• 한국지하수토양환경학회지:지하수토양환경
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• 제22권1호
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• pp.41-48
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• 2017

Persulfate (PS) activated with nanosized zero-valent iron (NZVI) was tested as a reagent to remove phenol from groundwater. Batch degradation experiments indicated that NZVI/PS molar ratios between 1 : 2 and 1 : 5 were appropriate for complete removal of phenol, and that the time required for complete removal varied with different PS and NZVI dosages. Chloride ions up to 100 mM enhanced the phenol oxidation rate, and nitrate of any concentration up to 100 mM did not significantly affect the oxidation rate. NZVI showed greater performance than ferrous iron did as an activator for PS. A by-product was formed along with phenol degradation but subsequently was completely degraded, which showed the potential to attain mineralization with the NZVI/PS system. Tests with radical quenchers indicated that sulfate radicals were a predominant radical. The results of this study suggest that NZVI is a promising activator of PS for treating contaminated groundwater.

• Journal of Microbiology and Biotechnology
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• 제13권6호
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• pp.1001-1007
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• 2003

Metal ions contamination may inhibit microorganisms involved in the biodegradation of organic compounds and affect biodegradation rates. Therefore, it is likely that bioremediation of xenobiotics-contaminated soils and waste will require inoculation with efficient biodegrading microbial communities, with capabilities of being resistant to heavy metals as well. Two different transconjugants (Pseudomonas sp. KMl2TC and P. aeruginosa TC) were constructed by conjugation experiments. Results on MIC, induction and growth inhibition strongly indicated that arsenic-resistant plasmid, pKM20, could be mobilized, and the newly acquired phenotype of pKM20 was not only expressed but also well regulated, resulting in newly acquired resistances to $As^{5+},\;As^{3+},\;and\;Sb^{3+} in\;addition\;to\;Cd^{2+},\;Zn^{2+},\;and\;Hg^{2+}$. The phenol- degradation efficiencies of Pseudomonas sp. KMl2TC were maintained significantly even at high heavy metal concentrations at which these efficiencies of P. aeruginosa TC were completely impaired. The results in this study on the effects of heavy metals on phenol degradation, especially after conjugation, are the first ever reported. All the results described in this study encourage to establish a goal of making "designer biocatalysts" which could degrade certain xenobiotics in the area contaminated with multiple heavy metals.

• 환경위생공학
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• 제11권3호
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• pp.13-19
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• 1996

Packed bed reactor containing immobilized microorganisms which degraded phenol without growth was used to remove phenol from the synthetic wastewater. The effects of temperature, retention time(reactor volume/flow rate) and phenol concentration on the removal efficiency of phenol were investigated. The effect of temperature in the range of 20-30$\circ $C was negligible while retention time and phenol concentration influenced the removal of phenol significantly. When retention time was in the range of 1-1.5 hour, the removal efficiency of phenol was affected not by phenol concentration but by retention time itself while it was influenced by phenol concentration above 1.5 hour of retention time. The beads after 720 hours operation were swelled by 40 % in diameter which could be prevented by crosslinking with glutaraldehyde at the expense of cell activity.

• 한국환경보건학회지
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• 제24권3호
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• pp.54-62
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• 1998

20 bacterial strains capable of growing on phenol minimal medium were isolated from soil and wastewater by the enrichment culture technique, and among them, one isolate which was the best in the cell growth was selected and identified as Bacillus sp. SH3 by its characteristics. Strain SH3 could grow with phenol as the sole carbon source up to 15 mM, but did not grow in minimal medium containing above 20 mM of phenol. The optimal conditions of temperature and initial pH for growth and phenol degradation were 30$^{\circ}$C and 7.5, respectively. This strain could grow on various aromatic compounds such as catechol, protocatechuic acid, gentisic acid, o-, m-, p-cresol, benzoic acid, p-hydroxybenzoic acid, anthranilic acid, phenyl acetate and pentachlorophenol, and the growth-limiting log P value of strain SH3 on organic solvents was 3.1. In batch culture, strain SH3 degraded 97% of 10 mM phenol in 48 hours. In continuous culture under the conditions of 20 mM of influent phenol concentration and 0.050 hr$^{-1}$ of dilution rate, the treatment rate of phenol was 94%.

