Enhancement of carbon and nitrogen transformations during composting of municipal solid waste

Appropriate management of municipal solid waste (MSW) is viewed as an integrated system encompassing waste minimization, recycling, and resource recovery. This has increased the interest in the composting process, in which the biodegradable portion of MSW is biologically converted into a valuable product that can be utilized as a soil conditioner or fertilizer. Effective operation of the composting process can be achieved by determining the optimal conditions for the controlling parameters in order to enhance the biological reactions during composting. Information on biodegradation rates are also essential for process design. Therefore, this study was conducted in order to examine the factors affecting process performance and transformation of essential elements of MSW such as carbon and nitrogen. A pilot study of in-vessel aerobic composting of MSW was carried out and the operating parameters, which affect biodegradation of carbonaceous and nitrogenous matter were studied using a specially designed rotating drum and a carbon-rich MSW. The effects of temperature, moisture. content, and air flow rate were examined. The performance of the composting process was evaluated by measuring the carbon and nitrogen content during experiments, each of which lasted for 30 days. The study showed that enhanced transformations of carbon and nitrogen occur at 55degreesC for temperature, 60% for moisture content, and 10 L/kgh for air flow rate using the food-rich MSW generated in the Gulf countries.