• Korean Chemical Engineering Research
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• v.59 no.4
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• pp.574-583
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• 2021

Waste air containing ethanol (100 ppmv) and hydrogen sulfide (10 ppmv) was continuously treated by waste air-treating system composed of two annular photocatalytic reactors (effective volume: 1.5 L) packed with porous SiO₂ media carrying TiO₂-anatase photocatalyst, one of which was alternately operated for 32 d/run while the other was regenerated by 100 ℃ hot air with 15 W UV(-A)-light on. As its elimination-behavior of ethanol, the removal efficiencies of ethanol at 1^st, 2^nd and 3^rd operation of the photocatalytic reactor system(A), turned out to be ca. 60, 55 and 54%, respectively, at their steady state condition. Unlike the elimination-behavior of ethanol, its hydrogen sulfide-elimination behavior showed repeated decrease of hydrogen sulfide removal efficiency by its resultant arrival at a lower level of steady state condition. Nevertheless, the removal efficiencies of hydrogen sulfide at 1^st, 2^nd and 3^rd operation of the photocatalytic reactor system, turned out to be ca. 80, 75 and 73%, respectively, at their final steady state condition, higher by ca. 20, 20 and 19% than those of ethanol, respectively. Therefore, assuming that adsorption on porous SiO₂-photocatalyst carrier was regarded to belong to a reversible deactivation and that decreased % of removal efficiency due to the reversible deactivation of photocatalyst including the adsorption was independent of the number of its use upon regeneration, the increments of the decreased % of removal efficiency of ethanol and hydrogen sulfide, due to an irreversible deactivation of photocatalyst, for the 3^rd use of regenerated photocatalyst, compared with the 2^nd use of regenerated photocatalyst, were ca. 1 and 2%, respectively, which was insignificant or the less than those of ca. 5 and 5%, respectively, for the 2^nd use of regenerated photocatalyst compared with the 1^st use of virgin photocatalyst. This trend of the photocatalytic reactor system was observed to be similar to that of the other alternately-operating photocatalytic reactor system.

• 한국해양학회지
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• v.28 no.3
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• pp.229-240
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• 1993

This study investigated the behaviour of sulfur species after the early diegenetic reduction of sulfate from pore solution in an anoxic intertidal flat deposit in the Banweol area of Kyeong-gi Bay, west coast of Korea. A total of seven sediment cores were collected during 1990∼1992 and were analyzed for their solid-phase sulfur species (acid-volatile sulfur, element sulfur, pyrite sulfur) as well as for chemical components in the pore solution, such as sulfate, ammonium, hydrogen sulfide, phosphate and Fe ion. The pore water sulfate oncentration was found to decrease rapidly downward from the sediment surface, while that of hydrogen sulfide, ammonium and phosphate showed and increase. The dissolved iron concentration in pore water, on the other hand, was found high in the surface layer of sediment, but fell sharply below this layer. these characteristic profiles of pore water sulfide and iron concentrations suggest that some reaction occurs between dissolved iron and sulfide ions, leading to the formation of various sulfide minerals in the sedimentary phase. The amount of inorganic sulfur species in the sediment increased downward, and showed a maximum of up to 7.9 mg/g. among the three species analyzed, acid-volatile sulfur (AVS) was dominant comprising more than 50% of the total. The amount of pyrite sulfur was greater than that of element sulfur. This implies that the formation of pyrite was restricted in this environment. the limited amount of element sulfur in this deposit may have discouraged the active formation of pyrite.

• Proceedings of the Korean Fiber Society Conference
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• 1998.04a
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• pp.338-341
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• 1998

악취의 주원인은 염기성 취기의 대표인 암모니아, 산성 취기의 대표인 황화수소, 그리고 트리메틸아민이며, 이들은 법정 악취물질로써 지정되어 있다$^1$. 이와 같은 악취를 없애는 소취기구는 활성탄 및 제오라이트 등과 같은 물질에 대한 물리적 흡착에 의한 것, 산화제 및 환원제에 의한 화학반응에 의한 것, 미생물 및 효소에 의한 생물학적 반응에 의한 것으로 대별되지만, 물리 흡착은 재방출의 문제가 있고 화학 및 생물학적 반응에는 소취성분 자체의 유해성 및 반응후 물질의 유해성이 문제가 되는 경우가 있다.(중략)

• Proceedings of the KSEEG Conference
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• 2003.04a
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• pp.53-56
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• 2003

폐광석에 함유되어 있는 중금속 원소는 물리ㆍ화학적 환경의 변화에 따라서 안정화 되어 자연적으로 정화가 진행되거나 혹은 재 용출될 수 있어 중요한 오염원으로 작용할 수 있다. 따라서 폐광석에 함유된 중금속이 흡착된 상태로 존재하는지, 광물형태(탄산염광물, 산화광물, 황산염광물 및 황화광물)로 존재하는지, 산화환경 혹은 환원환경에서 안정한 다른 광물의 결정 내에 치환된 형태로 존재하는 지를 규명하는 것은 물리화학적 환경변화에 따른 중금속의 거동(흡착반응, 탈착반응, 용해반응, 침전반응)을 예측할 수 있는 매우 유용한 평가 방법이라고 할 수 있다. (중략)