• 생명과학회지
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• 제23권10호
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• pp.1273-1279
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• 2013

방향족화합물들로 오염되어있는 토양 및 산업폐수를 포함한 각종 시료로부터 phenol에 분해활성이 높은 56균주를 순수분리 하였으며, 이들 분리 균주 중 균체생육과 phenol 분해활성이 가장 높은 균주인 GN13을 선별하였다. 분리균주 GN13은 형태학적, 생리학적 및 생화학적 특성을 조사한 결과 Neisseria 속 세균과 유사한 것으로 판명되어 최종적으로 Neisseria sp. GN13으로 명명하였다. 분리균주 Neisseria sp. GN13의 균체생육 및 phenol 분해를 위한 최적온도와 최적 pH는 각각 $32^{\circ}C$와 7.0였다. 유일 탄소원으로 phenol 1,000 mg/l를 포함하여 최적화된 배지를 사용한 jar-fermentor 배지에서 배양 30시간에 균체생육이 최대에 이르렀으며 배양 27시간째 거의 모든 phenol이 분해되었으며, catechol deoxygenase 활성측정에 의하여 Neisseria sp. GN13은 meta-와 ortho-pathway를 통하여 catechol 분해가 일어났다. Neisseria sp. GN13은 phenol 함유 인공폐수에서의 phenol 분해율은 배양 30시간 만에 97%의 phenol이 분해되는 것으로 나타났으며, 인공폐수에 대한 Neisseria sp. GN13과 활성슬러지 처리구에서의 TOC 제거효율은 각각 83%와 78%였다. 석유화학폐수에 대한 Neisseria sp. GN13의 COD 제거율은 활성슬러지만을 포함한 대조구보다 약 1.3배 높은 효율을 나타내었다. 이러한 결과로 미루어 분리균주 Neisseria sp. GN13은 phenol을 함유하고 있는 여러 폐수에 효과적으로 적용될 수 있을 것으로 생각된다.

• KSBB Journal
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• 제13권2호
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• pp.119-124
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• 1998

Twelve bacterial strains capable of growing on phenol minimal medium were isolated from iron foundry activated sludge by enrichment culture, and amount them, one isolate which was the best in cell growth and phenol degradation was selected and identified as Acinetobacter junii POH. The optimal temperature, initial pH and phenol concentration in the above medium were 3$0^{\circ}C$, 7.5 and 1000 ppm, respectively. Cell growth of Acinetobacter junii POH dramatically increased 20 hrs cultivation-time and reached a almost stationary phsae 40 hrs cultivation-time then phenol was degraded about 98%. Cell growth was inhibited y phenol at concentrations over 1500 ppm. The isolate was resistant to several antibiotics as well as various heavy metal ions. The growth-limiting log P value of Acinetobacter junii POH on organic solvents was 2.9 in the LB medium. Therefore, it is suggested that Acinetobacter junii POH could be effectively used for the biological treatment of wastewater containing the presence of heavy metal ions and organic solvents.

• Journal of Microbiology and Biotechnology
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• 제11권1호
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• pp.112-117
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• 2001

A nonconventional yeast strain Y103 capable of degrading several aromatic hydrocarbons was isolated from the wastewater of the Yocheon industrial complex. The strain Y103 was identified as Yarrowia lipolytica on the basis of its unique dimorphic and biochemical characteristics as determined by a Biolog test. Y. lipolytica Y103 was found to degrade phenol and 4-chlorophenol to produce catechol. The catechol then will be further degraded to produce 2-hydroxymuconic semialdehyde via meta-cleavage. These results indicate that strain Y103 degrades 4-chlorophenol, phenol, and catechol through a consecutive reaction to produce 2-hydroxymuconic semialdehyde. The most active degradation of phenol by Y. lipolytica Y103 occurred with a 0.5 mM phenl concentration in an MM2 medium at $30^{\circ}C$ and pH 7.0.

