• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.109.2-109.2
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• 2010

세라믹 필터는 여러 종류의 분진제거 시스템에서 연소 배가스 정제를 위한 가장 적절한 소재로 알려져 있다. 현재까지 다양한 형태의 세라믹 필터가 개발되고 있는데, 캔들 타입(candle type), 튜브 타입(tubular type), 평판 타입(parallel flow type) 등이 그 예이다. 통상적으로 세라믹 캔들 필터는 가압유동층복합발전(PFBC, Pressurize Fluidized-Bed Combustion), 석탄가스화복합발전(IGCC, Integrated coal Gasification Combined Cycle), 석탄가스화연료전지복합발전(IGFC, Integrated coal Gasification Fuel cell Combined cycle)에서 고온 배가스 정제용으로 사용되고 있다. 일반적으로 IGCC나 CTL 합성가스 정제시스템의 경우에는 높은 고압(약 25기압)과 미세분진이 함유되어 있는 분위기에서 운전된다. 그러므로 이때 사용되는 초청정용 세라믹 집진필터는 고온, 고압 및 부식 환경에서 50 MPa 이상을 갖는 높은 강도와 내식성을 갖도록 개발되어야 하기 때문에 SiC(Silicon Carbide)가 가장 적절한 캔들 필터 소재로 적용되고 있다. 이에 따라 집진용 SiC 세라믹 캔들 필터를 개발하기 위해서는 고온에서 내산화성이 우수하고, 부피팽창에 의한 균열이 발생하지 않는 무기결합재의 선정 및 이를 통한 소재의 특성 최적화가 가장 중요한 부분이라 할 수 있다. 본 연구에서는 IGCC나 CTL 공정에 적용하기 위한 SiC 캔들 필터 소재 개발을 위해 래밍성형 공정으로 1m급의 탄화규소 캔들 필터 시작품을 제작하여 SiC 출발입자 크기와 무기계 결합재인 스트론튬 카보네이트의 첨가량 변화에 따른 필터 소재의 특성 평가를 수행하였다.

• Particle and aerosol research
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• v.13 no.1
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• pp.11-16
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• 2017

Indoor air quality is of increasing concern because it is closely related human health. An air handling unit (AHU) can be used to control the indoor air quality related to particulate matters and $CO_2$ as well as air conditioning such as temperature and humidity of indoor air. An electrostatic precipitator has a high collection efficiency and low pressure drop, however, ozone can possibly generate from its chargers, which is one of drawbacks to apply it for indoor air control. Here we compared four charging electrodes such as a $50{\mu}m$ tungsten wire, a $100{\mu}m$ tungsten wire, a $16{\mu}m$-thickness Al foil and a carbon fabric comprised of $5-10{\mu}m$ fibers. The carbon fabric electrode showed a superior particle collection efficiency and a lower ozone generation at a given power consumption compared to tungsten wires of 50, $100{\mu}m$ and an Al foil electrode. This low ozone generating, micro-sized electrode can be applied to the electrostatic precipitator in AHU for indoor air control.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.150-150
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• 2016

Mankind is enjoying a great convenience of their life by the rapid growth of secondary industry since the Industrial Revolution and it is possible due to the invention of huge power such as engine. The automobile which plays the important role of industrial development and human movement is powered by the Engine Module, and especially Diesel engine is widely used because of mechanical durability and energy efficiency. The main work mechanism of the Diesel engine is composed of inhalation of the organic material (coal, oil, etc.), combustion, explosion and exhaust Cycle process then the carbon compound emissions during the last exhaust process are essential which is known as the major causes of air pollution issues in recent years. In particular, COx, called carbon oxide compound which is composed of a very small size of the particles from several ten to hundred nano meter and they exist as a suspension in the atmosphere. These Diesel particles can be accumulated at the respiratory organs and cause many serious diseases. In order to compensate for the weak point of such a Diesel Engine, the DPF(Diesel Particulate Filter) post-cleaning equipment has been used and it mainly consists of ceramic materials(SiC, Cordierite etc) because of the necessity for the engine system durability on the exposure of high temperature, high pressure and chemical harsh environmental. Ceramic Material filter, but it remains a lot of problems yet, such as limitations of collecting very small particles below micro size, high cost due to difficulties of manufacturing process and low fuel consumption efficiency due to back pressure increase by the small pore structure. This study is to test the possibility of new structure by direct infiltration of SiC Whisker on Carbon felt as the next generation filter and this new filter is expected to improve the above various problems of the Ceramic DPF currently in use and reduction of the cost simultaneously. In this experiment, non-catalytic VS CVD (Vapor-Solid Chemical Vaporized Deposition) system was adopted to keep high mechanical properties of SiC and MTS (Methyl-Trichloro-Silane) gas used as source and H2 gas used as dilute gas. From this, the suitable whisker growth for high performance filter was observed depending on each deposition conditions change (input gas ratio, temperature, mass flow rate etc.).

