Mixed-bed deionization of 0.0002 to 0.01N sodium chloride solutions at flow rates in the range of 3 to 70 gal./(min.) (sq. ft.) with bed depths of 0.25 to 3.2 ft. was investigated. The rate of ion exchange was found to be limited by a liquid-film mass transfer mechanism in the high purity water range (< 1 μ micromho/cm. effluent conductivity).

The magnitude of the temperature effect in the range 15° to 45°C. is given. Methods for prediction of effect of both changes in particle size distribution and incomplete regeneration of the component ion exchange resins are presented. A tentative correlation is given which estimates the effect of solute and solvent species.