Physicochemical study of arsenic removal using iron hydroxide

Iron hydroxide (III) synthesized and applied to remove the As (III) and As (V). The optimum pH on the adsorption is between pH 4 and pH 9. Experiments were performed to study the effect of pH and the contact time (T) on the Co precipitation- sorption of Arsenic (III) and Iron (III) Hydroxides. Several co-precipitation experiments are performed with 120 mg of iron (III), from solutions having a pH ranging from about 4.7 and 9, at time 240 min. In this study, the adsorption of the arsenic (III) on the surface of iron hydroxide (III) is examined by adopting surface complexation model, This model successfully used to describe the adsorption of iron on the metal oxides suppose that this phenomenon occurs through an inner-sphere legend exchange mechanisms with surface functional group ( ≡ FeOH). The results of the study show that the co-precipitation of arsenic (III) with Fe (OH)3 was more dependent on the concentration of iron and H+ ions. Complexation in a monodentate area was more important than the bidentate throughout the pH range studied, but the bidentate complex has important role near pH 8