Organic matter can strongly affect metal ion binding to soil and sediment.
In fact, production of a major form of organic matter low-molecular weight organic ligands is the principal mechanism by which plants and microbes acquire metal ions, so that the chemistry of biogenic organic matter is the key to understanding mechanisms of bioavailability for bioremediation purposes. Thus, the complex interaction between metal ions, biogenic ligands, and humic substances must be understood to engineer the proper organisms and conditions for bioremediation of metal ion contamination. Understanding the chemistry imposed by these complex mixtures is crucial, and therefore is a major focus of our effort. Concomitant with the size changes were dramatic changes in major peaks, revealed through EEM fluorescence. We are currently pursuing the identity of these peaks.