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Study on the Three-stage Inoculant and Lignocellulose Gegradation in Dairy Manure Composting

Author: LiuZhang
Tutor: NingPing
School: Kunming University of Science and Technology
Course: Environmental Engineering
Keywords: composting microbial inoculant dairy manure Lignocellulose degradation
CLC: S141.4
Type: Master's thesis
Year: 2011
Downloads: 23
Quote: 0
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Abstract

The dairy manure increased year by year with the large-scale development of dairy cattle breeding in Dali, which has been serious polluted the surrounding environment due to lack of cost-effective technologies and inappropriate disposal.. It’s easy to reduce fertilizer efficiency of the N, P and other nutrients and leaded to the eutrophication of Erhai Lake while using the traditional method of retting pits. Microbial inoculants can achieve the cow manure reduction, safe and resource utilization. However, the research of making microbial inoculants existed many questions, such as the competition of indigenous microorganisms, and the effectively degradation of lignocellulose. To solve these questions, a method of three-stage microbial inoculants was proposed, that is to isolate the high-temperature bacteria, lignin degradation and cellulose degradation microorganisms from cow dung, to add them in early period of compost, later period of high-temperature, and later period of compost respectively and then to achieve high temperature maintenance and effective degradation of lignin and cellulose. In this work, the feasibility and effectiveness of this strategy have been studied.Cultivating the dairy manure through simulated condition of composting, then obtained a thermophile and two high-temperature Actinomycetes after separation, purification and screening. We also obtained two white rot fungi based on the extracellular enzymes and got a rhizopus, an Aspergillus based on the cellulose degradation experiments. Those microorganisms were cultured and get spores and mycelia. In this work, white rot fungi inoculated with mycelia and the other microorganisms inoculated with spores.The experiments used dairy manure and straw as materials, inoculated thermophile, lignin degradation fungi and cellulolytic fungi in the initial period of composting, later period of high-temperature and later period of compost respectively. The results showed that when the compost temperature was beyond 55℃for 7 days, the degradation rate of lignin was 35.21%, degradation rate of cellulose was 43.19%, C/N decreased from 29 to 16.488 after 45 days. In the control experiment, when the compost temperature was beyond 55℃for 4 days, the degradation rate of lignin and cellulose were only 15.27% and 25.21% respectively and C/N decreased from 28 to 21.745. Microorganisms isolated from cattle manure have ability to compete with indigenous microorganisms effectively, increase the composting temperature and degrade the lignocellulose efficiently.

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