Abstract
Binary oxidized cactus fruit peel (CFP) was used as adsorbent for the removal of brilliant green (BG). The prepared adsorbent was characterized by Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and Energy dispersive X-ray (EDAX). Batch adsorption studies were performed as a function of contact time, initial solution pH, initial BG concentration and temperature. Initial solution pH alters the adsorbent surface charge and BG structure and optimum adsorption was found at pH 3. Kinetic analysis revealed that adsorption experimental data was best fitted by pseudo-second order model. The equilibrium adsorption data was found to follow the Langmuir isotherm model and maximum monolayer capacity was found to be 166.66 mg g(-1) at 20 degrees C. Thermodynamics of BG adsorption revealed the process was spontaneous and exothermic in nature. The magnitude of enthalpy change (Delta H degrees) was found to be 25.43 kJ/mol, revealed that physical forces were involved in adsorption of BG onto CFP. (C) 2013 Elsevier B.V. All rights reserved.