Metal in river waters

Example Multivariate cross-correlation for the computation of transport rates of dissolved metals in river water... 

Speciation of Heavy Metals in River Water Investigated by Chemometric Methods... 

Reus U, Markeit B, Hoffmeister C, Spott D, Guhr H (1993) Determination of trace metals in river water and suspended solids by TXRF spectroscopy A methodical study on analytical performance and sample homgeneity. Fresenius J Anal Chem 347 430-435 Sanchez HJ. (2001) Detection limit calculations for the total reflection techniques of X-ray fluorescence analysis. Spectrochimica Acta 56 2027-2036... 

Reus, U., Markert, B., Holfmeister, C., Spott, D., Guhr, H., 1993. Determination of trace metals in river water and suspended soils by TXRF spectrometry. Fresenius Z. Anal. Chem. 347, 430-435. 

Wilson, A. L. Concentration of Trace Metals in River Waters A Review, ... 

E. Munoz, S. Palmero, M.A. Garcfa-Garcfa, A continuous flow system design for simultaneous determination of heavy metals in river water samples, Talanta 57 (2002) 985—992. 

The paper describes the different chemical sensors and mathematical methods applied and presents the review of electronic tongue application for quantitative analysis (heavy metals and other impurities in river water, uranium in former mines, metal impurities in exhaust gases, ets) and for classification and taste determination of some beverages (coffee, bear, juice, wines), vegetable oil, milk, etc. [1]. 

The corrosion testing of metals in natural waters is most usually conducted in field or service tests since the conditions of flow are important and often rate-determining. Testing will be concerned with mains water (potable water), river-water and sea-water or combinations of these as in estaurine conditions. Test specimens of various geometries will be used, e.g. in the... 

Most cation exchange occurs in estuaries and the coastal ocean due to the large difference in cation concentrations between river and seawater. As riverborne clay minerals enter seawater, exchangeable potassium and calcium are displaced by sodium and magnesium because the Na /K and Mg /Ca ratios are higher in seawater than in river water. Trace metals are similarly displaced. 

The chemical or physical form of trace metals in water is often of interest. The form in which a specific element is present will often influence is toxic effects. For instance the chemical state of chromium affects its toxicity i.e., Cr+6 is more carcino genic than Cr+3, Kopp (48) has described the various forms in which metals may he present. The categories include dissolved metals, suspended metals, total metals, extractable metals and organometallics. In addition, Kopp describes sample preparation requirements for each category. Gihhs (20) has also studied metal species in river water. It should be obvious that the desired analytical result has to he considered beforehand. For example, if dissolved metal concentrations were desired and normal acid preservation performed, suspended metals could possibly be solubilized to a large extent. Both Hamilton (25) and Robertson (81) have shown vast differences between acidified and non-acidified samples. Many other publications have dealt with this subject (16, 37, 80, 30). 

Kopp JF, Kroner RC. 1970. Trace metals in waters of the United States. A five year summary of trace metals in rivers and lakes of the United States (Oct. 1, 1962- Sept. 30, 1967). Cincinnati, OH US Department of the Interior, Federal Water Pollution Control Administration, Division of Pollution Surveillance. 

Lu JY, Chakrabarti CL, Back MH, et al. 1996. Speciation of some metals in river surface water, rain and snow, and the interactions of these metals with selected soil matrices. J Anal Atom Spectrom 11 1189-1201. 

Nowadays modern instrumental analytical methods enable largely precise and accurate determination of total concentrations of heavy metals in environmental compartments. The assessment of toxicologically relevant levels in river water on the basis of total concentrations is connected with the following ... 

The concentrations of heavy metals both in river water and in river sediment are strongly changed by deposition-remobilization processes. The deterministic modeling of the transition between both environmental compartments is severely limited by the complex chemical, physical, and biochemical processes. 

In rivers and streams heavy metals are distributed between the water, colloidal material, suspended matter, and the sedimented phases. The assessment of the mechanisms of deposition and remobilization of heavy metals into and from the sediment is one task for research on the behavior of metals in river systems [IRGOLIC and MARTELL, 1985]. It was hitherto, usual to calculate enrichment factors, for instance the geoaccumulation index for sediments [MULLER, 1979 1981], to compare the properties of elements. Distribution coefficients of the metal in water and in sediment fractions were calculated for some rivers to find general aspects of the enrichment behavior of metals [FOR-STNER and MULLER, 1974]. In-situ analyses or laboratory experiments with natural material in combination with speciation techniques are another means of investigation [LANDNER, 1987 CALMANO et al., 1992], Such experiments manifest univariate dependencies for the metals and other components, for instance between different metals and nitrilotriacetic acid [FORSTNER and SALOMONS, 1991], but the interactions in natural systems are often more complex. 

The strong dissolution effects on heavy metals of increasing phosphate concentrations in river water (Fig. 8-19) indicate the strong remobilization effects which result from complex formation. This tendency for complex formation with triphosphates is also described in the literature [GMELIN, 1965]. Increasing the concentration of phosphate in water from 0.38 to 0.68 mg L 1 increases the iron concentration by 648 pg L 1 in water in contact with sediment in which the iron concentration is 16220 mg kg ... 

Chakrabarti, C.L., Lu, Y., Gregoire, D.C., Back, M.H. and Schroeder, W.H. (1994) Kinetic studies of metal speciation using Che lex cation exchange resin application to cadmium, copper, and lead speciation in river water and snow. Environ. Sci. Technol, 28, 1957-1967. 

Djane, N.-K., Ndung u, K., Malcus, F., Johansson, G. and Mathiasson, L. (1997) Supported liquid membrane enrichment using an organophosphorus extractant for analytical trace metal determinations in river waters. Fresenius J. Anal. Chem., 358, 822-827. 

Hoffman, M.R., Yost, E.C., Eisenreich, S.J. and Maier, WJ. (1981) Characterization of soluble and colloidal-phase metal complexes in river water by ultrafiltration. A mass-balance approach. Environ. Sci. Technol, 15, 655-661. 

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