• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.365-369
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• 2001

EAF's dust has been treated mainly by pyrometallurgical reduction process in rotary kiln furnace to recover valuable metal elements such as Zn and to avoid the disposal of hazardous materials to waste. Recently, hydrometallurgical eletrowinning of zinc from a zinc-amino chloride solution obtained by the leaching of EAF's dust was developed to recover high grade zinc metal from EAF’s dust. But there are some disadvantages in each process such as difficulty of operation condition control and sticking problem in kiln process and low extractability and recovery of zinc owing to insoluble zinc-ferrite in electrowinning process. We propose a new combined process of pyrometallurgical one and hydrometallurgical one to treat EAF's dust efficiently and economically. In this study, ammonium chloride solution leaching of crude zinc oxide recovered from reduction of EAF's dust was carried out to find out the efficiency of zinc extraction from it and the possibility for performance of eletrowinning in the proposed process. Effects of various leaching variables ruck as leaching temperature, concentration of leaching solution and leaching time were investigated. And the leaching results of the crude zinc oxide were compared with those of EAF's dust. The extraction percents of zinc in ammonium chloride solution leaching of the crude zinc oxide recovered from reduction of EAF's dust were above 80% after 60 minutes of leaching under the leaching condition of 4M NH$_4$CI concentration and above leaching temperature of 7$0^{\circ}C$. And the concentrations of zinc in the leached solution were obtained above 50g/$\ell$. The activation energy calculated for zinc extraction in NH$_4$CI leaching was 58.1 KJ/㏖ for EAF's dust and 15.8 KJ/㏖ for the crude zinc oxide recovered from reduction of EAF's dust.

• Asian Journal of Atmospheric Environment
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• 제10권3호
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• pp.162-167
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• 2016

This study was conducted in an industrial city (Bilaspur) representative of subtropical area in central India. In order to assess the metal deposition on plant, concentrations of six target metals (i.e., Fe, Mn, Pb, Cu, Cd, and Cr) in both plant leaf and dust (deposited on its surface) samples were measured from six different sites. Metal concentrations in dust samples were found on the order of Fe>Mn> Cr>Pb>Cu>Cd. In contrast, the concentration of metals in plant leaves were seen on the order of Fe>Mn>Cr>Cd>Cu>Pb. As such, Cd showed significantly high concentration in leaves relative to their corresponding dust samples. A high accumulation potential for Fe and Cd was seen from Butea monosperma, while Mn and Pb were accumulated noticeably in Pongamia pinnata and Butea monosperma. Likewise, Cr and Cu were enriched in Calotropis procera, Alstonia scholaris, and Butea monosperma. The overall results of our study suggest that the foliar uptake pattern should vary considerably by an interactive role between plant and metal types.

• 한국대기환경학회지
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• 제32권1호
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• pp.32-45
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• 2016

The anthropogenic aerosols originated from the pollutant emissions in the eastern part of China and dust emitted in northwestern China in Yellow sand regions are subsequently transported via eastward wind to the Korean peninsula and then these aerosols induce high $PM_{10}$ concentrations in Korean peninsula. In order to estimate air quality considering anthropogenic and dust emissions, Comprehensive Air-quality Model with extension (CAMx) was applied to simulate $PM_{10}$ concentration. The predicted $PM_{10}$ concentrations without/with dust emissions were compared with observations at ambient air quality monitoring sites in China and Korea for 2008. The predicted $PM_{10}$ concentrations with dust emissions could depict the variation of measured $PM_{10}$ especially during Yellow sand events in Korea. The comparisons also showed that predicted $PM_{10}$ concentrations without dust emissions were under-predicted while predictions of $PM_{10}$ concentrations with dust emission were in good agreement with observations. This implied that dust emissions from desert and barren soil in southern Mongolia and northern China minimized the discrepancies in the $PM_{10}$ predictions in East Asia. The effect of dust emission on annual $PM_{10}$ concentrations in Korea Peninsula for year 2008 was $5{\sim}10{\mu}g/m^3$, which were about 20% of observed annual $PM_{10}$ concentrations.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2019년도 추계 학술논문 발표대회
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• pp.172-173
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• 2019

