Determination of Optimal Pile Dimensions during Thermophillic Windrow Composting of Municipal Solid Waste (Msw) in Sri Lanka

Abstract

 Abstract—This study was done to determine the optimal pile dimensions for thermophilic composting and to determine turning frequency to maintain thermophillic conditions. The results showed that minimizing of surface area to volume ratio (SA/V) of compost piles is important to increase the efficiency of the process. All the piles used for the study recorded thermophilic temperatures irrespective of having SA/V ratio less than 1 as stated in the literature. The results further indicated that attention should be given on deciding the temperature measuring points of the compost pile and revealed that due to the heterogeneity of municipal waste, changes of volatile solids and moisture content are not suitable indicators of decomposition rates of waste. The best measure of decomposition of organic matter in field scale composting of MSW is the temperature profile of a pile and the heat generated in the pile. The temperature profile of the composting mass is least affected by heterogeneity of the waste and least prone to field scale sampling errors by being the easiest parameter to measure in a field site. Therefore, good attention should be given on type of waste, maximum height and turning frequency of the pile when designing a windrow composting plants.