Experimental Study on Adsorption of Arsenic in Aqueous System with Three Iron Oxides

Two synthetic iron oxides including goethite and ferrihydrite as well as hematite were used as sorbent to adsorb the arsenic water sample.Results showed that the effect of ferrihydrite was the best in the initial concentration of 1,200μg/L of arsenic(Ⅲ)solution,but the adsorptive effect of goethite and hematite were relatively poor.In initial pH of 7 and mixed liquid with mol ratio of 1:1 of arsenic(Ⅲ)and arsenic(V),the adsorptive effects of three ion oxides in the mixed liquid reduced as mol ratio of As/Fe increased.In the mixed liquid with mol ratio of 1:1 of arsenic(Ⅲ)and arsenic(V),the best adsorptive effect was goethite,and then followed by ferrihydrite,while hematite showed the worst adsorptive effect.The presence of As(V)has an impact on removal efficiency.The adsorption of three iron oxides is selective under the coexistence of trivalent arsenic and quinquevalent arsenic.