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

• Journal of Microbiology
• /
• v.45 no.4
• /
• pp.281-285
• /
• 2007

Cold environments, including polar and alpine regions, are colonized by a wide diversity of micro-organisms able to thrive at low temperatures. There is evidence of a wide range of metabolic activities in alpine cold ecosystems. Like polar microorganisms, alpine microorganisms playa key ecological role in their natural habitats for nutrient cycling, litter degradation, and many other processes. A number of studies have demonstrated the capacity of alpine microorganisms to degrade efficiently a wide range of hydrocarbons, including phenol, phenol-related compounds and petroleum hydrocarbons, and the feasibility of low-temperature bioremediation of European alpine soils by stimulating the degradation capacity of indigenous microorganisms has also been shown.

• Journal of Korean Society of Environmental Engineers
• /
• v.32 no.1
• /
• pp.79-86
• /
• 2010

Effects of operating parameters such as applied voltage, solution conductivity, ferrous ion concentration, electrode material on phenol degradation by pulsed corona discharges were investigated in laboratory scale experiments. The increase of applied voltage enhanced the phenol degradation by generating more energetic electrons. The solution conductivity inversely affected phenol removal rate in the tested ranges because the increase of conductivity decreased the electric field strength through the liquid phase. The addition of ferrous sulfate promoted the phenol degradation through the OH radical production by the Fentonlike reactions between ferrous ion and hydrogen peroxide generated by pulsed corona discharges. Catechol and hydroquinone were detected as primary intermediates of phenol degradation and the decrease of pH and the increase of conductivity were observed probably due to the generation of organic acids. Almost all of the initial phenol was disappeared and 29% of total organic corbon (TOC) was removed in the condition of 0.5 mM of ferrous sulfate after approximately 230 kJ of discharge energy transferred to the reactor.

• Bulletin of the Korean Chemical Society
• /
• v.33 no.1
• /
• pp.215-220
• /
• 2012

ZnO nanoparticles were synthesized through a facile route and were used as ozonation catalysts. With the increase of calcination temperature ($150-300^{\circ}C$), surface hydroxyl groups and catalytic efficiency of asobtained ZnO decreased remarkably, and the ZnO obtained at $150^{\circ}C$ showed the best catalytic activity. Compared with ozonation alone, the degradation efficiency of phenol increased above 50% due to the catalysis of ZnO-150. In the reaction temperatures range from $5^{\circ}C$ to $35^{\circ}C$, ZnO nanocatalyst revealed remarkable catalytic properties, and the catalytic effect of ZnO was better at lower temperature. Through the effect of tertbutanol on degradation of phenol and the catalytic properties of ZnO on degradation of nitrobenzene, it was proposed that the degradation of phenol was ascribed to the direct oxidation by ozone molecules based on solidliquid interface reaction.

• Journal of Korean Society of Environmental Engineers
• /
• v.22 no.5
• /
• pp.949-957
• /
• 2000

This study investigates the remediation of the phenol or PNP(p-Nitrophenol) contaminated soils in a slurry reactor by a pure culture, P-99. The application of a pure culture for the phenol decontamination make the degradation rate three times faster than that of the mixed activated sludge. The destruction of 300 mg/L phenol was completed in 26 hours. As 1 mg of phenol was added, 0.1457 mg of microorganism was grown in the medium. The pure culture could not utilizes PNP, one of the xenobiotics, as a growth substrate. When the bacteria was induced by phenol enrichment medium. PNP could be effectively transformed with cometabolic process. The induction of the bacteria requires 1 mg of phenol for the destruction of 0.027 mg PNP. When PNP concentration in the medium contained phenol and PNP increased. the degradation rate of phenol was decreased. The degradation rate of phenol and PNP in the slurry reactor was about two times faster than in the reactor without slurry because of higher dissolved oxygen supply in the aqueous phase and adsorption on the surface of the soil.

• Microbiology and Biotechnology Letters
• /
• v.32 no.1
• /
• pp.37-46
• /
• 2004

The analysis of enzymes associated with metabolism of phenolics by Stenotrophomonas maltophilia LK-24 was conducted. To identify metabolites of phenol and phenol compound, we investigated enzymes of S. maltophilia LK-24 associated with degradation of phenolics. We found that phenol hydrolase, catechol-2.3-dioxygenase, 2-hydroxymuconic semialdehyde dehydrogenase, 2-hydroxymuconic semialdehyde hydroxylase and acetaldehyde dehydrogenase were activated. The results showed that phenolics were gone through the meta-pathway ring cleavage. The results will contribute greatly to understand metabolic pathways of phenol and it is possible to make some assessment of the feasibility of using S. maltophilia LK-24 for the treatments of phenolic-contaminated waste streams.

