| Objective: Research on the composting process providing a theoretical basis for high-moisture and high organic content of biological waste pretreatment, biological pretreatmentMethods: 1) The process of high temperature aerobic composting of MSW was simulated in this experiment. Some changing indexes of character related to pretreatment were measured. 2) Based on the analysis of experimental data and reaction dynamics, the mass and energy conservation were developed. 3) Developed a C language program to simulate the variation of organic content, the moisture content and temperature during the pretreatment process of MSW. 4) The feasibility of compost applied to pretreatment of MSW was probed from the point of engineering application. Three group projects of MSW treatment with or without composting pretreatment process were compared by means of cost-benefit analytical method. The techno-economy effects of each group were evaluated quantitatively and qualitatively.Results: After biological pretreatment, the loss rate of garbage's weight is about 32~41%. The rate of reduced volume is about 35~45% and volatile solids in the degradation is about 56~71% and increased density is about 8~10%.The concentration of ammonia nitrogen leaching solution dropped from 50 mg/l to 30mg/l on average. The equation of moisture variety, equation of heat balance, model of microbial growth and a dynamic model of organic matter degradation model fit well with the experimental data.Conclusions: Bio-pretreatment can obviously reduce weight and water content of original MSW, and reduce the concentration of NH3-N in the lixivium and increase the caloric value of MSW. Composting pretreatment combined with incineration, sanitary or comprehensive treatment was feasible in engineering according to the component characteristics of MSW in our country. Its economic indexes were better than those of traditional MSW treatment project without composting pre-treatment.
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