• Membrane and Water Treatment
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• 제9권5호
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• pp.327-334
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• 2018

The nano/micro composites with highly porous surface area have attracted of great interest, particularly the synthesis of porous and thin film sheets of high performance. In this paper, an easy method of cost-effective synthesis of thin film ceramic fiber membranes based on Hydroxyapatite, and activated carbon by turned into studied to be applied within the service-facilitated the transport of radioactive waste such as $^{90}Sr$, $^{137}Cs$ and $^{60}Co$) as activated product of radioisotopes from ETRR-2 research reactor and dissolved in 3M $HNO_3$, across a thin flat-sheet supported liquid membrane (TFSSLM). Radionuclides are transported from alkaline pH values. The presence of sodium salts in the aqueous media improves in $HNO_3$, the lowering of permeability because the initial $HNO_3$ concentration is improved. The study some parameters on the thin sheet ceramic supported liquid membrane. EDTA as stripping phase concentration, time of extraction and temperature were studied. The study of maximum permeability of radioisotopes for all parameters. The pertraction of a radioactive waste solution from nitrate medium were examined at the optimized conditions. Under the optimum experimental 98.6-99.9% of $^{90}Sr$, 79.65-80.3% of $^{137}Cs$ and $^{60}Co$ 45.5-55.5% in 90-110 min with were extracted in 10-30 min, respectively. The process of diffusion in liquid membranes is governed by the chemical diffusion process.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2007년도 추계학술발표회
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• pp.187-188
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• 2007

The fluctuations of biochemical and molecular activities III the harmful dinoflagellate, Cochlodinium polykrikoides, depending on water temperatures, were studied. In genomic DNA concentration, a similar value of 0.6 was shown at $12^{\circ}C$ and $15^{\circ}C$, but significantly increasing DNA from $18^{\circ}C$ (p<0.05), with a maximum of 1.8 at $24^{\circ}C$. After$24^{\circ}C$, the DNA significantly decreased to 0.6. Likely, the concentrations of RNA and total protein were at their highest values of 1.7 and 0.07 g $mL^1$ at $24^{\circ}C$, respectively. In contrast to ONA, RNA and total protein began to increase at $15^{\circ}C$. Oxygen availability between lower and higher temperatures was significantly different and increased from $18^{\circ}C$ according to light intensity, regardless of wavelengths (p<0.05). At $24^{\circ}C$, the highest value of the maximum electron transport rate (ETRmax), ranging from 537.9 (Ch 1) to 602.5 mol electrons $g^{-1}$ Ch1 a $s^{-1}$ (Ch 4), was also shown. Nitrate reductase (NR) and ATPase activities were at their highest values of 0.11 mol $NO_2^-g^{-1}$ Ch1 a $h^{-1}$ and 0.78 pmol 100 $mg^{-1}$ $at^2$ $4^{\circ}C$, respectively. When the cells cultured at $15^{\circ}C$, NR and ATPase activities significantly increased compared to $12^{\circ}C$ (p<0.05). In an analysis of CHN, the concentration of C and N also significantly increased (p<0.05). However, at $27^{\circ}C$, most of the molecular and biochemical movements were much lower, compared to $24^{\circ}C$. These results suggest that C. polykrikoides is very sensitive biochemical and molecular activities depending on water temperatures. Possibly, it is desirable to estimate at $18^{\circ}C$ the initiation of the massive blooming development of C. polykrikoides. In nature, it will be very difficult to maintain the massive blooms after $24^{\circ}C$ because of the possibility of significantly decreasing the molecular movement and activity of C. polykrikoides.

• 생명과학회지
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• 제18권9호
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• pp.1194-1201
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• 2008

본 연구는 유해성 Cochlodinium polykrikoides 적조생물을 대상으로 수온변화에 따른 세포 생화학적 및 생리 활성도를 측정했다. Genomic DNA 함량은 $12^{\circ}C$ 및 $15^{\circ}C$에서 거의 비슷한 0.6을 보였으나, $18^{\circ}C$부터 급격히 높아져서 $24^{\circ}C$ 최고 1.8를 나타내었다. RNA와 total protein도 $24^{\circ}C$에 가장 높은 1.7과 0.07 ${\mu}g$ $ml^{-1}$으로 나타났다. 광합성량도 수온에 따른 큰 변화를 보였다. 빛의 파장에 관계없이 $18^{\circ}C$ 이상에서 현저히 높은 값을 보였다. $24^{\circ}C$ $ETR_{max}$ Ch1-Ch4까지의 범위는 537.9에서 602.5 ${\mu}mol$ electrons $g^{-1}$ Chl ${\alpha}s^{-1}$ 나타났다. Nitrate reductase와 ATPase 효소 활성도는 $24^{\circ}C$에서 각각 0.11 ${\mu}mol$ $NO_{2}^{-}$ ${\mu}g^{-1}$ Chl ${\alpha}h^{-1}$ , 0.78 pmol 100 $mg^{-1}$ 나타났다. CHN 분석에서도 수온에 따라 C, H, N의 함량이 현저하게 상이했다. $27^{\circ}C$ 배양시 $24^{\circ}C$에 비하여 대부분의 세포생리물질이 낮게 보였다. 따라서 C. polykrikoides는 수온 변화에 대하여 세포대사물질의 함량이 많은 차이를 볼 수 있어서 초기 적조 발생 조건은 $18^{\circ}C$로 추측된다. 본 실험의 결과로 $24^{\circ}C$ 이상이 되면 C. polykrikoides 대번식은 세포 내 생리물질의 현저한 저하로 형성되기가 어려울 것으로 보인다.

