Interpretation of Trace Metal Complexation by Aquatic Organic Matter

Abstract

Although a classification of aquatic organic matter is difficult, an examination of recent literature reviews (Williams (1975), Reuter and Perdue (1977), Buffle (1984)) indicates that the major groups of organic ligands are polysaccharides, proteins and peptides, “pedogenic” (soil derived) refractory organic matter (PROM) and “aquogenic” (formed in situ in the water body) refractory organic matter (AROM). Altogether, the last two groups form the so-called water fulvic and humic acids which represent a large proportion (~ 70–80%) of the organic matter in natural waters. The characteristics of PROM resemble those of soil fulvic acids (SFA: extracted from soil; Schnitzer (1978)), but differ markedly from those of AROM and of humic and fulvic fractions of sediments (Buffle (1984)). The complexation data reported in the literature concern mostly SFA and the fulvic fractions of PROM and AROM.