• Journal of Korean Society of Environmental Engineers
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• v.29 no.7
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• pp.826-832
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• 2007

Unpleasant tastes and odors in drinking water cause same problems for water utilities across Korea. Even though tastes and odors do not create health problems, they are main concerns for consumers who determine the safety of their drinking water. In this study, two different odor producing compounds(geosmin 2-MIB) in the Nakdong river water and rapid sand filtered rater were treated by advanced oxidation of $O_3/H_2O_2$ process. The experimental results showed that the removal efficiency of geosmin with the use of 5 mg/L of $O_3$ and $H_2O_2$ was higher than efficiency with the use of $O_3$ alone for both the raw water and the sand filtered water. And in general, the removal efficiency of geosmin was higher than 2-MIB in the sand filtered water. Under the range of $O_3$ concentration $0.5\sim2.0$ mg/L, the removal rate constants(k) of geosmin for the raw and sand filtered waters, and the one of 2-MIB in the sand filtered water were increased rapidly as doses of $O_3$, and $H_2O_2$, increased. The removal rate constants(k) do not increase any more when $H_2O_2/O_3$ ratio increases above the optimum ratio. The optimum ratio of $H_2O_2/O_3$, dose was $1.0\sim2.0$ for both geosmin and 2-MIB. The removal rate constant(k) becomes lower when OH radical consuming materials are present in raw water. The half-life of geosmin decreased rapidly as the $O_3$ and $H_2O_2$ doses increase in the sand filtered water. The half life decreased about 8.5 times with the use of 2 mg/L of $O_3$ and 10 mg/L of $H_2O_2$ than with the use of 2 mg/L of $O_3$ alone for the sand filtered water.

• Journal of Korean Society on Water Environment
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• v.29 no.1
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• pp.74-80
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• 2013

The aim of this study is to evaluate color removal from leather-dyeing wastewater using $O_3$ and $O_3/H_2O_2$ unit processes and a serial process for $O_3$, followed by the $O_3/H_2O_2$ process. The color removal rate of the $O_3$ alone process was only 65% effective, and the color increased when an applied $O_3$ dose of more than 40 ~ 50 mg/L was applied. On the other hand, the color was completely removed without increments of color by the $O_3/H_2O_2$ process with $H_2O_2$ injection ratio of 0.2 and 0.3 (wt. $H_2O_2$/wt. $O_3$). Even though the injection of $H_2O_2$ had an effect on color removal, the color removal rates from $O_3$ alone and from $O_3/H_2O_2$ were similar up to the initial $O_3$-demand stage with an application of 0 ~ 40 mg/L $O_3$. In conclusion, it was found that the $O_3$ followed by the $O_3/H_2O_2$ serial process, the method injecting $H_2O_2$ after ozonation with $O_3$-demand (30 ~ 40 mg/L) in the first stage, is the most appropriate process for effective color removal from leather-dyeing wastewater.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.12
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• pp.1323-1330
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• 2006

In this study, five different odor causing compounds in the Nakdong river and rapid sand filtered waters were treated by oxidation from $O_3/H_2O_2$ process. In addition, the change in BDOC formation by the $O_3/H_2O_2$ process was also investigated for considering this advanced oxidation Process as a pre-treatment to the BAC treatment process. The experimental result showed that the removal efficiency of geosmin was higher with the use of 5 mg/L of $O_3$ and 0.2 mg/L of $H_2O_2$ than with the use of 20 mg/L of $O_3$ alone for the sand filtered water. And in general, the removal efficiency of geosmin in raw water was $12{\sim}27%$ lower than the one in sand filtered water. In sand filtered water. the removal efficiencies of geosmin and IPMP decreased when $H_2O_2/O_3$ ratio increases above the optimum ratio. The optimum ratio of $H_2O_2/O_3$ dose was $0.5{\sim}1.0$ for geosmin and $0.2{\sim}1.0$ for IPMP. However, the optimum ratio of $H_2O_2/O_3$ in raw water remove geosmin appealed to $1.0{\sim}3.0$. According to the experimental results for the removal of 5 different odor causing compounds under varied $O_3$ doses, the removal efficiency of IPMP was the highest with 60% and, in overall, $O_3/H_2O_2$ process showed higher removal efficiency than $O_3$ alone process. The BDOC formation by the $O_3/H_2O_2$ process increased from $0.1{\sim}0.25$ to $0.19{\sim}0.34$ comparing to $O_3$ process alone. Therefore, it is concluded that the advanced oxidation process with $O_3/H_2O_2$ can be used as a pretreatment to the BAC treatment process.

