Study On Characteristics And Anaerobic Digestion Fermentation Of Municipal Sludge In Combination With Food Waste

Municipal sludge and food waste are solid waste with high utilization value.There anaerobic co-digestion can improve stability of the system, improve the organic matter degradation rate of substrate, and enhance the food waste anaerobic digestion in the industrialization’s feasibility to produce the biogas.This article carry through the food waste and municipal sludge mixed anaerobic co-digestion test. First choosed the municipal sludge and food waste mixing ratio, pH, temperature, the content of solid, and anaerobic digestion key factors to optimize, obtained the best gas production conditions. And then used the high temperature acidification way for the substrate pretreatment to investigate the gas production performance, methane, stability, and the digestion performance influence. At last, analyzed the gas production rate of municipal sludge and food waste anaerobic co-digestion and use of the black box material balance model to calculation the material balance.The main research results are as follows:1. The best process conditions of municipal sludge and food waste mix for anaerobic co-digestion as follows:the municipal sludge and food waste mixture ratio is40:60, adjusting the initial solid content is to15%, before digestion joining5g of sodium bicarbonate buffring, in the digestive process when pH less than6.5use20%of sodium hydroxide to adjust pH to7. Under high temperature oscillation digestion, its accumulation gas production can be up to11114ml, TS and VS removal rate respectively was to38.53%and56.01%. it is known that compared with the alone anaerobic digestion the municipal sludge and food waste mixed anaerobic co-digestion, can improve gas production and the degradation rate, besides the system has better stability.2. The results of high temperature of the acidification of anaerobic digestion effect on the performance show that:acidification can accelerate acidification of the organic matter hydrolysis, realize fast gas production of rush hour. The short time of high temperature acidification treatment have certain stimulative effect to the stability of producting methane; But, acidification process have accumulated a lot of volatile fatty acids, artificial adjusting the pH need more sodium hydroxide to guarantee the stability of the system.3. The experiment use of the black box material balance model. According to the municipal sludge and food waste’s TS rate is40:60calculated the theory of biogas is to54046.6ml,and the theory of average of CH4produced’s volume ratio is58.19%. Checked each experimental stage the gas production rate, the highest is to20.56%and the lowest is to3.35%. And checked the collection of the biogas rate under normal temperature the best digestive effect of municipal sludge and food waste with40:60TS ratio is to52.53%.