Parameters Optimization of two-phase united anaerobic fermentation hydrogen-methane production

The two-phase united anaerobic fermentation has been paid more and more attention in recent years. But how to increase the biogas production yield and the degradation rate of organic matter needs more research. The batch anaerobic fermentation studies demonstrated the feasibility of H-2 and CH4 generation utilizing kitchen wastewater as substrate, and the vaccination rate, dilution rate, substrate concentration were optimized. The conclusion showed that dilution rate is the most important factor, following by kitchen wastewater concentration and inoculum volume. The most excellent program of the organic load, the inoculation volume and the dilution volume are 150 +300 ml, 135 ml, 225 ml, respectively. Under these conditions the hydrogen and methane production rate were the highest of 4.15 ml/ml, 2.55 ml/ml (calculated as the wastewater volume), respectively. The acid-forming pathways of kitchen wastewater was typical butyric- propionic acid mixed fermentation type. The appropriate dilution could decrease the concentration of the total acids and increase the biogas production yield.