Application of γ-Nanoalumina-based Kaolinitic Clay (Na-Kc) in the Adsorptive Removal of Basic Blue 9 from aqueous synthetic Solution

Abstract

Experimental and theoretical investigations related to the adsorptive removal of Basic blue 9 (BB9) onto γ-nanoAl2O3 have been done in the present work. Batch tests were carried out varying some processing parameters namely initial dye concentration (5 - 50 mg/L), adsorbent dose (0.5 - 5 g/L), initial pH (1 - 12) and contact time (0 - 30 min). Under conditions of C0 = 50 mg/L; pH = 11; dose = 1g/L and t = 15 min, more than 83.6% of the BB9 molecules were removed. The pseudo-second order and the Langmuir models fit well the experimental data with highest R2 values of 0.99 and 0.91 respectively and lowest values of χ2. This suggests a two- step mechanism on a homogeneous distribution of active sites on the adsorbent surface. The adsorption mechanism first involved electrostatic interactions between the negatively charged γ-nanoAl2O3 surface in basic medium and secondly electrophilic-nucleophilic interactions. Compared to other adsorbents, γ-nanoAl2O3 of this work is a good alternative for treatment water containing dye BB9.