The concern of fine particle (PM2.5) management of outdoor environments has been increasing due to its exposure and related health effects in Korea. As a result, PM2.5 standard in atmosphere environment was regulated in 2015. On the other hand, indoor PM2.5 standard has been required because most people spent their times in indoor environments. In this study, we measured the PM2.5 and PM10 concentrations both indoor and outdoor environments of public-use facilities such as underground stations, underground shopping centers, and nurseries for 24 hour with filter-weighing method in Seoul and Daegu. Measurement duration was from March to April in 2014 during the Asian dust period. At all measurements, indoor to outdoor (I/O) concentration ratios exceeded 1 except 1 day nursery in Daegu in spite of Asian dust period. The ratios of PM2.5 to PM10 concentrations ranged from 0.63 to 0.75 in indoor environments, and from 0.63 to 0.82 in outdoor, indicating that PM2.5 should be carefully managed in indoor environments as well as outdoor atmosphere.
Abstract Dielectric barrier discharge (DBD) in air, which has been established for the production of large quantities of ozone, is more recently being applied to a wider range of aftertreatment processes for HAPs (hazardous air pollutants). Although DBD has high electron density and energy, its potential use as precharging nano and submicron sized particles, is not known. In this work, we measured V‐I (voltage‐current) characteristics of DBD and estimated the collection efficiency of particles with bimodal distribution by DBD type 2‐stage ESP (electrostatic precipitator). To examine the particle collection with various applied voltage waveforms of DBD, nano size particles of NaCl (20∼100 nm) and DOS (50∼800 nm) were generated by an electrical tube furnace and an atomizer, respectively. Particle collection efficiencies of all the cases increased with increase of DBD electric power that the results corresponded to product of V by I whose magnitudes were the largest in triangular voltage waveform.
This study investigated the effect of May 31, 2022 Miryang wildfire on fine particle concentrations in Busan and Gimhae, which are neighboring urban areas. In addition, fine particle characteristics and air pollution concentrations were investigated in Miryang, where haze occurred. The Miryang city wildfire that occurred on May 31, 2022, at 0925 LST, was driven by strong north winds and increased fine particle concentrations in Dongsangdong and Jangyoodong, Gimhae City, which are approximately 35 km to the southeast and south, respectively, of the wildfire occurrence site. Furthermore, the fine particle concentration in Myeongjidong, which is approximately 50 km south-southeast of the wildfire site, exhibited a temporary increase at 1400 LST owing to the effects of wildfire smoke. On the morning of June 1, the day after the fire, the Miryang area had very bad visibility because of the smoke from the fire. Therefore the PM10 and PM2.5 concentrations in Naeildong, 3 km south of the wildfire site, were 276 μg/㎥ and 222 μg/㎥, respectively, at 1200 LST. In addition, the gases O3, CO, and SO2 showed high concentrations at the time of haze generation. This study provides insights into policy making in response to the rapid increase in fine dust when wildfire occurs near cities.
This study investigated the weather conditions, fine particle concentration, and ion components in PM2.5 when two cold fronts passed through Busan in succession on February 1 and 2, 2021. A analysis of the surface weather chart, AWS, and backward trajectory revealed that the first cold front passed through the Busan at 0900 LST on February 1, 2021, with the second cold front arriving at 0100 LST on February 2, 2021. According to the PM10 concentration of the KMA, the timing of the cold front passage had a close relationship with the occurrence of the highest concentration of fine particles. The transport time of the cold front from Baengnyeongdo to Mt. Gudeok was approximately 11 hours . The PM10 and PM2.5 concentrations in Busan started to increase after the first cold front had passed, and the maximum concentration occurred two hours after the second cold front passed. The SO4 2-, NO3 -, and NH4 + concentration in PM2.5 started to increase from 1100 to 1200 LST on February 1, after the first cold front passed, and peaked at 0100 LST to 0300 LST on February 2. However, the highest Ca2+ concentration was recorded 2-3 hours after the second cold front had passed.
This research investigated the characteristics of fine particle concentration and ionic elements of PM2.5 during sea breeze occurrences during summertime in Busan. The PM10 and PM2.5 concentrations of summertime sea breeze occurrence days in Busan were 46.5 ㎍/㎥ and 34.9 ㎍/㎥, respectively. The PM10 and PM2.5 concentrations of summertime non-sea breeze occurrence days in Busan were 25.3 ㎍/㎥ and 14.3 ㎍/㎥, respectively. The PM2.5/PM10 ratios of sea breeze occurrence days and non-sea breeze occurrence days were 0.74 and 0.55, respectively. The SO4 2-, NH4 +, and NO3 - concentrations in PM2.5 of sea breeze occurrence days were 9.20 ㎍/㎥, 4.26 ㎍/㎥, and 3.18 ㎍/㎥ respectively. The sulfur oxidation ratio (SOR) and nitrogen oxidation ratio (NOR) of sea breeze occurrence days were 0.33 and 0.05, respectively. These results indicated that understanding the fine particle concentration and ionic elements of PM2.5 during sea breeze summertime conditions can provide insights useful for establishing a control strategy of urban air quality.
