Key Laboratory of Industrial Ecology and Environmental Engineering (Dalian University of Technology), Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, China.
Key Laboratory of Industrial Ecology and Environmental Engineering (Dalian University of Technology), Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, China.
Water Res. 2020 May 15;175:115697. doi: 10.1016/j.watres.2020.115697. Epub 2020 Mar 7.
Suspended biofilm carriers mediating direct interspecies electron transfer (DIET)-based syntrophic metabolism is a promising strategy to enhance anaerobic digestion and methane production by associating the advantages of conductive suspended biofilm carriers and anaerobic integrated floating fixed-film and activated sludge (An-IFFAS) process. However, the current knowledge of DIET using conductive suspended biofilm carrier is still limited. In this study, novel electron mediator suspended biofilm carriers had been prepared by introducing a series of graphite powders (3 wt%, 5 wt% and 7 wt%) into high-density polyethylene (HDPE), and applied in An-IFFAS reactors. Results showed that An-IFFAS reactors filled with graphite-modified carriers could enhance the degradation of organic matters and the production of methane significantly in comparison with the control reactor filled with conventional HDPE carriers at organic loading rates (OLRs) of 5.9-23.7 kg COD/m/d. Microbial analysis proved that 7 wt% graphite-modified carrier improved approximately 4.2% abundance of Geobacter and 7.3% abundance of electrotrophic methanogens (Methanothrix) that exchange electron via DIET comparing with that of HDPE carriers, respectively. These findings demonstrated that electron mediator suspended biofilm carrier was able to potentially proceed DIET and enhance the efficiency of anaerobic digestion and recover CH-related energy.
悬浮生物膜载体介导的直接种间电子传递（DIET）共生代谢是一种很有前途的策略，可以通过结合导电悬浮生物膜载体和厌氧综合浮动固定膜和活性污泥（An-IFFAS）工艺的优势来提高厌氧消化和甲烷生产效率。然而，目前关于使用导电悬浮生物膜载体的 DIET 的知识仍然有限。在本研究中，通过向高密度聚乙烯（HDPE）中引入一系列石墨粉末（3wt%、5wt%和 7wt%），制备了新型电子介体悬浮生物膜载体，并将其应用于 An-IFFAS 反应器中。结果表明，与填充传统 HDPE 载体的对照反应器相比，在有机负荷率（OLR）为 5.9-23.7kg COD/m/d 时，填充有石墨改性载体的 An-IFFAS 反应器可以显著提高有机物的降解和甲烷的生成。微生物分析证明，与 HDPE 载体相比，7wt%石墨改性载体分别使通过 DIET 交换电子的 Geobacter 增加了约 4.2%，电营养产甲烷菌（Methanothrix）增加了 7.3%。这些发现表明，电子介体悬浮生物膜载体能够进行潜在的 DIET，并提高厌氧消化的效率和回收 CH 相关能量。
