Thermodynamic of the adsorption of benzene from water on activated carbon

For better understanding the characteristics of adsorption of benzene on activated carbone, Analysis the physical and chemical characteristics of two kinds of carbon, the micro-surface area of coal carbon is 320 m2/g, which is far less than that of woody carbon that is 563 m2/g. The chemical groups on the surface of coal carbon is abundant than that on woody carbon. The qualitative analysis of the adsorption of water molecule on two kinds of carbon is conducted by Dubinin and Sperpinsky equation (DS), the results show that, the coal carbon is prone to adsorb water molecule while the woody carbon is tend to adsorb benzene; Using four isotherm equations (Langmuir, Freundlich, Sips, Toth) to simulate the experimental data, the results show that the relativity coefficient (R2) of the Toth equation is more close to 1, and it best fits the adsorption of benzene from water; compare the parameters of thermodynamic of the adsorption of benzene on two kinds of carbons, the results indicate that differences of Gibbs free energy (-ΔG0), enthalpy (ΔH0) and entropy (ΔS0) of woody carbon are larger than that of coal carbon, which indicate that the woody carbon is more adaptable to adsorb benzene from water.