• 분석과학
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• 제13권5호
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• pp.652-658
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• 2000

오존 분자와의 직접반응경로 및 OH라디칼을 통한 간접반응경로를 통한 부식산의 분해특성을 TOC, $UV_{254}$ 그리고 오존 소모량의 변화를 통해 살펴보았다. 부식산의 분해를 위한 반응시스템은 오존 단독 처리 외에 OH라디칼의 생성조건을 조사하기위해 pH를 5에서 염기성 영역인 9까지 변화시켰으며, OH라디칼 생성 촉진제인 $H_2O_2$를 5-15 mg/L의 농도로, 그리고 OH라디칼 소거제로서 작용하는 $HCO_3{^-}$는 20-100 mg/L로 변화시키면서 처리하였다. 각 반응 조건에 따른 부식만의 분해특성을 살펴본 결과, TOC 제거율은 주로 0H라디칼에 의한 간접반응의 영향을 받았으며, $UV_{254}$ 감소율은 주로 오존분자와의 직접반응에 의해 효율이 결정되는 반응 경로를 거치는 것으로 나타났다. 또한 오존소모량은 주로 용액의 pH, alkalinity 변화에 따른 영향을 많이 받았다.

• 대한환경공학회지
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• 제29권6호
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• pp.662-669
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• 2007

Rhodamine B(RhB) 폐수의 색도와 COD 제거를 위해 $O_3$, $UV/TiO_2$, $O_3/UV$ 및 $O_3/UV/TiO_2$ 공정과 같은 고급산화법의 영향을 연구하였다. 오존 공정의 경우 오존 농도가 높을수록 탈색속도가 높아졌으며, $UV/TiO_2$와 $O_3/UV/TiO_2$ 공정의 최적 $TiO_2$ 농도는 0.4 g/L 였다. $O_3/UV$ 공정은 오존 공정에 비해 초기 탈색속도상수가 높고 탈색종결시간도 줄어드는 것으로 나타났다. 실험에 적용한 공정의 초기 탈색속도상수의 순서는 $O_3/UV/TiO_2>O_3/UV>O_3>UV/TiO_2$로 나타났다. 모든 공정의 탈색속도가 COD로 표시한 무기화 속도보다 빠르고, COD는 처리에 시간이 더 소요되는 것으로 나타났다. COD 제거속도는 $O_3/UV/TiO_2>O_3/UV>UV/TiO_2{\geqq}O_3$의 순서로 나타났다. 네 공정 중에서 광촉매와 오존 공정을 조합한 $O_3/UV/TiO_2$ 공정이 염료 폐수와 같은 폐수의 색도와 COD 제거에 적절한 것으로 나타났다.

• 산업기술연구
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• 제26권A호
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• pp.199-205
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• 2006

Ozone alone and catalytic ozone processes were introduced for treatment of humic acid, which is representative refractory organic compound. The treatment efficiencies of humic acid in each process were analyzed in pH variation, DOC removal, and $UV_{254}$ decrease. Mn loaded GAC catalyst was prepared by loading potassium permanganate onto the granular activated carbon surface. BCM-GAC and BCM-Silica gel catalyst were prepared by BCM. $UV_{254}$ decrease in all processes was comparatively high with efficiency over 87%. DOC removal in ozone/GAC process was the highest with 78%, and removal rates for other processes followed the order ozone/BCM-GAC(62%) > ozone/BCM-silica gel(45%) > ozone/silica gel(43%) > ozone/Mn Loaded GAC(42%) > ozone alone(37%).

• 센서학회지
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• 제25권4호
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• pp.275-279
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• 2016

Chemical vapor deposited (CVD) polycrystalline graphene is widely used for various sensor application because of its extremely large surface-to-volume ratio. The electrical properties of CVD-graphene is significantly affected by the grain size and boundaries (GGBs), but evaluation of GGB of continuous monolayer graphene is difficult. Although several evaluation methods such as tunneling electron microscopy, confocal Raman, UV/ozone-oxidation are typically used, they still have issues in evaluation efficiency and accuracy. In this paper, we suggest an improved evaluation method for precise and simple GGB evaluation which is based on UV/ozone-oxidation and chemical etching process. Using this method, we could observe clear GGBs of CVD-graphene layers grown by different process conditions and statistically evaluate average grain sizes varying from $1.69{\sim}4.43{\mu}m$. This evaluation method can be used for analyzing the correlation between the electrical properties and grain size of CVD-graphene, which is essential for the development of graphene-based sensor devices.

