Cogeneration of hydrogen and lipid from stimulated food waste in an integrated dark fermentative and microalgal bioreactor.

ABSTRACT

In this study, a novel integrated dark fermentative and microalgal bioreactor (IDFMB) was developed to simultaneously produce H2 and lipid from food waste. Under the optimized working volume ratio of 14, starch concentration of 7 g L-1 and initial pH of 7.0, the highest H2 production of 1643.5 mL L-1 and lipid yield of 515.6 mg L-1 were achieved. Microalgae can effectively utilize the main end products in dark fermentative effluent (acetic acid and butyric acid) for cell growth and lipid accumulation. Compared with single dark fermentation, the energy conversion efficiency from stimulated food waste was significantly enhanced by the IDFMB, which increased from 14.8% to 35%. Microbial community analysis revealed that Clostridium was the dominant bacteria for H2 generation, and the IDFMB can improve the survival environment of microorganisms. This study provides a novel strategy for efficient energy recovery from food waste.