Fixed-bed modeling of arsenic (III) adsorption from water by Sulfate Modified Iron Oxide Coated Sand (SMIOCS)

Abstract
A medium known as sulfate modified iron oxide coated sand (SMIOCS) was evaluated for the removal of As (III) from synthetic water with ionic strength of 0.01 M NaNO ₃ employing fixed bed mode. The medium was characterised for BET surface area; alkali and acid resistance; and presence of iron, barium and sulfur on sand surface. The particle size of media shown significant impact on bed volume treated with similar expcrimental protocol. A theoretical model, Wolborska model, has shown good correlation with observed experimental data generated during depth variation studies at flow rate of 1.56 m ³/m ²/hr with influent As (III) concentration of 1.0 mg/L. Regeneration studies using 0.2 M NaOH as regenerant resulted in nearly 83% recove of As (III) during up flow mode.