Abstract:

The salinity in food waste has an adverse effect on its anaerobic digestion and methane production. In order to solve this problem, the effects of iron-carbon microbial electrolytic cells on the thermophilic anaerobic digestion were studied. Zero-valent iron was used for the anode of the microbial electrolytic cells to improve the salt tolerance of microorganisms and enhance the oxidation of organics, thereby promoting the methane production. The results show that the maximum cumulative methane yield of the iron-carbon microbial electrolytic cells reaches 1110.67mL, which increases 68.18% compared to the control group. With the increase of Na⁺ concentration, the hydrolysis and acidification process is inhibited, and the iron-carbon microbial electrolytic cells promote the process of microbial degradation of organics and the process of converting propionic acid and butyric acid into acetic acid. From the microbiological analysis,the abundance of Methanomassiliicoccus in the iron-carbon microbial electrolytic cells group is enhanced, accounting for 52% of the anode. Metabolic pathway analysis shows that the iron-carbon microbial electrolytic cells improve the salt tolerance of microorganisms, promote the hydrolysis and acidification process and increase the gene abundance of enzymes in the process of acetic acid decarboxylation and CO₂ reduction in the process of methanogenesis. Iron-carbon microbial electrolytic cells are beneficial to the anaerobic digestion of food waste.

Key words: electrolysis, biofilm, bioenergy, methane, anaerobic

摘要：

目前餐厨垃圾中的盐度对其厌氧消化产甲烷有不利影响。为了解决这一问题，本研究通过使用铁-碳微生物电解池来强化高温厌氧消化。本文使用零价铁作为微生物电解池的阳极，提高微生物的耐盐能力，增强了阳极的氧化作用，从而促进产甲烷过程。结果表明，铁-碳微生物电解池的累积产甲烷量最高达到了1110.67mL，比对照组提高了68.18%。随着Na⁺浓度的提高，水解酸化过程受到了抑制，而铁-碳微生物电解池促进了微生物降解有机物的过程，并且促进了丙酸和丁酸转化为乙酸的过程。微生物群落结构分析表明，铁-碳微生物电解池促进了Methanomassiliicoccus的生长，在阳极上占比52%。代谢通路分析表明，铁-碳微生物电解池提高了微生物的耐盐能力，促进了水解酸化过程，并且提高了产甲烷过程中乙酸脱羧和二氧化碳还原过程中相关酶的基因丰度，强化高温厌氧消化。

关键词: 电解, 生物膜, 生物能源, 甲烷, 厌氧