Quick starting method for producing biogas through anaerobic fermentation of municipal sludge

Abstract

The invention relates to a quick starting method for producing biogas through anaerobic fermentation of municipal sludge. Anaerobic fermentation used as an effective recycling method is widely utilized in the world, but methanogens have high requirements in environment and are long in generation cycle, and according to the starting stage of an anaerobic digestion system, 3 to 8 months or even more time is usually needed. The invention provides the quick starting method according to the anaerobic fermentation of the municipal sludge, only 50 days is needed in the starting process, and the gas production and the content of methane are normal, and volatile fatty acids are prevented from being accumulated. The method comprises the specific steps of: adding anaerobic sludge used as inoculation sludge in an amount which is 10 to 15 percent based on the effective volume of an anaerobic reactor into the anaerobic reactor, feeding materials every day and not discharging, wherein according to a feeding strategy, effective microbial biomass of each day in the reactor is calculated, and starting a fermentation system every day in a feeding ratio, wherein the feeding ratio of matrix to the effective microbial biomass is always 10 percent. Experiments prove that by the method, the anaerobic reactor for the sludge can be quickly started.

Description

technical field [0001] The invention belongs to the field of solid waste recycling, and in particular relates to a quick start-up method for producing biogas by anaerobic fermentation of urban sludge. Background technique [0002] Urban sewage treatment plants produce a large amount of excess sludge due to the purification of domestic sewage. At present, the annual collection capacity is about 26 million tons (calculated at a moisture content of 80%). Sewage treatment plants mostly use sludge for treatment and disposal. The landfill method after concentration and dehydration not only occupies limited land resources, but also easily causes secondary pollution, which is not in line with the strategic principles of sustainable development in my country. In recent years, the global energy structure is undergoing a transition from fossil energy-based to the coexistence of multiple energy sources, and issues such as food security and environmental degradation have become increasing...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a kind of municipal sludge for the problems of difficult start-up, high start-up cost and long start-up period caused by the strict living environment of methanogens and high transportation cost of inoculum sludge during the start-up process of municipal sludge anaerobic fermentation. A quick start-up method for biogas production by anaerobic fermentation