• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 총회 및 춘계학술발표회
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• pp.322-325
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• 2003

The feasibility of treating 2-chlorophenol (2CP) contaminated soils with ozone venting was investigated in this research. Adding ozone to the existing air-venting process provides an alternative to achieve a complete in-situ treatment by oxidizing the contaminant in the process. A column study with artificial soil was used to simulate the venting process. Ozone concentrations at 2.4, 7.6 and 19.4 mg/L, and flow rates at 100 and 150 mL/min were used. The reaction times were 10, 20, 50, and 60 minutes. Blank samples using air venting were also run for comparison. It is obvious that ozone-venting had a much faster removal rate than air-venting. As higher concentration of ozone is applied, the reaction rate increased significantly. As higher concentration was applied, the flux of ozone to the liquid film increased. This also increased the removal rate of 2CP and therefore the breakthrough curve came out earlier.

• 한국환경농학회지
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• 제31권2호
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• pp.170-174
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• 2012

일반적으로 실제 하천의 EC 값은 일정하게 유지가 된다. 연속식, 반연속식 운전으로 실험한 결과 정상상태(steady state)를 보였다. 연속운전의 경우 유출수의 EC 값은 1.7 dS/m로 일정하게 유지되었으며(유입 EC = 0.1 dS/m) 반연속식운전의 경우 새로운 유입수가 유입됨으로 인해 초기 EC는 약 0.1 dS/m이고 미생물이 황을 산화함에 따라 황산염 이온이 생성되고 EC가 증가하여 30분 후 EC는 약 0.6 dS/m로 측정되었고 장시간 운전하여도 일정한 트랜드의 안정적인 값이 측정되었다. ${NO_2}^{-}-N$가 주입되면서 미생물이 저해를 받아 EC가 감소하는 경향을 보였으며 이를 통해 독성물질 주입여부를 판별할 수 있었다. 독성이 없는 유입수를 다시 유입시켰을 경우 약 4~5시간 후 반응조 내의 미생물이 원상태를 회복하여 유입 전 EC의 값이 다시 측정되었다. 황을 이용한 독성모니터링방법은 다른 여러 조건의 실험을 통해 문제점 파악 및 보완이 필요하지만 연속식 운전, 반연속식 운전 2가지 방법을 통해 독성물질을 신속하게 탐지할 수 있을 것으로 판단된다.

• 대한환경공학회지
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• 제31권10호
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• pp.831-838
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• 2009

본 연구에서는 염소, 오존 및 오존/과산화수소 산화공정에서의 의약물질 3종의 제거특성을 살펴본 결과 diclofenac과 naproxen은 쉽게 산화공정에서 제거가 가능한 것으로 나타난 반면 ibuprofen의 경우는 산화공정에서 제거가 어려운 것으로 나타났다. 오존 단독공정 보다는 오존/과산화수소 산화공정에서의 의약물질의 제거효율이 높았으며, $H_2O_2/O_3$ 비가 1 이상에서는 제거율의 상승이 둔화되었다. 염소, 오존 및 오존/과산화수소 투입농도별 의약물질 3종에 대한 산화분해 속도 상수와 반감기를 살펴본 결과 염소, 오존 단독 투입에 비하여 오존/과산화수소 공정에서의 산화분해 속도상수가 높게 나타났고, 반감기는 단축되었다.

• 청정기술
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• 제19권4호
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• pp.416-422
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• 2013