• Bulletin of the Korean Chemical Society
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• 제33권7호
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• pp.2274-2278
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• 2012

To test the efficiency of the BDD electrode for complete mineralization of organic wastewater, phenol and 2-chlorophenol (2-CP) were treated electrochemically with both an active Pt/Ti electrode and a nonactive boron doped diamond (BDD) electrode, respectively, in neutral aqueous medium. Aqueous solutions of both phenol and 2-chlorophenol were treated electrochemically using an in-house fabricated flow through electrochemical cell (FTEC). The experimental variables included current input, treatment time, and the flow rate of the solutions. Depending on the magnitude of the applied current and reaction time, the compounds were either completely degraded or partially oxidized to other intermediates. Removal efficiencies reached as high as 93.2% and 94.8% both at the Pt/Ti electrode and BDD electrode, respectively, at an applied current of 200 mA for a 3.0 hr reaction and a flow rate of 4 mL/min. The BDD electrode was much more efficient for the complete mineralization of phenol and 2-chlorophenol than the Pt/Ti electrode.

• 한국환경보건학회지
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• 제22권3호
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• pp.98-102
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• 1996

This study investigated performance of the phenol degradation and reaction characteristics according to variation of phenol volumetric loading rates and dilution rates in suspension and PACT reactors using Pseudomonas sp. B3. 1. Removal efficiencies of the PAC unit indicated about 100 % with phenol volumetric loading rates from 0.4 phenol $kg/ma^3\cdot d$ to 1.2 phenol $kg/m^3\cdot d$, however, which of the suspension reactor showed about 100% with from 0.2 phenol $kg/m^3\cdot d$ to 0.75 phenol $kg/ma^3\cdot day$. 2. The cell density slightly was decreased from 298.2 mg/l to 272 mg/l, when dilution rate for suspension was reactor increased from 0.4 to 1.41 1/d, and also the cell density suddenly was decreased to 145.5 mg/l and was washed out at the dilution rate higher than 1.60 1/d. But the cell density for the PAC unit was linearly decreased with dilution rate of from 0.8 to 3.0 1/d, and showed 220.75 mg/l at maximum dilution rate. 3. The phenol utilization rate was increased from 0.008 to 0.031 phenol g/l$\cdot$h, when dilution rate for suspension reactor was increased from 0.4 to 1.5 1/d, however, the rate for the PAC unit was linearly increased from 0.017 to 0.061 phenol g/l$\cdot$h as variation changes from 0.017 to 0.061 phenol g/l$\cdot$h dilution rate.

• Journal of Applied Biological Chemistry
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• 제50권4호
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• pp.221-226
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• 2007

The high molecular-weight mucilage extracted and purified from cactus fruit of Opuntia ficus-indica var. Saboten was degraded by the cell-free culture filtrate of a fungus isolated from soil. TLC analysis of the polymeric mucilage after incubation with the fungal culture filtrate confirmed its degradation. When the degradation products were tested for their qualitative reactions with ninhydrin and phenol-sulfuric acid, only phenol-sulfuric acid gave positive development, and ninhydrin did not show any observable color reaction. This coloring reaction suggested the presence of a carbohydrate without an amino group within the mucilage. Analyses by HPLC and liquid gel permeation chromatography on sephadex G-100 also provided additional information on degradation of the mucilage by the fungal culture filtrate. The sequences of ITS-5.8S rDNA from the fungal isolate that was cultivated for the preparation of mucilage-degrading enzyme showed 99% similarity to those of Pestalotiopsis aquatica.