• Journal of Korean Society on Water Environment
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• v.21 no.6
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• pp.669-675
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• 2005

Biological nitrate removal from groundwater was investigated in the biofilters packed with both gravel/sand and plastic media. Removal of particles and turbidity were also investigated in the 2-stage biofilter system consisted of biofilter and subsequent sand filter. In the single biofilter packed with gravel and sand, nitrate removal efficiency was dropped with the increase of filtration velocity and furthermore, nitrite concentration increased up to 3.2 mg-N/L at 60 m/day. Denitrification rate at the bottom layer below 25 cm was faster 8 times than upper layer in the up-flow biofilter. Nitrite build-up, due to the deficiency of organic electron donors, occurred at the upper layer of bed. Besides DO concentration and organic carbon, contact time in media was the main factor for nitrate removal in a biofilter. The most of the effluent particles from biofilter was in the range from 0.5 to $2.0{\mu}m$, which resulted in high turbidity of 1.8 NTU. However, sand filter followed by biofilter efficiently performed the removal of particles and turbidity, which could reduce the turbidity of final filtrate below 0.5 NTU. Influent nitrate was removed completely in the 2-stage biofilter and no nitrite was detected.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.3
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• pp.153-159
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• 2007

Nano-Particles are influenced on the environmental protection and human health. The relationships between transient vehicle operation and nano-particle emissions are not well-known, especially for diesel passenger vehicles with DPF. In this study, a diesel passenger vehicle was measured on condition of DPF regeneration and no regeneration on a chassis dynamometer test bench. The particulate matter (PM) emission from this vehicle was measured by its number, size and mass measurement. The mass of the total PM was evaluated with the standard gravimetric measurement method while the total number and size concentrations were measured on a NEDC driving cycle using Condensation Particle Counter (CPC) and EEPS. Total number concentration by CPC was $1.5{\times}10^{1l}N/km$, which was 20% of result by EEPS. This means about 80% of total particle emission is consist of volatile and small-sized particles(<22nm). During regeneration, particle emission was $6.2{\times}10^{12}N/km$, was emitted 400 times compared with the emission before regeneration. As for the particle size of $22{\sim}100nm$ was emitted mainly, showing peak value of near 40nm in size. This means regeneration decreased the mean size of particles. Regarding regeneration, PM showed no change while the particle number showed about 6 times difference between before and after regeneration. It seems that the regeneration influences on particle number emissions are related to DPF-fill state and filtration efficiency.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.4
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• pp.327-335
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• 2002

Effects of available food on growth of commercially cultured Pacific oysters, Crassostrea gigas in Goseong Bay on the south coast were studied using a numerical model. levels of total protein, carbohydrate and lipid in particulate organic matter in the water column as well as chlorophyll a concentration were determined for estimating total available food for oyster growth. Environmental parameters including water temperature, salinity and total suspended solid were also monitored for the model. Oyster growth was also monitored by means of measuring shell length and tissue wet weight increase on a monthly basis. Simulation results from the numerical model indicated that chlorophyll a is not a good representative of available food for the oysters in Goseong Bay. In contrast, available food in the water column measured by filtration of the organic particles and analyzed in terms of total lipids, carbohydrates and protein was well matched with simulated oyster growth in the Bay which is similar to observed growth. The model also suggested that oysters have relatively low retention efficiency of $50\%$ or less. This result indicates that oysters in the bay utilize only a part of food particle available in the water column, as reported in other studies.

