BigPatents India

At present the sewage sludge that is generated is being dried in sewage treatment plant in long beds by sun drying. The drying beds occupy large area, are subject to vagaries of climate, takes a long time to dry and even then contains fairly good amount of moisture and is stored in open grounds before selling because of its moisture content. The proposed system of drying of the sewage sludge in the sewage treatment plant envisages passing the sludge over a mesh type conveyer belt and dehydrating the sludge (removal of the water from the sludge) by a suction mechanism below the belt. Most of the water will be removed from the sludge by suction by the time the sludge reaches the middle of the conveyer belt and the remaining moisture will further be reduced by the slightly warm air that passes over the belt from the top. By the time the sludge reaches the end of the conveyer belt, it will be in a powdery/ paper form and can be scrapped easily. The dried sludge when it reaches the end of the belt is scrapped automatically, dropped into the bags via a hopper and is automatically bagged (including stitching). This can be stored and sold to the farmers at any point of time. This system is not subject to vagaries of nature like rain, can be operated continuously all through the 24 -hour of the day, requires only little space as it is like a factory type one compared to present method of sun drying, can utilize the energy source (methane gas) available within the sewage treatment plant, requires little manpower to operate and maintain as it is mechanized, can be tailored to suit the amount of sludge generated over different periods of the day and the year, also cost effective, in addition to other direct and indirect benefits like assuring the farmer of quality produce, availability throughout the year, feasibility of selling it through retail outlets etc. This mechanism \vill reduce the pollution hazards and also will be farmer friendly besides being highly cost effective.