Adsorption studies of basic dyes onto teak (Tectona grandis) leaf powder

Abstract

In this study, the adsorption potential of Teak (Tectona grandis) leaf powder (TLP) to remove Methylene blue (MB) and Malachite Green (MG) dye molecules from aqueous solution was investigated. Batch experiments were conducted to evaluate the influence of operational parameters such as, pH (2−9), adsorbent dosage (1−7 g/L), contact time (15−150 minutes) and initial dye concentration (20−120 mg/L) at stirring speed of 150 rpm for the adsorption of MB and MG on TLP. Maximum removal efficiency of 98.4% and 95.1% was achieved for MB and MG dye, respectively. The experimental equilibrium data were analysed using Langmuir, Freundlich and Temkin isotherm models and it was found that, it fitted well to the Freundlich isotherm model. The surface structure and morphology of the adsorbent was characterized using scanning electron microscopy (SEM) and the presence of functional groups and its interaction with the dye molecules were analysed using Fourier transform infrared spectroscopy (FTIR). Based on the investigation, it has been demonstrated that the teak leaf powder has good potential for effective adsorption of methylene blue and malachite green dye.