Method and device for vacuum concentration and recycling of biogas slurry

Abstract

The invention relates to the field of sewage treatment, and discloses a method for vacuum concentration and recycling of biogas slurry. The method includes the following steps: adding biogas slurry from an anaerobic fermentation tank into a purification tower, heating and purifying to convert liquid into secondary steam, wherein the secondary steam enters a defoaming tank for defoaming, and then enters a buffer tank; returning, by the liquid in the buffer tank, to the purification tower, feeding the gas in a biogas slurry cooler, and feeding condensed water from the biogas slurry cooler in a water sealing pool; transferring the water in the water seal pool to the anaerobic fermentation tank by a transfer pump to be circulated as fermentation supplement water. According to the method, the biogas slurry is concentrated under negative pressure, nutrient substances such as organic matters and the like are not damaged in the whole treatment process, the organic matter content in the obtained pure biogas slurry is more than 65%, and the pure biogas slurry is directly used in farmland, the temperature of the condensed water collected in the water sealing pool is 50-55 DEG C, the content of NH4-N, sulfide and the like, and volatile substances are less than 300 ppm, and the temperature of the anaerobic fermentation tank is kept constant as supplementary water of the anaerobic fermentation tank, so that the time for liquefaction and acid production is shortened, and the gas production efficiency is improved.

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 biogas slurry, which solves the problem of low nutrient concentration in biogas slurry in the prior art, COD, SS, NH 4 -Exceeding the standard such as N

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