• Title/Summary/Keyword: indoor relative humidity

검색결과 207건 처리시간 0.028초

어린이활동공간에서의 바이오에어로졸 포집 전략 (A Suggested Air Sampling Strategy for Bioaerosols in Daycare Center Settings)

  • 조정흠;박준식;김성연;권명희;김기연;최정학;서성철
    • 한국산업보건학회지
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    • 제26권3호
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    • pp.324-333
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    • 2016
  • Objectives: We aimed to compare the sampling performance of different flow-based impactor samplers for collecting fungal spores and bacteria and to explore the association of the level of bioaerosols with activity patterns of occupants in daycare center settings. Methods: For comparison of sampling performance, two different flow-based samplers (greater than 100 L/min or not) were selected; a low flow-based sampler (one-stage Andersen sampler) and two high flow-based samplers (DUO SAS SUPER 360 sampler, BUCK bio-culture sampler). We collected airborne mold and bacteria in 30 daycare centers with various levels of contaminated air. Three repeat samplings per each sampler were performed. Mold and bacteria were grown for 96 hours at $25{\pm}1^{\circ}C$ and 48 hours at $35{\pm}1^{\circ}C$, respectively. The Andersen and SAS samplers were used for investigating the association between the level of bioaerosols and the activity patterns of occupants in daycares. Particular matters 10($PM_{10}$), temperature, and relative humidity were monitored as well. Samplings were carried out with one-hour interval from 9 to 5 O'clock. For statistical comparisons, Kruskal-Wallis test, Wilcoxon's signed rank test, and multiple regression analysis were carried out. Results: The airborne level of molds by the low flow-based sampler were significantly higher than that of high flow-based samplers (indoor, P=0.037; outdoor, P=0.041). However, no statistical difference was observed in the airborne level of bacteria by each sampler. Also the level of bioaerosols varied by the time, particularly with different activity patterns in daycare centers. The higher level of mold and bacteria were observed in play time in indoor. Similarly, the concentrations of $PM_{10}$ were significantly associated with the level of bioaerosols (P<0.05). Conclusions: Our findings indicate that the flow rate of sampler, rather than total air volume, could be able to affect the results of sampling. Also, the level of airborne mold and bacteria vary behavior patterns of occupants in indoor of daycare settings. Therefore, different samplers with other flow rate may be selected for mold or bacteria sampling, and activity patterns should be considered for bioaerosol sampling as well.

식물-바이오필터에 의한 토양수분 안정화 및 실내 공기질 향상 (Stabilization of Soil Moisture and Improvement of Indoor Air Quality by a Plant-Biofilter Integration System)

  • 이창희;최봄;천만영
    • 원예과학기술지
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    • 제33권5호
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    • pp.751-762
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    • 2015
  • 본 연구는 평면형 바이오필터를 설계하여 제작하고 이 바이오필터에 디펜바키아(Dieffenbachia amoena 'Marianne')의 식재 여부에 따라 환기 용량을 제어할 수 있는 토양 수분 안정화 정도를 측정하고 미세먼지, 휘발성 유기화합물 및 포름알데히드(HCHO)와 같은 실내공기 오염물질에 대한 바이오필터의 제거율을 비교하였다. 실험 결과 디펜바키아의 식재 여부에 관계없이 모두 일정한 상대습도, 온도 및 토양 수분 함량을 나타내었고 이 바이오필터에 식재한 디펜바키아도 정상적으로 생육하였다. 바이오필터에 의한 미세먼지 제거율을 보면, 미세먼지(PM10)와 초미세먼지(PM2.5)의 입자 수는 토양만 있는 경우 각각 30%와 2% 이상 제거되었고, 디펜바키아를 식재한 경우도 각각 40%와 4% 이상 제거되었다. 미세먼지(PM10) 무게에 따른 제거율은 토양만 있는 경우 4% 이상, 디펜바키아를 식재한 경우 20% 이상으로 나타났다. 토양만 채운 바이오필터는 xylene, ethylbenzene, toluene, total volatile organic compounds(T-VOCs)를 63% 이상 제거하였으나 benzene은 22% 이상, HCHO는 38% 이상을 제거하였다. 디펜바키아를 식재한 바이오필터는 xylene, ethylbenzene, toluene, T-VOCs를 72% 이상 제거하였고 benzene과 HCHO도 39% 이상 제거하였다. 따라서 식물과 바이오 필터를 결합한 시스템은 미세먼지의 제거보다 휘발성 유기 화합물의 제거에 대한 효과가 더 높은 것으로 나타났다. 본 연구에서 제작한 평면형 바이오필터는 실내 공기질 정화에 매우 효과가 있는 것으로 나타났으며, 식물과 바이오필터를 결합하였을 때 그 효과는 더욱 큰 것으로 확인하였다.

