| With the development of the times,the contemporary agricultural structure began to change gradually.and the livestock and poultry breeding industry has developed rapidly.However,the environmental pollution caused by a large number of feces discharged from large-scale and densely distributed livestock farms has aroused widespread concern of the society.At present,aerobic composting technology has become a widely used cattle manure treatment method at home and abroad because of its low energy consumption and green treatment process.However,due to the problems of low ambient temperature,high moisture content of manure itself,low microbial activity or single function in composting process.the method has the disadvantages of too long maturity cycle of cattle manure composting.In order to solve this problem,the purpose of this study is to optimize the composting fermentation process through functional microorganism screening,and to establish a rapid composting technology of cattle manure resource utilizationIn the treatment of solid compost fermentation technology of livestock and poultry manure,a variety of microorganisms with different solid fermentation functions play an important role.Therefore,according to the requirements of composting on high temperature tolerance,rapid growth and reproduction,and the ability to decompose pollutants,microorganisms with certain functions were screened out through different media.In this study,cattle manure from Jimo farm and Hebei farm were used as samples to screen functional microorganisms.Six kinds of commonly used culture media were selected,which were LB medium,Gauze's synthetic medium No.1,Potato dextrose agar medium,Silicate bacteria medium,Ashby's medium and Photosynthetic bacteria medium.They were used to screen the functional microorganisms needed in the fermentation technology of cattle manure solid compost.LB medium is mainly used to screen bacteria,Gauze's synthesis No.1 medium is mainly used to screen actinomycetes,PDA medium is mainly used to screen fungi,Silicate bacteria medium is mainly used to screen bacteria with the ability of dissolving phosphorus and potassium,Ashby's medium is mainly used to screen nitrogen fixing bacteria,Photosynthetic bacteria medium is mainly used to screen photosynthetic bacteria with light as energy source and sulfide as hydrogen donor for photosynthesis.17 strains of bacteria were isolated and purified by 6 kinds of medium.17 strains were identified by sequencing and analysis of molecular technology:Bacillus subtilis;Bacillus licheniformis;Sphingomonas organisms;Micromonospora citrea;Bacillus anthracis;cronobacter sakazakii;Bacillus cereus;Pseudomonas sp.;Enterobacter cloacae;Ralstonia pickettii;Phyllobacterium myrsinacearum;Bacillus toyonensis;Cellulomonas hominis;Azotobacter salinestris;Cellulosimicrobium cellulans;Acremonium sp.,Alternaria tenuissima.The characteristics and functions of each strain were predicted by consulting the literature.According to the function prediction of the selected strains,the common pathogenic bacteria in the soil,such as Cronobacter sakazakii,Enterobacter cloacae,which are not clear in the composting process and have diseases,are excluded from the selected strains.According to the characteristics of composting temperature rising stage,select strains that can withstand high temperature,have the ability of material transformation and cellulose decomposition,such as Bacillus subtilis:Bacillus licheniformis;Bacillus cereus to optimize composting temperature rising process.Three kinds of microorganisms were prepared in the proportion of 1:1:1 to add into cow manure for temperature rise observation,and the commercial compost bacteria were used as the control.Through the comparative analysis of compost temperature rising results,it is found that the self-made mixed bacteria can play a better role in the treatment of Jimo cattle manure and Hebei cattle manure.In this study,the best composting effect can be obtained when the inoculated amount of self-made mixed bacteria is 3%(v/v)and the initial C/N of solid fermentation is 25.The temperature rising rate of Jimo cattle manure and Hebei cattle manure was about 3.57? h-1,and the time of keeping high temperature was about 14 h,45 h,respectively.The maximum temperature is 62? and 65? respectively.The temperature rising rate was increased by 1.72? h-1,and the high temperature maintaining time was increased by 4 h.And the maximum temperature increased by about 7?.At the same time,this study also discussed the selection of five initial carbon sources in composting,the priority of which was wheat bran>corn flour>glucose>wheat straw>corn straw.Compared with other substances,wheat bran has more environmental protection and economic value.It can not only meet the conditions of environmental treatment,but also realize the resource utilization of waste.Solid fermentation of cattle manure is a very complex biochemical reaction system.and its internal parameters are both independent and interrelated.In this study.the changes of some components(such as pH,TN.TP.etc.)with fermentation time in the process of solid fermentation of cattle manure were detected.Through this study,it was found that in the composting process with Jimo cow manure as substrate for 28 days,the water content showed an overall downward trend,from 55%of the initial stage of solid composting fermentation to 30%.The pH trend first rose in this solid fermentation process,and then slightly declined,reaching 9.51 when the pH was the highest.TN first declined and then stabilized in this solid fermentation process,and the content before and after the process decreased by about 5.1 mg g-1 in this process.The content of TP also decreased first and then stabilized,and the content decreased about 0.15 mg g-1 before and after this process.In this solid fermentation process,the trend of organic matter decreased all the time,and the content decreased about 40.3 mg g-1 before and after this process.Water content,organic matter,TN and TP content have all reached the production standard of NY 525-2012?Organic Fertilizer?after treatment.The results showed that pH and water content were the main environmental factors affecting the composting process.In the early stage of composting,when the composting treatment is about 10 days,part of water can be added to the compost to ensure the overall water content is more than 50%,and maintain the activity of solid compost fermentation function bacteria in the compost.In the composting process of this system,the pH is slightly higher about 9.2.When the pH is too high,it is not conducive to the normal metabolism of microorganisms,and it is easy to cause the loss of N elements.During the composting process,a proper amount of FeSO4·7H2O and other acidic substances can be added in real time to adjust the pH of composting to make the life activity of microorganisms more vigorous in the composting process.And it can improve the composting rate and achieve the purpose of rapid treatment of cow manure and nitrogen conservation,too. |
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