Electrical conductivity of a flexible resin loaded with Cr (III) ions

Electrical conductivity of flexible strongly acidic resin loaded with Cr (III) was investigated with an impedance spectroscopy method. The purpose of the work was to estimate the influence of hydrostatic pressure drop on the conductivity of the ion-exchanger bed, which had been compacted previously. The dependence of the electrical conductivity on pressure was found to obey the logarithmic law. The effect of pressure on the conductivity becomes stronger with increase of loading degree and also shrinkage of the resin. The conductivity increases 2.5 times with increase in pressure drop from 2 )/103 to 5 )/104 Pa, when the resin contains high amount of Cr (III) on the one hand and additionally sorbed electrolyte has been previously removed. The apparent contribution of convection to the total conductivity was determined, the convection conductivity was found to increase with increase in pressure. At the same time the conductivity caused by migration remains without any changes.

The dependence of the electrical conductivity of previously compacted bed of strongly acidic flexible ion-exchanger on hydrostatic pressure drop was found to obey the logarithmic law. The influence of pressure on the conductivity becomes stronger with increasing in loading degree and correspondingly shrinkage of the resin. The conductivity increases in 2.5 times with increasing in pressure drop from 2 )103 to 5 )104 Pa. when the resin contains high amount / / / / / / / / / / c d F f l DP S ¯ u ¯ uo ¯ Xi empirical coefficient (Ohm(1 m(1) empirical coefficient (Ohm(1 m(1 Pa(1) concentration of species in ionexchanger (mol m(3) empirical coefficient (Ohm(1 m(1) empirical coefficient (Ohm(1 m(1) Faraday’s constant (A s mol(1) empirical coefficient (Ohm(1 m(1 Pa(1) distance between electrodes (m) pressure drop (Pa) effective electrode area (m2) mobility of species in ion-exchanger (m2 V(1s(1) rate of intraporous liquid (m s(1) concentration of fixed charges (mol m(3) Y? z / / / / / / real part of admittance (Ohm(1) valency (dimensionless) Greeks  ¯ specific dc conductivity of ionexchanger (Ohm(1 m(1) c ¯ conductivity of ion-exchanger caused by convection (Ohm(1 m(1) m ¯ conductivity of ion-exchanger caused by migration (Ohm(1 m(1) D’ streaming potential (V) o ¯ specific flow resistance of the ionexchanger (kg m(3 s(1) ! fractional pore volume (dimensionless)