• Applied Biological Chemistry
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• 제34권4호
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• pp.299-306
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• 1991

$[U-^{14}C]\;TCAB$를 $MM_2$ 무기배지(無機培地)에 유일(唯一)한 탄소원(炭素源)으로 첨가(添加) 후(後) 분리(分離)한 균주(菌株)들을 순수배양(純粹培養)하였을 때 약간(若干)의 방사성(放射性) 분해산물(分解産物)이 autoradiography에 의(依)하여 검출(檢出)되었다. 또한 유기물(有機物)을 제거한 토양(土壤)에 $^{14}C-TCAB$를 첨가(添加)한 후(後) 각각의 분리균주(分離菌株)들을 접종(接種)하고 $MM_2$ 무기배지(無機培地)를 가(加)하여 일정(一定)한 습도(濕度)를 유지(維持)하면서 $30^{\circ}C$에서 배양(培養)하였을 때 $^{14}CO_2$가 발생(發生)되지 않았다. 이들 분리균주(分離菌株)의 하나인 Achromobacter group VD를 순수배양(純粹培養) 시(時) m/z 250인 분해산물(分解産物)이 GC/MS에 의(依)하여 확인(確認)되었다. 이 분해산물(分解産物)의 가능(可能)한 형성경로(形成經路)는 TCAB의 구조(構造)로부터 dechlorination, hydrorylation, 2개(個) benzene환(環)의 ortho 관열(關裂), 그리고 생성(生成)된 carboxyl group의 환원(還元) 등이 관련(關聯)된다고 생각된다.

• 상하수도학회지
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• 제23권6호
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• pp.743-752
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• 2009

One of the major problems associated with operation of domestic sewer lines involves hydraulic problems such as insufficient conveyance capacity, exceeding maximum velocity, and deficiency of minimum velocity. It has also been pointed out that influent concentration lower than design concentration of pollutants, which is mainly caused by unidentified inflow and infiltration, degrades the operational efficiency of many sewage treatment plants (STPs). A computer-added analysis method supporting a coupled simulation of sewage quality and quantity is essentially required to evaluate the status of existing STPs and to improve their efficiency by a proper sewer rehabilitation work. In this study, dynamic water quality simulations were conducted using MOUSE TRAP to investigate the principal parameters that governs the changes of BOD, ${NH_4}^+$, and ${PO_4}^{3-}$3- concentrations within the sewer networks based on data acquired through on-site and laboratory measurements. The BOD, ${NH_4}^+$ and ${PO_4}^{3-}$3- concentrations estimated by MOUSE TRAP was lower than theoretical pollution loads because of sedimentation and decomposition in the sewer. The results revealed that sedimentation is a most important factor than other biological reactions in decreasing pollutant load in the sewers of C-city. The sensitivity analysis of parameters pertaining to water quality changes indicated that the effect of the BOD decay rate, the initial DO concentration, the half-saturation coefficient of dissolved BOD, and the initial sediment depth is marginal. However, the influence of settling rate and temperature is relatively high because sedimentation and precipitation, rather than biological degradation, are dominant processes that affect water quality in the study sewer systems.

• 한국농공학회지
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• 제32권E호
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• pp.1-19
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• 1990

Abstract Over the last several decades, crop production in the United States increased largely due to the extensive use of animal waste and fertilizers as plant nutrient supplements, and pesticides for crops pests and weed control. Without the application of animal waste best management, the use of animal waste can result in nonpoint source pollution from agricultural land area. In order to increase nutrient levels and decrease contamination from agricultural lands, nonpoint source pollution is responsible for water quality degradation. Nonpoint source pollutants such as animal waste, ferilizers, and pesticides are transported primarily through runoff from agricultural areas. Nutrients, primarily nitrogen and phosphorus, can be a major water quality problem because they cause eutrophic algae growth. In 1985, it was presented that Watershed/Water Quality Monitoring for Evaluation BMP Effectiveness was implemented for Nomini Creek Watershed, located in Westmoreland County, Virginia. The watershed is predominantly agricultural and has an aerial extent of 1505 ha of land, with 43% under cropland, 54% under woodland, and 3% as homestead and roads. Rainfall data was collected at the watershed from raingages located at sites PNI through PN 7. Streams at stations QN I and QN2 were being measured with V-notch weirs. Water levels at the stream was measured using an FW-l Belfort (Friez FWl). The water quality monitoring system was designed to provide comprehensive assessment of the quality of storm runoff and baseflow as influenced by changes in landuse, agronomic, and cultural practices ill the watershed. As this study was concerned with the Nomini Creek Watershed, the separation of storm runoff and baseflow measured at QNI and QN2 was given by the master depletion curve method, and the loadings of baseflow and storm runoff for TN (Total Nitrogen) and TP (Total Phosphorus) were analyzed from 1987 through 1989. The results were studied for the best management practices to reduce contamination and loss of nutrients, (e.g., total nitrogen and total phosphorus) by nonpoint source pollution from agricultural lands.