실내 환경 개선에 적합한 식물 선발을 위한 온도, 광도, 이산화탄소 농도에 따른 관엽식물들의 생리적 반응 (Plant Physiological Responses in Relation to Temperature, Light Intensity, and CO2 Concentration for the Selection of Efficient Foliage Plants on the Improvement of Indoor Environment)

  • 박신애;김민지;류명화;오명민;손기철
    • 원예과학기술지
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    • 제28권6호
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    • pp.928-936
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    • 2010
  • 본 연구는 관엽식물 8종을 선정하여 온도, 광도, 이산화탄소 농도에 따른 식물의 광합성률을 포함한 생리반응을 살펴 보고, 그에 따른 실내 환경 개선에 효과적인 식물을 구명하고자 실시하였다. 식물재료로는 헤데라, 벤자민 고무나무, 파키라, 스파티필름, 시서스, 디펜바키아, 스킨답서스, 싱고니움을 사용하였으며, $16^{\circ}C$$22^{\circ}C$ 온도조건하에서 광도는 PPFD 0, 25, 50, 75, 100, 150, 300, 또는 $600{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$의 수준으로, 이산화탄소 농도는 0, 50, 100, 200, 400, 700, 또는 $1,000{\mu}molCO_2{\cdot}mol^{-1}$의 수준으로 조절하여 휴대용 광합성 측정기(Li-6400, Li Cor, USA)로 관엽식물들의 광합성 효율과 증산율을 측정하였다. 광도, 엽육내 이산화탄소 농도 변화, 그리고 온도에 따른 관엽식물들의 광합성 반응은 매우 다양했다. 약광(PPFD $0-100{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$)에서의 광합성 능력을 나타내는 순양자수율은 디펜바키아를 제외한 대부분의 종에서 높게 나타났으며, 고광(PPFD $200-600{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$)에서는 헤데라, 벤자민 고무나무, 파키라, 스파티필름이 높은 광합성능력을 나타내었다. 이산화탄소를 고정하는 암반응과 관련된 탄소고정효율은 시서스와 싱고니움을 제외한 6종의 관엽식물들에서 비교적 높게 나타났다. 고농도의 이산화탄소에서 광합성률이 높은 식물은 헤데라와 스파티필름이었으며, $22^{\circ}C$에서 자란 벤자민 고무나무와 파키라도 높은 광합성률을 보였다. 한편, 헤데라, 스파티필름은 증산율도 높게 나타났다. 따라서 저광, 고농도의 이산화탄소, 낮은 상대습도가 특징인 일반 가정이나 사무실 같은 실내 환경을 고려했을 때 헤데라, 벤자민 고무나무, 파키라, 스파티필름 등을 이용하는 것이 실내 환경 개선에 효과적이라고 판단되었다.