• JOURNAL OF ELECTRICAL WORLD
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• s.254
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• pp.53-61
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• 1998

오존은, 그 강력한 산화력에 의하여 살균, 탈취, 탈색과 유기물 제거 등의 효과를 복합적으로 얻을 수 있고 또한 신속하게 산소로 분해되어 잔류하지 않기 때문에 환경개선에 사용하기에 이상적인 물질이다. 미쓰비시전기에서는 이러한 오존의 이점에 착안하여 1970년부터 오존발생기와 오존처리설비의 개발, 제품화를 추진하여 왔다. 오존에 의한 고도처리가 널리 일반에게 인정되어 그 수요가 높아지고 있는 오늘날에 있어서도 보다 많은 오존설비의 보급을 위하여 오존기술의 개발에 힘쓰고있다. 본고에서는 상하수도 오존고도처리의 기술동향의 일부로 시도되고 있는 다음의 세 가지 내용을 소개한다. (1)오존처리시스템의 자에너지, 고효율화 기술 방전갭의 단축화, 관분내압력의 고압화로 고농도$\cdot$고효율의 오존발생을 실현하여 자전력화를 가능케 한 신형오조나이저를 개발 제품화하였다. (2)오존 반응조 내에서의 산기장치특성의 파악 모델화가 곤란한 신기장치에 대하여 실설비규모의 실험설비를 사용하여 그 산기특성을 분명히 하였다. (3)과산화수소첨가 오존처리법에 의한 하수처리수의 재생이용 과산화수소첨가 오존처리법에 의하여 장기간에 걸쳐 하수처리수를 전유기탄소(TOC)3mg/$\ell$이하로까지의 처리를 달성하여 하수처리수를 수도수레벨로까지 고도로 정화할 수 있음을 실증하였다.

• Applied Chemistry for Engineering
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• v.26 no.4
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• pp.463-469
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• 2015

Bisphenol A (BPA) in aqueous solution was measured using HPLC technique, which was established by acetonitrile analysis and KDP solution analysis methods. In these experiments the decomposition characteristics of BPA were compared using the ozone alone, ozone/pH 10, and ozone/hydrogen peroxide processes. About 70% of 10 mg/L of BPA was removed during 60 min by the ozone alone process, while 10 mg/L of BPA was completely removed by the ozone/pH 10 and ozone/hydrogen peroxide processes in 40 min and 60 min, respectively. The final decomposition efficiency drawn from results of TOC and HPLC analyses showed that the ozone/hydrogen peroxide process was the best among them, whereas the concentrations of TOC and reaction intermediates when using the ozone/pH 10 process were higher than those of the ozone alone process after 60 min of reaction. The ozone/hydrogen peroxide process was the most efficient among them when oxidizing organic carbons in water to $CO_2$ and $H_2O$.

• Journal of Animal Environmental Science
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• v.15 no.3
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• pp.209-216
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• 2009

The aim of this study was to investigate the removal effects of the color, nutritive salts and other pollutants on piggery slurry by advanced oxidation process (AOP) system. The experimental AOP system was designed to treat 300 L of piggery slurry per hour. To enhance oxidizing power of the experimental APO system, a ultraviolet irradiation system and the ultrasonic system were attached to the AOP system. With 5 min ultrasonic treatment, COD, SS and T-N concentrations were changed from 210, 820, and 309 to 200, 760, and 262 mg/L, respectively. With 10 min ultrasonic treatment, SS and T-N concentrations tended to decrease but T-P concentration was not changed. With the treatment of both ozone and ultrasonic waves for 30 min, COD, SS, T-N and T-P decreased from 238, 900, 400, and 5 to 165, 540, 263, and 4 mg/L, respectively. With the treatment of both ozone and ultraviolet irradiation for 30 min, COD, SS, T-N and T-P decreased from 321, 340, 204, and 15 to 151, 140, 111, and 7 mg/L, respectively, and color was changed from 4,344 to 624.

