• 한국물환경학회지
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• 제26권5호
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• pp.768-774
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• 2010

This study was conducted to provide a technical solution to treat effectively perchlorate from inorganic wastewater of zinc smelting. Despite an inhibition dissolved inorganic substances in the wastewater discharged from zinc smelting has demonstrated with the activity of microbes, biological treatment technology could reduce perchlorate to a satisfactory level under such stressful conditions. It was found that either conductivity or $SO{_4}^{2-}$ concentration of the wastewater was able to be used as the adequate index and the values were $2,450{\mu}S/cm$ and 1,200 ppm respectively. When $SO{_4}^{2-}$ increased from 0 to 16,000 ppm (conductivity : $428{\rightarrow}24,800{\mu}S/cm$), perchlorate biodegradation rate was reduced due to 1/10 times from 0.0365 to 0.0033/h, however, most of perchlorate was removed under the condition of hydraulic retention time (HRT) at 0.5day and mixed liquor volatile suspended solid (MLVSS) at 2,000 ~ 3,000 ppm.

• 한국물환경학회지
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• 제23권5호
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• pp.689-696
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• 2007

Kinetic analysis was important to develope the biological nutrient removal process effectively. In this research, anoxic-anaerobic-aerobic system was operated to investigate kinetic behavior on the nutrient removal reaction. Nitrification and denitrification were important microbiological reactions of nitrogen. The kinetics of organic removal and nitrification reaction have been investigated based on a Monod-type expression involving two growth limiting substrates : TKN for nitrification and COD for organic removal reaction. The kinetic constans and yield coefficients were evaluated for both these reactions. Experiments were conducted to determine the biological kinetic coefficients and the removal efficiencies of COD and TKN at five different MLSS concentrations of 5000, 4200, 3300, 2600, and 1900 mg/L for synthetic wastewater. Mathematical equations were presented to permit complete evaluation of the this system. Kinetic behaviors for the organic removal and nitrification reaction were examined by the determined kinetic coefficient and the assumed operation condition and the predicted model formulae using kinetic approach. The conclusions derived from this experimental research were as follows : 1. Biological kinetic coefficients were Y=0.563, $k_d=0.054(day^{-1})$, $K_S=49.16(mg/L)$, $k=2.045(day^{-1})$ for the removal of COD and $Y_N=0.024$, $k_{dN}=0.0063(day^{-1})$, $K_{SN}=3.21(mg/L)$, $k_N=31.4(day^{-1})$ for the removal of TKN respectively. 2. The predicted kinetic model formulae could determine the predicted concentration of the activated sludge and nitrifier, investigate the distribution rate of input carbon and nitrogen in relation to the solid retention time (SRT).

• 한국환경농학회지
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• 제23권3호
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• pp.158-169
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• 2004

For the improvement of gas chromatographic analysis of multiple pesticide residues in green pepper, lettuce and Chinese cabbage, multiresidue test mixtures (MRTMs) of 10 groups (ECD 5 groups and NPD 5 groups) and a recovery test mixture (RTM) of 18 compounds (11 compounds for ECD and 7 compounds for NPD) were established based on retention time and response to relevant detectors. A new extraction solvent (acetone: acetonitrile=1 : 9) and a clean up eluent (hexane: dichloromethane : acetonitile = 50 : 48.5 : 1.5) for solid-phase extraction (SPE) cartridge were selected to test two types of multiresidue methods (MRM I and MRM II). MRM II provided high recovery better than MRM I when RTM was tested Recovery experiment with MRTMs which was conducted using MRM II resulted in that more than seventy percents of compounds were recovered in the range of $50{\sim}140%$, while 9% of compounds were over 140% of recovery and only $7{\sim}8$ compounds failed to detect. MRM II, an improved method, could be employed for screening residues of 190 pesticides in those vegetables.

• 한국물환경학회지
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• 제22권2호
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• pp.215-221
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• 2006

This research presents results from laboratory and pilot-scale experiments to remove high-nitrate in pickling wastewater using the sequencing batch reactor (SBR) as a biological method. During the experimental periods, the influent concentrations of NOx-N and $Ca^{+2}$ were analyzed to be 350-1,600 and 700-800 mg/L, respectively. In order to provide carbon source for denitrification, methanol has been added in proportion to the influent nitrate loading. The mean concentrations of MLSS and MLVSS, the fraction of volatile solids in sludge and the sludge volume index were measured to be 27 g/L, 5 g/L, 18.5% and 7.5, respectively. The solid retention time was kept in the range of 18 to 22 days, specific denitrification rate ($U_{dn}$) was $0.301g{NO_3}^--N/gVSS/day$. The oxidized nitrogen concentration of effluent ranged 2-34 mg/L with an average of 5.2 mg/L, the overall reduction in total nitrogen was more than 99.2%. In order to treat the pickling wastewater including the high concentration of nitrate and $Ca^{+2}$, the continuous flow process is not suitable because the specific gravity of the sludge is considerably increased by $Ca^{+2}$, thus the SBR process is shown to be very effective to treat the pickling wastewater.

