• Journal of Electrochemical Science and Technology
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• 제12권1호
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• pp.126-136
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• 2021

The electrochemical performance of all-solid-state cells (ASSCs) based on sulfide electrolytes is critically affected by the undesirable interfacial reactions between oxide cathodes and sulfide electrolytes because of the high reactivity of sulfide electrolytes. Based on the concept that the interfacial reactions are highly dependent on the type of sulfide electrolyte, the electrochemical properties of the ASSCs prepared using three types of sulfide electrolytes were observed and compared. The Li2MoO4-LiI coating layer was also introduced to suppress the interfacial reactions. The cells using argyrodite electrolyte exhibited a higher capacity and Coulombic efficiency than the cells using 75Li2S-22P2S5-3Li2SO4 and Li7P3S11 electrolytes, indicating that the argyrodite electrolyte is less reactive with cathodes than other electrolytes. Moreover, the introduction of Li2MoO4-LiI coating on the cathode surface significantly enhanced the electrochemical performance of ASSCs because of the protection of coating layer. Pulverization of argyrodite electrolyte is also effective in increasing the capacity of cells because the smaller size of electrolyte particles improved the contact stability between the cathode and the sulfide electrolyte. The cyclic performance of cells was also enhanced by pulverized electrolyte, which is also associated with improved contact stability at the cathode/electrolyte. These results show that the introduction of Li2MoO4-LiI coating and the use of pulverized sulfide electrolyte can exhibit a synergic effect of suppressed interfacial reaction by the coating layer and improved contact stability owing to the small particle size of electrolyte.

• 청정기술
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• 제25권3호
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• pp.189-197
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• 2019

본 연구에서는 대표 악취물질로 분류되는 황화수소(hydrogen sulfide, $H_2S$)를 처리하기 위해 3원계의 금속이온 물질이 담지된 활성탄의 제조조건 최적화에 대한 연구를 수행하였다. $H_2S$ 흡착성능 증진을 위한 금속이온 물질로는 $H_2S$ 흡착성능 증진 물질인 KI를 기반으로 Li 및 Fe 또는 3원계(K, Li, Fe)로 조합 시 성능 증진을 확인하였으며, 이는 XRD 분석을 통해 각 활성 물질의 $H_2S$와의 반응 또한 결합에 의한 것으로 판단하였다. 흡착제의 열처리시 질소를 이용한 경우 공기에 비교하여 흡착 성능이 약 3배 이상 증가하였다. 최적 흡착제의 최대 흡착량 상수($q_m$)값은 97.07로써 기존 K 기반 첨착활성탄 대비 6배의 흡착성능이 나타났으며, 물질전달속도와 흡착속도 간 평형에 의해 객관적인 흡착량($0.3g\;g^{-1}$ 이상)이 확보됨을 확인하였다. 입자 크기에 따른 흡착제 성능 차이를 확인한 결과, 성능의 구배는 존재하나 시약급 활성탄 입자 크기를 가지는 활성탄의 개질 시에도 성능 증진이 뚜렷함을 확인하였다. 상대습도가 비교적 높은 60, 100%에서도 흡착성능이 존재함을 확인하였으며, 이를 통해 스크러버 후단과 같은 습도가 높은 실 공정에도 적용 가능할 것으로 판단된다.

• 공업화학
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• 제10권5호
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• pp.666-671
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• 1999

본 연구에서 술폰화된 poly(phenylene sulfide)(SPPS)는 10%의 발연황산으로 PPST를 술폰화한 후 NaOH 수용액으로 demethylation하여 제조하였다. 유기용매에 용해되는 PPST는 methyl-(phenylthio)phenyl sulfoxide(MPPSO)의 자가축합 반응으로 합성되었다. SPPS는 $1200cm^{-1}$에서 $-SO_{3}H$의 비대칭 O=S=O 신축진동에 의한 흡수피크와 $621cm^{-1}$에서 S-O 신축진동에 의한 흡수피크가 관찰된 것으로 보아 술폰산기가 도입된 것을 알 수 있다. PPST의 술폰화를 $150^{\circ}C$에서 12시간 반응했을 때 반복단위당 1.48개의 술폰산기가 도입되었으며, 고온 GPC로 측정된 PPST와 SPPS의 중량평균분자량(Mw)은 각각 118323과 131204이었다. SPPS의 암모니아 가스 흡착능은 $9.67mmol\;NH_{3}/g$이었고, 활성탄, 실리카겔보다 월등히 높았다.

• 자원리싸이클링
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• 제27권4호
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• pp.36-43
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• 2018

폐 니켈-카드뮴 전지의 재활용을 위하여 효율적으로 카드뮴과 니켈을 분리할 수 있도록 이온치환 반응을 이용하여 선택적으로 카드뮴을 분리하였다. 폐 니켈-카드뮴 전지 내의 전극을 분쇄하여 얻은 전극 분말을 황산에 침출시킨 니켈-카드뮴 용액에 황화나트륨을 첨가하여 CdS로 침전시켰다. 다양한 조건에서 이온치환실험을 실시하였으며, 최적조건으로는 상온에서 용액의 pH = -0.1, $Na_2S/Cd=2.3$일 때 용액 내 잔존하는 Cd은 약 100 ppm으로 대부분 CdS로 침전된 결과를 얻을 수 있었다.

