The influence of mixture proportions of polypropylene, polyvinyl chloride, and polyester microplastics on methane production: Integrative analysis of microbial diversity, enzymatic and metabolic profiles
1
Issued Date
2025-10-01
Resource Type
ISSN
09575820
Scopus ID
2-s2.0-105013849579
Journal Title
Process Safety and Environmental Protection
Volume
202
Rights Holder(s)
SCOPUS
Bibliographic Citation
Process Safety and Environmental Protection Vol.202 (2025)
Suggested Citation
Poosrisom S., Wongfaed N., Jumpa T., Chiangjong W., Xia A., Reungsang A., Sittijunda S. The influence of mixture proportions of polypropylene, polyvinyl chloride, and polyester microplastics on methane production: Integrative analysis of microbial diversity, enzymatic and metabolic profiles. Process Safety and Environmental Protection Vol.202 (2025). doi:10.1016/j.psep.2025.107752 Retrieved from: https://repository.li.mahidol.ac.th/handle/123456789/111863
Title
The influence of mixture proportions of polypropylene, polyvinyl chloride, and polyester microplastics on methane production: Integrative analysis of microbial diversity, enzymatic and metabolic profiles
Corresponding Author(s)
Other Contributor(s)
Abstract
Microplastic pollution has emerged as a critical environmental challenge, with significant quantities accumulating in wastewater treatment systems where anaerobic digestion (AD) is commonly employed for biogas production and waste management. As microplastics increasingly enter AD systems through sewage sludge and organic waste streams, understanding their effects on methane production becomes essential for maintaining renewable energy recovery and process efficiency. This study investigated the effects of mixed microplastic (MP) proportions on AD processes using a mixture design. Various proportions of polypropylene (PP-MP), polyvinyl chloride (PVC-MP), and polyester (PES-MP) microplastics were tested. The proportion of mixed microplastics that minimized negative influence on methane production was 79.9 % PP-MPs, 11.1 % PVC-MPs, and 9.0 % PES-MPs (MPs4), yielding 3554 mL-CH₄/L. In contrast, proportions of 78.5 % PP-MPs, 15.1 % PVC-MPs, and 6.4 % PES-MPs (MPs1) maximized negative influence, producing 3108 mL-CH₄/L. However, all MP-containing experiments showed reduced methane production compared to the MP-free control. SEM-EDS analysis revealed altered granular sludge morphology and surface modifications due to microplastic exposure. 16S rRNA high-throughput sequencing analysis showed MP-induced shifts in microbial communities, with increased hydrogenotrophic methanogens and decreased acetoclastic methanogens in MPs1 and MPs4 treatments. PICRUSt2 functional prediction analysis revealed the presence of peroxidase, triacylglycerol lipase, haloalkane dehalogenase, and carboxylesterase enzymes, indicating potential microplastic biodegradation capabilities within the microbial communities. LC-MS metabolomic analysis revealed distinct clustering patterns with altered levels of metabolites related to AD stages, plastic degradation, and reduced quorum-sensing molecules under MP conditions, indicating disrupted microbial communication. These findings provide the first systematic investigation of mixed microplastic effects on AD processes, offering crucial insights for developing microplastic-resilient anaerobic digestion systems in an era of escalating plastic pollution.