• 생명과학회지
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• 제19권12호
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• pp.1698-1704
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• 2009

Gemcitabine은 다양한 고형암 치료에 사용되는 항암제이다. 혈장내에서 cytidine deaminase에 의해 빠르게 대사되며, 친수성 성질로 인해 역상 액체크로마토그라피(reversed-phase liquid chromatography)를 이용한 농도 분석이 어렵다. 본 연구에서는 역상칼럼(reversed-phase column)을 이용한 초고속 액체크로마토그라피(ultra-performance liquid chromatography, UPLC) 방법에 의해 빠르고 정확한 속력(velocity)과 최고효능(peak efficiency)를 갖춘 분석법을 개발하고자 하였다. Gemcitabine과 2'-deoxycytidine의 머무름 시간(retension time)은 293 nm에서 각각 3.2분과 2.1분이었다. 검량선의 직선성 검정은 $0.1{\sim}20{\mu}g/ml$의 농도범위에서 높은 직선성을 나타내었다($r^2$>0.999). 일내(intra-day) 변이게수(coefficients of variation)와 일간(inter-day) 변이게수는 모두 10% 이하였다. 정확성(accuracy) 검정을 위한 일내 및 일간 평균농도 측정치가 97.3~113.5% 범위로 나타났다. 이러한 결과를 토대로, gemcitabine 농도를 측정하기 위한 새로운 분석법으로 빠르고 정확한 역상 UPLC 방법을 제안하고자 한다.

• 한국습지학회지
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• 제16권3호
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• pp.363-370
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• 2014

농촌 지역 마을하수도 보급률은 도시 지역에 비해 38% 정도 수준밖에 되지 않는다. 농촌 지역은 상수원 인근에 위치하여 농촌지역에서 발생하는 하수는 상수원 오염의 원인으로 알려져 있다. 그래서 정부에서는 마을하수도 관리에 많은 노력을 기울이고 있다. 본 연구에서는 동절기 마을하수도 영양염류 제거 효율을 분석하였으며, 안동 임하댐 인근에 위치한 봉화, 영양 그리고 안동의 신설된 마을하수도를 연구 대상으로 선정하였다. 동절기 마을하수도 영양염류 제거 효율은 체류 시간과 미생물 농도에 영향을 받는 것으로 나타났다. 따라서 마을하수도 운전 시 영양염류 처리를 위해 운전 조건 조절 및 유지관리가 필요하다는 것을 의미한다.

• Journal of Microbiology and Biotechnology
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• 제22권5호
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• pp.668-673
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• 2012

Biohydrogen production from organic wastewater by anaerobically activated sludge fermentation has already been extensively investigated, and it is known that hydrogen can be produced by glucose fermentation through three metabolic pathways, including the oxidative decarboxylation of pyruvic acid to acetyl-CoA, oxidation of NADH to $NAD^+$, and acetogenesis by hydrogen-producing acetogens. However, the exact or dominant pathways of hydrogen production in the anaerobically activated sludge fermentation process have not yet been identified. Thus, a continuous stirred-tank reactor (CSTR) was introduced and a specifically acclimated acidogenic fermentative microflora obtained under certain operation conditions. The hydrogen production activity and potential hydrogen-producing pathways in the acidogenic fermentative microflora were then investigated using batch cultures in Erlenmeyer flasks with a working volume of 500 ml. Based on an initial glucose concentration of 10 g/l, pH 6.0, and a biomass of 1.01 g/l of a mixed liquid volatile suspended solid (MLVSS), 247.7 ml of hydrogen was obtained after a 68 h cultivation period at $35{\pm}1^{\circ}C$. Further tests indicated that 69% of the hydrogen was produced from the oxidative decarboxylation of pyruvic acid, whereas the remaining 31% was from the oxidation of NADH to $NAD^+$. There were no hydrogen-producing acetogens or they were unable to work effectively in the anaerobically activated sludge with a hydraulic retention time (HRT) of less than 8 h.

