| Waste water treatment and recycling has become one of the ways to solve the problem of water shortage.With the rapid development of nuclear power technology,the discharge of radioactive waste water is also increasing rapidly.Because of nuclear power waste water has the characteristics of high salinity,radioactive and multi-pollutant species,nuclear power waste water is in the category of refractory waste water.According to the characteristics of high salinity,uranium and radioactivity in the radioactive wastewater containing uranium produced by Z company,the sewage treatment process of reverse osmosis membrane process and conventional deoiling technology is designed to make it reach the standard or reuse.Reverse osmosis technology is a new type of waste water treatment technology,its main features are efficient and safe,clean and environmentally friendly,simple process and multi-stage membrane treatment.In this paper,the treatment of uranium-containing radioactive waste water was studied by using ultrafiltration,first-order high-pressure reverse osmosis,secondary low-pressure reverse osmosis,ammonium salt precipitation and silica gel adsorption process.In the study,the recovery rate of fresh water,the rate of desalination and the components of fresh water are mainly investigated.The high salinity and uranium containing waste water produced by Z company as raw materials was studied.The effects of influent pH,influent water temperature,influent salt content,operation pressure and influent flow rate on the recovery and desalination rate of reverse osmosis were investigated.Experimental results showed that when pH was less than 8.5,desalination rate and the recovery rate of freshwater increase with the increase of pH,the desalination rate and the recovery rate of freshwater will decline sharply when pH>8.0;When the influent water temperature was higher than 30 ?,the desalting rate decreased obviously,and the recovery rate increased with the increase of inlet water temperature;The freshwater recovery and desalination rate decreased with the increase of the influent salt content.The freshwater recovery rate and desalination rate increased with the increase of operation pressure,but the change of desalination rate is slow.Considering the effect of various factors,orthogonal experiment was designed with the three factors:water pH,water temperature and operating pressure,results show that when water pH,temperature and operating pressure were 6.4,28?,82Kg,reverse osmosis desalination rate and water recycling rate reached a comprehensive optimal.Using the ultrafiltration system + first stage high pressure reverse osmosis +second stage low pressure reverse osmosis to separate and process the integratedwaste water of Z company.The results show that under normal operating conditions,the performance of the reverse osmosis system can meet the design requirements.When the salt content and uranium content in the integrated waste water seriously exceeded the design requirements,the fluoride content in the fresh water after the reverse osmosis process was 6.4 mg/L,and the drainage could not meet the standard.It should ensure that the water quality of raw water to meet the design requirements in order to ensure the separation of reverse osmosis system performance.The concentration of ammonium salt and uranium in concentrated water was mainly removed by treatment with ammonium salt precipitation and silica gel adsorption process.Ammonium salt precipitation mainly removes ammonium salt from waste water by chemical reaction.Silica gel adsorption mainly removes uranium from waste water.The results of operation of the equipment show that the amount of uranium in the tail water treated by the above process is less than 0.1mg/L,and the tail water pH range is 7?8,which meets the discharge standard. |
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