In biological systems, vanadium is an essential component of some enzymes, particularly the vanadium nitrogenase used by some nitrogen-fixing microorganisms.
Vanadium was originally discovered by Andrйs Manuel del Rнo, a Spanish mineralogist in Mexico City, in 1803.
Vanadium has not been classified regarding carcinogenicity by the U.S. Environmental Protection Agency (EPA) (1991a).
Vanadium is never found as a free element in nature, but it occurs in about 65 different minerals.
Powdered metallic vanadium is a fire hazard, and unless known otherwise, all vanadium compounds should be considered highly toxic.
The toxicity of vanadium depends on its physicochemical state—particularly, its valence state and solubility.
Naturally occurring vanadium is composed of one stable isotope, 51V, and one radioactive isotope, 50V, with a half-life of 1.5Ч1017 years.
In 1831, Nils Gabriel Sefstrцm of Sweden rediscovered vanadium in a new oxide he found while working with some iron ores.
Administration of oxovanadium compounds has been shown to alleviate diabetes mellitus symptoms in certain animal models and humans.
Vanadium is a transition metal in period 4 of the periodic table, situated between titanium and chromium.
Industrially, most vanadium is used as an additive to improve steels.
Rather than proceed from pure vanadium metal, it is often sufficient to react the vanadium pentoxide with crude iron.
Soft and ductile, vanadium is resistant to corrosion by alkalis, sulfuric acid, and hydrochloric acid.
Commercially, metallic vanadium is usually recovered in sufficient quantities as a byproduct of other processes.
The National Institute for Occupational Safety and Health (NIOSH) has recommended that 35 mg/m3 of vanadium be considered immediately dangerous to life and health.
Metallic vanadium was isolated by Henry Enfield Roscoe in 1867, by reducing vanadium(III) chloride (VCl3) with hydrogen.
Vanadium is also needed by ascidians or sea squirts in vanadium chromagen proteins.
Reduction of the pentoxide with calcium gives pure vanadium.
The concentration of vanadium in their blood is more than one hundred times higher than that in the surrounding seawater.
Inhalation exposures to vanadium and vanadium compounds result primarily in adverse effects to the respiratory system (Sax 1984; ATSDR 1990).
Industrial production involves the heating of vanadium ore or residues from other processes with sodium chloride (NaCl) or sodium carbonate (Na2CO3) at about 850 °C, to give sodium vanadate (NaVO3).
Rats and chickens are also known to require vanadium in very small amounts and deficiencies result in reduced growth and impaired reproduction.
The name vanadium comes from Vanadis, a goddess in Scandinavian mythology, because the element has beautiful, multicolored chemical compounds.
Common oxidation states of vanadium include +2, +3, +4 and +5.
The water's vanadium pentoxide content ranges from about 80 to 130 ?g/liter.
Vanadium compounds are poorly absorbed through the gastrointestinal system.
An alternative term has been seacoal, probably because it came to many places in eastern England, including London, by sea.
Vanadium (chemical symbol V, atomic number 23) is a rare, silver-gray metal.
Vanadium-gallium tape is used in superconducting magnets, and vanadium pentoxide is a catalyst for manufacturing sulfuric acid and other products.