Desorption of phenol from activated carbon by hot water regeneration. Desorption isotherms

Adsorption of phenol from aqueous solutions at high temperatures on activated carbon was studied. The adsorption capacities were determined by the semicontinuous desorption experiments carried out in a fixed bed adsorber, which was operated in liquid-full mode at a pressure of 25 bar and at temperatures up to 190 degrees C. It was found that in the range of phenol concentrations from 0.005 to 30 g/L the five-parameter Redlich-Petersen adsorption model is equivalent to the six-parameter Fritz-Schlunder adsorption model when describing liquid-solid adsorption on the Filtrasorb (F-400) activated carbon. By hot water regeneration, 95% recovery of initial adsorption capacity of activated carbon was obtained. It is also demonstrated that the proposed experimental method for determination of adsorption capacities at high temperatures can be used as an alternative to the traditional method by taking breakthrough curves.