Study On Aeration Pattern Of Intensified MSW Composting With Leachate Recirculated Inoculation

With the development of modern aerobic composting, in China and overseas, many effective processes have been developed, which have different aeration patterns. Although these patterns may have some common parts, there are lots of differences among them because most of processes aim at special municipal solid wastes (MSW). Therefore, "Intensified MSW Composting with Leachate Recirculated Inoculation", as a new process to deal with MSW of towns with high water content, has its own aeration pattern, which can not copy other patterns totally. It is necessary to develop a suitable aeration pattern. This paper, basing on the study of other aeration patterns, has experimented four aeration patterns and takes the best as the aeration pattern of the process through evaluating, choosing and optimizing. Using downtown MSW in Chongqing as material, the paper has study four experimental aeration patterns.The study shows that differences of compost effect among four aeration patterns are much obvious. But each pattern has its own special advantage according to the various parts of compost effect, such as innocuity, reduce, microbe active and environment, maturity and energy consumption of compost etc. To select a suitable pattern, the paper has established an evaluation system with the application of fuzzy mathematics, and evaluated four aeration patterns from five parts, through taking nine parameters. The evaluation shows that the subjection rate of "better"grade of the fourth is 0.270, while the subjection rate of the second, third and first pattern are 0.209, 0.143 and 0.100; and the subjection rate of "good"grade of the fourth is 0.525, while the subjection rate of the second, third and first pattern are 0.497, 0.487 and 0.408. Therefore, the fourth aeration pattern is the most suitable one of "Intensified MSW Composting with Leachate Recirculated Inoculation"process. The fourth pattern is continuous bottom flow and low flux. To optimize the pattern, the paper has taken more study of modes of aeration, oxygen content, aeration volume and control modes of aeration. The study shows that the aeration pattern with continuous bottom flow and low flux can decrease the temperature grads and oxygen content grads with 44.89% and 24.13 %( comparing with the max.); and the oxygen content in the compost which is above 5% can meet the demand of aerobic ferment. The air flux which is between 0.05 and 0.1 m3/ (min·m3) also reach good compost effect, that is to say, its energy consumption is much less. Comparing to other control modes of intermittent aeration, the aeration system with continuous bottom flow and low flux not only have a better compost effect but also bring a simple operation and management. Through evaluating, choosing and optimizing four aeration patterns, the paper concludes that the aeration pattern with continuous bottom flow and low flux is the best suitable one.