• Bulletin of the Korean Chemical Society
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• 제35권3호
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• pp.913-918
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• 2014

Five mol % tungsten-doped tin oxide ($W_{0.05}Sn_{0.95}O_2$, TTO5) was prepared by co-precipitation of $SnCl_4{\cdot}5H_2O$ and $WCl_4$, followed by calcination at $1000^{\circ}C$. The as-prepared TTO5 was in the pure cassiterite phase with a particle size of ~50 nm and optical bandgap of 2.51 eV. Herein it was applied for the formation of TTO5/$TiO_2$ heterojunctions by covering the TTO5 surface with $TiO_2$ by sol-gel method. Under visible-light irradiation (${\lambda}{\geq}420$ nm), TTO5/$TiO_2$ showed a significantly high photocatalytic activity in removing gaseous 2-propanol (IP) and evolving $CO_2$. It is deduced that its high visible-light activity is caused by inter-semiconductor holetransfer between the valence band (VB) of TTO5 and $TiO_2$, since the TTO5 nanoparticle (NP) exhibits the absorption edge at ~450 nm and its VB level is located more positive side than that of $TiO_2$. The evidence for the hole-transport mechanism between TTO5 and $TiO_2$ was also investigated by monitoring the holescavenging reaction with 1,4-terephthalic acid (TA).

• 한국포장학회지
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• 제30권1호
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• pp.73-83
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• 2024

In this study, environmental evaluation of high barrier coated paper (coating layer/paper) packaging is conducted in comparison with conventional aluminum laminated (PET/VMPET/LLDPE) plastic packaging. The target product for this packaging is a KF94 mask, which requires a high barrier of water and oxygen to maintain the filtration ability of the mask filter. The functional unit of this study is 10,000 mask packaging materials based on a material capable of blocking oxygen (<1 g/m²day) and moisture (<3 g/m²day) for the preservation of KF94 masks. In order to understand the results easily, paper-based mask packaging system divided into 6 stages (pulp, pulping & paper making, calendaring & coating, printing, packing and waste management), while plastic-based mask packaging consists of 5 stages (material production, processing, printing, packing, waste management) In case of paper-based mask packaging, most contributing stage is calendaring & coating, resulting from heat and electricity production. On the other hand, plastic-based mask packaging is contributed more than 30% by material production, specifically due to linear low density polyethylene and purified terephthalic acid production. The comparison results show that global warming potential of paper-based mask packaging has 32% lower than that of plastic-based mask packaging. Most of other impact indicators revealed in similar trend.

• 청정기술
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• 제15권3호
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• pp.154-164
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• 2009

2007년을 기준으로 울산에 위치한 사업장으로부터 발생된 유기성 폐수슬러지의 94%가 해양처분되었다. 유기성 슬러지의 해양처분은 2012년에는 완전 금지될 예정이다. 그러나 아직까지 울산에 위치한 사업장으로 부터의 유기성 슬러지는 소각 이외에 다른 대안이 없는 실정이며, 현재 울산석유화학산업단지의 사업장들은 슬러지의 육상처리 및 처분기술의 확보가 매우 중요한 과제이다. 본 연구에서는 울산의 석유화학사업장 슬러지와 하수처리 슬러지를 연료로 활용하기 위해 건조슬러지와 탄화슬러지의 재료적 측면에 대한 평가를 실시하였다. 연구결과 저위발열량 3,000 kcal/kg이상을 초과하는 테레프탈산, BTX, 프로필렌, 화학섬유 등을 생산하는 사업장으로부터의 건조슬러지와 탄화슬러지는 연료로서의 가능성이 높지만 건조할 경우 2,100 kcal/kg 이하, 탄화할 경우 1,100 kcal/kg 이하인 좀 더 무기성분이 많은 펄프, 제지, 메틸아민, 아마이드 등을 생산하는 사업장의 폐수슬러지는 연료로서의 가치가 적은 것으로 나타났다. 연구결과 대부분의 슬러지들이 에너지 측면에 있어서 탄화보다는 건조가 더 좋은 결과를 보여주었다.