2009/6 VOL.09
광주과학기술원 환경복원 연구실
안녕하세요. 환경복원 연구실입니다. 유난히 더운 여름이 다가온다고 하니 미리 몸 건강에 유의 하셔야겠습니다. 이번 호에서도 동일하게 본 연구실에서 연구하는 나노 기술을 이용한 오염물질 제거의 관한 정보와 2009년 전반기 동안의 실험실 소식을 나누려고 합니다. 무척이나 더운 여름에 몸 건강하시고 다음 호에 좋은 모습으로 찾아 뵙겠습니다.
02 02 인사말
03 Special News
04 논문게재
07 복원연구실 연구주제
발행인 최희철 (hcchoi@gist.ac.kr), 편집인 김요한(wdd20@gist.ac.kr)
08 연구실 소식/ 논문실적
09 국내/국제 학술대회
• Special News • 논문게재 1 • 논문게재 2 • 논문게재 3 • 복원연구실 연구주제
최희철 교수 세계물협회 (IWA) 국제프로그램위원회 위원 선출 및 국외 학회에 초청연사로 강연
최희철 l 광주과학기술원 환경공학과 교수
본 연구실 최희철 교수님께서 세계물협회 (IWA) 국제프로그램위원회 (International
Program Committee) 위원에 선출되셨습니다. IWA 프로그램 위원회는 IWA 최고위위원회 중 하나로 2년마다 있는 세계물학술회의 (World Water Congress) 개최국 선정과 학술회의 프로그램을 결정하는 역할을 하고 있으며 전세계 지역, 국가별 대표자 15인으로 구성됩니다. 최희철 교수님께서는 4년간 위원으로 활동하며 금년 4월 네덜란드 헤이그에서 2010 몬트리올 세계물학술회의 프로그램선정 회의에 참석하셨습니다. 또한, 작년에 미국 환경 보호국(EPA)와 대한환경공학회에서 Keynote Speaker로 초청되어 발표한 데 이어 올해에도 대만에서 열린 “The 6th Conference on environmental
protection and nanotechnology”학회에서 Invited talk 로초빙되어“Environmental 의 주제로 발표하셨습니다. nanotechnology: Application and Implication” 이미 여러 국제 학술지에서 편집위원으로 활동하고 계신 교수님께서 이번에 협회 프로그램 위원 및 학회 Keynote Speaker 등 다방면으로 활동의 폭을 더 넓히시고 계십니다. 활발한 연구로 국내외에서 선두자의 입지를 굳게 다지고 계시는 최희철 교수님께서는 “세월이 살같이 흘러 환경나노기술이라는 새로운 도전 적인 주제로 연구를 시작한지 엊그제 같은데 벌써 5년이란 세월이 지났다. 연구에 매진해서 많은 실적을 쌓았고 새로운 분야 개척자라는 자부심도 얻었다”며 솔직한 소감을 표현하셨습니다.
