Study On Cow Manure Thermo-ophilic Fermentation Recycled Cow Bed Material In Large Temperature Difference Area

With the rapid development of China's economy and the improvement of people's living standard,animal food accounted for an increasing proportion of dietary structure and livestock breeding in the scale development.Livestock breeding industry has made a great contribution to the improvement of people's living standards,but a large number of livestock waste has brought serious pollution to the environment.Harmless,Resource and Energy utilization treatment of livestock manure is imperative.Cow manure thermophilic fermentation recycled cow bed material technology can realize in situ resource utilization and will not cause environment secondary pollution.It is a effective way that save the wider band cost for breeding enterprise and promote the coordinated development of breeding and environmental protection.However,in the area of relatively large temperature difference,cow manure thermophilic fermentation faces some problems such as slow heating-up,long period and difficult fermentation.In this study,the fermentation temperature,water content,pH value,microbial community structure and pathogenic bacteria were used as the standard of harmless fermentation to research the fermentation conditions in different seasons of the year.The results showed that the fermentation process in spring and summer could reach the heating-up stage and megathermal stage under field conditions.At the end,the water content was close to 50%;the fermentation period was 16 days and 12 days respectively;the megathermal stage was lasts 9 days and 10 days respectively.Autumn and winter did not reach the megathermal stage,indicating that low ambient temperature(-20-15oC)had a greater impact on the fermentation temperature.Study on regulation and control of cow manure thermophilic fermentation parameters in mild hypothermia: optimize the proportion of straw,different turning frequency and different microbial inoculum addition.The results showed that only the cow dung:straw =2:1(volume ratio),the fermentation reached a megathermal stage and lasted 7 days,the other proportion was not in the megathermal stage during the fermentation process.The turning frequency 4d/time as the optimum,which have the higher heating-up speed,longer period and lower water content at the end of fermentation;Adding microbial inoculum can obviously improve the fermentation efficiency and complete the thermophilic fermentation.When adding1.3 L/t,the reactor enters the megathermal stage time early and have long duration,the fermentation completes thoroughly.The optimal fermentation conditions of mild hypothermia were obtained,which could increase the temperature and shorten the fermentation period effectively.Study on the changes of microbial community in different periods of fermentation by PCR-DGGE.It was found that the microbial community was rich in the rapid fermentation in summer,especially in the heating-up stage and megathermal stage,the microbial diversity index was high,the dominant microflora was Clostridium,Bacillus and Flavobacterium.PCR fluorescent quantitative detection of pathogenic bacteria in the whole fermentation cycle.The results showed that Salmonella and Shigella existed in the initial stage and heating-up stage,no detectable at megathermal stage and the end of fermentation.Staphylococcus aureus was not detected.The Escherichia coli remained in the megathermal stage but was missed at the end of fermentation.Therefore,cow manure thermophilic fermentation recycled cow bed technology can meet the health and safety standards,fermented products can be used for cow bed material.