• 생명과학회지
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• 제9권5호
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• pp.590-595
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• 1999

The objectives of this research were to estimate variation characteristics of TOC, UV-254 and NH4+-N, etc, if odorous generated algaes flowed into water treatment plant and they contacted with ozone known as typical advanced treatment. It was estimated that pH decreased from initial 7.4 to 2.1 after ozone contact 100min. pH declined to early 10min. suddenly and then pH drop did almost occur. TOC and UV-254 continued to decrease with passed time of ozone contact. NO3--N concentration was much higher than NH4+-N and NO2--N for whole test period. Because ozone oxidized organic matters as various kinds of ion material and ion intensity of sample was extended, conductivity showed high as passed time of ozone contact. Owing to ozone oxidation of algae, color did almost disappear after ozone contact 20min.

• 상하수도학회지
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• 제10권4호
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• pp.55-63
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• 1996

This research was based on comparing ozonation with combined ozone/ultraviolet oxidation through the methods of reducing THM produced during water treatment. The results were as follows ; 1. The decline of THM concentration was appeared according as ozone dosage increases with ozonation and combined ozone/ultraviolet oxidation. The more effective method was the treatment of irradiating UV then ozonation. In the beginning of reaction the decline rate of THM formation potential was low, I thought it was because that the reaction of ozone and humic acid needed times to be steady state, or that THM formation potential existed according to humic acid. 2. The effect of combined ozone/ultraviolet oxidation when ozone dosage was 4.2mg/L min was almost the same that of ozonation when ozone dosage was 8.6mg/L min. 3. In experiment of TOC decline through ozonation and combined ozone/ultraviolet oxidation, TOC concentration was also dropped according to increasing ozone dosage and the more effective results were showed in treatment of irradiating UV than ozonation. But the similar TOC remove rates were showed in experiment of changing with ozone dosage during combined ozone/ultraviolet oxidation TOC remove rates were low in proportion to the remove rates of THM formation potential, it was considered that humic acid was made low molecule itself though ozonation and ozone/ultraviolet oxidation. Moreover, the high degree of remove efficiency will be get though the treatment of activated carbon of GAC treatment after combined ozone/ultravilet oxidation.

• 한국대기환경학회지
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• 제24권1호
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• pp.91-99
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• 2008

A multilayer tower-type photoreactor, in which $TiO_2$-coated glass-tubes were installed, was used to measure the vapor-phase BTEX removal efficiencies by ozone oxidation ($O_3$/UV), photocatalytic oxidation ($TiO_2$/UV) and the combination of ozone and photocatalytic oxidation ($O_3/TiO_2$/UV) process, respectively. The experiments were conducted under various relative humidities, temperatures, ozone concentrations, gas flow rates and BTEX concentrations. As a result, the BTEX removal efficiency and the oxidation rate by $O_3/TiO_2$/UV system were highest, compared to $O_3$/UV and $TiO_2$/UV system. The $O_3/TiO_2$/UV system accelerated the low oxidation rate of low-concentration organic compounds and removed organic compounds to a large extent in a fixed volume of reactor in a short time. Therefore, $O_3/TiO_2$/UV system as a superimposed oxidation technology was developed to efficiently and economically treat refractory VOCs. Also, this study demonstrated feasibility of a technology to scale up a photoreactor from lab-scale to pilot-scale, which uses (i) a separated light-source chamber and a light distribution system, (ii) catalyst fixing to glass-tube media, and (iii) unit connection in series and/or parallel. The experimental results from $O_3/TiO_2$/UV system showed that (i) the highest BTEX removal efficiencies were obtained under relative humidity ranging from 50 to 55% and temperature ranging from 40 to $50^{\circ}C$, and (ii) the removal efficiencies linearly increased with ozone dosage and decreased with gas flow rate. When applying Langmuir-Hinshelwood model to $TiO_2$/UV and $O_3/TiO_2$/UV system, reaction rate constant for $O_3/TiO_2$/UV system was larger than that for $TiO_2$/UV system, however, it was found that adsorption constant for $O_3/TiO_2$/UV system was smaller than that for $TiO_2$/UV system due to competitive adsorption between organics and ozone.

