Colloidal and particulate silver in river and estuarine waters of Texas


1997 Mar


Wen LS
Santschi PH
Gill GA
Paternostro CL
Lehman RD

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Concentration and phase speciation of Ag in selected Texas rivers and in the Trinity River estuary were measured in order to establish the major factors that control its fate in the aquatic environment from source to sink. Concentrations of Ag in the filter-passing fractions in Texas rivers ranged from <0.01 to 62 ng/L. In the Trinity River estuary (Galveston Bay), they ranged from 0.4 to 6.4 ng/L and showed a non-conservative estuarine mixing behavior. An internal source of filter-passing ( less than or equal to 0.45 mu m) and colloidal (1 kDa-0.45 mu m) Ag was observed in the upper Trinity Bay. Silver, associated with colloidal macromolecular organic matter, which was isolated using cross-flow ultrafiltration techniques, amounted to 15-70% of the filtered ( less than or equal to 0.45 mu m) Ag concentration, decreasing with increasing salinity. Such a trend was similar to that of dissolved and colloidal organic carbon. Estuarine distributions of colloidal Ag were also broadly similar to those of suspended particulate matter. The ratio of colloidal Ag to filter-passing Ag was similar to the ratio of colloidal organic carbon to total dissolved organic carbon, suggesting not only that Ag is complexed by organic macromolecules but also that functional groups with high affinity for Ag were evenly distributed over the different molecular weight fractions




aquatic environment, BAY, colloids, Environment, Estuaries, GALVESTON, Galveston Bay, ORGANIC CARBON, ORGANIC MATTER, P 2000 FRESHWATER POLLUTION, Rivers, SALINITY, silver, SW 3020 Sources and fate of pollution, Texas, trace metals, TRINITY RIVER, TX, USA,Texas,Trinity R., WATER, water sampling