Surpassing the current limitations of high purity H-2 production in microbial electrolysis cell (MECs): Strategies for inhibiting growth of methanogens

Microbial electrolysis cells (MECs) are perceived as a potential and promising innovative biotechnological tool that can convert carbon-rich waste biomass or wastewater into hydrogen (H-2) or other value-added chemicals. Undesired methane (CH4) producing H-2 sinks, including methanogens, is a serious challenge faced by MECs to achieve high-rate H-2 production. Methanogens can consume H-2 to produce CH4 in MECs, which has led to a drop of H-2 production efficiency, H-2 production rate (HPR) and also a low percentage of H-2 in the produced biogas. Organized inference related to the interactions of microbes and potential processes has assisted in understanding approaches and concepts for inhibiting the growth of methanogens and profitable scale up design. Thus, here in we review the current developments and also the improvements constituted for the reduction of microbial H-2 losses to methanogens. Firstly, the greatest challenge in achieving practical applications of MECs; undesirable microorganisms (methanogens) growth and various studied techniques for eliminating and reducing methanogens activities in MECs were discussed. Additionally, this extensive review also considers prospects for stimulating future research that could help to achieve more information and would provide the focus and path towards MECs as well as their possibilities for simultaneously generating H-2 and waste remediation. (C) 2017 Elsevier B.V. All rights reserved.