<p> An optimization study of an intermittent-flow multistage fluidized ion exchange column was performed using a stochastic approximation method. A new type of downcomer, a fluid diode, was designed and employed to alleviate liquid bypassing through the downcomer. The well known ion exchange system, H⁺/Na⁺ exchange on Dowex 50W resin, was used in this work. </p> <p> The volumetric efficiency of the system was optimized with regard to certain column and diode parameters. A maximum volumetric efficiency of 71.8 hr⁻¹ was obtained for the following conditions: </p> <p> average liquid flowrate = 3661 ml/min ; </p> <p> resin flowrate = 56.1 gm/min ; </p> <p> plate spacing 11.43 cm ; </p> <p> lateral diode displacement= 0.794 cm. </p> <p> Experiments have shown that a 78.2% increase in volumetric efficiency was achieved by use of the fluidic diode downcomers. </p> / Thesis / Master of Engineering (ME)