摘要：

Humic materials have been isolated from sea, river and lake waters by an adsorption technique, and the stability constants of their complexes with Ca, Mg, Mn, Co, Ni, Cu, Zn, Cd and Hg have been determined at pH 8.0 using a gel filtration chromatographic technique. In general, the order of increasing strength of binding of the metals followed the Irving-Williams series. The stability constant data have been used in conjunction with the HALTAFALL program of Ingri et al. (1967) to compute speciation models for freshwaters and seawater which take into account metal-humic interactions. In freshwater more than 90% of the copper and mercury was found to be complexed by humic materials. However, <11% of the other metals was bound in this way. In seawater, >99% of the humic material is complexed by calcium and magnesium because of their relatively high concentrations; metal chelation is only appreciable for copper (~10%). The pattern of trace element speciation with inorganic ligands in seawater differs somewhat from that computed by previous workers largely because of the use of more up-to-date stability constant data. Finally, an attempt has been made to compute the changes in metal speciation which would occur when river water becomes diluted with seawater as in an estuary.

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