Abstract

Activated carbons are widely used as an adsorbent in numerous applications and especially in the phenolics treatment field, due to its excellent adsorption capacity and great flexibility. However, molecular oxygen has been found to be a significant factor in the adsorption of phenolics onto activated carbon (Grant and King 1990; Nakhla et al. 1994; Tessmer et al. 1997). Molecular oxygen was found to be able to promote a significant increase in the adsorptive capacity of activated carbon at the cost of reduction in the recovery of adsorbents. Studies have attributed this phenomenon to the oligomerization of phenolics (oxidative coupling) on the surface of activated carbon (Vidic et al. 1993). Analyzing the solvent extracted products by GC–MS has shown the presence of oligomerized phenols, which are essentially irreversibly bound to carbon surface (Vidic et al. 1997). As a consequence, the regeneration efficiency of activated carbon after the oligomerization of phenolic compounds is low. The cost of adsorbents has been the major concern in activated carbon adsorption usage. In this chapter, the theory as well as factors for controlling oligomerization is outlined. The description of development of novel activated carbon for oligomerization control is also the main subject of this contribution.