Chromium oxidation by manganese (hydr)oxides in a California aquifer
2010 (English)In: Applied Geochemistry, ISSN 0883-2927, E-ISSN 1872-9134, Vol. 25, no 3, 377-381 p.Article in journal (Refereed) Published
There are increasing concerns with elevated levels of Cr(VI) in the environment because It IS a Strong oxidant. corrosive, and carcinogenic The concerns extend to the presence of Cr(VI) in many aquifers in California and elsewhere. where relatively high levels have been attributed to both industrial pollution and natural processes The authors have, therefore, determined if natural redox processes contribute to the presence of high Cr(VI) concentrations (6-36 mu g L-1) in all aquifer in central California relative to non-detectable concentrations (<0.1 mu g L-1) in all adjacent aquifer Specifically, the distribution and the redox speciation of dissolved (<0.45 mu m) Cr have been compared with those of particulate Mn and Fe oxy-hydioxides in sediments, using X-ray absorption spectroscopy at the Mn and Fe L-edges The analyses show a correlation between the presence of dissolved Cr(VI) and Mn (hydr)oxide minerals, which are the only common, naturally occurring minerals known to oxidize Cr(Ill) in laboratory experiments This covariance substantiates the results of those experiments and previous field studies that indicate natural oxidation mechanisms might account for the relatively high levels of Cr(VI) in the study site. as well as for elevated concentrations in other aquifers with similar biogeochemical conditions.
Place, publisher, year, edition, pages
2010. Vol. 25, no 3, 377-381 p.
HEXAVALENT CHROMIUM; SPECTROSCOPY; WATER; FIELD
Research subject Environmental Chemistry
IdentifiersURN: urn:nbn:se:su:diva-50051DOI: 10.1016/j.apgeochem.2009.12.004ISI: 000275580200005OAI: oai:DiVA.org:su-50051DiVA: diva2:382220
authorCount :4 2010-12-302010-12-212010-12-30Bibliographically approved