Filter and microbalance sensitivity in measuring fine particulate matter mass is greatly influenced by particulate properties and environmental factors. Temperature and humidity control inside a measuring chamber with a microbalance, and neutralization of static charges on filters are essential for consistent filter weighing. Commercial weighing chambers are expensive with a unit price of tens of millions won. This study developed an inexpensive weighing chamber for weighing fine particulate matter and evaluatedits weighing performance. A microbalance with 1 μg precision was used to measure the weight of a filter. The microbalance was set in a transparent acrylic enclosure (100 x 60 x 65 cm3) equipped with temperature and humidity control equipments. Weighing performance of the chamber was examined using Teflon filters with or without different particulate sample types. Temperature and humidity were maintained at approximately 23.2±1.2 ℃ and 36.2±1.8℃ for 8 days, respectively.

The technology for sludge drying using a microwave is a primary process in producing solid refuse fuel in the waste-toresource process. In this paper, the drying efficiency is improved by investigating chamber types such as square and circle with various mechanical conditions such as the magnetron power, the height of microwave irradiation, and the sludge thickness. In identical conditions, the moisture content was generally uniform in the circle chamber due to the uniform distribution of microwave irradiation, and the drying efficiency was higher in the circle chamber compared to the square chamber. In the case of the circle chamber, the drying rate was increased by more than 30% and the energy for sludge drying 507.9 kcal/kg of water was reduced. Hence, the application of a circle chamber should save energy consumption in sludge drying.

현대 사회는 산업사회의 발달과 도시화 현상에 의해 인구분포의 불균형을 초래하였고 이러한 도시인구의 집중으로 도시 외곽에 속해있던 부도심 지역이 도시의 중심부로 편입되었고 매립지 인근 지역까지 도시화가 확장되었다. 그 결과 도시폐기물의 발생량은 급격히 증가하였고 이러한 도시 폐기물처리에 대한 관심과 대책이 필요하게 되었다. 매립지에서 발생되는 매립가스(LFG : Landfill Gas)는 악취 등 주변지역 대기환경 오염의 원인이 되고 안정화 및 사후관리에 지장을 주고 있다. 매립가스는 메탄가스와 이산화탄소, 악취유발가스, 기타 유해가스들로 구성되어 있으며, 이러한 매립가스의 적정처리방안이 강구되어야 한다. 최근 이러한 매립가스의 악취물질의 방출을 근본적으로 저감시킬 수 있는 포집 시스템이 매우 중요하게 거론되고 있으며 그 중 매립가스 자원화 시설은 매립가스 활용화 및 매립가스로 인한 악취문제를 해결하기 위한 수단으로 매립가스를 강제 수집 및 포집하여 연소시킴으로서 악취로 인한 대기오염 문제를 줄일 수 있는 시스템으로 활용하고 있다. 본 연구에서는 국내 매립지의 악취(가스)수집 및 포집을 위하여 수집/포집관로 규모 및 형태에 따른 추가설치기능방안에 대한 매립지 모형챔버 실험을 실시하고 이를 바탕으로 모형 및 현장에 대한 유체역학적 연구를 실시하고자 하였다. 또한 전산유체역학 해석을 통하여 적용 평가에 대한 정상적인 기류해석을 통해 기능성을 파악하고 이에대한 해석을 위해 시뮬레이션을 도입하였다. 연구결과 모형챔버를 통한 기존의 수직포집정에서의 매립가스 포집효율은 36.3%로 나타났고 기존의 수직포집정에 추가 포집정을 설치한 후 포집효율은 46.2%로 증가하였다. 모형챔버 실험에서 강제로 매립가스를 추출하지 않은점을 감안할 때 강제 수집 및 포집을 실시 할 경우 포집효율 약65%의 수준을 보일것으로 사료된다.

Passive sampler is a simple and cost-effective measuring equipment for ambient and indoor air pollution. We studied the performance of a short term (1 hour mean concentration) ozone passive sampler which was coated with a colorant (indigo carmine) to a filter substrate. Acetone and sulfamic acid added ozone passive sampler was investigated to measure short term mean ozone concentration. Ozone response and interference of criteria air pollutant(SO2, NO2, CO) on a short term ozone passive sampler was tested through experimental chamber. The results show sulfamic acid added passive ozone sampler have good response in ozone exposure. Interference of NO2 gas is larger than other two criteria gases.

The number of cases exceeding environmental standards of atmospheric ozone in the major cities in Korea has steadily increased during the past decades. In order to understand and analyze the atmospheric reactions in the atmosphere, especially the secondary photochemical reactions, smog chambers studies have been performed very actively by many research groups worldwide. However, these studies have focused on the mechanism of photochemical reactions in high concentration conditions, not at the ambient levels. Therefore, in-depth studies in these conditions are essentially needed to realize exact mechanism in the atmosphere near the earth surface, especially at Korean atmospheric conditions. In this experiment, the mechanism of photochemical smog was examined through a comparative experiment of smog chambers under sun light and black light conditions. The results of our study indicated that concentrations of ozone, aldehyde, and PAN increased as the radiation of light source increases. Photochemical reaction patterns can be considered quite similar for both black light and sun light experiments. Based on our experiments using toluene as a reactant which is present at significant high levels in ambient air relative to other VOCs, it was found that toluene could contribute notably to oxidize NO to NO2, this reaction can eventually generate some other photochemical oxidants such as ozone, aldehyde, and PAN. The results of simulation and experiments generally showed a good agreement quite well except for the case of O3. The restriction of oxidization of NO to NO2 seems to cause this difference, which is mainly from the reaction of peroxy radical itself and other reactants in the real gas.