• Molecular & Cellular Toxicology
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• 제5권3호
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• pp.179-186
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• 2009

Hexachlorobenzene (HCB) is a bioaccumulative, persistent, and toxic pollutant. HCB is one of the 12 priority of Persistent Organic Pollutants (POPs) intended for global action by the United Nations Environment Program (UNEP) Governing Council. POPs are organic compounds that are resistant to environmental degradation through chemical, biological, and photolytic processes. Some of HCB is ubiquitous in air, water, soil, and biological matrices, as well as in major environmental compartments. HCB has effects on various organs such as thyroid, bone, skin, kidneys and blood cells and especially, revealed strong toxicity to liver. In this study, we identified genes related to hepatotoxiciy induced by HCB in human hepatocellular carcinoma (HepG2) cells using microarray and gene ontology (GO) analysis. Through microarray analysis, we identified 96 up- and 617 down-regulated genes changed by more than 1.5-fold by HCB. And after GO analysis, we determined several key pathways which known as related to hepatotoxicity such as metabolism of xenobiotics by cytochrome P450, complement and coagulation cascades, and tight junction. Thus, our present study suggests that genes expressed by HCB may provide a clue for hepatotoxic mechanism of HCB and gene expression profiling by toxicogenomic analysis also affords promising opportunities to reveal potential new mechanistic markers of toxicity.

• 보존과학회지
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• 제30권1호
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• pp.81-93
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• 2014

철원 도피안사 철조비로자나불좌상, 동해 삼화사 철조노사나불좌상, 평택 만기사 철조여래좌상은 통일신라에서 고려시대에 조성된 철불로서 균열, 탈락, 박리박락, 각종 오염물 등이 발생하였다. 방사선 투과촬영을 활용한 철불의 손상도 평가 결과, 철불 내부에서는 균열, 이격, 탈락, 주물공, 보수물질 등이 확인되었다. 그러나 철의 강도로 보아 외부로부터 큰 충격이 가해지지 않는 이상 현재의 상태를 유지할 수 있을 것으로 보인다. 철불의 제작에는 내형과 외형을 철심과 못을 사용하여 고정하였으며, 표면의 이음선과 양각된 명문, 따로 주조되어 결합된 손으로 보아 초중자주조법으로 조성되었을 것으로 판단된다.

• 환경생물
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• 제18권3호
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• pp.307-313
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• 2000

석유화학 공업으로부터 생산되는 방향족 탄화수소 화합물질들은 여러 가지 산업과정에서 널리 활용되고 있으나, 자연계에 오염될 때에는 쉽게 분해되지 않는다는 점에서 환경 오염물질로 주목받고 있다. 방향족 탄화수소 물질의 미생물 분해는 산화반응에 의한 benzene고리의 개환으로부터 시작되기 때문에 이 개환 작용을 갖는 미생물의 분리와 함께 그 분해 기능을 연구하는 것은 매우 중요한 일이다. 본 연구에서는 여천 화학공업단지 폐수로부터 benzoate와 catechol 등의 방향족 탄화수소에 대하여 분해능이 우수한 균주를 분리하여 생화학적 특성과 세포 지방산 분석에 의하여 동정한 결과 Pseudomonas putida로 밝혀졌다. 따라서 이 균주를 Pseudomonas putida Z104라 명명한 후, benzoate와 catechol의 분해과정을 검토하였다. Pseudomonus putida Z104의 catechol분해능에 대하여 환경요소의 영향을 실험한 결과, 3$0^{\circ}C$와 pH 7.0 그리고 0.5mM의 농도에서 왕성한 세포의 생장과 catechol의 분해능을 보였으다. 그러므로 Z104 균주는 benzoate를 연속적으로 완전분해시키는 유전자를 모두 가지고 있다는 점에서 활용가치가 있는 균주라고 판단된다.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2005년도 학술발표논문집
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• pp.241-246
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• 2005

Doam watershed is located at alpine areas in the Kangwon province. The annual average precipitation, including snow accumulation during the winter, at the Doam watershed is significantly higher than other areas. Thus, pollutant laden runoff and sediment discharge from the alpine agricultural fields are causing water quality degradation at the Doam watershed. To estimate soil erosion from the agricultural fields, the Universal Soil Loss Equation (USLE) has been widely used because of its simplicity to use. The USLE rainfall erosivity (R) factor is responsible for impacts of rainfall on soil erosion. Thus, use of constant R factor for the Doam watershed cannot reflect variations in precipitation patterns, consequently soil erosion estimation. In the early spring at the Doam watershed, the stream flow increases because of snow melt, which results in erosion of loosened soil experiencing freezing and thaw during the winter. However, the USLE model cannot consider the impacts on soil erosion of freezing and thaw of the soil. Also, it cannot simulate temporal changes in USLE input parameters. Thus, the Soil and Water Assessment Tool (SWAT) model was investigated for its applicability to estimate soil erosion at the Doam watershed, instead of the widely used USLE model. The SWAT hydrology and erosion/sediment components were validated after calibration of the hydrologic component. The $R^2$ and Nash-Sutcliffe coefficient values are higher enough, thus it was found the SWAT model can be efficiently used to simulate hydrology and sediment yield at the Doam watershed. The effects of snow melt on SWAT estimated stream flow and sediment were investigated using long-term precipitation and temperature data at the Doam watershed. It was found significant amount of flow and sediment in the spring are contributed by melting snow accumulated during the winter. Thus, it is recommend that the SWAT model capable of simulating snow melt and long-term weather data needs to be used in estimating soil erosion at alpine agricultural land instead of the USLE model for successful soil erosion management at the Doam watershed.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2005년도 춘계학술발표대회 개요집
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• pp.387-392
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• 2005

