• Title/Summary/Keyword: Pre-ozone

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Development of High Performance Ozone Generating Controller (다중 펄스 방식에 의한 고성능 오존발생 제어장치 개발)

  • 이홍희;김형준
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.52 no.5
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    • pp.226-226
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    • 2003
  • When an excessive voltage is applied to the discharge gap in ozone generator, the discharge room temperature becomes higher. As is well own, the efficiency of the ozone generation is deteriorated by the excessively hot temperature because of the decomposition reaction. In this paper, the simple small capacity ozone generating controller has been introduced, which provides effective and stable silent discharge characteristics over wide range input power. The proposed power controller has two important advantages, which imply that the production rate of ozone can be controlled linearly according to the delivered power and the surplus energy is recovered to the source. The experimental results are given to verify the performance of the pre proposed controller.

Development of High Performance Ozone Generating Controller (다중 펄스 방식에 의한 고성능 오존발생 제어장치 개발)

  • 이홍희;김형준
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.52 no.5
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    • pp.226-230
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    • 2003
  • When an excessive voltage is applied to the discharge gap in ozone generator, the discharge room temperature becomes higher. As is well own, the efficiency of the ozone generation is deteriorated by the excessively hot temperature because of the decomposition reaction. In this paper, the simple small capacity ozone generating controller has been introduced, which provides effective and stable silent discharge characteristics over wide range input power. The proposed power controller has two important advantages, which imply that the production rate of ozone can be controlled linearly according to the delivered power and the surplus energy is recovered to the source. The experimental results are given to verify the performance of the pre proposed controller.

Effect of Ozone Injection on Dewaterability and Thickening of Sewage Sludge (하수 슬러지 농축 및 탈수성에 미치는 오존의 영향)

  • Hwang, Kyeoung-Sa;Kim, Moon-Ho;Bae, Yoon-Sun;Park, Chul-Hwi
    • Journal of Korean Society of Water and Wastewater
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    • v.19 no.6
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    • pp.800-808
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    • 2005
  • It is required to propose an alternatives for appropriate sludge treatment owing to persistent construction of sewage treatment plant and increase of sewage sludge quantity. In order to treat sludge more efficiently, the methods which reduce the cost of sludge treatment have been studied such as sludge reduction and conditioning. Especially ozone treatment reduces solid quantity and improves separation of solid-liquid at the same time. Therefore ozone treatment have a positive effect on reduction and stabilization of sludge. So, this study applied ozone to sewage sludge and induced cell destruction of sludge. By comparing with the correlation between thickening and dewatering, and evaluating moisture content and solubilization of cake, this study verificates the effect of process improvement for ozone pre-treatment. In J-STP case, according to ozone dose solid flux increased about 12 times from $1kg/m^2{\cdot}h$ to $12kg/m^2{\cdot}h$. Also this plant were capable to shorten thickening time from 40 minutes to 6~7 minutes. Thus it is expected to reduce volume and retention time of thickener. On pH effect factor, dewatering at pH4 was more than at pH11, $3.05{\times}10^{11}$ and $3.82{\times}10^{11}(m/kg)$. But effect of pH was analogous to ozone, $2.81{\times}10^{11}(m/kg)$. The effect of pH on thickening was similar to law sludge, $0.68(kg/m^2{\cdot}h)$, and the effect of ozone injection on thickening was the biggest, $3.45(kg/m^2{\cdot}h)$. The COD solubilization rate improved from about 5 to 30%. So it is judged that we are able to utilize most solubilized sludge to another sewage treatment plants.

Changes in Quality of 'Mipung' Chestnut during Storage by Pre-treatment Methods after Harvest (수확 후 전처리 방법에 따른 '미풍' 밤의 저장 중 품질 변화)

  • Oh, Sung-Il;Park, Yunmi;Kim, Mahn-Jo
    • Journal of Korean Society of Forest Science
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    • v.104 no.4
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    • pp.558-563
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    • 2015
  • The effects of pre-treatment methods (water cooling, water cooling+ozone, precooling+microbubble, water cooling+ozone+microbubble) after harvest on the quality of 'Mipung' chestnut were studied. Changes in quality of chestnut were greater precooling treatments effect than washing treatments. But, decaying rate and total microorganism were significantly differences among treatments. The decaying rate after 12 weeks storage was highest at 20.0% in non-treatments and lowest at 3.3% in water cooling+ozone and water cooling+ozone+microbubble treatments. The total microorganism immediately after washing treatments was in the order non-treatments (4.4 log CFU/g) > water cooling treatments (4.0 log CFU/g) > water cooling+ozone+microbubble treatments (3.5 log CFU/g) > water cooling+ozone treatments (3.4 log CFU/g) > water cooling+microbubble treatments (3.3 log CFU/g), and after 12 weeks storage was increased within 4.7 to 5.9 log CFU/g. Thus, the washing treatments, especially ozone treatments, extended the shelf-life of the 'Mipung' chestnut by inhibiting the decaying.

