Fermentative biohydrogen production from starch-containing textile wastewater

The present study deals with the biohydrogen production from starch-containing wastewater collected from the textile industry in Taiwan. The effects of inoculums collected from different sources (sewage sludge, soil and cow dung), substrate concentrations (5-25 g COD/L) and pH (4.0-8.0) on hydrogen production from wastewater were investigated. The cow dung seed had the highest hydrogen production of 101 mL with hydrogen content in biogas of 32.2%. It corresponds to a hydrogen yield (HY) of 1.56 mol H ₂/mol hexose and hydrogen production rate (HPR) of 0.93 L/L/d. Response surface methodology was used to evaluate the effects of initial cultivation pH (4.0-8.0) and substrate concentration (5-25 g COD/L) on the hydrogen production at 35 °C. At pH 7.0 with a wastewater concentration of 20 g COD/L, a maximum hydrogen production of 66 mL with 31.9% H ₂ and corresponding to an HY of 0.97 mol H ₂/mol hexose and an HPR of 1.14 L/L/d were obtained. According to the response surface analysis, the optimal conditions for high HPR were a wastewater concentration of 13 g COD/L at an initial cultivation pH of 7.0. The main soluble metabolic products were acetate and butyrate for hydrogen fermentation from textile wastewater.