Enhancing sludge methanogenesis with improved redox activity of extracellular polymeric substances by hematite in red mud.
Enhancing sludge methanogenesis with improved redox activity of extracellular polymeric substances by hematite in red mud.
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DOI：
10.1016/j.watres.2018.01.062
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发表时间：
2018-05
期刊：
影响因子：
12.8
通讯作者：
Jie Ye;Andong Hu;G. Ren;Man Chen;Jiahuan Tang;Panyue Zhang;Shungui Zhou;Zhen He
中科院分区：
文献类型：
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作者：
Jie Ye;Andong Hu;G. Ren;Man Chen;Jiahuan Tang;Panyue Zhang;Shungui Zhou;Zhen He
不同的导电材料已被用来刺激产甲烷过程中的直接种间电子转移（DIET），但很少有研究关注导电材料与胞外聚合物（EPS）之间的相互作用，例如对污泥聚集和EPS氧化还原活性的影响。本研究旨在系统研究含45.46wt%赤铁矿的赤泥对废弃活性污泥厌氧消化过程中产甲烷作用的影响。结果表明，赤铁矿中的多价阳离子有效促进了大而致密的聚集体的形成，这可能有助于 DIET 过程中快速的直接电子交换。同时，更多的氧化还原活性介质，包括c型细胞色素（c-Cyts）和腐殖质，特别是在紧密结合的EPS（TB-EPS）中，以及赤泥引入的更多氧化还原活性金属（例如Fe）可以参与互养细菌与产甲烷古菌之间的种间电子传递过程，这也促进了甲烷产量（与对照相比增加了35.52±2.64％）。这项研究为全面评估导电材料在产甲烷过程中的作用提供了初步的科学证据，对自然和工程环境中导电矿物的生物地球化学氧化还原过程具有重要意义。
Different conductive materials have been employed to stimulate direct interspecies electron transfer (DIET) during methanogenesis, but few studies have been concerned with the interaction between conductive materials and extracellular polymeric substances (EPS) such as the effect on sludge aggregation and redox activity of EPS. This study aims to systematically investigate the role of red mud with 45.46 wt% hematite on methanogenesis during the anaerobic digestion of waste activated sludge. The results showed that the multivalent cations from hematite effectively promoted the formation of large and compact aggregates, which might contribute to the rapid direct electron exchange during the DIET process. Meanwhile, more redox-active mediators includingc-type cytochromes (c-Cyts) and humic substances, particularly in tight-bound EPS (TB-EPS), and more redox-active metals such as Fe introduced by red mud could take part in the interspecies electron transfer process between syntrophic bacteria and methanogenic archaea, which also promoted methane production (35.52 ± 2.64% increase compared with the control). This study provided initial scientific evidence to comprehensively assess the role of conductive materials during methanogenesis, with important implications for the biogeochemical redox processes of conductive minerals in natural and engineered environments.