• 대한환경공학회지
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• 제27권2호
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• pp.151-157
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• 2005

본 연구에서는 퇴적물에서 일어나는 유기물 분해과정 중 이용된 전자 수용체와 분해과정에서 생산된 환원 물질의 농도 변화를 적절히 파악하고 정량화하기 위한 수치모델을 개발하였다. 퇴적물에 서식하는 미생물이 전자 수용체를 이용하여 유기물을 분해하는 반응들은 전자 수용체의 종류에 따라서 다음과 같이 6가지 형태로 구분 할 수 있다: (1) 호기성 분해(Aerobic Respiration), (2) 탈질(Denitrification), (3) 망간 환원(Manganese Reduction), (4) 철 환원(Iron Reduction), (5) 황산염 환원(Sulfate Reduction), (6) 메탄 환원(Methanogenesis). 이와 같은 6가지 반응은 양론(Stoichiometry)적으로 표현되어지며, 여기에 관여하는 3개의 고형물질(침전성 유기물질, manganese oxides, iron oxides)과 8개의 용존물질 (oxygen, nitrate, sulfate, ammonia, dissolved manganese, dissolved iron, sulfide, methane)의 움직임은 1차원 물질수지 방정식으로 모델에서 재현되어졌다. 퇴적물에서 미생물에 의한 유기물 분해 반응은 Monod 반응식을 이용하여 간단히 표현되어졌다. 퇴적물에 포함된 물질들에 대한 물질수지 방정식들은 Monod 반응식에 포함된 비선형성을 제거하기 위해서 다단계의 반복적인 수치해석법에 의해 안정적인 해를 구할 수 있었다. 모델의 타당성을 검토하기 위하여 Sweert et al.(1991a)이 Netherland의 Veluwe 호수의 퇴적물에서 조사한 자료에 모델결과를 비교하였고, 결과로써 산출된 전자 수용체와 환원 물질의 수직적 분포형태는 관측간과 비교적 잘 부합하였다. 그러나 모델을 통하여 예측된 $NH_4^+$의 농도는 측정된 농도보다 훨씬 낮은 것이 관찰이 되었는데, 이는 모델에서 유기물질을 표현할 때 사용한 Redfield의 유기물식이 본 연구에 적용된 퇴적물에서의 높은 질소 함유율을 적절히 표현하지 못한 결과로 해석되어 질 수 있다. 퇴적물 깊이에 따른 전자 수용체와 환원된 물질의 분포변화는 중금속의 재용출과 생물이용도를 조절하는 주요인이 되기 때문에, 이 연구에서 개발된 수치모델은 퇴적물에서 일어나는 미량 오염 물질의 거동을 파악하기 위해 유용하게 사용되어질 수 있을 것으로 사료된다.

• 한국대기환경학회지
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• 제34권3호
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• pp.430-446
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• 2018

To improve understanding of the sources and chemical properties of particulate pollutants on the Korean Peninsula, An Aerodyne High Resolution Time of Flight Aerosol Mass Spectrometer (HR-ToF-AMS) measured non-refractory fine particle ($NR-PM_1$) from 2013 to 2015 at Baengnyeong Island and Seoul metropolitan area (SMA), Korea. The chemical composition of $NR-PM_1$ in Baengnyeong island was dominated by organics and sulfate in the range of 36~38% for 3 years, and the organics were the dominant species in the range of 44~55% of $NR-PM_1$ in Seoul metropolitan area. The sulfate was found to be more than 85% of the anthropogenic origin in the both areas of Baengnyeong and SMA. Ratio of gas to particle partition of sulfate and nitrate were observed in both areas as more than 0.6 and 0.8, respectively, representing potential for formation of additional particulate sulfate and nitrate. The high-resolution spectra of organic aerosol (OA) were separated by three factors which were Primary OA(POA), Semi-Volatility Oxygenated Organic Aerosol (SV-OOA), and Low-Volatility OOA(LV-OOA) using positive matrix factorization (PMF) analysis. The fraction of oxygenated OA (SOA, ${\fallingdotseq}OOA$=SV-OOA+LV-OOA) was bigger than the fraction of POA in $NR-PM_1$. The POA fraction of OA in Seoul is higher than it of Baengnyeong Island, because Seoul has a relatively large number of primary pollutants, such as gasoline or diesel vehicle, factories, energy facilities. Potential source contribution function (PSCF) analysis revealed that transport from eastern China, an industrial area with high emissions, was associated with high particulate sulfate and organic concentrations at the Baengnyeong and SMA sites. PSCF also presents that the ship emissions on the Yellow Sea was associated with high particulate sulfate concentrations at the measurement sites.