• 한국대기환경학회지
• /
• 제22권1호
• /
• pp.107-116
• /
• 2006

The main purpose of this study is to develop the greenhouse gas emission factor for power plant using bituminous coal. The power plant is a major source of greenhouse gases among the sectors of fossil fuel combustion, thus information of its emission factors is very essential to the establishment of control strategies for the greenhouse gas emissions. These emission factors derived in this study were compared with those of U. S. EPA, AGO and CCL. The $CO_{2}$ concentrations in the flue gas were measured using NDIR analyser and the GC-FID with a methanizer. The amount of carbon (C) and hydrogen (H) in fuel was measured using an elemental analyzer. Calorific values of fuel were also measured using a calorimeter. Caloric value of bituminous coal used in the power plants were 5,957 (as received basis), 6,591 (air-dried basis) and 6,960 kcal/kg (dry basis). Our estimates of carbon emission factors were lower than those of IPCC. The CO2 emission factors for the power plants using bituminous coal were estimated to be 0.791 Mg/MWh (by carbon contents and caloric value of the fuel) and 0.771 Mg/MWh (by $CO_{2}$ concentration of the flue gas). The $CO_{2}$ emission factors estimated in this study were $3.4\sim 5.4\%$ and $4.4\sim 6.7\%$ lower than those of CCL (2003) and U. S. EPA (2002).

• Journal of Microbiology and Biotechnology
• /
• 제15권4호
• /
• pp.716-721
• /
• 2005

The role of an effective microbial species is critical to the successful application of biological processes to remove sulfur compounds. A bacterial strain was isolated from the soil of a malodorous site and identified as Burkholderia spp. This isolate was able to oxidize thiosulfate to sulfate, with simultaneous pH decrease and accumulation of elemental sulfur. The specific growth rate and the sulfate oxidation rate using the thiosulfate basal medium were $0.003 h^{-1}\;and\;3.7 h^{-1}$, respectively. The isolated strain was mixotrophic, and supplementation of $0.2\%$ (w/v) of yeast extract to the thiosulfate-basal medium increased the specific growth rate by 50-fold. However, the rate of sulfate oxidation was more than ten times higher without yeast extract. The isolate grew best at pH 7.0 and $30^{\circ}C$, and the sulfate oxidation rate was the highest at 0.12 M sodium thiosulfate. In an upflow biofilter, the isolated strain was able to degrade $H_2S\;with\;88\%$ efficiency at 8 ppm and 121/h of incoming gas concentration and flow rate, respectively. The cell density at the bottom of the column reached $3.2{\times}10^8$ CFU/(g bead) at a gas flow rate of 121/h.

• Applied Biological Chemistry
• /
• 제46권2호
• /
• pp.69-73
• /
• 2003

병원에서 분리한 azole계 항진균성 항생물질에 대한 내성을 가지고 있는 Candida albicans에 대해 강한 활성을 가지는 항진균성 물질을 Bacillus subtilis LAM 97-44의 배양액으로부터 분리 정제한 후 그 특성을 조사하였다. 원심분리한 배양상등액을 butanol 추출, Diaion HP-20과 Dowex-50 adsorption chromatography, silica gel flash chromatography와 HPLC로 정제하였고 TLC와 HPLC로 확인하여 그 물질을 LAM-44A라 명명하였다. LAM-44A는 pH와 열에 매우 안정하였으며 Candida sp., Cryptococcus sp. 등에 대해 강한 활성을 나타낸 반면에 독성은 매우 적었다. 분리한 물질은 273 m에서 최대흡광도를 가진 융점 $202^{\circ}C$의 무색분말이었으며 ninhydrin 반응결과 음성이었고 $^1H-NMR$, $^{12}C-NMR$, IR spectrum, 원소분석 등의 결과로 볼 때 분자량 282의 $C_{14}H_{34}O_5$의 화학식을 가진 물질로 동정되었다.