• Journal of Microbiology and Biotechnology
• /
• v.8 no.4
• /
• pp.388-398
• /
• 1998

A bacterium which is resistant to both mercury and cadmium, and also capable of utilizing phenol as a carbon and energy source, was isolated from the Kumho River sediments near Kangchang Bridge, Taegu, Korea. The isolate was labeled Pseudomonas sp. KM10 and characterized. The bacteria grew in 4 mM $CdCl_2$and in $70{\mu}M$ $HgCl_2$. The bacteria efficiently removed over 90% of 1 g/l phenol within 30 h. In the presence of 1.250 g/l phenol, the growth of the microorganism was slightly retarded and the microorganism could not tolerate 1.5 g/l phenol. Curing of plasmid from the bacteria was carried out to generate a plasmidless strain. Subsequent experiments localized the genes for phenol degradation in plasmid and the genes for mercury resistance and cadmium resistance on the chromosome. Dot hybridization and Southern hybridization under low stringent conditions were performed to identify the DNA homology. These results showed significant homologies between the some sequence of the chromosome of Pseudomonas sp. KM10 and merR of Shigella flexneri R 100, and between the some sequence of the chromosome of Pseudomonas sp. KM10 and cadA of Staphylococcus aureus pI258. The mechanism of cadmium resistance was efflux, similar to that of S. aureus pI258 cadA, and the mechanism of mercury resistance was volatilization, similar to that of S. flexneri R100 mer.

• Environmental Engineering Research
• /
• v.24 no.4
• /
• pp.711-717
• /
• 2019

The application of advanced oxidation for the treatment of oil refinery wastewater under UV radiation by using nanoparticles of titanium dioxide was investigated. Synthetic wastewater prepared from phenol crystals; Power Glide SAE40 motor vehicle oil and water was used. Response surface methodology (RSM) based on the Box-Behnken design was employed to design the experimental runs, optimize and study the interaction effects of the operating parameters including catalyst concentration, run time and airflow rate to maximize the degradation of oil (SOG) and phenol. The analysis of variance and the response models developed were used to evaluate the data obtained at a 95% confidence level. The use of the RSM demonstrated the graphical relationship that exists between individual factors and their interactive effects on the response, as compared to the one factor at time approach. The obtained optimum conditions of photocatalytic degradation are the catalyst concentration of 2 g/L, the run time of 30 min and the airflow rate of 1.04 L/min. Under the optimum conditions, a 68% desirability performance was obtained, representing 81% and 66% of SOG and phenol degradability, respectively. Thus, the hydrocarbon oils were readily degradable, while the phenols were more resistant to photocatalytic degradation.

• Journal of Korean Society of Environmental Engineers
• /
• v.36 no.5
• /
• pp.311-316
• /
• 2014

Effects of operating parameters such as activated carbon dose and pH on the phenol oxidation in ozone-activated carbon hybrid process were investigated through a kinetic study. Activated carbon enhanced the self-decomposition of ozone, generating $OH{\cdot}$, thus promoting phenol degradation. The pseudo-first order rate constants of phenol degradation increased and half-life of phenol decreased with activated carbon dose. The increase of pH enhanced $OH{\cdot}$ generation through chain reactions initiated by $OH^-$, therefore increasing the phenol degradation rate. TOC removal efficiency increased about 3.2 times by adding activated carbon in ozonation process.

• Journal of Microbiology
• /
• v.40 no.1
• /
• pp.86-89
• /
• 2002

Rhodococcus sp. strain T104, which is able to grow on either biphenyl or limonene, was found to utilize phenol as sole carbon and energy sources. Furthermore, T104 was positively identified to possess three separate pathways for the degradation of limonene, phenol, and biphenyl. The fact that biphenyl and limonene induced almost the same amount of catechol 1,2-dioxygenase activity indicates that limonene can induce both upper and lower pathways for biphenyl degradation by T104.