• 한국환경과학회지
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• 제21권4호
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• pp.479-488
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• 2012

A Dielectric barrier discharge (DBD) plasma is shown in the present investigation to be effective of phenol degradation in the aqueous solutions in batch reactor with continuous air bubbling. Removal of phenol and effects of various parameters on the removal efficiency in the aqueous solution with high-voltage streamer discharge plasma are studied. The effect of 1st voltage (80 ~ 220 V), air flow rate (3 ~ 7 L/min), pH (3 ~ 11), electric conductivity of solution (4.16 ${\mu}S$/cm, deionized water) ~ 16.57 mS/cm (addition of NaCl 10 g/L) and initial phenol concentration (2.5 ~ 20.0 mg/L) were investigated. The observed results showed that phenol degradation was higher in the basic solution than that of the acidic. The optimum values on the 1st voltage and air flow rate for phenol degradation were 140 V and 6 L/min, respectively. It was considered that absorbance variation of $UV_{254}$ of phenol solution can be use as an indirect indicator of change of the non-biodegradable organic compounds within the treated phenol solution. Electric conductivity was not influenced the phenol degradation. To obtain the removal efficiency of phenol and COD of phenol over 97 % (initial phenol concentration, 10.0 mg/L), 80 min and 120 min were need, respectively. Phenol and COD degradation showed a pseudo-first order kinetics.

• 한국미생물·생명공학회지
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• 제22권2호
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• pp.203-209
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• 1994

The bacterial strain which utilizes phenol and degrade TCE was isolated from an industrial waste site. The bacterial strain was named as T5-7 and identified as an Acinetobacter species. After phenol-induction, the strain T5-7 removed TCE efficiently without cell growth. So, it seems that TCE degradation was not related to cell growth. TCE degradation increased when initial cell concentrations of phenol-grown T5-7 were high. In the presence of phenol, initial degradation of TCE was delayed but total amount of degradation was not affected at final stage. The strain cultured in 0.1% yeast extract did not degrade TCE, which indicates that phenol induction was essential to the TCE degradation.

• 한국미생물·생명공학회지
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• 제23권3호
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• pp.255-262
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• 1995

Intact cells of Acinetobacter sp. T5-7 completely degraded trichloroethylene (TCE) following growth with phenol. This strain could grow on at least eleven aromatic compounds, e.g., benzaldehyde, benzene, benzoate, benzylalochol, catechol, caffeic acid, 2.4-D, p-hydroxybenzoate, phenol, protocatechuate and salicylate, and did grow on alkane, such as octane. But except phenol, other aromatic compounds did not induced TCE degradation. Phenol biotransformation products, catechol was identified in the culture media. However, catechol-induced cells did not degrade TCE. So we assumed that phenol hydroxylase was responsible for the degradation of TCE. The isolate T5-7 showed growth in MM2 medium containing sodium lactate and catechol rather than phenol, but did not display phenol hydroxyalse activity, suggesting induction of enzyme synthesis by phenol. Phenol hydroxylase activity was independent of added NADH and flavin adenine dinucleotide but was dependent on NADPH addition. Degradation of phenol produced catechols which are then cleaved by meta-fission. We identified catechol-2.3-dioxygenase by active staining of polyacrylamide gel.

• 한국환경과학회지
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• 제22권8호
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• pp.999-1007
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• 2013

Electrochemical degradation of phenol was evaluated at DSA (dimensionally stable anode), JP202 (Ru, 25%; Ir, 25%; other, 50%) electrode for being a treatment method in non-biodegradable organic compounds such as phenol. Experiments were conducted to examine the effects of applied current (1.0~4.0 A), electrolyte type (NaCl, KCl, $Na_2SO_4$, $H_2SO_4$) and concentration (0.5~3.0 g/L), initial phenol concentration (12.5~100.0 mg/L) on phenol degradation and $UV_{254}$ absorbance as indirect indicator of by-product degraded phenol. It was found that phenol concentration decreased from around 50 mg/L to zero after 10 min of electrolysis with 2.5 g/L NaCl as supporting electrolyte at the current of 3.5 A. Although phenol could be completely electrochemical degraded by JP202 anode, the degradation of phenol COD was required oxidation time over 60 min due to the generation of by-products. $UV_{254}$ absorbance can see the impact of as an indirect indicator of the creation and destruction of by-product. The initial removal rate of phenol is 5.63 times faster than the initial COD removal rate.

