• 한국식품저장유통학회지
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• 제3권2호
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• pp.149-154
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• 1996

In order to develovpment of new sterilizing method applied to food industry, effects of ozone treatment on microorganisms, associated with food hygiene were investigated. Microorganisms were immersed in water and sparged with ozonised air(ozone concentration, 3mg liter-1) at an air flow rate of 5 liter min-1. When organisms were treated with benzoic acid and sorbic acid of 0.4∼1.0g/$\ell$, respectively, they were not dectable perfectly. Sodium benzoate had an effect on Penicillium islandicum. When bacteria were sparged with ozonised air, Pseudomonas aeruginosa completely inhibited at 60 minutes, and the killing Aspergillus flavus and Penicillium islandicum. Also, all of bacteria were inactivated after immersed with ozonated water for 10minutes, but two fungal species were not effective.

• 한국대기환경학회지
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• 제9권4호
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• pp.278-287
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• 1993

In order to calssify smog type durnig the summer season in Seoul, air Quality and meterorological data were analyzed by multivariate analysis. Among 15 variables relating to visibility, 10 variables were selected by multiple regression analysis for clustering of smog types; total suspended particle, sulfur dioxide, ozone, ntrogen dioxide, total hydrocarbon, south-north wind component, ralative humidity, precipitable water, mixing height and air temperature. Somg types were grouped into three clusters using cubic clustering criterion and the mumbers of days in each cluster were contained 74, 28 and 16 days. Each cluster was seperated clearly by sulfur dioxide, precipitable water and air teperature. The first cluster was representative of high ozone concentration and prevailing meterological conditions for ozone formation. Therefore, visibility in the first cluster was considered to be affected by photochemical smog. The third cluster showed characteristics of sulphurous smog type due to the higher concentration of primary pollutant, based on the dry condition than that in another cluster. On the other hand, the characteristic of the second cluster was not relatively clear, but considered to be in an intermediate characteristic between photochemical smog and sulphurous smog type.

• Korean Chemical Engineering Research
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• 제45권2호
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• pp.203-207
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• 2007

불산과 오존 세정 시 실리콘 웨이퍼 표면의 미세입자를 효과적으로 제거할 수 있는 세정 방법에 대하여 연구하였다. 불산의 농도가 0.3 vol% 이상이 되어야 미세입자가 제거 되었으며, 초음파가 인가된 오존수를 사용 시 제거 효율은 증가되었다. 오존과 불산 세정 단계 이후에 추가로 극미량의(0.01 vol%) 희석 암모니아수 세정을 하면 미세입자가 99%이상 제거됨을 확인하였다. 이는 암모니아수에 의한 웨이퍼 표면의 미세 에칭 효과와 알칼리 영역에서의 재흡착 방지 효과가 동시에 작용함에 기인된다고 보인다. 한편, 불산-오존-희석 암모니아수 세정은 통상의 SC-1 세정과 비교할 때 표면 미세 거칠기가 개선되는 경향을 보였다. 불산-오존-희석 암모니아수 세정은 상온에서도 미세입자를 효과적으로 제거할 수 있는 세정 방법으로, 고온 공정 및 과다한 화학액을 사용하는 기존 습식세정의 대안으로서 기대된다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.2
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• pp.795-798
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• 2003

Toxic organics are of great environmental concern primarily because they are toxic to mammals and birds, and are relatively soluble in water to contaminate surface water and groundwater. In this study, the decomposition of phenol, a widely used organic, in aqueous solutions by Boron doped diamond(BDD) electrode was examined. 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. Decomposition of phenol concentration in the reaction solution by photolytic ozonation( $UV/O_3$) was analyzed by HPLC epuipped with a UV detector.

