Amine-Functionalized MWCNTs for the Removal of Mordant Black 11 Dye

In this study, amine-functionalized MWCNTs ( f -MWCNTs) have been investigated as potential material for the removal of Mordant black dye 11 (MBD 11). To evaluate the optimal condition and adsorption capability of the adsorbents ( f -MWCNTs), the effect of temperature, pH, adsorbent dosage, and contact time on adsorption rate are examined. The study shows a stronger interaction between the dye and f -MWCNTs. The highest removal efficiency is observed in acidic medium (pH 2) with an initial dye concentration of 50 mg L −1 , where 99% of the dye is adsorbed from the medium in 40 min using 0.05 g of f -MWCNTs. Adsorption isotherm and kinetic studies reveal that adsorption occurs by the Langmuir adsorption model and pseudo-second-order adsorption kinetics. According to the thermodynamic parameters, the adsorption exhibits endothermic and spontaneous behavior. Graphical Abstract