As the damage to fine dust increased, the Republic of Korea designated fine dust as a social disaster. The composition of the fine dust is composed of carbon, sulfate, nitrate, ammonium and minerals. The cause of fine dust is naturally generated by dirt, pollen, etc. In addition, there are artificial causes such as gaseous vehicle exhaust gas emitted from the use of fossil fuel. When fine dust enters the human body through breathing, it causes various respiratory diseases and skin diseases. In IARC, fine dust was designated as a carcinogen group 1. In this research, we tried to adsorb fine dust by physical adsorption using powdered activate carbon. Powdered activate carbon is a powdered activated carbon activated in a carbonized state. Porous material with high specific surface area and low density. Experimental items were tested for density, water absorption, and fine dust concentration according to the PAC addition ratio. Basic experiments were carried out to fabricate the fine dust adsorption matrix.

• Journal of Korean Society for Atmospheric Environment
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• 제17권E4호
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• pp.145-155
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• 2001

Simple mass balance method was developed to estimate the contribution of two major fugitive dust sources in the Port of Incheon to a nearby residential area in this study. Using the relatively small number of TSP data as well as the data on mass fraction of Fe and organic materials in the sampled dust, our simplified method demonstrated its ability to estimate the contribution of each fugitive source to a specific location including the residential area with relatively reasonable accuracy. It is clear from this simple method can be applied to the situation where two major fugitive dust sources are responsible for the high TSP concentration around the source area and there are clear marker chemicals representing the characteristics of the fugitive dust sources.

• Applied Science and Convergence Technology
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• 제26권6호
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• pp.218-222
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• 2017

This study was conducted to remove $NO_x$, which is the main cause of fine dust and air pollution as well as acid rain. $NO_x$ was tested using 3% NO (diluted in He) as a simulated gas. Experiments were sequentially carried out by oxidizing NO to $NO_2$ and absorbing $NO_2$. Especially, we focused on the changes of NO oxidation according to both oxidant ($NaClO_2$) concentration change (1~10 M) and oxidant pH change (pH = 1~5) by adding HCl. In addition, we tried to suggest a method to improve $NO_2$ absorption by conducting $NO_2$ reduction reaction with reducing agent (NaOH) concentration (40~60%). It was found that NO removal efficiency increased as both concentration of oxidant and flow rate of NO gas increased, and NO decreased more effectively as the pH of hydrochloric acid added to the oxidant was lower. The $NO_2$ adsorption was also better with increasing NaOH concentration, but the NO removal efficiency was ~20% lower than that of the selective NO reduction. Indeed, this experimental method is expected to be a new method that can be applied to the capture and removal of fine dust caused by air pollution because it is a method that can easily remove NO gas by a simple device without expensive giant equipment.

• 대기
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• 제20권3호
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• pp.273-286
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• 2010

The northeast part of China(hereafter Manchuria) is one of Asian dust source regions along with Gobi, Inner Mongolia and Loess Plateau. In this study, a geographical survey over the area was carried out to determine its soil characteristics in June 2009. It revealed that some parts of the area, especially near Keerchin desert, consist of alkali clay soil mixed up with sand. Manchuria, where is a vast cornfield, can be a potential source region of Asian dust from fall to following spring after harvesting. The frequency of Asian dust over the region from 1996 to 2009 was examined using 3-hourly GTS SYNOP data and it showed that the occurrence of Asian dust over the region is high in the springtime. It was also revealed that snow cover is the key parameter affecting on the frequency through the analysis of NCEP reanalysis data. To scrutinize the path and structure of Asian dust from Manchuria, the event on 3~4 April 2008 and 25 January 2010 were intensively investigated with regard to features of synoptic weather patterns, satellite imagery, airstream, naked eye-observations, concentrations of PM10, 2.5 and 1.0. For this case, the Asian dust from the area reached to Korea less than a day. However, the duration time of the dust in Korea was short (< 7 hours). The average of hourly PM10 reached up to $340{\mu}g/m^{3}$ at Baengnyeondo during the period. The high PM2.5 and PM1.0 concentrations were also observed at several sites in Korea, indicating that air pollutants could be transported along with the dust.

