Treatment method of biogas liquid

Abstract

The invention provides a treatment method of biogas liquid. According to the treatment method, after the pH (potential of Hydrogen) value of original biogas liquid is adjusted, ammonia nitrogen in the biogas liquid is subjected to preliminary recovery by adopting acidic absorption liquid through a way of absorption by a hollow fibrous membrane component; afterwards, the biogas liquid obtained by contact absorption is subjected to an anaerobic reaction, a facultative reaction and an aerobic reaction in sequence. By using the method provided by the invention, the ammonia nitrogen in the biogas liquid can be converted into an ammonium salt to carry out recycling; the concentration of the ammonia nitrogen in the biogas liquid is decreased; the subsequent biological denitrification and dephosphorization are facilitated. The treatment method is simple in process and low in cost. In the method provided by the invention, the concentration of the ammonia nitrogen in the biogas liquid subjected to the contact absorption is decreased to 20mg / L to 50mg / L; in the biogas liquid subjected to whole-course treatment, the TP (Total Phosphorus) index is 6mg / L to 8mg / L, the concentration of the ammonia nitrogen is 10mg / L to 30mg / L, the COD (Chemical Oxygen Demand) is 50mg / L to 220mg / L, and the pH value is 7 to 9; the national Discharge Standard of Pollutants for Livestock and Poultry Industry (GB18596-2001) is met.

Description

technical field [0001] The invention relates to the technical field of biogas slurry treatment for livestock and poultry breeding, in particular to a treatment method for biogas slurry. Background technique [0002] Livestock and poultry farms mostly adopt the ecological model of raising-biogas-irrigation: the wastewater generated by breeding is treated by anaerobic fermentation to produce biogas slurry containing a large amount of ammonia nitrogen, phosphorus and organic matter, and the obtained biogas slurry is used in the farmland near the farm fertilization. [0003] In recent years, with the continuous expansion of the breeding scale, the amount of biogas slurry produced is increasing. However, most of the farms are located in remote mountainous areas with a small number of farmers. In addition, the concentration of fertilizer substances in the biogas slurry is thin and the transportation is difficult. As a result, a large amount of biogas slurry is not comprehensively...

AI Technical Summary

Problems solved by technology

However, most of the farms are located in remote mountainous areas with a small number of farmers. In addition, the concentration of fertilizer substances in the biogas slurry is thin and the transportation is difficult. As a result, a large amount of biogas slurry is not comprehensively utilized, and it is discharged to the waters near the farm without treatment, which has a negative impact on the local water body. cause serious pollution

According to the survey data disclosed by the Ministry of Environmental Protection, 90% of the large-scale livestock and poultry farms have not carried out environmental impact assessment, and 60% of the farms lack the necessary biogas slurry pollution prevention and control measures

[0004] At present, there are two main methods for treating biogas slurry in the market: one is to concentrate the biogas slurry to improve its fertilizer efficiency; the reverse osmosis membrane concentration method is used, but complex pre-treatment is required, and the treatment cost is too high; the other One is to use the biological treatment method to convert all ammonia nitrogen into nitrogen discharge. This process does not make use of ammonia nitrogen. At the same time, due to the high concentration of ammonia nitrogen, the concentration of ammonia nitrogen after treatment does not meet the relevant discharge standards.

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