Bio-hydrogen production from apple waste by photosynthetic bacteria HAU-M1

• The feasibility of rotten apple's efficient utilization was analysed.
• Effects of process parameters on hydrogen production with high-efficient photosynthetic bacteria HAU-M1 were investigated.
• Response surface methodology was used to optimize hydrogen production.
• Regression equations were established to analysis hydrogen production.

Huge amounts of rotten apples are generated in China, the biggest apple producer in the world. Bio-hydrogen production from apple waste is a promising strategy to treat this biomass waste, while producing hydrogen as renewable energy. In this study, apple waste was taken as a carbon source for bio-hydrogen production from high-efficient photosynthetic bacteria (PSB) HAU-M1. Effect of initial pH, light intensity, temperature and material to liquid ratio on the hydrogen production by HAU-M1 was evaluated using both single-factor design and response surface methodology (RSM). The optimal conditions were initial pH of 7.14, light intensity of 3029.67 lx, temperature of 30.46 °C, and material to liquid ratio of 0.21, respectively. A maximum specific hydrogen yield (SHY) of 111.85 ± 1 mL H2/g TS was obtained under the optimal conditions. In apple-production countries such as China, the success of hydrogen production from apple waste by PSB demonstrated a great application prospect on sustainable utilization of apple waste.