Temperature is one of the most important factors that affect the activity of microorganism and composting process. It restricts the activity of microorganism and the decomposition speed of organic matter, and directly affects the fermentation degree and composting time of composting. In the first 3-5 days of composting, the main purpose of gas supply is to meet the oxygen supply, so that the biochemical reaction can be carried out smoothly to achieve the purpose of high temperature. When the compost temperature rises to the peak value, the air supply is mainly controlled by the temperature.
According to the harmless standard in the organic fertilizer production line
, it is an important condition to keep the temperature of the compost at 55 ° C for three days, or above 50 ° C for five to seven days, to kill the pathogenic bacteria contained in the compost, to ensure that the hygienic index of the compost is qualified and the compost is mature. The temperature of the compost is usually controlled by adjusting the ventilation or compost turning machine. The growth of different kinds of microorganisms has different requirements on the temperature.
Generally speaking, the most suitable temperature for thermophilic bacteria is 30° C-40 ° C, and the most suitable temperature for thermophilic bacteria fermentation is 451° C-60 ° C. In the early stage of composting, the compost layer is basically in medium temperature, thermophilic bacteria are more active and propagate in large quantities. In the process of using organics, some of them are converted into heat, and the temperature of the stack layer keeps rising. After 1-2 days, it can reach 50 ° C-60 ° C.
At this temperature, the growth of thermophilic bacteria is inhibited and a large number of them die, while the reproduction of thermophilic bacteria enters into the excited state. The heat source of temperature rise in composting process comes from the heat released from the decomposition and metabolism of organic matter by microorganisms. In the process of composting, too high or too low temperature will have adverse effects on composting. The temperature is low, the reaction rate is slow, and it can not meet the requirements of thermal inactivation and harmless.
In addition to rapid reaction rate, high temperature can kill eggs, pathogens, parasites, etc. to achieve harmless requirements, so high temperature composting is generally used. However, when the temperature is too high (> 70 ° C), beneficial bacteria such as actinomycetes will be killed, which is not conducive to the composting process. The reactor temperature shall be controlled at 45 ° c-65 ° C, and the most suitable temperature is 55 ° C-60 ° C.