• 생명과학회지
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• 제24권8호
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• pp.887-894
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• 2014

유기염소계 난분해성 산업폐수처리에 효과적인 미생물제제 개발을 위하여 PCP (pentachlorophenol)와 TCE (trichloroethylene) 등과 같은 유기계 염소화합물이 오염되어있는 토양 및 산업폐수로부터 PCP 분해활성이 높은 GP5, GP19와 TCE 분해활성이 높은 GA6, GA15를 분리하였다. 이들 분리균주 GP5, GP19, GA6, GA15등은 Acetobactor sp., Pseudomonas sp., Arthrobacer sp., Xanthomonas sp.과 유사한 것으로 나타나 최종적으로 Acetobacter sp. GP5, Pseudomonas sp. GP19, Arthrobacer sp. GA6, Xanthomoas sp. GA15로 명명하였다. 유기염소계 산업폐수의 처리를 위한 복합미생물제제 OC17은 PCP와 TCE를 분해하는 4개의 분리 분리균주와 방향족화합물 분해균주인 Acinetobacter sp. KN11, Neisseria sp. GN13의 배양액을 혼합하여 제조하였다. 복합미생물제제 OC17은 $2.8{\times}10^9CFU/g$의 균체수를 갖고 있으며, 밀도는 $0.299g/cm^3$, 수분함량은 26.8%를 나타내었다. 복합미생물 제제 OC17은 PCP 500 mg/l가 포함되어있는 인공폐수를 이용한 실험에서 배양 65시간에 87%의 분해효율을 나타내었고, TCE (300 uM)의 분해효율은 배양 50시간에 90%의 분해효율을 나타내었다. 복합미생물제제 OC17을 이용한 유기 염소계 산업폐수의 처리효율 시험을 위한 연속배양 실험 에서 10일간 처리 하였을 때 91%의 COD 제거효율을 나타내었다.

• 생태와환경
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• 제39권1호통권115호
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• pp.100-109
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• 2006

본 연구는 영양염이 풍부한 하수처리수를 이용한 인공수로에서 사상성 부착조류의 성장에 미치는 요인들(유속. 부착기질, 인 농도)을 평가하였다. 실험은 하수처리수를 이용한 현장 인공수로와 실내 순환수로에서 부착조류의 성장실험을 수행하였고, 서로 다른 인 농도에서의 사상성 부착조류 종간의 성장률과 인 흡수율을 비교하였다. 조절된 유속조건(5 ${\sim}$ 15 cm $s^{-1}$)에서 사상성 부착조류의 순생산성은 유속이 빠를수록 높았으나 최대의 순생산성은 10 cm $s^{-1}$ 유속에서 나타났다. 현장 인공수로와 실내순환수로 실험 간에 사상성부착조류의 최대성장은 기질에 따라 다르게 나타났다. 부유물질이 충분히 제거되지 않았던 현장 인공수로 실험에서는 망목이 20 mm인 철망에서, 실내순환수로 실험에서 사상성 부착조류의 성장은 자연섬유망에서 높게 나타났다. 0.05 ${\sim}$ l.0 mg P $L^{-1}$로 조절된 인 농도범위에서 3종의 사상성 부착조류 성장률은 인 농도가 높아짐에 따라 증가하였으나, 각 종들은 인 농도에서 따라 차별적인 성장을 나타냈다. 또한 영양염 농도가 매우 높은 환경에서 사상성 부착조류 생물량의 발달이 크면 클수록 높은 유속이 사상체의 탈리를 유발하여 조류의 성장을 감소시키는 제한요인으로 작용할 수 있음이 제시되었다. 탈리된 사상체는 연결된 하천, 저수지, 하류의 수질과 생태계를 악화시킬 수 있기 때문에 하천 수질관리에 있어 중요한 요인으로 고려한 필요성이 크다.

• 한국초전도ㆍ저온공학회논문지
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• 제25권3호
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• pp.7-12
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• 2023

Isolation of pollutant-degrading bacteria is important in bioaugmentation, one of the methods for biological degradation of environmental contaminants. We focused on the magnetic activated sludge (MAS) process as a culture method that efficiently concentrates degrading bacteria, and cultured activated sludge with 1,4-dioxane as a model pollutant. After 860 days of operation, MLVSS, which indicates the amount of sludge, increased from 390 mg/L to 10,000 mg/L, and the removal rate of organic matter including 1,4-dioxane, tetrahydrofuran, and glucose in the artificial wastewater reached up to 97%. Based on these results, the MAS process was successfully used to acclimate activated sludge with 1,4-dioxane. Bacterial flora analysis in the MAS showed that bacteria of the genus Pseudonocardia, already reported as 1,4-dioxane degrading bacteria, play an important role in the degradation of this pollutant. The MAS process is a suitable culture method for acclimation of environmental pollutants, and the findings indicate that it can be used as an enrichment unit for pollutant-degrading bacteria.

