Speciation of some metals in river surface water, rain and snow, and the interactions of these metals with selected soil matrices

Various metal species in river water, rain and snow were characterized by size and molecular weight using techniques such as filtration, ultrafiltration and characterization of each size fraction by its chemical reactivity on Chelex cation-exchange resin using both column and batch techniques. The wet-deposition of trace metal species through runoff into the Rideau river, Ottawa, Ont., was estimated by determining rain water metal species concentrations before and after contact with selected soils in the laboratory. Plainfield sandy soil and Green belt soil from Ottawa were used to model the transformation of metal species from rain water to soil. Metals such as aluminium, copper, lead and nickel, at low metal:ligand ratios (present in uncontaminated freshwaters), formed relatively inert complexes with humic compounds as a result of the strong humate metal ion binding sites. Most metal species in rain water were transformed from simple, small and labile species to larger non-labile species (metals bound to humic and/or colloidal materials) after equilibration of rain water and soils. There are 51 references.