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2017.05a
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• pp.167.1-167.1
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• 2017

전이금속 디칼코게나이드는 서로 다른 전이 금속원소와 칼코겐 원소의 결합으로 이루어진 층상 구조의 물질이다. 그 중 텅스텐 이황화물($WS_2$)은 전이금속 화합물로써 풍부한 매장량으로 인하여 가격면에서 매우 저렴하며, 높은 온도에서도 잘 견딜 수 있는 열 내구성이 강해 물 분해 반응에서 촉매로 사용될 수 있는 가능성이 제시되었다. 이러한 $WS_2$을 매장량이 적은 고비용의 백금계 촉매를 대체하기 위한 물질로서 많은 연구가 활발히 진행되고 있다. 본 연구에서는 $WO_3$ 콜로이드 용액을 전기 영동 및 황화 처리 이용하여 $WS_2$를 합성하여 수소 발생 반응(Hydrogen Evolution Reaction, HER)촉매로서의 가능성을 확인하였다.

• Aerospace Engineering and Technology
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• v.11 no.2
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• pp.26-32
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• 2012

The purpose of this paper is to present the summary of trouble shooting result on the dendrite defect of SSM(Second Surface Mirror) which is one of major thermal control elements for satellite. Through this failure analysis on SSM dendrite, it is found that the dendrite defect may happen to silver coated layer of SSM if SSM is directly exposed to the environment containing sulfur or chlorine compound. As a preventive action, it is required that SSM shall not contact directly with rubber pad containing sulfur compound.

• Journal of Environmental Health Sciences
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• v.14 no.1
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• pp.11-22
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• 1988

Calcium oxide, lithium oxide and titanium oxide were investigated as additives of zinc oxide for the removal of hydrogen sulfide at high temperature. This experiment was performed in the range of 1.0-2.0 vol.% H$_2$S concentration at 623-873 K reaction temperature, using a thermogravimetric analyzer. A pore blocking model was found to fit the reaction rate and the kinetics data were sucessfully expressed by this model. The reactions between additive sorbents and hydrogen sulfide were first order with respect to hydrogen sulfide concentration in a gaseous mixture with nitrogen. Among the used sorbents, ZnO-CaO 0.5 at.% and ZnO-TiO$_2$ 2.0 at.% sorbents had the best additive effects on the sulfidation reaction between additive sorbents and hydrogen sulfide, whereas the ZnO-Li$_2$O sorbents were ineffective.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.04a
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• pp.132-136
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• 2003

폐광된 광산에 방치된 폐광석에 함유되어 있는 황화광물이 분해되어 다른 광물에 흡착되거나, 산화환경에 안정한 형태의 2차 광물로 침전 혹은 공침 되는가에 대한 연구는 광산복 원을 결정하는데 직접적인 지구화학적 자료로 활용될 수 있다. 따라서 이번 연구에서는 청양광산에 방치된 폐광석을 대상으로 XRD, SEM/EDS연구를 이용하여 산화작용으로 인한 황화광물 주변에 침전된 2차 광물에 대한 광물학적 연구를 수행하였다. 광물학적 연구 결과, 산화환경에서 황화광물의 산화작용으로 인하여 용출된 중금속 이온과 철과 망간 이온들은 침전(Fe, Mn, Pb), 공침 (Fe, Mn, As, Pb) 및 흡착(As, Cu, Pb, Zn) 등의 화학반응을 통하여 다시 고정화됨으로서, 현장에서 자연적으로 정화되고 있는 것이 확인되었다.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.15
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• pp.115-121
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• 1974

Artificial induction of nitrogen deficiency symptoms (leaf chlorosis) with two root respiratory inhibitors(DNP and Na$_2$S) was studied and regarded to be the same characteristic to red discoloration in rice var. Tongil seedling leaves as well as adult ones. Tongil(IR 667) was shown to be more nitrogen sensitive and have more distinctive appearance of the leaf discoloration than Punggwang(a native Japonica-type varity.) Conclusions were drawn from the present data that so-called red discoloration of Tongil under the natural field conditions is brought about either by insufficient nitrogen supply in soils or certain factors which may limit at any time the root absorption of nitrogen (low temperature, toxic gases or substances, poor drainage, around roots, etc.) in soils even with ample supply of it.

• Analytical Science and Technology
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• v.19 no.1
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• pp.65-72
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• 2006

In this study, the filtering characteristics of sulfur gases were investigated from a number of respects. For the purpose of this study, a standard gas containing a single oxidized S ($SO_2$) and five reduced S compounds (RSCs) including $H_2S$, $CH_3SH$, DMS, $CS_2$, and DMDS was prepared. After flowing this standard gas through a glass fiber filter, its removal efficiencies were examined by comparing the concentrations between prior to and after its passage. The results indicated that almost complete removal of $SO_2$ was achieved by this filtering, while the patterns for RSCs were distinguished by such factors as molecular weight or reactivity. It was found that about 60% of the most reactive RSC, $H_2S$ was removed by filter, while the heavy RSC generally showed removal rate of about 5% or less.