Mechanism and equilibrium modeling of Re and Mo adsorption on a gel type strong base anion resin

Resumo

A static-batch technique was used to demonstrate the adsorption behavior of Re (VII) and Mo ions onto Dowex 21K at equilibrium in single and binary component systems. The single equilibrium adsorption data were modeled through a linear form of four widely used equilibrium isotherm equations. The results indicated that Freundlich and D-R models for Re, and Temkin and D–R isotherms for Mo fitted the obtained data satisfactorily. Binary adsorptions of Re and Mo ions onto Dowex 21K were also analyzed using Extended Langmuir, Modified Langmuir, Extended Freundlich and Langmuir–Freundlich models. The competitive Extended Freundlich model fitted the binary adsorption equilibrium data adequately. Studies on mutual interference effects of Mo ions on Re adsorption capacity indicated that the adsorption of perrhenate ions is always suppressed. In this perspective, the results from EDX studies confirmed the rhenium atom decrease in the simulated Re–Mo adsorption. However, under the studied conditions the affinity of the Dowex 21K for rhenium ions is marginally greater than that of molybdenum ions.