Abstract
The dissimilatory iron reducing bacterium Shewanella oneidensis MR-1 (MR-1) exhibited a strong sodium butyl xanthate (SBX) biodegradation capability in the presence of Cr(VI) under aerobic conditions. In addition, 89.27% of SBX at a concentration of 30 mg/L was degraded within 48 h in the presence of 10 mg/L Cr(VI). Temperature and pH significantly affected SBX biodegradation, and MR-1 exhibited an enhanced biodegradation ability at a pH of 6°C and 30°C. Biodegradation kinetics of SBX in the presence of Cr(VI) and anions (NO3−, SO42−, or CO32−) followed the first-order exponential decay kinetics model. The inhibition effect was different for the different types and concentrations of coexisting anions. NO3− exhibited negligible inhibitory effects on SBX removal, whereas SO42− and CO32− had a potential inhibitory effect on SBX removal. When the coexisting anion concentrations were 10 and 30 mg/L, the order of inhibiting factor (IF) of the anions on SBX removal was
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$${ \rm{ \;I}}{{ \rm{F}}_{SO_4^{2 - }}}$$
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>
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$${ \rm{I}}{{ \rm{F}}_{CO_3^{2 - }}} > { \rm{ \;I}}{{ \rm{F}}_{NO_3^ - }}$$
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, whereas when the anion concentrations increased to 60 and 100 mg/L, the order of IF was
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$${ \rm{I}}{{ \rm{F}}_{CO_3^{2 - }}}$$
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>
\documentclass{aastex}\usepackage{amsbsy}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{bm}\usepackage{mathrsfs}\usepackage{pifont}\usepackage{stmaryrd}\usepackage{textcomp}\usepackage{portland, xspace}\usepackage{amsmath, amsxtra}\usepackage{upgreek}\pagestyle{empty}\DeclareMathSizes{10}{9}{7}{6}\begin{document}
$${ \rm{I}}{{ \rm{F}}_{SO_4^{2 - }}}$$
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>
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$${ \rm{I}}{{ \rm{F}}_{NO_3^ - }}$$
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. Results obtained from this study showed that MR-1 could be used for the treatment of flotation wastewater.
