Emulsion Liquid Membrane Technology Research Recycling Waste Containing Uranium

Presently, there are many kinds of way to deal with the uranium-containingwastewater, like chemical precipitation, electrochemistry, ion exchange, evaporationenrichment, biosorption process, reverse osmosis, soil infiltration. Foam separation,redox process and so on. However, these conventional methods have manyshortcomings and insufficiency, such as lengthy complex technological process,operation cumbersome. Besides, it has less efficient, relatively high cost andsecondary pollution when we use the conventional methods to deal with lowconcentration of uranium-containing wastewater. Therefore, a new method oftechnology to recovery and recycle uranium from uranium-containing wastewatershould be expected to be developed.The treatment and recovery of uranium-containing wastewater using LiquidMembrane Emulsion（LME） was studied in this paper, which contained the bestvolume ratio of Membrane materials, stirring speed during emulsion process; theconditions of extracting, such as temperature, pH, initial concentration of UO22+.Moreover, the mechanism for extracting UO22+was also discussed. The resultsshowed that this process can happen spontaneously, which was interpretedtheoretically through a thermodynamic model. Through research and analysis, thefollowing conclusions were drew:（1）The best experimental condition of emulsifying were as follows:â‘ Emulsionsystem made up of10%P₂₀₄-6%span80-79%sulphonated kerosene-5%liquidparaffin;â‘¡stirring speed control in2000r/min;â‘¢the concentration of Inner Phase was4mol·L^-1.The breakage rate under the above condition less then1%within an hour,and the recovery rate more then90%.（2） The recovery rate of uranium was up to90%, through the LME extracted theUO22+half an hour at pH2.5at room temperature when the initial concentration wasless than400mg·L^-1, the uranium-containing wastewater and LME with the volumeratio of5:1.（3）The mechanism of experimental process is that the hydrogen atom in hydroxyof P₂₀₄（flow carriers） swaped with UO22+, and formed complex compounds whichentered into the inner phase. Then the complex compounds were back extrationbecause of high concentration of H+in the inner phase. After desorption, P₂₀₄（flowcarriers） went back to the membrane phase, and taken the next complexing.（4）The results showed that the reaction process was spontaneous by calculatingGibbs free energy of inside and outside membrane.