Effects of ventilation on aerobic composting of organic wastes

Aerobic static co-composting of agriculture organic wastes(corn straw) and organic fraction of municipal solid wastes under different ventilation rates of 0.05,0.15 and 0.2 m³·min^-1·m^-3 was studied in lab-scale for obtaining the best ventilation rate. The changes of physical and chemical properties(such as temperature, pH value, water content), nutritional factors (such as available N, available P and ratio of carbon to nitrogen), and the degree of humification (humification index and the E₄/E₆ value of Humic Acid) in composting material were measured to examine the feasibility of co-composting of agriculture organic wastes and organic fraction of municipal solid wastes. Results show that organic fractions of municipal solid wastes and corn straw can be used to co-composting under different ventilation rates. When the dry basis ratio of organic wastes of municipal solid wastes and corn straw was 5:1, initial water content was 55%, and the initial ratio of carbon to nitrogen was 34:1. It could not only enhance the temperature of piles and keep the high temperature for longer time, but also decrease the loss of nitrogen and accelerate the degradation of organic substance and the degree of humification at the ventilation of 0.15m³·min^-1·m^-3. It was beneficial to the accumulation of available N and available P, with the ventilation of 0.15m³·min^-1·m^-3 better than others.