Study On Characteristics And Anaerobic Digestion Performance Of Kitchen Waste

The living standard of the people, with the development of economy andcontinuously, increased in recent years, the number of kitchen waste rapid growth,which cause a series of problems of environmental pollution. As is known to all,kitchen waste as the main component of municipal waste with high-moisture andhigh-organic can through the anaerobic digestion to achieve the purpose of reductionand recycling, which produce clean energy of methane. This thesis mainly aims tokitchen waste and other solid waste materials hybrid anaerobic fermentation, findprocessing of kitchen waste, the optimum condition of the pilot test was carried outand further depth study of kitchen waste produce methane rule.This paper first for the determination of the physical and chemical properties ofkitchen waste, a full understanding on the basis of raw material composition, make thekitchen waste respectively with the maize straw, wheat straw, rice straw and chickenmanure, pig manure and sludge mixed anaerobic fermentation。each group offermentation raw materials in accordance with the mass ratio of1:9,3:7,5:5,7:3,9:1anaerobic fermentation, and monitoring the production rate of gas and productionrate of methane changes. Results showed that the quality of kitchen waste and sludgefor5:5has the best gas effect, cumulative production of methane up to9320mL.Kitchen waste and chicken manure groups’ gas effect is better, but the highestcumulative production of methane for8865mL, slightly lower than kitchen waste andsludge. kitchen waste and maize straw, wheat straw and rice straw to kitchen waste islower than and chicken manure, the highest cumulative production of methane ofthree groups respectively for7898mL and6517mL and6117mL. Kitchen waste andpig manure of gas effect is the worst, the matching group1:9,3:7failed to the normalstarting.Around the kitchen waste and sludge quality group, use the orthogonal test forfermentation process parameters optimization. Selected by using SPSS software fordata analysis conclusion: an optimum anaerobic digestion condition, mass ratio5:5, temperature50℃, pH value7, inoculums ratio40%, moisture content8%, The orderof influence factors on biogas production rate were: total solid content, temperature,mass ratio and inoculums rates.Use the laboratory CSTR reactor for verification test to further explorefermentation process of biogas production rules. Through continuous and sequencingbatch anaerobic fermentation, the anaerobic system within the pH value, VFA,ammonia nitrogen and alkalinity was monitored. Draw a conclusion that continuousway had small fluctuation change that continuous feed system has beenmethane-producing stable stage. Sequencing type monitoring results showed thatanaerobic digestion system fluctuation is bigger, pH value has been rising, to22dbasically stable; VFA concentration from high to low, from the fermentation of theearly2500mg/L descend to126mg/L; Ammonia nitrogen concentration in thefermentation of the highest in the middle of the2283mg/L, fermentation in early andlate concentration is low, the trend is down, after the first rise; Alkalinity of smallchanges, have been probably4000mg/L. The fluctuation of sequencing type showedthat the system has been to anaerobic environment and material regulate themetabolism, make the methane bacteria can better growth. The comparative analysisof the data, it is concluded that continuous type methane-producing system is stable,and the cumulative biogas production is sequencing batch type to1.4times.