Study of the performance of biogas production by mixed fermentation of cow dung, deer manure, and mushroom fungus

Abstract Anaerobic digestion (AD) of livestock and poultry manure to produce biogas can not only improve environmental problems, but also effectively utilize waste. In order to maximize the resource utilization of livestock and poultry manure, the AD experiments of mixing cow dung, deer manure, and mushroom fungus were carried out. The changes of AD biogas production (daily and cumulative biogas production), CH 4 content, volatile fatty acids (VFAs), pH at different temperatures (20, 35, and 50°C), and mixing ratios were studied, and the optimum reaction conditions were discussed. Results show that with the increase in temperature the biogas production rate and the cumulative biogas production at each proportions increase. At 20°C, the amount of biogas generated is very small. Under different proportions of raw materials, the cumulative biogas production first increased and then decreased. The best biogas production is at a temperature of 50°C and a proportion of cow dung, deer manure, and mushroom fungus is 0.3:0.4:0.3. The unit total solid biogas production rate reached 0.23 L·g −1 . The mixed fermentation of livestock manure and mushroom fungus made up for the inadequacy of its separate fermentation performance and was also an effective method to improve the biogas rate and comprehensive utilization rate of livestock manure. The results of this study are of great significance in promoting the utilization of livestock and poultry manure.