Microbial electrochemical systems for sustainable biohydrogen production: Surveying the experiences from a start-up viewpoint

Abstract

The start-up of microbial electrohydrogenesis cells (MECs) is a key-step to realize efficient biohydrogen generation and adequate, long-term operation. This review paper deals with the lessons and experiences reported on the most important aspects of H 2 producing MEC start-up. The comprehensive survey covers the assessment and discussion of the main influencing factors and methods (e.g. inocula selection, enrichment, acclimation, operating conditions and cell architecture) that assist the design of MECs. This work intends to be a helpful guide for the interested readers about the strategies employed to successfully establish microbial electrochemical cells for sustainable biohydrogen production.

Microbial electrolysis cell as an emerging versatile technology: a review on its potential application, advance and challenge

“…). The cathode chamber was incubated with anaerobic sludge suspensions . The anode and the cathode are blocked by a separator to reduce H 2 diffusion to the anode and reduce the side reactions caused by the methanogens.…”

“…Separators are normally anion exchange membranes (AEMs), cation exchange membranes (CEMs), bipolar membranes and charge‐mosaic membranes . The anode is the place where exoelectrogenic strains colonize the electrode surface to form an anode‐respiring biofilm . Electrogenic bacteria produce electrons, protons, and carbon dioxide (CO 2 ) through the biological oxidation of organic substance .…”

Improvement of the bioelectrochemical hydrogen production from food waste fermentation effluent using a novel start‐up strategy

“…8 Thus, proper selection of E an could better select exoelectrogenic bacteria at the time of colonization and better cause formation of the electroactive biofilm on the anode. 9 In a previous study with microbial fuel cells 10 it was observed that as the poised potential was increased, lag periods grew shorter (from 90 to 5 h, using an E an of 0.5 V vs Ag/AgCl). In addition, it has been observed 11 that the start-up time decreased (from 59 to 35 days) when an anodic positive poised potential was employed.…”

“…It has been reported that strains related to Geobacter have very different competitive advantages at different E an when they start in a mixed consortium as an inoculum . Thus, proper selection of E an could better select exoelectrogenic bacteria at the time of colonization and better cause formation of the electroactive biofilm on the anode …”

Single-chamber microbial electrochemical cell for CH4production from CO2utilizing a microbial consortium

“…1,2 Although CO 2 contains strong covalent bonds and is highly stable under most conditions, conversion of CO 2 to hydrocarbons has been reported by chemical, photochemical, electrochemical, and biological methods. 5 Microbial electrochemical cells (MECs) have been widely investigated for conversion of biological waste products into hydrogen, 6,7 where reduction reactions at the cathode involve combined electrochemical and microbial processes. However, many of these methods employ hydrogen as a reducing agent and might therefore not be economical.…”