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

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.