The invention discloses a
biogas slurry ecological purification method based on microalgae cultivation. The method comprises the following steps: (1)
biogas slurry pretreatment; (2) habituated culture of autotrophic microalgae, namely, obtaining
algae strains capable of rapidly growing in 70%-100%
biogas slurry; (3) preparation of a seed solution; (4) a biogas slurry purification method during growing of microalgae, namely, after expanded cultivation, inoculating the habituated
algae species into an open
photobioreactor for cultivation, obtaining
chlorella biomass growing by
high density through a semi-continuous culture method and optimized methods such as fed-batch cultivation, and purifying the biogas slurry; (5) biochemical breaking of microalgae
cell walls, namely, introducing the microalgae cells into a biochemical wall breaking
pool, putting
freshwater fish into the
pool, and obtaining
algae slurry subjected to wall breaking; and (6) collection of the microalgae cells and recycling of the biogas slurry. According to the method, not only is a method provided for purifying the biogas slurry, but also the obtained algae cells and the biogas slurry can be recycled, so that ecologicalization treatment of the biogas slurry is realized, the environment is improved, and furthermore, the economic and
social benefits are produced.