Modeling of an adsorption unit packed with amidoxime fiber balls for the recovery of uranium from seawater

Amidoxime fiber adsorbents are prepared by treating commercial poly(acrylonitrile) fibers with NH sub 2 OH in methanol and then with an aqueous NaOH solution. The rate of adsorption of uranium from seawater is 0.1-0.3 (g of U/kg of dry fiber)/day. The fiber is placed in 2 cm diameter spherical shells of plastic net, and these fibrous balls are packed in a column. Seawater is assumed to flow through the packed bed by the kinetic force of the ocean current. The permeation velocity of liquid in each ball is evaluated with a small electrode that detects the electrochemical limiting current. When the permeation velocity is slow, most uranyl ions are adsorbed only in the peripheral part of the ball. A model of the packed bed adsorption unit is proposed, and a numerical caculation gives optimum values of design parameters. Graphs. 24 ref.--AA