• KSBB Journal
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• 제11권5호
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• pp.577-585
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• 1996

본 연구에서는 페놀 분해 능력이 있는 활성슬러지 를 광경화성 수지에 포괄 고정화하여 페놀 분해에 미치는 영향인자에 대하여 조사 검토하였다. 고정화 활성슬러지의 경우 free 활성슬러지 보다 넓은 pH 범위에서 페놀 분해 상대활성도가 높게 나 타났￡며, 고정화비드 직경이 작을수록 페놀분해 시 간이 짧았다. 페놀농도 2000 mg/L까지는 free 활 성슬러지의 분해시간이 짧았으나, 3000 mg/L에서 는 고정화 활성슬러지의 분해능이 높았다. 고정화비 드 주입량에 따른 페놀 분해성은 반융기 내에 주입 된 고정화비드양에 정비례 하지는 않았으나 주입량 이 많을수록 페놀 처리율이 높았다. 고정화 활성슬 러지의 반융에서는 반복샤용 7회 이상일 때의 상대 활성도는 처음의 약 8배 정도 증가하였다. 고정화 활성슬러지를 합성폐수 또는 증류수에서 진탕 또는 정지상태로 20일간 보관한 후에는 700 mg/L의 페놀이 24시간 후면 거의 분해되었으며, 증 류수에 정지된 상태로, 40일간 보관한 후에는 마찬가지로 24시간 후에 96.7 % 이상이 분해되었다. 또 한 고정화 활성슬러지를 합성폐수에서 호기적으로 보존하면 80일간 보존이 가능하였다. 고정화 활성슬러지를 사용한 연속처리에서는 용적 부하 5.59 kg-phenol/m3.d에서 95 % 이상의 페놀 이 제거되었으며, 연속실험에서 페놀제거 효율이 95 % 이상일 때 처리성척을 비교해보면, 고정화 활성 슬러지 빛 free 활성슬러지 용척부하는 각각 7.46, 3 3.72 kg-phenol/m3.day로써 고정화 활성슬러지가 2배 더 높은 부하에서 처리가 가능하였다.

• 한국환경보건학회지
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• 제38권3호
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• pp.251-260
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• 2012

Objectives: The purpose of this study was evaluating the applicability of the circulation dielectric barrier plasma process (DBD) for efficiently treating non-biodegradable wastewater, such as phenol. Methods: The DBD plasma reactor system in this study consisted of a plasma reactor (discharge, ground electrode and quartz dielectric tube, external tube), high voltage source, air supply and reservoir. Effects of the operating parameters on the degradation of phenol and $UV_{254}$ absorbance such as first voltage (60-180 V), oxygen supply rate (0.5-3 l/min), liquid circulation rate (1.5-7 l/min), pH (3.02-11.06) and initial phenol concentration (12.5-100 mg/l) were investigated. Results: Experimental results showed that optimum first voltage, oxygen supply rate, and liquid circulation rate on phenol degradation were 160 V, 1 l/min, and 4.5 l/min, respectively. The removal efficiency of phenol increased with the increase in the initial pH of the phenol solution. To obtain a removal efficiency of phenol and COD of phenol of over 97% (initial phenol concentration, 50.0 mg/l), 15 min and 180 minutes was needed, respectively. Conclusions: It was considered that the absorbance of $UV_{254}$ for phenol degradation can be used as an indirect indicator of change in non-biodegradable organic compounds. Mineralization of the phenol solution may take a relatively longer time than that required for phenol degradation.

