The effects of aeration rate on generated compost quality, using aerated static pile method

To determine the most appropriate composting process in an active municipal solid waste system, an experiment was carried out using a nested design method with three aeration rates. During each aeration rate, parameters such as temperature, pH, EC, carbon-to-nitrogen ratio, NO3–N, nitrogen, potassium and phosphorous were measured and the efficiency of different composting processes was evaluated. The result of this study showed that the lower and medium aeration rates had a significant impact on nitrogen, carbon-to-nitrogen ratio and temperature profile, while higher aeration rates led to higher EC values. Furthermore, the thermophilic phase lasted 13, 9 and 4 weeks for the aeration rates of 0.4, 0.6 and 0.9 L min−1 kg−1, respectively. Accordingly, it was concluded that starting at a rate of 0.6 L min−1 kg−1 during first 2 months (about 9 weeks) of the process and continuing at a rate of 0.4 L min−1 kg−1until the end of composting process would result in lower energy consumption.