• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.4 no.4
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• pp.221-225
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• 2000

Pseudomonas sp. EL-G527 was grown to produce a biosurfactant on 2% n-hexadecane as the energy and carbon source. This biosurfactant significantly reduced the surface tension of water from 72 to 28 dyne/cm at a critical micelle concentration(CMC) of 140 mg/l at pH 2.0. As the pH value decreased, the reduction in the surface tension due to the biosurfactant increased. The surface activity of the biosurfactant was unaffected when the NaCl concentration was increased to 5% and the calcium ion concentration increased to 100 mM, plus it remained stable at 10$0^{\circ}C$ for 180 min.

• Korean Journal of Materials Research
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• v.27 no.3
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• pp.127-131
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• 2017

Isosteric heat of hydrogen adsorption is one of the most important parameters required to describe solid-state hydrogen storage systems. Typically, it is calculated from adsorption isotherms measured at 77K (liquid N2) and 87K (liquid Ar). This simple calculation, however, results in a high degree of uncertainty due to the small temperature range. Therefore, the original Sievert type setup is upgraded using a heating and cooling device to regulate the wide sample temperature. This upgraded setup allows a wide temperature range for isotherms (77K ~ 117K) providing a minimized uncertainty (error) of measurement for adsorption enthalpy calculation and yielding reliable results. To this end, we measure the isosteric heats of hydrogen adsorption of two prototypical samples: activated carbon and metal-organic frameworks (e.g. MIL-53), and compared the small temperature range (77~87K) to the wide one (77K ~ 117K).

• Journal of Environmental Science International
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• v.11 no.4
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• pp.355-360
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• 2002

This study was to analyze the right of wrong of gray-water treatment by applying BPBE electrode cell to the effluence water in the terminal disposal plant of sewage. The results were as follows : The best result was obtained with applied voltage 40V and detention time 6 minutes for the BPBE electrode cell which has the graphite-plate in main electro-de, packing coconut activated carbon. The elimination rate of COD of Al-plate was higher than that of graphite-plate in main electrode. The result of electrolysis for 3 hour in parallel circuit showed the using possibility of gray-water according to each elimination rate : COD 59%, T-N 69 %, T-P 69%. The BPBE electrode cell with the Al-plate in main electrode made the best effect for the elimination of algae in lake water and algae were not occurred in electrolytic water.

• Proceedings of the KAIS Fall Conference
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• 2001.05a
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• pp.84-86
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• 2001

본 논문에서는 고성능 활성탄의 악취 및 유해가스 흡착효율과 멜트브로운(M/B)부직포의 여과성능에 의한 복합적인 고기능 방진특성을 갖는 활성탄 부착 M/B 국산화 여과재를 제조개발하였다. 고성능 활성탄은 고순도의 일반활성탄에 금속염, 유기물 등을 담지시켜 활성화시킨 활성탄이고, M/B여과재의 웹(web)제조조건은 M/B 방사기에서 방사온도 250℃, 방사속도 150m/sec, 고온공기온도 250℃ 그리고 DCD(die to collector distance) 20cm가 적합함을 알 수 있었다. 또한 M/B 여과재에 활성탄 부착은 열롤러시스템에 의한 열적결합방법을 이용하여 균일한 분포의 점접착결합구조를 갖도록 하였고, 개발된 복합기능 여과재가 방진마스크용 여과재로의 이용이 가능하다는 것을 분진포집효율, 투과율, 흡기저항 등 여과재 성능기준실험 결과를 통해 확인하였다.

• Bulletin of the Korean Chemical Society
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• v.19 no.6
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• pp.617-618
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• 1998

A simple and reproducible pretreatment method was developed for the determination of dioxins in milk sample. Liquid-liquid extraction (LLE) was used for the initial extraction of the analyte from milk. For the elimination of interferences coextracted from milk, acid treatment followed by multilayer silica gel, and then alumina column clean-up were performed. The clean extract could be obtained without carbon column or high performance liquid chromatographic (HPLC) clean-up procedure. Polychlorinated biphenyles (PCBs) and dioxins were separated on neutral alumina activated at 180 ℃ for 12 hours. The final extract was analyzed by HPLC and high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS). The recovery of dioxins spiked in milk at 75-300 ppt level was 83.3-98.9% and their relative standard deviation was 4.1-14%.

• Applied Chemistry for Engineering
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• v.19 no.2
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• pp.185-190
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• 2008

In order to increase the surface area of electrodes for electrosorption, porous carbon electrodes were fabricated by a wet phase inversion method. A carbon slurry consisting of a mixture of activated carbon powder (ACP), polyvinylidene fluoride (PVdF), and N-methyl-2-pyrrolidone (NMP) as a solvent was cast directly on a graphite sheet. The cast film was then immersed in pure water for phase inversion. The physical and electrochemical properties of the electrodes were investigated using scanning electron microscopy (SEM), porosimetry, and cyclic voltammetry. The SEM images verified that the pores of various sizes were formed uniformly on the electrode surface. The average pore sizes determined for the electrodes fabricated with various NMP contents ranged from 64.2 to 82.4 nm and the size increased as the NMP content increased. All of the voltammograms showed a typical behavior of charging and discharging characteristic at the electric double layer. The electrical capacitance ranged from 3.88 to $5.87F/cm^2$ depending on the NMP contents, and the electrical capacitance increased as the solvent content decreased. The experimental results showed that the solvent content is an important variable controlling pore size and ultimately the capacitance of the electrode.