• 상하수도학회지
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• 제19권6호
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• pp.767-774
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• 2005

The DOF (Dissolved Ozone Flotation) system was used to treat the effluent of the secondary wastewater treatment plant. The DOF system uses ozone instead of air, while DAF (Dissolved Air Flotation) uses air. Moreover, since the solubility of ozone is higher than air, the DOF system produces larger volume of micro-bubbles than the DAF system does. Thus, the DOF system performs better than the DAF system in floating ability. The DOF system could remove 70% of turbidity to an average of 0.59NTU in effluent from 2.31NTU in influent. The removal efficiency of absorbance measured with UV-254 in the effluent of the DOF system was 63%, while only 19% was removed by the DAF system. the DOF system removed 84% of the color from 25~26CU to 4CU, while DAF system removed 42% of the color to 15 CU. The CODMn removal efficiency of the DOF system was 34%, 6.8mg/l of effluent $COD_{Mn}$ concentratin, while it was 20%, 8.3mg/L of effluent $COD_{Mn}$ concentratin, to use the DAF system. Microbial bacteria such as coliform bacteria, and heterotrophic bacteria were removed over 99% by the DOF system, and 42~45% by the DAF system. That is, Microbial bacteria were almost completely destroyed by the DOF system. To sum up with, the DOF system was found to be very effective to treat effluent of the wastewater treatment plant.

• 한국환경보건학회지
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• 제32권2호
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• pp.171-178
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• 2006

The objectives of this study were to investigate the formation of trihalomethanes(THMs) and to compare the concentration level of THMs of swimming pools water by different disinfection methods such as chlorine, ozone-chlorine, and salt brine electrolysis generator (SBEG). The concentration of chloroform was the highest in the chlorine system, and the SBEG was the highest in the production of bromodichloromethane (BDCM), dibromochloromethane (DBCM) and bromoform. The average concentration of total trihalomethanes (TTHMs) in three disinfection systems were $64.5{\pm}27.4mg/l(SBEG),\;43.8{\pm}22.3mg/l(chlorine)$, and $30.6{\pm}16.1mg/l(ozone-chlorine)$, respectively. In chlorine and ozone-chlorine disinfection system, chloroform concentration was highest, followed by BDCN, then DBCM. In the SBEG, TTHMs was composed of 42% of chloroform, 28.9% of bromoform, 15.1% of BDCM and 14% of DBCM, respectively. The strongest correlation was obtained in the levels of chloroform and TTHMs in chlorine, and ozone-chlorine disinfection systems from both indoor and outdoor swimming pools ($r=0.989{\sim}0.999$, p<0.01). In the SBEG, the levels of BDCM and TTHMs showed a good correlation (r=0.913, p<0.01). In chlorine and ozone-chlorine disinfection systems at indoor swimming pools, pH, TOC and $KMnO_4$ consumption showed strong correlation with chloroform and TTHMs concentrations (p<0.01). In the SBEG, pH and TOC were also strongly correlated with chloroform (p<0.01). pH and TTHMs were correlated as well (p<0.05).

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2002년도 학술.기술논문발표회
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• pp.59-62
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• 2002

Recently, advanced system for water and wastewater treatment is introduced and operated because of water pollution and etc. One of this System makes use of O3(Ozone) for water and wastewater treatment. In airtight concrete structure, waterproofing phase as well as water are affected by strong oxidative O3 in the long-term. For this reason, material stability against O3 is examined. Consequently, the purpose of this study is to find out material stability an object of epoxy resin by way of accelerated O3 testing.

• 환경위생공학
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• 제12권2호
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• pp.43-49
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• 1997

Iron and manganese problems in ground water affect far more water systems than almost any other water quality concern. The purpose of this study is to find the optimum condition of ozonation for the removal of dissolved iron, manganese and other organics in the polluted ground water. We proposed 4mg/l, 8mg/l as optimum ozone dose for the removal of $Fe^{2+},{\;}Mn^{2+}$, respectively. The removal efficiencies of $COD_{Mn}$ and $COD_{Cr}$ in ozone dose of 2mg/l - 6mg/l were about 40-50%. The removal efficiency of $NH_{3}-N$ was about 30-40% at pH8.5. In conclusion, it needs further systematic study and research concerned to treatability of $Fe^{2+},{\;}Mn^{2+}$ and biodegradability of organic compounds using Ozonation followed by biological filtration process in ground water treatment train.

