Kinetic analysis of biohydrogen production from complex dairy wastewater under optimized condition

Present work describes a kinetic analysis of various aspects of biohydrogen production in batch test using optimized conditions obtained previously. Monod model and Logistic equation have been used to find growth kinetic parameters in batch test under uncontrolled pH. The values of μm, Ks, and Xm were 0.64 h−1, 15.89 g-COD L−1, and 7.26 g-VSS L−1, respectively. Modified Leudeking-Piret and Michaelis-Menten equation corroborates a flux of energy to hydrogen production pathway and energy sufficiency in the system. Modified Gompertz equation illustrates that the overall rate and hydrogen yield at 15 g-COD L−1 was higher compared to a dark fermentation of other wastewaters. Besides, Andrew's equation also suggests that since the higher value of KI (19.95 g-COD L−1), k (255 mL h−1 L−1) was not inhibited at high S. The experimental results implied that the entire products during the fermentation process were growth and substrate degradation associated. The result also confirms that the acetate and butyrate were substantially used for hydrogen production in acidogenic metabolism under uncontrolled pH.