Synergistic sodium alginate- and biochar-immobilized cells for enhancing fermentative hydrogen production from food...

An immobilized hydrogen-producing consortium investigated biohydrogen production from food waste using a combination of sodium alginate and cassava rhizome biochar. We investigated the effect of varying the biochar concentration from 0 to 3% and the size of immobilized cells from 1 to 7 mm. Immobilized cells were prepared using 50% (v/v) enriched hydrogen-producing consortium, 2% (w/v) sodium alginate, and 0 to 3% (w/v) cassava rhizome biochar. The optimal conditions for achieving the highest hydrogen production in the batch fermentation reactor were identified as a biochar concentration of 2% (w/v) and an immobilized cell size of 2 mm. The highest hydrogen yield, maximum hydrogen production rate, and lag time recorded were 0.69 mmol H₂/g-COD, 0.02 mmol H₂/g-COD.h, and 41.51 h, respectively. This research highlights the potential of cassava biochar technology for efficient biohydrogen production from food waste, contributing to renewable energy generation and sustainable waste management.