Application of Ozone Oxidation to Reduce the Biological Treatment Time of Petrochemical Wastewater (석유화학 폐수의 생물학적 처리시간 단축을 위한 오존 산화의 적용)

  • Hong, Eun-Sik;Kim, Hyun-Suk;Lee, Sang-Hee;Chung, Jin-Suk;Shin, Eun-Woo;Ryu, Keun-Garp;Yoo, Ik-Keun
    • Journal of Korean Society of Environmental Engineers
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    • v.28 no.5
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    • pp.573-576
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    • 2006
  • The efficacy of integrated ozone oxidation-biodegradation treatment was examined in the treatment of petrochemical wastewater with a special focus on the overall treatment time. When raw wastewater with chemical oxygen demand(COD) of 70-80 mg/L was oxidized by ozone, approximately 20% of initial COD was removed in less than 1.5 min at a dosing rate of 400 mg $O_3/L{\cdot}h $. No further decrease in COD was observed for the extended ozone treatment up to 30 min. Biological treatment alone showed a rapid reduction of COD to 40-50 mg/L, subsequently resulting in the decreased rate of COD removal. Pre-treatment by ozone before biological treatment did not significantly affect the specific rate of COD removal in a biological treatment. When ozone oxidation followed biological treatment, the extent of COD removal by ozone oxidation was greater compared to that of biologically-treated wastewater for a shorter time. Taken together, it was decided that the biological treatment time could be reduced if the treatment processes of concern will be properly arranged.

A Study on Substrate Pre-treatment for Mathane Production Performance (메탄생성 효율증진을 위한 소화원료 전처리 연구)

  • Jeong, K.H.;Ryu, S.H.;NamGung, K.C.;Kim, J.H.;Kwag, J.H.;Ann, H.K.;Yoo, Y.H.
    • Journal of Animal Environmental Science
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    • v.17 no.3
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    • pp.197-204
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    • 2011
  • During the process of anaerobic digestion, hydrolysis of substrate is the key factor determining methane production efficiency. The hydrolysis efficiency are directly affected by biodegradability of substrate. In this study, three types of pre-treatment methods were tested to enhance biodegradability effectiveness. By the application of blender and the Cavitation treatment, the SCODcr increased from 24,723 mg/l to 24.726~29,175 mg/l and to 25,589~26,456 mg/l, respectively. In case of ozone treatment, the SCODcr decreased from 24,723 mg/l to 22.540~23,988 mg/l. In batch experiment, there was a little improvement of the biochemical methane potential (BMP) by the blender and the cavitation treatment. In contrast, the BMP somewhat decreased by ozone treatment. This result shows that higher anaerobic digestion efficiency of livestock manure could be obtained through pre-treatment of substrate.

A Study on the Solubilisation of Excess Sludge using Microbubble Ozone (잉여슬러지 가용화를 위한 마이크로버블 오존 이용에 관한 연구)

  • Lee, Shun-Hwa;Jung, Kye-Ju;Kwon, Jin-Ha;Lee, Se-Han
    • Journal of Korean Society of Environmental Engineers
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    • v.32 no.4
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    • pp.325-332
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    • 2010
  • This study was conducted with the experiment of solubilisation of excess sludge by microbubble ozone process. To improve ozone contact efficiency, microbubble ozones which its diameter were the avearge 30 ${\mu}m$, microbubble size less than 40 ${\mu}m$ occupied about over 90% of all. In treating sludge using microbubble ozones, in case microbubble ozones are injected at microbubble ozone dosage of 0.34 g $O_3/g$ SS or less regardless of sludge concentration, microbubble ozone consumption rate was found to be 100% with no emission of waste ozones. In treating sludges by each concentration, in case the initial SS concentration of sludge is set to 6,447 mg/L, 5,557 mg/L, 3,180 mg/L, 1,092 mg/L and 515 mg/L, the amount of removed SS tended to increase with increase in initial SS concentration for the same microbubble ozone dosage, and treatment of sludge with high initial SS concentration was effective in raising the oxidation efficiency of microbubble ozones. On the other hand, as a result of reviewing acid, alkali and microbubble ozone treatment as composite treatment of sludge, use of acid treatment for the pre-treatment of microbubble ozone was more effective than alkali treatment, and in case of treatment at microbubble ozone dosage 0.05g $O_3/g$ SS with the concentration of sulfuric acid infused in the sludge, the amount of removed SS, 153.9 g, was 1.9 times more than 81.2 g the amount of single treatment of microbubble ozone.

The Variations of Stratospheric Ozone over the Korean Peninsula 1985~2009 (한반도 상공의 오존층 변화 1985~2009)

