Impact of Inoculum Concentration on Anaerobic Co-digestion of Swine Manure and Rice Straw

Taking biogas slurry as inoculum,the performance of biogas production for dry anaerobic co-digestion of swine manure and rice straw with the inoculum concentration based on TS of inoculum and feedstock of 1.2 %,2.4% and 4.8% was studied,and the changes of daily biogas production,cumulative biogas production,methane content,p H,TS,SCOD during digestion were analyzed. Results showed that,each treatment had two biogas production peaks in the digestion process and the treatments with biogas slurry inoculum achieved the second peak 12 days earlier than the CK. The biogas yield of the treatment with the inoculum concentration of 1.2% could reach 315 m L/g-TS,which was 6.06%,11.31%,3.62% higher than the treatments of the CK,the inoculum concentration of 2.4% and 4.8% respectively. The methane content in all treatments could achieve more than 80% during the stable stage of digestion. Appropriate amount of inoculum could improve biogas yield,heighten biogas production peak and accelerate biogas production,but had no significant effect on cumulative biogas production.