Collections > Master's Papers > Gillings School of Public Health > Testing of a Multicomponent Model of Adsorption and Biodegradation of Natural Organic Matter on Activated Carbon

Adsorption and biodegradation studies were performed to characterize the components present in natural organic material (NOM) obtained from Lake Drummond, in southeastern Virginia. NOM adsorbability was characterized by dividing it into fictive components, using the Ideal Adsorbed Solution Theory (IAST) to find the Freundlich parameters and initial concentration of each. This was done for ozonated and ozonated-biostabilized NOM. The isotherm results, along with the results of the biokinetic experiment, were used to determine the components of the model NOM solution. A batch biokinetic study was performed to determine the biokinetic parameters for the ozonated NOM solution. A first-order model was fit to the experimental data, giving a first-order rate constant, yield coefficient, and coefficient of microbial decay for the biodegradable fraction of the NOM. A multicomponent model developed by Pedit (1988) was tested using the experimentally determined adsorption and biodegradation parameters. The model failed to predict the breakthrough of total organic carbon (TOC) and the resulting total inorganic carbon (TIC) production when the biodegradable fraction of NOM was assumed to be 55 percent, as determined using a continuous flow GAC reactor which had apparently reached an exhaustion of adsorption capacity. The model results were improved when the biodegradable fraction was assumed to be 15 percent, as obtained from the batch biokinetic experiment. This suggests that slow adsorption, in addition to biodegradation, may have been responsible for long term TOC removal in the continuous flow GAC reactor.