• KSBB Journal
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• v.11 no.2
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• pp.211-217
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• 1996

Batch experiments were conducted to investigate the effect of electron donor on reductive dechlorination of 2,4,5-trichlorophenol by a methanogenic consortium. The methanogenic consortium was obtained from the anaerobic digester of a municipal wastewater treatment plant. The batch reactor containing methanogenic consortium was spiked with 2,4,6-trichlorophenol at 10 mg/$\ell$. Acetate, ethanol, glucose of methanol, each was added as an electron donor for methanogenic consortium. During the course of the experiments liquid samples were taken from the batch reactor to measure dechlorination rate and find the dechlorination pathway of 2,4,6-trichlorophenol. After incubation 2,4,6-trichlorophenol was first dechlorinated to 2,4-dichlorophenol and then to 4-chlorophenol. Phenol was not detected in the batch reactor the highest rate of dechlorination of 2,4,6-trichlorophenol was observed when ethanol was used as an electron donor.

• Journal of Microbiology and Biotechnology
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• v.10 no.6
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• pp.759-763
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• 2000

Cell-free culture broth of Phanerochaete chrysosporium has been adopted to biologically degrade 2,4,5-trichlorophenol. Two different medium compositions of nitrogen-sufficient and nitrogen-limited were compared for their distribution of isozymes, activity of lignin peroxidase, and production of oxalate. The two different culture broths were tested for their ability to degrade 2,4,5-trichlorophenol, and the biodegradation efficiency was estimated in terms of the disappearance of 2,4,5-trichlorophenol. The degradation efficiency for the nitrogen-limited culture broth was higher than that of the nitrogen-sufficient culture broth, since the nitrogen-limited culture broth induced lignin peroxidases (LiPs) and manganese peroxidases (MnPs), and contained sufficient oxalate for producing necessary radicals. Finally, the possible mechanism of 2,4,5-CP degradation using the nitrogen-limited culture broth was proposed.

• Journal of Applied Biological Chemistry
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• v.63 no.2
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• pp.153-159
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• 2020

The analytical method was established for simultaneous determination of fungicide prochloraz and its metabolites in several animal commodities using gas chromatography (GC) coupled with electron capture detector (ECD). Samples including beef meat, pork meat, chicken meat, milk, and egg were hydrolyzed with pyridine hydrochloride which converts prochloraz and its metabolites to 2,4,6-trichlorophenol (2,4,6-TCP) because residue definition for prochloraz was 'sum of prochloraz and its metabolites containing the 2,4,6-trichlorophenol moiety, expressed as prochloraz', for compliance with MRLs from animal commodities. Therefore, residual prochloraz was extracted with acetone, decomposed to 2,4,6-TCP, partitioned with dichloromethane, purified with aminopropyl SPE and quantified as 2,4,6-TCP with GC-ECD. The instrumental limit of quantitation and method LOQ (MLOQ) was 0.01 ㎍/mL and 0.02 mg/kg for prochloraz and 0.005 ㎍/mL and 0.01 mg/kg for 2,4,6-TCP, respectively. The linearity of the calibration curve was good with R² >0.995 in the range of 0.005-0.2 ㎍/mL. Fortification levels of prochloraz were 0.02 mg/kg (MLOQ) and 0.2 mg/kg (10MLOQ) for recovery tests. Overall recoveries of prochloraz were >90% with <10% of coefficient variation (C.V.). This established analytical method was fully validated and could be useful for quantification of prochloraz and its metabolites in animal commodities as official analytical method.

• Analytical Science and Technology
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• v.14 no.1
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• pp.72-79
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• 2001

Oxidative decomposition of 2, 4, 6-trichlorophenol(TCP) was studied in aqueous solution. Iron and manganese protoporphyrin [or tetrakis(p-carboxyphenylporphyrin)] and their polymer supported derivatives were used as catalysts, and $KHSO_5$ and tert-butyldroperoxide(TBHP) as oxidants. Metalloporphyrin itself shows very poor catalytic activity in oxidative decomposition of TCP with oxidant. However, very high catalytic activity was observed when metalloporphyrin was chemically bound to newly synthesized polymers or XAD2 resin. Additionally, it revealed much higher catalytic activity in the presence of water-soluble polymers having a electron-donating axial ligand such as pyridine and immidazole. Maleic acid and chloromaleic acid were found in the resulting solution by ESI-MS. Especially, XAD2-supported metalloporphyrins can be reused as catalysts due to insolubility to solvent, and stability against oxidant.

