| With the rapid development of society and changes in people’s lifestyles,food waste has gradually become an important part of urban solid waste.It contains rich organic substances and can be used as an ideal substrate for resource utilization,but due to its complex composition and contains high oil,high salt,the characteristics lead to low processing efficiency,so exploring efficient food waste treatment technology has become a new hotspot in the environmental field.Anaerobic fermentation can not only convert food waste into clean energy-methane,but also produce biogas slurry and biogas residue with rich nutrients.It is a treatment technology that integrates resource and economic benefits.Based on a new type of anaerobic fermentation process-Leachate Bed Reactor(LBR,Leachate Bed Reactor),this paper uses batch experiments to compare the anaerobic fermentation effect of food waste under different temperature and medium material conditions to determine the best optimal fermentation conditions;Through analysis of the microbial community structure to reveal its relationship with fermentation efficiency,and make analysis of the anaerobic fermentation control strategy;through the pot experiment of Chinese cabbage to study the effects of food waste biogas residue on Chinese cabbage and soil,Explore the feasibility of biogas residue utilization.A batch test was used to compare the effects of adding different media materials-corn stalk and charcoal on the methanogenic capacity of anaerobic fermentation of food waste at room temperature and medium temperature.It was found that: at medium temperature(35°C),the best methanogenic effect was obtained by adding straw to the food waste.The volume fraction of methane was as high as 68.92% in the whole reaction cycle,the cumulative methane production reached 19.56 L,and the average methane production The rate was 97.7 m L CH4/g TS.The concentration of COD and VFA in the leachate also showed a significant downward trend during the reaction,reaching the lowest values at the end of the reaction,which were 15.6 g/L and 11.4 g/L,respectively.Moreover,the biogas residue obtained by the reaction under this condition has a good shape,a loose and uniform structure.By analyzing the microbial community structure in the LBR reactor under the best matching conditions of temperature and medium materials,it was found that LBR’s unique structure of upper solid and lower liquid contributes to the functional differentiation and enrichment of anaerobic bacteria in the reactor.The upper part of the reactor is enriched with a large number of bacteria related to the hydrolysis and acidification process,and the lower part is richer in the bacteria group related to the hydrogen and acetic acid production process.The addition of straw promotes the increase in the abundance of Firmicutes(thick-walled bacteria),which is more conducive to carbon water Degradation of compounds and fibres.The medium temperature(35°C)is more conducive to the growth of methanogenic archaea,and its species abundance and diversity have been significantly improved,enhancing the stability of the methanogenic system.The composition and physicochemical properties of food waste biogas residue were analyzed,and the biogas residue was used to test the cultivation of Chinese cabbage,and the effects of biogas residue on the growth and quality of Chinese cabbage and soil enzyme activity were investigated.The results show that different methods of fertilization of biogas residue can promote the quality of Chinese cabbage and the activity of urease and sucrase in soil.Among them,the combined application of biogas residue and inorganic fertilizer has no inhibitory effect on the germination rate of Chinese cabbage,and has increased the plant height and average yield of single Chinese cabbage;it has also increased the content of vitamin C,soluble sugar and chlorophyll in Chinese cabbage,Reducing the accumulation of nitrate content is beneficial to the improvement of Chinese cabbage’s quality. |
PDF Full Text Request