Difference between revisions of "Nickel"
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{{Definition|title= nickel | {{Definition|title= nickel | ||
| − | |definition=Nickel is the heavy metal, with chemical symbol Ni and atomic number 28. Nickel is silvery-white with a slight golden tinge that takes a high polish. It is one of only four elements that are magnetic at or near room temperature and is hard and ductile. It is an chemical element, and as such very stable. Very small amounts of nickel have been shown to be essential for normal growth and reproduction in some species of animals. <ref name = wiki>[http://en.wikipedia.org/wiki/Nickel wikipedia August 18 2009]</ref> <ref>[http://glossary.eea.europa.eu/terminology/concept_html?term=nickel%20and%20its%20compounds glossary.eea.europa.eu August 18 2009]</ref>}} | + | |definition=Nickel is the heavy metal, with chemical symbol Ni and atomic number 28. Nickel is silvery-white with a slight golden tinge that takes a high polish. It is one of only four elements that are magnetic at or near room temperature and is hard and ductile. It is an chemical element, and as such very stable. Very small amounts of nickel have been shown to be essential for normal growth and reproduction in some species of animals. <ref name = wiki>[http://en.wikipedia.org/wiki/Nickel http://www.wikipedia.org/ August 18 2009]</ref> <ref>[http://glossary.eea.europa.eu/terminology/concept_html?term=nickel%20and%20its%20compounds glossary.eea.europa.eu August 18 2009]</ref>}} |
== Notes == | == Notes == | ||
Revision as of 11:35, 18 August 2009
Definition of nickel:
Nickel is the heavy metal, with chemical symbol Ni and atomic number 28. Nickel is silvery-white with a slight golden tinge that takes a high polish. It is one of only four elements that are magnetic at or near room temperature and is hard and ductile. It is an chemical element, and as such very stable. Very small amounts of nickel have been shown to be essential for normal growth and reproduction in some species of animals. [1] [2]
This is the common definition for nickel, other definitions can be discussed in the article
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Notes
Nickel is a significant contaminant in the sediments of industrialised areas and serious attempts have been made to reduce nickel inputs to the sea. It has been used in steel, batteries and is also used as a catalyst. Fossil fuels are usually rich in nickel and combustion of oil and coal results in a significant contribution to atmospheric deposition, but the mayor input of nickel to the sea is through rivers. Most of the nickel is particulate and is therefore present in the soils of estuaries.[3]
No organisms have been found to contain very high concentrations of nickel. Molluscs commonly bioaccumulate metals, however there is no evidence that they or other species bioaccumulate or biomagnify nickel.
Nickel is regarded as only moderately toxic, although it can be toxic for some algae species at concentrations above 600 µg/l. Some crustacean species might die at concentrations above 150 µg/l although others tolerate much higher concentrations up to 42 mg/l. Estuarine fishes die when exposed to concentrations above 38 mg/l.
Concentrations in the ocean are usually around 0.2 µg/l, those in the open North Sea around 0,3 µg/l but near the Dutch concentrations of 1 µg/l can be measured. A few studies have suggested that soil concentrations of nickel of around 30 mg/kg might have resulted in a loss of species diversity and caused lethal effects to the larvae of oysters. However, it couldn't be ruled out that these effects might also have been caused by other pollutants. [4]
Environmental standards and legislation
Included in the water framework list of priority substances
See also
Nickel on the ED North Database
References
- ↑ http://www.wikipedia.org/ August 18 2009
- ↑ glossary.eea.europa.eu August 18 2009
- ↑ Clark, R,B., 1999. Marine pollution. Oxford University press, Fourth edition, pp 161
- ↑ Clark, R,B., 1999. Marine pollution. Oxford University press, Fourth edition, pp 161
