• Journal of Korean Society of Water and Wastewater
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• v.20 no.5
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• pp.719-726
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• 2006

Adsorption isotherms and kinetics for taste and odor (T&O) compounds and natural organic matters (NOMs) were performed to evaluate the impacts of activated carbon particle size on coagulation and adsorption. Adsorption capacities for iodine, T&O compounds, and NOM of all the activated carbons under #325 mesh were more excellent than those of virgin activated carbons. Small activated carbon particles were more rapidly adsorbed low molecular weight T&O compounds in the water, while those were slowly adsorbed high molecular weight NOM. When the activated carbon and alum were added simultaneously, the adsorption capacity for organics was better than alum was added alone.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.31 no.5
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• pp.416-424
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• 2007

In adsorption/catalytic process, numerical analysis has been performed to identify the flow characteristics of flue gas in the cyclone and to estimate the residence time of activated carbon using Computational Fluid Dynamics (CFD) technique. To consider flue gas and activated carbon particles simultaneously, Euler-Lagrangian model was employed so that residence time could be obtained from the numerical analysis directly. The numerical analysis has been performed with different three particle sizes and compared each flow characteristics with particle’ size. Fundamental flow patterns of flue gas and activated carbon particles, pressure distribution, residence time of flue gas, and activated carbon particles and distribution of activated carbon have been obtained from the numerical analysis.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.2
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• pp.203-213
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• 2007

Numerical analysis has been performed to understand flow characteristics in the reactor with bag filters in an integrated adsorption/catalytic process which can treat dioxin and $NO_{x}$ together. Computational fluid dynamics technique was employed with Euler-Lagrangian model to consider flue gas and activated carbon particles simultaneously, so that residence time of flue gas and activated carbon particle could be obtained from the numerical analysis directly. The numerical analysis has been performed with different three particle sizes and compared each flow characteristics with particle's size. Fundamental flow patterns of flue gas and activated carbon particles, pressure distribution, residence time of flue gas and activated carbon particles, and distribution of activated carbon have been obtained from the numerical analysis. Flow patterns of flue gas and activated carbon particles in the reactor were very complicated and they moved along very various paths. Therefore, their residence time in the reactor was also various. The results obtained would be effectively used to estimate the removal efficiency in the reactor once the residence time is combined with the reaction equation.

• Journal of Korean Society on Water Environment
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• v.29 no.3
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• pp.337-342
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• 2013

The particle counter compared with the turbidimeter provides good precision and sensitivity and can get the characteristics of particulates effectively. The purpose of this study is to provide the application of particle counter in sand and activated carbon filters. The particle count by size could be more easily sense when the water quality is changed by the influent of high turbidity or algae. We could decide the optimal backwashing cycles and detect the efficiencies of filters by monitoring the total particle count of effluent in sand and activated carbon filters.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.6
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• pp.823-828
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• 2006

For this study, an online particle counter was installed before and after the activated carbon filtration process of D water treatment plant where has advanced water treatment processes, produces average 900,000ton/day of drinking water and supply the produced drinking water to Busan citizens. We collected and analyzed particle count data for about 1 year. We inspected particle breakthrough in three out of sixteen filter processes operated at same conditions, i.e. 5th filter, 6th filter and 7th filter. According to the monitoring results, 6th and 7th filters showed similar results while 5th filter showed different results. When compared seasonal effect, the particle count for dry season was below 10 particles/ml while the particle count for August when monthly average rainfall is over 200mm was much higher than for dry season. In January and August, there was a difference in breakthrough particle size. In January, small particles in 2~3um were mainly detected while in August 10um particles were mainly detected and the size distribution was 40% of total count.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.11a
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• pp.336-337
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• 2005

This study shows the effect of addition of $LiCoO_2$, with different milling time ranging from 0, 30, 200 hours, to the activated carbon electrode. Test cells consisting of activated carbon (100-X%) and $LiCoO_2$ (X%)were made (where X=10, 20, and 40). Test cells with varying concentrations of $LiCoO_2$ which differ in the milling time showed improved specific capacity compare with the cells fabricated using activated carbon alone. The enhanced capacity may be caused due to the addition of $LiCoO_2$ powders at varying concentration. An improved ESR value obtained may be caused by the smaller particle size of $LiCoO_2$. It was concluded that finer the particle size higher will be the efficiency.

