Polyvanadate dominant vanadia–alumina composite aerogels prepared by a non-alkoxide sol–gel method

Choi, Jinsoon,Shin, Chee Burm,Suh, Dong Jin Royal Society of Chemistry 2009 Journal of materials chemistry Vol.19 No.41

<P>Vanadia–alumina composite aerogels were synthesized by a cogelation method using alcoholic solutions of metal chlorides under acidic conditions. The resulting aerogels exhibited high surface areas and narrow pore size distributions in the mesoporous region. The vanadium oxides existing on the surface of the aerogels predominantly developed into polyvanadates in terms of chemical structure following the introduction of V species up to 40 wt.% with 500 °C calcination. The intensities of the Raman spectra for the polyvanadates increased with vanadia content, while Raman bands shifted towards lower wavenumbers with decreasing vanadia content due to weak V–O bonds. Homogeneity of the surface vanadates on the aerogels was much higher than that on the impregnated materials, as observed in temperature programmed reduction and NH<SUB>3</SUB> temperature programmed desorption patterns.</P> <P>Graphic Abstract</P><P>Vanadia–alumina composite aerogels were synthesized by a cogelation method using alcoholic solutions of metal chlorides under acidic conditions and subsequent supercritical drying. The vanadium oxides existing on the surface of the aerogels predominantly developed into polyvanadates in terms of chemical structure following the introduction of V species up to 40 wt.% with 500 °C calcination. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=b905435a'> </P>

Complete oxidation of 1,2-dichlorobenzene over V2O5-TiO2 and MnOx -TiO2 aerogels

Jinsoon Choi,서동진 한국화학공학회 2014 Korean Journal of Chemical Engineering Vol.31 No.10

Catalytic destruction of 1,2-dichlorobenzene was carried out over two types of aerogels, vanadia-titaniaand manganese oxide-titania. Reactions were performed in a plug flow reactor in the range of 150-600 oC. Both catalystsresulted in very high selectivity to carbon oxides and produced negligible amount of hydrocarbon byproducts. Overthe vanadia-titania catalysts, the chlorinated compound was relatively more efficiently destructed at lower tempera-ture, while selectivity towards carbon dioxide was much higher over manganese oxide-titania aerogel catalysts. Vanadia-titania catalysts, regardless of the preparation methods, showed a tendency to produce carbon monoxide with 35-45%selectivity throughout the reaction temperature range while manganese oxide-titania exhibited more than 90% CO2selectivity at above 400 oC.

Effects of preparation methods for V2O5-TiO2 aerogel catalysts on the selective catalytic reduction of NO with NH3

강민,Jinsoon Choi,김용태,박은덕,신치범,서동진,이재의 한국화학공학회 2009 Korean Journal of Chemical Engineering Vol.26 No.3

A series of V2O5-TiO2 aerogel catalysts were prepared by the sol-gel method with subsequent supercritical drying with CO2. The main variables in the sol-gel method were the amounts of V2O5 and when the vanadium precursor was introduced. V2O5-TiO2 xerogel and V2O5/TiO2 (P-25) were also prepared for comparison. The V2O5-TiO2 aerogel catalysts showed much higher surface areas and total pore volumes than V2O5-TiO2 xerogel and impregnated V2O5/TiO2 (P-25) catalysts. The catalysts were characterized by N2 physisorption, X-ray diffraction (XRD), FT-Raman spectroscopy, temperature-programmed reduction with H2 (H2-TPR), and temperature-programmed desorption of ammonia (NH3-TPD). The selective catalytic reduction of NOx with ammonia in the presence of excess O2 was studied over these catalysts. Among various V2O5-TiO2 catalysts, V2O5 supported on aerogel TiO2 showed a wide temperature window exhibiting high NOx conversions. This superior catalytic activity is closely related to the large amounts of strong acidic sites as well as the surface vanadium species with characteristics such as easy reducibility and monomeric and polymeric vanadia surface species.

GIS기반 적지분석을 통한 조류-양수 융합발전시스템 설치후보지 도출 연구

이철용 ( Cholyoung Lee ),최현우 ( Hyun-woo Choi ),박진순 ( Jinsoon Park ),김지훈 ( Jihoon Kim ),박준석 ( Junseok Park ) 한국지리정보학회 2020 한국지리정보학회지 Vol.23 No.4

