Thermodynamic and kinetic investigations of uranium adsorption on soil

In order to understand the mobility of uranium it is very important to know about its sorption kinetics and the thermodynamics behind the sorption process on soil. In the present study the sorption kinetics of uranium was studied in soil and the influence parameters to the sorption process, such as initial uranium concentration, pH, contact time and temperature were investigated. Distribution coefficient of uranium on soil was measured by laboratory batch method. Experimental isotherms evaluated from the distribution coefficients were fit to Langmuir, Freundlich and Dubinin-Radushkevich (D-R) models. The sorption energy for uranium from the D-R adsorption isotherm was calculated to be 7.07 kJ mol(-1).The values of Delta H and Delta S were calculated to be 37.33 kJ mol(-1) and 162 J K-1 mol(-1), respectively. Delta G at 30 A degrees C was estimated to be -11.76 kJ mol(-1). From sorption kinetics of uranium the reaction rate was calculated to be 1.6 x 10(-3) min(-1).