Open AccessION EXCHANGE MECHANISM OF Cr+3 ON NATURALLY OCCURRING CLINOPTILOLITE
Author(s) -
Maria Angélica Simões Dornellas de Barros,
Nádia Regina Camargo Fernandes Machado,
F.V. Alves,
Eduardo Falabella Sousa-Aguiar
Publication year - 1997
Publication title -
brazilian journal of chemical engineering/brazilian journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.313
H-Index - 52
eISSN - 1678-4383
pISSN - 0104-6632
DOI - 10.1590/s0104-66321997000300006
Subject(s) - clinoptilolite , ion exchange , zeolite , mordenite , chemistry , impurity , ion , thermodynamics , materials science , physics , organic chemistry , catalysis
Ion exchange isotherms are very important tools to achieve a better comprehension of cation removal by means of zeolite treatment. In this work, three isotherms were obtained (at 298K, at 313K and at 333K) from natural pretreated Na+ clinoptilolite. The ion exchange was carried out with Cr+3 ions. The isotherms’ shape is similar to the classical type "b" isotherm, according to the arrangement proposed by Breck (1984). Mathematical fitting was applied to the experimental points (Table Curve software) to obtain a representative curve thereof. From such fittings, points were simulated and then used to construct the Kielland plots, whose shape was associated with an ion exchange mechanism. Straight lines were obtained as an indication that, although the zeolite used is of natural occurrence and presents impurities such as mordenite and clays, only one site is involved in the ion exchange proces