• Proceedings of the Korean Environmental Sciences Society Conference
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• 2008.11a
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• pp.350-354
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• 2008

전기/UV 공정에 사용하기 위해 일반적인 살균 램프인 UV-C 램프와 오존도 같이 발생하는 오존 등의 RhB 분해능을 고찰한 결과 오존 램프의 RhB 제거율이 UV-C램프보다 높은 것으로 나타났다. 전해질을 첨가하지 않은 전기/UV 공정에서 최적 전류는 1 A로 나타났다. 전기/UV 공정에서 RhB 제거의 경우 전기분해 공정과 UV 공정의 단일 공정의 RhB 농도감소와 전기/UV 복합 공정의 RhB 제거는 같아 공정의 시너지 효과는 관찰되지 않았다. 그러나 COD의 경우 전기분해 공정과 오존 램프에 의한 단일 공정의 COD 제거보다는 전기/UV 공정의 COD 제거농도가 높아 시너지 효과가 나타나는 것으로 사료되었다.

• 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 $H_2O$.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 1997.10a
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• pp.67-67
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• 1997

정수공정은 "원수 -1 침사지 1 전염소 -1 전오존 -1 침전지 1 여과지 1 후오존 1 GAC 4 후염소 1 가정수"로 이루어져 있으며 전처리 공정으로 염 소와 오존을 주입하게 되는데, 여기서 전염소 처리 공정으로 인해 잔류 유리염 소가 수중의 유기물질과 반웅하여 유해성 유기염소 화합물 (i.e.. Trihalomethane, Haloacetonitriles, Chlorophenol 등)을 생성하는 것으로 알려져 있다. 이러한 이유로 고도 정수처리 공정에서는 강한 산화력을 지닌 대체 산화 제로서 오존을 이용하고 있다. 전오존 처리공정은 OOC와 탁도 제거에 있어 응 집제 주입량을 감소시키는 것과 더불어 전오존 효과 (산화, 생분해 증대, 살균 등)를 얻을 수 있는 것으로 알려져 왔다. 그러나 낙동강과 같이 유기물이 많은 원수에 과다한 오존이 주입되면 수중 의 유기물이 저분자화 또는 응집이 어려운 오존 산화물로 변화하여 응집제의 소비가 많아지게 된다. 실제, 오존을 응집 효과에 대해서 pilot plant로 운전한 결과 전오존에 의해 입자성 물질의 제거 효율은 향상된 반면에 유기물 제거는 뚜렷한 효과를 볼 수 없었다고 보고되었다 (류, 1997). 본 연구에서는 물금 지역의 원수와 응집-침전 공정까지 거치는 각각의 처 리수에 대해서 전처리가 응집에 미치는 영향을 천연유기물질 (NOM)의 조성 변화로 파악하였다. 그 방법으로 천연유기물질 (NOM)을 XAD-1, -4 수지를 이 용하여 소수성 물질 (hydrophobic components)과 친수성 물질 (hydrophilic components)로 분리 및 농축하여 용존 유기물이 처리 과정에서 어떻게 변화하 는지를 조사하여 개선된 상수 처리 시스템을 설계하는데 기초 자료를 제공하고 수질 관리 분야에서도 적용하고자 하였다. 상수원수인 물금 지역의 소수성 물질(hydrophobic components)은 75~80%, 친수성 물질(hydrophilic components)은 30~33%정도의 분포를 보였고, 전염소 및 전오존 공정을 거친 처리수에서는 각각 62.2-62.8%, 43.9~49.0% 및 50~ 55%, 40~57% 정도의 분포를 보였다. 그리고 웅집-침전을 거친 처리수에서는 그 분포가 77~82%, 24-48%였다. 전주리 공정을 통하여 소수성 물질(byoghobic components)의 분포가 감 소하는 것을 볼 때 전염소 및 전오존 처리가 용존유기물의 응집에는 오히려 역 효과를 나타내는 것으로 판단된다. 것으로 판단된다.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.9
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• pp.989-994
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• 2005

The treatment efficiency and the degradation characteristics of humic acid were investigated in three processes-GAC adsorption, Ozone alone and Ozone/GAC hybrid process, in which $UV_{254}$, DOC, molecular size distribution and surface change of GAC were evaluated. DOC removal rate in Ozone/GAC hybrid profess(ca. 80%) was higher than the arithmetic sum of Ozone alone(38%) and GAC adsorption(19%). This result approves that the combined Ozone/GAC hybrid process brings synergistic effects on DOC removal from the HA containing water. $UV_{254}$ decrease rate was also at the highest in Ozone/GAC hybrid process from the three processes. It may be interpreted that the granular activated carbon in Ozone/GAC hybrid process acts as not only an adsorbent but also a catalyst for ozonation, and futhermore offers an additional reaction site between adsorbed organic matter and ozone. In the study of molecular sire distribution, there was no significant change of molecular size distribution in the GAC adsorption process during the reaction time of 120 min. In Ozone alone process, the fraction of molecular size over 30 kDa was decreased a little at the beginning and left constant after 10 min. But in Ozone/GAC hybrid process, the molecules size over 30 kDa of HA was significantly decreased from 36.3% to 3.9%. And also the fraction of smaller molecular size below 0.5 kDa was increased from 4.8%(untreated HA) to 12.3%(in Ozone alone) and 40.1%(in Ozone/GAC) respectively at the reaction time of 120 min.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.05b
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• pp.381-382
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• 2003

