• Journal of Korean Society for Atmospheric Environment
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• v.17 no.1
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• pp.97-104
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• 2001

Decomposition of trichloroethlyene(TCE) in electron beam irradiation was examined on order to obtain information on the treatment of VOC in air. Air containing vaporized TCE has been studied in a flow reactor with different reaction environments, at various initial TCE concentration and in the presence and absence of water vapor. Maximum decomposition was observed in oxygen reaction environment and the degree of decomposition was about 99% at 20kGy for 2,000ppm initial TCE. The concentration of TCE exponentially decreased with dose in air and pure oxygen. The effect of water vapor on TCE decomposition efficiency was examined. The decomposition rate of TCE in the presence of water vapor (5,600 ppm) was approximately 10% higher than that in the absence of water vapor. Dichloroacetic acid, dichloroacethyl chloride and dichloroethyl ester acid were identified as primary products of this reaction adn were decomposed and oxidized to yield CO and $CO_2$. Perchloroethylene, hexachloroethane, chloroform and carbon tetrachloride were also observed as highly chlorinat-ed by products.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.93-94
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• 2001

Biofilter operating parameters such as incoming VOCs concentrations, temperature, and packing materials were studied. The performance of a lab-scale biofilter in the treatment of air contaminated with mixtures vac has been evaluated in this study. The biofilter was operated for 80 days packed with compost. Empty bed residence time (EBRT) was 3 to 1.5 min. After 80 days of operation, the removal efficiency was 94% and 73% at $25^{\circ}C$ and $45^{\circ}C$, respectively. Removal efficiencies of m-xylene (93%), o-xylene (92%) and toluene (92%) were better than that of benzene (84.7%).

• KSBB Journal
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• v.15 no.5
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• pp.501-506
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• 2000

A bench-scale air biofilter was evaluated for the removal of volatile organic compounds (VOCs) from a gas stream. Compost and peat were used as the biological attachment media. Biofilter operating parameters such as incoming VOCs concentrations, temperature, and packing materials were examined. After 26 days of acclimation periods, at 25$^{\circ}C$ and 45$^{\circ}C$, the biofilter removed more than 90% of 30 to 72 mg/㎥ of total VOC. After 40 days of operation, the concentrations of isoprene, toluene, and m-xylene were reduced to 96∼99, 91∼93, and 91∼93% of the original concentrations. VOC removal efficiency was not affected by the temperature. The medium pH was maintained near neutral (pH 6.5∼7.1). After 37 days of operation, the total bacteria count in the biofilter media increased to 1.12${\times}$10(sup)8 cells/g of medium.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2001.05a
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• pp.59-61
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• 2001

휘발성 유기화합물로 오염된 가스 제거를 위한 최적 조건을 찾고자 VOC를 생물학적 처리방법 중 하나인 생물여과기를 이용하여 조사하였다. 100여일 운영 후, 25와 $45^{\circ}C$조건 보다 $32^{\circ}C$조건에서 휘발성 유기화합물의 분해력이 높게 나타났다. 생물여과기는 다양한 휘발성 유기화합물 농도와 EBRT 조건에서 약 100일간 운전되었으며, 최대 제거량 128 $g/m^{3}h$에서 113 $g/m^{3}h$ 임을 알 수 있었다. 휘발성 유기화합물은 체류시간 1～3 min에서 제거율이 30～96%까지 변화하는 것을 보여 주었다. 이상의 휘발성 유기화합물 중 일부는 심각한 환경문제를 야기시키므로 이들 휘발성 유기화합물을 완전 제거하거나 최소화시킬 수 있다면 생물여과 시스템은 안정성과 경제적 측면에서 매우 바람직하겠다. 본 연구 결과는 미생물을 이용한 생물여과법이 효과적인 처리 공정임을 보여주었고 혼합된 휘발성 유기화합물이 존재하더라도 그 성분을 동시에 분해할 수 있다는 결과를 보여 주었다.

