Evaluation of various cheese whey treatment scenarios in single-chamber microbial electrolysis cells for improved biohydrogen production

Abstract

In this study single-chamber microbial electrolysis cells (MECs) were applied to treat cheese whey (CW), an industrial by-product, and recover H gas. Firstly, this substrate was fed directly to the MEC to get the initial feedback about its H generation potential. The results indicated that the direct application of CW requires an adequate pH control to realize bioelectrohydrogenesis and avoid operational failure due to the loss of bioanode activity. In the second part of the study, the effluents of anaerobic (methanogenic) digester and hydrogenogenic (dark fermentative H-producing) reactor utilizing the CW were tested in the MEC process (representing the concept of a two-stage technology). It turned out that the residue of the methanogenic reactor - with its relatively lower carbohydrate- and higher volatile fatty acid contents - was more suitable to produce hydrogen bioelectrochemically. The MEC operated with the dark fermentation effluent, containing a high portion of carbohydrates and low amount of organic acids, produced significant amount of undesired methane simultaneously with H. Overall, the best MEC behavior was attained using the effluent of the methanogenic reactor and therefore, considering a two-stage system, methanogenesis is an advisable pretreatment step for the acidic CW to enhance the H formation in complementary microbial electrohydrogenesis.

Managing the Effluents of Anaerobic Fermentations by Bioprocess Schemes Involving Membrane Bioreactors and Bio-Electrochemical Systems: A Mini-Review

“…The performance of a wide range of bioprocesses can be largely improved if hybridized with bio-electrochemical systems [58], as seen in Figure 8. Though MFCs could have the potential to process wastes of the food industry e.g., cheese whey [53], treatments prior to the bio-electrochemical systems may further improve their working efficiency on such substrates [54,55]. A cornerstone of wastewater e.g., fermentation effluent management in MFCs, is the electrical conductivity of the solution, which is often low and may reduce the power density.…”

Whey Utilisation: Sustainable Uses and Environmental Approach

“…They were also the first to report a strong influence of temperature on biohydrogen production, with the lowest temperature (15 °C) showing the best results (1.12 mol H 2 per mol lactose). Rivera et al ( 24 ) showed that microbial electrolysis cells can be considered for the treatment of cheese whey to obtain biohydrogen. Blanco et al ( 25 ) described the anaerobic structured-bed reactor (ASTBR) as a likely alternative for fermentative biohydrogen production from cheese whey, offering better performances than conventional fixed-bed reactors.…”

Whey Utilisation: Sustainable Uses and Environmental Approach

“…Rivera et al (24) showed that microbial electrolysis cells (MECs) can be considered for the treatment of cheese whey to obtain biohydrogen. Blanco et al (25) described the anaerobic structured-bed Please note that this is an unedited version of the manuscript that has been accepted for publication.…”