• Bulletin of the Korean Chemical Society
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• 제25권12호
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• pp.1907-1910
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• 2004

Generation of hydroxyl radical, one of their major active species in ozonation of water was directly observed with spin-trapping/electron spin resonance (ESR) technique using 5,5-dimethyl-pyrrolidine-1-oxyl (DMPO) as a spin-trapping reagent. Hydroxyl radical was trapped with DMPO as a stable radical, DMPO-OH. 80 mM of ozone produced $1.08{\times}10^{-6}$M of DMPO-OH, indicating that 1.4% of ${\cdot}$OH is trapped with DMPO if ${\cdot}$OH is produced stoichiometrically from ozone. Humic acid suppressed DMPO-OH generation in a dose-dependent manner. Generation rate of DMPO-OH was determined with ESR/stopped-flow measurement. Phenol derivatives increased the amount and generation rate of DMPO-OH, indicating that phenol derivatives enhance·OH generation during ozonation of water.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 추계학술대회 논문집 전기물성,응용부문
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• pp.170-172
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• 2002

Thin, Boron-doped conducting diamond films are expected to be excellent electrodes for industrial electrolysis. Boron-doped diamond(BDD) were used as anode for generating ozone gas by electrolysis of acid solution. In this work, we have studied ozone generating system using BDD electrode. In order to determine the ozone generation properties of diamond electrode, experimental conditions, electrolyte concentration, temperature, flow rate and reaction time were varied diversely. As a result, we could confirm that ozone gas was generated successfully and the performance of diamond electrode was stable for electrolyte while $PbO_2$ electrode was disintegrated. Actually we are found that ozone amount increased by lowering the temperature of electrolyte.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 C
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• pp.2214-2216
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• 2005

This paper is researched discharge and ozone generation characteristics of ozonizer using $Al_2O_3$ Ceramic dielectric. The discharge characteristics with variation of the discharge electrode area is studied. The characteristics of ozone concentration. ozone generation and ozone yield were measured to discharge power, discharge electrode area and supplied gas flux for oxygen and air. The solubility of ozone for water concentrations and ozone generations proportional to discharge power and discharge electrode area. Ozone yield has slowly increase with Increasing discharge power at high flow-rate. As the result, the maximum values of ozone characteristics ozone generation and ozone yield, can be obtained 5817[ppm] and 36[g/kWh]. We make enough the ozone concentration as the air in the home. An electric discharge electrode area is apt to shrink gradually into a miniaturization trend of the ozonizer but the enlargement of the occurrence flight of the electric discharge area gives the characteristic enhance the aid in the identity condition through the structure improvement.

• 상하수도학회지
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• 제33권4호
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• pp.243-250
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• 2019

This objective of this study was to investigate the degradation characteristics of phenol, a refractory substance, by using a submerged dielectric barrier discharge (DBD) plasma reactor. To indirectly determine the concentration of active species produced in the DBD plasma, the dissolved ozone was measured. To investigate the phenol degradation characteristics, the phenol and chemical oxygen demand (COD) concentrations were evaluated based on pH and the discharge power. The dissolved ozone was measured based on the air flow rate and power discharged. The highest dissolved ozone concentration was recorded when the injected air flow rate was 5 L/min. At a discharge power of 40W as compared to 70W, the dissolved ozone was approximately 2.7 - 6.5 times higher. In regards to phenol degradation, the final degradation rate was highest at about 74.06%, when the initial pH was 10. At a discharged power of 40W, the rate of phenol decomposition was observed to be approximately 1.25 times higher compared to when the discharged power was 70W. It was established that the phenol degradation reaction was a primary reaction, and when the discharge power was 40W as opposed to 70W, the reaction rate constant(k) was approximately 1.72 times higher.

• 대한전자공학회논문지SD
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• 제44권1호
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• pp.22-27
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• 2007

반도체 또는 평판디스플레이 제조에 있어 노광공정 후의 PR(photoresist) 제거 공정으로 이용하기 위하여 경계 막 제어에 의한 오존처리공정 및 설비 구현에 대한 연구를 수행하였다. 개발한 초 고농도 오존생성기술과 vapor 발생 방식 경계 막 제어 오존처리공정설비에 의해 실리콘 웨이퍼 PR 제거시험을 수행하였으며 오존가스농도 16wt%, 오존가스 유량 $8[\ell/min]$에서 약 400nm/분의 높은 PR 제거율을 달성하였다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제52권12호
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• pp.579-585
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• 2003

Recently the utilization of the ozone dissolved de-ionized water(DI-O3 water) in semiconductor wet cleaning process to replace the conventional RCA methods has been studied. In this paper, we propose the water-electrode type ozone generator which has the ozone gas characteristics of the high concentration and high purity to produce the high concentration DI-O3 water for the silicon wafer surface cleaning process. The ozone generator has the dual dielectric tube structure of silent discharge type and the water is both used to electrode and cooling water. We investigate the performance of the proposed ozone generator which has the design goal of the concentration of 7[wt%] and ozone generation quantity of 6[g/hr] at flow rate of 1[$\ell$/min). The experiment results show that the water electrode type ozone generator has the characteristics of 8.48[wt%] of concentration, 8.08[g/hr] of generation quantity and 76.2[g/kWh] of yield and it's possible to use the proposed ozone generator for the DI-O3 water cleaning process of silicon wafer surface.

