AS(III) REMOVAL FROM AQUEOUS-SOLUTIONS USING NONSTOICHIOMETRIC COPRECIPITATION WITH IRON(III) SULFATE AND FILTRATION OR FLOTATION

A study of As(III) removal from aqueous solutions was carried out, using iron(III) sulphate as a coprecipitation agent. When the initial As(III) concentration was 3775 mgl(-1), maximum As(III) removal was achieved at pH 9 and with a molar ratio of Fe(III)/As(III) equal to 11. Under these conditions the formed precipitates showed highest stability, relative to the fixation of As(III). Flotation which can be applied as a subsequent solid/liquid separation method, was found to be particularly effective for solutions containing low As(III) concentrations (less than or equal to 10 mg(-1)).