• Journal of the Korea Organic Resources Recycling Association
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• v.13 no.4
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• pp.136-147
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• 2005

Leachate from landfill sites contains high organics, chloride and ammonium nitrogen in concentration which might be potentially major pollutants to surface and groundwater environment. Most of landfill leachate treatment plants in Korea consist of biological processes to remove BOD and nitrogen. However, the efficiencies of refractory organics removal, nitrification and denitrification have not met frequently the national effluent regulation of wastewater treatment facility, especially in winter season. Simultaneous removal of organics and nitrogen from leachate is strongly necessitated to meet the national regulation on effluents from leachate treatment facilities. The intermittently aerated biological activated carbon fluidized bed(IABACFB) process was applied to treat real landfill leachates containing refractory organics and high concentration of ammonium nitrogen. The IABACFB reactor consisted of a single bed in which BAC fluidizing and an aerating column. The fluidized bed is intermittently aerated through the blower located at the aerating column. Experiments were performed to evaluate the applicability of Intermittently Aerated BACFB for simultaneous removal of refractory organic carbon and ammonium nitrogen of leachate. Organics and ammonia nitrogen($NH{_4}{^+}-N$)are oxidized during the aerobic stage, and nitrite-nitrate nitrogen($NO{_x}{^-}-N$) are removed to nitrogen gas through denitrification reaction during anoxic state. The IABACFB reactor condition reached a steady state within 40 days since the reactors had been operated. The blowing mode of 60 min.-On/60 min.-OFF is more compatible to remove TOC and ($NH{_4}{^+}-N$) operated. The blowing mode of 60 min.-On/60 min.-OFF is more compatible to remove TOC and ($NH{_4}{^+}-N$) simultaneously than the mode of 30 min.-On/90 min.-OFF. The average removal efficiencies of TOC, the refractory organic carbon, and the average efficiencies of nitrification and denitrification were 90%, 75%, 80%, 95%, respectively.

• Journal of Environmental Health Sciences
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• v.23 no.1
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• pp.95-104
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• 1997

The objectives of this study are to investigate the effect of media on the removal efficiency of nitrate-nitrogen and the biofilm thickness in the fluidized bed biofilm reactor(FBBR) used for the high rate denitrification of nitric acid wastewater. Granular activated carbon(GAC) of 1.274 mm diameter and sand of 0.455 mm diameter were used as the media in the FBBR of 0.05 m diameter and 1.5 m height. As the nitrate-nitrogen concentration of the influent was increased stepwise from 600 to 4800 mg/l, the nitrate- and nitrite-nitrogen concentration of the effluent, biofilm thickness and biofilm dry density were measured to study the effects of media on the denitrification efficiency. The biofilm thickness increased with the substrate loading rate, and the biofilm dry density decreased with the increase of the biofilm thickness. At the influent nitrate-nitrogen concentration of 2400 mg/l, the removal efficiency in the FBBR with GAC was 88%, while that in the FBBR with sand was 99.6%. The biofilm in the FBBR with GAC was so thick, 754.9 $\mu$m, as to increase the mass transfer resistance, compared to that, 143.7 $\mu$m, in the FBBR with sand. The maximum specific denitrification rate in the FBBR with GAC was 15.0 kg-N/m$^3\cdot$ day, while that in the FBBR with sand was 18.0 kg-N/m$^3\cdot$ day. The biomass concentration in the FBBR with sand exhibited the high value 37 kg/m$^3$.

• Journal of environmental and Sanitary engineering
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• v.22 no.1 s.63
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• pp.17-27
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• 2007

This study was conducted the adsorption experiment way of organic wastewater (BOD, COD, TOC, T-N, T-P) by changing the carbonization temperature and the size of adsorbent to examine the adsorption capacity of Korean traditional charcoal which has similar characteristics to activated carbon of organic pollutants. Also, it was performed the basic experiment for pH and inorganic materials. As a result of observing Korean traditional charcoal with has the greatest inorganic contents which are the important factor of chemical adsorption. As the carbonization temperature was better high temperature charcoal than law temperature charcoal to adsorption capacity of pollutant and as the particle was minute (D size : $3.35mm{\sim}2.0mm$), it was most effective. The result of adsorption experiment of organic wastewater show that the elimination ratio of pollutants by bamboo high temperature charcoal was found as BOD(82.1%), COD(91.7%), TOC(52.4%), T-N(66.6%), T-P(83.2%) and it has most excellent adsorption capacity of organic pollutants.

• Journal of Life Science
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• v.15 no.5 s.72
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• pp.696-702
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• 2005

Ozonation is a disinfection technique of harmful mi-crobes commonly used in the treatment of drinking water. And Biological Activated Carbon (BAC) treatment also provides numerous benefits for drinking water utilities, including removal of micro- pollutants, improved treatment processes. The multiful-stage ozonation and BAC play roles as effective methods for removing several materials in raw water. Water quality variation in Nak dong river and the removal efficiency of viruses by ozonation-BAC process were investigated on pilot scale. During the period of survey, most of water quality parameters including $NH_{4}^{+}-N$ were highly improved after passing through the BAC. The removal efficiency of poliovirus type III in water treatment process using pilot-plant,$ 99.6\% $ of viruses were removed by pre-ozonation, sedimentation and sand filteration process, $ 100\% $ were removed after in BAC filteration step. In the removal survey of viruses by ozonation, ap-proximately $ 61.1\% $ or polioviruses were inactivated by ozone of 0.4 mg/l within 5 min. and $ 100\% $ were inactivated by ozone of 0.8 mg/l over 10 min.