The Resource Utilization Method Of The Biogas Slurry In The Farm Under The Co-Processing Of Fungi And Microalgae

With the increasing intensification of the livestock and poultry breeding industry in my country,the scale of farms and the scale of biogas projects built are getting larger and larger,and more and more biogas slurry is produced.The composition,color and nutrition of the biogas slurry are complex.It has high concentration and poor biochemical properties.If it is not properly treated,it will inevitably cause secondary pollution in the process of resource utilization of manure.However,the currently used biogas slurry treatment technology has complicated operations,high energy consumption,and high cost,and it is difficult to meet the requirements of engineering applications.Therefore,it is urgent to develop a high-efficiency biogas slurry deep purification process.This project mainly explores the potential of biogas slurry as a culture medium for microalgae,explores its biomass accumulation in the biogas slurry,researches the key influencing factors and control methods of microalgae cultivation in the biogas slurry,and realizes the treatment of biogas slurry and microalgae biomass resources The dual effect of chemical utilization.The main work and test results are as follows:The results of experiments on algae cultivation after pretreatment of biogas slurry by physical methods found that:Chlorella sp.was cultured in the biogas slurry pretreated by three physical methods:dilution,filtration,and sedimentation.The biomass changes were continuously measured.The results showed that Chlorella sp.was only at low levels.It grows well in the concentrated biogas slurry.Under low dilution(dilution 13 times and 10 times)and natural sedimentation conditions,the biomass of chlorella gradually decreases with time.Under filtration conditions,the growth of chlorella tends to decrease firstly.Chlorella sp.is not very adaptable to biogas slurry,and other pretreatment methods need to be explored.The results of screening,isolation and identification of fungi found that:a strain with good decolorization effect on biogas slurry was screened.This strain was identified as Aspergillus fumigatus and named NCU-21.The experiment proved that the strain has a good decolorization effect on biogas slurry The decolorization rate of the biogas slurry is 53%after 24h cultivation on the biogas slurry medium with a concentration of 10%.The optimization experiment of the fungal treatment biogas slurry conditions showed that the best p H of the biogas slurry treatment with this strain was 6,the best inoculum amount was 1×10~6/ml,the best cultivation temperature was 30℃,and the best biogas slurry concentration was 10%.The optimal amount of glucose added is 1 g/L.The results of the study on fungal treatment of biogas slurry in the reactor and subsequent cultivation of chlorella found that:taking the optimal conditions as a reference,the mold treatment biogas slurry experiment was carried out in an airlift reactor,and the pretreated biogas slurry was used for cultivation Microalgae.The decolorization rate of the biogas slurry by fungi is up to 62.15%.The removal rates of this strain on the biogas liquid ammonia nitrogen,TN,TP,COD in the reactor were99.3%,77.2%,89.6%and 88.6%,respectively.Chlorella grows in the biogas slurry treated with this strain for 20h.Chlorella sp.can grow in the biogas slurry pretreated by fungi,and it grows well.The maximum OD reaches 2.292,and the chlorophyll a concentration is 19.19mg/L.