Application Study Based On RO Technique To Municipal Sewage Recycling In Power Plants

This paper introduces the problems of water shortage & water environment pollution which had severely hold beaked the society progress. Regenerative water is taken for solve this problem by more and more people. Sewage treatment and reuse as cooling-water can not only enlarge the scale of wastewater reused, but also supply a sufficient headwater. In the different kinds of water treatments, RO separation technique features it easy operation, equipment compact, safe working environment, and qualified quality water gotten at different reuse needs as well. So, it will be used wider and wider in the future.Taking a regenerative water treatment project in a power plant as an example, this paper analyzed the influent and effluent quality of RO membrane, recorded the function parameters in order to examine its treatment impression and stability. In the last, the paper probed into the benefit of this project.In this project, the pretreatment of RO membrane are GX bio-oxidation and two stage filtration. The operation results showed that the SDI of pretreatment effluent was beneath 4.0 and meet demand, so this technique is feasible to the pretreatment. In this paper, the site tracing monitoring of influent and effluent quality had been done during more than 6 months. All of the index systems, such as pH, electrical conductivity, NH₃-N, TN and TOC, conformed to the water quality demands of recalculating cooling water in power plant. The average content of NH₃-N and salts are 0.28 mg/L and 10.2 mg/L. By the study of RO membrane's desalinization ratio, recovery rate, pressure and other function parameters, got the results that the recovery rate decreased following with the time, opposed to the pressure. The paper assessed the stability and forecasted the operational life of the RO membrane.The project benefit evaluation indicates that it can save 3740000 t quantities of municipal sewage one year. The running expenditure is about 2.44 yuan/t, which is lower than tap water. It can reduce the discharge of TN, NH₃-N and COD_Cr about 145.9 t, 92.4 t and 300 t. In a word, this project can be applied by the other power plants widely.