High-efficiency methanogenesis via kitchen wastes served as ethanol source to establish direct interspecies electron transfer during anaerobic Co-digestion with waste activated sludge

WATER RESEARCH

卷:176

Article

Li, Yang^1,2  Tang, Yapeng²  Xiong, Pu²  Zhang, Mingqian²  Deng, Qingling²  Liang, Dandan³  Zhao, Zhiqiang¹  Feng, Yujie³  Zhang, Yaobin¹ 

[1] Dalian Univ Technol, Key Lab Ind Ecol & Environm Engn, Sch Environm Sci & Technol, Minist Educ, Dalian 116024, Peoples R China

[2] Dalian Univ Technol, Sch Food & Environm, Key Lab Ind Ecol & Environm Engn, Minist Educ, Panjin 124221, Peoples R China

[3] Harbin Inst Technol, State Key Lab Urban Water Resource & Environm, Harbin 150090, Peoples R China

关键词: Kitchen wastes (KW);    Waste activated sludge (WAS);    Anaerobic Co-Digestion (AcoD);    Biological ethanol-type fermentation pretreatment (BEFP);    Direct interspecies electron transfer (DIET);   

DOI  :  10.1016/j.watres.2020.115763

来源: Elsevier

【 摘 要 】

Kitchen wastes (KW) have been widely investigated for bio-ethanol production, while no study utilizes KW as ethanol source to stimulate the methanogenic communities to perform direct interspecies electron transfer (DIET), since the excess acidity contained after the biological ethanol-type fermentation pretreatment (BEFP) can seriously inhibit the DIET-based syntrophic metabolism. In this study, a strategy that utilized waste activated sludge (WAS) as co-substrate to relieve the excess acidity after BEFP during anaerobic co-digestion (AcoD) was proposed. The results showed that, under the mixed ratio of 1:2 and 1:5 (KW:WAS, volume ratio), both methane production and organic compound removal evidently increased, compared with that treating the sole WAS. Conversely, under the other mixed ratios (sole KW, 5:1, 2:1 and 1:1), no methane but the evident hydrogen production was detected, and syntrophic metabolism of organic acids and alcohols was prevented. Three-dimensional excitation emission matrix (3D-EEM) analysis showed that the protein-like organic compounds contained in both KW and WAS were effectively degraded. Furthermore, the maximum methane production potential from WAS during AcoD (260.5 +/- 4.1 and 264.3 +/- 2.7 mL/g-COD) was higher than that treating sole WAS (250.8 +/- 0.1 mL/g-COD). Microbial community analysis showed that, some genera capable of metabolizing the complex organic compounds with the reduction of the elemental sulfur or equipped with the electrically conductive pili were specially enriched during AcoD under the mixed ratio of 1:2 and 1:5. They might proceed DIET with methanogens, such as Methanosarcina and Methanospirillum species, to maintain the syntrophic metabolism effective and stable, since the abundance of both Methanosarcina and Methanospirillum species evidently increased. (C) 2020 Elsevier Ltd. All rights reserved.

【 授权许可】

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