Modeling studies on simultaneous adsorption of phenol and resorcinol onto granular activated carbon from simulated aqueous solution

The modelling study on simultaneous adsorption of phenol and resorcinol onto granular activated carbon (GAC) in multicomponent solution was carried out at 303 K by conducting batch experiments at initial concentration range of 100-1000 mg/l. Three equilibrium isotherm models for multicomponent adsorption studies were considered. In order to determine the parameters of multicomponent adsorption isotherms, individual adsorption studies of phenol and resorcinol on GAC were also carried out. The experimental data of single and multicomponent adsorption were fitted to these models. The parameters of multicomponent models were estimated using error minimization technique on MATLAB R2007a. It has been observed that for low initial concentration of adsorbate (100-200 mg/l), modified Langmuir model represents the data very well with the adsorption constant (Q0), 216.1, 0.032 and average relative error (ARE) of 8.34, 8.31 for phenol and resorcinol respectively. Whereas, for high initial concentration of adsorbate (400-1000 mg/l), extended Freundlich model represents the data very well with adsorption constant (KF) of 25.41, 24.25 and ARE of 7.0, 6.46 for phenol and resorcinol respectively. The effect of pH of solution, adsorbent dose and initial concentrations of phenol and resorcinol on adsorption behaviour was also investigated.