抄録
Composting involves the biological decomposition and stabilization of organic materials under conditions that allow the development of thermophilic temperatures as a result of biologically produced heat, and should yield a final product sufficiently stable for storage and application to land without adverse environmental effects.Aerobic composting, the decomposition of organic materials in the presence of oxygen, releases significantly high energy per weight of the organics decomposed.Thus, aerobic composting is suitable for production of a thermophilic temperature under which the decomposition rate of organics is high. Further, the process results in considerable drying of the final material;this is effective for reduction of subsequent handling costs, increases the attractiveness of compost for reuse, and pathogens and parasites that may be included in the original composting material are destroyed.The present article summarizes the special conditions of moisture and aeration required for effective aerobic composting. Further, the effects of the turning of the composting material on the rate of organic matter decomposition during the aerobic composting have been overviewed.A numerical model is then introduced in order to calculate the rate and the degree of organic matter decomposition, the temperature, and the moisture content under various aerating operations.The model was used to investigate the optimum conditions to obtain sufficiently dry compost.Calculations based on this model suggest that water can be eliminated most effectively when aeration is controlled such that the reactor is kept at its optimum reaction temperature;i.e., 60°C.
