A method for improving the efficiency of sludge anaerobic digestion while reducing the ecotoxicity of heavy metals

Abstract

The invention relates to a method for simultaneously improving sludge anaerobic digestion efficiency and reducing the ecotoxicity of heavy metals. According to the method, after straws are activated with a ZnCl2 solution, straw biochar is prepared under a 550 DEG C high-temperature anaerobic condition, and further modification is performed by using an HCl solution and microwave; and by using modified biochar as carrier, a zero-valent nano-iron loaded modified biochar composite material HCl-FBC is prepared through a chemical reaction. According to the present invention, by adding the modified biochar composite HCl-FBC to the anaerobic digestion reactor at the initial stage of sludge anaerobic digestion, the organic matter conversion rate of sludge can be significantly increased, and the cumulative gas production of methane can be increased; HCl-FBC can easily increase the microbial diversity and the activity of the digested sludge and change the microbial community structure; and with the method, the sludge anaerobic digestion efficiency can be significant increased, the biogas production can be increased, the biological toxicity of the heavy metal in the digested sludge is effectively reduced, and the great significance is provided in the resource utilization of sludge and the reduction of the risk of sludge land use.

Description

technical field [0001] The invention relates to the field of solid waste recycling, in particular to synthesizing a functional material of modified sludge biomass charcoal loaded with zero-valent nano-iron particles, and studying the stability of sludge anaerobic digestion process by adding modified biomass charcoal composite materials In particular, it involves the use of biochar composites to increase the cumulative yield of methane from anaerobic digestion and reduce the ecotoxicity of heavy metals. Background technique [0002] With the continuous improvement of my country's sewage treatment capacity, a large amount of sludge is produced and accumulated in the environment as a by-product of the sewage treatment process. In recent years, an average of more than 25 million tons of sludge (80% water content) is produced every year. If not handled properly, it will cause serious pollution to the environment. Sludge is rich in organic matter that can be used as a resource an...

AI Technical Summary

Problems solved by technology

CN107892929A provides a method for preparing iron sulfide modified sludge-based biochar, the iron sulfide loaded on the biochar is nano iron sulfide or micron iron sulfide; CN107930629A provides a preparation method for loaded biochar catalytic material , in a nitrogen environment, the mass ratio of Fe to biochar is not less than 1:1, but these two technologies have not been further modified after biochar preparation, making their treatment efficiency low

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