가습 주기에 따른 벽면형 식물바이오필터의 토양 수분 안정화 및 실내공기질 정화 (Stabilizing Soil Moisture and Indoor Air Quality Purification in a Wall-typed Botanical Biofiltration System Controlled by Humidifying Cycle)

  • 이창희;최봄;천만영
    • 원예과학기술지
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    • 제33권4호
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    • pp.605-617
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    • 2015
  • 본 연구의 최종 목표는 실내의 공간과 식물바이오필터의 규모에 따라 실내공기 오염물질을 정화할 수 있는 식물 녹화와 자동관수 그리고 생물학적 여과 기능을 통합한 식물바이오필터 시스템의 개발이다. 본 연구는 가습 주기에 따른 벽면형(수직형) 식물바이오필터내 공기 흐름의 특성에 대한 안정성과 미세먼지 제거율을 비교하고, 이 식물바이오필터에 의한 휘발성 유기화합물의 제거율을 조사하기 위해 수행하였다. 본 실험에 사용된 식물바이오필터는 실내 공간 활용에 적합하도록 물펌프, 물탱크, 송풍기, 가습장치, 그리고 다층구조의 식물 식재 공간을 일체형으로 설계하였다. 실험 결과, 물펌프에 의해 작동하는 세 가지 다른 가습 주기 처리에 관계없이 식물바이오필터의 상대습도, 온도, 그리고 토양 수분 함량은 안정된 값을 나타내었다. 토양 수분 함량은 모든 가습 주기 처리에서 27.1-29.7%의 범위에서 안정적으로 유지하였으며, 특히 15분 작동 45분 작동 중지의 가습 주기를 120시간 동안 처리하여 $29.0{\pm}0.2%$의 평균 토양 수분 함량을 유지하면서 가장 수평적인 일차회귀식(y = 0.0008x + 29.09)을 보여주었다. 가습 주기에 따라 식물바이오필터를 통과한 미세먼지(PM10)와 초미세먼지(PM2.5) 입자 수에 대한 제거율(RE)은 각각 82.7-89.7%와 65.4-73.0% 범위에 있었고, PM10의 무게에 대한 RE는 58.1-78.9%의 범위에 있었다. 식물바이오필터를 통과한 자일렌, 에틸벤젠, 총 휘발성 유기화합물, 톨루엔의 RE는 71.3-75.5%의 범위에 있었으나, 벤젠과 포름알데히드의 RE는 각각 39.7%와 44.9%로 나타났다. 따라서 실내식물을 식재할 수 있는 본 벽면형 식물바이오필터는 실내 공기 정화에 매우 효과가 있는 것으로 확인하였다.

Test of Larvicidal Effect of Some Commercial Natural Products on Lepidoptran Plutella xylostella and Spodoptera litura Larvae

  • Jeong, Hyung-Uk;Im, Hyun-Hwak;Chang, Sung-Kwon;Paik, Chae-Hoon;Han, Tae-Ho;Kim, In-Seon;Kim, Ik-Soo
    • International Journal of Industrial Entomology and Biomaterials
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    • 제15권1호
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    • pp.87-91
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    • 2007
  • A diverse kind of environment-friendly agricultural materials(EFAM) for the control of insect pests is on the market. These EFAMs are a part of essential sources for the accomplishment of successful, sustainable, and environment-friendly agriculture. Thus, accurate information of these EFAMs is one that required for the success of environment-friendly agriculture, but, in reality, still appropriate information is absolutely in shortage. In this study, we, therefore, tested the efficacy of commercial EFAMs against two lepidopteran insect larvae, the diamondback moth Plutella xylostella(Lepidoptera: plutellidae) and the tobacco cutworm Spodoptera litura(Lepidoptera: Noctuidae). After the two insect pests were successfully stabilized in indoor environment the larvicidal activity was tested at $24{\pm}1^{\circ}C$, relative humidity(RH) of $60{\pm}5%$, and a photoperiod of 16L:8D, and mortality was determined 48 hrs after EFAMs are treated. The EFAMs that showed more than 90% of larvicidal activity were each six among 16 against both P. xylostella and S. litura and only three of them showed consistent larvicidal activity against both species, signifying species specificity of EFAMs and importance of selection of proper EFAMs depending on target insect pest.

