The oxygen sensitivity of organic macromolecule sorption by activated carbon: Effects of solution chemistry

The influence of solution chemistry (pH, ionic strength and calcium concentration) on the oxygen sensitivity of natural and synthetic dissolved organic macromolecule sorption by granular activated carbon was investigated. Sorption sensitivity to the presence of oxygen was found to decrease with decreasing pH, with increasing ionic strength and with increasing calcium concentration, The influence of oxygen on the extent of sorption by a basic GAC (pH(PZC) = 8.5) appears to be enhanced by increasing phenolic acidity and/or decreasing macromolecule size. The results suggest that open, flexible molecular configurations of organic macromolecules and the direct interactions of these substances with carbon surfaces are important factors with respect to the effects of oxygen on their sorption from aqueous phase. (C) 1998 Elsevier Science Ltd. All rights reserved.