• Journal of Korean Society of Environmental Engineers
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• v.22 no.5
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• pp.869-877
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• 2000

A mechanism of ozonation of simulated soil slurry contaminated by phenanthrene and benzo[a]pyrene has been studied under various conditions. The effects of soil media(BS, S, GB), radical scavenger, ozone input ratio(0.17~0.73mg/min), bicarbonate ion, and humic acid were investigated, BS showed the highest removal efficiency in media tested. The generation of OH-radical via the catalytic decomposition of ozone on active sites of the natural sand was confirmed by OH-radical scavenger experiments. The enhanced removal efficiency by OH-radical was indirectly quantified to be about 22%. As initial concentration of humic acid(as sodium salt) was increased, pseudo first-order rate constant ($k_o$) of phenanthrene was decreased from $1.37{\times}10^{-2}s^{-1}$ to $0.53{\times}10^{-2}s^{-1}$. The amount of ozone required to oxidize 80% of the initial mass of phenanthrene(10mg/kg) and benzo[a]pyrene(10mg/kg) was 67.2mg/kg-soil and 48.0mg/kg-soil, respectively.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.8
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• pp.627-634
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• 2009

This study was done to find out the formation mechanism of chlorate by electrochemical process using chloride ion ($Cl^-$) as an electrolyte. Firstly, the effective factors such as pH and initial chloride concentration were figured out to see the formation property of chlorate during electrolysis. And the relation of free chlorine, and mixed oxidants such as OH radical and ozone with chlorate were estimated to concretize the formation mechanism. As a result, it was found that the major reaction of chlorate formation would be electrochemical reaction with free chlorine, and also the direct oxidation of chloride ion and the reaction by OH radical were participated in the formation of chlorate. Moreover, it was observed that formed chlorate was oxidized to perchlorate. Lastly, the optimum condition was recommended by comparing free chlorine with chlorate concentration during the electrochemical process with the different electrode separation.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.2
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• pp.113-119
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• 2011

The study purpose was to examine an effect of zero emission of excess sludge on biological reactor and treated water quality within the biological reactor in the process of biological treatment combined with excess sludge reduction system with ozone. Under an ozone injection rate 0.03 g $O_3/g$ SS, Sludge Disintegration Number (SDN) 3 and less than pH 4 as pre-treatment process, it was possible to maintain a stable biological treatment process without sludge disintegration. In the test of $OUR_{max}$, of sludge, its value was hardly under the condition of ozone injection rate 0.03 g $O_3/g$ SS. There were almost no changes of MLVSS/MLSS within biological reactor followed by a solubilization of excess sludge. Accumulation of microorganism within biological reactor was also not observed. After solubilization of excess sludge, an increase for organic matter and SS concentrations of an effluent was not observed and T-N concentration was reduced by increasing nitrification and denitrification rate within biological reactor. Most of T-P was not removed by zero emission of excess sludge and was leaked by being included in effluents.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.12
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• pp.1292-1297
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• 2005

The use of ozone in water and wastewater treatment systems has been known to be a process that is limited by mass transfer. The most effective way to overcome this limitation is to increase the interfacial area available for mass transfer by decreasing the size of the ozone gas bubbles that are dispersed in solution. Electrostatic spraying(ES) of ozone into water was investigated in this work as a method of increasing the rate of mass transfer of ozone into a solution and thereby increasing the rate of phenol oxidation. Results were obtained for ES at input power levels ranging from 0 to 4 kV and compared with two different pore-size bubble diffusers($10{\sim}15{\mu}m$ and $40{\sim}60{\mu}m$). It was determined that the rate of mass transfer could be increased by as much as 40% when the applied voltage was increased from 0 to 4 kV as a result of the smaller bubbles generated by ES. In addition, ES was shown to be more effective than the medium-pore-size($10{\sim}15{\mu}m$) bubble diffuser and the best results were achieved at low gas flow rates.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1999.07a
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• pp.118-123
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• 1999

