Dairy cow solid waste hydrolysis and hydrogen/methane productions by anaerobic digestion technology

Abstract

Anaerobic batch fermenter was used to examine the biohydrogen production potential, the substrate was collected the hydrolysate from cow solid waste under the optimal hydrolysis conditions. The result showed that the hydrogen production yield of 97 ml H2/g cow solid waste were obtained by the regression of the experimental data and Gompertz equation.The optimal operating conditions of hydrolysis and hydrogen production were used to investigate the cultivation strategy in a continuous system. In the continuous biohydrogen reactor, pH and temperature values were controlled at 5.5 and 37 °C respectively. At hydraulic retention time (HRT) of 12 h, the average hydrogen production rate (HPR) was 150.59 ± 35.70 mL/l/d and the average hydrogen concentration was 41.01 ± 2.57%. In the continuous biomethane reactor, pH and temperature values were controlled at 7.0 and 55 °C respectively. At HRT of 72 h, the average methane production rate (MPR) was 395.41 ± 72.82 ml/l/d and the average methane concetration was 50.66 ± 2.86%.