Adsorption of arsenate and arsenite anions from aqueous medium by using metal(III)-loaded amberlite resins

Abstract

In this paper, we studied the feasibility of using La(III)-, Ce(III)-, Y(III)-, Fe(III)- and Al(III)-loaded 200CT resin as adsorbents for the removal of As(III and V) from aqueous solution. The effects of the contact time, pH of solution and initial concentration of solution on the removal of As(III and V) were investigated in a batch system in order to explain the adsorption mechanism. The removal of As(III and V) by using metal(III)-loaded 200CT resins are strictly pH-dependent. The reaction mechanism was discussed and followed an ion exchange adsorption mechanism. The kinetics of As(III) adsorption with Y(III)-200CT and As(V) adsorption with Fe(III)-200CT can be described well by the pseudo-first-order and second-order models. The equilibrium adsorption data were fitted by four isotherm models. The fitting results suggested that the Y(III)- and Ce(III)-200CT resins are better adsorbents for the As(III) adsorption and the maximum uptakes are 0.4835 and 0.4592 mol/kg, respectively. And Fe(III)-200CT resin is the best adsorbent for the removal of As(V) with the maximum capacity of 1.450 mol/kg. The coexisting ion influence of PO 4 3− was bigger than SO 4 2− on the removal of As(III and V).