Anaerobic electrochemical digestion (AED) is an effective system for recovering biogas from organic wastes. However, the effects of different anode potentials on anaerobic activated sludge remain unclear. This study confirmed that biofilms exhibited the best electroactivity at -0.2 V (vs. Ag/AgCl) compared to -0.4 V and 0 V. Gas was further regulated, with the highest hydrogen content (47 ± 7 %) observed at -0.2 V. The 0 V system produced the largest amount of methane (70 ± 8 %) and exhibited the greatest presence of hydrogen-utilizing microorganisms. The gas yield at -0.4 V was the lowest, with no hydrogen detected. Excess bioelectrohydrogen at -0.2 V and 0 V caused the co-enrichment of Methanobacterium and Acetoanaerobium, establishing a thermodynamically feasible current-acetate-hydrogen electron cycle to improve electrogenesis. These results provide insights into the regulatory strategies of MEC technology during anaerobic digestion, which play a decisive role in determining the composition of biogas.
Keyphrases
- anaerobic digestion
- sewage sludge
- antibiotic resistance genes
- microbial community
- municipal solid waste
- wastewater treatment
- visible light
- room temperature
- gold nanoparticles
- transcription factor
- reduced graphene oxide
- ionic liquid
- carbon dioxide
- label free
- heavy metals
- molecularly imprinted
- high resolution
- candida albicans
- quantum dots
- risk assessment
- electron transfer
- climate change