scholarly journals Investigation of trace metals in aquatic insects and bed sediments of the lower Clark Fork River, 1996-1997 /

1999 ◽  
Author(s):  
Don. Skaar ◽  
Kurt. Hill ◽  
◽  
◽  
Keyword(s):  
Trace Metals ◽  
Aquatic Insects ◽  
Bed Sediments ◽  
Clark Fork River

scholarly journals Using FlFFF and aTEM to determine trace metal–nanoparticle associations in riverbed sediment

2010 ◽  
Vol 7 (1) ◽  
pp. 82 ◽  
Author(s):  
K. L. Plathe ◽  
F. von der Kammer ◽  
M. Hassellöv ◽  
J. Moore ◽  
M. Murayama ◽  
...  
Keyword(s):  
Trace Metals ◽  
Toxic Metals ◽  
Inductively Coupled Plasma ◽  
Large Scale ◽  
Size Fraction ◽  
Metal Nanoparticle ◽  
Contaminated Sediment ◽  
Inductively Coupled ◽  
Clark Fork River ◽  
Nano Size

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.

Aquatic Insects as Bioindicators of Trace Element Contamination in Cobble-Bottom Rivers and Streams

1992 ◽  
Vol 49 (10) ◽  
pp. 2141-2154 ◽  
Author(s):  
Daniel J. Cain ◽  
Samuel N. Luoma ◽  
James L. Carter ◽  
Steven V. Fend
Keyword(s):  
Trace Element ◽  
Aquatic Insects ◽  
Single Species ◽  
Common Species ◽  
Whole Body ◽  
Individual Species ◽  
Bed Sediments ◽  
Element Concentrations ◽  
Mining Complex ◽  
Trace Element Contamination

Trace element bioaccumulation was studied in immature benthic insects from two contaminated river systems to develop these animals as bioindicators. In one river, Cu, Cd, Pb, and Zn were analysed in insects and in fine bed sediments over a 381-km reach downstream of a large copper mining complex. In the other river, As contamination from a gold mine was assessed in insects and bed sediments over a 40-km reach. All insect taxa collected in contaminated river reaches had elevated whole-body trace element concentrations. However, direct comparisons of contamination using a single, common species among stations were limited because few species were distributed throughout the study reaches. Comparisons of contamination at taxomic levels higher than species were complicated by element-specific differences in bioaccumulation among taxa. These differences appeared to be governed by biological and hydrogeochemical factors. The variation in element concentrations among species of the caddisfly Hydropsyche was slightly greater than within individual species. If this genus is representative of others, comparisons of contamination within genera may be a practical alternative for biomonitoring studies when single species are not available.

scholarly journals Controls on the Spatial Distribution of Trace Metal Concentrations along the Bedrock-Dominated South Fork New River, North Carolina

Geosciences ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 519
Author(s):  
Jerry R. Miller ◽  
Xaviera Watkins ◽  
Thomas O'Shea ◽  
Cynthia Atterholt
Keyword(s):  
North Carolina ◽  
Spatial Distribution ◽  
Trace Metals ◽  
Trace Metal ◽  
Coarse Grained ◽  
South Fork ◽  
Metal Concentrations ◽  
Bed Sediments ◽  
Fe And Mn ◽  
Toxic Trace Metals

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.

Diel Variation of Trace Metals in the Upper Clark Fork River, Montana

1996 ◽  
Vol 30 (6) ◽  
pp. 1953-1960 ◽  
Author(s):  
Christine M. Brick ◽  
Johnnie N. Moore
Keyword(s):  
Trace Metals ◽  
Diel Variation ◽  
Clark Fork River ◽  
Upper Clark Fork River

Temporal variations of trace metals in aquatic insects

1992 ◽  
Vol 27 (1) ◽  
pp. 13-27 ◽  
Author(s):  
LANDIS HARE ◽  
PETER G.C. CAMPBELL
Keyword(s):  
Trace Metals ◽  
Aquatic Insects ◽  
Temporal Variations
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