• 한국환경보건학회지
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• 제50권2호
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• pp.83-92
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• 2024

Background: In this study, we investigate the rapid increase in environmental odors and notable rise in civil complaints near Dorim Stream in the Gwanak-gu area of Seoul. Objectives: This study aims to identify the causal compounds responsible for environmental odors in the Dorim Stream and investigate the structural characteristics of the stream that influence odor generation. Methods: The research methodology involved setting up 41 sampling points, selecting panels for direct sensory evaluation to assess odor intensity, measuring dissolved oxygen and hydrogen sulfide concentrations, and using all-in-one low-temperature desorption gas chromatography (ATD-GC) and thermal desorption-gas chromatography-mass spectrometry (TD-GC/MS) analysis to identify odor-causing compounds. Results: The evaluation of Dorim Stream revealed that in areas with complete meandering, there were lower dissolved oxygen levels (4.5±2.67 mg/L) and higher odor intensity (4.0±0.92), while in partially meandering sections, higher dissolved oxygen levels (7.8±1.15 mg/L) and lower odor intensity (2.8±1.06) were observed. Hydrogen sulfide levels measured with sensors increased with higher temperatures, especially in the afternoon hours (12:00~14:00). Acetaldehyde was the dominant odor compound detected in both the Bonglim Bridge (0.4 ppm) area and Guro Bridge area (0.867 ppm), with concentrations more than twice as high near Guro Bridge. Odor-causing compounds identified by TD-GC/MS indicated a pungent, sulfurous odor in the Guro Bridge area and a musty odor in the Bonglim Bridge area. Conclusions: This study categorizes and analyzes the sources of odor in Dorim Stream in Seoul based on meandering patterns and the distribution of sewage facilities, highlighting the potential odor issues associated with combined sewage systems and sewer junctions and suggesting policy improvements.

• 센서학회지
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• 제25권3호
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• pp.161-172
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• 2016

The use of a chemical sensor array can help discriminate between chemicals when comparing one sample with another. The ability to classify pattern characteristics from relatively small pieces of information has led to growing interest in methods of sensor recognition. A variety of pattern recognition algorithms, including the adaptive radial basis function network (RBFN), may be applicable to gas and/ or odor classification. In this paper, we provide a broad review of approaches for various types of gas and/or odor identification techniques based on RBFN and drift compensation techniques caused by sensor poisoning and aging.

• 한국환경보건학회지
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• 제43권6호
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• pp.457-466
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• 2017

Objectives: This study was carried out to investigate the characteristics of volatile organic compounds (VOCs) emitted from sewerage facilities such as a sanitary sewers, outlets, and catch basins. In addition, the dominant malodorous VOCs among the compounds in this study were studied. Methods: Waste gas samples were collected at 27 points in a sanitary sewer in commercial and residental areas. The concentrations of seven volatile organic compounds, including benzene and toluene, in the samples were analyzed by gas chromatograph mass spectrophotometer (GC/MS). Odor concentrations were estimated using the concentration data of the VOCs and each compound's threshold limit value. Results: As a result, it appeared that the average concentration of total observed data for acetaldehyde was 15.98 ppb and benzene 1.87 ppb, toluene 82.31 ppb, ethyl benzene 63.12 ppb, m+p-xylene 15.66 ppb, oxylene 18.73 ppb, and styrene 4.39 ppb. VOC concentrations in the commercial area were higher than those in the residential area. VOC concentrations of waste gas emitted from sewer lines was also higher than those at the outlet and in the catch basins. It was estimated that the main malodorous VOC among the seven VOCs was acetaldehyde. Conclusions: As there is little data on VOC concentrations inside sewer facilities in Korea, these data will be helpful for estimating impact assessment of VOCs and establishing a counter-plan for the abatement of VOCs from sewer facilities in the future.

