FURI | Spring 2021

Investigation on the Adsorption of Selenium Oxo-Anions on Hematite and Alumina Surfaces

Selenium oxo-anions are toxic substances present in drinking water, these can be removed by using Hematite and Alumina as the adsorbent materials. Density Functional Theory is used to understand the factors affecting the adsorption. Alumina and Hematite have the same crystal structure, allowing to probe composition-dependent effects. The results indicate that outer-sphere adsorption is stronger than inner-sphere adsorption for both adsorbents. However, Hematite is selective to Selenite while Alumina is selective to Selenate. Also, semi-protonated systems have higher adsorption energies for Hematite while deprotonated systems have higher adsorption energies for Alumina. These factors are important in designing selective models for effective adsorption.