가스상 대기오염물질에 의한 종이 기록물의 가속열화 특성 연구 (Studies on the Accelerated Aging Characteristics of Paper Records by Gaseous Air Pollutants)

  • 정소윤;전수연;백소라;정현석;이진희;김형진
    • 펄프종이기술
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    • 제47권4호
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    • pp.151-159
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    • 2015
  • Paper records were generally degraded by some factors from atmospheric environments, like temperature, relative humidity or air pollutants. In this study, the degradation behavior of paper records by single or mixed gases of $NO_2$, $SO_2$, HCHO and TVOC was evaluated. The mechanical, optical and chemical properties of 4 kinds of paper (acid and neutral-based printing paper, traditional Hanji, and filter paper) were directly and indirectly affected by gaseous harmful materials. The brightness and $L^*$ value in all papers were slightly increased by accelerated aging under gaseous HCHO and TVOCs, but highly decreased by conditions under gases $NO_2$ and $SO_2$. The optical properties of paper records were most vulnerable in acid-based paper and high stable in filter paper and traditional Hanji by air pollutant degradation. The aging treatments under mixed gas pollutants including $NO_2$ resulted in decrease of physical, mechanical and optical properties of paper, so it was supposed that the concentration of $NO_2$ gas would be strictly controlled for optimum indoor air quality management in domestic storage centers for paper records.

톱밥 절감형 돈분 슬러리 연속 퇴비화 공정 연구 (Study on the Continuous Composting Process to Reduce the Use of Bulking Agent in Pig Slurry)

  • 류종원
    • 한국축산시설환경학회지
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    • 제13권2호
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    • pp.121-128
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    • 2007
  • 축산분뇨와 톱밥을 혼합하여 수분조절을 한 후 발효조에 투입하는 방식이 아닌 발효상에 미리 투입된 톱밥위에 축산분뇨를 살포하면서 교반처리하여 발효증발 처리하는 시스템을 이용하여 퇴비 발효층의 온도, 수분함량, 수분수지, 퇴비의 비료성분을 연구하였다. 1. 본 처리공정은 과다한 수분을 신속하게 침출수 강제배출 방식으로 배출하여 슬러리 투입분뇨의 함수율이 높더라도 수분증발이 이루어지고 발효상 함수율은 $65{\sim}73%$ 전후로 유지되었다. 2. 연속퇴비화 과정에서 시험기간 중에 10.6% 정도의 침출수가 발생되었다. 또한 5개월 가동 기간 동안 톱밥 $1m^3$ 투입 당 $3.16m^3$의 돈분슬러리 처리가 가능하였다. 3. 침출여과액은 오염물질농도가 낮아져 투입분뇨 대비 BOD는 86.5%, SS은 96.2% 저감되었다. 4. 퇴비사의 미기상 분석결과 상대습도는 낮 시간을 제외한 야간시간에는 $80{\sim}100%$로서 높았다. 퇴비사의 습도가 높아지면 퇴비화 과정 중 수분증발 효율이 저하의 원인이 될 것으로 사료된다.

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밀폐형 돈사 작업장의 전체 환기율이 가스상 오염물질 노출 농도 변화에 미치는 영향 (Effect of General Ventilation Rate on Concentrations of Gaseous Pollutants Emitted from Enclosed Pig Building)

  • 김기연;서성철;최정학
    • 한국산업보건학회지
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    • 제24권1호
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    • pp.46-51
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    • 2014
  • Objectives: The principal aim of this study was to compare the concentrations of gaseous pollutants emitted in enclosed pig buildings between different rates of general ventilation and determine the variations in the patterns of gaseous pollutants as affected by ventilation rate. Materials and Methods: The experiment was performed in the growing/finishing room($20.0m{\times}12.0m{\times}3.0m$) of a pig confinement building located on the experimental farm of Seoul National University. The conditions of the general ventilation rate for three treatments were 30%($4.12m^3s^{-1}$), 50%($6.87m^3s^{-1}$) and 70%($9.61m^3s^{-1}$). The data presented in the study were collected overa total of 45 days, 15 days for each of the three treatments from March to May 2011. A total of six air samplings were taken at 1.5m above the floor of the pig building. The environmental agents measured in the pig building were ammonia, hydrogen sulfide and odor concentration index for gaseous pollutants with temperature and hydrogen sulfide for thermal factors. Results: There were significant differences in the ammonia and odor concentration index in the pig building among the three general ventilation rate conditions(p<0.05), whereas hydrogen sulfide did not show a significant difference among three conditions of general ventilation rate(p>0.05). As the general ventilation rate applied to the pig building increases, it appears that all the indoor environmental agents measured in this study simultaneously decrease. Conclusions: The gaseous pollutants significantly affected by the general ventilation rate in pig building were ammonia and odor concentration index(p<0.05). However, it was found that hydrogen sulfide and thermal factors, temperature and relative humidity were not influenced significantly by variation in the general ventilation rate.

