• 대한환경공학회지
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• 제22권10호
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• pp.1825-1832
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• 2000

유류화합물(디젤)로 오염된 불포화층 토양에 대한 현장오존복원공정의 기초연구로, 토양조건에 따른 오존의 이동과 분해, 디젤과의 반응경향을 조사하였다. 건조상태에서 유기물을 제거한 모래와 glass beads 충진컬럼에서 기상 오존의 분해를 조사한 결과 일차반응으로 가정시 반응 속도상수값(k)이 각각 $9.9{\times}10^{-3}s{^{-1}}$와 $4.3{\times}10^{-4}s{^{-1}}$로 나타나 모래의 경우 철 (Fe), 망간(Mn) 성분 등의 촉매작용으로 25배 가량 반감기가 짧은 것을 확인할 수 있었다. 디젤로 오염시킨 현장 토양과 모래를 컬럼에 충진하여 동일조건하에서 오존주입시 토양입자의 크기와 유 무기물의 함량 차에 의한 오존이동상에 지체효과 및 소모량의 차이를 관찰하였고, 50mL/min의 유속에서 공기만을 주입시 DRO(diesel range organic) 기준 초기 디젤총량($800{\pm}50mg/kg$)의 30%가 제거된데 비해 오존을 6mg/min으로 16시간 주입한 결과 각각 80% 이상이 제거되었다. 오존주입시간에 따라 컬럼의 유출 입부에 잔류하는 TPH(total petroleum hydrocarbon)와 DRO 중 aliphatic계열 8개 물질들의 농도를 비교/분석한 결과, 낮은 탄소수 물질들로의 전환과정을 거쳐 유체의 흐름에 따라 컬럼 밖으로 이동됨을 확인하였고, 토양내 수분함량은 오염 토양복원에 오존을 적용시 중요한 인자임을 확인하였다.

• 한국물환경학회지
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• 제28권5호
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• pp.704-716
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• 2012

본 논문은 California의 South Lake Tahoe, 서울 뚝섬정수장 그리고 성남 복정정수장에서 2010년 2월에서 2012년 2월까지 수행된 파일럿 실험에 대한 분석결과를 기초로 작성되었다. 본 실험의 목적은 첫째, 한강을 원수로 하는 모래여과 처리수에 대한 오존 및 과산화수소(Peroxone)의 반응특성을 파악하고, 둘째는 AOP(고도산화공정)을 통해 맛 냄새 유발물질인 2-methylisoborneol(MIB)를 제거하기위한 경험적인 오존 및 과산화수소의 투입량을 결정하고자 하였다. 또한 셋째로, 처리공정이후 인체에 안전한 잔류오존농도로 감소시키기 위한 최적 투입량을 결정하고자 하였다. 본 실험은 계절의 기온변화에 따라 저수온 및 고수온의 조건하에서 실시간으로 수행되었다. 본 실험을 통해 오존의 분해속도는 온도와 pH에 영향을 받는 것으로 나타났으며, 이는 다른 연구결과와 일치한다. 원수로 모래여과수에 MIB를 40~50ng/L의 농도로 투입하였으며, 모든 경우에서 7ng/L 이하로 처리되었으며 대부분의 경우에서 검출(ND)되지 않았다. Peroxone은 MIB을 제거할 뿐아니라 오존을 단독으로 사용한 경우보다 오존+과산화수소 동시에 투입한 경우에 잔류오존농도가 더 낮았다. 저수온에서 상당량의 오존이 반응 및 분해를 통해 감소된다. 본 실험을 통해 "Pre-Conditioned" 과산화수소를 적용함으로써 초기 반응율을 향상시키고 잔류오존농도를 낮출 수 있었으며, 약품의 과투입 및 효율저하를 방지하는 과산화수소의 투입 위치 및 구성 그리고 투입방법을 제시하였다.

