Adsorption characteristics of a low cost activated carbon for the removal of Victoria blue from aqueous solutions

Abstract

The adsorption of victoria blue by a low cost activated carbon synthesized from agro waste lemon grass was investigated. Activated carbon was prepared in the atmosphere of nitrogen and then characterized by BET surface area, X-ray Diffraction, Fourier Transformation Infrared (FTIR) spectroscopy, and Scanning Electron Microscopy (SEM) . Removal of the selected dye victoria blue (VB) onto lemon grass activated carbon (LGAC) was conducted. BET surface area of LGAC was found to be ~218 m2/g. Effect of initial concentration and contact time of dye, pH and temperature on the removal was investigated. Alkaline pH range favoured removal of VB. Maximum removal of the dye was found to be 90% under optimum conditions. Kinetics of removal process has been studied and mass transfer coefficient and intra-particle diffusion constant were also determined for removal of the dye at different temperatures. Value of be rate constant for the removal was found to be 1.40×10-2 min-1 at dye concentration of 1.53x10-2 at 30°C. Increasing the temperature increased the removal of the dye, indicating the endothermic nature of the process of removal. Langmuir and Freundlich isotherm constants were determined and revealed that LGAC is a proper adsorbent material for the removal of VB from aqueous solution.