Ultrasound-assisted adsorption of Methyl Parathion using commercial Granular Activated Carbon from aqueous solution

The removal of Methyl parathion (MP) by ultrasound-assisted adsorption using commercial Granular Activated Carbon (GAC) was studied. The effect of sonicate time on the adsorption were studied using the batch technique. The adsorption kinetic data were analyzed using the Pseudo First Order (PFO) and Pseudo Second Order (PSO) models. For kinetic study, the adsorption process fitted the PSO model. Three adsorption isotherms namely the Langmuir, Freundlich and Redlich-Peterson isotherms in their nonlinear forms were applied to the adsorption equilibrium data. Both the Langmuir and Redlich-Peterson models were found to fit the adsorption isotherm data well, but the Redlich- Peterson model was better. The monolayer adsorption capacity, q(m), was found to be 20.20 mg g(-1). It can be concluded that the commercial GAC is an efficient adsorbent for the removal of MP from aqueous solution via ultrasound-assisted adsorption. Attempt to explain the reactivity of MP on GAC by theoretical calculations was made.