Microwave-assisted functionalization of Rosa Canina-L fruits activated carbon with tetraethylenepentamine and its adsorption behavior toward Ni(II) in aqueous solution: Kinetic, equilibrium and thermodynamic studies

This paper investigates the ability of the tetraethylenepentamine-functionalized Rosa Canina-L fruits activated carbon (TEPFRCA) prepared by microwave-assisted technique to remove Ni(II) from an aqueous solution. The activated carbon was prepared by concentrated H2SO4 and was characterized using the FE-SEM, FTIR and N-2 adsorption-desorption isotherms. The batch method was performed by varying the contact time (0-60 min), initial metal ion concentration (50-500 mg/L), temperature (298-333 K), adsorbent dose (0.05-0.15 g) and initial pH (2-8) of the solution. The adsorption process follows pseudo-second-order reaction kinetics. The equilibrium data were fitted well by the Langmuir and Freundlich model. The monolayer adsorption capacities were found to be 128.205,135.135 and 140.845 mg/g at 298,318 and 333 K, respectively. Thermodynamic parameters such as Delta G degrees, Delta H degrees and Delta S degrees were also calculated. The adsorption of Ni(II) on TEPFRCA was found to be spontaneous and endothermic under standard conditions. The positive value of Delta S degrees showed that Ni(II) adsorption caused the randomness in the system. The maximum Ni(II) recovery efficiencies were 65.1% and 62.7% for 0.1 HNO3 and 0.1 HCl, respectively. The results showed that TEPFRCA can be used as a low cost adsorbent for the removal of Ni(11) from aqueous solutions. (C) 2014 Elsevier B.V. All rights reserved.