김요한 (광주과학기술원 환경공학과, wdd20@gist.ac.kr)
• Special News • 논문게재 1 • 논문게재 2 • 논문게재 3 • 복원연구실 연구주제
04
Environmental Science and Technology Vol. 43, 3292-3299, 2009
Aqueous ethanol modified nanoscale zerovalent iron in bromated reduction: Synthesis, Characterization, and Reactivity
Qiliang Wang, Shane Snyder, Jungwoo Kim and Heechul Choi Nanoscale zerovalent iron (NZVI) was evaluated for the reduction of bromate that is a highly persistent and carcinogenic oxyhalid formed as an ozonation byproduct during oxidative disinfection in drinking water treatment. Solidphase NZVI with different surface areas was controllably synthesized using a liquid phase reduction. Transmission electron microscopy (TEM), X-ray diffraction (XRD), and a Brunauer−Emmett−Teller (BET) surface area and porosity analyzer were utilized to characterize particle size, surface morphology, surface area, and corrosion layers formed onto NZVI before and after the reduction of bromate. Surface area of synthesized NZVI was found to be influenced strongly by ethanol contents during synthesis with a maximum surface area of 67.51 ± 0.35 m2/g in a 90% aqueous ethanol; additionally, capsule structures of NZVI with amorphous phase, in which tens of particles with diameters of 2−5 nm were packed into an iron oxide/hydroxide layer, were also synthesized using 100% ethanol as a solvent. Subsequent XRD and TEM results revealed that in a 20 min bromate reduction NZVI mostly converted to Fe2O3 and Fe3O4 corrosion products mixed with iron hydroxides. Compared to bromate reduction using microsized ZVI in a pseudo-first-order kinetic model, NZVI enhanced the reduction efficiency following a secondorder kinetic model, with observed second-order rate constants (kobs) of 2.57 × 10−4 to 2.19 × 10−3 μg−1min−1L. Humic acid was found to be the most influencing factor to decrease NZVI reactivity in bromate reduction. However, the effect of sonication pretreatment showed that the bromate reduction efficiency could be enhanced by increasing the actual reactive surface area. Our results suggest that application of NZVI is a viable process for bromate reduction in water treatment. Bromate reduction using NZVI 3 from raw and treated Colorado River water: KBrO3 is 100ppb, at pH 7 and 20.
• Special News • 논문게재 1 • 논문게재 2 • 논문게재 3 • 복원연구실 연구주제
Applied Physics Letters, Vol. 94, 073306, 2009
Improved performance of polymer light-emitting diodes with nanocomposites
A. Mohammed Hussain, B. Neppolian, Sun Hee Kim, Jin Young Kim, Hee-Chul Choi, Kwanghee Lee, Seong-Ju Park, and Alan J. Heeger The characteristics of a hybrid polymer light-emitting diode (HPLED) with an active layer of poly [2-methoxy,5-(2-ethylhexoxy)-1,4-phenylenevinylene] blended with Au-capped TiO2 nanocomposites are reported. Both the increased current in the active layer and low turn-on voltage were attributed to incorporation of Au-capped TiO2 in the electroluminescent polymer. The maximal brightness of 11630 cd/m2 was observed in HPLED with a 1:1 ratio of Au-capped TiO2. The enhanced performance was attributed to the roughness assisted charge transport induced by the Au-capped TiO2 nanocomposites in the active polymer.
(Color online) (a) Schematic diagram of the HPLED with Au-capped TiO2 nanocomposites.
• Special News • 논문게재 1 • 논문게재 2 • 논문게재 3 • 복원연구실 연구주제
06
Water Science & Technology, 59, 12, 2437-2446, 2009
Effect of environmental flow management on river water quality: a case study at Yeongsan River, Korea
Sung Min Cha, Seo Jin Ki, Kyung Hwa Cho, Heechul Choi and Joon Ha Kim This paper describes a management scheme to control river water quality using additional water discharges from upstream dams, which results in an increase environmental flow (EF) followed by an enhancement of water quality in a target river. To suggest a creditable management plan among a suite of ideal scenarios, the monthly averaged water quality monitoring data from 2001 to 2006 at the Yeongsan (YS) River, Korea were investigated with respect to seasonal variation and spatial distribution. From the analysis, it was found that while biochemical oxygen demand (BOD5) level in the YS River was extremely high during the dry/drought season (April, May, and June; AMJ), the level was subsequently decreased during the monsoon season (July, August, and September; JAS) due mainly to the dilution effect of rainfall. To improve the water quality in AMJ, we here suggested a scenario of increasing EF using surplus water discharges from upstream dams, which was examined by one dimensional riverine water quality model, QUAL2E model. Simulation result showed that additional discharge from the upstream dams could lead, on average, to a 36% of water quality improvement in mainstream with respect to BOD5. Model coefficients were validated by comparing the six year monitoring data to minimize a sum of squares error, and showed a good agreement with the observed data. Overall, the methodology developed in this paper appears to be quite clear and straightforward, and thus, can be applied to a wide range of the flow managements or water quality controls in a stream with artificial structures.
