Treatment of arsenic-rich waters using granular iron hydroxides

摘要

The granular media, ferric hydroxides (CFH12), was applied to remove arsenic species from aqueous solutions. The CFH12 was characterized in terms of its composition, moisture content, bulk density, particle size, pH of zero point charge and specific surface area. The kinetics and equilibrium adsorption studies were conducted to determine the efficiency of the tested granular iron-based material in As(III) and As(V) removal. The equilibrium studies demonstrated that both the Langmuir and Freundlich isotherm model described the adsorption of arsenic species notably well with high correlation coefficients. The maximum adsorption capacity of As(V) onto CFH12 estimated by the Langmuir model was comparable to As(III). The results obtained from the kinetics adsorption tests demonstrated a significantly higher removal rate of As(V) than As(III) and indicated the benefits of applying granular ferric hydroxides in the treatment of even highly arsenic-contaminated waters.