DETERMINATION OF SPECIFIC SURFACE-AREA OF GRANULAR ACTIVATED CARBON BY AQUEOUS PHASE ADSORPTION OF PHENOL AND FROM PORE-SIZE DISTRIBUTION MEASUREMENTS

Adsorption of phenol from the aqueous phase onto six grades of granular activated carbon (GAC) was studied at 35-degrees-C. The adsorption equilibrium data for all the GAC-phenol systems were analyzed by Langmuir, BET, and John's adsorption isotherm equations to estimate the specific surface area of each adsorbent. Pore size distribution measurements were also carried out for all the GAC samples. The surface area values obtained by both Langmuir and BET methods are in close agreement in the micromolar concentration range such as those present in wastewater. Pore size distribution measurement shows that for all the GAC samples used in this investigation, more than 97% of the surface area is located in the micropores below 35 angstrom in radius.