Anaerobic digestion biogas slurry vacuum concentration and recycling method and device

Abstract

The invention relates to the field of sewage treatment and discloses an anaerobic digestion biogas slurry vacuum concentration and recycling method. The anaerobic digestion biogas slurry vacuum concentration and recycling method comprises the following steps of feeding biogas slurry into a purification tower from an anaerobic digestion tank, performing heating and purification to convert liquid into secondary steam, and feeding the secondary steam into a defoaming tank for defoaming and then into a buffer tank; returning liquid in the buffer tank to the purification tower and gas into a biogasslurry cooler, and discharging condensate water in the biogas slurry cooler into a water seal tank; conveying water of the water seal tank to the anaerobic digestion tank as digestion supplementary water for recycling. According to the anaerobic digestion biogas slurry vacuum concentration and recycling method, the biogas slurry is concentrated at negative pressure, and the entire treatment process avoids destroying nutrients such as organic matters; the content of organic matters in the purified biogas slurry is higher than 65%, and accordingly the purified biogas slurry can be directly applied to farmlands; the condensate water collected in the water seal tank is 50-55 DEG C and contains less than 300 ppm of NH4-N, sulfide and the like, and when serving as the supplementary water of theanaerobic digestion tank, can keep constant temperature, shorten the liquidation and acid production time and improve the yield of biogas.

Description

technical field [0001] The invention relates to the field of sewage treatment, in particular to a treatment method for anaerobic fermentation biogas slurry. Background technique [0002] With the improvement of people's living standards in our country, the large-scale livestock and poultry breeding industry has developed rapidly and produced a large amount of breeding manure. At present, anaerobic fermentation process is mostly used in China to treat these manure, which effectively reduces the primary pollution of farm manure. But not all manure treated by anaerobic fermentation process can be fully utilized. Due to the different areas of the breeding sites, the treatment method that can completely consume the treated wastewater can only be applied to livestock and poultry sites with appropriate farmland, fish ponds or aquatic plant ponds around them, and the overall system arrangement of ecological agriculture environment. Most farms do not have sufficient conditions and ...

AI Technical Summary

Problems solved by technology

[0004] The technical problem to be solved by the present invention is to provide a method for vacuum concentration and recycling of anaerobic fermentation biogas slurry to solve the problem of low nutrient concentration in biogas slurry in the prior art, COD, SS, NH 4 -N and other problems that exceed the standard

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