Wu Fei, Xie Jiaqian, Xin Xiaodong, He Junguo
School of Water, Energy and Environment (SWEE), Cranfield University, Cranfield, United Kingdom.
Department of Environmental Science and Engineering, Huaqiao University, Xiamen, China.
Front Microbiol. 2022 Nov 15;13:999647. doi: 10.3389/fmicb.2022.999647. eCollection 2022.
The conductive media was capable to enhance anaerobic digestion and promote direct interspecific electron transfer (DIET). In this study, the effects of activated carbon- and graphite-conductive media on promoting anaerobic digestion efficiency of waste activated sludge were experimentally studied. The results show that the 100 mesh-activated carbon group reactor produced a largest biogas yield of 468.2 mL/g VSS, which was 13.8% higher than the blank test. The graphite group reactor with 400-grain size produced a largest biogas yield of 462.9 mL/g VSS, which was 12.5% higher than the blank test. Moreover, the optimal particle size of such two carbon- conductive mediators were optimized for enhancing degradation efficiency of VSS, TCOD, total protein and total polysaccharide of waste sludge. Activated carbon was capable to promote the hydrolytic acidification stage in anaerobic digestion of waste sludge. When the particle size reduced to the optimal particle size, the promoting effect could be strengthened for producing more hydrolytic acidification products for methanogenesis. However, in the graphite group, the methane production is increased by promoting the consumption of hydrolysis and acidification products and is enhanced with the particle size reduction, thus promoting the methanogenesis process, and improving the anaerobic digestion efficiency. Microbial community analysis showed that both activated carbon and graphite cultivated the genera of , , , which promoted the improvement of methane production through the acetate debris methanogenesis pathway.
导电介质能够增强厌氧消化并促进种间直接电子转移（DIET）。本研究通过实验研究了活性炭和石墨导电介质对提高废弃活性污泥厌氧消化效率的影响。结果表明，100目活性炭组反应器产生的最大沼气产量为468.2 mL/g VSS，比空白试验高13.8%。粒径为400目的石墨组反应器产生的最大沼气产量为462.9 mL/g VSS，比空白试验高12.5%。此外，对这两种碳导电介质的最佳粒径进行了优化，以提高废弃污泥中VSS、总化学需氧量（TCOD）、总蛋白和总多糖的降解效率。活性炭能够促进废弃污泥厌氧消化中的水解酸化阶段。当粒径减小到最佳粒径时，促进作用增强，可产生更多用于甲烷生成的水解酸化产物。然而，在石墨组中，通过促进水解酸化产物的消耗来增加甲烷产量，并且随着粒径减小而增强，从而促进甲烷生成过程，提高厌氧消化效率。微生物群落分析表明，活性炭和石墨都培养了 、 、 属，它们通过乙酸碎片甲烷生成途径促进了甲烷产量的提高。
