We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Unraveling synergistic cascade inhibition of methane production in anaerobic digestion system by polyethylene microplastics and domestic sewage: Physical adsorption, metabolic disruption, and microbial community decoupling
Summary
Researchers systematically explored how the co-presence of polyethylene microplastics and domestic sewage inhibits methane production in anaerobic digestion systems, finding that physical adsorption of microplastics, propionic acid accumulation, and microbial community decoupling identified via multi-omics analysis collectively suppressed cumulative CH4 production by 41.8% compared to controls.
The coexistence of microplastics (MPs) and domestic sewage (DS) poses unprecedented challenges to anaerobic digestion systems. Here, the cascades inhibitory mechanism of polyethylene microplastics (PE-MPs) and DS was systematically explored. Compared with the control group, the cumulative CH production of 289.77 mL/g VS in the WL group (containing DS and PE-MPs) was 41.8 % accompanied by abnormal accumulation of propionic acid (3612 mg/L) and delayed pH recovery. Multi-omics analysis indicated that PE-MPs underwent physical adsorption with reducing substrate availability and impeding nutrient cycling, and biochemical inhibition inducing a 1.9-fold increase in superoxide dismutase and a 91.43 % decrease in acetate kinase. Additionally, ecological process reshaping was characterized by the dominance of Firmicutes with an 119 % increase and the reduction of Methanosarcina with 82 %. Zero model analysis indicated that the stochastic processes (44 %) dominated the community assembly of the WL group, and the network modularization index (0.533) significantly increased. PLS-SEM displayed CH production was a significant negative correlation with alpha diversity (β=-0.24, p < 0.01) and key enzyme activity (β=-0.38, p < 0.01), while volatile fatty acids had a positive correlation with methanogens (β=0.18, p < 0.05). Collectively, these findings displayed DS and PE-MPs significantly reduced nutrient content, induced oxidative stress, and reshaped community composition and assembly.