Modelling Cr(VI) reduction by pure bacterial cultures

Wang, Yi‐Tin; Shen, H. Z.

doi:10.1016/s0043-1354(96)00309-0

Cited by 89 publications

(75 citation statements)

References 14 publications

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“…The results obtained in this study are at variance with that observed earlier with individual strains of Bacillus and Streptomyces Shen, 1995, 1997). In the case of Streptomyces griseus, an initial Cr(VI) concentration of 50 mg/L required over 50 h for complete reduction while with the bacterial consortium used in this study, the same was complete within 24 h (Wang and Shen, 1997). This is possibly due to the fact that mixed consortium would provide adequate tolerance to metal ions than individual strains, similar to that observed in the case of sulphate-reducing bacteria (Cheung and Gu, 2003).…”

Section: Initial Concentration Of Chromium(vi)supporting

confidence: 65%

“…This variation could be explained by tracing back the conditions from which the bacteria were sourced. It is possible that the consortium B, sourced from a tannery soil did not contain specific Pseudomonas species like Pseudomonas fluorescens LB 300 or Pseudomonas ambigua G-1, which are reported to reduce Cr(VI) (Wang and Shen, 1997). It is further possible that the external environment from which the bacteria was isolated had several other compounds or ions, which inhibited the growth of Cr(VI)-reducing bacteria.…”

Section: Studies On the Effect Of Various Factors Affecting Chromium(mentioning

confidence: 99%

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Biological removal of carcinogenic chromium(VI) using mixed Pseudomonas strains

Aravindhan

Sreeram

Rao

et al. 2007

J. Gen. Appl. Microbiol.

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The contamination of soil and wastewaters with Cr(VI) is a major problem. It has been suggested that microbial methods for Cr(VI) reduction are better than chemical methods, as they do not add other ions or toxic chemicals to the environment. In this study an aerobic reduction of Cr(VI) to Cr(III) by employing mixed Pseudomonas cultures isolated from a marshy land has been reported. The role of chromium concentration, temperature, pH and additives on the microbial reduction of Cr(VI) has been investigated. NADH was found to enhance the rate of reduction of Cr(VI). Complete reduction of chromium(VI) has been possible even at chromium(VI) concentrations of 300 ppm. Ions like SO 4 2؊ and poly-phenols inhibited the metabolic activity relating to Cr(VI) reduction. Under optimal conditions 100 mg/L of Cr(VI) was completely reduced within 180 min.

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Section: Initial Concentration Of Chromium(vi)supporting

confidence: 65%

Section: Studies On the Effect Of Various Factors Affecting Chromium(mentioning

confidence: 99%

Biological removal of carcinogenic chromium(VI) using mixed Pseudomonas strains

Aravindhan

Sreeram

Rao

et al. 2007

J. Gen. Appl. Microbiol.

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“…The ability of some microorganisms to reduce highly soluble and toxic Cr(VI) to less toxic and soluble Cr(III) has been reported (Lovley and Phillips 1994;Wang and Xiao 1995). E. coli cells reduced Cr(VI) under both aerobic and anaerobic conditions as described in the earlier study by Wang and Shen (1997). They demonstrated Cr(VI) reduction by Cr(VI)-reducing organism, E. coli ATCC 33456 in the batch tests.…”

Section: Introductionmentioning

confidence: 75%

“…The concentration of Cr(III) was measured using an ICS 1500 Ion Chromatograph system (Dionex Corporation, Sunny-vale, CA) that was equipped with an HPIC-CS5 column and quantified at 520 nm using a UV-Vis detector (Wang and Shen 1997;Chirwa and Wang 2000). All tests were duplicated, and the relative experimental error of Cr(VI) analysis was estimated to be within ±5 %.…”

Section: Methodsmentioning

confidence: 99%

“…All tests were duplicated, and the relative experimental error of Cr(VI) analysis was estimated to be within ±5 %. The optical density of the E. coli cells suspension was determined by turbidimetric measurement in a UV-Vis spectrophotometer (Shimadzu, model UV-1700) at 610 nm and correlated to dry cell weight (Wang and Shen 1997;Bae et al 2000). …”

Section: Methodsmentioning

confidence: 99%

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Modeling chromium(VI) reduction by Escherichia coli 33456 using ceramic pearl as a supporting medium

Lin

2013

Int. J. Environ. Sci. Technol.