• 분석과학
• /
• 제7권2호
• /
• pp.205-211
• /
• 1994

아세트산과 숙신산이 결합된 폴리아민-폴리우레아(CPPI와 SAPPI) 수지는 폴리에틸렌이민-폴리메틸렌폴리페닐렌 이소시안에이트(PPI) 고분자와 클로로 아세트산 또는 클로로 숙신산의 반응으로 각각 합성되었다. 이 수지들은 적외선 분광광도법 및 원소분석법으로 구조를 확인하였다. 이 수지들에 대한 3가와 6가 크롬의 흡착특성은 용액의 pH를 변화시키면서 뱃치법에 의하여 분포계수($K_d$)를 측정하여 조사하였다. 3가와 6가 크롬은 이온교환반응으로 폴리아민-폴리우레아 수지에 흡착되는 것으로 생각되었다. 이들의 최적 분리조건을 발견하고, 단지 pH를 변화시키는 단계적 용리법에 의하여 이들의 SAPPI 수지관(내경 0.6cm, 길이 10cm)으로 분리하였다. 또한 6가 크롬은 CPPI 수지관에 의하여 50배의 농축인자로 농축할 수 있다.

• 한국대기환경학회지
• /
• 제29권6호
• /
• pp.701-712
• /
• 2013

The purpose of this study is to determine concentrations and compositions of $PM_{2.5}$ and their characteristic variations at Ieodo Ocean Research Station in the East China Sea and to examine the influence of air pollutants transported from Asia continents. $O_3$ and meteorological parameters were measured since June 2003 and $PM_{2.5}$ filter samples were collected from June 2004 to June 2008. In total, 244 samples were analyzed for water soluble ions and carbonaceous compounds. The mean mass concentration of $PM_{2.5}$ and $O_3$ were $21.8{\pm}14.9{\mu}g/m^3$ and $51.6{\pm}16.1$ ppb, respectively. The average concentrations (mass fractions) of sulfate and ammonium were $6.26{\mu}g/m^3$ (28.74%) and $1.59{\mu}g/m^3$ (7.31%), respectively. Nitrate was considered to be lost through evaporation due to long stay at the station. The mean concentrations of EC and OC were $1.01{\mu}g/m^3$ and $2.34{\mu}g/m^3$, respectively, from June 2006 to June 2008. The average OC/EC ratio was 2.31. The organic matter converted from OC by multiplying 2.1 and elemental carbon constituted 22.60% and 4.66% of $PM_{2.5}$ mass, respectively.

• Journal of Microbiology and Biotechnology
• /
• 제16권11호
• /
• pp.1826-1831
• /
• 2006

A novel hyperthermophilic, anaerobic, heterotrophic archaeon, designated strain $NA1^T$, was isolated from a deep-sea hydrothermal vent area (depth, 1,650 m) within the Papua New Guinea-Australia-Canada-Manus (PACMANUS) field. Cells of this strain were motile by means of polar flagella, coccoid-shaped with a diameter of approximately $0.5-1.0{\mu}m$, and occurred as single cells. Optimal temperature, pH, and NaCl concentration for growth were $80^{\circ}C$, 8.5, and 3.5%, respectively. The new isolate was an obligate heterotroph that utilized yeast extract, beef extract, tryptone, peptone, casein, and starch as carbon and energy sources. Elemental sulfur was required for growth and was reduced to hydrogen sulfide. The G+C content of the genomic DNA was 52.0 mol%. Phylogenetic analysis of the 16S rRNA gene indicated that strain $NA1^T$ belongs to the genus Thermococcus, and the organism is most closely related to T. gorgonarius, T. peptonophilus, and T. celer; however, no significant homology was observed among species by DNA-DNA hybridization. Strain $NA1^T$ therefore represents a novel species for which the name Thermococcus onnurineus sp. novo is proposed. The type strain is $NA1^T$ (=KCTC 10859, =JCM 13517).

• 한국대기환경학회지
• /
• 제27권5호
• /
• pp.523-533
• /
• 2011

This study had the aim of characteristics of $PM_{10}$ in subway cabins. $PM_{10}$ was measured by times of day (rush and non rush hours) and seasons with real time $PM_{10}$ sampler on the subway cabins of line 7. Filter samples were collected for evaluation of their elemental composition as well as identification of major sources of $PM_{10}$ using a receptor model, PMF. $PM_{10}$ concentration were the highest in the winter season both in the rush and non rush hours at 152.8 ${\mu}g/m^3$, 90.2 ${\mu}g/m^3$ respectively. The $PM_{10}$ concentrations in rush hour were 30% higher compared to non rush hours. Based on the chemical information, the composition rare of inorganic elements was 52.5%, anions were 10.2% and others were 37.3%. Fe was the most abundant element and significantly correlated (p.0.01) with Mn (r=0.97), Ti (r=0.91), Cr (r=0.88), Ni (r=0.89) and Cu (r=0.88). Characterized $PM_{10}$ sources by PMF in the cabin were soil and road dust related sources (27.2%), railroad related sources (47.5%), secondary nitrate sources (16.2%) and a Cl-factor mixed with a secondary sulfate source (9.1%).

