Hexavalent chromium removal in two-stage bioreactor system

Journal Article · Wed Nov 01 04:00:00 EST 1995 · Journal of Environmental Engineering

DOI:https://doi.org/10.1061/(ASCE)0733-9372(1995)121:11(798)· OSTI ID:162996

Shen, H; Wang, Y T ^[1]

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1. Univ. of Kentucky, Lexington, KY (United States). Dept. of Civil Engineering

A two-stage bioreactor system was used to reduce Cr(VI). Escherichia coli ATCC 33456 cells were aerobically grown in a first-stage chemostat, and then pumped to a second-stage plug-flow reactor where anaerobic Cr(VI) reduction occurred. Experimental results demonstrated that near complete removal of Cr(VI) was achieved in the plug-flow reactor under appropriate operating conditions. The removal efficiency in the plug-flow reactor was significantly affected by the influent Cr(VI) concentration, Cr(VI) loading rate, liquid detention time, and a consumed Cr(VI) reduction capacity factor. The consumed Cr(VI) reduction capacity factor was directly related to the toxicity effect of Cr(VI) on cells. To illustrate the influence of the consumed reduction capacity factor on Cr(VI) reduction in the plug-flow reactor, a mathematical model was developed by incorporating Cr(VI) reduction kinetics into the mass balance relationship of C(VI) for a plug-flow reactor. Analyses of Cr(VI) concentration profiles along the plug-flow reactor using both model simulations and experimental data indicated that the rate of Cr(VI) reduction decreased with the depletion of the reduction capacity of cells ad Cr(VI) reduction ceased after the reduction capacity was exhausted.

• Sponsoring Organization: USDOE
• OSTI ID: 162996
• Journal Information: Journal of Environmental Engineering, Journal Name: Journal of Environmental Engineering Journal Issue: 11 Vol. 121; ISSN 0733-9372; ISSN JOEEDU
• Country of Publication: United States
• Language: English

Related Subjects

56 BIOLOGY AND MEDICINE
APPLIED STUDIES
AEROBIC CONDITIONS
BIODEGRADATION
BIOREACTORS
CHROMIUM
ESCHERICHIA COLI
GROWTH
MATHEMATICAL MODELS
PERFORMANCE
TOXICITY