Bio-electrohydrolysis as a pretreatment strategy to catabolize complex food waste in closed circuitry: Function of electron flux to enhance acidogenic biohydrogen production

A novel bio-electrohydrolysis system (BEH) based on self-inducing electrogenic activity was designed as a pretreatment device to enhance biohydrogen (H-2) production efficiency of food waste. Experimental strategy involved two-stage integrated/hybrid operation with hydrolysis in initial stage followed by acidogenic fermentation for H-2 production in second stage. After pre-treatment, catabolized food waste from control (anaerobic) and BEH (closed circuit mode of operation) system was used as substrate in a separate bioreactor to evaluate H-2 production in dark-fermentation process. Pretreated-waste from BEH showed higher H-2 production (29.12 ml/h; 24th h) than control (26.75 ml/h; 16th h). Higher cumulative H-2 production and maximum substrate degradation were also noticed with BEH-pretreated substrate (CHP, 0.91 l; COD, 52.42%) than control (CHP, 0.68 l; COD, 43.68%). Under closed circuitry, anode served as an alternative electron acceptor promoting biotransformation of complex organics to simpler molecules through catabolism. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.