Impacts of pH, temperature, and pretreatment method on biohydrogen production from organic wastes by sewage microflora

Biohydrogen production could be generated from organic wastes - food and beverage processing wastewater, restaurant food waste, and raw starch waste. Fermentative hydrogen production from food and beverage processing wastewater by sewage microflora was optimized in terms of pH (4.5 to 7.0), mesophilic condition (35°C ±2°C), and thermophilic condition (50°C ±2°C). Low initial pH (6.5) and mesophilic condition favored hydrogen production (0.28 L/L) indicating that such parameters along with the wastewater characteristics were crucial to dark-fermentative hydrogen production. Pretreatment methods (methanogenic inhibitor, sterilization, sonication, and acidification) on restaurant food waste and raw starch waste to enhance biohydrogen production were also investigated in this study. Maximum hydrogen yields of 3.48 ml H2/g COD and 2.18 ml H2/g COD were observed in sterilization of pretreated restaurant food and raw starch wastes, respectively.