• Membrane and Water Treatment
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• 제11권3호
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• pp.195-200
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• 2020

In this study, a biocatalyst composite was prepared by immobilizing oxidoreductases onto Cu-activated zeolite to facilitate biochemical decomposition of 4-chlorophenol (4-CP). 4-CP monooxygenase (CphC-I) was cloned from a 4-CP degrading bacterium, Pseudarthrobacter chlorophenolicus A6, and then overexpressed and purified. Type X zeolite was synthesized from non-magnetic coal fly ash using acetic acid treatment, and its surfaces were coated with copper ions via impregnation (Cu-zeolite). Then, the recombinant oxidative and reductive enzymes were immobilized onto Cu-zeolite. The enzymes were effectively immobilized onto the Cu-zeolite (79% of immobilization yield). The retained catalytic activity of CphC-I after immobilization was 0.3423 U/g-Cu-zeolite, which was 63.3% of the value of free enzymes. The results of this study suggest that copper can be used as an effective enzyme immobilization binder because it provides favorable metalhistidine binding between the enzyme and Cu-zeolite.

• 한국세라믹학회지
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• 제41권6호
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• pp.485-492
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• 2004

비정질알루미나와 기공형성제를 물과 혼합하여 원통형으로 성형하고 수화, 건조 및 소성하여 직경 5mm의 ${\gamma}$알루미나 펠릿을 제조하였다. 이를 Fe$(NO_{3})_{3}$.$9H{2}O$ 용액과 $CH{3}COOH$ 혼합용액에 침척시키고 $200^{\circ}C$ 온도로 3시간 수열처리 하여 펠릿을 담지시킨 후 건조와 소성공정을 통하여 촉매를 제조하였다. 이와 같이 수열법에 의해 제조딘 산화철 담지${\gamma}$알루미나 촉매를 환경촉매로 적용하기 위해 4-chlorophenol과 같은 난분해성물질을 촉매를 사용하지 않는 오존단독공정과 촉매를 사용하는 촉매오존(catalytic ozonation)공정으로 구분하여 OH 라티칼 전환반응 개시제로서의 기능과 그 분해특성을 비교하였다.

• 한국환경과학회지
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• 제22권9호
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• pp.1089-1095
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• 2013

The degradation of 3-chlorophenol(3-CP) by various AOPs(Advanced Oxidation Processes) including the ultraviolet / hydrogen peroxide, the Fenton and the ultraviolet(UV)-Fenton process has been conducted. The highest removal efficiency for 3-CP in the aqueous phase was obtained by the UV-Fenton process among the AOPs. In the UV-Fenton process, The removal efficiency of 3-CP decreased with increasing pH in the range of 3 to 6, and it decreased with increasing initial concentration. As the intermediates of 3-CP by UV-Fenton reaction, 3-chlorocatechol, 4-chlorocatechol, and chlorohydroquinone were detected thus the degradation pathways were proposed.

• 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.

• 약학회지
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• 제24권2호
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• pp.87-95
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• 1980

Chlorination to polluted water can produce chlorocompounds which may impair human health. It has been discussed that chlorophenols would be one of undesirable substances in drinking water. This study was undertaken to investigate the production mechanism of chlorophenols by chlorination in the disinfection of water and to determine pollution levels of phenols as precursor of chlorophenols and chloropbenols in some sewage, stream water and tap water in the vicinity of Seoul from January to September, 1979. By chlorination with hyperchlorite to phenols in distilled water, o-chlorophenol was predominantly produced at the concentration of less than 10ppm of free chlorine. o-Chlorophenol, 2,6-dichlorophenol and 2,4-dichlorophenol were also produced by chlorination with the concenration from 20 to 100ppm of free chlorine. From the concentration of 100ppm of free chlorine to 200ppm, o-Chlorophenol was vanished and 2,6-dichlorophenol and 2,4-dichlorophenol were determined. Phenols originated from night soil, municipal sewage and stream were determined at 49.15 ppm. 0.095 ppm and 0.003 ppm in average respectively. About 87 and 88 percent of phenols in sewage and night soil were biodegradated by aeration for 10 days and 74 and 51 percent of phenols in sewage and night soil by spontaneous settling for 10 days. From the tap water in Seoul during summer, 1979, chlorophenols were identified; they were average 0.042 ppb of o-chlorophenol, 0.033 ppb of 2, 6-dichlorophenol and 0.003 ppb of 2, 4-dichlorophenol respectively. With the above result and discussion, it is considered that chlorophenols should be controlled from the source as well as chlorination in water purification.

• 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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• 제3권1호
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• pp.65-76
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• 1994

자연호소의 혐기성 저질을 특정한 chlorophenol(CP)에 적응시킨 후 다른 구조물 가진 CP에 대한 탈염소 특성을 검토하였다. CP에 노출되지 않는 혐기성 저질에서는 mono-CP의 경우 ortho > meta > para-염소의 손으로 di-CP의 경우는 ortho > par > meta- 염소의 순서로 짧은 지체기를 거친 후 탈염소가 발생하였다. Mono-CP 중 2-CP에 적응된 저질은 4-CP와 3,4DCP를 제외하고, 3-CP에 적응시킨 저질은 4-CP를 제외한 모든 시험물질에 대하여 지체기 없이 탈염소 특성을 나타내었다. DCP에 적응된 모든 저질은 2-CP, 2,3,-, 2,4-, and 3,4-DCP를 지체기 없이 탈염소가 발생하지 않았다. 이 결과에서 볼 때 mono-와 di-CP를 탈염소시키는 혐기성 미생물의 종류가 다양함을 알 수 있다.

• 한국환경생물학회:학술대회논문집
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• 한국환경생물학회 2004년도 학술대회
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• pp.68-68
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• 2004

• 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.

• 한국미생물·생명공학회지
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• 제30권3호
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• pp.287-292
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• 2002

본 연구에서는 경안천 유역에 있는 주유소 오염토양으로부터 대표적인 아조계 염료 congo-red분해능이 우수한 토양 방선균, SMA-2를 분리 선별하고, SMA-2의 배양조건을 최적화하여 2,4-dichlorophenol의 산화에 관여하는 actinomycetes lignin peroxidase(ALiP)의 활성도에 대한 특성을 규명하였다. 기존에 보고된 방선균 유래 ALiP와는 달리, SMA-2유래 ALiP효소는 pH6에서 최고의 활성을 보였으며, 2,4-DCP와 $H_2$$O_2$에 대한 Km값이 각각 0.21mM과 8.5mM로 측정되었다. 또한 최적화된 배지에서 성장한 SMA-2의 배양액은 2,4-dichlorophenol 뿐만 아니라 2-chlorophenol, 2,4,6-trichlorophenol, 2,6-dichlorophenol, phenol, 4-chloropheno떼 대해서도 산화능을 보임으로써, 토양 방선균을 이용한 염화 페놀계 화합물이 포함된 오염 토양의 생복원 가능성을 제시하였다.