Effect of Dry Matter Concentration on Dry Anaerobic Digestion of Animal Manure and Straw

摘要

In this paper anaerobic digestion of dairy manure and straw was conducted to produce biogas. Under the conditions of C/N=25-30 and T=36°C, five kinds of dry matter concentration of 20%, 15%, 10%, 5% and 2.5% were tested to investigate the effect of dry matter concentration on anaerobic digestion. The result showed that first 30 days was the biogas production peak phase and VFA concentrations in the leachate were also high during the same period. When dry matter concentration increased, biogas production appeared larger fluctuation, and alkalinity and NH_4~+-N concentration in the leachate also increased with higher organic loading rate. Among five kinds of dry matter concentration, 10% was more suitable for anaerobic digestion to produce biogas with total biogas production amount of 4710 mL after 30 days and volumetric biogas yield of 0.313 m~3·m~(-3)·d~(-1). These results could provide instructive meaning to the engineering application of dry anaerobic digestion.