• Journal of Electrochemical Science and Technology
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• v.14 no.2
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• pp.184-193
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• 2023

This study investigates the effects of a carbon fiber layer formed on the surface of an etched aluminum current collector on the electrochemical properties of the activated carbon electrodes for an electric double layer capacitor. A particle size analyzer, field-emission SEM, and nitrogen adsorption/desorption isotherm analyzer are employed to analyze the structure of the carbon fiber layer. The electric and electrochemical properties of the activated carbon electrodes using a carbon fiber layer are evaluated using an electrode resistance meter and a charge-discharge tester, respectively. To uniformly coat the surface with carbon fiber, we applied a planetary mill process, adjusted the particle size, and prepared the carbon paste by dispersing in a binder. Subsequently, the carbon paste was coated on the surface of the etched aluminum current collector to form the carbon under layer, after which an activated carbon slurry was coated to form the electrodes. Based on the results, the interface resistance of the EDLC cell made of the current collector with the carbon fiber layer was reduced compared to the cell using the pristine current collector. The interfacial resistance decreased from 0.0143 Ω·cm² to a maximum of 0.0077 Ω·cm². And degradation reactions of the activated carbon electrodes are suppressed in the 3.3 V floating test. We infer that it is because the improved electric network of the carbon fiber layer coated on the current collector surface enhanced the electron collection and interfacial diffusion while protecting the surface of the cathode etched aluminum; thereby suppressing the formation of Al-F compounds.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.4
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• pp.524-533
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• 2003

DBD(Dielectric Barrier Discharge) plasma in air is well established for the production of large quantities of ozone and is more recently being applied to aftertreatment processes for HAPs(Hazardous Air Pollutants). Aim of this work is to determine design and operating parameters of a hybrid air cleaning system. DBD and ESP(Electrostatic Precipitator) are used as nano particle charger and collector, respectively. Pelletized MnO$_2$ catalyst or activated carbon is used fer ozone decomposition or adsorption material. AC voltage of 7～10 KV(rms) and 60 Hz is used as DBD plasma source. DC - 8 KV is applied to the ESP for particle collection. The overall particle collection efficiency for the hybrid system is over 85 % under 0.64 m/s face velocity. Ozone decomposition efficiency with pelletized MnO$_2$ catalyst or activated carbon packed bed is over 90 % when the face velocity is under 0.4 m/s in dry air.

• Journal of the Korean Wood Science and Technology
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• v.50 no.4
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• pp.256-271
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• 2022

Activated carbon (AC) derived from coconut shells (CS-AC) was obtained through pyrolysis at 700℃ and subsequently activated with H₃PO₄. AC was ground in a Wiley mill several times to form powder particles at particle scales of 80, 100, and 200 meshes. The characterization of the AC was studied using scanning electron microscopy (SEM), X-ray diffraction analysis (XRD), Fourier-transform infrared spectroscopy (FT-IR), and surface area analysis (S_BET). The CS-AC-200 mesh resulted in a higher percentage of mesopores and surface area. This particle size had a larger surface area with angular, irregular, and crushed shapes in the SEM view. The smaller particles had smoother surfaces, less wear, and increased curing depth and ratio of the hardness of the resin composite. Based on the characterization results of the AC, it is evident that CS-AC with a 200 mesh particle size has the potential to be used as a filler in biocomposites.

• Journal of Environmental Health Sciences
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• v.19 no.4
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• pp.25-32
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• 1993

Granular activated carbon is commonly used in fixed-bed adsorbers to remove organic chemicals. In this experiment organic chemical solutions were prepared by adding the reagent grade organic chemical to distilled water. Isotherm adsorption tests of volatile organic chemicals were conducted using bottle-point technique and column test. Organic chemicals after passing through the column were extracted with hexane and analyzed with gas chromatography (Hewlett-Packard 5890) to check the adsorption capacity and breakthrough curve. The result were as follows: 1. The BET surface area of coconut activated carbon was 658~1,010 m$^2$/g where as coconut shell carbon was 6.6 m$^2$/g. Coconut activated carbon increased the BET surface area and adsorption capacity in bottle-point isotherm. 2. The adsorption capacity of coconut activated carbon for trichloroethylene (TCE) was reduced in the presence of humic substance. 3. A decrease in particle size of activated carbon resulted in higher adsorption capacity and lower intraparticle diffusion coefficient. It is reflected not only as a decrease in Freudlich adsorption capacity value (K) but also as an increase in Freudlich exponenent value (1/n).