Abstract
By using an electrodialysis cell with 4 chambers of which effective membrane area was 12.6cm<USP>2</USP>, between 10 to 40A/m<USP>2</USP> of current density was measured selectivity of multivalenced metal cations (B) such as Co<USP>2+</USP>, Cr<USP>3+</USP> and Fe<USP>3+</USP> to Na<USP>+</USP> through two types of commercially available cation exchange membranes CMV and C66-5T, and two types of self made heterogeneous cation exchange resin membrane and chelating resin membrane. (T<USP>B</USP><USB>Na</USB>)<USB>i=0</USB> at zero current density wascalculated by using the concentration of each metal cation in the membrane equilibriated with aqueous solution of mixed metal ions and transference of each metal ion calculated based on membrane potential between two aqueous mixed solutions of different concentrations.
T<USP>B</USP><USB>Na</USB> for Co<USP>2+</USP> and Fe<USP>3+</USP> may be expressed by the following equation:
T<USP>B</USP><USB>Na</USB>(i)=(T<USP>B</USP><USB>Na</USB>)<USB>i=∞</USB>+ {(T<USP>B</USP><USB>Na</USB>)<USB>i=0</USB>-(T<USP>B</USP><USB>Na</USB>)<USB>i=∞</USB>} e<USP>-βi</USP>
where (T<USP>B</USP><USB>Na</USB>)<USB>i=∞</USB> is a ratio of mobility of ion B to that of Na<USP>+</USP> in aqueous solution.