화석연료의 연소에 의해 발생되는 질소산화물(NOx)은 가스상의 대기오염물질로서 인류의 생활환경에 유해함은 물론 식물의 생장속도에도 막대한 영향을 미치고 있으며, 질소산화물은 햇빛의 존재 하에서 탄화수소와 광화학 반응을 하여 광화학적 산화물과 오존 등을 생성하는 광화학적 스모그 생성에 관여하고, 이러한 광화학 스모그는 사람에게 만성의 호흡기 질환을 유발하거나 시정거리의 감소를 가져온다. (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2001.11a
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• pp.225-226
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• 2001

휘발성 유기화합물(VOCs)은 광화학적 오존 형성으로 인한 간접 오염뿐만 아니라 그 자체가 독성을 지니고 있어 직접적으로도 인체에 유해한 영향을 줄 수 있으며, 유류 및 유기 용제를 사용하는 작업장에서뿐만 아니라 연소 관련 오염원이 없는 실내 환경에서도 일부 VOCs는 높은 농도를 나타낼 수 있으므로 작업장 및 실내 환경에서의 VOCs 처리에 대한 중요성이 증대되고 있다. (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2002.04a
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• pp.319-320
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• 2002

포름알데하이드(HCHO)는 보건학적인 영향과 광화학 스모그 형성과정의 중요한 역할로 인해 많은 연구의 대상이 되어왔다. 포름알데하이드(HCHO)의 도심지 대기 환경에서 가장 중요한 인위적인 발생원은 산업활동 및 자동차의 배기가스이며 식물의 연소과정(biomass burning)에서도 방출되는 것으로 알려져 있다. 또한 대기환경에 존재하는 휘발성 유기화합물들과 OHㆍ과의 광 화학적 산화과정을 통하여 2차적으로 형성된다. 한편, 주요 소멸과정으로는 광분해(photolysis) 과정과 OHㆍ과의 반응이다. (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2001.11a
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• pp.177-178
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• 2001

전지구적으로 볼 때, 삼림은 대기 중으로 유입되는 자연적 VOCs의 주요 배출원이다. 특히 우리나라의 경우에는 산림이 전 국토의 65%를 차지하여 자연적 VOCs의 주요 배출원일 것으로 추정된다. 자연적 VOCs는 산화과정에서 발생된 에어로졸입자 생성에 의한 blue haze 발생이나 광화학 반응으로 인한 오존생성을 발생시켜 대기질에 악영향을 미칠 수 있다. 그러나, 산림은 인간에서 삼림욕을 즐길 수 있도록 하는 등 최근에는 인간에게 좀 더 이로운 존재임이 과학적으로 입증되고 있다. (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.05b
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• pp.100-101
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• 2003

휘발성 유기 화합물(Volatile organic compounds, VOCs)은 산업공정에서 유기 용제로 사용되며 수송, 저장 및 취급시 대기로 쉽게 방출된다. 또한 자동차 배출가스, 소각로, 쓰레기 매립장, 폐수 처리시설 및 일반 가정에서의 각종 연소 과정에서도 유출된다. VOCs 의 유출은 그 자체가 인체에 유해할 뿐 아니라, 대기 중에 배출되어 질소 산화물과 함께 광화학 반응을 일으킴으로서 오존 또는 알데히드와 같은 2차 오염물질을 생성시켜 오존층 파괴 및 지구 온난화, 산성비 등으로 지구 환경에 악영향을 초래하고 있다. (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.05b
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• pp.289-290
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• 2003

NMHC (non-methane hydrocarbons)는 $C_2$- $C_{l2}$의 탄화수소로 구성되며 NOx와 함께 오존을 생성시킨다. NMHC에 카보닐 화합물과, 카본수가 증가하여 휘발성이 떨어지더라도 광화학 반응성이 있는 탄화수소가 추가되면 우리에게 보다 익숙한 VOC (volatile organic compounds)가 된다 (Watson et al., 2001). NMHC는 자동차, 가스 및 석유 정제시설, 주유소, 세탁공업, 산업공정 등으로부터 배출된다. NMHC는 오존 등 광화학 산화제 뿐 아니라 미세입자 생성에도 직접 또는 간접적으로 관여하여 광화학 스모그를 유발시킬 수도 있다. (중략)략)