• Journal of Environmental Health Sciences
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• v.23 no.3
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• pp.121-129
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• 1997

This study was performed to delineate the removal phenol in solutions using of ozone, ozone/$H_2O_2$ and ozone/GAC. The disinfection by-product of phenol by ozonation, hydroquinone, was analyzed and it's control process was investigated. The followings are the conclusions that were derived from this study. 1. The removal efficiency of phenol by ozonation was 58.37%, 48.34%, 42.15%, and 35.41% which the initial concentration of phenol was 5 mg/l, 10 mg/l, 15 mg/l, and 20 mg/l, respectively. 2. The removal efficiency of phenol by ozonation was 42.95% at pH 4.0 and 69.39% at pH 10, respectively. The removal efficiencies were gradually increased, as pH values were increased. 3. With the ozone/$H_2O_2$ combined system, the removal efficiency of phenol was 72.87%. It showed a more complete degradation of phenol with ozone/$H_2O_2$ compared with ozone alone. 4. When ozonation was followed by filtration on GAC, phenol was completely removed. 5. Oxidation, if carried to completion, truly destroys the organic compounds, converting them to carbon dioxide. Unless reaction completely processed, disinfection by-products would be produced. To remove them, ozone/GAC treatment was used. The results showed that disinfection by-product of phenol by ozonation, hydroquinone, was completely removed. These results suggested that ozone/GAC should also be an appropriate way to remove phenol and its by-product.

• Journal of Environmental Health Sciences
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• v.45 no.1
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• pp.9-17
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• 2019

Objectives: This study examined the safety of tattoo ink by analyzing the phenol contents in tattoo inks and its risk assessment of selected phenol. Methods: A sample of 30 tattoo inks was purchased, the phenol contents were analyzed, and a risk assessment on dermal exposure from tattooing was carried out. Hazard identification was collected from toxicity data on systemic effects caused by dermal exposure to phenol, and the most sensitive toxicity value was adopted. Exposure assessment ($Exposure_{phenol}$) was calculated by applying phenol contents and standard exposure factors, while dose-response assessment was based on the collected toxicity data and skin absorption rate of phenol, assessment factors (AFs) for derived no-effect level ($DNEL_{demal}$). In addition, the risk characterization was calculated by comparing the risk characterization ratio (RCR) with $Exposure_{phenol}$ and $DNEL_{dermal}$ Results: The phenol concentration in the 30 products was from 1.4 to $649.1{\mu}g/g$. The toxicity value for systemic effects of phenol was adopted at 107 mg/kg. $Exposure_{phenol}$ in tattooing was from 0.000087 to 0.040442 mg/kg. $DNEL_{dermal}$ was calculated at 0.0072 mg/kg (=toxicity value 107 mg/kg ${\div}$ AFs 650 ${\times}$ skin absorption rate 4.4%). Thirteen out of 30 products showed an RCR between 1.02 and 5.62. The RCR of all red inks was above 1. Conclusions: Phenol was detected in all of the 30 tattoo inks, and the RCR of 13 products above 1 indicates a high level of risk concern, making it necessary to prepare safety management standards for phenol in tattoo inks.

• Journal of Environmental Health Sciences
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• v.24 no.3
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• pp.54-62
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• 1998

20 bacterial strains capable of growing on phenol minimal medium were isolated from soil and wastewater by the enrichment culture technique, and among them, one isolate which was the best in the cell growth was selected and identified as Bacillus sp. SH3 by its characteristics. Strain SH3 could grow with phenol as the sole carbon source up to 15 mM, but did not grow in minimal medium containing above 20 mM of phenol. The optimal conditions of temperature and initial pH for growth and phenol degradation were 30$^{\circ}$C and 7.5, respectively. This strain could grow on various aromatic compounds such as catechol, protocatechuic acid, gentisic acid, o-, m-, p-cresol, benzoic acid, p-hydroxybenzoic acid, anthranilic acid, phenyl acetate and pentachlorophenol, and the growth-limiting log P value of strain SH3 on organic solvents was 3.1. In batch culture, strain SH3 degraded 97% of 10 mM phenol in 48 hours. In continuous culture under the conditions of 20 mM of influent phenol concentration and 0.050 hr$^{-1}$ of dilution rate, the treatment rate of phenol was 94%.

• Journal of Environmental Health Sciences
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• v.21 no.2
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• pp.12-19
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• 1995

The objectives of this research prograln were to study the ozonation characteristics of phenol contaminated wastewater in the continuous packed column reactor (PCR) and the bubble column reactor (BCR) using ozone that has a strong oxidizing potential, and to provide the fundamentals of ozonizing the phenol contaminated wastewater. Among various influencing factors on phenol decomposition through the oxidation by ozone, phenol/ozone mde ratio was chosen as reaction parameters. Concerning the phenol/ozone mde ratio, as the influent phenol concentration increased from 30 mg/l to 150 mg/l, the phenol removal efficiency decreased from 99% for 30 mg/l to 83.7% for 150 mg/l, in PCR. PCR also showed higher treatment efficiency than BCR by 1% for 30 mg/l and 2.2% for 150 mg/l, respectively. The ozone utilization efficiency of PCR for the phenol concentration 30 mg/l was higher than that of BCR while the efficiency of both reactors was 99.9% for the phenol concentration of 150 mg/l.