오존은 여러 가지 산업적 응용분야를 가지고 있으며 특히, 광범위한 환경공학적 응용분야를 가지고 있다. 오존생성을 위해 개발된 무성방전 공정이 비교적 최근부터 악취 및 VOC를 포함한 대기오염 물질의 제거를 위해 활용되어오고 있으며 이러한 공정내에서 오존의 발생은 공정내의 오염물질 제거에 중요한 역할을 하게 된다. 따라서, 본 연구에서는 무성방전 공정에서 유입기체의 조성이 오존발생에 미치는 영향에 관해 알아보고자 하였다 (중략)

• Journal of Korean Society of Environmental Engineers
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• v.28 no.2
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• pp.137-143
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• 2006

Three candidate processes(ozone alone, UV alone and ozone/UV combined processes) were evaluated for the removal of diethyl phthalate(DEP). Of the candidates, the ozone/UV process showed the highest removal efficiency of DEP. To elucidate a major oxidant for DEP oxidation in the ozone/UV process, the effects of pH and hydroxyl radical($OH^{\circ}$) scavenger were investigated. As a result, it was found that $OH^{\circ}$ plays a important role for DEP elimination. Meanwhile, the direct reaction between ozone and DEP was negligible. Observing the pseudo first-order rate of DEP removal in ozone alone and ozone/UV processes, the different pattern was obtained from two processes. The ozone/UV process was well plotted following the pseudo first-order. but in the ozone alone process the rate was divided into fast and slow phases. DEP degradation characteristics in ozone alone and ozone/UV was also investigated by observing the HPLC spectrum. We detected unknown compounds that were guessed to DEP byproducts and observed the formation and disappearance of the unknown compounds according to reaction time. Observing of high removal of TOC in ozone/UV combined process, it was found that DEP and DEP byproducts are completely oxidized by ozone/UV combined process.

• 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.27 no.6
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• pp.567-572
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• 2005

In this study, a lab-scale test was performed to apply the ozone process in drinking water treatment plant using dissolved ai, flotation(DAF). The kinetic study on the ozone decay and hydroxyl(OH) radical formation was investigated by several parameters, such as I.D(Instantaneous ozone demand), $k_c$(ozone decomposition rate), ozone-Ct and OH radical-Ct. Ozonation of several target waters, such as raw water, DAF treated water and filtrate, was conducted to select the optimum position and dosage of ozone process. The highest value of Ozone-Ct and OH radical-Ct was observed at DAF treated water at initial run time($0{\sim}30\;min$). From the results of ozonation, the intermediate ozonation was proposed as the optimum position and the effective dose of ozone was determined to be $1{\sim}2\;mg/L$.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.5
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• pp.6-11
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• 2011

We have developed dissolved ozone decompose system in the used ozonated water for the semiconductor and LCD fabrication processes, which will be base of obtaining core process technology in the high performance, low price semiconductor and LCD fabrications. Using this technology, it is possible for the semiconductor wafer and LCD planer to process more rapid and chip, and productivity will be improved.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.4
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• pp.419-424
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• 2007

According to increase of consumer's desire for clean tap water, advanced treatment processes include with membrane, ozone, and granular activated carbon(GAC) were introduced. In order to evaluate the effect of advanced treatment processes for residual chlorine decay and trihalomethane(THM) formation in water distribution system, dissolved organic matter(DOC) removal of each advanced treatment process was investigated. The residual chlorine decay and THM formation using bottle tests were also evaluated. $UV_{254}$ removal in all advanced treatment was better than DOC removal. Especially, DOC by ozone treated was removed as 4% in contrast with sand filtered water, but $UV_{254}$ was removed about 17%. This result might be due to convert from hydrophobic DOC to hydrophilic DOC by ozonation. Ozone/GAC process was most effective process for DOC removal. The residual chlorine decay constants in treated water by sand filtration, ozonation, GAC adsorption, and ozone/GAC processes were 0.0230, 0.0307, 0.0117 and 0.0098 $hr^{-1}$, respectively. The sand filtered water was produced 81.8 ${\mu}g/L$ of THM after 190 hours of reaction time, as the treated water by ozone, GAC, and Ozone/GAC was less produced 6.0, 26.2, 30.3% in contrast with sand filtered water, respectively. Consequently, the durability of residual chlorine and reduction of THM formation were improved by advanced treatment processes.