• 공업화학
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• 제23권6호
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• pp.608-613
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• 2012

유전체 배리어 방전 플라즈마를 모사 농산물 저장시설($1.0m^3$)의 에틸렌 제거에 적용하였다. 에틸렌이 포함된 공기를 플라즈마 반응기에 유입시켜 처리한 후 다시 농산물 저장시설로 재순환하는 방식으로 시험을 수행하였다. 주요 운전변수는 방전전력, 순환기체 유량, 초기 에틸렌 농도 및 처리시간이었다. 에틸렌의 분해속도는 주로 방전전력과 처리시간에 의해 결정되었다. 다른 조건을 일정하게 유지한 상태에서 플라즈마 반응기 후단에 이산화망간 오존분해 촉매를 설치했을 경우 오존분해 촉매가 없을 때 보다 에틸렌 제거속도가 더 빨랐는데, 이 결과는 플라즈마 반응기에서 배출되는 오존이 농산물 저장시설에 유입 축적되어 에틸렌을 추가적으로 분해했기 때문이다. 에틸렌 초기 농도 50 ppm을 기준으로 하면 이를 완전히 분해하기 위한 에너지 요구량은 약 60 kJ이었다.

• 상하수도학회지
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• 제12권3호
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• pp.21-29
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• 1998

The ozone/GAC process, sometimes termed BAC(Biological Activated Carbon) appeared to be effective for the removal of soluble organic matters in the drinking water Chabrol is a simple model for the simulation like as the variation of HPC and BDOC in the BAC tower. This study were carried out to calibrate of HPC and BDOC and to evaluate $H_1$ and $H_2$ of ozone-treated water with Chabrol model. BDOC values of the ozone-treated water and BAC effluent are analyzed using method of Levi and Joret. As the ozone-treated water and BAC Effluent are incubated, the HPC are increased up to 0.24 mgC/l and 0.09 mgC/l respectively. $H_1$ and $H_2$ of the ozone-treated water is 0.3 mgC/l and 0.349 mgC/l respectively and Chabrol model for BAC tower can be calibrated.

• 대한전기학회논문지:시스템및제어부문D
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• 제52권5호
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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.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제52권5호
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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.

• 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.

• 조명전기설비학회논문지
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• 제25권10호
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• pp.116-124
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• 2011

In this work, the effect of the initial concentration of methanol and ethanol, and the addition of oxygen molecules were discussed to improve the hydrogen generation using non-thermal plasma reactor effectively. In addition, the effect of ozone decomposition catalyst of manganese dioxide and its quantity was investigated. First, hydrogen concentration increased until an initial concentration of about 40,000[ppm] of methanol and thereafter it was saturated. Henceforth, hydrogen concentration decreased with increasing the oxygen percent on the carrier gas of nitrogen about both substances. Related with the effect of catalyst, it increased upto 60[g], but it was not changed largely after that. Consequently, it is confirmed that the hybrid process using plasma process and catalytic surface chemical reaction is a very promising way to increase the efficiency of hydrogen generation as investigated in this work.

• 공업화학
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• 제32권4호
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• pp.483-486
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• 2021

Catalytic ozonation of methyl ethyl ketone (MEK) has been examined over mesoporous MnO_x/Al₂O₃ (MA) catalysts developed by a solvent deficient method using two different manganese precursors including manganese chloride (C) and manganese sulfate (S) at room temperature. The maximum catalytic activities of MA with C (MEK removal efficiency and ozone decomposition of 98.4 and 93.7%, respectively) were higher than those of MA with S (MEK removal efficiency and ozone decomposition of 96 and 68%, respectively). Also the catalytic stability of MA with C was much higher than that of MA with S. The physico-chemical properties of catalysts are well correlated with the activity results, which confirmed that fine dispersion of MnO_x species with high ratios of Mn³⁺/Mn⁴⁺ and more acid sites are attributed to the higher catalyst stability for the MA-C catalyst.

• Journal of Electrical Engineering and Technology
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• 제13권6호
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• pp.2392-2401
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• 2018

Creepage discharge faults in air on solid insulating material play a vital role in degradation and ageing of material which ultimately leads to breakdown of power equipment. And electric discharge decompose air in to its by-products such as Ozone and $NO_x$ gases. By analyzing air decomposition gases is a potential method for fault diagnostic in air. In this paper, experimental research has been conducted to study the effect of creepage discharge on rate of generation of air decomposition by-products using different insulating materials such as RTV, epoxy and fiberglass laminated sheet. Moreover XRF analysis has been done to analyze creepage discharge effect on these insulating materials. All experiments have been done in an open air test cell under constant temperature and pressure conditions. While analysis has been made for low and high humidity conditions. The results show that the overall concentration of air decomposition by-products under creepage discharge in low humidity is 4% higher than concentration measured in high humidity. Based on this study a mathematical relationship is also proposed for the rate of generation of air decomposition by-products under creepage discharge fault. This study leads to indirect way for diagnostic of creepage discharge propagation in air.