Induced catabolic bio-electrohydrolysis of complex food waste by regulating external resistance for enhancing acidogenic biohydrogen production

A novel bio-electrohydrolysis system (BEH) based on self-inducing electrogenic activity was designed as pretreatment device to enhance biohydrogen (H2) production efficiency from food waste. Two-stage hybrid operation with hydrolysis in the initial stage and acidogenic fermentation of the resulting hydrolysate (after hydrolysis) for H2 production in the second stage was evaluated. Application of variable external resistances viz., 10 Ω, 100 Ω, 1000 Ω and closed circuit (CC) influenced the hydrolysis of substrate in BEH system and hydrogen production in acidogenic reactor compared to control. Pretreated substrate at 100 Ω documented higher H2 production (1.05 l) than 10 Ω (0.93 l), CC (0.91 l), 1000 Ω (0.88 l) and control operation (0.68 l). Comparatively, 10 Ω documented higher substrate degradation (53.4%) followed by CC (52.42%), 100 Ω (49.51%), 1000 Ω (47.57%) and control (43.68%). Voltammetric profiles were in agreement with the observed bio-electrohydrolysis and H2 production efficiency.