• Journal of Environmental Impact Assessment
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• v.32 no.3
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• pp.166-175
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• 2023

This study aims to identify the cause of the red-water occurrence (the phenomenon of water being red) that occurs at some points and sections of rivers in Yongin City. As a result of conducting a preliminary investigation, total three sites were selected as the investigation point as it was found that the red-water occurrence continued. As a result of the investigation, it is judged that the cause of the red-water in Yongin-city river is due to the soil color and iron content of the region. JPS, SBS, and JJS sites all showed that the color of soil is mainly consist of reddish brown and red-yellow. The average Fe concentration was 13.75 mg/L, 10.85 mg/L, and 1.31 mg/L, for each sites, and considering that the Fe concentration in general river water was less than 0.5 mg/L, it was confirmed that the concentration was quite high. At the JPS and JJS points, the red-water occurrence occurred mainly in stagnant places, which is believed to be strengthened by the reaction of organic and microorganisms. In the case of SBS, the wateris red, but as a result of observing the actual color, it is judged that the iron component deposited in the pipe causes an optical illusion with a deep red color. In addition, it is believed that the iron concentration can be reduced to the general river water concentration range by removing the particulate iron component through a decrease of more than 95% as a result of filtering with glass fiber filter with particulate iron. As a result of this study, it is necessary to manage the river to maintain the flow, and it is believed that the occurrence of red-water at the survey point can be alleviated through uptake action through planting and agglomeration precipitation and agglomeration filtration methods for particulate iron treatment.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.3
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• pp.332-340
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• 2007

Storm runoff from road contains significant loads of particulate and dissolved solids, organic constituents and metal elements. Micro particle is important when considering pollution mitigation because pollutant metal and organics have similar behavior with particles. The objective of this research is to evaluate the hydrodynamic filter separator performance for road storm runoff treatment. A various types of media such as perlite, granular activated carbon, zeolite were used for column test packing media and filter separator, and to determine the removal efficiency with various surface loading rate. As the results of column test, the highest SS removal efficiency was using mixed media(granular activated carbon, zeolite and perlite), and granular activated carbon mixed with zeolite has higher heavy metal removal efficiency than perlite. In laboratory scale hydrodynamic filter separator study, the operation ranges of surface loading rates were from 192 to 1,469 $m^3/m^2/day$. The estimated overall removal efficiencies of hydrodynamic filter separator for typical storm runoff were SS 48.1%, BOD 31.9%, COD 32.6%, TN 15.5%, and TP 17.3%, respectively. For the case of heavy metals, overall removal efficiencies were Fe 26.0%, Cu 19.4%, Cr 25.7, Zn 16.6%, and Pb 15.0%, respectively. The most appropriate medium for hydrodynamic filter separator was perlite mixed with granular activated carbon to treatment of road storm runoff.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.6
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• pp.613-619
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• 2006

The objectives of this research are to evaluate the effect of membrane materials, particulate matter and membrane pore size on permeate flux. It was shown that the removal efficiency of high MW organic matter more than 10 kDa was lower than that of low MW organic matter for $MIEX^{(R)}$ process. For the change of permeate flux by the pretreatment process, $MIEX^{(R)}+UF$ process showed high removal efficiency of organic matter as compared with coagulation+UF processes, but high reduction rate of permeate flux was presented through the reduction of removal efficiency of high MW organic matter. The pretreatment of the raw water significantly reduced the fouling of the hydrophilic membrane, but did not decrease the flux reduction of the hydrophobic membrane. Flux decline on MF process increased due to the pore clogging, while the permeate flux decline of UF process decreased due to the formation of cake layer. It was shown that particle matter was not effect on MIEX+membrane process. But, for coagulation+membrane process, particle matter was important factor on permeate flux.

• Journal of Wetlands Research
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• v.20 no.2
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• pp.145-154
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• 2018

In this study, three pilot-scale wetland systems were built for treating stormwater runoff from asphalt road. Each of the system consists of a settling tank and a vertical flow wetland packed with 25%, 50%, and 75% woodchip as treatment media. According to the analysis of the distributions of particle size, it was found that solids ranging in size $0.52-30{\mu}m$ were predominant in the stormwater runoff. After 24-hours settling, those coarser than $20{\mu}m$ were significantly detained. Further retention, especially for the finer-sized fraction, occurred in the wetland through internal recirculation during the dry day periods. As a primary media of the wetland, woodchip showed a high filtration and attachment capacity for the particulates in pre-settled stormwater, whereas overall amount of solids in the wetland effluent increased due to the detachment of woody elements from the media. This was observed mainly during the initial 75 days of operation, and the size and detachment rate were found to be strongly related with the woodchip packing ratio. The mechanism involving woody particle detachment was modeled as a first-order form. In addition, water quality factors and operational parameters affecting the detachment were analyzed and discussed.