Investigation of adsorption characterization of U(VI) ion on modified Amberlite XAD-4 resin with a acidic ligand
Paper ID : 1150-MST2015-FULL
Zahra Shiri-Yekta *
Zahra Shiri-Yekta Ph.D. Nuclear Science and Technology Research Institute (NSTRI) Nuclear Science Research School P. O. Box 11365/8486 Tehran IRAN
Uranium is one of the emerging pollutants due to its high toxicity and radioactivity and most recently its persistence in environment [1]. With due attention to this instance preconcentration and determination of this element in environmental samples (such as drinking and wastewaters) is an important task. Solid phase adsorbents are very useful for preconcentration and separation of this ion, because of their good physical properties such as their porosity, high surface area and good adsorbent properties for great amounts of uncharged compounds. Therefore, in this report, the procedure is based on the adsorption of U(VI) ions on the Amberlite XAD-4 resin loaded with synthesized Schiff base bis(2-hydroxybenzaldehyde)-1,2-ethylendiimine prior to their determination by inductive coupled plasma-mass spectrometry (ICP). The effect of parameters influencing the adsorption efficiency such as aqueous phase pH, contact time, initial metal ions concentration, adsorbent dosage and temperature dependency of the process was verified and discussed. Under optimal conditions (pH 6, adsorbent dosage 0.1 g, contact time 60 min. and 20oC) for uranium ions (initial concentration 20 mg/l) were quantitatively removed from 20 ml of sample solution. Comparison of the adsorption efficiency of the studied resin loaded with a Schiff base with those unloaded ones shows a shift for uptake of the metal ions vs. pH curves towards lower pH values by applying the loaded resin with Schiff base (ΔpH0.5=0.6). The kinetic data corresponds well to the pseudo-second-order equation. This model predicts chemisorption for the adsorption. The adsorption data for studied ion were well fitted by the Frundlich isotherm. Thermodynamic investigation reveals the adsorption process of the studied ion is entropy driven.
U(VI), XAD-4 resin, adsorption, Schiff base
Status : Paper Accepted (Poster Presentation)