| Today, with the rapid growth of the population and the quick development of the economy,the natural resources in the world are being consumed swiftly and the technology of reuse of waste is being attached more importance by many countries.The lack of the natural resources in China is so serious that it has made the research of resources reuse even more important than ever. The sludge of urban sewage disposal plant, living garbage and coke breeze are the waste produced in the process of urbanization, and the treatment and disposal of those wastes are unavoidable problems eventually. Because there are a lot of the sludge of urban sewage disposal plant and living garbage, which could not find safety way to go,and that is very easy to cause the secondary pollution. At present, some of national sewage and garbage plant cannot bring into play owing to their lower technology, higher running cost and more difficult product distribution. So, there is important significance to carry through the research of resources reuse producing organic combined fertilizer by use of the sludge of urban sewage disposal plant, living garbage and coke breeze. Based on systematic summery to the research actuality in this fields, the thesis make researches about the following questions.Based on the fact that there is abundant nourish component and organic matter in the sludge of urban sewage disposal plant for crops to grow and there is lower content of heavy metals, which can meet the national agricultural standards, the aurthor put forward the viewpoint using the sludge of urban sewage disposal plant to produce organic combined fertilizer.The thesis also makes research to characteristic of microorganisms in the process of composting, concludes that the most important factor is organic matter and temperature and the next factor is pH. Through the research of the degradable relationship between microorganisms and organic matter in compost, the author think it more favorable in temperature the condition of middle temperature to degrade organic matter, and divide compost to middle transition pHase, middle temperaturepHase and middle-low temperature transiton pHase.For the sake of innouity aim,the research uses compost production to develop organic cumomed fertilizer. According to the characteristic of organic combined fertilizer and integrating compost product component, soil property and nourish condition of crops, the author defines the best ratio of organic combined fertilizer and technics flow of producing organic combined fertilizer. The author also develops special organic fertilizer in rice, and does fiels experiments using oranic combined fertilizer. The results of the experiments show that those fertilizers have fairly effect on increasing production to rice.Herb residues or wood chips could be used as bulking agents through forced aerated static static pile model of municipal sewage sludge, but the former had better effects. The temperature of above 55C in a pile could be observed on the third day after composting and kept 8 to 11 days. Based on the consequent experiments including the effects of bulking agents amended into the sludge and the various ventilation rate on composting, the optimal technological parameters were proposed:The volume ratio between sludge and agents were 1:1 or 1:3, and the ventilation rate was 0.35m3/t.min with frequency of 30min per 3 hours. The cress seed germination index (GI), used as indicators of pHytotoxixity and maturation of compost, exhibited that the sludge compost was stabilized and mature near 40th day of composting, when 80% of GI was obtained.Compsting is one of the most acceptable methods for treating orgtanic solid waste, but maturity assessment is still a main problem of this pratice.In this study, pHysical, chemical and biological indexes were used to find some easy methods to assess the maturity of composting.Chemcal indexes depend on the raw materials, pHysical indexes need a long time to determine. Nutrients were alsodetermined to search the transformation principl... |
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