The Study On The Fermentation About The Mixed Material Of Animals' Waste And Rice Straw

Anaerobic fermentation technology has been widely applied in crop straws and livestock manure utilization. Temeprature is one of the important factors in anaerobic fermentation. Besides that, another factor influencing mixed fermentation is proportation. This research's aim is to demonstrate how to increase biogas yield from agricultural residues and provide a benchmark reference for the anaerobic digestion of mixed chicken manure and rice straw. Importantly, the findings will contribute to solving the problem of inadequate raw materials use in anaerobic digestion.Controllable-temperature fermentation equipment was used. Respectively, cow, chicken and pig manure and rice straw were combined in four proportions (0.5:1,1:1,2:1,3:1) to achieve 8% TS which was then treated at five temperatures (20°C,25°C,30°C,35°C,40°C). The optimal values for temperature and proportion of mixed raw materials that optimize biogas yield were calculated using multiple regression analysis. The main results obtained in this paper were listed as the followings.(1) In 20~40°C, Three kinds of raw materials were able to start-up anaerobic fermentation in a short time with normal producing gas. With the temperature increasing, the rate of producing firstly increased, then decreased in the process. The peak value appeared differently and obvious rule could not tell. After the peak, produce gas rate fell rapidly, then a few small peak emerged until fermentation finished.(2)In the three separate mixed raw materials'fermentation: cumuaitive production achieved maximum 12 234mL under 40℃and cow and rice straw proportion 2:1; cumuaitive production achieved maximum 12 234mL under 40℃and cow and rice straw proportion 2:1; cumuaitive production achieved maximum 12 234mL under 40℃and cow and rice straw proportion 2:1.(3)The temperatures and proportions as well as their interaction effect significantly affected the cumulative biogas production. The cumulative biogas yields were all increased in three groups with the temperature rise and decended at a certain temperature. When rice straw took more proportion in the whole TS, cumulative biogas yields showed the trends that increased at first, and then decreased.(4) All the data were analysed by math software, some best factors showed as below: when temperature was 39.8℃and rice straw took 3.17:1 in the whole cow manure and straw material, the predicted optimal gas output was 11469mL; when the temperature was 34.6℃and rice strew took up 1.93:1 in the chicken manure and strew material, the predicted optimal gas output would achieved 9513mL; when the temperature reached 39.8℃and rice strew took over 3.37:1 in the pig manure and rice strew material, the predicted optimal gas output was 6957mL.