The study was conducted to evaluate the penetration performance of Surface Protection Material(SPM) according to the particle size distribution of fine aggregate. The fine three types of aggregates were used, and the amounts of SPM were applied 0.13, 0.25, 0.36, and 0.51 kg/㎡. Test results indicated that the penetration depth of SPM were improved with increasing the amounts of application of SPM. And The penetration depth of SPM were improved with increasing the percentage of passing weight of size of sieve between 0 and 1.25mm.
Polluting gases emitted from industrial sites take compound forms consisting of gaseous and particulate phases. Localization of PTFE membrane filters has thus been initiated to remove particulate materials and mercury, which is a heavy and hazardous metallic element. More specifically, a PTFE membrane filter was fabricated by thermal laminating technology to vary porosity on the filter surface for removal of particulate materials thereon. Optimized equi-biaxial stretching ratio control enables minimization of large-size pore formation with an average pore size of 0.58 μm and improved air permeability of 8.03 cm3/cm2/sec. Various adsorbents were tested for removal of mercury vapor by surface treatment of the PTFE membrane filter. The filter’s surface was further altered using functional amine group compounds: one composed of silane coupling agent (APTMS) was found suitable as a mercury adsorbent. When ACF with a large surface area was used as support material, mercury removal efficiency increased threefold to 0.162 mg/g-ACF. Furthermore, the developed PTFE membrane filter was tested in its capacity of differential pressure and filtering efficiency using a pilot scale particulate removal unit. Stable and consistent differential pressure was maintained during long-term operation and less frequent periods of filter shutdown due to pores filling with 99.96% of particulate removal efficiency, which was more than satisfactory filtration efficiency.
This research investigates the characteristics of metallic and ionic elements in PM10 and PM2.5 on haze day and non-haze day in Busan. PM10 concentration on haze day and non-haze day were 85.75 and 33.52 ㎍/m³ , respectively, and PM2.5 on haze day and non-haze day were 68.24 and 23.86 ㎍/m³ , respectively. Contribution rate of total inorganic water-soluble ion to PM10 mass on haze day and non haze day were 58.2% and 61.5%, respectively, and contribution rate of total water-soluble ion to PM2.5 mass on haze day and non haze day were 58.7% and 64.7%, respectively. Also, contribution rate of secondary ion to PM10 mass on haze day and non haze day were 52.1% and 47.5%, respectively, and contribution rate of secondary ion to PM2.5 mass on haze day and non haze day were 54.4% and 53.6%, respectively. AC (anion equivalents)/CE (cation equivalents) ratio of PM10 mass on haze day and non haze day were 1.09 and 1.0, respectively, and AC/CE ratios of PM2.5 mass on haze day and non haze day were 1.12 and 1.04, respectively. Also, SOR (Sulfur Oxidation Ratio) of PM10 mass on haze day and non haze day were 0.32 and 0.17, respectively, and SOR of PM2.5 on haze day and non haze day were 0.30 and 0.15, respectively. Lastly, NOR (Nitrogen Oxidation Ratio) of PM10 on haze day and non haze day were 0.17 and 0.08, respectively, and NOR of PM2.5 on haze day and non haze day were 0.13 and 0.06, respectively.
This research investigates the characteristics of meteorological variation and fine particles (PM10 and PM2.5) for case related to the haze occurrence (Asian dust, long range transport, stationary) in Busan. Haze occurrence day was 559 days for 20 years (from 1996 to 2015), haze occurrence frequency was 82 days (14.7%) in March, followed by 67 days (12.0%) in February and 56 days (10.0%) in May. Asian dust occurred most frequently in spring and least in winter, whereas haze occurrence frequency was 31.5% in spring, 29.7% in winter, 21.1% in fall, and 17.7% in summer. PM10 concentration was highest in the occurrence of Asian dust, followed by haze and haze + mist, whereas PM2.5 concentration was highest in the occurrence of haze. These results indicate that understanding the relation between meteorological phenomena and fine particle concentration can provide insight into establishing a strategy to control urban air quality.
현재 미세먼지에 대한 화재가 점점 사람들의 시선을 끌고 있다. 미세먼지는 눈으로 볼 수 없 는 직경이 2.5μm(마이크로미터)인 먼지이며 폐 속 깊숙이 침투 할 수 있어 건강에 많은 피해를 준다. 사람들은 예방법을 알면서도 실행에 옮기지 않는 것은 미세먼지 위험성의 인지도가 낮기 때문이다. 본 논문은 어린이 대상으로 미세먼지의 인위적 원인과 자연적 원인의 생성 요소와 미세먼지 예방요소에 대한 인지도를 향상시키기 위하여 <우마이 탈출>보드게임 개발하여 다수 의 어린에게 테스트를 진행하여 <우마이 탈출>보드게임의 교육적 효과에 대한 연구를 진행하 였다.
