Effect of Tributary Inflows on the Distribution of Trace Metals in Fine-Grained Bed Sediments and Benthic Insects of the Clark Fork River, Montana

1997 ◽  
Vol 31 (3) ◽  
pp. 750-758 ◽  
Author(s):  
Ellen V. Axtmann ◽  
Daniel J. Cain ◽  
Samuel N. Luoma



2010 ◽  
Vol 7 (1) ◽  
pp. 82 ◽  
Author(s):  
K. L. Plathe ◽  
F. von der Kammer ◽  
M. Hassellöv ◽  
J. Moore ◽  
M. Murayama ◽  
...  

Environmental context. Determining associations between trace metals and nanoparticles in contaminated systems is important in order to make decisions regarding remediation. This study analysed contaminated sediment from the Clark Fork River Superfund Site and discovered that in the <1-μm fraction the trace metals were almost exclusively associated with nanoparticulate Fe and Ti oxides. This information is relevant because nanoparticles are often more reactive and show altered properties compared with their bulk equivalents, therefore affecting metal toxicity and bioavailability. Abstract. Analytical transmission electron microscopy (aTEM) and flow field flow fractionation (FlFFF) coupled to multi-angle laser light scattering (MALLS) and high-resolution inductively coupled plasma mass spectroscopy (HR-ICPMS) were utilised to elucidate relationships between trace metals and nanoparticles in contaminated sediment. Samples were obtained from the Clark Fork River (Montana, USA), where a large-scale dam removal project has released reservoir sediment contaminated with toxic trace metals (namely Pb, Zn, Cu and As) which had accumulated from a century of mining activities upstream. An aqueous extraction method was used to recover nanoparticles from the sediment for examination; FlFFF results indicate that the toxic metals are held in the nano-size fraction of the sediment and their peak shapes and size distributions correlate best with those for Fe and Ti. TEM data confirms this on a single nanoparticle scale; the toxic metals were found almost exclusively associated with nano-size oxide minerals, most commonly brookite, goethite and lepidocrocite.



1998 ◽  
Vol 38 (11) ◽  
pp. 169-175 ◽  
Author(s):  
D. Bogner ◽  
M. Juracic ◽  
N. Odžak ◽  
A. Baric

The aim of the present work was to study the past and present contamination of the Kaštela bay using chemical analysis of selected trace metals (Cd, Pb, Zn, Cu, Cr, Mn and Ni) in fine grained sediment cores. Sediment samples were taken at three locations with silty sediments. The highest concentrations of Cd, Pb, Cu and Zn and the lowest concentration of Ni were found in the east, the most contaminated part of the Bay. The decrease of Cd, Pb, Cu and Zn concentrations with increased depth, indicates their anthropogenic origin. Homogeneous distribution of Cr, Mn and Ni in the sediment cores indicates their terrigenous origin. The correlation of Zn, Cu and Ni concentration with the organic matter content was determined.









CATENA ◽  
1989 ◽  
Vol 16 (2) ◽  
pp. 135-151 ◽  
Author(s):  
Mark G. Macklin ◽  
Richard B. Dowsett
Keyword(s):  


Geosciences ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 519
Author(s):  
Jerry R. Miller ◽  
Xaviera Watkins ◽  
Thomas O'Shea ◽  
Cynthia Atterholt

In marked contrast to alluvial rivers, few studies have examined the physical and geochemical controls on the spatial distribution of toxic trace metals along bedrock channels. This study examined the factors controlling the geographical pattern of selected trace metal (Cu, Cr, and Zn) concentrations along the bedrock-dominated channel of the South Fork New River (SFNR). The SFNR is located in the Blue Ridge Physiographic Province of North Carolina, and is representative of many rivers in mountainous terrains that are often subjected to the influx of toxic trace metals from historic and contemporary mining operations. The topography of the SFNR’s channel bed is highly variable and can be subdivided into pool and shallow bedrock reaches. The latter contained localized cascades characterized by topographically higher bedrock ribs that are separated by topographic lows, both of which are oriented oblique to flow. Accumulations of bed sediments are predominantly associated with the traverse bedrock ribs that generate high hydraulic roughness. Except for a few localized zones of enrichment, sediment-associated trace metal concentrations tended to vary within a narrow range of background values over the 36 km study reach. Elevated trace metal concentrations were closely linked to zones of high Fe and Mn concentrations, and were associated with pools located within or immediately downstream of bedrock cascades. The elevated concentrations of the metals appear to be derived from the erosion of lithologic units within the cascades that contain sulfidic layers or zones of mafic mineral enrichment, and which are known to occur in the underlying bedrock. Once eroded, these minerals and/or rock fragments were deposited within low-velocity zones created by the transverse ribs or within downstream pools. The enrichment of trace metals downstream of the cascades may also be due to the formation of Fe and Mn oxyhydroxides as turbulent flows aerate river waters as they traverse the cascades. Chemically reactive fine-grained (<63 µm) sediments had a relatively limited influence on the downstream variations in metal concentrations, presumably because the channel bed sediments are composed primarily of sand-sized and larger particles. Although a principal component analysis (PCA) suggested that reach-scale variations in channel and valley morphology may have partly influenced downstream variations in trace metal concentrations, the geographical patterns were primarily controlled by local geological and geomorphic factors associated with the bedrock cascades. The design of future sampling programs along such coarse-grained, bedrock rivers should consider the significance of these local controls on trace metal storage to effectively characterize and interpret downstream patterns in metal concentrations.



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