본 연구에서는 환경친화적인 측면을 고려하여 제철소 및 석유화학공장에서 많이 발생되는 부생가스인 일산화탄소와 산소를 이용하여 글리세롤로부터 글리세롤 카보네이트를 합성하는 공정에 대하여 연구하였다. 글리세롤의 산화성 카르보닐화 반응활성은 회분식 고압반응기에서 다양한 금속촉매(Cu, Pd, Fe, Sn, Zn, Cr계)에 대한 영향과 산화제, 일산화탄소와 산소의 몰 비율, 촉매량, 용매의 종류, 반응 온도 및 시간, 탈수제 첨가에 대한 반응조건들을 확인하였다. 특히, 염화구리 촉매가 우수한 반응 활성을 나타내었고, 니트로벤젠 용매상에서 글리세롤:일산화탄소:촉매의 몰 비율이 1:3:0.15, 일산화탄소:산소의 몰 비율이 2:1, 전체 반응압력이 30 bar, 반응온도 413 K, 반응시간 4시간 동안 염화구리(I)와 염화구리(II) 촉매에 대한 수율은 각각 최대 44%와 64%를 보였다. 이러한 결과로부터 구리촉매의 산화수에 따라 반응활성이 큰 차이가 보이는 것을 확인하였으며, 산화제로서의 산소의 역할은 글리세롤의 카르보닐화 반응 후 산화반응이 수반되어 부생성물인 물을 생성하는데 중요한 역할을 하고 있는 것을 확인할 수 있었다.

• Bulletin of the Korean Chemical Society
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• 제33권9호
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• pp.3009-3016
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• 2012

This study evaluated the use of iron-impregnated SBA-15 (Fe/SBA-15) as a catalyst for the oxidative degradation of persistent phenol analogues, such as 2-chlorophenol (2-CP), 4-chlorophenol (4-CP), 2-nitrophenol (2-NP), 4-nitrophenol (4-NP) and 2,4,6-trichlorophenol (2,4,6-TCP) in water. The oxidation reactions were carried out with reaction time, concentration of the phenols, amount of the catalysts, reaction temperature, pH of the reaction mixture as the process variables with or without using hydrogen peroxide as the oxidizing agent. The conversion achieved with Fe/SBA-15 at 353 K for 2-CP, 4-CP, 2-NP, 4-NP, 2,4,6-TCP was 80.2, 71.2, 53.1, 62.8, 77.3% in 5h with a reactant to $H_2O_2$ mole ratio of 1:1, and 85.7, 65.8, 61.9, 63.7, 78.1% in the absence of $H_2O_2$, respectively. The reactions followed pseudo first order kinetics. The leachability study indicated that the catalyst released very little iron into water and therefore, the possibility of secondary pollution is negligible.

• 한국환경보건학회지
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• 제32권5호
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• pp.446-450
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• 2006

In order to treat the wastewater containing organic compound, pre-treatment system connected with MSP(molecular separation process) was investigated. With the aim of selecting an optimum process of Fenton's oxidation, removal efficiency of each process in the optimum reaction condition was recommended. The $Fe/H_{2}O_{2}$(ferric sulfate to hydrogen peroxide)reagent is referred to as the Fenton's regent, which produces hydroxyl radicals by the interaction of Fe with $H_{2}O_{2}$. The powerful oxidizing ability and extreme kinetic reactively of the hydroxyl radical was well established. Increasing dosage of $Fe/H_{2}O_{2}$ increased removal efficiency as molar ratio of $Fe/H_{2}O_{2}$ between 0.2 and 2.5. Optimum dosage of molar ratio was 1. The removal efficiency for reaction condition was increased as pH decreased when the molar ratio of $Fe/H_{2}O_{2}$ was 1.7. Fenton's oxidation was most efficient in the reaction time 35 min for complex wastewater. Also, coagulation aid experiments using kaolin resulted in 3% of kaolin dosage.

• 한국환경과학회지
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• 제7권2호
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• pp.203-208
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• 1998

A simple on-line measurement system consisting of a conventional peristaltic pump, a HPLC-type heater, and a flow-through spectrophotometer is introduced for the determination of chemical oxygen demand(CODI. The system was configured such that the reaction mixture in the highly concentrated surffuric acrid medium flowing through the PTFE reaction tubing was heated at 150℃ and the absorbance of dichromate was continuously moutored at 445 m. The same addation principle as in the standard procedure was employed akcept the use of CoSO4 as a new effective catalyst. To test the system, potassium hydrogen phthalate was selected as a COD standard material. With suitably optimized reaction condition, the applicable concentration range depends on the concentration of potassium dichromate in the oxidizing reagent. With 2.0×10-3 M and 5.0×10-4M dichromate, the linear dynamic range was observed up to 400 ppm and 100 ppm, respectively. The standards in the Unear ranges were shown to be completely oxidized, which was confirmed with sodium oxalate or Mohr's salt. In all cases, the typical reproduclbility for betweenruns was 2% or less. The proposed measurement system provides the valuable in- formation for the further development of automated analysis system based on the present standard procedure.

