Characteristics Of The CO₂Produced By Mold Activity And The Diffusion Law In The Rice During Storage

The mold is a main microorganism groups that can grow and harm in the ecologicalenvironment of the grain storage, the damage caused to grain is not reversible. Therefore, thescientific method to solve the safety of stored grain is able to remote real-time accuratemonitoring hazards parts and hazards conditions of stored grain moldy outside in the granary.At present, the use of CO₂gas detection method has been more mature to study therelationship between microbial activity and carbon dioxide gas, and can achieve positions ofmonitoring. So this experiment，mildew points of grain were buried in the different positionsof the rice bulk, and periodic testing of the CO₂concentration within the grain bulk. Researchthe relationship between the proliferation of CO₂and mildew sites, temperature and amountof mildew grasp; Master the diffusion laws of CO₂in the rice bulk, and analyze the parts ofthe grain mildew activities and harmful levels in the grain bulk, provide technical support forthe remote real-time monitoring insects and mold hazardous activities of the stored grain.Research the diffusion law of CO₂in different mildew position, whether the level ofmildew points in the grain bulk. The results show that, the concentration of CO₂increased thefastest and rate of change in mildew point,and mildew point closer the distance from surfacewithin the grain bulk, the greater the proportion of carbon dioxide gas spread to the outsideworld. In the horizontal direction, CO₂concentration showed a decreasing trend with theincrease of horizontal distance in all levels of horizontal. Especially in mildew point wherethe level, CO₂concentration is most significant changes, and in the more remote, thediffusion law of CO₂showed that lower> middle> upper>surface in grain bulk.Further studies the influence of different temperatures on the diffusion of CO₂gas obtained,the higher temperature of Grain bulk is more conducive to the diffusion of CO₂.Forexample, CO₂concentration in mildew of the30℃test group is0.01%lower than15℃testgroup, but the CO₂concentrations distance from the mildew at the same point is57%morethan15℃the test group. When the amount of mildew is not same, the ratio of CO₂concentration has no significant difference between the same test points and mildew point bythe variance analysis. This shows that the CO₂concentration of the grain bulk is not significant impact on the diffusion rate. That is, CO₂is spread as the equal proportion of themode in the grain bulk.The proliferation law of CO₂is the same in the different grain, only the changes of CO₂concentration is difference. In the same storage conditions and at the same time, the CO₂concentration by texting is the maximum in wheat grain bulk, followed by corn bulk and theminimum in rice bulk.Through research and analysis the diffusion of CO₂in various conditions, it can providereference for the moldy parts of the judgment, and improved the early prediction theory ofmold harmful activities. So the safety of China’s grain storage be guaranteed.