• Environmental engineer
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• v.24 s.254
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• pp.54-59
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• 2007

본 기술은 각종 산업시설과 환경 기초 시설로부터 대기중으로 배출되는 악취 및 휘발성 유기화합물(Volatile Organic Chemicals; VOC)을 미생물의 분해 작용을 활용하여 제거하는 장치로 오염 물질의 분해과정에서 미생물의 과다생장에 의한 악취 및 휘발성 유기화합물 제거장치의 막힘현상을 미생물 고정화 담체의 교반과 살수과정을 통해 담체표면의 생물막을 효과적으로 제거하는 방법을 이용하여 오염 가스속에 함유되어 있는 악취 및 휘발성 유기화합물을 효율적으로 제거할 수 있는 기술이다. 특히, 미생물 담체의 교반 장치는 미생물 고정화 담체를 교반시켜 생물막을 탈리 시킴으로써 미생물의 생장에 의한 막힘 현상과 이로 인한 압력 손실 증가와 악취 및 휘발성 유기화합물의 제거성능의 저하를 근본적으로 해결할 수 있다.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2001.11a
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• pp.415-416
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• 2001

최근 환경오염에 대한 관심이 고조되면서 VOCs를 비롯한 각종 악취물질 제거에 광촉매가 각광받고 있다. 광촉매는 기존 오염물질 제거기술과는 달리 광촉매 하나로서 복합적인 오염물질을 한꺼번에 분해할 수 있는 장점이 있다. 그러나 미세한 광촉매 분말(powder)은 오히려 분진으로 작용할 수 있고, 회수가 어려워 응용에 있어 상당한 제약을 받는다. 이에 상용화된 TiO$_2$ 분말이나 졸을 지지체에 코팅한 TiO$_2$ 박막으로 광촉매의 응용 범위를 점차 확대해 나가는 추세이다. (중략)

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.3
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• pp.451-456
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• 2017

Semantic segmentation, which is the most basic and complicated problem in computer vision, classifies each pixel of an image into a specific object and performs a task of specifying a label. MRF and CRF, which have been studied in the past, have been studied as effective methods for improving the accuracy of pixel level labeling. In this paper, we propose a semantic partitioning method that combines CNN, a kind of deep running, which is in the spotlight recently, and CRF, a probabilistic model. For learning and performance verification, Pascal VOC 2012 image database was used and the test was performed using arbitrary images not used for learning. As a result of the study, we showed better partitioning performance than existing semantic partitioning algorithm.

• Journal of the Korean Ceramic Society
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• v.42 no.1
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• pp.56-61
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• 2005

Highly durable photocatalytic paper containing anatase $TiO_{2}$, active carbon and ceramic fiber, which can adsorb VOCs and decompose them by photo oxidation simultaneously, was manufactured and characterized. Optimum concentration of PDADMAC to let $TiO_{2}$ adhere on the surfaces of active carbon and ceramic fiber selectively was $10\~15$ ppm in a slurry mixture for making photocatalytic paper. The thickness and basis weight of the produced catalytic paper by paper-making method were 0.4 mm and 380 $g/m^{2}$, respectively. Adsorption reaction by active carbon and photocatalytic decomposition reaction by $TiO_{2}$ were proceeded simultaneously, by which the abatement rate was found to be greatly enhanced compared to the similar environment with single adsorption reaction or single photocatalytic reaction only. The selective attachment of $TiO_{2}$ on ceramic fiber and active carbon was found to be very effective in preventing decomposition of substrate by the $TiO_{2}$ attack during exposure to UV light.

• KSBB Journal
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• v.16 no.4
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• pp.356-359
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• 2001

The ability of Pseudomonas putida to degrade toluene was studied in toluene-containing vials. The strain grows anaerobically in toluene as a sole source of carbon. When the initial toluene concentrations injected in the vial are varied, the changes of headspace toluene concentration and cell density are observed. We set a model for this vial and simulated the vial reactor using Matlab. With a variation of model parameters, simulated results were compared with the experiment.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2000.04a
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• pp.366-368
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• 2000

휘발성유기화합물질(Volatile Organic Compound ； VOCs)은 오존등 광화학옥시단트로 인한 대도시의 대기질 악화와 함께 도시환경에서 중요한 발암성 물질이거나 만성 또는 급성의 건강장해를 일으킴으로써 공중보건상에 나쁜 영향을 주는 것으로 조사되고 있다. 특히 실내 공기중의 VOCs는 건축자재, 가구, 접착제, 카페트, 흡연 및 취사행위 및 난방을 포함한 연료의 연소 등 다양한 오염원으로부터 방출되는 건으로 알려져 있다. (중략)