Journal of Colloid and Interface Science, Vol.188, No.2, 340-350, 1997
Transport Model for the Adsorption of Oxyanions of Selenium(IV) and Arsenic(V) from Water Onto Lanthanum-Based and Aluminum-Based Oxides
A model for the adsorption of oxyanions of selenium (IV) and arsenic (V) as a function of time and pH was developed and tested on LA(T) (10% lanthanum oxide/90% activated gamma-alumina mixed-oxide), lanthanum oxide, activated gamma-alumina, and activated alpha-alumina. A good correlation between the transport model and experimental results were observed. The model showed strong evidence that the adsorption of oxyanions of selenium and arsenic at the oxide-water interface is governed by three gradients : concentration, potential, and ionic size. Lanthanum oxide was observed to be a better adsorbent for selenium than activated gamma-alumina and alpha-alumina. At the same initial selenium concentration, gamma-alumina was a better adsorbent for selenium as compared to alpha-alumina.