Bio-organic fertilizer preparation through extraction of biogas with slurry and then fermentation

The invention relates to the technical field of organic waste recycling and bio-fermentation and discloses bio-organic fertilizer preparation through extraction of biogas with slurry and then fermentation. The preparation includes the following steps: a) through a medium-temperature two-stage anaerobic digestion technology, feeding sludge and other organic wastes into a primary digestion tank according to a gas making and dewatering formula to extract majority of biogas and then continuously extracting the rest of the biogas in a secondary digestion tank; b) when the digestion reaction is finished, pumping the biogas slurry into a slope-type gravity automatic dewatering and sludge storing tank to automatically filter a part of water; and c) feeding the biogas slurry at the bottom of the tank into a stirrer, adding a dry powder material and bacteria strains according to a fertilizer making formula, stirring uniformly the mixture, feeding the mixture into a fermentation room and stacking the mixture into a windrow-like structure; d) with a windrow-type dynamic high-temperature fermentation technology, performing fermentation through a starting step, a high-temperature fermentation step and a post-treatment step to obtain a slurry material; and e) crushing and sieving the fermented slurry material to produce the organic fertilizer which is in conformity with national standard. The organic fertilizer can be applied in agriculture, forestry and aquatic product breeding industry.