• Journal of Korean Society on Water Environment
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• v.28 no.5
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• pp.704-716
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• 2012

This paper provides a detailed account of pilot testing conducted at South Lake Tahoe (California), the Ddukdo (Seoul) water treatment plant (WTP) and the Bokjung (Seongnam) WTP between February, 2010, and February, 2012. The objectives were first, to characterize the reactions of ozone with hydrogen peroxide (Peroxone) for Han River water following sand filtration, second to determine empirical ozone and hydrogen peroxide doses to remove a taste-and-odor surrogate 2-methylisoborneol (MIB) using an advanced oxidation process (AOP) configuration and third, to determine the optimum dosing configuration to reduce residual ozone to a safe level at the exit of the process. The testing was performed in a real-time plant environment at both low- and high seasonal water temperatures. Experimental results including ozone decomposition rates were dependent on temperature and pH, consistent with data reported by other researchers. MIB in post-sand-filtration water was spiked to 40-50 ng/L, and in all cases, it was reduced to below the specified target level (7 ng/liter) and typically non-detect (ND). It was demonstrated that Peroxone could achieve both MIB removal and low effluent ozone residual at ozone+hydrogen peroxide doses less than those for ozone alone. An empirical predictive model, suitable for use by design engineers and operating personnel and for incorporation in plant control systems was developed. Due to a significant reduction in the ozone reaction/decomposition at low winter temperatures, results demonstrate the hydrogen peroxide can be "pre-conditioned" in order to increase initial reaction rates and achieve lower ozone residuals. Results also indicate the method, location and composition of hydrogen peroxide injection is critical to successful implementation of Peroxone without using excessive chemicals or degrading performance.

• Journal of Soil and Groundwater Environment
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• v.6 no.1
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• pp.3-12
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• 2001

During ozonation process, the hydroxyl radical generation rates were measured under different experimental conditions (ozone feed rate, nitrobenzene concentration, hydroxyl radical scavenger, pH, HO$_2$O$_2$/O$_3$ etc.) Nitrobenzene could be decomposed by hydroxyl radical rather than ozone only and nitrobenzene decomposition rate was expressed with functions of ozone and nitrobenzene concentration. The rate was decreased as the hydroxyl radical scavenger concentration was increased, and all results were followed pseudo first-order reaction. Using a competitive method, hydroxyl radical generation rate was measured with probe compound and scavenger. It was proportional to ozone concentration, and 0.24mo1 of hydroxyl radical was produced with 1mol of ozone. Under different pH conditions, hydroxyl radical generation rates were measured (pH 10.2 (0.91Ms$^{-1}$ ) > pH 7.3 (0.72Ms$^{-1}$ ) > pH 5.6 (0.67Ms$^{-1}$ ) > pH 3.4 (0.63Ms$^{-1}$ )) showing higher generation rate at high pH values. Addition of hydrogen peroxide promoted the generation rate of hydroxyl radical. Considering the results of pH experiments and addition of hydrogen peroxide experiments, the hydroxyl radical generation rate was 1.6 times higher in hydrogen peroxide solution than in high pH solution, indicating addition of hydrogen peroxide is better promoter to produce the hydroxyl radical in ozonation. These results could be applied to AOPs to remediate the contaminated wastewater and groundwater.

• Analytical Science and Technology
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• v.13 no.5
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• pp.659-665
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• 2000

The changes in $UV_{254}$ and concentrations of $H_2O_2$ formed by ozonation of aqueous humic acid in ozone/high pH, peroxone process and in the presence of radical scavenger, $HCO_3{^-}$ were investigated. This study confirmed that the formation of $H_2O_2$ by ozonation may undergo different reaction pathways compared to those of $UV_{254}$ reduction in the degradation of the humic acid. The concentration of $H_2O_2$ produced by ozonation was found to be increased with decreasing pH of the sample solution due to the higher stability of ozone molecules at acidic conditions. On the while, $UV_{254}$ reduction was found to be higher at alkaline conditions or larger amount of $H_2O_2$ additions as a radical promoter in which the producing of ${\cdot}OH$, ${\cdot}HO_2$ radicals can be more favorable. From the results, it has been suggested that the formation of $H_2O_2$ by ozonation depends mainly on the direct reactions of ozone with humic acid molecules, while $UV_{254}$ reduction is affected by both the indirect reactions of the radicals and direct reactions of ozone with humic acid.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2002.11a
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• pp.237-238
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• 2002

과산화수소는 광화학적 이차 생성물질이며 대기의 산화상태를 알려주는 지시자의 역할을 한다. H2O2 는 O3의 광분해로 시작되는 광화학 반응 중 HO2 radical 의 self reaction(HO2＋ HO2＋M$\longrightarrow$H2O2＋M)으로 주로 생성된다(Lee,2000). 대기 내 수명이 1-2일인 과산화수소를 측정하므로써 오존의 대표적인 전구물질인 NOx와 VOC를 산화시키는 OH, HO2 라디칼의 농도를 예측할 수 있고 궁극적으로 오존을 저감하는 대책을 세우는데 필요한 요인으로 사용된다. (중략)