Rivers metal concentrations

Fig. 15-7 Relationship between dissolved and total heavy metal concentrations in several rivers. Cross-hatched bands represent range of values from the Ruhr (Imhoff et ah, 1980) W and F represent winter and fall values at a selected station in the Mississippi (Eisenreich et ah, 1980) Triangles represent values from the Rhine river (Davis, 1984).

Behra R, Landwehrjohann R, Vogel K, Wagner B, Sigg L (2002) Copper and Zinc content of periphyton from two rivers as function of dissolved metal concentration. Aquat Sci 64 300... 

Fitchko J, Hutchinson TC. 1975. A comparative study of heavy metal concentrations in river mouth sediments around the Great Lakes. J Great Lakes Res 1 46-78. 

Chemical analysis of the Meza River and its tributaries revealed significant heavy metal pollution of the upper Meza River sediments with lead, zinc, and some molybdenum, cadmium and arsenic enrichments. The trend of Cd and As is similar to trend of Pb and Zn, which is in agreement with the fact that Cd and As are associated with Pb and Zn in ore minerals (Strucl, 1984 Fux Gosar, 2007). In the lower Meza valley, these heavy metal concentrations decreased somewhat. 

Distribution coefficients based on adsorption equilibria are independent of the total concentrations of metal ions and suspended solids, as long as the metal concentrations are small compared with the concentration of surface groups. Examples of the Kd obtained from calculations for model surfaces are presented in Fig. 11.1. A strong pH dependence of these Kd values is observed. The pH range of natural lake and river waters (7 - 8.5) is in a favorable range for the adsorption of metal ions on hydrous oxides. 

Table 11.2 gives some representative examples of dissolved trace metal concentrations in rivers, especially in large impolluted rivers. 

The data show that rivers contain remarkably low concentrations (in some cases concentrations are as low as 10 11 M) of dissolved metal ions. (Many data that have been reported in the literature have been based on total particulate and dissolved concentrations furthermore, analytical procedures have often not been able to discriminate against contamination during sampling and sample processing.) The metal concentrations in rivers are a consequence of... 

Table 11.2 Examples of Dissolved Trace Metal Concentrations in Rivers... 

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). 

As the acidity of a river or lake increases, it can trigger a secondary effect. Metals that are normally tied up as compounds in the ground become soluble and enter the water. In such cases, the combined effects of low pH and increased metal concentration are even more harmful to aquatic organisms than the sum of the two effects taken separately. For example, many fish are able to survive in water with a pH of less than 5.0. But if the water contains a small amount of iron, as little as 1 ppm, fish will begin to die at a pH as high as 5.5. 

By coupling flow field-flow fractionation (flow FFF) to ICP-MS it is possible to investigate trace metals bound to various size fractions of colloidal and particulate materials.55 This technique is employed for environmental applications,55-57 for example to study trace metals associated with sediments. FFF-ICP-MS is an ideal technique for obtaining information on particle size distribution and depth profiles in sediment cores in addition to the metal concentrations (e.g., of Cu, Fe, Mn, Pb, Sr, Ti and Zn with core depths ranging from 0-40 cm).55 Contaminated river sediments at various depths have been investigated by a combination of selective extraction and FFF-ICP-MS as described by Siripinyanond et al,55... 

Figure 6.13 shows the distribution of heavy metal concentrations along the AYRS constructed by means of a computer experiment. We see that there are three maxima of heavy metal concentrations located at distances from Lake Baikal of 200 km, 1,200 km, and 2,000 km. This is the result of the distribution of pollution sources along the river system. The AYRS neutralizes pollutants over a distance of... 

Trocine RP, Trefry JH. 1996. Metal concentrations in sediment, water and clams from the Indian River Lagoon, Florida. Mar Pollut Bull 32 754-759. 

The cross-correlation function of the concentrations of any compound, which are observable in a stream and which scatter like heavy metals, is a possible means of measuring transport rates in flowing systems. The maximum of the cross-correlation function indicates the time which is needed for transporting these compounds. For this purpose, the time series of heavy metal concentrations (Cd, Cr, Cu, Fe, and Zn) at two sampling points in the river 4.5 km apart taken at exactly the same time were cross-correlated (Tab. 6-2) [EINAX et al., 1994],... 

Tab. 6-2. Scheme of cross-correlated time series of metal concentrations in a river...

The mean values of the heavy metal concentrations in the river Saale are demonstrated in Tab. 8-5. 

Hickey CW, Roper DS, Buckland S. 1995a. Metal concentrations of resident and transplanted freshwater mussels Hyridella menziesi (Unionacea Hyriidae) and sediments in the Waikato River, New Zealand. Sci Tot Environ 175 163-177. 

The edible parts of several species of fish and other marine organisms inhabiting the Calcasieu River/Lake, in Southwest Louisiana, were determined for As, Cd, Cr, Cu, Pb, Hg, Ag, and Zn [20], Concentrations of all elements measured in both intra and interspecies showed no significant variation with sample location. Differences in metal concentrations were related to organism mobility and not to site-specific variations in metal loadings. Different species of finfish contained only trace amounts (in p,g kg-1) of Ag (<0.01-0.3), As (<0.1-0.3), Cd (0.02-0.08), and Pb (<0.2-0.5). 

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