Donald J. O'Connor

The effect of concentration of adsorbing solids on the partition coefficient

Abstract The results of a number of laboratory studies are presented to demonstrate an inverse relationship between concentration of adsorbing solids and partition coefficient. Various functional forms which define the relation are developed and correlated with the data. A power-law dependence of partition coefficient on concentration of solids is shown. The significance of this relationship in assessing the fate of hydrophobic pollutants in natural water systems is discussed.

A food chain model of cadmium in western lake Erie

Abstract The simple food chain model illustrated here could prove useful in large scale planning applications provided additional data are collected on the various trophic levels. The model demonstrates the increase in concentration of potentially toxic substances, such as cadmium, as one proceeds up the food chain. The food chain model also illustrates how interactive modeling between complex non-linear and linear compartment model can be accomplished. The problem of verification and data availability are highlighted by the model: estimates of transfer rates and biomass of different trophic levels must be on hand. This model therefore is an example of a modeling structure that is still in an early stage of development; hence the reliance on linear kinetics rather than possibly more realistic non-linear mechanisms. Nevertheless, the spatial-trophic level structure of the model indicates the general behavior of a toxicant such as cadmium when released into the water environment.