| Abstract
| - A cost-effective remediation method is needed to remove selenium (Se) from Se-contaminated water.In this study, a selenate [Se(VI)]-reducing bacterium, Citrobacter braakii, that is capable of usingmolasses as a carbon source to reduce Se(VI) from natural river and drainage waters was isolated.During an 8-day experiment, 87−97% of the added Se(VI) in New River water and White River water,California, was reduced to elemental Se [Se(0)] or transformed to organic Se. In highly saline drainagewater, removal of Se(VI) by C. braakii was limited, with 20% Se(VI) removal in a 7-day experiment.Addition of zero-valent iron (ZVI) into these waters along with C. braakii inoculation significantlyenhanced the removal of Se(VI) and reduced the formation of organic Se. This study suggests thatthe combination of a bacterial treatment using inexpensive molasses and ZVI can effectively removeSe from natural river water and agricultural drainage waters. Keywords: Selenium speciation; selenate reduction; zero-valent iron; molasses; Citrobacter braakii;selenium-contaminated water
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