• 한국대기환경학회지
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• 제24권6호
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• pp.674-681
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• 2008

Silver as a metal catalyst has been used to remove odorous compounds. In this study, silver particles in nano sizes ($5{\sim}30nm$) were prepared on the surface of $NaHCO_3$, the supporting material, using a sputtering method. The silver nano-particles were dispersed by dissolving $Ag-NaHCO_3$ into water, and the dispersed silver nano-particles in the aqueous phase was applied to remove inorganic odor compounds, $NH_3$ and ${H_2}O$, in a scrubbing reactor. Since ammonia has high solubility, it was removed from the gas phase even by spraying water in the scrubber. However, the concentration of nitrate (${NO_3}^-$) ion increased only in the silver nano-particle solution, implying that the silver nano-particles oxidized ammonia. Hydrogen sulfide in the gas phase was rapidly removed by the silver nano-particles, and the concentration of sulfate (${SO_4}^{2-}$) ion increased with time due to the oxidation reaction by silver. As a result, the silver nano-particles in the aqueous solution can be successfully applied to remove odorous compounds without adding additional energy sources and producing any harmful byproducts.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2004년도 춘계학술발표회
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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.

• 한국재료학회지
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• 제32권10호
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• pp.429-434
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• 2022

There is ongoing research to develop lithium ion batteries as sustainable energy sources. Because of safety problems, solid state batteries, where electrolytes are replaced with solids, are attracting attention. Sulfide electrolytes, with a high ion conductivity of 10^-3 S/cm or more, have the highest potential performance, but the price of the main materials is high. This study investigated lithium hydride materials, which offer economic advantages and low density. To analyze the change in ion conductivity in polymer electrolyte composites, PVDF, a representative polymer substance was used at a certain mass ratio. XRD, SEM, and BET were performed for metallurgical analyses of the materials, and ion conductivity was calculated through the EIS method. In addition, thermal conductivity was measured to analyze thermal stability, which is a major parameter of lithium ion batteries. As a result, the ion conductivity of LiH was found to be 10^-6 S/cm, and the ion conductivity further decreased as the PVDF ratio increased when the composite was formed.

• 유기물자원화
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• 제9권2호
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• pp.45-51
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• 2001

맥반석은 용액중의 철, 구리, 카드뮴과 아연 등 중금속 이온에 대해 제거효과를 나타냈으며, 그 중에서도 철과 동의 제거가 가장 뚜렷하였다. 이런 중금속의 제거는 맥반석에 포함되어 있는 칼슘 등 금속과의 이온교환에 의해 이루지는 것으로 나타났다. 맥반석은 황화수소와 암모니아 등 악취물질에 대해서도 뚜렷한 제거효과가 있으며 E. coli에 대해 항균효과가 있는 것으로 나타났다. 그리고 Nocardioides sp. PNP101를 이용한 4-nitrophenol의 분해와 Strain CJl과 Rhodococcus sp. DNP 505를 이용한 2,4-dinitrophenol의 분해를 뚜렷하게 촉진하는 것으로 나타났다.

• Asian-Australasian Journal of Animal Sciences
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• 제18권4호
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• pp.574-579
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• 2005

Optimal management of indoor air quality in a confined pig house, especially in winter, is indispensable for preventing infectious respiratory disease to workers and animals. This study was performed to elucidate the correlation of aerial contaminants and climate factors in a confinement. It was observed that indoor air contaminants ion in the confinement was the highest at 2:00-5:00 pm in a day, followed by 8:00-11:00 pm and 8:00-11:00 am. This was attributed to the increase of pig activities in the afternoon. The concentration of total dust and total airborne bacteria was found to have a significant correlation with temperature and relative humidity (p<0.05). Correlation of total dust and total airborne bacteria, total dust and ammonia, and total dust and odor were shown statistically significant at 95% confidence level. In conclusion, temperature and total dust concentration correlated significantly with all the parameters except for hydrogen sulfide ($H_2S$). This could be explained by the fact the dryness of pig feces by increase of interior temperature and resuspension of feed deposited on the floor by the pig activity, resulted in high generation of dust which adsorbed and carried the airborne bacteria and odor compounds in a confined pig house. It was proved that the adsorptive capacity of dust with ammonia ($NH_3$) was higher than that with hydrogen sulfide ($H_2S$).

• 한국대기환경학회지
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• 제15권5호
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• pp.649-655
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• 1999

Biofiltration of polluted gas streams contained $H_2S$ was studied. The experiments were performed in a laboratory-scale reactor with a porous ceramic media inoculated with sulfur oxidizing bacterium, TAS which was isolated from activiated sludge. The concentration of $H_2S$ in the inlet gas varied from 109 to 3,841 ppm, at the various space velocities(SV) of 50 $h^{-1}$ to 250 $h^{-1}$. Various tests have been conducted to evaluate the effects of such parameters as pH, concentration of sulfate ion and retention time on the pressure drop and maximum elimination capacity. The removal efficiency of $H_2S$ decreased as the $H_2S$ concentration or gas velocity increased in the inlet gas. Pressure drop was insignificant in this system. The maximum elimination capacity could reach up to 16.35g-S/kg-dry packing material/day.