Method for improving methane yield of primary sludge through utilizing expanded granular sludge bed

Abstract

The invention belongs to the technical field of environmental protection, and in particular relates to a method for improving the methane yield of primary sludge through utilizing an expanded granular sludge bed. The method comprises the specific steps of: firstly carrying out anaerobic hydrolysis acidification on the primary sludge under the alkaline condition so as to obtain supernatant liquor which contains a great quantity of short-chain fatty acids, and then, feeding the supernatant liquor into the expanded granular sludge bed (EGSB) to efficiently and continuously generate methane. The hydrolysis and acid production rate of non-soluble organic matters (such as protein and carbohydrate) in the primary sludge can be increased, so that more short-chain fatty acids are obtained, and moreover, the organic matters can be efficiently converted into the methane in the EGSB, thus the environmental pollution of the sludge is reduced. According to the method, the pH value of the primary sludge is regulated to be 8-12, the primary sludge is stirred at 30-40 DEG C for 6-10 days to be anaerobically fermented, the supernatant liquor of the primary sludge is collected, and the pH value of the supernatant liquor is regulated to be 6-8; and then, the supernatant liquor is filled into the EGSB to be fermented, the methane is anaerobically generated under the intermediate temperature anaerobic fermentation condition of 33-37 DEG C and the organic load (the organic matter removal amount in a unit time per unit volume of the bed) of 5-45kg COD (chemical oxygen demand) / m<3> / d.

Description

technical field [0001] The invention belongs to the technical field of environmental protection, and in particular relates to a method for improving the methane production rate of primary sludge by using an anaerobic expansion layer reactor. Background technique [0002] Biological treatment of sewage and wastewater will produce a large amount of waste sludge, which will cause secondary pollution to the environment if the waste sludge is not properly disposed of. Using anaerobic biological method to treat organic solid waste or sludge can not only reduce environmental pollution, but also obtain clean energy such as methane (Environ. Sci. Technol. 1986, 20, 1200-1206). Anaerobic biological treatment of sludge is usually divided into four stages: hydrolysis stage, acid production stage, acetogenic stage, and methanogenic stage. The hydrolysis stage of non-dissolved organic substances (such as protein and polysaccharides) in sludge is considered to be the rate-limiting step in...

AI Technical Summary

Problems solved by technology

[0003] Although some high-efficiency anaerobic reactors such as the anaerobic expanded bed reactor (EGSB) have been developed and applied to organic wastewater for methane production, there are few reports on the application of these high-efficiency anaerobic reactors to the anaerobic production of primary sludge. methane process