• Ocean and Polar Research
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• 제44권4호
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• pp.297-310
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• 2022

To understand the chemical composition of aerosols in the Cheju-Korea Straits and their contribution to the ocean by deposition, aerosol samples were collected on board R/V Eardo from November 1997 to May 1999. The average concentrations of Al, NO₃^-, non-sea-salt (nss)-SO₄^2-, and NH₄⁺ in aerosols were 2.19, 5.59, 6.16 and 2.08 ㎍ m^-3, respectively. The Al concentration in the high yellow dust period was about 100 times higher than that in the non-yellow dust period. The concentration ratio of NO₃^-/nss-SO₄^2- ranged between 0.47 and 1.5, indicating that the aerosols in the Cheju-Korea Straits are under the effects of NO_x and SO_x emitted from China, Korea and Japan. The equivalent concentration ratio of [NH₄⁺]/[nss-SO₄^2-+ NO₃^-] with the average of 0.58±0.29 indicates that nss-SO₄^2- and NO₃^- are not neutralized by NH₄⁺. A high activity concentration of ²¹⁰Pb with 1.13-1.23 mBq m^-3 was observed during the high yellow dust period, indicating that ²¹⁰Pb is easily adsorbed in the yellow dust originating from the continent of Asia. The distribution of ⁷Be and NH₄⁺ concentrations showed a strong negative linear correlation during the low yellow dust period, April 1998. The total mineral dust flux in the Cheju-Korea Straits was estimated to be 1.21×10⁶ tons yr^-1, accounting for about 12% of the annual sediment discharge via the Nakdong River. The combined annual deposition of NH₄⁺ and NO₃^- was 0.103 mole N m^-2 yr^-1 was estimated to support 4% of the annual primary productivity in the East China Sea.

• 한국농공학회논문집
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• 제57권6호
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• pp.35-46
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• 2015

Improvement in domestic poultry production has a positive effect on the export competitiveness of the poultry industry. However, overproduction and enlargement of facilities to assure a supply increase a stocking density which make a poor environment in the broiler house. In particular, an intensive rearing environment is vulnerable to dust control that causes respiratory diseases, such as asthma, bronchitis, etc., to farmers and broilers. However, monitoring data and research for environment control are not adequate, and there are no air quality regulations in broiler houses in Korea. In this study, TSP, PM10, inhalable dust and respirable dust concentration were monitored according to season, age of broiler and broiler's activities. Air quality assessment was also performed in accordance with the threshold limit value by Donham et al. (2000). The TSP concentrations were 77.5 %, 219.7 % higher and PM10 concentrations were 121.2 %, 303.8 % higher when change of season and winter respectively than summer. There were significantly different concentrations according to season and age of broiler. Inhalable and respirable dust concentration were also clearly different according to the season and age of broiler. A high dust concentration was observed, specifically exceeding the threshold limit by 119 % in the winter. In the case of the broiler's motion was activity according to worker's access into the broiler house, concentration level was 769.6 % higher than broiler's motion was stable and exceeded the threshold limit. These results suggest that the worker should put on protective equipment to protect there's respiratory health in the broiler house.

• 한국화재소방학회논문지
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• 제12권4호
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• pp.13-19
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• 1998

Hartman식 분진폭발 장치를 이용하여 두 총회 카본블랙 High Black 10과 50L의 업도분포별, 농도별 그리고 동일한 입도분포에서 비표면적과 표면 기능기의 양에 따흔 이뜰 시료의 분진폭발 확 률, 분진폭발 압력 통을 조사함i으로서 카본블랙 분친의 위험성을 평가하고자 하였다\ulcorner 이에 카본블 랙의 비표면적을 측정하고 표면에 존재하는 기놓기룹 정량함으로서 휘발분이나 비표면적이 싱-대 적 으로 넓 몫 Hi - Black 50L의 경 우 f-lilongleftarrowBlack 10에 비 해 상대 적 으로 폭발 획 룹과 폭발 압력 이 크게 나타났으며, 최대폭발압력은 돼- Black 50L의 입도분포 230/270 mesh, 시료농도 0.9 mg/em에서 약 6 6.0 kg/em'으로 나타났다.