• 웰빙융합연구
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• 제5권2호
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• pp.21-27
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• 2022

Purpose: This study is about photocatalytic technology and plasma oxidation-reduction technology. To the main cause of exposure to odor pollution, two deodorization techniques were applied to develop a module with higher removal efficiency and ozone reduction effect. Research design, data and methodology: A composite module was constructed by arranging two types of dry deodorization equipment (catalyst, adsorbent) in one module. This method was designed to increase the responsiveness to the components of complex odors and the environment. standard, unity, two types of oxidizing photo-catalyst technology and plasma dry deodorization device installed in one module to increase the potential by reduction to 76% of ozone, 100%, and 82%. Results: The complex odor disposal efficiency was 92%. Ammonia was processed with 50% hydrogen sulfide and 100% hydrogen sulfide, and ozone was 0.01ppm, achieving a target value of 0.07ppm or less. The combined odor showed a disposal efficiency of 93%, ammonia was 82% and hydrogen sulfide was 100% processed, and ozone achieved a target value of 0.07 ppm or less. Conclusions: Ozone removal efficiency was 76% by increasing Oxidation-Reduction Reaction(ORR). The H2S removal efficiency of the deodorizer was higher than that of the biofilter system currently used in sewage disposal plants.

• Bulletin of the Korean Chemical Society
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• 제25권4호
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• pp.517-524
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• 2004

Two simple and sensitive spectrophotometric methods were developed for the determination of carbocisteine, penicillamine, ethionamide and thioctic acid in bulk and in their pharmaceutical preparations using alkaline potassium permanganate as an oxidizing agent. The first one involves determination of ethionamide and thioctic acid by spectrophotometric investigation of the oxidation reaction of the two drugs. The second method involves determination of carbocisteine and penicillamine by kinetic studies of the oxidation reaction of these two drugs at room temperature for a fixed time of 20 minutes. The absorbance of the colored manganate ions was measured at 610 nm in both methods. 1-10 ${\mu}$g/mL of ethionamide and thioctic acid could be etermined by the spectrophotometric method with detection limits of 0.11 and 0.089 ${\mu}$g/mL for the two drugs respectively. 2-10 ${\mu}$g/mL of carbocisteine and penicillamine could be determined by the kinetic method with detection limits of 0.14 and 0.21 ${\mu}$g/mL respectively. The two methods were successfully applied for the determination of these drugs in their dosage forms.

• 한국연소학회지
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• 제4권1호
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• pp.27-38
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• 1999

We constructed a wire-cylinder type pulsed corona discharge system for $NO_x$ removal, which was operated in room temperature. A emission spectrometer was built with a boxcar averager and monochrometer equipped with photo-multiplier tube detector. The sensitivity of the emission spectrometer was greatly improved by synchronizing the emission spectrometer with pulsed corona discharge system using a triggered spark-gap switch. $N_2$ spectrum($c^3{\Pi}_u{\rightarrow}X^1{\Sigma}_g{^+}$) was measured in the range of 300 - 450 nm and oxidizing OH radical emission($A^2{\Sigma}^+{\rightarrow}X^2{\Pi}$) was measured in case $N_2$ was supplied with water bubbling. As wet gas composition of inlet $N_2$ supplied in the discharge system increased, the intensity of OH emission was increased and saturated at wet gas composition 50%. We also investigated additive effect of $C_2H_4,\;H_2O,\;H_2O_2$ on the intensity of OR emission and $NO/NO_2/NO_x$ reduction and analysed the related reaction mechanism in corona discharge process. $H_2O_2$ additive increased the intensity of OH emission and $NO/NO_x$ reduction.