The Maturity And Nitrogen Loss During Kitchen Waste And Sewage Sludge Composting

In the process of composting of kitchen waste and sludge,nitrogen loss is an important factor affecting the quality of composting products,different combination ratio and ventilation rate will cause unnecessary waste of nitrogen.In order to reduce the nitrogen loss,this paper takes kitchen waste and sludge compost as the research object,on the basis of compost maturity index and nitrogen loss situation,to selected the best ratio and ventilation.The result showed that:1)In the best ratio experiment,the addition ratio of different materials has signifycant influence on the duration of high temperature.T₃ treatment?kitchen waste,slud ge,straw addition ratio is 40%:45%:15%?the duration of high temperature period is significantly higher than other treatments.During the 15-day composting,excess kitchen adding ratio can inhibit the maturity index.Considering the total amount of kitchen waste and sludge,selection the kitchen waste:sludge:straw=40%:45%:15%of the material mix for composting.2)In the best ratio experiment,The nitrogen loss in different materials is very different.High kitchen waste or sludge addition will increase the NH₃ emissing and reduce the quality of compost.under the precondition of maturity,T₃ treatment can increase TN content by 25.39%.3)In the ventilation rate experiment,The effect of different ventilation rate on the accumulated temperature and high temperature period was significant.T₂treatment(0.36 L·kgDM^-1·min^-1)ventilation rate can meets the needs of microbial oxygen consumption and prolong the high temperature period and improve the accumulated temperature.The ventilation rate is 0.36 L·kgDM^-1·min^-1 can guarantee maturity index and use lower energy consumption.4)In the ventilation rate experiment,NH₃ emissions are mainly concentrated in the high temperature period,N₂O emission is mainly concentrated in the early stage of compost.At the end of the compost,T₂ treatment of NH₄⁺-N was significantly higher than the other two treatments,2.21 g·kg^-1DM.In the end,the content of TN is 33.27g·kg^-1DM,increased by 55.83%,obviously higher than the other two.