The release degradation and distribution of PVC microplastic-originated phthalate and non-phthalate plasticizers in sediments

초록

This study investigated the leaching of phthalate and non-phthalate plasticizers from polyvinyl chloride microplastics (MPs) into sediment and their degradation over a 30-d period via abiotic and biotic processes. The results showed that 35–79% of plasticizers were released into the sediment from the MPs and > 99.9% degradation was achieved. Although a significantly higher degradation was found in plasticizer-added microcosms under biotic processes (overall 94%) there was a noticeable abiotic loss (72%) suggesting that abiotic processes also play a role in plasticizer degradation. Interestingly when compared with the initial sediment-water partitioning for plasticizers the partition constants for low-molecular-weight compounds decreased in both microcosms whereas those for high-molecular-weight compounds increased after abiotic degradation. Furthermore changes in the bacterial community abundance of plasticizer-degrading bacterial populations and functional gene profiles were assessed. In all the microcosms a decrease in bacterial community diversity and a notable shift in bacterial composition were observed. The enriched potential plasticizer-degrading bacteria were Arthrobacter Bacillus Desulfovibrio Desulfuromonas Devosia Gordonia Mycobacterium and Sphingomonas among which Bacillus was recognized as the key plasticizer degrader. Overall these findings shed light on the factors affecting plasticizer degradation the microbial communities potentially involved in biodegradation and the fate of plasticizers in the environment. © 2024 Elsevier B.V.

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