| At present,the garbage pollution is more and more serious in rural.In order to build the ecologically livable and beautiful village and to promote the utilization of organic waste in rural areas,this study carries out the research on aerobic composting of organic waste and human manure.The characteristics of aerobic compost is analyzed.Also,the mechanism of nitrogen loss and carbon conversion during composting and the principle of microbiology are investigated in order to provide a basis for optimizing composting process.The main results are as follows:?1?The average intensity of domestic garbage is 388.5 g/d per capita in Fushan village,and for winter and summer the intensity are 351.6 g/d per capita and 501.4 g/d per capita.The proportion of kitchen waste reach 47.7%56.3%in domestic garbage,the bulk density of domestic garbage is 277.6 kg/m3 and the water content is 44%.The low heat value of the wet base is 3466 kJ/kg.After the classification,the organic matter of the perishable waste is 74%and the C/N ratio shows 27:131:1.The organic components of the rural waste are suitable for composting.?2?After the aerobic composting of the organic waste and human manure,the rate of weight loss can reach 64%,the compost temperature can reach the requirements of the harmlessness,the moisture content of the pile is 50%60%.At the end of composting,the degradation rate of organic matter is 18%,the stock is alkaline,and the C/N is about17.The COD increases first and then decreases during the composting process.The trend of ammonium nitrogen increases first and then decreases.The content of nitrate nitrogen increases significantly during the mature period.The contents of total nitrogen,total phosphorus and total potassium in the mature compost are 21.4 mg/g,13.7 mg/g,18.7mg/g,respectively.The GI is close to 100%.?3?For the composting ventilation 0.15m3/min·m3,the pile is not completely decomposed.When the ventilation is 0.3m3/min·m3 and 0.5m3/min·m3,the compost are better decomposed,the total nitrogen loss are 45.3%and 58.5%.Considering the maturity,nutrient elements and power costs,0.3 m3/min·m3 is suitable for aerobic composting.Different ratios of mature compost are added,the temperature all meet the requirements.At the end,GI reach 88.2%,122.1%,and 108.5%.The loss of nitrogen are 38.3%,29.8%,26.2%,respectively.The mature compost has the advantage of adsorbing ammonia gas.The group with 10%mature compost shows the largest organic matter degradation rate and GI.Heating promotes the warming in winter.The temperature of the heating group can reach above 50°C.At the end of composting,the GI are 71%,97%,110%,and the HA/FA are 0.65,1.1,1.2,respectively.The initial heating improves the rate of reaction and the humification rate.The ammonia volatilization can be reduced for about 38.5%by mature compost adsorbing.The addition of superphosphate makes the contents of ammonium,nitrate and total nitrogen increase significantly.Adding 5%superphosphate shows higher GI at the end of composting.?4?The bacteria are the most abundant microorganisms during the composting process.The number of bacteria,fungi and actinomycetes increased first and then decreased,and the number of mesophilus decreased during the high temperature period.At the beginning of the composting,the activities of urease,sucrase and dehydrogenase are higher.With the composting process,the enzyme activity decreases.The activity of cellulase increases with the composting process.The microbial community diversity in the composting process decreases first and then increases.Proteobacteria,bacteroides,firmicutes,actinobacteria are the dominant phylum in the system.The dominant species in the composting system changed.The CCA analysis of bacterial and environmental factors show that the microbial communities have strong succession during the high temperature period,and the community structure are similar during the cooling period.The temperature,NH4+-N have significant effects on the succession of the bacteria community?P<0.05?. |
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