• Bulletin of the Korean Chemical Society
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• 제22권11호
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• pp.1183-1191
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• 2001

The metallorganic chemical vapor deposition (MOCVD) method has been used to prepare TiO2 thin films for the degradation of hazardous organic compounds, such as 2-chlorophenol (2-CP). The effect of supporting materials and metal doping on the photocatalytic activity of TiO2 thin films also has been studied. TiO2 thin films were coated onto various supporting materials, including stainless steel cloth(SS), quartz glass tube (QGT), and silica gel (SG). Transition metals, such as Pd(II), Pt(IV), Nd(III) and Fe(III), were doped onto TiO2 thin film. The results indicate that Nd(Ⅲ) doping improves the photodegradation of 2-CP. Among all supporting materials studied, SS(37 ${\mu}m)$ appears to be the best support. An optimal amount of doping material at 1.0 percent (w/w) of TiO2-substrate thin film gives the best photodegration of 2-CP.

• Journal of Microbiology and Biotechnology
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• 제7권1호
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• pp.43-48
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• 1997

Three strains capable of degrading a chlorophenol were isolated by selective enrichment from soils contaminated with industrial wastewater. A Pseudomonas solanacearum TCP114 could use 2,4,6-trichlorophenol (TCP) as sole carbon and energy source, while two strains of Pseudomonas testosteroni CPW301 and Arthrobacter ureafaciens CPR706 could use 4-CP. All isolates also grew well on phenol. The degradation of one component by a pure strain was strongly affected by the presence of other compounds in the medium, CPW301 and CPR706 entirely lost the ability to degrade 4-CP and phenol in the presence of TCP. TCP114 also lost the ability to degrade phenol when 4-CP was added to the culture medium. These restrictions on the degradability could be overcome by employing defined mixed cultures (TCP114 and one strain of 4-CP degrading strains). All three components were successfully degraded by defined mixed cultures through their cooperative activities. It was also demonstrated that defined mixed cultures could be immobilized by using calcium alginate for the semi-continuous degradation of the three component mixture. Immobilization could not only accelerate the degradation rate, but also allowed the reuse of the cell mass several times without loss of the cells' degrading capabilities.

• 대한환경공학회지
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• 제27권3호
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• pp.273-279
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• 2005

본 연구에서는 초임계수 중에서 o-chlorophenol(o-CP)의 분해 및 중간 생성물 형성에 미치는 NaOH의 효과를 검토하였다. NaOH를 첨가하지 않은 경우 o-CP의 분해율은 20% 이하로 낮았으나 NaOH를 o-CP의 몰 농도에 대하여 200% 이상 첨가한 경우 체류 시간 1초 이내에 100% 가까운 분해율을 얻을 수 있었다. 분해 과정에서 생성되는 PAHs 및 페놀 화합물의 양도 크게 감소하는 경향을 나타내어 NaOH 첨가가 부산물 생성 억제에도 효과가 있는 것으로 나타났다. NaOH를 첨가하지 않은 경우와 첨가한 경우 공통적으로 페놀, 크레졸, 염화 페놀류, PAHs 및 1-indanone, dibenzofuran, dibenzo-dioxin, p,p'-dihydroxybiphenyl 등과 같이 2개 이상의 벤젠 고리가 산소로 연결된 화합물이 검출되었다. 반면에 NaOH를 첨가한 경우에는 2-ethylphenol, o-hydroxyacetophenone, hydroquinone, 4-allylphenol, 3-phenoxyphenol 및 4,4'-oxybisphenol이 생성되어 NaOH 첨가로 인한 o-CP의 분해는 훨씬 더 복잡한 과정을 통해서 이루어지는 것으로 판단되었다. 또한 페놀의 소각 과정에서 생성되는 것으로 보고된 화합물인 dibenzofuran, dibenzo-p-dioxin 등도 본 연구에서도 생성된 것으로부터 소각과 초임계수에 의한 열분해 사이에는 상관성이 있는 것으로 판단되었다.

• Bulletin of the Korean Chemical Society
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• 제33권9호
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• pp.3009-3016
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• 2012

This study evaluated the use of iron-impregnated SBA-15 (Fe/SBA-15) as a catalyst for the oxidative degradation of persistent phenol analogues, such as 2-chlorophenol (2-CP), 4-chlorophenol (4-CP), 2-nitrophenol (2-NP), 4-nitrophenol (4-NP) and 2,4,6-trichlorophenol (2,4,6-TCP) in water. The oxidation reactions were carried out with reaction time, concentration of the phenols, amount of the catalysts, reaction temperature, pH of the reaction mixture as the process variables with or without using hydrogen peroxide as the oxidizing agent. The conversion achieved with Fe/SBA-15 at 353 K for 2-CP, 4-CP, 2-NP, 4-NP, 2,4,6-TCP was 80.2, 71.2, 53.1, 62.8, 77.3% in 5h with a reactant to $H_2O_2$ mole ratio of 1:1, and 85.7, 65.8, 61.9, 63.7, 78.1% in the absence of $H_2O_2$, respectively. The reactions followed pseudo first order kinetics. The leachability study indicated that the catalyst released very little iron into water and therefore, the possibility of secondary pollution is negligible.

