• Journal of Korean Society of Water and Wastewater
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• v.11 no.1
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• pp.88-98
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• 1997

To obtain design and operating parameters for advanced water facilities, pilot test consisted of ozonation and GAC filtration was conducted at midstream of Nakdong River. Even though the concentrations were very low, 62 chemicals were detected above $0.005{\mu}g/L$ in raw water. In the preozonation, natural organic matters which could produce THMs and organics such as phenols and amines were effectively removed. The performance of TOC removal of GAC filtration with ozonation was better than GAC filtration alone and adsorption capacity of GAC adsorbers were ranged 3~6mg-TOC/g-carbon. And also the life of GAC adsorber for removing TOC was predicted more than 1 years if ozonation is introduced. This indicates that biological degradation of organics happened in GAC filters. Most organics detected at ppt level were removed below detection limit by GAC filtration with ozonation. These results show that ozonation and GAC filtration are the reliable and safe process for organic contaminants and chlorinated byproducts control at Nakdong River.

• Journal of Korean Society of Water and Wastewater
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• v.24 no.2
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• pp.237-246
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• 2010

This study was carried out to compare the performances of hydrophobic and hydrophilic membranes in the filtration of the pretreatment waters using coagulants such as PAC and PAHCs, and to investigate the influence of NOM characteristics on the fouling of membranes. As a result, the hydrophobic fraction was more effectively removed by PAHCs, however the transphilic and hydrophilic fraction were more effectively removed by PAC on NOM removal. Raw water showed the highest response in the range of humic substances, and pre-coagulated waters with PAC and PAHCs followed. It was also observed that the fouling effect for a hydrophobic membrane was greater than that of a hydrophilic membrane with a similar pore size, due to fouling caused by adsorption. Foulants causing significant flux decline were alcoholic compounds (polysaccharide-like) and humic substances including aromatic groups. Especially, it appeared that alcoholic compounds such as polysaccharide-like substances which mostly remained after coagulation pretreatment had most influence on fouling. It was found that fouling were influenced by each fraction NOM components depending on coagulants used. And PAHCs was more efficient for membrane fouling than PAC.

• Journal of Hydrogen and New Energy
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• v.20 no.4
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• pp.352-359
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• 2009

KEPRI is developing a Korean type coal-gasification system and the scale is 20 ton/day. Prior to this pilot plant, a 1 ton/day class gasification system will be used for pre-testing of several coal types. This paper introduces the configuration and design conditions of this 1 ton/day class system, presenting the gas/coal ratio, oxygen/coal ratio, cold gas efficiency, CFD analysis of gasifier, and others. The existing combustion furnace for residual oil was retrofitted as a coal gasifier and a vertical and down-flow type burner was manufactured. Ash removal is carried out through a water quencher and a scrubber following the quencher, and the sulfur is removed by adsorption in the activated carbon tower. The gas produced from the gasifier is burned at the flare stack. In this paper, the results of design conditions and initial operation conditions of I ton/day gasification system are compared together.

• Journal of Environmental Science International
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• v.15 no.9
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• pp.855-864
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• 2006

This study introduces a method to eliminate formaldehyde and benzene, toluene from indoor air by means of a photocatalytic oxidation reaction. In the method introduced, for the good performance of the reaction, the effect and interactions of the $TiO_2$ catalyst and ultraviolet in photocatalytic degradation on the reaction area, dosages of catalysts, humidity and light should be precisely examined and controled. Experiments has been carried out under various intensities of UV light and initial concentrations of formaldehyde, benzene and toluene to investigate the removal efficiency of the pollutants. Reactors in the experiments consist of an annular type Pyrex glass flow reactor and an 11W germicidal lamp. Results of the experiments showed reduction of formaldehyde, benzene and toluene in ultraviolet $/TiO_2/$ activated carbon processes (photooxidation-photocatalytic oxidation-adsorption processes), from 98% to 90%, from 98% to 93% and from 99% to 97% respectively. Form the results we can get a conclusion that a ultraviolet/Tio2/activated carbon system used in the method introduced is a powerful one for th treatment of formaldehyde, benzene and toluene of indoor spaces.

• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.2
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• pp.77-85
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• 2013

The aim of this study is to investigate strength and water purification characteristics of effective microorganism-applied volcanic ash block using flexural strength test and water quality analysis. The specimens were prepared with volcanic ash from Mt. Baekdusan and Mt. Hallasan, and cement as the ratios of 3.5:1, 4.0:1, 4.5:1, 5.0:1 with and without metakaolin. Flexural strength degraded with increasing of the amount of volcanic ash, and increased with addition of metakaolin as a binder. Based on these results, the optimal ratio for fabricating volcanic ash-cement mixture block is determined as 3.5:1 with metakaolin. Furthermore, from water quality analysis on contaminated water, removal ability of effective microorganism-applied volcanic ash-cement mixture block and caged volcanic ash block against T-N, T-P and SS was highly evaluated because of adsorption due to the large specific surface area of volcanic ash. Hence, volcanic ash-cement mixture block and caged volcanic ash block possibly contribute to water purification.

