Anaerobic co-digestion of PBAT/PLA/starch commercial bio-plastic bags with food waste: Effects on methane production and microbial community structure

This study investigates the impact of the temperature and mixing ratios on the co-digestion of biodegradable plastic bags and food waste. Based on current experimental results of methane production, thermophilic digestion with a plastic addition rate of 30% exhibited better performance. Through SEM, FTIR, and XRD analyses, we examined the structural alterations in non-degraded and degraded bioplastic polymers post-anaerobic digestion. The results showed that PBAT/PLA/starch (Polybutylene adipate terephthalate/Polylactic acid/starch) bioplastics decompose slowly, and their full potential for anaerobic co-digestion with food waste and generation of renewable energy such as methane may not be fully realized. The diversity of microbial systems decreases with an increase in bioplastics addition ratio, which increases the instability of anaerobic fermentation systems. From the aspect of bacterial community, the addition of bioplastics has little effect on the phylum level, but has a greater impact at the class level. •An optimal condition of bioplastics anaerobic co-digestion was achieved.•Temperature impacted more than bioplastics ratio.•Bioplastics lowered the diversity of microbial community.•Bioplastics degradation should be furtherly enhanced by more means within Standard 30-day HRT co-digestion.