Effect of temperature on adsorption of phenol on microporous activated FAS-type carbons

Phenol adsorption from aqueous solutions is studied on activated FAS-type carbons. It is shown that the limiting adsorption value grows at an increase in the temperature from 293 to 318 K. The anomalous character of the temperature dependence of adsorption is related to competition between two simultaneous processes, i.e., activated and physical adsorption. The obtained adsorption isotherms are well described by the Dubinin-Radushkevich (DR) equation with an exponent of 2. It is shown that, in the case of phenol adsorption on FAS microporous carbons of different porosity, temperature invariance of the characteristic curve of the DR model is observed. Parameters of the DR equation are determined for the studied systems. Isosteric adsorption heat is calculated based on the temperature dependence of adsorption.