BIOSORPTION OF CRYSTAL VIOLET FROM AQUEOUS SOLUTION BY Citrullus lanatus (WATERMELON) RIND

The efficiency of Citrullus lanatus (Watermelon) rind, an agricultural solid waste was investigated in this study as a novel adsorbent for the removal of Crystal Violet (CV) from aqueous solution. Batch mode experiments were conducted to study the effects of contact time, dose of adsorbent, pH and temperature. Equilibrium data were analyzed using the Langmuir and Freundlich isotherms. Different thermodynamic parameters, like Gibb’s free energy ( G), enthalpy ( H) and entropy ( S) of the adsorption process have also been evaluated. The thermodynamic parameters of CV biosorption indicated that the process is spontaneous and endothermic. Two simplified kinetic models including pseudo-first-order and pseudo-second-order equation were selected to follow the adsorption process. The pseudo-second-order kinetics was the best for the adsorption of CV by Citrullus lanatus rind with good correlation. The results demonstrate that the biosorbent used in this study was found to be a promising material for adsorption of CV from aqueous solutions.