Department of Engineering, Aarhus University, Hangøvej 2, DK-8200 Aarhus N., Denmark.
Chair of Urban Water Systems Engineering, Technical University of Munich, Am Coloumbwall 3, 85748 Garching, Germany.
Bioresour Technol. 2019 Nov;291:121784. doi: 10.1016/j.biortech.2019.121784. Epub 2019 Jul 15.
Biomethanation exploits the ability of methanogenic archaea to convert CO and renewable H from electrolysis to biomethane. Biofilm reactors are promising for biomethanation scale-up due to high CH productivity and low energy input for H gas-liquid mass transfer. Effects of operational conditions on biofilm dynamics remain largely uncharacterized but may increase reactor potentials further. This study investigated the effect of hydraulic retention time (HRT) on methanogenic biofilm activity and composition. Commercial carriers floating in liquid were exposed to H/CO for 87 days with the liquid phase being subject to either 18 hours, 10 days, or 20 days HRT. Methanogenic biofilms were dominated by hydrogenotrophic methanogens, but biofilm CH productivity was enhanced at 18 hours HRT due to wash-out of competing planktonic species, which otherwise hampered proliferation of biofilm biomass at long HRT. It is suggested that high-rate biofilm reactors can increase methanogenic biofilm activity by minimizing the liquid's H exposure.
生物甲烷化利用产甲烷古菌将电解产生的 CO 和可再生 H 转化为生物甲烷的能力。生物膜反应器由于 CH 生产力高，H 气液传质所需的能量输入低，因此有望用于生物甲烷化放大。操作条件对生物膜动力学的影响在很大程度上尚未得到描述，但可能会进一步提高反应器的潜力。本研究考察了水力停留时间（HRT）对产甲烷生物膜活性和组成的影响。商业载体在液体中漂浮，与 H/CO 接触 87 天，液体相的 HRT 分别为 18 小时、10 天或 20 天。产甲烷生物膜主要由氢营养型产甲烷菌组成，但由于 18 小时 HRT 时竞争浮游生物的洗出，生物膜 CH 生产力得到提高，否则在长 HRT 时会阻碍生物膜生物量的增殖。研究表明，通过最小化液体的 H 暴露，高速率生物膜反应器可以提高产甲烷生物膜的活性。
