Characterization of a phenol degrading mixed population by enzyme assay

Kibret, Mulugeta; Somitsch, Walter; Robra, Karl‐Heinz

doi:10.1016/s0043-1354(99)00248-1

Cited by 78 publications

(49 citation statements)

References 16 publications

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“…Addition of n-butannol (hydroxyl radical scavenger) decreased the degradation rate of phenol, which demonstrates that hydroxyl radicals were mainly responsible for the removal of phenol. We demonstrated that phenol may be degraded by hydroxyl radicals decomposed by hydrogen peroxide on the surface of Fe 78 Si 9 B 13 and illustrated the reaction mechanism for this process. This amorphous alloy exhibited high stability in recycling experiments and showed excellent reuse performance even after continuous operations of 8 cycles.…”

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confidence: 82%

“…Batch experiments for solutions containing phenol concentrations ranging from 50 to 2000 mg/L were investigated under the above conditions and the same excellent degradation rate was obtained. The Fe 78 Si 9 B 13 showed better catalytic activity than iron powder and Fe 2+ . Addition of n-butannol (hydroxyl radical scavenger) decreased the degradation rate of phenol, which demonstrates that hydroxyl radicals were mainly responsible for the removal of phenol.…”

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confidence: 93%

“…The influences of main operating parameters such as reaction temperature, catalyst amount, hydrogen peroxide dosage and initial pH of solution on phenol degradation rate were investigated. The maximum mineralization of phenol was achieved at 60°C, 6 g/L Fe 78 Si 9 B 13 , 0.31 mol/L hydrogen peroxide, with an initial pH of 2.5. More than 99% of phenol was completely removed under the optimum conditions within 10 min for a solution containing 1000 mg/L of phenol.…”

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confidence: 97%

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Catalytic oxidation of phenol in wastewater — A new application of the amorphous Fe78Si9B13 alloy

Wang

Bian

2012

Chin. Sci. Bull.

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The amorphous Fe 78 Si 9 B 13 alloy was used as a heterogeneous Fenton catalyst in the process of phenol degradation. The influences of main operating parameters such as reaction temperature, catalyst amount, hydrogen peroxide dosage and initial pH of solution on phenol degradation rate were investigated. The maximum mineralization of phenol was achieved at 60°C, 6 g/L Fe 78 Si 9 B 13 , 0.31 mol/L hydrogen peroxide, with an initial pH of 2.5. More than 99% of phenol was completely removed under the optimum conditions within 10 min for a solution containing 1000 mg/L of phenol. Batch experiments for solutions containing phenol concentrations ranging from 50 to 2000 mg/L were investigated under the above conditions and the same excellent degradation rate was obtained. The Fe 78 Si 9 B 13 showed better catalytic activity than iron powder and Fe 2+. Addition of n-butannol (hydroxyl radical scavenger) decreased the degradation rate of phenol, which demonstrates that hydroxyl radicals were mainly responsible for the removal of phenol. We demonstrated that phenol may be degraded by hydroxyl radicals decomposed by hydrogen peroxide on the surface of Fe 78 Si 9 B 13 and illustrated the reaction mechanism for this process. This amorphous alloy exhibited high stability in recycling experiments and showed excellent reuse performance even after continuous operations of 8 cycles.phenol degradation, iron-based amorphous alloy, heterogeneous catalyst, Fenton reaction Citation:Wang P, Bian X F, Li Y X. Catalytic oxidation of phenol in wastewater-A new application of the amorphous Fe 78 Si 9 B 13 alloy.

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confidence: 82%

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confidence: 93%

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confidence: 97%

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Catalytic oxidation of phenol in wastewater — A new application of the amorphous Fe78Si9B13 alloy

Wang

Bian

2012

Chin. Sci. Bull.

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“…Wastewaters contaminated by phenol endanger fish life even at a relatively low concentration, e.g., 5 to 25 mg liter Ϫ1 (2,14). For drinking water, the phenol concentration should be no higher than 1 g liter Ϫ1 (31).…”

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confidence: 99%

“…Then a 100-l cell suspension was transfused into the glass tubes (16 by 160 mm) containing 2 ml sterile saline water. The obtained suspension was irradiated using a He-Ne laser with an 800-m optical fiber using an optical laser wavelength of 632.8 nm in the dark (14,29). The optical fiber was fixed with a delivery arm that permitted precise positioning of the fiber tip 80 mm above the cell suspension.…”

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confidence: 99%

Mutation of Candida tropicalis by Irradiation with a He-Ne Laser To Increase Its Ability To Degrade Phenol

Jiang

Wen

Jia

et al. 2007

Appl Environ Microbiol

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Candida tropicalis isolated from acclimated activated sludge was used in this study. Cell suspensions with 5 ؋ 10 7 cells ml ؊1 were irradiated by using a He-Ne laser. After mutagenesis, the irradiated cell suspension was diluted and plated on yeast extract-peptone-dextrose (YEPD) medium. Plates with approximately 20 individual colonies were selected, and all individual colonies were harvested for phenol biodegradation. The phenol biodegradation stabilities for 70 phenol biodegradation-positive mutants, mutant strains CTM 1 to 70, ranked according to their original phenol biodegradation potentials, were tested continuously during transfers. Finally, mutant strain CTM 2, which degraded 2,600 mg liter ؊1 phenol within 70.5 h, was obtained on the basis of its capacity and hereditary stability for phenol biodegradation. The phenol hydroxylase gene sequences were cloned in wild and mutant strains. The results showed that four amino acids were mutated by irradiation with a laser. In order to compare the activity of phenol hydroxylase in wild and mutant strains, their genes were expressed in Escherichia coli BL21(DE3) and enzyme activities were spectrophotometrically determined. It was clear that the activity of phenol hydroxylase was promoted after irradiation with a He-Ne laser. In addition, the cell growth and intrinsic phenol biodegradation kinetics of mutant strain CTM 2 in batch cultures were also described by Haldane's kinetic equation with a wide range of initial phenol concentrations from 0 to 2,600 mg liter ؊1 . The specific growth and degradation rates further demonstrated that the CTM 2 mutant strain possessed a higher capacity to resist phenol toxicity than wild C. tropicalis did.

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