• Analytical Science and Technology
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• v.18 no.4
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• pp.320-328
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• 2005

The most common five chlorophenols (4-chloro-3-methylphenol, 2,4,5-trichlorophenol, 2,4,6-trichlorophenol, 2,3,4,6-tetrachlorophenol, pentachlorophenol) were determined from the industrial wastewater by GC/MS. The samples were collected from the petrochemical company, textile company and leather making company. The developed analytical method was modified by USEPA Method 3510. The samples were extracted with dichloromethane under pH 2 and pH 5-6, and determined by the GC/MS with SIM mode. There were good linearities (above $R^2=0.9943$) on e ranges of the 0.1 ng/mL~10 ng/mL and 0.5 ng/mL~10 ng/mL, and the limit of detection were between 0.1 ng/mL and 0.5 ng/mL. The absolute recoveries were measured at the concentration of 1, 5, and 10 ng/mL, and the recovery was 71.6~98.9% except for PCP. The relative standard deviation (RSD) was 1.2~14.3% and it gave a good reproducibility for the assay. The bias, which shows the accuracy, was a good although it was a little high values (11.3~22.1%) at the low concentration (1 ng/mL).

• The Korean Journal of Pharmacology
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• v.2 no.2
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• pp.47-53
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• 1966

The bacteriostatic action of trichlorophenoxy alkylene ammonium derivatives, 2(2,4,5-trichlorophenoxy) ethylene N-triethyl ammonium bromide; (2,4,5-TETB), 2(2,4,6-trichlorophenoxy) ethylene N-triethyl ammonium bromide; (2,4,6-TETB), 2,4,5-triphenoxy ethylene pyridinium bromide; (2,4,5-TEPB), and 2,4,6-trichlorophenoxy ethylene pyridinium bromide:(2,4,6-TEPB) were observed by Jackson and Finland's and Finland's and Pak's on Staphylococcus aureus, E. coli, Salmonella typhi, Shigella flexneri, and Bacillus subtilis, comparing with those of phenol and trichlorophenol. The following results were obtained. 1) Phenol is bacteriostatic in a concentration of $10^{-3}$ for all above species. 2) Trichlorophenol is bacteriostatic in concentration of $10^{-4}$ to $5{\times}10^{-5}$ for all above species(Table 7), 3) 2,4,5-TETB and 2,4,6-TETB are bacteriostatic in a concentration of $10^{-4}$ and $5{\times}10^{-5}$ for Staphylococcus aureus, Salmonella typhi, and Shigella flexneri, but do not for E. coli and Bacillus subtilis(Table 8 and 9). 4) 2,4,5-TEPB and 2,4,6-TEPB are bacteriostatic in a concentrationof $10^{-4}$ and $5{\times}10^{-5}$ only for Staphylococcus aureus among four species(Table 10 and 11).

• Journal of Microbiology and Biotechnology
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• v.7 no.1
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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.

• Bulletin of the Korean Chemical Society
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• v.33 no.12
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• pp.4052-4058
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• 2012

The composite photocatalyst, N-$TiO_2$ loaded with $Ni_2O_3$, was prepared by $N_2$ plasma treatment. X-ray diffraction, X-ray fluorescence, $N_2$ adsorption, UV-vis spectroscopy, photoluminescence, and X-ray photoelectron spectroscopy were used to characterize the prepared $TiO_2$ samples. The results indicated that the band gap energy was decreased obviously by nitrogen doping, whereas loading of $Ni_2O_3$ did not influence the band gap and visible light absorption. The photocatalytic activities were tested in the degradation of 2,4,6-trichlorophenol (TCP) under visible light. The photocatalytic activity and stability of composite photocatalyst were much higher than that of catalyst modified with nitrogen or $Ni_2O_3$ alone. The synergistic effect of doping nitrogen and $Ni_2O_3$ over $TiO_2$ was investigated.

• Journal of Environmental Science International
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• v.29 no.1
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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.

• Proceedings of the Zoological Society Korea Conference
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• 1999.10b
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• pp.104.1-104
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• 1999

No Abstract, See Full Text