1988 年 13 巻 5 号 p. 272-282
Many methods of recovery of uranium from seawater have been suggested : coprecipitation, adsorption, ion flotation, solvent extraction, and others. Of these, only the adsorption method using a suitable solid adsorbent seems to be feasible with regard to economic and envirom ental impacts. Extensive investigations of adsorbents have been carried out. Among the various organic resins, chelating resins containing amidoxime groups have been selected. A novel amidoxime-group-containing adsorbent of hollow-fiber form was prepared by radiation-induced graft polymerization of acrylonitrile onto a polyethylene hollow fiber, followed by chemical conversion of the produced cyano group to an amidoxime group. The fixed-bed adsorption column, 30 cm in length and charged with the bundle of amidoxime hollow-fibers, was found to adsorb uranium from seawater at a sufficiently high rate : 0.66 mg uranium per g of adsorbent in 25 days.