• 한국환경과학회지
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• 제11권6호
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• pp.597-603
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• 2002

Photocatalytic degradation of phenol was carried out with UV-illuminated TiO$_2$-SiO$_2$ in aqueous suspension. TiO$_2$-SiO$_2$ catalysts were prepared by sol-gel method from the titanium isopropoxide and tetraethylorthosilicate at different Ti/Si ratio and some commercial TiO$_2$ catalysts were used as purchased. All catalysts were characterized by X-ray Diffraction(XRD) and BET surface area analyzer. The effect of reaction conditions, such as initial concentration of phenol, reaction temperature and catalyst weight on the photocatalytic activity was studied. In addition, TiO$_2$-SiO$_2$(49: 1) prepared by sol-gel method showed higher activity than commercial TiO$_2$catalysts on the photocatalytic degradation of phenol. The addition of SiO$_2$ into TiO$_2$hepled to increase the thermal stability of titania which suppressed the formation of anatase into rutile. The photocatalytic degradation of phenol showed pseudo-1st order reaction and the degradation rate increases with decreasing initial phenol concentration.

• 공업화학
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• 제17권1호
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• pp.100-105
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• 2006

$UV/TiO_2$ 허니컴 광촉매가 고정된 반응기에서 여러 운전 변수에 따른 페놀의 분해반응을 고찰하였다. 광촉매의 종류에 따른 페놀의 분해능을 비교한 결과, 이시하라사 STS-02로 코팅한 허니컴 광촉매는 데구사 P25에 비해 약간 높은 광산화 활성을 나타내 주었다. 반면에 국내 N사의 광촉매로 코팅한 허니컴의 경우에는 페놀의 광분해 효과가 거의 나타나지 않았다. 허니컴 광촉매는 데구사 P25의 코팅량이 증가함에 따라 페놀의 광산화 반응속도가 증가하는 경향을 나타내주었다. 데구사 P25로 코팅된 허니컴 반응기의 경우에 원수의 유량이 증가함에 따라 페놀의 광산화 속도가 지속적으로 증가하다가 500 mL/min 이상의 유속에서는 감소하는 경향을 나타내었다. 광촉매 표면이 페놀에 의해 미리 흡착된 경우에는 초기 반응시간에 자외선 조사에 의한 페놀의 부분산화 반응이 일어나 오히려 269 nm에서 페놀의 흡광도가 상승하는 결과를 나타내 주었다.

• 상하수도학회지
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• 제33권4호
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• pp.243-250
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• 2019

This objective of this study was to investigate the degradation characteristics of phenol, a refractory substance, by using a submerged dielectric barrier discharge (DBD) plasma reactor. To indirectly determine the concentration of active species produced in the DBD plasma, the dissolved ozone was measured. To investigate the phenol degradation characteristics, the phenol and chemical oxygen demand (COD) concentrations were evaluated based on pH and the discharge power. The dissolved ozone was measured based on the air flow rate and power discharged. The highest dissolved ozone concentration was recorded when the injected air flow rate was 5 L/min. At a discharge power of 40W as compared to 70W, the dissolved ozone was approximately 2.7 - 6.5 times higher. In regards to phenol degradation, the final degradation rate was highest at about 74.06%, when the initial pH was 10. At a discharged power of 40W, the rate of phenol decomposition was observed to be approximately 1.25 times higher compared to when the discharged power was 70W. It was established that the phenol degradation reaction was a primary reaction, and when the discharge power was 40W as opposed to 70W, the reaction rate constant(k) was approximately 1.72 times higher.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2002년도 생물공학의 동향 (X)
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• pp.431-434
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• 2002

단일균이나 활성슬러지를 이용하여 폐수를 처리하고자 할 때 폐수의 pH 가 단일균이나 활성 슬러지의 최적 pH 에 적합하지 아니한 경우에는 미생물을 고정화하여 희망하는 pH에서 최대의 분해활성을 나타내도록 최적 pH를 어느정도 변화시킬 수 있으며, 기존의 활성슬러지법 보다는 활성 슬러지를 고정화하여 처리하는 것이 높은 부하에서도 제거 효율이 높기 때문에 반응조의 콤펙트화가 가능할 것으로 사료된다.