Research On The Preparation And Application Of Rapid Composting Compound Bacteria For Slaughtered Waste Under Low Temperature And Hypoxia Conditions

In view of the problem that the long time and low efficiency of composting of slaughtered wastes due to the natural conditions of low temperature and hypoxia in the Qinghai-Tibet Plateau,this paper studied the microbial community changes during composting under special conditions and screened out the four microbes suitable for low-temperature and anoxic composting such as Bacillus smithii,Bacillus coagulans,Aneurinibacillus thermoaerophilu and Geobacillus caldoxylosilyticus.The effects of four microbes on the physicochemical parameters of compost were studied by single factor experiment,and the effects of multiple factors on the physicochemical parameters of compost were studied by orthogonal experiment.It provided some references for the utilization of slaughtered wastes.The main conclusions were as follows:(1)Under the condition of natural compost,the differences between rotten and raw fertilizer were significant,which was mainly reflected in the microbial content of Firmicutes,Proteobacteria,Actinobacteria,Bacteroidetes.The number of Firmicutes and Actinobacitera increased,and the relative contents in rotten fertilizers were 0.503 and 0.078,respectively.Using high-temperature rapid composting mode,the diversity of bacterial community decreased rapidly after high-temperature drying,and then did not change significantly during composting.In the composting process,the differences of community structure in different periods were significant(p<0.05),the differences of Firmicutes,Bacilli and Bacillales were extremely significant(p<0.01)in each period,indicating that they played an important role in composting process and could be used for further composting study and Biomarker for composting process.(2)Through the single-factor simulation experiment,all four kinds of microbes could promote the maturity of compost.The moisture content was 23.74%at 70 ? and 35.89%at 60 ?.which were the lowest and the highest in the control group.The addition of the fungicide showed a decrease at 60 ? and a increase at 65 ? and 70 ?in the moisture content.The lowest pH at 65 ? in the concentration of 10%Geobacillus caldoxylosilyticus was 6.41,and the highest at 65 ?in the concentration of 10%Aneurinibacillus thermoaerophilu was 8.16.The lowest EC at 70 ? in the control group was 3.32 mS/cm,and the highest at 65 ? in the concentration of 20%Bacillus smithii was 5.11 mS/cm.The lowest C/N at 65 ? in the concentration of 10%Bacillus coagulans was 13.07,and the highest at 60 ? in the concentration of 10%Aneurinibacillus thermoaerophilu was 17.46.The lowest germination index at 70 ? in the control group was 0.55,and the highest at 70 ? in the concentration of 20%Bacillus smithii was 1.84.(3)Under the compound condition,the composting results were significantly affected by temperature and four microbes(P<0.05).Among them,the moisture content was significantly affected by temperature(r=-0.9314**),and the moisture content decreased with increasing temperature;pH was significantly affected by temperature(r=-0.6822**);EC was significantly affected by temperature(r=0.6070**)and Geobacillus caldoxylosilyticus(r=0.7265**).The total carbon content was significantly affected by Geobacillus caldoxylosilyticus(r=0.5070*),Bacillus smithii(r=-0.5199*),Bacillus coagulans(r=0.5678*);the total nitrogen content was significantly affected by temperature(r=0.6682**);C/N was significantly affected by temperature(r=-0.6206**).The germination index was significantly affected by Bacillus smithii(r=0.5886*).Bacillus coagulans and Aneurinibacillus thermoaerophilu had significant interactions on pH(r=0.6176**),EC(r=-0.6528**)and germination index(r=-0.5044*).