The effect of molecular oxygen on the activated carbon adsorption of natural organic matter in Ohio river water

Recently published data show that the adsorptive capacity of granular activated carbon for phenols increases significantly in the presence of molecular oxygen (Vidic, Suidan, Traegner and Nakhla, 1990). In this study, the effect of molecular oxygen on the adsorptive capacity of activated carbon for the natural organic matter present in Ohio River water was investigated. This source of natural organic matter was selected because it is a natural surface water and represents Cincinnatiʹs main drinking water supply. Isotherm studies using pulverized activated carbon were conducted during the first week of each month of the year 1992. Adsorption isotherms were conducted on water from two stages of treatment (raw water directly pumped from the Ohio River and settled water from the California Drinking Water Treatment Plant, Cincinnati, Ohio). Investigations were conducted in the presence and absence of molecular oxygen. An appreciable increase in the adsorptive capacity of activated carbon for natural organic matter was noticed when molecular oxygen was present in the test environment. The adsorption isotherms were further described by fractionating the unknown matrix into a non adsorbable fraction and four fictive components of different adsorbabilities.