• 한국입자에어로졸학회지
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• 제17권4호
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• pp.115-123
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• 2021

The emission gas from meat grilled restaurants has unpleasant odor and sticky particulate matters (PM) in form of oil mist. This affects the residents living nearby. In oder to decrease the odor and PM, electrostatic precipitators (ESP) were installed at several restaurants by support of Seoul metropolitan government and emission characteristics of PM and odor were investigated. The removal efficiency of odor and PM at before- and after-ESP was that total hydrocarbon (THC), NH₃, H₂S, acetaldehyde, butyraldehyde were not much decreased. Total suspended particles (TSP) emitted from the vent was below the value of 7 mg/m³ regardless of the concentration of before-ESP and removal efficiency was in the range of 64 ~ 86%. The ratio of PM_1.0 to PM₁₀ of emission gas was over 0.9. So it was revealed that most PM of emission gas was PM1.0. The PM concentration in the air of the street near the vent was higher than another street due to the emission gas and the PM of indoor air of restaurant grilling meats was measured very high compared to outdoor air. So it needs more powerful ventilation of indoor air.

• 환경위생공학
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• 제11권1호
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• pp.9-15
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• 1996

The purpose of this study was to evaluate the decomposition efficiency of $NH_3$ odor gas using high frequency surface discharge body. The results from this study are as follows; 1, Voltage and frequency of electric elements have effects on removal of $NH_3$ odor. The higher these two elements were set up, the more efficiently deodorizing processing worked. In this experiment, the optimum voltage and frequency applicable were observed around AC 6.0 kVp-p and 24.0 kHz respectively. 2. The temperature, humidity and residence time were observed strong variables for NH$_3$ removal process. Its performance had limits at high temperature and humidity conditions. The longer the residence time continued, the more efficiently deodorization process worked. The experimental results showed that the deodorization was efficiently processed under such conditions as $30.0^{\circ}C$ in temperature, 60rh% in humidity and 0.3 sec in residence time. 3. It was observed that in deodorization experiment, $NH_3$ odor gas was perfectly decomposed under the concentration condition below 15.0ppm. Moreover it was considered as economic and practical in terms of maintenance cost when compared with other deodorization methods.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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• pp.2540-2543
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• 2008

Liquid crystal displays (LCD's) are continuously coated with some chemicals in the clean room of a factory. Spreading of these chemicals is causing serious problems both in controlling clean room quality as well as to the workers inside the factory. It is required to alleviate or properly control the offensive odor which is mainly composed of propylene glycol mono ethyl acetate, novolak resin and photo active compound. The control strategy employed is to bleed the offensive odor gas out the clean room. A full scale 3D CFD model was created with anisotropic porous media, chemical species transport with no volumetric reaction, and thermal diffusion with propane gas (tracer gas) to simulate the odor spreading. A segregated implicit solver with standard k-$\varepsilon$ model is employed. The detailed CFD analysis made it possible to develop an effective method of ventilating the coater room and optimizing their capacities.

• 청정기술
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• 제23권1호
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• pp.34-41
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• 2017

스크러버는 적정한 처리효율을 유지하기 위하여 세정수를 지속적으로 교체해 주어야 한다. 하지만 화학업종 대부분은 폐수 처리시설이 없어 스크러버 세정수를 위탁 처리하고 있으며, 처리비용 때문에 자주 교체해 주지 못하는 실정이다. 이로 인해 악취배출허용기준을 초과하거나 배출구 농도가 더 높아지는 역전현상을 유발하기도 한다. 이에 세정수를 자체 정화 하여 사용할 수 있도록 여과와 흡착 공정으로 구성된 세정수 처리시스템을 개발하였다. 세정수 처리 시스템은 화학업종 두 개 스크러버를 대상으로 적용하였으며, 세정수 수질 상태와 악취저감 효과를 평가하였다. 세정수 처리 시스템 적용 결과 50% 이상의 수질개선 효과와 20% 이상의 악취개선 효과를 확인 하였으며, 기존 운영대비 40%의 비용절감 효과도 기대할 수 있었다.

