Due to the regionality and concentration of vegetable production, vegetable production bases, processing plants, transit transport stations and urban farmers' markets and other places produce a large amount of vegetable wastes. Vegetable wastes have high water content and organic matter content and are extremely perishable and are not suitable for mainstream treatment technologies such as landfill, incineration and other domestic wastes, however, this feature is suitable for anaerobic digestion treatment and thus biogas cleaning Energy, but also can use digested residue as organic fertilizer.The problem that needs to be faced in the process of anaerobic digestion is that the perishable and highly soluble carbohydrate content of vegetable wastes often leads to acidification, inhibition of methanogenic bacteria, Eventually resulting in anaerobic system instability and stop gas production, affecting the continuous and stable operation of biogas projects.
Based on this, the Chengdu Institute of Biology, Chinese Academy of Sciences, conducted a study on the temperature anaerobic digestion instability warning of vegetable wastes through the impact load test.Firstly, the liquid and gas phases of the vegetable wastes were anaerobically digested in anaerobic conditions, Parameters were dynamically and continuously monitored.Then, five second-order parameters were created on the basis of the first-order parameters.Finally, a total of 18 operating parameters were analyzed for their response acuity to load shocks, and the methane to carbon dioxide ratio (CH4 / CO2) (VFA / BA), propionic acid, n-butyric acid and isopentanoic acid were selected as early warning indicators for instability and the parameters of these five parameters Mild instability and severe instability warning threshold.The results show that the surface instability is mainly due to the lack of alkalinity of bicarbonate caused by the raw material characteristics of higher soluble carbohydrates and lower ammonia nitrogen and further buffer capacity of anaerobic digestive system In the opinion of the research team, we can increase the organic loading rate and the capacity of gas production in vegetable wastes by refluxing the biogas slurry, adding exogenous alkalinity or biogas promoter, etc. rate.
Relevant research results published in Bioresource Technology.The research has been funded by the National Natural Science Foundation of China, Chinese Academy of Sciences Green Council.