  • Park, Sang Seo;Kim, Jhoon;Cho, Nayeong;Lee, Yun Gon;Cho, Hi Ku
    • Atmosphere
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    • v.21 no.4
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    • pp.349-359
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    • 2011
  • The climatology in stratospheric ozone over the Korean Peninsula, presented in previous studies (e.g., Cho et al., 2003; Kim et al., 2005), is updated by using daily and monthly data from satellite and ground-based data through December 2009. In addition, long-term satellite data [Total Ozone Mapping Spectrometer (TOMS), Ozone Monitoring Instrument (OMI), 1979~2009] have been also analyzed in order to deduce the spatial distributions and temporal variations of the global total ozone. The global average of total ozone (1979~2009) is 298 DU which shows a minimum of about 244 DU in equatorial latitudes and increases poleward in both hemispheres to a maximum of about 391 DU in Okhotsk region. The recent period, from 2006 to 2009, shows reduction in total ozone by 6% relative to the values for the pre-1980s (1979~1982). The long-term trends were estimated by using a multiple linear regression model (e.g., WMO, 1999; Cho et al., 2003) including explanatory variables for the seasonal variation, Quasi-Biennial Oscillation (QBO) and solar cycle over three different time intervals: a whole interval from 1979 to 2009, the former interval from 1979 to 1992, and the later interval from 1993 to 2009 with a turnaround point of deep minimum in 1993 is related to the effect of Mt. Pinatubo eruption. The global trend shows -0.93% $decade^{-1}$ for the whole interval, whereas the former and the later interval trends amount to -2.59% $decade^{-1}$ and +0.95% $decade^{-1}$, respectively. Therefore, the long-term total ozone variations indicate that there are positive trends showing a recovery sign of the ozone layer in both North/South hemispheres since around 1993. Annual mean total ozone (1985~2009) is distributed from 298 DU for Jeju ($33.52^{\circ}N$) to 352 DU for Unggi ($42.32^{\circ}N$) in almost zonally symmetric pattern over the Korean Peninsula, with the latitudinal gradient of 6 DU $degree^{-1}$. It is apparent that seasonal variability of total ozone increases from Jeju toward Unggi. The annual mean total ozone for Seoul shows 323 DU, with the maximum of 359 DU in March and the minimum of 291 DU in October. It is found that the day to day variability in total ozone exhibits annual mean of 5.7% in increase and -5.2% in decrease. The variability as large as 38.4% in increase and 30.3% in decrease has been observed, respectively. The long-term trend analysis (e.g., WMO, 1999) of monthly total ozone data (1985~2009) merged by satellite and ground-based measurements over the Korean Peninsula shows increase of 1.27% $decade^{-1}$ to 0.80% $decade^{-1}$ from Jeju to Unggi, respectively, showing systematic decrease of the trend magnitude with latitude. This study also presents a new analysis of ozone density and trends in the vertical distribution of ozone for Seoul with data up to the end of 2009. The mean vertical distributions of ozone show that the maximum value of the ozone density is 16.5 DU $km^{-1}$ in the middle stratospheric layer between 24 km and 28 km. About 90.0% and 71.5% of total ozone are found in the troposphere and in the stratosphere between 15 and 33 km, respectively. The trend analysis reconfirms the previous results of significant positive ozone trend, of up to 5% $decade^{-1}$, in the troposphere and the lower stratosphere (0~24 km), with negative trend, of up to -5% $decade^{-1}$, in the stratosphere (24~38 km). In addition, the Umkehr data show a positive trend of about 3% $decade^{-1}$ in the upper stratosphere (38~48 km).

Study on the Removal of Fluorescent Whitening Agent by Pretreatment Ozone Oxidation for MBR Process Application (MBR 공정 적용을 위한 전처리 오존산화에 의한 형광증백제 제거 연구)

  • Choi, Jang-Seung;Ryu, Seung-Han;Shin, Dong-Hun;Lee, Jae-Hun;Lee, Soo-Chol;Kim, Sung-Gi;Ryu, Jae-Young;Shin, Won-Sik;Lee, Seul-Ki;Park, Min-Soo
    • Textile Coloration and Finishing
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    • v.29 no.1
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    • pp.11-17
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    • 2017
  • In this study, ozone oxidation experiment was carried out for the removal of fluorescent whitening agent which is widely used in textile dyeing and paper industry. The stilbene fluorescent whitening agent has been industrialized since the earliest, and the amount of current production is the highest. Due to the characteristics of the fluorescent whitening agent that can not be removed by conventional wastewater treatment methods, the fluorescent whitening agent in wastewater treatment has difficulty in using as recycled water in the process. Pre-treatment ozone oxidation experiment was conducted prior to the introduction of Membrane Bio Reactor(MBR) treatment process by converting biodegradable materials into biodegradable materials. The removal efficiencies of fluorescent whitening agents, a diaminostilbenedisulfonic acid derivative by ozone oxidation were evaluated by $UV_{254}$ Scan, $COD_{Mn}$, T-N and color using a synthetic wastewater sample ($COD_{Mn}=433.0mg/{\ell}$) and paper and paper mill wastewater ($COD_{Mn}=157.2mg/{\ell}$).

양파 저장 시 오존처리에 의한 부패방지와 저장성 향상

  • Hwang, Deok-Seok;Kim, Hong-Myeong;Gang, Seon-Cheol
    • 한국생물공학회:학술대회논문집
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    • 2000.11a
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    • pp.441-442
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    • 2000
  • This study was conducted to extend the storage period of onion. After pre-drying process of onion, its storage was investigated at room temperature during a month. When ozone was treated with the concentration of 3 ppm in warehouse, the weight loss and the rotten rate of onion were remarkably decreased compared with control. Typical odor of onion was completely removed by the ozone treation during the storage.

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