51 research outputs found

    Metal Bioavailability in the Sava River Water

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    Metals present one of the major contamination problems for freshwater systems, such as the Sava River, due to their high toxicity, persistence, and tendency to accumulate in sediment and living organisms. The comprehensive assessment of the metal bioavailability in the Sava River encompassed the analyses of dissolved and DGT-labile metal species of nine metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in the river water, as well as the evaluation of the accumulation of five metals (Cd, Cu, Fe, Mn, and Zn) in three organs (liver, gills, and gastrointestinal tissue) of the bioindicator organism, fish species European chub (Squalius cephalus L.).This survey was conducted mainly during the year 2006, in two sampling campaigns, in April/May and September, as periods representative for chub spawning and post-spawning. Additionally, metal concentrations were determined in the intestinal parasites acanthocephalans, which are known for their high affinity for metal accumulation. Metallothionein concentrations were also determined in three chub organs, as a commonly applied biomarker of metal exposure. Based on the metal concentrations in the river water, the Sava River was defined as weakly contaminated and mainly comparable with unpolluted rivers, which enabled the analyses of physiological variability of metal and metallothionein concentrations in the chub organs, as well as the establishment of their constitutive levels

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    Lathyrus jepsonii E. GreeneDelta tule pea,  Jepson's peaca. 15 mi. NE of Springville at Coffee Creek C ampground in Sequoia Nat'l Forestgrowing in Oak Woodland in decomposed granite soil on N-facing slope in shade3500 feetperennial herb ca. 1.5 ft. high with purple fls

    Assessment of water quality and toxicity of polluted Rivers Fez and Sebou in the region of Fez (Morocco)

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    Water quality assessment in the region of Fez based on the physicochemical and ecotoxicological investigations is presented. The results indicate that sites located close to the most urbanized and industrialized areas are severely impaired. The major water quality problems are: low dissolved oxygen (DO), high turbidity, organic matter and ammonia contents, severe chromium and copper pollution and high acute and chronic toxicity. This results in the loss of the aquatic life which is still flourishing in the Fez River upstream from the Fez Medina. Remote sites downstream show signs of physicochemical recovery. However, even there, bioassays showed significant acute and chronic toxicity. Well water in the region of Fez has moderately poor water quality with nitrate and metal enrichments. Use of water for drinking or for agriculture from the rivers or from some well without treatment may expose the population to health risk. </p

    Partitioning of chromium (VI) and chromium (III) between dissolved and colloidal forms in a stream and reservoir contaminated with tannery waste water

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    Environmental fate of chromium rejected from tannery wastewater to the Dunajec River (southern Poland) was investigated using separation with tangential flow filtration followed by measurements with Cathodic Adsorptive Stripping Voltammetry (CAdSV) and ICP-MS. Virtually all Cr(VI) was found in the dissolved fraction (<<1 kDa). Thus form was present at low concentrations. Cr(III) was rapidly transferred from dissolved and low molecular weight colloidal fractions to particles and high molecular weight colloids and thus scavenged from the water column of the Czorsztyn Reservoir to the sediments. The possibility of Cr remobilization via oxidation of Cr(III) in the presence of freshly precipitated Mn-oxides in water or at the water-sediment interface needs further investigation.
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