• Special News • 논문게재 1 • 논문게재 2 • 논문게재 3
Priority themes have been identified by ERL:
• 복원연구실 연구주제
1. Synthesis of granulized mesoporous material for conventional water treatment 2. Fate and transport of nanoparticles in visualized micro model 3. Reactive ceramic membrane incorporated with iron oxide nanoparticles for water treatment 4. Removal of pharmaceuticals of EDCs using (functionalized) mesoporous silica/metal oxides/carbonaceous materials 5. NZVI(Nanosized Zero Valent Iron) and Bimetallic NZVI for bromate & nitrate reduction 6. Synthesis, characterization and application of CNT blended polymeric membranes 7. Horizontal collector well efficiency Evaluation through modeling in RBF (Riverbed Filtration)
연구실 소식 최희철 교수님께서 세계물협회 (IWA) 국제프로그램위원회 (International Program Committee) 위원에 선출되셨습니다. 최희철 교수님께서 5월 대만에서 열린 The 6th Conference on Environmental
Protection and Nanotechnology 학회에 keynote speaker로 초청되어 발표하였습니다. 본 연구실 소속인 박사과정 박호식, Bui Xuan Tung 학생이
American Society of Civil Engineers (ASCE)에서 출판한 Nanotechnology for Water Environment Applications 책에서 Chapter 2 “Synthesis of Nanoparticles and One-Dimensional Nanomaterials”, Chapter 10 “Nanoscale Carbon Materials for Contaminant Separation” 부분을 집필하였습니다.
논문실적 Qiliang Wang, Shane Snyder, Jungwoo Kim and Heechul Choi Aqueous ethanol modified nanoscale zerovalent iron in bromated reduction: Synthesis, Characterization, and Reactivity, Environmental Science and Technology Vol. 43, 3292-3299, 2009 A. Mohammed Hussain, B. Neppolian, Sun Hee Kim, Jin Young Kim, Hee-Chul Choi, Kwanghee Lee, Seong-Ju Park, and Alan J. Heeger
08
Improved performance of polymer light-emitting diodes with nanocomposites, Applied Physics Letters, Vol. 94, 073306, 2009 Sung Min Cha, Seo Jin Ki, Kyung Hwa Cho, Heechul Choi and Joon Ha Kim Effect of environmental flow management on river water quality: a case study at Yeongsan River, Korea, Water Science & Technology, 59, 12, 2437-2446, 2009
국제 학술대회 Heechul Choi (Invited talk) Environmental Nanotechnology: Application and Implication The 6th Conference on Environmental Protection and Nanotechnology, May 20–22, Kaohsiung, Taiwan, 2009
국내 학술대회 김요한, 최희철 Mesoporous materials by supported nano-sized iron-oxide: preparation, characterization and applications for removal of natural organic matter (NOM) 대한환경공학회, 창원, Apr. 30-May 1, 2009
김영애, 최희철 Removal of arsenite by a two-step process of oxidation and adsorption on iron oxide impregnated granular activated carbon 대한환경공학회, 창원, Apr. 30-May 1, 2009
Evrim Celik and Heechul Choi Carbon nanotube/Polyethersulfone blend membranes 대한환경공학회, 창원, Apr. 30-May 1, 2009
Qiliang Wang and Heechul Choi Aging study on the structure of Fe0-nanoparticles stabilized using inert gases: characterization and reactivity 대한환경공학회, 창원, Apr. 30-May 1, 2009
09
김정우, 임훈철, 최희철, Yakov A. Pachepskya 하상여과에서 바이오필름에 의한 공극매질 막힘현상에 관한 연구 대한환경공학회, 창원, Apr. 30-May 1, 2009
김영애, Bernaurdshaw Neppolian, 최희철 Removal of Arsenite by Iron Oxide Impregnated Granular Activated Carbon: Effects of Anions and Humic Acid
한국화학공학회, 광주 , Apr. 22-24, 2009
Department of Environmental Science and Engineering Gwangju Institute of Science and Technology 1 Oryong-dong, Buk-gu, Gwangju 500-712, Korea. Tel. 062-715-2576 l Fax. 062-715-2434 l Homepage. erl.gist.ac.kr