• Journal of Korean Society of Environmental Engineers
• /
• v.32 no.9
• /
• pp.900-904
• /
• 2010

Polyvinyl chloride (PVC) hoses, polyethylene hose and silicone hose for tap water were tested with respect to migration of phenolic compounds to water. The highest concentrations (0.36~1.97 mg/L) of total phenolic compounds were observed in the test water from PVC hoses. Increasing residual Cl concentration from 0 to 0.5 mg/L or increasing water temperature from 4 to $25^{\circ}C$ increased 3~3.2 times and 100~104 times for migrated total phenolic compounds concentrations, in respectively. A major migrating phenolic compounds from PVC hoses were bisphenol-a (BPA) and it was observed that the concentration of migrating phenolic compounds in the order: DEHP > 2-chlorophenol > 2,4,6-trichlorophenol > 2,4-dichlorophenol from PVC hoses.

• Analytical Science and Technology
• /
• v.30 no.1
• /
• pp.20-25
• /
• 2017

An analytical method for determining potential endocrine disruptors (bisphenol A, 2-chlorophenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol, pentachlorophenol, p-t-butylphenol, p-pentylphenol, p-hexylphenol, p-t-octylphenol, p-heptylphenol, nonylphenol) by solid-phase extraction (SPE) and High Perfomance Liquid Chromatography(HPLC) equipped with fluorescence and variable wavelength detector has been developed. The SPE process for sample concentration was performed on a commercially available Oasis HLB cartridge packed with polymeric sorbents. The effect of elution solvent and elution volume on the recoveries of the analytes were investigated with HPLC. Average recovery of >85% was achieved with 60mg sorbents using 5mL of methanol as elution solvent. Phenolic compounds in canned drinks, beverages and water samples were surveyed by this proposed method.

• Bulletin of the Korean Chemical Society
• /
• v.33 no.9
• /
• pp.3009-3016
• /
• 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.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2004.04a
• /
• pp.186-191
• /
• 2004

Sorption kinetics of 2-chlorophenol(2-ChP), 2,4-dichlorophenol(2,4-DChP) and 2,4,5-trichlorophenol (2,4,5-TChP), onto montmorillonite modified with hexadecyltrimethyl ammonium cations(HDTMA-mont) were investigated. One-site mass transfer model(OSMTM) and two compartment first-order kinetic model(TCFOKM) were used to analyze kinetics. As expected from the number of model parameters involved, the three-parameter TCFOKM was better than the two-parameter OSMTM in describing sorption and desorption kinetics of chlorophenols in HDTMA-mont. For all chlorophenols, the results of OSMTM analysis indicate that the predominant deprotonated speciation(at pH 9.15) exhibited higher mass transfer coefficient( $k_{s}$ ) than the protonated speciation(at pH 4.85). This is because the deprotonated speciation has stronger hydrophobic interaction than protonated speciation. Most sorption completes in three hours. The fraction of the fast sorption and the first-order sorption rate constants for the fast and slow compartments in TCFOKM were determined by fitting experimental data to the TCFOKM. The results of kinetics reveal that the fraction of the fast sorption( $f_1$) and the sorption rate constants in the fast compartments( $k_1$) were in the order 2,4,5-TChP > 2,4-DChP > 2-ChP, which agrees with the magnitude of the $K_{ow}$ . The first-order sorption rate constants in the fast compartment(10$^{0.8}$ - 10$^{1.22}$ h $r^{-1}$ ) were much larger than those in the slow compartment(10$^{-1}$.74/ - 10$^{-2}$.622/ h $r^{-1}$ ).> ).).

• Journal of Korean Society of Water and Wastewater
• /
• v.12 no.1
• /
• pp.88-95
• /
• 1998

The Electron/Hole Pair is generated when the Activation Energy produces by Ultraviolet Ray illumination to the Semiconductor. And $OH^-$ ion produces by Water Photo-Cleavage reacts with Positive Hole. As a result, OH Radical acting as strong oxidant is generated and then Photocatalytic Oxidation Reaction occurs. The Photocatalytic Oxidation can oxidize the chlorophenol to Chloride and Carbon Dioxide easier, safer and shorter than conventional Water Treatment Process With the same degree of chlorination, the $Cl^-$ ion at para (C4) position is most easily replaced by the OH radical. And then, the blocking effect of $OH^-$ ion between the $Cl^-$ ions and $Cl^-$ ions at symmetrical location is easily replaced by the OH radical. For mono-, di-, tri-chlorophenols, there is no obvious difference in decomposition rate, decomposition efficiency and completeness of the decomposition reaction except for 2,3-dichloropheno, 2,4,5-, 2,3,4-trichlorophenol. The decomposition efficiency is higher than 75% and completeness of the decomposition reaction is higher than 70%. Therefore, continuous flow photocatalytic reactor is promising process to remove the chlorinated aromatic compounds which is more toxic than non-chlorinated aromatic compound.

• Journal of Korean Society of Environmental Engineers
• /
• v.27 no.1
• /
• pp.67-74
• /
• 2005

Toxicity tests were performed to evaluate the feasibility of application with prediction models to 10 mixture chemicals (chloroneb, butylbenzylphthalate, pendimethaline, di-n-butylphthalate, di-iso-butylphthalate, diazinon, isofenphos, 2-chlorophenol, 2,4,6-trichlorophenol and p-octylphenol) detected in effluents from wastewater treatment plants (WWTPs). Ten chemicals were selected in the basis of their toxicities to Daphnia magna and the concentrations in effluents measured by GC/MS. Three models including concentration addition (CA), independent action (IA) and effect summation (ES) were employed for the comparison of the predicted and the observed mortality of D. magna exposed to 10 mixture chemicals for 48 hours. With a comparative study it was ineffective to predict the mortality through the CA and the ES prediction model, while the IA prediction model showed a high correlation($r^2\;=\;0.85$). Moreover, the ES model over-estimated the toxicity observed by bioassay experiments about five-fold. Consequently, IA model is a reasonable tool to predict the mixture toxicity of the discharging water from WWTPs.