본 연구에서는 GIS기반 적지분석을 적용하여 조류-양수 융합발전시설의 설치후보지역을 도출하는 것을 목표로 하였다. 연구대상지역은 진도 일대 서남해 해역이며, 융합발전시설의 설계 및 설치 특성을 고려하여 적지분석을 위한 고려인자를 도출하였다. MOHID(Modelo HIDrodinâmico)를 이용하여 조류 수치모의를 수행하였고, 모의 결과를 공간자료로 변환하였다. 이후 본 연구에서는 제안하는 GIS기반 중첩분석 방법을 적용하여 설치후보지역을 도출하였다. 연구 결과에서 총 10개 지역이 후보지역으로 도출되었으며, 이 중 진도, 성남도, 하조도가 상대적으로 넓은 해역에 대해 조류-양수 발전기 설치가 가능한 것으로 판단되었다. This study aimed to determine candidate areas for tidal current-pumped storage hybrid power plants using GIS-based site selection analysis. The study area is the southwestern sea surrounding Jindo Island in South Korea. Factors to be considered for the site selection analysis were derived considering the design and installation characteristics of the hybrid power plant. Numerical simulation to predict tidal speed was performed using the MOHID(Modelo HIDrodinâmico) and the results were converted into spatial data. Subsequently, a GIS-based overlay analysis method proposed in this study was applied to derive the installation candidate area. A total of 10 regions were identified as candidate sites. Among them, it was determined that the power generator could be installed in relatively wide sea areas in Jindo, Seongnamdo, and Hajodo.

대한민국 서남해 갯벌내 유기탄소 저장량 및 연간 탄소침적률 산정

이종민(Jongmin Lee),권봉오(Bong-Oh Kwon),류종성(Jongseong Ryu),박진순(Jinsoon Park),홍성진(Seongjin Hong),이숙희(Sukhui Lee),김성길(Seong-Gil Kim),손수진(Sujin Son),윤훈주(Hoon Joo Yoon),남정호(Jungho Nam),최경식(Kyungsik Choi),김종성(J 한국해양환경·에너지학회 2021 한국해양환경·에너지학회 학술대회논문집 Vol.2021 No.5

블루카본 연구에서 퇴적물 내 유기탄소 저장량과 연간 유기탄소 침적률의 산정은 필수적이나, 현재 한국 갯벌에서의 국가적 규모의 연구는 부족한 실정이다. 본 연구에서는 현장조사 자료와 원격탐사기법을 이용하여 서남해 갯벌의 유기탄소 저장량과 연간 유기탄소 침적률을 추산하였다. 조사지역은 서남해 6개 시도(경기, 인천, 충남, 전북, 전남, 경남)내 20개 지역이었으며, 2017년부터 2019년까지 총 289개의 코어퇴적물(깊이=0.6-1.0m)을 채취 및 분석하였다. 그리고 원격탐사기법을 통해 서남해 갯벌의 퇴적물 성상과 면적을 추산하였다. 코어퇴적물 분석결과, 니질함량은 전 지역에 걸쳐 퇴적물 내 유기탄소 함량을 예측하는 주요한 환경 변수였으며, 총 유기탄소 함량과 양의 상관관계(p < 0.05)를 나타냈다. 염습지에서는 염생식물의 일차생산을 통한 높은 탄소고정 능력으로 인해, 비식생 갯벌보다 상대적으로 높은 유기탄소 저장량을 보였다. 또한, 인공위성 영상분석을 통한 퇴적물 성상분류는 니질함량 분석에 의한 퇴적물 성상분류 결과와 대체적으로 유사하였다(p < 0.05). 현장조사와 인공위성 분석을 통해 서남해 갯벌의 총 유기탄소 저장량 13,939,020 Mg C, 연간 유기탄소 침적률 75,367 Mg C yr^-1을 추산하였다. 본 자료는 처음으로 한국 서남해 갯벌의 블루카본 잠재량을 국가 규모로 조사하였으며, 향후 한국 조간대 퇴적물 내 탄소순환 연구에 대한 중요한 기초자료로써 활용될 수 있을 것으로 사료된다. Blue carbon studies require estimates of organic carbon stocks and sequestration rates; however, holistic data analyses remain limited in South Korea, particularly at national scale. The present study reports current organic carbon stocks and sequestration rates in the coastal areas of Korea, encompassing the entire tidal flats, by long-term field survey combined with remote sensing approach. Target areas included 20 intertidal flats across five provinces in South Korea (Gyeonggi, Chungnam, Jeonbuk, Jeonnam, Gyeongnam). Out of the evaluated environmental parameters, mud content represented a significant factor controlling sedimentary organic carbon stocks across target areas, and was significantly positively correlated to total organic carbon (p < 0.05). Organic carbon stocks measured in the salt marshes, say upper intertidal zone, reflected the high carbon fixation capacity of halophytes through primary production. Sediment textural types were classified using remotely sensed imagery, and was closely correlated with the experimental classification results (p < 0.05). Using field and satellite measurements, we could estimate total organic carbon stocks (13,939,020 Mg C) and sequestration rates (75,637 Mg C yr^-1) in South Korea at national scale. The present study first report the blue carbon potentials of the Korean tidal flats at national scale and provides baseline information on the carbon dynamics of intertidal sediments in Korea and elsewhere.

