Determining granular activated carbon adsorption isotherms of benzene as avolatile organic compound

The determination of the adsorption equilibrium isotherm is a fundamental r equirement for the design of adsorption-based processes. A method using a h eadspace auto-sampler and gas chromatograph system was developed in this st udy to determine the adsorption isotherm of benzene as a volatile organic c ompound for granular activated carbon. Dynamic equilibria between chemical solution, headspace gas and activated carbon were established in the 22-mL headspace glass vials sealed with Teflon-faced silicone septa and aluminum cramp caps. Using the closed system of headspace glass vials minimized the volatilization loss of chemical during the experiment. The method was utili zed to measure the adsorption of benzene on Filtrasorb 300 granular activat ed carbon under 25 +/- 1 degrees C. The Freundlich isotherm parameters were determined using the experimental result. A reproducibility study and comp arison with other results found in the literature showed that the method de veloped in this research is a reliable technique for determination of adsor ption isotherm of benzene as a volatile organic compound on activated carbo n.