• 한국습지학회지
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• 제22권3호
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• pp.178-186
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• 2020

본 연구에서는 낙동강 주요 지류의 기온과 수온 자료를 이용하여 탄성도를 산정하고 수온의 민감도 분석을 수행하였다. 탄성도에 대한 신뢰구간 추정과 가설검증이 가능한 비모수 기반의 탄성도 해석기법을 개발하여 기존 중간값을 이용하는 기법과 비교하고 적용성을 검토하였다. 계절적으로 겨울의 탄성도가 낮고 여름과 가을의 탄성도가 높은 것으로 분석되어 기온의 변동에 따른 수온 및 수질의 변동이 클 것으로 분석되었다. 공간적으로 하수처리장 방류수, 중소 축사의 가축폐수, 소규모 공장의 오·폐수 등 인위적인 요인의 영향을 받는 금호강 지역의 탄성도가 낮은 경향을 나타내고 있다. 낙동강 주요 지류의 탄성도는 약 이상이고 유의수준 5%에서 타당하므로 기후변화에 따른 기온-수온 변동이 큰 것으로 분석되었다.

• 한국물환경학회지
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• 제18권3호
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• pp.245-251
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• 2002

Reactive dyes waste water, a toxic and refractory pollutant, was treated by an electrochemical method using $Ti/IrO_2$ as anode and Stainless Steel 316 as cathode. In this technique, sodium chloride as an electrolyte was added. A number of experiments were run in a batch system. Artificial samples (reactive blue 19, red 195, yellow 145) were used. Operation parameters, such as supporting electrolyte concentration, current density, pH and sample concentration have been investigated for their influences on COD and color removal efficiencies during electrolysis. After 5 and 90 minites of eletrolysis, color was reduced by 51.5% and 98.9% respectively. Under the condition of current density $10A/dm^2$, NaCl concentration 12mg/l and pH 3, 62.9% of $COD_{Cr}$ was removed after electrolysis for 90 minites. The optimum condition of color removal and COD reduction in this work was found to be the following : pH 3, sodium chloride concentration 20g/l, current density $10A/dm^2$. As a result, we confirmed to be effective to color removal and reduction of refractory organic material.

• 환경영향평가
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• 제9권3호
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• pp.163-176
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• 2000

The purpose of this study is to analyze the pollutant loads and its distribution, and to suggest the management of nonpoint sources in Daechong Reservoir. The loads from point and nonpoint sources such as population, industry, livestock and land use were calculated per stream or river with topography(1:25,000) of the watershed of Daechong Reservoir. The generating pollutant loads were obtained through multiplication of pollutant sources by generating pollutant quantity per unit pollutant source. The effluent point sources loads is defined as loads from wastewater treatment facilities such as domestic, industrial and livestock wastewater treatment facilities, which were calculated through multiplication of effluent flowrates by water quality constituents concentration. Untreated point sources loads were estimated to be 35 % of total point sources loads. The effluent nonpoint sources pollutant loads were obtained through the multiplication of generating nonpoint sources loads by effluent ratios based on previous studies. The effluent nonpoint sources loads have the ratio of 26.2% of total BOD effluent loadings, 20.1% of total T-N effluent loadings, and 10.5% of total T-P effluent loadings. For the reduction of nonpoint sources loads in Daechong Reservoir, silviculture, artificial wet land, and grassed waterways could be applied. And untreated livestock waste scattered can result in nonpoint loadings, so required the livestock wastes treatment facilities and purifying facilities together with the management of shed, pasture, livestock waste storage site and composting site. Finally, remote sensing and GIS should be applied to the identification of distribution of water quality, watershed, the location and scale of nonpoint sources, effluent process during rainfall, for more detailed analysis of nonpoint sources.

• 한국물환경학회지
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• 제22권1호
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• pp.116-121
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• 2006

Fundamental investigations have been carried out to find the applicability of manganese nodule as an adsorbent of nickel ion with an intention that nickel can be secured in manganese nodule along with the treatment of wastewater. The average content of manganese in nodules which used in the experiments was about 27%. The content of nickel in manganese nodules was observed to increase up to 4 times higher with comparison to its original value after adsorption. When the initial concentration of nickel ion in artificial wastewater was lower than 500 mg/L, its adsorbed amount on manganese nodule was shown to increase continuously. However, no more than about 82 mg/L of nickel was attained at higher initial nickel ion concentration than 500 mg/L. The adsorption of nickel ion was increased with temperature under experimental conditions and as the size of manganese nodule particles became smaller more nickel ion was adsorbed on adsorbent. Regarding the effect of pH, the adsorption of nickel ion was more hindered as the solution became acidic. Adsorption behavior of nickel ion on manganese nodule was found to follow the Freundlich model well and kinetic analysis showed that the adsorption reaction of nickel ion was second order. Thermodynamic parameters for the nickel ion adsorption were estimated on the basis of thermodynamic equations and they were in good agreement with experimental results.

