Adsorption of organic macromolecules by granular activated carbon .2. Influence of dissolved oxygen

The influence of dissolved oxygen (DO) on the uptake of natural and synthetic macromolecular dissolved organic materials (DOMs) from aqueous solutions by granular activated carbon (GAG) was investigated. The sorption behaviors of six of the nine DOMs tested were enhanced by the presence of DO; these included polymaleic acid, peat humic acid, Leonardite humic acid, Suwannee River fulvic acid, and Laurentian fulvic and humic acids. The sorptions of Aldrich and soil humic acids and polystyrene sulfonate were not sensitive to the presence or absence of DO. Sensitivity of sorption to DO generally increased with decreasing molecular size, polydispersity, and aromaticity and with increasing acidity for the five natural DOMs. Oxygen-sensitive sorption of the low molecular weight fractions of peat humic acid, a slightly oxygen-sensitive DOM, was noticeably greater than that of the whole material, Sorption of the low molecular weight fractions of Aldrich humic acid, an oxygen-insensitive DOM, did not show any particular sensitivity to oxygen.