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A mathematical model was developed to describe the reduction of Cr(VI) by Escherichia coli (E. coli) 33456 in a fixed biofilm reactor. A laboratoryscale column reactor was conducted to verify the model system. The batch kinetic tests were independently conducted to determine the biokinetic parameters used in the model simulation. With the assumed values of initial biofilm thickness (L f0 ), the mathematical model simulated well the experimental results for Cr(VI) effluent concentration, effluent concentration of suspended E. coli cells, and Cr(III) production. The concentration of suspended E. coli cells reached up to 1.2 mg cell/L while the thickness of attached E. coli cells was estimated to be 32.6 lm at a steady-state condition. At the steady state, the removal efficiency of Cr(VI) was about 92 % and the effluent concentration of Cr(III) was approximately 1.6 mg/L. The approaches presented in this study can be employed for the design of a pilot-scale or full-scale fixed biofilm reactor to treat Cr(VI)-containing wastewater.

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Reduction kinetics of Fe(III), Co(III), U(VI), Cr(VI), and Tc(VII) in cultures of dissimilatory metal‐reducing bacteria

Liu

Gorby

Zachara

et al. 2002

Biotech & Bioengineering

310

199

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The reduction kinetics of Fe(III)citrate, Fe(III)NTA, Co(III)EDTA-, U(VI)O(2) (2+), Cr(VI)O(4) (2-), and Tc(VII)O(4) (-) were studied in cultures of dissimilatory metal reducing bacteria (DMRB): Shewanella alga strain BrY, Shewanella putrefaciens strain CN32, Shewanella oneidensis strain MR-1, and Geobacter metallireducens strain GS-15. Reduction rates were metal specific with the following rate trend: Fe(III)citrate > or = Fe(III)NTA > Co(III)EDTA- >> UO(2)(2+) > CrO(4)(2-) > TcO(4)(-), except for CrO(4) (2-) when H(2) was used as electron donor. The metal reduction rates were also electron donor dependent with faster rates observed for H(2) than lactate- for all Shewanella species despite higher initial lactate (10 mM) than H2 (0.48 mM). The bioreduction of CrO(4) (2-) was anomalously slower compared to the other metals with H(2) as an electron donor relative to lactate and reduction ceased before all the CrO(4)(2-) had been reduced. Transmission electron microscopic (TEM) and energy-dispersive spectroscopic (EDS) analyses performed on selected solids at experiment termination found precipitates of reduced U and Tc in association with the outer cell membrane and in the periplasm of the bacteria. The kinetic rates of metal reduction were correlated with the precipitation of reduced metal phases and their causal relationship discussed. The experimental rate data were well described by a Monod kinetic expression with respect to the electron acceptor for all metals except CrO(4)(2-), for which the Monod model had to be modified to account for incomplete reduction. However, the Monod models became statistically over-parameterized, resulting in large uncertainties of their parameters. A first-order approximation to the Monod model also effectively described the experimental results, but the rate coefficients exhibited far less uncertainty. The more precise rate coefficients of the first-order model provided a better means than the Monod parameters, to quantitatively compare the reduction rates between metals, electron donors, and DMRB species.

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Modelling Cr(VI) reduction by pure bacterial cultures

Cited by 89 publications

References 14 publications

Biological removal of carcinogenic chromium(VI) using mixed Pseudomonas strains

Biological removal of carcinogenic chromium(VI) using mixed Pseudomonas strains

Modeling chromium(VI) reduction by Escherichia coli 33456 using ceramic pearl as a supporting medium

Reduction kinetics of Fe(III), Co(III), U(VI), Cr(VI), and Tc(VII) in cultures of dissimilatory metal‐reducing bacteria

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