• 대한방사선치료학회지
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• 제21권2호
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• pp.75-82
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• 2009

목 적: 방사선 치료 시 치료실 내에서 발생하는 오존량을 측정하여 오존 발생으로 인한 오염 정도를 알아보고자 한다. 대상 및 방법: 선형가속기(Clinac 21EX, Varian, USA)와 오존 측정기(series-200, aeroQual, New Zealand)를 이용하여 water phantom (Wellhofer, IBA, Germany)에 방사선을 조사하여 MU, 선량율, 선원-표면간 거리(SSD), 조사야, 에너지, 경과 시간에 따라 발생되는 오존량을 측정 분석하였으며, 실제 환자치료 시 치료실 내에 오존 측정기를 위치하여 일일 오존 변화량을 측정하였다. 결 과: 방사선 발생 중 생성되는 오존의 오염도는 에너지에 따른 영향을 크게 받지 않지만 대체로 광자선보다 전자선 조사 시(0.016~0.028 ppm/hr) 많이 발생하였다. 또한, Dose-Rate가 높을수록(0.016~0.025 ppm/hr), SSD가 멀어지고(0.018~0.030 ppm/hr), 조사야가 넓어지고(0.016~0.025 ppm/hr), MU가 많을수록(0.018~0.046 ppm/hr) 오존 농도가 높아졌다. 시간 경과에 따른 오존의 감소량은 방사선을 조사한 후 10분이 경과된 후부터 background 농도(0.016 ppm/hr)로 변화하였다. 그리고 방사선 치료실 내의 일일 발생하는 오존의 농도는 실내의 오존 허용기준인 0.1 ppm/hr (측정 평균 0.06 ppm/8 hr) 이하이지만, 냄새에 민감한 환자들이 감지할 수 있는 수준인 0.02 ppm/hr 이상의 농도(최대: 0.038 ppm/hr)를 포함하는 것을 확인할 수 있었다. 결 론: 일정한 조건의 변화에 따른 오존 농도를 통하여 실제 치료실 내 오존 발생량은 환자나 작업종사자에 대해 유해한 작용을 미치는 수준은 아니었다. 흔히 오존을 해로운 기체라고 생각하지만 방사선 치료 시 발생되는 미량의 치료실 내 오존은 오히려 병원성 세균이나 바이러스 살균 등의 공기 정화 작용을 함으로써 치료실 내 이로운 오존의 역할을 할 것이라 사료된다.

• 한국물환경학회지
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• 제24권6호
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• pp.682-689
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• 2008

The purpose of this study was to find out the variation between molecular size distribution (MSD) of natural organic matter (NOM) in raw waters after different water treatment processes like conventional process (coagulation, flocculation, filtration) followed by advanced oxidation process (ozonation, GAC adsorption). The MSD of NOM of Suji pilot plant were determined by Liquid Chromatography-Organic Carbon Detection (LC-OCD) which is a kine of high-performance size-exclusion chromatography (HPSEC) with nondispersive infrared (NDIR) detector and $UV_{254}$ detector. Five distinct fractions were generally separated from water samples with the Toyopearl HW-50S column, using 28 mmol phosphate buffer at pH 6.58 as an eluent. Large and intermediate humic fractions were the most dominant fractions in surface water. High molecular weight (HMW) matter was clearly easier to remove in coagulation and clarification than low molecular weight (LMW) matter. Water treatment processes removed the two largest fractions almost completely shifting the MSD towards smaller molecular size in DW. No more distinct variation of MSD was observed by ozone process after sand filtration but the SUVA value were obviously reduced during increase of the ozone doses. UVD results and HS-Diagram demonstrate that ozone induce not the variation of molecular size of humic substance but change the bond structure from aromatic rings or double bonds to single bond. Granular activated carbon (GAC) filtration removed 8~9% of organic compounds and showed better adsorption property for small MSD than large one.