| As an important part of municipal solid waste,kitchen waste accounts for an increasing proportion of municipal solid waste in recent years.Anaerobic fermentation technology can use kitchen waste to produce green renewable energy-methane,and effectively reduce the production and accumulation of kitchen waste and reduce its pollution to the environment.The content of easily degradable organic matter in kitchen waste is high,which makes the anaerobic fermentation process of high concentration kitchen waste easy to lead to poor or even failure of process operation due to the accumulation of volatile fatty acids in intermediate products.If other substrates are added to the anaerobic fermentation system of kitchen waste to regulate the carbon-nitrogen ratio,the accumulation of organic acids can be reduced to a certain extent,the production efficiency of methane will be improved,and the continuous operation of the system will be guaranteed.Chicken manure contains high concentration of protein and ammonia nitrogen,mixed fermentation with kitchen waste is beneficial to improve the cushioning ability of anaerobic fermentation reaction system to volatile fatty acids.The source of inoculated mud was determined by preliminary test and domesticated.After the domestication of inoculation mud was completed,the semi-continuous medium temperature test of mixed fermentation of kitchen waste and chicken manure was carried out,the details were as follows:(1)The types of sludge inoculated in anaerobic fermentation process were determined and the laws of the early stage of inoculation sludge domestication were studied.First,a batch anaerobic fermentation experiment was carried out,and the mud in anaerobic digestive pool of sludge was determined as inoculation mud according to the results of gas production and the change of p H value.Then a multi-batch fermentation experiment was carried out to study the characteristics of the gas production capacity of the inoculated sludge,and the cumulative methane yield of each batch was fitted dynamically.With the increase of domesticated batches,the delay period of methane production by inoculation is gradually shortened,the rate of methane production increases gradually,and the degree of acidification decreases gradually in each batch,and the experimental results show that the adaptability of inoculation mud to substrates increases gradually.(2)A semi-continuous medium temperature test was carried out for the mixed fermentation of kitchen waste and chicken manure,and the cushioning capacity of the kitchen waste fermentation system was improved by adding a small amount of chicken manure(VS15%),and the organic load rate(OLR)was gradually increased during the long-term operation of the fermentation system.Further domestication and improve the ability of fermentation system to adapt to high-load substrates.The results showed that the hydraulic residence time(HRT)was 30 d and the substrate concentration increased from 30g-VS/L to210g-VS/L,that is,when the corresponding OLR gradually increased from 1g-VS/L/d to7g-VS/L/d,the removal rate of volatile solids(VS)in the system remained at about 90%,The concentration of ammonia nitrogen remained within 1500mg-N/L,the p H was maintained in the 7.0~8.0 range,and the average methane yield of the average daily methane production from 922.13 m L to 9199.36 ML,OLR gradually increased was roughly the same,remaining at220 m L/g-VS,The average methane yield in the next 3 stages gradually increased to350 m L/g-VS,and the mixed anaerobic fermentation reactor of chicken manure and kitchen waste continued and stabilized the operation of real estate gas under high load. |
PDF Full Text Request