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Environmental factors and modeling in microbial chromium (VI) reduction
Author(s) -
Chen Jin M.,
Hao Oliver J.
Publication year - 1996
Publication title -
water environment research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.356
H-Index - 73
eISSN - 1554-7531
pISSN - 1061-4303
DOI - 10.2175/106143096x128586
Subject(s) - chemistry , chemostat , chromium , sulfate , nitrate , nuclear chemistry , carbon fibers , biomass (ecology) , environmental chemistry , inorganic chemistry , bacteria , organic chemistry , ecology , genetics , materials science , composite number , composite material , biology
A Cr(VI)‐reducing culture was enriched from an anaerobic chemostat fed with synthetic media containing acetate and Cr(VI). The enriched culture was used for a series of batch tests to investigate several environmental factors affecting microbial Cr(VI) reduction. Under carbon‐limiting conditions, the extent of Cr(VI) reduction proportionally depended on the carbon concentration and no reduction of Cr(VI) was observed in the absence of acetate. Cr(VI) reduction was also dependent upon the initial biomass level and the type of organic compounds. The developed model predicted Cr(VI) reduction well at different Cr(VI) concentrations.
Sulfate at 120 mg SO 4 2− /L or nitrate at 150 mg N/L slightly inhibited Cr(VI) reduction. Reduction of nitrate but not sulfate was observed along with Cr(VI) reduction. Cr(VI) was not reduced by the aerobically growing culture, and it was found that oxygen inhibitory effects on Cr(VI) reduction were reversible. The optimum pH and temperature for Cr(VI) reduction were found to be 7.3 and 32°C, respectively. In addition, Cr(VI) reduction was sensitive to the metal ions that may coexist with Cr(VI) in industrial wastes containing Cr(VI).