신재생에너지원 중 가장 큰 비율을 차지하고 있는 폐기물은 소각, 매립 등으로 폐기되고 있다. 그러나 생활폐기물 에너지화에 대한 연구가 지속적으로 진행됨에 따라, 현재 생활폐기물 처리시설에서는 SRF생산 공정을 도입하고 있는 추세이다. SRF는 평균 3,500 kg/kcal의 발열량을 나타내며, 대체연료로써 주목을 받고 있다. 그러나 SRF는 성형을 위한 추가적인 비용이 필요하기 때문에, 비성형 폐기물의 에너지화 기술에 대한 많은 연구가 진행되고 있다. 폐기물 에너지화 기술 중 가스화는 고형시료를 합성가스로 전환하는 기술로 저급연로를 고 효율화를 기대할 수 있다. 본 연구는 8ton/day 용량 pilot-scale 비성형 고형연료 가스화 공정에서 수행되었으며, 대기오염 방지시설은 사이클론, 열교환기, 탈염/탈질/탈황 장비, 습식 전기집진기, 수분제거장치로 구성되어 있다. 위의 공정에서 최근 문제가 되고 있는 미세먼지를 다단입경분석기를 이용하여 채취하였다. 채취된 시료는 건조 및 무게측정을 통해 대기오염 방지시설 구간별 미세먼지 분포를 살펴보았고, 각 대기오염 방지시설별 제어효율을 도출하였다. 추가적으로 채취된 입도별 미세먼지 시료는 ICP-MS분석을 통해 K, Cr, Mn, Ni, Cu, Zn, As, Cd, Pb에 대한 거동을 살펴보았다.
This study investigates the concentration sudden rise in fine particle according to resuspended dust from paved roads after sudden heavy rain in Busan on August 25, 2015. The localized torrential rainfall in Busan area occurred as tropical airmass flow from the south and polar airmass flow from north merged. Orographic effect of Mt. Geumjeong enforced rainfall and it amounted to maximum 80 ㎜/hr at Dongrae and Geumjeong region in Busan. This heavy rain induced flood and landslide in Busan and the nearby areas. The sudden heavy rain moved soil and gravel from mountainous region, which deposited on paved roads and near roadside. These matters on road suspended by an automobile transit, and increased fine particle concentration of air. In addition outdoor fine particle of high concentration flowed in indoor by shoes, cloths and air circulation.
This study was intended to investigate the effect of sand particle size on the flowability and strength of UHPC. The experimental results indicated that the sand with the particle size of 0.45~0.89 mm led to the best performance in those properties of UHPC.
This study aims to investigate the indoor air quality by analyzing PM10 concentration and metallic elements collected from high school( classroom, science room, assembly room). PM10 concentration of a classroom, a science room, and an assembly hall during the research period was 87.7 ㎍/m3, 75.3㎍/m3, 64.6㎍/m3, respectively. Si of PM10 had highest concentration with 15,427 ng/m3 followed by Na which had 7,205 ng/m3, and the order was Si>Na>Ca>Mg>Fe>K in the classroom. PM10 concentration of a classroom and a science room was each 104.8 ㎍/m3 and 75.3 ㎍/m3 during the semester and PM10 concentration of a classroom and an assembly hall was each 80.9 ㎍/m3 and 64.6 ㎍/m3 during the summer vacation. Based on PM10 and metallic concentration at a classroom on day of week, the concentration of Friday was highest with 112.0 ㎍/m3, and that of Monday was lowest with 65.3 ㎍/m3.
The objectives of this study were to investigate the seasonal characteristics of metallic and ion elements of PM10(Particulate matter with aerodynamic diameter ≤10 ㎛) and the effects of vessels exhaust emission from ships harboring in Busan City. The PM10 samples were collected from January 2010 to October 2010 at Dongsam-dong(coastal area), in Busan City. The particulate matters were analyzed for major water soluble ionic components and metals. The ranges of the PM10 mass concentrations were from 29.8 ㎍/㎥ to 47.0 ㎍/㎥ in Dongsam-dong. The PM10 mass concentrations in Dongsam-dong are very similar to Gwangbok-dong during same sampling periods. These results were understood by the effects of the shipping source emitted from ships anchoraging and running. The concentrations of water-soluble ions and metals in the PM10 had a level of as high as the order of SO4 2- >NO3 - >Cl - and NH4 + >Na + >Ca 2+ >K + >Mg 2+ , respectively. The correlation coefficients(R 2 ) for SO4 2- /PM10 and NH4 + /PM10 of were 0.7446 and 0.7784, respectively, and it showed the high correlation with each other.
This study has been carried out to investigate Electrostatic Precipitator`s(ESP) performance enhancement and removal efficiency of fine particle according to (NH_4)_2SO_4 injection rate.
The following conclusions are derived from the these test results :
1)For plant condition cases, according to the variation of concentration agent [(NH_4)_2SO_4] - 10ppm, 20ppm, 30ppm, 40ppm - ESP`s collection efficiency was increased to 97.74%, 98.95%, 99.04%, 99.47%, when inlet dust loading was 2g/㎥. And when inlet dust loading was 3g/㎥, that was increased to 98.19%, 99.16%, 99.23%, 99.58%.
2)It is seen from this experiments that the increasing 30ppm concentration of (NH_4)_2SO_4 increase the collection efficiency and fine particle emission control.