title: Factors controlling the regional distribution of vanadium in groundwater.
abstract: Although the ingestion of vanadium (V) in drinking water may have possible adverse health effects, there have been relatively few studies of V in groundwater. Given the importance of groundwater as a source of drinking water in many areas of the world, this study examines the potential sources and geochemical processes that control the distribution of V in groundwater on a regional scale. Potential sources of V to groundwater include dissolution of V rich rocks, and waste streams from industrial processes. Geochemical processes such as adsorption/desorption, precipitation/dissolution, and chemical transformations control V concentrations in groundwater. Based on thermodynamic data and laboratory studies, V concentrations are expected to be highest in samples collected from oxic and alkaline groundwater. However, the extent to which thermodynamic data and laboratory results apply to the actual distribution of V in groundwater is not well understood. More than 8400 groundwater samples collected in California were used in this study. Of these samples, high (> or =50 microg/L) and moderate (25 to 49 microg/L) V concentrations were most frequently detected in regions where both source rock and favorable geochemical conditions occurred. The distribution of V concentrations in groundwater samples suggests that significant sources of V are mafic and andesitic rock. Anthropogenic activities do not appear to be a significant contributor of V to groundwater in this study. High V concentrations in groundwater samples analyzed in this study were almost always associated with oxic and alkaline groundwater conditions, which is consistent with predictions based on thermodynamic data.
authors.affiliation: U.S. Geological Survey, California Water Science Center, San Diego, CA 92101, USA. mtwright@usgs.gov
authors.forename: Michael T
authors.initials: MT
authors.lastname: Wright
authors.forename: Kenneth
authors.initials: K
authors.lastname: Belitz
mesh_terms: D000327:Adsorption; D002140:California; D011232:Chemical Precipitation; D005618:Fresh Water / Q000032:analysis / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D010084:Oxidation-Reduction; D014639:Vanadium / Q000032:analysis / Q000737:chemistry*; D014877:Water Pollution, Chemical / Q000032:analysis
chemical_list: D014639:Vanadium