• Microbiology and Biotechnology Letters
• /
• v.30 no.3
• /
• pp.287-292
• /
• 2002

Lignin-peroxidase (LiP) has been considered as one of the most important industrial enzymes for biodegradation of various recalcitrant toxic compounds such as chlorinated aromatic hydrocarbons and azo-dyes. Recently, several soil actinomycetes have been reported to secrete a functionally-similar lignin-peroxidase called actinomycetes lig-nin-peroxidase (ALiP). In this manuscript, we isolated over 100 morphologically distinct actinomycetes from the contaminated soils around 10 different gas stations located nearby the Kyung-An river. Among these actinomycetes screened based on the congo-red dye-decolorization activities, one newly-isolated actinomycetes named SMA-2 showed the most significant dye-decoloring activity on the congo-red plate as well as a significant ALiP activity in a yeast-extract-malt-extract liquid media supplemented with starch. The optimum SMA-2 culture condition fur ALiP production was determined and the kinetic parameters fur the SMA-2 AkIP activity were characterized. The optimally-cultured SMA-2 also exhibited the oxidation activities toward various recalcitrant aromatic compounds including phenol, 2- chlorophenol, 4- chlorophenol, 2,4- dichlorophenol ,2,6- dichlorophenol, and 2,4, f-trichlorophe - not, suggesting a potential application of SMA-2 for contaminated soil bioremediation.

• Korean Journal of Environmental Agriculture
• /
• v.40 no.4
• /
• pp.353-358
• /
• 2021

BACKGROUND: Prochloraz has been widely used as an imidazole fungicide on fruits and vegetables in Korea. Analytical approaches to evaluate prochloraz residues in herbal medicine are required for their safety management. In this study, we developed a GC-ECD method for quantitative determination of prochloraz in Platycodi Radix. The metabolite 2,4,6-trichlorophenol (2,4,6-T) was used as a target compound to evaluate total prochloraz residues as it is categorized to a representative residue definition of prochloraz. All residues containing 2,4,6-T were converted to 2,4,6-T and subjected to GC-ECD. METHODS AND RESULTS: In order to verify the applicability, the method was optimized for determining prochloraz and it metabolite 2,4,6-T in Platycodi Radix. Prochloraz and its metabolite 2,4,6-T residuals were extracted using acetone. The extract was diluted with and partitioned directly into dichloromethane to remove polar co-extractives in the aqueous phase. The extract was decomposed to 2,4,6-T, and then the partitioned ion-associate was finally purified by optimized aminopropyl solid-phase extraction (SPE). The limits of quantitation of the method (MLOQs) were 0.04 mg/kg and 0.02 mg/kg, respectively for prochloraz and 2,4,6-T, considering the maximum residue level (MRL) of prochloraz as 0.05 mg/kg in Platycodi Radix. Recovery tests were carried out at two levels of concentration (MLOQ, 10 MLOQ) and resulted in good recoveries (82.1-89.7%). Good reproducibilities were obtained (coefficient of variation < 2.8%), and the linearities of calibration curves were reasonable (r² > 0.9986) in the range of 0.005-0.5 ㎍/mL. CONCLUSION(S): The method developed in this study was successfully validated to meet the guidelines required for quantitative determination of pesticides in herbal medicine. Thus, the method could be useful to monitor prochloraz institutionally in herbal medicine.

• Korean Journal of Environmental Agriculture
• /
• v.15 no.1
• /
• pp.37-45
• /
• 1996

Abstracts From the previous metabolic study of Pentachlorophenol(PCP), PCP was found to be exclusively transformed into ${\beta}-glucose$ conjugates of PCP in soybean and rice cell suspension cultures. In order to gather structural information of of the glucose conjugate, their aglycons and glycon have been analyzed by GC and GC/MS respectively, after thorough purification by chromatographic techniques. The glucose conjugates were effectively purified through a 1-butanol extraction followed by Silica gel TLC, Sephadex column chromatography and HPLC. Aglycons of the metabolites were identified as PCP, isomeric mixture of tetrachlorophenol, and tetrachlorocatechol and glycon were identified as glucose, suggesting that there are at least three kinds of glucose conjugates with different phenolic moieties. Under controlled conditions, the glucose conjugates were separated into three HPLC peaks which released respective aglycon upon a hydrolytic treatment. These results give valuable information on the structure of the glucose conjugates such that some PCP-driven chlorophenols, in addition to PCP, are also conjugated with glucose.

• Korean Journal of Environmental Agriculture
• /
• v.28 no.4
• /
• pp.427-434
• /
• 2009

Analytical method for prochloraz in cabbage, apple, pepper, mandarin, and hulled rice was established by conversion it to 2,4,6-trichlorophenol (TCP). Crop samples were extracted with acetonitrile, and partitioned with dichloromethane. The sample extracts were hydrolyzed with pyridine hydrochloride in a vial by heating for 1 hour, and analyzed with GC-ECD after partitioning with dichloromethane. Method quantification limit (MQL) of prochloraz was 0.01 mg/kg. Recoveries at 0.1 mg/kg level was 105-113% while at 0.5 mg/kg level was 82-87%. In both of the cases CV was less than 10%. Through this procedure soxhlet extraction and refluxing apparatus of conventional method were discarded and simple solvent extraction and small vial were successfully employed, resulting in simple, rapid, economic and more precise method.