Degradation of Chlorinated Hydrocarbons via a Light-Emitting Diode Derived Photocatalyst

  • Jo, Wan-Kuen;Lee, Joon Yeob
    • Environmental Engineering Research
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    • 제18권1호
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    • pp.21-28
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    • 2013
  • In this study, the applicability of visible light-emitting-diodes (LEDs) to the photocatalytic degradation of indoor-level trichloroethylene (TCE) and perchloroethylene (PCE) over N-doped $TiO_2$ (N-$TiO_2$) was examined under a range of operational conditions. The N-$TiO_2$ photocatalyst was calcined at $650^{\circ}C$ (labeled N-650) showed the lowest degradation efficiencies for TCE and PCE, while the N-$TiO_2$ photocatalysts calcined at $350^{\circ}C$, $450^{\circ}C$, and $550^{\circ}C$ (labeled as N-350, N-450, and N-550, respectively) exhibited similar or slightly different degradation efficiencies to those of TCE and PCE. These results were supported by the X-ray diffraction patterns of N-350, N-450, N-550, and N-650. The respective average degradation efficiencies for TCE and PCE were 96% and 77% for the 8-W lamp/N-$TiO_2$ system, 32% and 20% for the violet LED/N-$TiO_2$ system, and ~0% and 4% for the blue LED/N-$TiO_2$ system. However, the normalized photocatalytic degradation efficiencies for TCE and PCE for the violet LED-irradiated N-$TiO_2$ system were higher than those from the 8-W fluorescent daylight lamp-irradiated N-$TiO_2$ system. Although the difference was not substantial, the degradation efficiencies exhibited a decreasing trend with increasing input concentrations. The degradation efficiencies for TCE and PCE decreased with increasing air flow rates. In general, the degradation efficiencies for both target compounds decreased as relative humidity increased. Consequently, it was indicated that violet LEDs can be utilized as energy-efficient light sources for the photocatalytic degradation of TCE and PCE, if operational conditions of N-$TiO_2$ photocatalytic system are optimized.

환기회수 및 부하율 변화에 따른 휘발성유기화합물 농도 감쇠 예측에 관한 연구 (Prediction of the Concentration Decay of Volatile Organic Compounds under Different Air Change Rates and Loading Factor Conditions)

  • 방승기;손장열;안병욱
    • 설비공학논문집
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    • 제17권6호
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    • pp.505-513
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    • 2005
  • We measured the time-dependent concentration of VOCs emitted from Ondol floor, furniture, and the wall made of various building materials. After obtaining results from the previous measurement, we developed the estimation equations of the concentration decay, and obtained the estimated graphs for the concentration decay under different air change rates and loading factor conditions by using the estimated equations. We conducted our tests by applying our measurements to real residences for 110 days in the case of furniture and for 40 days in the case of the floor. We also conducted experiments in the cases of various wall materials for 7 days which totaled 10 times. We used the GC/FID for experiments for real residences accord-ing to the specified procedures of the NIOSH 1501, and carried out experiments for wall materials according to the specified procedures of the ASTM 5116-97. When conducting experiments for wall materials, we set the temperature and relative humidity at $23^{\circ}C$ and $50\%$, respectively. We also set the air change rate and loading factor at 0.7/h and $1.617 m^2/m^3$, respectively. Our results showed that it is possible to predict proplrly the time-dependent concentration decay of VOCs by using logarithmic functions in both cases of experiments for real residences and for wall materials. Furthermore, we found that the concentration decay rate of VOCs increased rapidly as the air exchange rate increased while the concentration decay rate decreased as the loading factor increased.