Method for resource utilization of kitchen garbage anaerobic fermentation liquor

Abstract

The invention discloses a method for resource utilization of kitchen waste anaerobic fermentation broth, which is characterized by comprising the following steps: step 1, removing large-particle solids from the kitchen waste anaerobic fermentation broth to be treated through a simplified pretreatment process, thereby improving the treatment efficiency and reducing the energy consumption to obtain treated liquid; step 2, performing an electrodialysis process on the treated liquid by using an electrodialysis system to realize synchronous desalination and denitrification to obtain a concentrated solution and a desalted and denitrified fermentation solution; 3, maintaining the performance of an ion exchange membrane of the electrodialysis system through regular electrode reversing and chemical cleaning; and step 4, realizing resource utilization of the separated concentrated solution and the desalted and denitrified fermentation liquor.

Description

technical field [0001] The invention relates to the field of resource utilization of kitchen waste, in particular to a method for resource utilization of anaerobic fermentation liquid of kitchen waste. Background technique [0002] After the implementation of garbage classification in our country, a large amount of kitchen waste is sorted out, which is mainly treated by anaerobic digestion. How to recycle the resulting large amount of biogas slurry is becoming a bottleneck in the promotion of anaerobic digestion technology. The anaerobic fermentation liquid of kitchen waste is rich in N, P and organic matter. Returning to the field can provide a resource utilization outlet for the biogas slurry produced in large quantities. The rich nutrients in the biogas slurry are easily absorbed and utilized by plants, which can reduce the use of chemical fertilizers , to effectively reduce carbon emissions in the fertilizer production process; at the same time, the study in the "Effect ...

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Problems solved by technology

However, the concentration of ammonia nitrogen in the biogas slurry is very high, which brings great treatment pressure to the sewage treatment plant. The high N content requires a very high carbon source cost in the denitrification process of the sewage treatment plant, which not only makes the rich nutrient resources not effectively utilized. , also resulting in a very high processing cost input

[0004] In view of the above problems, the existing method proposes to use electrodialysis to separate and concentrate the nutrients in the biogas slurry. Chinese patent CN112499846A discloses a method for the concentration and recovery of nutrients in biogas slurry. Chinese patent CN112520915A discloses a synchronous An anode electrodialysis method for recovering nitrogen and phosphorus in biogas slurry and removing antibiotics, separating N, P, and K in biogas slurry in order to use the concentrate as fertilizer, but this treatment method has several obvious disadvantages: First, electrodialysis The process has no selectivity for ions, and the salt is also concentrated when the nutrients are concentrated, and the concentrated solution is used as a fertilizer with a higher risk of salinization; second, this method all advocates pretreatment by membrane filtration to remove suspended solids in the biogas slurry. Including microfiltration, ultrafiltration or nanofiltration, and then electrodialysis, but the actual situation is that the biogas slurry contains a large number of suspended particles such as colloids with diameters in the micron range, which can easily cause filter membrane blockage, and large-flux membrane filtration pretreatment It is difficult to realize; the third is that this kind of method pays more attention to how to use the separated N and P, but completely ignores how to deal with and utilize the remaining fermentation liquid; the fourth is that the biogas slurry often only refers to the decomposed organic matter mainly composed of humic substances. Biogas slurry, not involving fresh fermentation broth mainly composed of organic acids

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