The Desalination Study Of Power Plant Waste Water

Desalination technology is to reduce or remove salts in raw water through physical or chemical methods,which is used for water purification.Coal-fired power plants produce large amounts of waste water in the process of production.In order to can meet the wastewater discharge or reuse,Requires effective desalination technology for processing.This paper compares several desalination methods,at the same time,considering the power plant water quality requirement of the wastewater and water reuse,choose ultrafiltration as pretreatment,reverse osmosis as post-processing methods,to do the power plant waste water desalination processing experiments,and get the following conclusion.In the ultrafiltration experiments,through the water yield of ultrafiltration equipment,water pressure,recovery,circulation to adjust and optimize the parameters,such as,ultimately determine the operation parameters as follows:Feed water pressure is 75 kpa,return water flow rate was7.0 L/min,strong water flow rate was 2.7 L/min,Reverse osmosis water flowr rate was 45 L/min.Under the above conditions,the backwashing cycle of ultrafiltration equipment can be more than a month,And ultrafiltration water turbidity,generally under 0.1 NTU,SDI15 mostly in 0.5 the following,and far less than the reverse osmosis water index(SDI15<3).Accordingly,ultrafiltration system will provide good quality water for reverse osmosis system.In reverse osmosis experiment,using the four Hydecanme membrane element,The recovery rate of reverse osmosis at around 47%,compared with membrane element design manual,the data is very ideal.During the period of reverse osmosis equipment operation,although the electrical conductivity of the feed water fluctuation is bigger,but the produced water conductivity is less than 30 mu s/cm,desalination rate is over 98%,the removal rate of hardness basically reached 100%.Through the cost accounting,the use of ultrafiltration + reverse osmosis method power plant wastewater treatment,water cost about 0.79 yuan per ton.Therefore,ultrafiltration+reverse osmosis composite application in coal-fired power plant of wastewater treatment is very feasible,not only can reduce or eliminate waste water discharge,but also has certain economic significance.The results of this paper for the discharging standard and the recycling of waste water in thermal power plants has a certain reference value.