Effects of chlorination on microplastics pollution: Physicochemical transformation and chromium adsorption

The large number of microplastics (MPs) that appear in the environment has drawn much attention. Few studies, however, have examined the transformation of MPs in water treatment processes and their effects on environ-mental pollutants. In this study, the alteration of the physicochemical characteristics of polyethylene and thermoplastic polyurethane upon chlorination, as well as the influence of this alteration on contaminants, were investigated. The findings indicated that microplastics underwent significant morphology and O-functional groups changes during chlorination. It is noteworthy that the mechanisms controlling the chlorination treatment of the two MPs are clearly different. The results of aggregation and adsorption experiments showed that the chlorination treatment enhanced the aggregation ability of the MPs in brine and their interaction with Cr(VI). The present discoveries further suggested that water treatment could alter the migration capacity of micro-plastics and the distribution of contaminants in the aqueous environment by altering the adsorption of micro-plastics to the contaminants.

Automated summary

This study investigated the changes in physicochemical characteristics of polyethylene and thermoplastic polyurethane during chlorination, and the influence of these changes on contaminants. The findings revealed significant morphology and O-functional group changes in microplastics during chlorination. Moreover, the mechanisms controlling the chlorination treatment differed between the two types of microplastics. The research also showed that chlorination treatment enhanced the aggregation ability of microplastics in brine and their interaction with Cr(VI). These discoveries suggest that water treatment processes can alter the migration capacity of microplastics and the distribution of contaminants in the aquatic environment by affecting the adsorption of microplastics to contaminants.