Effect of selected parameters on the adsorption of phenol on activated charcoal

The adsorption of phenol on activated carbon was studied under varying conditions of time, pH and degassing temperature. Equilibrium adsorption was established within 4 h. The pH was found to have a pronounced effect on adsorption. The change in adsorption due to pH level might be caused by ionization of the phenol into cationic and anionic species and by the respective positive and negative charged surfaces of carbon, which it acquired at low and high pH levels. An increase in degassing temperature was also found to have a significant effect on the adsorption of phenol. This was thought to be due to the comparatively non‐polar surface and large surface area of the carbon samples degassed at high temperatures. Degassing at high temperatures causes decomposition and the evolution of polar surface functional groups, leaving the carbon surface relatively non‐polar, where upon the non‐polar phenol adsorb to a comparatively large extent. Freundlich’s and Langmuir’s equations were successfully applied to the adsorption isotherms.