• Journal of Environmental Science International
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• v.22 no.8
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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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• v.10 no.3
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• pp.335-342
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• 1995

Solid and liquid phase peroxidases were extracted from Chinese cabbage roots by using commercial juicer in order to use peroxidases from agricultural waste for industrial applications. Since peroxidases are distributed into 66% in liquid (juice) and 34% in solid phase (pulp), enzymes from both phases were applied to investigate the enzymatic removal of phenol from waste water. After contacting 150 ppm Phenol solution with liquid phase enzyme (1,800 unit/$\ell$) for 3 hours in a batch stirred reactor, 96% of phenol could be removed through polymerization and precipitation. Also, phenol could be removed from initial 120ppm to 5ppm by applying solid phase enzyme in an air lift reactor ($600 unit/\ell$). Almost equivalent efficiencies of phenol removal were observed between two systems, even though only one third of the enzymes in batch stirred reactor was applied in airlift reactor. The possible reason for this phenomenon is because peroxidases exist as immobilized forms in solid phase.

• Journal of Environmental Health Sciences
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• v.38 no.3
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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.

• Microbiology and Biotechnology Letters
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• v.6 no.4
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• pp.155-159
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• 1978

Phenol utilizing yeast No. 558 isolated from soil sewage sediment was able to use substantial amount of phenol as the sole carbon source, and the biomass productivity by this organism was very excellent. This organism could grow well in 1000 ppm of phenol concentration, the maxim-um specific growth rate obtainable at pH 5.0, 3$0^{\circ}C$ was 0.27/hr., and the biomass yield coefficient Y vs. consumed phenol was 3.2. Maximum production rate of biomass was observed at 35$^{\circ}C$, pH 3.5 to pH 4.5, and the addition of the 0.005~0. 01% yeast extract was the most effective. Addition of HgCl$_2$ and phenyl hydrazine, inhibitors of oxide-reductase, in the phenol containing cultural liquid caused this organism no-growth at the concentration of 10$^{-5}$ M, 10$^{-3}$ M respectively. This organism could utilize not only phenol but catechol, resorcinol and benzidine.

• Journal of Environmental Science International
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• v.25 no.7
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• pp.905-916
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• 2016

The characteristics of phenol removal and $UV_{254}$ matters variance were investigated and compared by the variation of operating factors (NaCl concentration, air flow rate, initial phenol concentration) in electrochemical reaction (ER) and dielectric barrier discharge plasma reaction (DBDPR), respectively. The phenol removal rate was shown as $1^{st}$ order both in ER and DBDPR. Also, the absorbance of $UV_{254}$ matters which means aromatic intermediates was analyzed to investigate the complete phenol degradation process. In ER, the phenol degradation and aromatic intermediates production rates increased by the increase of NaCl concentration. However, in DBDPR, the variation of NaCl concentration had no effect on the degradation of phenol and $UV_{254}$ matters. Air flow rate had a little effect on the removal of phenol and the variation of $UV_{254}$ matters in ER. The phenol removal rate in ER was a little higher than that in DBDPR. The produced $H_2O_2$ and $O_3$ amounts in ER were 2 times and 10 times higher than those in DBDPR. The chlorine intermediates ($ClO_2$ and free chlorine) were produced in ER, however, they were not produced in DBDPR.

• Microbiology and Biotechnology Letters
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• v.24 no.6
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• pp.743-748
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• 1996

For the biological treatment of phenolic resin wastewater containing phenol and formaldehyde, a phenol-degrading yeast was isolated from the papermill sludge, and then identified as Candida tropicalis PW-51 according to morphological, physiological and biochemical properties. The strain was able to degrade high phenol concentrations up to 2,000mg/l within 58 hours in batch cultures. Phenol-degrading efficiency by the strain was maximum at the culture conditions of a final concentration of 9 $\times$ 10$^{6}$ cells/ml, 30$\circ$C and pH 7.0. The mean degradation rate of phenol was highest at 45.5mg/l/h in 1,000mg/l phenol from 500mg/l to 2,000mg/l phenol. Because the enzyme activity of catechol 1,2-dioxygenase increased in the course of degradation of phenol, it seems that this strain degrades phenol via the ortho-cleavage of benzene ring. The isolate C. tropicalis PW-51 could be effectively used for the biological treatment of phenolic resin wastewater.