New Smopex® Ion Exchange Materials for the Removal of Selenium from Industrial Effluent Streams

Abstract

This article discusses new Smopex® ion exchange materials which have been developed by Johnson Matthey Water Technologies, and highlights their performance relative to other commercially available materials for the removal of selenocyanate, selenate and selenite ions from aqueous solutions. The ion exchange mechanisms by which these materials sorb these ions are also explained and modelled in order to highlight the additional benefits that these materials offer that non ion-exchange materials do not, such as the ability to achieve the full material exchange capacities at feed concentrations lower than 1 mg l–1 selenium. The unique characteristics of these fibrous type materials are also discussed, including fast sorption kinetics, facile regeneration and enhanced selectivity for selenium ions against competing sulfate ions. Finally, the performance of these materials in a continuous stirred tank reactor setup is demonstrated, showing that performance levels as high as in fixed bed processes can be achieved, due to the high selectivity and mass transfer kinetics of Smopex® materials.