Arsenic Adsorption onto Minerals: Connecting Experimental Observations with Density Functional Theory Calculations

A review of the literature about calculating the adsorption properties of arsenic onto mineral models using density functional theory (DFT) is presented. Furthermore, this work presents DFT results that show the effect of model charge, hydration, oxidation state, and DFT method on the structures and adsorption energies for As-III and As-V onto Fe3+-(oxyhydr) oxide cluster models. Calculated interatomic distances from periodic planewave and cluster-model DFT are compared with experimental data for As-III and As-V adsorbed to Fe3+-(oxyhydr) oxide models. In addition, reaction rates for the adsorption of As-V on alpha-FeOOH (goethite) (010) and Fe3+ (oxyhydr) oxide cluster models were calculated using planewave and cluster-model DFT methods.