Anaerobic Co-digestion Of Sewage Sludge And The Organic Fraction Of Municipal Solid Waste (OFMSW)

In China,anaerobic digestion?AD?is one of the main technical routes of sewage sludge?SS?disposal with many problems such as high yield and low organic matter content.Meanwhile,organic parts of municipal solid waste?OFMSW?have high methane potential due to high organic content.Therefore,in this study,anaerobic co-digestion of SS and OFMSW was conducted,and lignocellulosic biomass?LB?,food waste?FW?and kitchen lipids?KL?were used to co-substrate,whose production is large in Chongqing.The effect of Characteristics of the feedstock components and addition ration?on VS basis?on methane production were analyzed,and stability,inhibited factor and microbial community diversity of AcoD were evaluated.For AD of SS,AcoD of SS and plant residue,AcoD of SS and bagasse residue and AcoD of SS and medicine residue,the specific biogas yield?SBY?were 120.1?273.3?230.7?251.2 mL/VS_added,the specific methane yield?SMY?were 88.1?161.1?132.3?143.4 mL/VS_added,and volatile soilds?VS?removal were 33.28%?46.72%?43.04%?45.04%.Based on 16S rDNA sequencing technology,the relative abundance of acetate-utilizing methanogen?Methanosaeta?were 9.01%,3.52%,3.69%and 4.09%respectively.AcoD of SS and KL which mixed with plant residue was conducted,and there was highest methane production at the ratio of 1:2:1?on VS basis?with higher biodegradability and shorter lag time.The SBY and SMY were were 500.4 mL/gVS_addeddded and 341.5 mL/gVS_added respectively,Furthermore,the digester stability was observed,and here was no acidification,as while as ammonia nitrogen and free ammonia had no inhibitory effect on the digester.The addition of plant residue promotes the activity of cellulase.The relative abundance of acetate-utilizing methanogen?Methanosaeta?in AcoD digester was higher than that in mono-digestion digester.Similarly,AcoD of SS and FW which mixed with plant residue was conducted,and there was highest methane production at the ratio of 2:1:0.5?on VS basis?with higher biodegradability and buffer ability.The SBY and SMY were were 500.4 mL/gVS_addeddded and 341.5 mL/gVS_added respectively.The highest content of CH₄ and H₂S were71.37%and 189.85ppm.The addition of KL improve the risk of acidification and electrical conductivity in digester,as while as ammonia nitrogen and free ammonia had no inhibitory effect on the digester.Furthermore,the relative abundance of acetate-utilizing methanogen?Methanosaeta?in AcoD digester was higher than that in mono-digestion digester.