The Study On Composting Of Msw Biological Pretreatment And Product

The composting of solid waste was not only the way out of solving the problem and recycling and achieving the objective of harmlessness of municipal solid waste, but also could be used as a biological pretreatment technology for quantitative reduction of the garbage. It is a research hot spot at present in the field of waste treatment.Objective: Composting experiment was carried out at Huangjiawan landfill site of Yichang. Volume reduction and decrement in pre-treatment procedure, shorten the Period of decomposition were deemed to the evaluation index. Optimizing process parameters. Providing evidence for the composting of municipal solid waste.Method: conducting experiments on Landfill site, sampling to monitor changes of the parameters and transformation process of moisture, organic matter, nitrogen and phosphorus in process. To monitor the degree of garbage decomposition (plant toxicity and oxygen consumption rate). Comprehensive analysis the effects of pile-turning and aeration on the Period of composting decomposition. Furthermore, Analyzing the Results of our experiment.Contents: Firstly, studying on the Process of the primary fermentation (biological pretreatment); Secondly, studying on the Process of the secondary fermentation (composting with product yielded by pretreatment), then, optimizing fermentation process parameters, and Finally, investigating the decomposition indexes and Parameters on composting.Result: Firstly, the percentage of weight loss reached from 10% to 30%,the decrease of waste volume were above 20%,and the degradation rate of volatile organic compounds were from 16% to 51% after biological pretreatment which suggested the moisture content of waste was significantly reduced and its calorific value was improved by biological pretreatment. It is favorable for subsequent treatment. Secondly, The optimized conditions for biological pretreatment were as follows: Ventilation time for 8h, half an hour each time, 2 tons water were added into waste to Guarantee the appropriate moisture content. The pretreatment time is five days. The optimized conditions for secondary fermentation through monitoring pile-turning and aeration were as follows: Ventilation for 8 min per half an hour, starting fan for 8h per day, Stopping ventilation when the temperature was below 35℃,pile-turning once for double days, and Stopping pile-turning when the temperature was below 35℃. Finally, the seed germination index, ammonia nitrogen and nitrate-N ratio and oxygen consumption rates were monitored through on-site testing, which demonstrated above indexes were feasible to evaluate decomposition degree, and providing a experimental evidence.