Biogeochemistry of selenium. A review
Selenium levels and speciation in environmental compartments and the dynamics of global Se cycling continue to be a subject of intense interest largely because Se is both an essential element and a toxicant at elevated levels. While Se containing amino acids and proteins are known to be critical for normal metabolic functions in many life forms, selenosis, poisoning due to chronic excessive Se intake, has been associated with neurological impairment. This paper reviews the current understanding of the biogeochemistry of selenium in the natural environment. The factors that affect Se speciation in natural environments are chemical, physical, and biological processes. Several inorganic species of Se (−2, 0, +4, and +6) and organic species (monomethylated and dimethylated) have been reported in aquatic systems. Both HSeO3 − and SeO3 2− would be present in natural waters. Under mild oxidizing conditions, HSeO3 − and SeO3 2− are the major species, while HSe− would be the dominant species at pH greater than 4 and strong reducing conditions. The biogeochemistry of selenium is discussed in terms of variation of speciation with pH and redox conditions, sorption on solid surfaces, role of reducing species under oxic/anoxic conditions, and interaction with natural organic matter.
KeywordsSelenium Speciation Abiotic reduction Sorption Organic matter
V.K. Sharma and R. Zboril acknowledge the support by the Operational Program Research and Development for Innovations–European Regional Development Fund (CZ.1.05/2.1.00/03.0058).
- Alloway BJ (1990) Heavy metals in soils. Blackie, LondonGoogle Scholar
- Beckett R, Ranville J (2006) Chapter 17: Natural organic matter. In: Newcombe G, Dixon D (eds) Interface science in drinking water treatment, vol 10, pp 299–315Google Scholar
- Chinn R, Barrett S (1999) Occurrence of amino acids in drinking water sources. Book of Abstracts, ACS Nat Meeting 217Google Scholar
- Huang X, Liu X, Luo Q, Liu J, Shen J (2011) Artificial selenoenzymes: Designed and redesigned. Chem Soc Rev 40:1171–1184Google Scholar
- Ihnat M (1992) Chapter 16 selenium. Techniques and instrumentation in analytical chemistry. In: Stoeppler M (ed) Hazardous Metals in the Environment, vol 12, pp 475–515Google Scholar
- Kunenkov EV, Kononikhin AS, Perminova IV, Hertkorn N, Gaspar A, Schmitt-Kopplin P, Popov IA, Garmash AV, Nikolaev EN (2009) Total mass difference statistics algorithm: a new approach to identification of high-mass building blocks in electrospray ionization fourier transform ion cyclotron mass spectrometry data of natural organic matter. Anal Chem 81:10106–10115CrossRefGoogle Scholar
- Lakin HW (1972) Selenium accumulation in soils and its absorption by plants and animals. Spec Pap Geol Soc Am 140:45–53Google Scholar
- Schellenger AEP, Larese-Casanova P (2013) Oxygen isotope indicators of selenate reaction with Fe(II) and Fe(III) hydroxides. Environ Sci Technol 47:6254–6262Google Scholar
- Scheuhammer A, Braune B, Chan HM, Frouin H, Krey A, Letcher R, Loseto L, Noël M, Ostertag S, Ross P, Wayland M (2014) Recent progress on our understanding of the biological effects of mercury in fish and wildlife in the Canadian Arctic. Sci Total Environ. doi: 10.1016/j.scitotenv.2014.05.142
- Schmidt R, Tantoyotai P, Fakra SC, Marcus MA, Yang SI, Pickering IJ, Bañuelos GS, Hristova KR, Freeman JL (2013) Selenium biotransformations in an engineered aquatic ecosystem for bioremediation of agricultural wastewater via brine shrimp production. Environ Sci Technol 47:5057–5065CrossRefGoogle Scholar