CHARACTERIZATION OF MODIFIED ACTIVE CARBONS BY ADSORPTION OF PURE WATER AND BENZENE VAPORS AND TERNARY LIQUID-MIXTURE BENZENE PLUS DIETHYL KETONE PLUS N-HEPTANE

Thermally treated and oxidized active carbon samples were investigated . The chemical character of active carbon surface was estimated by usi ng water vapor adsorption, thermogravimetric measurements, and X-ray p hotoelectron spectroscopy. Porous structure was analyzed on the basis of benzene vapor isotherms. Oxidation as well as heating in an argon a tmosphere changed markedly the concentration of the surface oxygen fun ctional groups without substantial changes in the porous structure of the carbons. Excess adsorption isotherms from ternary solutions benzen e (1) + diethyl ketone (2) + n-heptane (3) on chemically modified acti ve carbon samples were measured. Analysis of the excess adsorption iso therms of benzene from equimolar solutions diethyl ketone + n-heptane and analysis of the changes of this binary solvent composition indicat ed a close correlation between the concentration of functional groups on the carbon surface and adsorption of liquid components.