Impacts of environmental and anthropogenic stresses on macrozoobenthic communities in Jinhae Bay, Korea

Bae, Hanna,Lee, Jung-Ho,Song, Sung Joon,Park, Jinsoon,Kwon, Bong-Oh,Hong, Seongjin,Ryu, Jongseong,Choi, Kyungsik,Khim, Jong Seong Elsevier 2017 CHEMOSPHERE - Vol.171 No.-

<P><B>Abstract</B></P> <P>In this study, spatiotemporal dynamics of macrofaunal assemblages and their associations with environmental conditions were examined in Jinhae Bay (10 sites), where the obvious sources of pollution including industries, oyster farms (hanging cultures), and municipal discharges has surrounded. The survey had performed over five consecutive seasons in 2013–2014. Target sedimentary variables included grain size, organic content, C/N ratio, carbon and nitrogen stable isotope ratios, and some heavy metals. Five ecological quality indices (EcoQ) were calculated from the benthic community data to evaluate ecological qualities in site-specific manner. Jinhae Bay is a shallow (depths range, 11–24 m) and typical semi-enclosed bay. The benthic environments represented mud dominated bottoms (>70%) with fairly substantial organic content levels (>2%) over all five seasons. Seasonal patterns were observed with peak abundances in the spring and distinctive macrozoobenthos species shifts in the summer. The spring bloom could be explained by drastic increases of some polychaetes, mainly <I>Capitella</I> sp., at certain site, particularly near the shore. The oyster farms situated in the innermost locations seem to provide organic-rich bottoms being dominated by opportunistic species and/or organic pollution indicator species, such as <I>Lumbrineris longifolia</I>, <I>Capitella</I> sp., and <I>Paraprionospio patiens</I>. In general, the EcoQ indicators indicated that Jinhae Bay was moderately polluted, with exceptionally poor EcoQ in a few locations during the specific season(s). Overall, adverse effects on benthic community was broadly attributable to contaminations of heavy metals and nearby aquatic farm activities in Jinhae Bay, which requires a prompt action toward ecosystem-based management practice in the given area.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Spatiotemporal dynamics of macrofaunal assemblages in Jinhae Bay were addressed. </LI> <LI> Peak abundances in spring and distinctive species shifts in summer were characteristic. </LI> <LI> Oyster farming was one potential anthropogenic stress affecting macrofaunal communities. </LI> <LI> Analysis of five ecological quality indices indicated moderate pollution in given area. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Two Years after the <i>Hebei Spirit</i> OilSpill: Residual Crude-Derived Hydrocarbons and Potential AhR-MediatedActivities in Coastal Sediments

Hong, Seongjin,Khim, Jong Seong,Ryu, Jongseong,Park, Jinsoon,Song, Sung Joon,Kwon, Bong-Oh,Choi, Kyungho,Ji, Kyunghee,Seo, Jihyun,Lee, Sangwoo,Park, Jeongim,Lee, Woojin,Choi, Yeyong,Lee, Kyu Tae,Kim, AmericanChemical Society 2012 Environmental science & technology Vol.46 No.3

<P>The <I>Hebei Spirit</I> oil spill occurredin December2007 approximately 10 km off the coast of Taean, South Korea, on theYellow Sea. However, the exposure and potential effects remain largelyunknown. A total of 50 surface and subsurface sediment samples werecollected from 22 sampling locations at the spill site in order todetermine the concentration, distribution, composition of residualcrudes, and to evaluate the potential ecological risk after two yearsof oil exposure. Samples were extracted and analyzed for 16 polycyclicaromatic hydrocarbons (PAHs), 20 alkyl-PAHs, 15 aliphatic hydrocarbons,and total petroleum hydrocarbons using GC-MSD. AhR-mediated activityassociated with organic sediment extracts was screened using the H4IIE-<I>luc</I> cell bioassay. The response of the benthic invertebratecommunity was assessed by mapping the macrobenthic fauna. Elevatedconcentrations of residual crudes from the oil spill were primarilyfound in muddy bottoms, particularly in subsurface layers. In general,the bioassay results were consistent with the chemistry data in adose-dependent manner, although the mass-balance was incomplete. Moreweathered samples containing greater fractions of alkylated PAHs exhibitedgreater AhR activity, due to the occurrence of recalcitrant AhR agonistspresent in residual oils. The macrobenthic population distributionexhibits signs of species-specific tolerances and/or recolonizationof certain species such as <I>Batillaria</I> during weatheringperiods. Although the <I>Hebei Spirit</I> oil spill wasa severe oil exposure, it appears the site is recovering two yearslater.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/esthag/2012/esthag.2012.46.issue-3/es203491b/production/images/medium/es-2011-03491b_0001.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/es203491b'>ACS Electronic Supporting Info</A></P>