Method for enhancing anaerobic digestion and methane production of excess sludge by zero-valent iron and activated carbon

Abstract

The invention belongs to the technical field of sludge treatment and recycling and discloses a method for enhancing anaerobic digestion and methane production of excess sludge by zero-valent iron and activated carbon. The method comprises steps as follows: (1), the excess sludge, inoculated sludge and water are mixed, pH is regulated to 6-7.5, solid content of a mixture is enabled to be 8%-12%, and mixed sludge is obtained; (2), the mixed sludge, activated carbon and zero-valent iron are added to an anaerobic digestion device, and anaerobic digestion is implemented; (3), gas produced in the anaerobic digestion process is collected. According to the method, the anaerobic digestion is better promoted by adding activated carbon and zero-valent iron simultaneously; the method is simple, reaction conditions are mild, a gas producing effect is better than that of a traditional method, recycling, harmless and reducing treatment of the excess sludge of a sewage treatment plant is realized, and the method has good economic and social benefits.

Description

technical field [0001] The invention belongs to the technical field of sludge treatment and resource utilization, and relates to a method for simultaneously adding zero-valent iron and activated carbon to strengthen anaerobic digestion of excess sludge to produce methane. Background technique [0002] Due to the increase in the number of urban sewage plants and the increase in the amount of sewage treatment, the amount of surplus sludge produced by the activated sludge process is also increasing. The total amount of dry sludge in EU countries has reached more than 10 million tons per year. In China, more than 11.2 million tons of dewatered sludge are produced every year, and nearly 80% of them have not been stably treated, and the annual growth rate is greater than 10%. The excess sludge produced contains a large amount of organic matter such as protein, polysaccharide, etc. Direct discharge will not only cause secondary pollution of the environment, but also cause a large a...

AI Technical Summary

Problems solved by technology

Anaerobic digestion of high-solids sludge is a research hotspot at the present stage. Its advantage is that it can effectively reduce the reaction volume of the anaerobic digester and increase the concentration of organic matter. However, there are still many problems, such as inhibition of ammonia nitrogen, low degradation rate of organic matter, production The disadvantages such as low methane efficiency limit the promotion and application of this technology

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