Removal of basic green 5 by carbonaceous adsorbent: Adsorption kinetics

Abstract

The Eucalyptus lenceolata wood was collected from Malakand division, Khyber Pakhtunkhwa Pakistan. Chemical activation of sample was conducted for surface efficiency. Batch studies were performed to address various experimental parameters like, contact time, temperature and adsorbent dosage for the removal of dye. For elemental analysis, surface morphology and for identification of different functional groups, energy dispersive spectroscopy (EDS), scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) techniques were applied, respectively. Removal of dye (Basic Green 5) was studied on raw and activated samples by kinetics adsorption at different temperature. BET adsorption isotherm was used to characterize the surface area of the sample. Under the conditions investigated, a higher carbonization temperature promoted development of porous structures. Intraparticle diffusion, Elovich and Bhangam models were used for adsorption kinetics studies. From adsorption kinetic data thermodynamic parameters like ΔH^≠, ΔS^≠ and ΔE^≠ were determined. The results show that the adsorption is spontaneous process. The endothermic nature of adsorptive process is due to the positive value of enthalpy. The negative entropy shows that acids molecules on the surface of adsorbent take an oriented position. The results shows that all the models were best fitted for these data of adsorption.

KEY WORDS: Activated carbon, Adsorption, SEM, EDS, FTIR, Surface area

Bull. Chem. Soc. Ethiop. 2017, 31(3), 411-422. 

DOI: http://dx.doi.org/10.4314/bcse.v31i3.5