• The Korean Journal of Ecology
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• v.17 no.2
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• pp.131-141
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• 1994

One-year-old yellow-poplar (Liriodendron tulipifera L.) and sweetgum (Liquidambar styraciflua L.) seedlings were exposed to 0.10 ${\mu}l/l\;O_3$and simulated acid rain at pH 3.0 for ten consecutive weeks. Shoot height growth (SHG), fresh weight (FWT), dry weight (DWT), apparent plastochron duration (APD) and foliar nutrient concentrations were measured. None of growth measurements, except the apparent plastochron duration (APD), were significantly affected by any treatment in yellow-poplar seedlings. APD was approximately 30% higher in seedlings exposed to $0.1{\mu}l/l\;O_3$ ＋ pH 5.6 solution than any other treatment. Ozone significantly reduced SHG of sweetgum seedlings by 24% at the end of the ten-week fumigation. There were also significant effects of single and combined effects of ozone and simulated acid rain on APD in sweetgum. APD was significantly increased by 19.8% and 25.7% in seedlings exposed to $0.1{\mu}l/l\;O_3$ and pH 5.6 solution, respectively, and resulted in 46.1% higher APD in seedlings exposed to $0.1{\mu}l/l\;O_3$ + pH 5.6 solution compared with seedlings exposed to $0.0{\mu}l/l\;O_3$ ＋ pH 3.0 solution. Phosphorus and sulphur were significantly greater in seedlings exposed to simulated rain at pH 3.0 compared with pH 5.6 for both species. Foliar S concentration was higher in seedlings exposed to $0.0{\mu}l/l\;O_3$ ＋ pH 3.0 than in seedlings exposed to any other treatment in sweetgum. Ozone significantly increased Ca in sweetgum seedlings, however, ozone reduced Ca in yellow-poplar. Ozone also reduced S and Mg in sweetgum seedlings.

• Journal of Korean Society on Water Environment
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• v.20 no.2
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• pp.126-131
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• 2004

This research sought to compare chlorine, chlorine dioxide and ozone as chemical disinfectants of drinking water, with inactivation of total coliform as the indicator. The inactivation of total coliform was tested against several variables, including the dose of disinfectant, contact time, pH, temperature and DOC. A series of batch processes were performed on water samples taken from the outlet of a settling basin in a conventional surface water treatment system that is provided with the raw water drawn from the mid-stream of the Han River. Injection of 1 mg/L of chlorine, chlorine dioxide and ozone resulted in nearly 2.4, 3.0 and 3.9 log inactivation, respectively, of total coliform at 5 min. To achieve 99.9 % the inactivation, the disinfectants were required in concentrations of 1.70, 1.00 and 0.60 mg/L for chlorine, chlorine dioxide and ozone, respectively. Bactericidal effects generally decreased as pH increased in the range of pH 6 to 9. The influence of pH change on the killing effect of chlorine dioxide was not strong, but that on ozone and free chlorine was sensitive. The activation energies of chlorine, chlorine dioxide and ozone were 36,053, 29,822 and 24,906 J/mol for coliforms with inactivation effects being shown in the lowest orders of these.

• Textile Coloration and Finishing
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• v.30 no.1
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• pp.51-61
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• 2018

In this study, effluent water was produced through Submerged Membrane Bio-Reactor(SMBR) process, which is a simple system and decomposes organic matter contained in wastewater with biological treatment process and performs solid-liquid separation, Especially, ozone oxidation treatment process is applied to effluent water containing fluorescent whitening agent, which is a trace pollutant which is not removed by biological treatment, and influences the quality of reused water. The concentration of $COD_{Cr}$ in the SMBR was $449.3mg/{\ell}-COD_{Cr}$, and the concentration of permeate water was $100.3mg/{\ell}-COD_{Cr}$. The removal efficiency was about 70.1%. The amount of ozone required for the removal of the fluorescent whitening agent in the permeated water in SMBR was $6.67g-O_3/min$, and the amount of ozone required to remove $COD_{Mn}$ relative to the permeate water was calculated to remove $0.997mg-COD_{Mn}$ for 1mg of $O_3$.

• Korean Journal of Agricultural and Forest Meteorology
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• v.12 no.3
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• pp.173-182
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• 2010

This study was conducted to investigate ozone sensitivity of physiological indicators and the difference in ozone tolerance of 8 families of Sophora japonica seedlings on the basis of the standardized physiological indicators. After ozone treatment, photosynthetic parameters, photosynthetic pigments and malondialdehyde (MDA) content, and antioxidative enzyme activities were analyzed from the leaves of S. japonica seedlings. Ozone tolerance indices among 8 families were calculated with the standardized physiological parameters. In addition, the reduction of carboxylation efficiency and apparent quantum yield were observed in the leaves of seven families, except for family No. 6 and 7, respectively. The apparent quantum yield varied from -27% to -61% of the control seedlings. Photosynthetic pigment content differed significantly among 8 families, but was not affected significantly by ozone treatment. Superoxide dismutase (SOD) activity increased from 7% to 64% after ozone exposure, and significant difference existed among 8 families. Ascorbate-peroxidase (APX) activity of 8 families increased by ozone treatment, and the activity of family No. 7 showed the highest increase (218%) in comparison to their respective control plants. On the basis of the standardized indices, family No. 6 showed the lowest tolerance by indicating higher reduction of both photosynthetic parameters and pigment content and lower increase of antioxidative enzyme activities. On the contrary, family No. 7 showed the highest tolerance as indicated by lower reduction of photosynthetic parameters, higher amounts of photosynthetic pigments, and higher enzyme activity.