• 한국균학회지
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• 제40권4호
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• pp.254-257
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• 2012

경기도 지방의 된장 시료로부터 악취감소 효과 미생물 중에서 효모가 분리되었으며 rDNA염기서열분석에 의하여 Pichia farinosa로 동정 되었다. 공시균주 P. farinosa NASS-2로 대량배양조건 확립 및 미생물처리제를 제조하였다. 분리한 효모로 제조한 악취저감효과 처리제의 실내 시험결과 돈분에 미생물제를 처리하고 15일 경과 후 악취가스 감소율을 조사한 결과, 암모니아가스($NH_3$ gas)는 처리 전 19.49 ppm에서 처리 후는 1.38 ppm으로, 황화수소가스($H_2S$ gas)는 처리 전 5.89 ppb에서 처리 후는 0.32 ppb으로 감소하는 효과를 나타내었다. 일반적으로 박테리아가 악취저감효과 미생물로 사용되고 있으나 본 연구에서 사용한 된장에서 분리한 효모 특히 산막효모인 P. farinosa NASS-2의 악취효과(암모니아가스, 황화수소 가스)는 처음 보고이다.

• Journal of Biosystems Engineering
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• 제29권2호
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• pp.151-158
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• 2004

This research was conducted to study the offensive odor adhesion efficiency of filter bed materials using the experimental column that was designed and constructed in this work. The offensive odor adhesion experiment was conducted using mixture of high physical adhesion efficiency material, and the fixity of deodorization microorganism of selected filter bed material was tested using ammonia exclude microorganism A4-2 and sulfur oxidation microorganism S5-5.2 those were cultured at the Agricultural Chemical Department of Chungnam National University, and deodorization efficiency of selected filter bed material mixture was tested. Followings are summary of these tests results. 1) Amount of elimination of the offensive odor gas ammonia and hydrogen sulfide per unit volume were 0.054 and 0.016 $\ell$/㎤ in rice hull, 0.01 and 0.004 $\ell$/㎤ in rice straw, 0.158 and 0.01 $\ell$/㎤ in coconut, 0.014 and 0.02 $\ell$/㎤ in perlite, 0.004 and 0.003 $\ell$/㎤ in high road ball, and 0.112 and 0.015 $\ell$/㎤ chaff of pine, respectively. 2) Amount of elimination of offensive odor gas of ammonia and hydrogen sulfide per unit vloume were 0.079 and 0.016 $\ell$/㎤ in mixture 1, 0.045 and 0.014 $\ell$/㎤ in mixture 2, 0.123 and 0.017 $\ell$/㎤ in mixture 3, 0.055 and 0.016 $\ell$/㎤ in mixture 4, 0.031 and 0.015 $\ell$/㎤ in mixture 5, and 0.111 and 0.020 $\ell$/㎤ in mixture 6, respectively. 3) The offensive odor elimination microoraganism inoculated to the mixture of chaff of pine (70%) and pert (30%) showed the elimination efficiency of 99.06% and 96.61% against the ammonia and hydrongen sulfide, respectively, during 24 hours period.

• 한국산업보건학회지
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• 제19권2호
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• pp.102-112
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• 2009

The greatest concern of vapor/gas respirators is when to exchange chemical cartridges, but it is very difficult to estimate the breakthrough time of them in the workplace spot due to so many factors influencing on breakthrough. There needs to study on estimating cartridge exchange period available practically in the spot, even if it is not precise. In the previous study, authors suggested the method on estimating service-life of chemical cartridges using cartridges discarded after use. This followed study was to estimate exchange period for chemical cartridges using comparison of concentrations between Korean Occupational Exposure Limits (KOELs) and odor thresholds of chemicals. Chemicals were divided into four groups, I, II, III and IV groups. Group I chemicals are relatively safe if cartridges are just or slightly delayed exchanged when smelling since odor thresholds were less than 0.5 times KOELs. Odor threshold of Group II chemicals are 0.5~2.0 times KOELs and potentially hazardous if cartridges are exchanged when smelling. Those chemicals should be conducted program on estimating service-life of cartridges, which was just previously published (J Kor Soc Occup Environ Hyg 2008;18(3) 204-215). Group III chemicals (odor thresholds are more than 2.0 times KOELs) and Group IV chemicals (odorless or no data for smelling) must be performed the above mentioned program before cartridges. Even if this method on cartridge exchange using odor threshold is practically widely used in the workplace spot in the present, program on estimating service-life of cartridges is recommended for all chemicals to reduce potentially hazards.