• Membrane and Water Treatment
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• v.8 no.5
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• pp.437-448
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• 2017

A high quality Na-X zeolite membrane was synthesized on a seeded ${\alpha}-alumina$ disc by the secondary growth method. Structural characterization was done by X-ray spectroscopy, FT-IR spectroscopy, SEM and AFM imaging. The performance evaluation of the membrane was firstly tested in separation of glucose/water solutions by pervaporation process. There was obtained a separation factor $182.7{\pm}8.8$, while the flux through the membrane was $3.6{\pm}0.3kg\;m^{-2}\;h^{-1}$. The zeolite membrane was then used for desalination of aqueous solutions consisting of $Na^+$, $Ca^{2+}$, $Cs^+$ and $Sr^{2+}$ because of the importance of these ions in water and wastewater treatments. The effects of some parameters such as temperature and solution concentration on the desalination process were studied for investigating of diffusion/adsorption mechanism in membrane separation. Finally, high water fluxes ranged from 2 up to $9kg\;m^{-2}\;h^{-1}$ were obtained and the rejection factors were resulted more than 95% for $Na^+$ and $Ca^{2+}$ and near to 99% for $Cs^+$ and $Sr^{2+}$. Based on the results, fluxes were significantly improved due to convenient passage of water molecules from large pores of NaX, while the fouling was declining dramatically. Based on the results, NaX zeolite can efficiently use for the removal of different cations from wastewaters.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.13 no.3_4
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• pp.89-95
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• 2007

Functional packaging paper containing botanical antimicrobial agent (BAAG) and inorganic zeolite was developed for antimicrobial activity and adsorption of ethylene gas of the paper. The physical properties of the packaging paper showed different characteristics with addition of BAAG and functional fillers: both tensile strength and burst strength were decreased, but both stiffness and tear strength were slightly increased. Zeolite also contributed to fast removal of ethylene gas known as aging hormone of fruits and vegetables. Alkyl ketene dimer (AKD) was greatly effective to endow the packaging paper with water repellency property.

• International conference on construction engineering and project management
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• 2024.07a
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• pp.238-241
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• 2024

With the development of living standard, people spend more time indoors, and the diversified home decoration will lead to indoor hazardous gas emission. Among them, formaldehyde (HCHO) is one of the most important sources of indoor air pollution, which is commonly found in building materials as a human carcinogen. To address this issue, we developed highly efficient multifunctional green building coatings (GBC) by TiO₂, enhancement silica fume (ESF) and spent fluid catalytic cracking catalysts (sFCCC). Among these prepared GBC, the GBC-0.8 exhibited HCHO removal efficiency of 85.0 % under visible light at ambient temperature, which was much higher than that of commercial coatings (30.8%). In addition, moisture adsorption-desorption carrier tests were executed by different humidity. The humidity control capacity of GBC-0.8 could reach 293.8 g/m² and demonstrate superior stability after 3 cycles. Compared with pristine TiO₂, the addition of ESF and sFCCC showed higher specific surface area and pore size distribution, which was beneficial to improve humidity control and photocatalytic degradation performance. This study provides a promising green method for designing multifunctional green building materials coatings to recycle waste into high-value products and remove HCHO at room temperature

• Proceedings of KOSOMES biannual meeting
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• 2004.05b
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• pp.81-84
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• 2004

Control of Sediment is very important in prawn farm due to the eruption of toxic material such as W1ionized H2S, NH3 and NO2-. In this study, column test study, column with filter media such as activated carbon, zeolite, oyster shell and iron chloride to evaluate the reduction of toxicity from sediment ammonia-N(NH3) was effectively removed by Zeolite and oyster shell. It was indicated that ammonium ion(NH4+) was removed by ion exchange of zeolite. And the ammonia in the column of oyster shell was existed as the form of NH4+, which is not toxic for prawn because oyster shell was stably kept around pH 8. Therefore, some of ammonia(NH3) was reduced by oyster shell. Hydrogen sulfide and COD were effectively removed by adsorption of activated carbon and a partial removal of hydrogen sulfide was accomplished by Oyster shell. Phosphorous was removed by activated carbon, oyster shell and iron chloride. In prawn farm, the concentration of ammonia was increased with increase of pH by algae photosynthesis in the column of activated carbon, zeolite and iron chloride, but it was revealed that pH was stably kept in the column of oyster shell.

• Carbon letters
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• v.10 no.3
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• pp.217-220
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• 2009

In this study, porous electrospun carbon fibers were prepared by electrospinning with PAN and $MgCl_2$, as a MgO precursor. MgO was selected as a substrate because of its chemical and thermal stability, no reaction with carbon, and ease of removal after carbonization by dissolving out in acidic solutions. $MgCl_2$ was mixed with polyacrylonitrile (PAN) solution as a precursor of MgO with various weight ratios of $MgCl_2$/PAN. The average diameter of porous electrospun carbon fibers increased from 1.3 to 3 ${\mu}m$, as the $MgCl_2$ to PAN weight ratio increased. During the stabilization step, $MgCl_2$ was hydrolyzed to MgOHCl by heat treatment. At elevated temperature of 823 K for carbonization step, MgOHCl was decomposed to MgO. Specific surface area and pore structure of prepared electrospun carbon fibers were decided by weight ratio of $MgCl_2$/PAN. The amount of hydrogen storage increased with increase of specific surface area and micropore volume of prepared electrospun carbon fibers.