Factors affecting reduction of selenate to elemental selenium in agricultural drainage water by Enterobacter taylorae.
Microbial reduction of selenate [Se(VI)] to elemental selenium [Se(0)] is a useful technique for removing Se from agricultural drainage water. A series of batch experiments were conducted in the laboratory to determine the effects of yeast extract (50-1000 mg/L), salinity (EC, 5-75 dS/m), and NO(3)(-) (5-100 mg/L) on the removal of Se(VI) (2000 microg/L) from drainage water by Enterobacter taylorae. Results showed that relatively high amounts of yeast extract (500 mg/L) were needed for E. taylorae to effectively reduce Se(VI) to Se(0). During a 7-day experiment, approximately 95% of added Se(VI) was reduced to Se(0) in the low-salinity drainage water (5 dS/m) with NO(3)(-) values of 5-50 mg/L. In the high-salinity drainage water (50-75 dS/m), reduction of Se(VI) to Se(0) was limited. E. taylorae was also capable of reducing Se(VI) to Se(0) in the San Joaquin Valley drainage water, with a reduction of the added Se(VI) to Se(0) (73.8%) and Se(-II) (20%). This study suggests that E. taylorae may be used to treat Se(VI)-contaminated drainage water in the field.
Zhang
Yiqiang
Y
Department of Environmental Sciences, University of California, Riverside, California 92521, USA.
Zahir
Zahir A
ZA
Frankenberger
William T
WT
D000383:Agriculture; D004754:Enterobacter / Q000378:metabolism*; D010084:Oxidation-Reduction; D064586:Selenic Acid; D012643:Selenium / Q000378:metabolism*; D018036:Selenium Compounds / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000378:metabolism*
D018036:Selenium Compounds; D014874:Water Pollutants, Chemical; D012643:Selenium; D064586:Selenic Acid