• 상하수도학회지
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• 제25권4호
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• pp.463-469
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• 2011

The degradation of 4-chlorophenol by various AOPs(Advanced Oxidation Processes) including the Fenton and the photo-Fenton process has been examined. In sole Fe, UV or $H_2O_2$ process without combination, low removal efficiencies have been achieved. But the photo-Fenton process showed higher removal efficiency for degradation of 4-chlorophenol than those of other AOPs including the Fenton process. Generally more hydrogen peroxide was required to achieve higher removal efficiencies of 4-CP at constant dosage of $FeSO_4$ in both of the Fenton and the photo-Fenton processes. Based on the results, The photo-Fenton process is proposed to be the most efficient alternative for degradation of 4-chlorophenol among the processes studied in this research.

• Environmental Engineering Research
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• 제11권4호
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• pp.217-231
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• 2006

The gas-phase formation of polychlorinated naphthalenes (PCNs) and dibenzofurans (PCDFs) was experimentally investigated by slow combustion of the three chlorophenols (CPs): 2-chlorophenol (2-CP), 3-chlorophenol (3-CP) and 4-chlorophenol (4-CP), in a laminar flow reactor over the range of 550 to $750^{\circ}C$ under oxidative condition. Contrary to the a priori hypothesis, different distributions of PCN isomers were produced from each CP. To explain the distributions of polychlorinated dibenzofuran (PCDF) and PCN congeners, a pathway is proposed that builds on published mechanisms of PCDF formation from chlorinated phenols and naphthalene formation from dihydrofulvalene. This pathway involves phenoxy radical coupling at unsubstituted ortho-carbon sites followed by CO elimination to produce dichloro-9, 10-dihydrofulvalene intermediates. Naphthalene products are formed by loss of H and/or Cl atoms and rearrangement. The degree of chlorination of naphthalene and dibenzofuran products decreased as temperature increased, and, on average, the naphthalene congeners were less chlorinated than the dibenzofuran congeners. PCDF isomers were found to be weakly dependent to temperature, suggesting that phenoxy radical coupling is a low activation energy process. Different PCN isomers, on the other hand, are formed by alternative fusion routes from the same phenoxy radical coupling intermediate. PCN isomer distributions were found to be more temperature sensitive, with selectivity to particular isomers decreasing with increasing temperature.

• 대한화학회지
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• 제58권3호
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• pp.289-296
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• 2014

Electrochemical copolymerization of o-chlorophenol (oCP) with o-hydroxyphenol (oHP) was carried out in aqueous $H_2SO_4$ by using cyclic voltammetry (CV) technique. In addition, CV was used to evaluate the differences in electrochemical characteristics of the copolymer in comparison with the corresponding homopolymers, poly(o-chlorophenol) (PoCP) and poly(o-hydroxyphenol) (PoHP). The variation of peak currents with respect to sweep rates was compared between copolymer and homopolymers, PoCP and PoHP, films. Further support for copolymer characterization was obtained by recording UV-visible, IR spectra and elemental analysis. The mechanism of the electrochemical polymerization has been discussed. The monomer reactivity ratios ($r_1$ and $r_2$) were calculated using Fineman-R$\ddot{o}$ss method and was found to be 0.4 and 1.3 repetitivelly and the copolymer structure is a block structure and more rich in oHP units.

• 한국환경과학회지
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• 제29권1호
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• pp.69-77
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• 2020

Oxidative degradation of phenol, three monochlorophenols (2-chlorophenol, 2-CP; 3-chlorophenol, 3-CP; 4-chlorophenol, 4-CP), four dichlorophenols (2,3-dichlorophenol, 2,3-DCP; 2,4-dichlorophenol, 2,4-DCP; 2,5-dichlorophenol, 2,5-DCP; 2,6-dichlorophenol, 2,6-DCP), and two trichlorophenols (2,4,5-trichlorophenol, 2,4,5-TCP; 2,4,6-trichlorophenol, 2,4,6-TCP) was conducted with heat activated persulfate. As the number of chlorinations increased, the reaction rate also increased. The reaction rate was relatively well fitted to the zero-order kinetic model, rather than the pseudo-first order kinetic model for the reactions at 60 ℃, which can be explained by insufficient activation of the persulfate at 60 ℃, and the oxidation reaction of 2,4,6-TCP at 70 ℃ was relatively well fitted to the pseudo-first order kinetic model. The oxidation reaction rate generally increased with increase of persulfate concentration in the solution. 2,6-dichloro-2,5-cyclohexadiene-1,4-dione was found as a degradation product in a GC/MS analysis. This compound is a non-aromatic compound, and one chlorine was removed. This result is similar to the result of previous studies. The current study proved that heat activated persulfate activation could be an alternative remediation technology for phenol and chlorophenols in soil and groundwater.

• 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.

• 대한환경공학회지
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• 제28권5호
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• pp.487-493
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• 2006

본 연구에서는 지하수에 존재하는 다양한 클로로페놀류 화합물을 제거하기 위하여 니켈로 코팅된 영가철을 이용하여 적용 타당성을 검토하였다. 다섯가지 종류의 클로로페놀 화합물을 대상으로 처리효과를 평가하였으며 중간 생성물을 분석하였다. 실험결과를 이용하여 개질된 영가철에 의한 반응경로 및 반응율을 평가하기 위하여 수치해석적 방법을 적용하였다. 개질된 영가철에 의한 오염물의 제거는 반응계수를 기준으로 2-CP>4-CP>2,4-DCP>2,4,6-TCP>2,6-DCP의 순서를 나타내었다. 수치해석 결과 각 클로로페놀 화합물의 탈염소화 반응은 연속적 단계와 평행적 단계를 거쳐 최종 생성물인 페놀화합물에 도달되는 결과를 보여주었다.