Hydrothermal Pretreatment-Anaerobic Digestion of Biodegradable Plastic and Food Waste: A Perfect Strategy for Degrading Biodegradable Plastic

Abstract

As the biodegradable plastic (BP) is replacing traditional plastic, integrating its anaerobic co-digestion with food waste poses a challenge. This study addresses this challenge after hydrothermal pretreatment without modifying the current anaerobic process. After a hydrothermal pretreatment at 180°C for 1 h, the anaerobic co-digestion system yielded synergistic effects, characterized by an 82.16% mass loss rate of BP and a 12.32% rise in methane production at thermophilic temperature. SEM images revealed increased porosity and cracking on pretreated samples, while FTIR showed a significant decrease in the characteristic absorption peak intensities of -C=O and -C-O- after pretreatment. High-throughput sequencing revealed enhanced substrate availability and increased microbial diversity following hydrothermal pretreatment. The Defluviitoga and Actinomyces played pivotal roles in the degradation of BP. Redundancy analysis revealed a positive correlation between hydrothermal pretreatment and the abundance of Methanothermobacter, suggesting that hydrothermal pretreatment promotes methane production by influencing the structure of specific archaeal communities.

Keywords: hydrothermal pretreatment, Biodegradable plastic, Food waste, anaerobic co-digestion