The Study Of The Adsorption Kinetics And Thermodynamics Of U(?) Onto Red Earth And The Relative Contribution Of The Solid Components

The adsorption characteristics of uranium onto red earth and the relative contribution of the solid components were studied by laser fluorescence method,including natural red earth,metal oxide removed red earth,removed organic matter of red earth,organic material and metal-oxide removed red earth,kaoline.The effects of p H,ionic strength and humic acid on the adsorption of U(?)onto red earth and the relative contribution of the solid components were studied by changing the experimental conditions.Based on macroscopic adsorption experiments,the adsorption process was analyzed by thermodynamics and kinetics,and X-ray diffraction(XRD),scanning electron microscopy(SEM)and infrared spectroscopy(FTIR)were used to characterize the red earth and the relative contribution of the solid components samples.The results show :The influence of red Earth and the relative contribution of the solid components on the adsorption of uranium is the most important influencing factor,and the effect on the adsorption process is significant.The effect of bivalent calcium on the adsorption of U(?)on red Earth and the relative contribution of the solid components was not obvious.The effect of bivalent calcium on the adsorption of U(?)on red Earth and the relative contribution of the solid components was obvious.In a certain range,in the presence of humic acid,the higher the acidity of the suspension,the higher the adsorption effect of U(?)on the red Earth and the relative contribution of the solid components.After reaching a certain value,with the increase of p H,The effect of this adsorption-promoting effect is diminished.The adsorption percentage of U(?)on the red Earth and the relative contribution of the solid components reached a certain value,and its adsorption percentage remained basically unchanged.The adsorption of U(?)onto natural red soil and kaolin reached equilibrium after 10 hours.The adsorption time of U(?)onto removed organic matter of red earth was the shortest,and the adsorption time of U(?)onto organic material and metal-oxide removed red earth was the longest.The adsorption capacity of the metal oxide removed red earth is higher than that of the natural red earth,and the adsorption capacity of the organic material and metal-oxide removed red earth is lower than that of the natural red earth,and the adsorption capacity of kaoline is the smallest.The metal oxide inhibits the adsorption process,and the organic matter promotes the adsorption process.In the process of adsorption of red earth and the relative contribution of the solid components,the adsorption process including surface adsorption and internal particles is a complicated process.High temperature is favorable for the adsorption of U(?)onto red earth and the relative contribution of the solid components.The effect of temperature to the adsorption of U(?)onto metal oxide removed red earth and removed organic matter of red earth and organic material and metal-oxide removed red earth is the same.The effect of temperature to the adsorption of U(?)onto natural red earth is the highest.The effect of temperature to the adsorption of U(?)onto kaoline is minimal.