• 한국물환경학회지
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• 제24권1호
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• pp.63-68
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• 2008

This study was performed to assess the potential use of ozone or UV radiation for the treatment of water contaminated with sulfamethoxazole (SMX), which is frequently used antibiotic in human and veterinary medicines, especially focusing on the kinetic study and effect of pH. In a study using ozone alone, kinetic study was performed to determine second-order rate constant ($k_{O3,SMX}$) for the reactions of SMX with ozone, which was found to be $1.9{\times}10^6M^{-1}s^{-1}$ at pH 7. The removal efficiencies of SMX by ozone were decreased with increase of pH due to rapid decomposition of ozone under the condition of various pH (2.5, 5.3, 7, 8, 10). In a UV irradiation study at 254 nm, a kinetic model for direct photolysis of SMX was developed with determination of quantum yield ($0.08mol\;Einstein^{-1}$) and molar extinction coefficient ($15,872M^{-1}cm^{-1}$) values under the condition of quantum shielding due to the presence of reaction by-products formed during photolysis. For effect of pH on photolysis of SMX, SMX in the anionic state ($S^-$, pH > 5.6), most prevalent form at environmentally relevant pH values, degraded more slowly than in the neutral state (SH, 1.85 < pH < 5.6) by UV radiation at 254 nm.

• 폴리머
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• 제38권3호
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• pp.391-396
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• 2014

고분자 마이크로니들은 몰딩 공정으로 쉽고 저렴하게 생산할 수 있지만 3차원 고분자 마이크로 구조체에 수용액 기반의 약물 코팅은 어려움이 있다. 2차원 형태의 평면 금속 마이크로니들에 약물을 코팅한 기존의 코팅 마이크로니들과 비교하여 볼 때 3차원 구조의 고분자 마이크로니들은 코팅 면적이 2배 넓고 단위면적당 마이크로니들의 수를 크게 증가시킴으로써 두 배 이상의 약물을 경피를 통해 전달할 수 있다. 증점제와 계면활성제 첨가 방법의 경우 2차원의 평면에는 균일한 코팅을 얻을 수 있었지만 3차원 구조의 고분자 마이크로니들 표면에서는 만족할 코팅을 얻지 못했다. 하지만, 고분자 마이크로니들 표면을 금속 코팅 혹은 UV/ozone으로 처리한 경우 3차원의 마이크로 니들 표면에 만족할 코팅을 얻을 수 있었으나 금속 코팅의 경우 피부에 찌르고 제거하는 과정에서 금속이 피부 안에 남는 안전성 문제가 있어 UV/ozone을 최종 표면 처리 방법으로 선정하였다. 이렇게 처리한 고분자 마이크로니들 표면에 calcein이 첨가된 코팅물질로 코팅된 마이크로니들은 15분 이상의 피부 투여로 코팅물질을 성공적으로 진피층까지 전달할 수 있었다.

• 한국식품과학회지
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• 제36권2호
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• pp.255-261
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• 2004

일반적으로 탁주 생산 공정에서 오존을 처리하는 경우는 용기 및 음용수의 소독을 주목적으로 하고 있다. 그러나 지하수 등에 오존을 이용하는 경우, 오존의 산화반응으로 탁주의 품질 에 긍정적인 효과를 보이는 것으로 나타났으며 담금 공정에서의 오존처리효과를 분석한 결과, 오존 처리시 수중의 오존의 오존농도가 1 ppm이하의 규정을 유지한 상태에서 오존주입량을 증가시키게 되면 오존 증가와 함께 에탄올의 생성량은 1차 담금 4일 째부터 20%이상 증가하는 것으로 나타났다. 특히 오존을 단독으로 처리하는 경우보다 오존과 자외선을 동시에 처리하는 경우에 에탄올 생성량은 10%이상 증가하는 것으로 나타났다. 또한, 오존의 주입시간에 따라 에탄올 발생량이 다르게 나타났으며 오존주입시간을 4시간 처리한 경우가 미 오존 처리한 경우와 비교하여 수중의 경도는 85%이상 감소되며 전기전도도는 50%이상 증가하였지만 수중의 산소농도는 1.2 ppm 미만으로 큰 차이가 나타나지 않았다. 지하수의 오존주입시간별 발효일 경과에 따라 에탄올 발생량을 비교해 본 결과 담금 첫날과 비교하여 담금일 4일후 최대 300% 차이가 나는 것으로 나타났다. 이상의 실험결론을 토대로 1차 담금에서 당의 생성량을 비교해 본 결과, 오존단독 처리와 오존과 자외선을 동시에 처리한 경우와 비교하였을 경우에 당의 생성량은 35%이상 증가하는 것으로 나타났다.