(I) Static windrow process
Static windrow composting is the simplest and oldest composting method. It piles the materials in windrows in the open air or under a frame and ferments them under aerobic conditions. The cross-sectional shapes of the windrows vary, such as trapezoidal, triangular, etc. The ventilation and oxygen supply of windrow composting is achieved by turning the pile regularly, and the fermentation cycle is usually 30-90 days.
The advantages of this
organic fertilizer composting process are simple equipment and low cost; easy to dry, high quality and good stability of compost products; the disadvantages are large land occupation, long composting cycle, large amount of turning machinery and manpower, frequent inspection, easy to have odor, and greatly affected by climate.
(II) Trough turning composting process
On the basis of the static windrow composting system, forced turning and ventilation devices are added to become a forced ventilation composting system, which can more effectively reduce heat loss and increase the duration of high temperature. It is different from the windrow system in that during the composting process, a blower is used to force oxygen to the pile, and the pile is turned intermittently by mechanical equipment. This organic fertilizer composting process is designed with some ventilation pipes at the bottom of the pile, which are connected to the blower.
In addition, the pile should be made on a solid and impermeable ground to prevent soil contamination by seepage. The advantages of this system are that it occupies a smaller area than the static windrow fermentation system; the cost is relatively low, and the system has temperature control and ventilation control, etc.; the composting cycle is relatively short, generally 14-21 days; the product has good stability and can kill pathogens in time; the disadvantage is that the fermentation process is easily affected by environmental conditions.
(III) Tank fermentation process
The tank fermentation process technology originated in the field of livestock and poultry manure treatment in Japan. There are blades inside the equipment that can transport air and stir. Under aerobic conditions, aerobic bacteria can decompose organic waste and evaporate the water in the waste, turning the organic waste into high-quality organic fertilizer. The moisture content of organic fertilizer after fermentation can reach 30%-45%. The temperature during fermentation can even reach 50℃-70℃, which can ensure the killing of various pathogens and weed seeds, and produce safe organic fertilizer.
The advantages of this
organic fertilizer composting process are short system construction cycle, fast fermentation, and the shortest composting cycle can be 1-3 days; less odor, high degree of automation, convenient operation, small footprint, and can save plant construction investment.