For the production of further functional bio-degradable plastic(polybutylene succinate:PBS) with $TiO_{2}$ as photocatalyst, which shows the decomposition of detrimental organic compound and pollutant under ultraviolet irradiation, we attempted to prepare $TiO_{2}$ coatings on PBS substrate by HVOF and plasma spraying techniques under various conditions. The microstructures of coatings were characterized with SEM and XRD analysis, and the photocatalytic efficiency of coatings was evaluated through the photo degradation of gaseous acetaldehyde. The effects of primary particle size and spraying parameters on the formation behavior, photo catalytic performance and mechanical characteristics of the coatings have been investigated. The results indicated that with respect to both the HVOF sprayed $P_{200}$ and $P_{30}$ coatings, the high anatase ratio off 100% can be achieved regardless of fuel gas pressure. On the other hand, the HVOF sprayed $P_{7}$ coating exhibited largely decreased anatase ratio (from 100% to 49.1%) with increasing the fuel gas pressure, which may be attributed to the much higher susceptibility to heat of 7nm agglomerated powder. In terms of photocatalytic efficiency, HVOF sprayed $P_{200}$ and $P_{30}$ coatings seem to predominate as compared to that of plasma sprayed $P_{200}$ coatings owing to the higher anatase ratio. However, the HVOF sprayed $P_{7}$ coatings didn't show the photo catalytic activity, which may result from the extremely small reaction surface area to the photo-catalytic activity and low anatase ratio. Such functional PBS with new roles is expected to cosiderably contribute to the reduction of aggravated environmel problem.

• Spatial Information Research
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• 제3권1호
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• pp.1-18
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• 1995

호소나 하천들의 오염은 일반적으로 점원 오염과 비점원 오염으로 구분할 수 있다. 연구 대상지역인 충주호주변은 호소 주위 도시들의 하수나 공장폐수에 의한 점원 오염뿐만 아니라, 강우에 의한 토양 침식 등에 의하여 야기되는 비점원 오염이 수년전부터 아주 중요한 오염원으로 등장되고 있다. 본 연구에서는 충주호주변의 이러한 비점원 오염을 GIS를 이용하여 정량적으로 분석하였으며, 대상 환경정보들을 데이타베이스화하여 GIS지도모형연구를 실시하였다. 지표 유출량 분석이 이루어진 후, 토양 유실량 계산과 원격탐사기법을 이용한 호소의 녹조류 분석 등이 실시되었으며, GIS 를 이용하여 구현된 환경지질정보시스템에 의하여 종합 분석되었다. 본 연구는 한국자원연구소 환경지질연구그룹에서 시행하고 있는 환경지질도작성 연구사업의 일부이며, 금번 연구결과를 토대로 차년도의 목표에서는 호소주변 개발에 따른 자연환경 오염 최소화의 개발적지 선정과 호소주변 도시들의 확장, 발달에 의한 호소 환경오염 방지 대책이 연구될 것이다.

• KEPCO Journal on Electric Power and Energy
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• 제1권1호
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• pp.115-120
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• 2015

$K_2CO_3$-based dry regenerable sorbents were prepared by spray-drying techniques to improve mass produced $K_2CO_3-Al_2O_3$ sorbents (KEP-CO2P, hereafter), and then tested for their $CO_2$ sorption capacity by a $2,000Nm^3/h$ (0.5 MWe) $CO_2$ capture pilot plant built for Unit 3 of the Hadong thermal power station in 2010. Each of the sample sorbents contained 35 wt.% $K_2CO_3$ as the active materials with various support materials such as $TiO_2$, MgO, Zeolite 13X, $Al_2O_3$, $SiO_2$ and hydrotalcite (HTC). Their physical properties and reactivity were tested to evaluate their applicability to a fluidized-bed or fast transport-bed $CO_2$ capture process. The $CO_2$ sorption capacity and percentage utilization of $K_2CO_3$-MgO based sorbent, Sorb-KM2, was $8.6g-CO_2/100g$-sorbents and 90%, respectively, along with good mechanical strength for fluidized-bed application. Sorbs-KM2 and KT were almost completely regenerated at $140^{\circ}C$. No degradation of Sorb-KM by $SO_2$ added as a pollutant in flue gas was observed during a cycle test.