Adsorption of Eu(III) from aqueous solution using mesoporous molecular sieve

The adsorption behavior of Eu(III) from aqueous solution to mesoporous molecular sieves (Al-MCM-41) is investigated as a function of contact time, solid content, ionic strength, pH, foreign ions and temperature by using batch technique. The experimental results show that Eu(III) adsorption is strongly dependent on pH values, but independent of ionic strength and foreign cations under our experimental conditions. The kinetic process is described by a pseudo-second-order rate model very well. The adsorption isotherms are simulated by Langmuir model very well. The thermodynamic parameters (∆G°, ∆S°, ∆H°) are calculated from the temperature dependent adsorption isotherms at 293, 313 and 333 K, respectively, and the results suggest that the adsorption of Eu(III) on Al-MCM-41 is a spontaneous and endothermic process. Desorption studies indicate that the adsorbed Eu(III) is very difficult to be desorbed from the solid surface. Al-MCM-41 is a suitable material for the preconcentration and solidification of Eu(III) from large volumes of aqueous solutions.