• Journal of Korean Society of Forest Science
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• v.95 no.3
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• pp.323-327
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• 2006

This study was conducted to understand response of damage and tolerance to ozone between ozone tolerant and sensitive families of P. densiflora which had been selected by the based on visual injury and growth. Five individuals were selected in each group, and were exposed to 100ppb ozone for 90 days. Every 30 days after ozone fumigation, diamter at root collar (ORC), superoxide dismutase (SOD) activity, and malondialdehyde (MDA) content were measured. In early state of ozone fumigation tolerant families showed three times higher relative DRC growth rate than sensitive families. And during whole fumigation period growth rate of tolerant families was superior to growth rate of sensitive families. SOD activity in sensitive families was increased 30 days after fumigation, and in accordance with fumigation period extended it was decreased continuously. MDA content in ozone treatment showed higher than in control, and MDA content of tolerant families was higher than that sensitive families. In our results tolerant families has higher antioxidative activity than sensitive families. Therefore tolerant families can restrain lipid peroxidation and damage on physiological activity.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 1999.04a
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• pp.42.1-42
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• 1999

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.47 no.1
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• pp.1-9
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• 2015

Wood fibers for medium density fiberboard (MDF) was used in the filler layer of the white duplex board for increasing thickness and bulk of the board. The MDF fibers were treated with ozone (3% based on dry weight of the fibers), and mixed together with OCC (old corrugated container) to form paper. Ozone-treated MDF fibers gave high bulk, high tensile strength, high internal bond and fast drainage to the furnish mixed with OCC. It was shown that there were possibilities to reduced basis weight of the filler layer without loss of thickness, stiffness, and tensile strength. Furthermore, it showed the possibility to develop a new kind of board product that has high stiffness as well as high strength properties with light basis weight by application of the ozone-treated MDF fibers.

• Korean Journal of Food Science and Technology
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• v.29 no.4
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• pp.764-770
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• 1997

For the purpose of improving hygienic quality of dried-spirullina and dried-sea tangle powders as raw materials of health food, the comparative effects of ozone treatment and gamma irradiation on the microbial and physicochemical properties were investigated. Gamma irradiation at 7.5 kGy resulted in sterilization of total aerobic bacteria, coliforms and molds below detective levels $(<10^{1}\;CFU/g\;sample)$, while ozone treatment for 8 hr up to 18 ppm could not sufficiently eliminate the microorganisms of the samples. Physicochemical properties including compositions of fatty acid and amino acid, minerals, pH and natural pigments were not changed by gamma irradaition up to 10 kGy, whereas, ozone treatment caused changes in pH, TBA value, natural pigments and fatty acid compositions. Especially, ozone treatment markedly decreased unsaturated fatty acid of the samples.

• Journal of Korean Society for Atmospheric Environment
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• v.28 no.1
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• pp.12-21
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• 2012

The purpose of this study is to understand distribution of ozone concentration in the south coastal region of Korea by evaluating ozone spatial distribution in the upper air using aircraft. Sampling was carried out from May to August in 2009. The average concentration of ozone in the upper air was ranged from 32.3~90.8 ppb with its maximum concentration of 132 ppb. When it comes to the spatial distribution of ozone, ambient concentration was high in the air, 1,000 m and 500 m above the southern sea near the Gwangyang Bay area and emission sources, respectively. Daily mean concentration of NOy was 6.7~24.2 ppb and that of CO was 0.152~0.487 ppm. In addition, the concentration was appeared to be relatively high in the upper air of industrial regions and the southern seas. Meanwhile, the concentration of both $NO_y$ and CO was high in the upper air of the emission sources regardless of latitude. As for PAN, its daily mean concentration ranged between 0.1 and 0.6 ppb with overall mean concentration of 0.2 ppb. The average concentration of VOCs was 48 ppb, and the concentration of toluene and m,p-Xylene were higher than other components.

• Journal of Korea Soil Environment Society
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• v.5 no.3
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• pp.3-15
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• 2001

The ozone kinetics including ozone auto-decomposition. effect of pH, and solubility were investigated. Diesel decomposition process including TCE & PCE decomposition. effect of hydroxyl radical scavenger, effect of pH, and ozone/$H_2O$$_2$by ozonation process were also examined using deionized water, simulated groundwater. and actual groundwater. Reactions with deionized water and groundwater both stowed the second-order reaction rates, and the reaction rate was much higher in groundwater (half-life of 14.7 min) than in deionized water (hal(half-life of 37.5 min). The reaction rate was accelerated at high pH values in both waters. The use of ozone showed high oxidation rates of TCE. PCE and diesel. Though hydroxyl radical scavengers existing in groundwater were inhibitors for treating diesel, high pH condition and addition of hydrogen peroxide could accelerate to degrade diesel in groundwater, indicating ozone oxidation process could be applied to treating diesel contaminated-groundwater.