Boosting biohydrogen production from pretreated sugarcane bagasse dust via coupled dark fermentation and microbial...

Lignocellulosic biomass is a promising feedstock for sustainable biohydrogen production; however, its application is limited by its low degradability and poor energy conversion efficiency. This study investigated whether integrating Dark Fermentation (DF) with a Microbial Electrolysis Cell (MEC), combined with effective pretreatment, can enhance biohydrogen recovery from sugarcane bagasse dust (SBD). Alkali and ultrasound pretreatment were employed to improve substrate digestibility, with structural changes confirmed by XRD and FTIR analysis. Pretreated bagasse produced 3.4 L/L (0.00608 mol H₂/g of dry substrate) of biohydrogen during DF, which was significantly higher than that produced by untreated substrate. The DF effluent was subsequently utilized in the MEC, where a maximum hydrogen yield of 0.9 L/L was achieved at an applied voltage of + 0.7 V. Enhanced biofilm formation under optimized anodic conditions in MEC was confirmed using Confocal Laser Scanning Microscopy (CLSM). The integrated DF-MEC system achieved 21% energy recovery, outperforming the single-stage DF (12.4%), thereby demonstrating the effectiveness of the combined approach.