Investigation of drying secondary agricultural products with sewage sludge of Sakarya

In this study; instead disposal of sewage sludge from treatment plant, which one of the energy and environmental problems, has been investigated for use as alternative fuels. Sewage sludges were obtained from the wastewater treatment plant of Sakarya Metropoltan Municipality. In order to increase the energy value of sewage sludge, the homogeneous mixture is prepared by adding different ratios of nut shell that is the secondary agricultural products. Then open sun, microwave and oven drying were applied for reducing the high moisture content in the structure of the prepared sample. Drying efficiency and the usability for alternative energy sources have been investigated. While Maximum energy was consumed in oven during drying,in the microwave the least energy consumption was seen and also the highest specific energy consumption values were in oven drying. Sewage sludge drying time in the open space is very long compared to other methods. However, it is the one in the open field with the least cost. It has been seen that the minimum and the maximum heat of the sewage sludge mixtures after the drying process are 3,4 and 4,9 mcal/kg respectively. As the minimum and maximum heat of the brown coal which is used in power plants common in our country varies between1-4,2 mcal/kg, the mixtures that derive from sewage sludge can be used as an alternative or supplementary fuel.