Kinetic, isotherm and thermodynamic studies of the adsorption of crystal violet by activated carbon from peanut shells

• Published in: Water science and technology Vol. 67; no. 4; pp. 737 - 744
• Main Authors: ZHANG, J. X, OU, L. L
• Format: Journal Article
• Language: English
• Published: London International Water Association 01.01.2013; IWA Publishing
• Subjects: Activated carbon; Adsorption; Applied sciences; Arachis; Arachis hypogaea; Charcoal - chemistry; Coefficients; Constants; Correlation coefficient; Correlation coefficients; Crystals; Dyes; Endothermic reactions; Enthalpy; Entropy; Exact sciences and technology; Free energy; Gentian violet; Gentian Violet - chemistry; Gibbs free energy; Isotherms; Kinetics; Mathematical models; Order parameters; Parameters; Particle Size; Pollution; Rate constants; Removal; Shells; Solutions; Temperature; Thermodynamics; Time Factors; Waste Disposal, Fluid - methods; Water Pollutants, Chemical - chemistry; Water treatment and pollution; Thermodynamics; Adsorption; Activated carbon; Shell(anatomy); Isotherm; Kinetics; crystal violet; peanut shells
• ISSN: 0273-1223; 1996-9732
• DOI: 10.2166/wst.2012.605

The adsorption of crystal violet dye from aqueous solutions onto an activated carbon prepared from peanut shells was analyzed in this study. The effects of particle size, initial concentration, time and temperature on crystal violet removal were studied in batch experiments. Experimental results showed that the adsorption equilibrium was achieved within 100 min for all studied concentrations. Analysis of adsorption results showed that the adsorption isotherms could be well fitted to the Langmuir model. Kinetic parameters, rate constants, equilibrium adsorption capacities and related correlation coefficients for pseudo first-order and second-order kinetic models were calculated and discussed. The results revealed that the adsorption kinetics was in good agreement with the pseudo second-order equation. Thermodynamic parameters such as the change of Gibbs free energy (ΔG°), change of enthalpy (ΔH°) and change of entropy (ΔS°) have also been determined and it has been found that the adsorption process should be spontaneous, endothermic and physisorption in nature.