AWWA WQTC52783

Basic transport phenomena of various ions are importantfor the application of ion-exchange membranes (IEMs). Several studies on the development of mathematical models for predicting membrane transport have been performed. By using the principles of irreversible thermodynamics, various transport equations have been derived which describe non-stationary diffusion through membrane separating pores. Interactions among various anions and the membrane pore/surface were evaluated in terms of selectivity/adsorptivity andtransmissibility of the solutes in membranes. Relative selectivity of each anion for a membrane was determined by adsorption tests and resulting isotherms, as performed with an adsorption cell. Transmissibility of various anions through membrane pores was determinedto obtain their diffusivities and mass transfer coefficients. Affinity coefficients determined from selectivity tests and mass transfer coefficients of the anions were anticipated to be used for membrane performance prediction. The characteristics of anions were investigated rigorously to relate their transport phenomena near the membrane surface and their treatability. Includes 3 references, tables, figures.