsorption of TC was high by PVC and PS, and they were not readily desorbed. [Display omitted] •The strength of the sorption between MPs and TC was PS > PVC > PE.•The environmental impact was determined through response RSM modeling.•An environmental risk assessment of the sorption between MPs and TC was conducted.•The sorption mechanisms of MPs and TC were analyzed in depth.