• 한국대기환경학회지
• /
• 제31권4호
• /
• pp.345-355
• /
• 2015

Carbonaceous compounds in the atmospheric particulate matter with an aerodynamic diameter of less than or equal to a nominal $10{\mu}m$ ($PM_{10}$) were analyzed for the samples collected during the period of August 2006 to August 2007 at Jongro in Seoul. A total 18 dicarboxylic acids (DCAs) and levoglucosan, as well as organic carbon (OC), elemental carbon (EC), and water soluble organic carbon (WSOC), were analyzed. Distinctive seasonal patterns of the concentrations of OC, EC, and WSOC including levoglucosan were observed with the highest concentrations in winter and the lowest concentrations in summer. In addition, OC, WSOC, and most of DCAs showed also higher concentration in summer than in winter. Using the seasonal patterns and relevant indicative ratios (WSOC/EC and $OC_{sec}/OC_{tot}$) of the carbonaceous compounds, it was verified that (1) primary emission sources were elevated in winter, and (2) the formation of secondary OC increased due to the prompted photochemical reaction in summer. Results from this study also suggest that some organic compounds were likely attributed to longrange transport.

• 한국대기환경학회지
• /
• 제24권4호
• /
• pp.470-482
• /
• 2008

Seasonal variations of chemical composition and optical properties of aerosols at Seoul and Gosan were investigated using the ground-based aerosol measurements and an optical model calculation. The mass fraction of elemental carbon was $8{\sim}17%$, but its contribution on light absorption was high up to $29{\sim}48%$ in Seoul. In Gosan, the contribution of water soluble aerosols on aerosol extinction was $83{\sim}94%$ due to the high mass fraction of these particles in the range of $56{\sim}88%$. Model calculation showed that the water holding capacity of aerosols was larger in Gosan than in Seoul because of higher relative humidity and temperature along with abundant water soluble aerosols. Difference between measured and calculated aerosol optical depths was the highest in summer. This was because aerosol optical depth calculated from ground-based measurements could not consider aerosol loadings at high altitude in spite of high column-integrated aerosol loadings observed by Sun photometer. Although hygroscopic growth was expected to be dominant in summer, the mass concentration of water soluble aerosols was too low to permit this growth.

• 한국대기환경학회지
• /
• 제26권1호
• /
• pp.69-76
• /
• 2010

While increased use of motor cycles in the recent years for various demands could worsen air quality, only few studies have been conducted on estimation of emission factors and characterization of emissions from motorcycle. In this study, emissions from selected six models of motorcycle based on largest market share and production rate were investigated. To investigate gaseous and carbonaceous air pollutants, such as carbon monoxide (CO), total hydrocarbon (THC), nitrogen oxide ($NO_x$), elemental carbon (EC) and organic carbon (OC), total 124 motorcycles between 2003 and 2007 model year were tested with regulatory driving conditions, such as CVS-40 and CVS-47 mode. These motorcycles were further sub-categorized based on their displacement (< 50 cc, 50~150 cc, and $\geq$ 150 cc), type of stroke (2- and 4 strokes) and model year (2003~2005 and 2006~2007). Tested motorcycles with recent model year (2006~2007) exhibited less emissions of regulatory gaseous and carbonaceous air pollutants compared to old model year (2003~2005). Chemical analysis showed that CO present in highest concentration followed by THC and $NO_x$ for all tested motorcycles. Interestingly, two strokes motorcycle produced higher THC emission but less CO and $NO_x$ than those of four strokes. For all types of displacement and stroke, emission factors (gram per kilometer) of THC and CO except $NO_x$ with recent model year (2006~2007) showed decreased trend compared to old model year (2003~2005). In addition to this, due to mixed combustion between gasoline fuel and lubricant, two strokes motorcycle showed OC > EC emission trend.