Competitive and Hindering Effects of Natural Organic Matter on the Adsorption of MTBE onto Activated Carbons and Zeolites

Abstract

Equilibrium and kinetic adsorption of methyl tert-butyl ether (MTBE) onto three coal-based activated carbons, one coconut-based activated carbon, and two zeolites are elucidated in this study. Natural organic matter (NOM) and MTBE competed for the adsorption of activated carbons to different extents. The ideal adsorbed solution theory (IAST) combined with the equivalent background compound (EBC) model can adequately describe the NOM competition and predict the isotherms of MTBE onto the activated carbons. No competitive adsorption was observed for one of the zeolites, mordenite, due to the molecular effect. Besides, the aperture size, and the SiO2/Al2O3 ratio of the zeolite may also play an important role in the adsorption of MTBE from the aqueous phase. The surface diffusion model accurately simulated the transport of MTBE within the adsorbents employed in different water matrices. For all the activated carbons tested, the surface diffusivity of MTBE in natural water was nearly equal to that in deionized water, indicating that no apparently hindering effect occurs. A much slower adsorption kinetic of mordenite in natural water was observed since the opening apertures on mordenite may be appreciably hindered and blocked by NOM.

Adsorptive Removal of Volatile Organic Contaminants from Aqueous Medium by Granular Activated Carbons

“…These results indicate that the adsorption of DCM and MTBE on GACs was multilayer adsorption. The results were in good agreement with the results reported elsewhere (Hung et al, 2005).…”

Adsorption of DCM and MTBE from Aqueous Phase on Granular Activated Carbons: A Comparative Study

“…The GACs derived from pecan and almond shells have been successfully tested for the removal of DCM (Bansode et al, 2003). Hung and coworkers had reported adsorptive removal of MTBE onto GAC derived from coconut shell (Hung et al, 2005). These studies motivated us to test and compare the feasibility of two commercially available GACs i.e.…”

Adsorption of MTBE from contaminated water by carbonaceous resins and mordenite zeolite

“…5. For comparison, the figure also includes the experimental data of MTBE in deionized water, STL groundwater and DG River water from the study of Hung et al [30]. The results revealed that the experimental data in natural waters for different initial concentrations were nearly identical with the solid line, the single-solute Freundlich isotherm, indicating that NOM did not compete with MTBE for the adsorption sites.…”

“…For comparison, Fig. 7 also includes the experimental data of MTBE in deionized water and STL groundwater from the study of Hung et al [30]. The Freundlich isotherm in deionized water was directly used in the model.…”