• 한국식품과학회지
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• 제19권4호
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• pp.361-365
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• 1987

유자의 이용성 확대를 위하여 유자원료와 유자차의 이화학적 특성, 향기성분 및 유자씨의 지방산조성을 분석하였다. 유자의 평균충량은 196g으로 이중 과즙이 18.8%, 씨 16.3%, 껍질 46.6%이고 과육이 28.3%였다. 유자원료의 당도는 $8.8^{\circ}\;Bx$, 산도 2.1%로 당산비율은 4.2이었고 유자차는 당도 $45^{\circ}\;Bx$, 산도 0.9%였다. 유자에는 fructose, glucose, sucrose가 각각 1.17%, 1.01%, 0.93% 함유되어 있으며 유자차에는 4.46%, 5.53%, 3.27%였다. 유자씨의 성분은 조지방 34.2%, 조단백 15.5% 함유되어 있고, 지방산은 palmitic acid 21.6%, stearic 3.1%, oleic 35.2%, linoleic 37.6%, linolenic이 2.6%였다. 유자의 향기성분은 limonene이 72.4%로 가장 많았으며 탄화수소류 17종, 알코올류 4종, 알데하이드 1종, 기타 6종을 포함 28종을 확인하였다.

• 한국물환경학회지
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• 제20권4호
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• pp.313-320
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• 2004

In this study, variable characteristics of drinking water and the influences on underground water reservoirs, rooftop water tanks, and service water pipes in the building were assessed. The influence of underground water reservoir material and water capacity on water quality also were assessed. The results are the following as; First of all, the drinking water passing through underground water reservoirs or service water pipes in the building, averagely metal component concentration more increased from percent of 41.3 to percent of 74.2 totally than other items of water quality. On the other hand, both residual chlorine and total solid highly decreased 65.6 percent and 35.3 percent, respectively. Therefore, it was thought that water quality could be getting worse for microorganism re-growth by residual chlorine reduction, and total solid also could be a cause for extraneous matters accumulated in water reservoir. Secondly, the variations on water quality of each stage for water supply system in the building were higher in water service pipes connected from rooftop water tanks to the tap than in underground water reservoirs. In addition to, among of twelve items on water quality, ten items on water quality except dissolved oxygen and residual chlorine increased. Therefore, it was thought that the influence of water service pipes connected from rooftop water tanks to the tap on water quality were higher than other stages of water supply system in the building. Thirdly, in case of materials of underground water reservoir, it was likely that the variation on water quality by stainless steel and concrete materials got some similar. In case of water capacity, the variations on water quality of underground water reservoirs over $1,000m^3$ higher than those under $1,000m^3$. That reasons was likely that the retention time(49.72 hours averagely) of underground water reservoirs over $1,000m^3$ was two times longer than it of those under $1,000m^3$(23.37 hours). Therefore, it was thought that the influence on water quality by materials were some similar, but in case of water capacity, the influence of underground water reservoirs were higher.

• 유기물자원화
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• 제18권3호
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• pp.50-59
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• 2010

본 연구에서는 고농도 유기성 폐기물인 음폐수와 돈분뇨를 혐기성 소화조(KH-ABC)에서 병합처리하여 대체 에너지원인 바이오가스를 생산하는 바이오가스 Pilot Plant의 성능을 검증하고 평가하였다. 그리고, 혐기성 소화 공정의 독성물질에 대한 저해 여부 가능성 및 소화액의 액비 활용 가능성에 대하여 살펴보았다. 원료 투입량, 수리학적 체류시간, 원료 배합비율(음폐수와 돈분뇨의 혼합비율) 등 운전조건의 변화에 따른 유기물(VS) 분해율, 바이오가스 생산량 및 메탄농도 등을 분석한 결과 원료의 유기물부하가 증가($1.2{\sim}2.0kg-VS/m^3{\cdot}d$)함에 따라 투입 유기물 당 바이오가스 생산량은 $0.60{\sim}0.69m^3/kg-VS_{input}$로 증가하는 경향을 보였다. 특히 원료투입량 $6m^3$/일, 원료배합비율 음폐수:돈분뇨=4:6, 수리학적 체류시간(HRT) 25일의 조건에서 유기물 분해율 70%, 바이오가스 생산량 $220m^3$/일, 메탄농도 64%로 비교적 높은 성능을 나타냈다. 그리고, 소화액을 분석한 결과 혐기성 소화공정에 저해 작용을 유발하는 양이온 및 중금속 등의 독성물질은 기준농도 이하로 존재하였으며, 소화액(원료배합비율 음폐수:돈분뇨=3:7)은 액비 활용기준인 비료공정규격을 만족하였다.