Kinetics and Mechanism of Exchange SORPTION OF Fe(III) in Aqueous and Aqueous-Organic Media

Dr. Kh. A. S. Ghaleb and Dr. Ali A. Mutair

الملخص

Studies have been made on the kinetics and mechanism of exchange sorption of Fe(III) on m-cresol-phenol formaldehyde (H+ -from), using modified limited batch technique in aqueous and aqueous-isopropanol media. The sorption of Fe(III) was found to be markedly affected by the change of dielectric constant of all the systems studied here in. Using an equation of the Arrhenius type Di/D0 = exp-Ea/RT, the values of activation energies were found to be 3.71 , 3.56 , 3.31 and 3.08 K cal/mole in case of 0.0 , 30.60 and 80% (v/v) isopropanol respectively. The increase in the exchange rate with decreasing resin particle size (0.031-0.022 cm) and with increasing the temperature (25-60 o c) has been discussed. Diffusion of ferric ion through the solid phase is found to be the rate-determining step in the exchange process. The negative values of ∆S * have been taken as indicative of a comparatively higher degree of mobility and the lack of an orientational effect.