TWO-PARAMETER ISOTHERMS OF METHYL ORANGE SORPTION BY PINECONE DERIVED ACTIVATED CARBON

The adsorption of a mono azo dye methyl-orange (meo) onto granular pinecone derived activated carbon (gpac), from aqueous solutions, was studied in a batch system. seven two-parameter isotherm models of langmuir, freundlich, dubinin-radushkevic, temkin, halsey, jovanovic and hurkins-jura were used to fit the experimental data. the results revealed that the adsorption isotherm models fitted the data in the order of jovanovic (x2=1.374) > langmuir > dubinin-radushkevic > temkin > freundlich > halsey > hurkins-jura isotherms. adsorption isotherms modeling showed that the interaction of dye with activated carbon surface is localized monolayer adsorption. a comparison of kinetic models was evaluated for the pseudo-second order, elovich and lagergren kinetic models. lagergren first order model was found to agree well with the experimental data (x2=9.231). in order to determine the best-fit isotherm and kinetic models, two error analysis methods of residual mean square error and chi-square statistic (x2) were used to evaluate the data.