Adsorption of C.I. Basic Blue 9 on cyclodextrin-based material containing carboxylic groups

Cyclodextrin-based materials containing carboxylic groups (CD/CMC adsorbents) are used for the removal of C.I. Basic Blue 9 (BB 9) from aqueous solutions. Studies concerning the sorption kinetics (i.e. the effects of contact time, dye concentration and mass of sorbent) are presented and discussed. Results of adsorption experiments showed that these adsorbents exhibited high sorption capacities toward C.I. Basic Blue 9. The adsorption capacity of BB 9 on CD/CMC material increased as the dosage of the material increased and the adsorption kinetics followed a pseudo-second order model. However, the sorption was dependent on the presence of carboxylic groups. Four isotherm equations have been tested in the present study, namely Freundlich, Langmuir, Temkin and generalized. The characteristic parameters for each isotherm have been determined. The monolayer adsorption capacity was 56.5 mg g−1. The Freundlich equation represented the best fit of experimental data than the other isotherm equations.