Trace metal

About: Trace metal is a research topic. Over the lifetime, 5125 publications have been published within this topic receiving 181046 citations.

A 50-yr Record of Pollution by Nutrients, Trace Metals, and Organic Chemicals in the St Lawrence River

Abstract: The deposition chronology of algal pigments, organic C, N, P, trace metals, and organic contaminants (PCB congeners, DDD, DDE, Mirex, hexachlorobenzene) is described for two sites in fluvial lakes (St. Francis and St. Louis) of the St. Lawrence River. Pigment concentrations rapidly decrease in the top 10 cm due to degradation, but show a broad secondary peak consistent with higher primary productivity between 1960 and 1975. In Lake St. Francis, deposition of organic C, N, and P peaked between 1950 and 1975. In both lakes, trace metal concentrations reached maximum values between 1960 and 1970 and decreased considerably between 1970 and 1980. At both sites, surficial trace metal concentrations are approaching (within a factor of 3) those observed in preindustrial sediments except Cd, which is still 5–6 times higher. Concentrations of Cr, Cu, Ni, and Zn are inversely related (p < 0.05) to river discharge whereas those of Pb are positively related to discharge. Concentrations of organic contaminants have dec...

Trace metal dynamics in floodplain soils of the river elbe: a review.

Abstract: This paper reviews trace metal dynamics in floodplain soils using the Elbe floodplains in Germany as an example of extraordinary importance because of the pollution level of its sediments and soils. Trace metal dynamics are determined by processes of retention and release, which are influenced by a number of soil properties including pH value, redox potential, organic matter, type and amount of clay minerals, iron-, manganese- and aluminum-oxides. Today floodplains act as important sinks for contaminants but under changing hydraulic and geochemical conditions they may also act as sources for pollutants. In floodplains such changes may be extremes in flooding or dry periods that particularly lead to altered redox potentials and that in turn influence the pH value, the mineralization of organic matter as well as the charge of the pedogenic oxides. Such reactions may affect the bioavailability of trace metals in soils and it can be clearly seen that the bioavailability of metals is an important factor for estimating trace metal remobilization in floodplain soils. However as bioavailability is not a constant factor, there is still a lack of quantification of metal mobilization particularly on the basis of changing geochemical conditions. Moreover, mobile amounts of metals in the soil solution do not indicate to which extent remobilized metals will be transported to water bodies or plants and therefore potentially have toxicological effects. Consequently, floodplain areas still need to be taken into consideration when studying the role and behavior of sediments and soils for transporting pollutants within river systems, particularly concerning the Water Framework Directive.