Method for whole-process recycling of multiple biogas slurry components

Abstract

The invention discloses a method for whole-process recycling of multiple biogas slurry components and belongs to the technical field of environmental protection. The method comprises the following steps of pre-treating biogas slurry by struvite precipitation and flocculation, carrying out solid-liquid separation to obtain biogas residues, carrying out blending, granulation and drying of the biogas residues to obtain organic fertilizer particles satisfying the NY525-2012 ''organic fertilizer'' standard, disinfecting a clear liquid obtained by solid-liquid separation, adding nutrients into the disinfected clear liquid to obtain an alga medium, separating out cultured algae, carrying out washing, drying and crushing of the cultured algae to obtain protein feed satisfying a feed hygiene standard, adding nutrients into the remaining liquid as a liquid fertilizer production mother liquor obtained by alga separation, adjusting a pH value of the mixed liquid, and carrying out ultrafiltration to obtain a liquid fertilizer product satisfying the GB / T17419-1998 ''foliar microelement fertilizer'' standard. The method provided by the invention realizes comprehensive, efficient and integrated utilization of biogas slurry components. Through marketing or utilization, organic fertilizer particles, foliar fertilizer and protein feed prepared by the method further improve the income and a return rate of biogas engineering.

Description

technical field [0001] The invention belongs to the technical field of environmental protection, and in particular relates to a method for recycling biogas slurry in a multi-component whole process. Background technique [0002] At present, with the wide application of anaerobic fermentation biogas technology, biogas slurry is also produced in large quantities. Biogas slurry is the residue after anaerobic fermentation of various organic matter such as livestock and poultry manure, crop straw, and urban organic waste. How to dispose of biogas slurry efficiently and at low cost has become one of the urgent problems to be solved in biogas projects. Under normal circumstances, although biogas slurry can be directly applied to farmland as fertilizer, it needs to consider the season of fertilizer use and the carrying load of farmland. Once it is excessive, it will easily cause soil pollution and eutrophication of surrounding water bodies. If the biogas slurry is regarded as sewa...

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Problems solved by technology

[0003] In order to overcome the problems of high operating cost and low rate of return in the process of resource utilization of biogas slurry, the present invention provides a multi-component whole-process resource recovery method of biogas slurry, which realizes the comprehensive utilization of various components in biogas slurry , improve the rate of return of the biogas project, and avoid the risk of environmental pollution caused by the disorderly discharge of biogas slurry or unreasonable application

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