BREAKTHROUGH CURVE IN ION EXCHANGE COLUMN

PARTICLE DIFFUSION CONTROL

Abstract

Theoretical breakthrough curves for an ion exchange column are presented for the case where equilibrium constant based on mass action law is infinite and particle diffusion is the rate-controlling step. An effect of the electric field caused by the difference in diffusivity of counter ions on the breakthrough curves is evaluated by applying the Nernst-PIanck equation. Approximate equations are proposed for breakthrough curves whose maximum error from the exact solution is 4%. The theoretical values agree fairly well with experimental results in the R-H-NaOH system (equilibrium constant is infinite) and the R-Na-Ce(NO₃)₃ system (equilibrium constant is finite), respectively.