Environmental chemistry of chromium
- 1 October 1989
- journal article
- Published by Elsevier BV in Science of The Total Environment
- Vol. 86 (1-2), 15-23
- https://doi.org/10.1016/0048-9697(89)90189-7
Abstract
The processes that control the environmental chemistry of chromium include redox transformation, precipitation/dissolution, and adsorption/desorption reactions. Commonly occurring reductants, such as ferrous iron and organic material, can transform Cr(VI) to Cr(III), but manganese oxides are the only inorganic oxidants found in the environment that cause the rapid oxidation of Cr(III) to Cr(VI). In the trivalent state, chromium readily forms compounds such as Cr(OH)3 and (Cr,Fe)(OH)3. These solids show amphoteric solubility behavior, with hydroxo complexes being the dominant aqueous species of Cr(III). The relatively low solubilities of Cr(OH)3 and (Cr,Fe)(OH)3 limit Cr(III) concentrations to less than the drinking water limit over much of the pH range of environmental interest. In the hexavalent state, the formation of the Ba(S,Cr)O4 solid solution controls the dissolved chromium concentrations in environments that contain BaSO4. In the absence of solubility-controlling Cr(VI) solids, Cr(VI) concentrations in acidic to slightly alkaline conditions are expected to be limited by adsorption. Iron oxides are the most important adsorbents for aqueous Cr(VI) species in most soil environments. Although these processes are complex and interrelated, each must be considered to predict the aqueous concentrations, mobility, and toxicity of chromium in the environment.Keywords
This publication has 17 references indexed in Scilit:
- Adsorption of Chromate by Subsurface Soil HorizonsSoil Science Society of America Journal, 1989
- Chromate removal from aqueous wastes by reduction with ferrous ionEnvironmental Science & Technology, 1988
- Kinetics of chromium(III) oxidation to chromium(VI) by reaction with manganese dioxideEnvironmental Science & Technology, 1987
- Chromate adsorption on amorphous iron oxyhydroxide in the presence of major groundwater ionsEnvironmental Science & Technology, 1987
- Adsorption and Desorption of Hexavalent Chromium in an Alluvial Aquifer Near Telluride, ColoradoJournal of Environmental Quality, 1985
- Behavior of Chromium in Soils: VII. Adsorption and Reduction of Hexavalent FormsJournal of Environmental Quality, 1983
- Reduction of chromium(VI) by bacterially produced hydrogen sulphide in a marine environmentWater Research, 1981
- Chemical speciation of chromium in sea water: Part 2. Effects of Manganese Oxides and Reducible Organic Materials on the Redox Processes of ChromiumAnalytica Chimica Acta, 1981
- Behavior of Chromium in Soils: III. OxidationJournal of Environmental Quality, 1979
- Behavior of Chromium in Soils: II. Hexavalent FormsJournal of Environmental Quality, 1976