Modification Technique Influence on the Adsorption Capability of Organobentonites for Reactive and Direct Dyes

Abstract

In this study, the adsorption of reactive and direct dyes from synthetic textile wastewater using organobentonites modified by two different routes was studied. Except for the drying step, the synthesis conditions were the same, and organobentonites were synthesized by employing a cationic surfactant at a level corresponding to the entire cation exchange capacity of bentonite under microwave irradiation. In the final step, the samples were dried using either a freeze dryer or an air dryer. The structural characteristics of the organobentonites were determined via XRD and FTIR analyses. The obtained equilibrium data indicated that the adsorption process fitted to the Langmuir isotherm model for both dyes. Although the results indicated that both organobentonites adsorbed two of the dyes, the freeze-dried sample could serve as a more effective adsorbent for removing reactive and direct dyes from wastewater.