Vanadium cycle
{{Short description|Exchange of vanadium between continental crust and seawater}}
The global vanadium cycle is controlled by physical and chemical processes that drive the exchange of vanadium between its two main reservoirs: the upper continental crust and the ocean.{{Cite journal|last1=Schlesinger|first1=William H.|last2=Klein|first2=Emily M.|last3=Vengosh|first3=Avner|date=2017|title=Global biogeochemical cycle of vanadium|journal=Proceedings of the National Academy of Sciences|language=en|volume=114|issue=52|pages=E11092–E11100|doi=10.1073/pnas.1715500114|issn=0027-8424|pmid=29229856|pmc=5748214 |doi-access=free}} Anthropogenic processes such as coal and petroleum production release vanadium to the atmosphere.
Sources
{{biogeochemical cycle sidebar|other}}
= Natural sources =
Vanadium is a trace metal that is relatively abundant in the Earth (~100 part per million in the upper crust). Vanadium is mobilized from minerals through weathering and transported to the ocean. Vanadium can enter the atmosphere through wind erosion and volcanic emissions and will remain there until it is removed by precipitation.
= Anthropogenic sources =
Human activity has increased the amount of vanadium emissions to the atmosphere.{{Cite journal|last=Hope|first=Bruce K.|date=1997|title=An assessment of the global impact of anthropogenic vanadium|url=https://doi.org/10.1023/A:1005761904149|journal=Biogeochemistry|language=en|volume=37|issue=1|pages=1–13|doi=10.1023/A:1005761904149|s2cid=93183351 |issn=1573-515X|url-access=subscription}} Vanadium is abundant in fossil fuels because it is incorporated in porphyrins during organic matter degradation.{{Citation|last1=Zhao|first1=Xu|title=Porphyrins in Heavy Petroleums: A Review|date=2016|url=https://doi.org/10.1007/430_2015_189|work=Structure and Modeling of Complex Petroleum Mixtures|pages=39–70|editor-last=Xu|editor-first=Chunming|series=Structure and Bonding|place=Cham|publisher=Springer International Publishing|language=en|doi=10.1007/430_2015_189|isbn=978-3-319-32321-3|access-date=|last2=Xu|first2=Chunming|last3=Shi|first3=Quan|editor2-last=Shi|editor2-first=Quan|url-access=subscription}} Coal and petroleum factory pollution release significant vanadium to the atmosphere. Vanadium is also mined and using for industrial purposes including for steel reinforcement, electronics, and batteries.
Sink
Vanadium is removed from the ocean by burial marine sediments and incorporation into iron oxides at hydrothermal vents.{{Cite journal|last1=Trefry|first1=John H.|last2=Metz|first2=Simone|date=1989|title=Role of hydrothermal precipitates in the geochemical cycling of vanadium|url=https://www.nature.com/articles/342531a0|journal=Nature|language=en|volume=342|issue=6249|pages=531–533|doi=10.1038/342531a0|bibcode=1989Natur.342..531T |s2cid=4351410 |issn=1476-4687|url-access=subscription}}
Biological processes
Biological processes play a relatively minor role in the global vanadium cycle. Vanadium bromoperoxidase is present in some marine bacteria and algae.{{Cite journal|last=Butler|first=Alison|date=1998|title=Vanadium haloperoxidases|url=https://www.sciencedirect.com/science/article/pii/S1367593198800707|journal=Current Opinion in Chemical Biology|language=en|volume=2|issue=2|pages=279–285|doi=10.1016/S1367-5931(98)80070-7|pmid=9667930 |issn=1367-5931|url-access=subscription}} Vanadium can also takes the place of molybdenum in alternative nitrogenases.{{Cite journal|last=Eady|first=Robert R.|date=1996|title=Structure−Function Relationships of Alternative Nitrogenases|url=https://doi.org/10.1021/cr950057h|journal=Chemical Reviews|volume=96|issue=7|pages=3013–3030|doi=10.1021/cr950057h|pmid=11848850 |issn=0009-2665|url-access=subscription}}