Removal of antimony (III) using polyol-ligand-containing porous hollow-fiber membranes

A polyol-ligand-containing porous hollow-fiber membrane capable of removing antimony (III) from a liquid stream was prepared by radiation-induced graft polymerization of an epoxy-group-containing vinyl monomer, glycidyl methacrylate (GMA), and subsequent functionalization with N-methylglucamine (NMG) and 3-amino-1,2-propanediol (APD). The resultant chelate-forming group density was 1.6 mol per kg of the NMG-group-containing porous hollow-fiber membrane. An antimony (III) oxide solution (10 mg per L, pH 3.6-13) was forced to permeate through the submicron-diameter pores of the chelating porous hollow-fiber membrane. The antimony concentration of the effluent penetrating the outside surface of the hollow fiber was determined as a function of the effluent volume. The breakthrough or dynamic adsorption capacity for antimony was 54 g of Sb per kg of membrane at pH 11. Because of negligible diffusional mass-transfer resistance, the breakthrough curves overlapped irrespective of the permeation rate of the antimony solution across the chelating porous hollow-fiber membranes.