• 한국지반환경공학회 논문집
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• 제11권8호
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• pp.41-47
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• 2010

본 연구에서는 휴믹산 농도, 초기 pH 그리고 공기주입유량과 같은 실험인자가 오존/페록시라디칼 반응시스템의 처리효율에 미치는 영향과 연속 처리을 통한 시스템의 처리 특성을 실험적으로 검토하였다. 오존과 페록시라디칼을 조합한 시스템의 처리효율은 각각의 단독공정에 비해 더 높은 색도 제거효율을 나타내었다. 초기 휴믹산 농도가 증가할수록 처리효율이 증가했지만 초기 휴믹산 농도 30mg/L 이상에서는 오히려 처리효율이 감소한 결과를 나타냈고 초기 pH의 경우 산성영역에서 보다는 중성과 알카리성 영역에서 휴믹산 제거효율이 더 높았으며 공기주입유량이 증가할수록 시스템의 처리효율이 증가하였다. Pilot-scale 시스템을 실제 정수장 유입수에 적용시킨 결과, TOC와 $COD_{Cr}$에 대한 각각의 평균 제거율은 약 70%와 60%로 나타나 수중 난분해성 유기물 제거를 위한 적용가능성을 확인할 수 있었다.

• 조명전기설비학회논문지
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• 제28권5호
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• pp.76-81
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• 2014

The ozone generation is commonly made with silent discharge method using quartz glass dielectric. In this paper, using $Al_2O_3$ dielectric to instead of the traditional quartz glass dielectric to improve the system efficiency is presented. The dielectric was manufactured as tube shape (Internal diameter${\times}$ Outside diameter: $11{\times}15mm$) using 99% $Al_2O_3$ ceramic. The characteristics of dielectric discharge and ozone generation were studied of experiments with variation of discharge power, discharge electrode space and rate of flow for supplied gas ($O_2$/Air). As the experimental results, in the same discharge space, the ozone concentration continuously increased with input power increasing, and ozone yield increased until saturation happened. Also, the expended power increased with discharge space extended due to discharge power increased. In additional, the ozone concentration of oxygen ozone was higher than air that was observed when using oxygen ozone in proposed experiments.

• Asian Journal of Atmospheric Environment
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• 제5권1호
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• pp.21-28
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• 2011

Occupational nanomaterial exposure is an important issue in the manufacture of such products. People are also exposed to various nanoparticles in their living environments. In this study, we investigated nanoparticle formation during the reaction of ozone and volatile organic compounds (VOCs) emitted from a commercial air freshener, one of many widely used consumer products, in a $1-m^3$ reaction chamber. The air freshener contained various VOCs, particularly terpenes. A petri dish containing 0.5 mL of the air freshener specimen was placed in the bottom of the chamber, and ozone was continuously injected into the center of the chamber at a flow rate of 4 L/min with an ozone concentration of either 50, 100 or 200 ppb. Each test was conducted over a period of about 4 h. The higher ozone concentrations produced larger secondary nanoparticles at a faster rate. The amount of ozone reacted was highly correlated with the amount of aerosol formation. Ratios of reacted ozone concentration and of formed particle mass concentration for the three injected ozone concentrations of 50, 100 and 200 ppb were similar to one other; 4.6 : 1.9 : 1.0 and 4.7 : 2.2 : 1.0 for ozone and aerosol mass, respectively.

• 한국식품위생안전성학회지
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• 제11권3호
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• pp.221-225
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• 1996

For the purpose of improving hygienic quality of health-foods, sterilization effects of ${\gamma}$-ray and ozone on microoganisms associated with food cultured in the media and contaminated in Angelica keiskei powder were investigated. Ozone was immersed in water and sprayed in air, on the concentration of 3 mg liter-1 at an air flow rate of 5 liter min-3. Test strains cultured in the media completely inhibited by ${\gamma}$-ray at irradiation doses of 0.25~2 kGy. In the case of ozone, test bacteria inactivated after treatment of 10~20 minutes, but test mold, Aspergillus flavus was not effective. Strains contaminated in Angelica keiskei powder completely inhibited by ${\gamma}$-ray at irradiation doses of 2.5~7.5 kGy. However, when the powder was sprayed with ozonized air for 10hours, Bacillus subtilis and Staphylococcus aureus among five strains were eliminated.