Study On Wastewater Reuse And Sludge Disposal In Water Supply Department Of Electric Power Plant

This study is based on"the zero discharge project of water treatment department of Hechuan electric power industry."the wastewater from water treatment process has been studied. The wastewater consists of the sludge flushed out from the sedimentation tanks and the backwash water disposed from the filter beds. If this part of water is discharge into river where the raw water pumped from, it would pollute the raw water. Recently, wastewater and sludge from waterworks have been valued. Although wastewater treatment facilities in water plant have been constructed and studied, there is still lack of sufficient studies on wastewater treatment facilities in water department in power plant. To solve these problems, the practical and feasible waterworks'wastewater treatment process and system have been studied in details in this paper.Through one year's experience, the suspended sedimentation concentration and turbidity has been tested and their proportion relation has been confirmed. The proportion relation between SS and turbidity is 2:1. According to the statistical results of turbidity intervals, the mathematic model has been built to determine the value of raw turbidity. In this case, the raw turbidity can be used to calculate the quantity of sludge. The quantity of wastewater has been calculated based on the actual operation of water treatment process. And then, simulate test was adopted to do the sludge natural settling and coagulation sedimentation test, which can be used to determine the reflux ration of supernatant fluid in the concentration tank. The quality of supernatant fluid from concentration tank and the dewatered sludge has been tested to discuss whether the supernatant fluid as well as the sludge can be reused or not. Finally, through economic analysis, the input and output of whole project have been calculated.The research results show that, because of the feature of water supply department of power plant, the quantity of dewatered sludge is lesser than that in water treatment plant. The proportion between the quantity of dewatered sludge and in taking water is about 3%. The performance of sludge setting is good for sludge treatment. Supernatant fluid from concentration tank can be reused, which would not increase the burden of water treatment process or influent the effluent water quality. The heavy metal contains in dewatered sludge accord with national standard, so it can be used as turf soil. Although the input of waterworks wastewater treatment project is enormous, the cost of water purification and wastewater discharge can be saved. We can conclude that this project can bring about huge environmental, social benefit as well as economic benefit.