Adsorptive removal of volatile organic contaminants from aqueous medium by granular activated carbons

In order to investigate the adsorption of dichloromethane (DCM) and methyl tert-butyl ether (MTBE) form aqueous solution onto granular activated carbons (GACs), kinetics, thermodynamics, and competitive ions studies were carried out. The optimal pH range for the adsorption of DCM and MTBE on GACs was 5.0 to 8.0. Contact time studies showed comparatively lower equilibration time for the adsorption of DCM on GACs. Isotherm studies favored the applicability of Freundlich model. Kinetics studies at different concentrations showed that the adsorption of DCM and MTBE on GACs follow the pseudo-second-order kinetics model. Weber and Morris model showed that the adsorption of MTBE at different concentration on coconut granular activated carbon (CGAC) has intra-particle diffusion as the rate controlling step. The thermodynamics parameters for the adsorption of DCM onto CGAC showed the exothermic nature of the adsorption process. The adsorption of DCM and MTBE on CGAC and wood granular activated carbon (WGAC) was physical adsorption in nature. Competitive ions studies revealed significant potential of CGAC for the removal of DCM even at higher concentrations. �� 2010 Taylor & Francis Group, LLC