• 상하수도학회지
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• 제34권1호
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• pp.35-43
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• 2020

Turbidity has various effects on the water quality and ecosystem of a river. High turbidity during floods increases the operation cost of a drinking water supply system. Thus, the management of turbidity is essential for providing safe water to the public. There have been various efforts to estimate turbidity in river systems for proper management and early warning of high turbidity in the water supply process. Advanced data analysis technology using machine learning has been increasingly used in water quality management processes. Artificial neural networks(ANNs) is one of the first algorithms applied, where the overfitting of a model to observed data and vanishing gradient in the backpropagation process limit the wide application of ANNs in practice. In recent years, deep learning, which overcomes the limitations of ANNs, has been applied in water quality management. LSTM(Long-Short Term Memory) is one of novel deep learning algorithms that is widely used in the analysis of time series data. In this study, LSTM is used for the prediction of high turbidity(>30 NTU) in a river from the relationship of turbidity to discharge, which enables early warning of high turbidity in a drinking water supply system. The model showed 0.98, 0.99, 0.98 and 0.99 for precision, recall, F1-score and accuracy respectively, for the prediction of high turbidity in a river with 2 hour frequency data. The sensitivity of the model to the observation intervals of data is also compared with time periods of 2 hour, 8 hour, 1 day and 2 days. The model shows higher precision with shorter observation intervals, which underscores the importance of collecting high frequency data for better management of water resources in the future.

• 공업화학
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• 제17권5호
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• pp.483-489
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• 2006

희토류 화합물인 $La_{2}O_{3}$ 및 $CeO_{2}$ 시약과 이들을 함유하는 희토류 광석을 이용하여 제철 폐수 중의 불소 및 유해 중금속 제거에 대하여 연구하였다. 용액 중 불소에 대한 희토류 원소의 제거 반응기구는 $La^{3+}$ 및 $Ce^{4+}$ 등의 양이온이 불소 이온과 불용성 화합물을 형성하는 것으로 알려져 있다. 기존의 불소 제거에 사용되고 있는 소석회와 비교한 결과 $La_{2}O_{3}$ 및 $CeO_{2}$ 의 불소제거 효율이 높았다. HF 용액에서의 제거 효율은 $CeO_{2}$ 광석 < $CeO_{2}$ 시약 < $Ca(OH)_{2}$ < $La_{2}O_{3}$ 광석 < $La_{2}O_{3}$ 시약의 순서였고, 제철 폐수에서는 $Ca(OH)_{2}$ < $CeO_{2}$ 광석 < $CeO_{2}$ 시약 < $La_{2}O_{3}$ 광석 < $La_{2}O_{3}$ 시약의 순서였다(pH의 영향은 소석회인 경우 pH가 증가할수록 불소제거율이 감소하였다. 세륨화합물과 란탄화합물인 경우는 pH 증가에도 불구하고 불소제거 효율이 증가하는 경향을 보였으나 방류 시 수질조건과 불소제거율을 함께 고려할 때 용액의 적정 pH는 7이 적당하다고 판단된다). 망간제거의 경우, pH 7 이하에서는 소석회가 희토류 화합물보다 우수한 망간제거율을 보였고 pH 10에서는 모든 처리제에 대해서 거의 완벽한 제거특성을 보였다. 총크롬 제거의 경우는 산성 조건에서는 란탄화합물이 가장 높은 불소 제거율을 보였으며 pH 7이상에서는 모든 처리제가 좋은 효율을 보였다.

• 환경영향평가
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• 제16권1호
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• pp.59-68
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• 2007

Urban streams have been severely degraded with wastewater and concrete structure over a prolonged period. The Chonggyecheon Restoration Project recovered a stream in the downtown Seoul with landscaping, plantings and bridges after the cover concrete and elevated asphalt road were removed. The project has been criticized partly because it is not an ecological restoration but rather the development of an urban park with an unnaturally straight flowing stream, artificial building structures, and artificial water pumping from the Han River. Nevertheless, the public have praised the project and almost 100,000 visitors per day come to see the reeds, catfish, and ducks. The stream restoration project is attractive to central and regional government decision makers because it increases the public concern of landscape amenity. Several projects such as Sanjichon and Kaeumjungchon are on going and proposed. These projects have a common and different respect in scope and procedure. The Chonggyecheon project in the process of environmental impact assessment (EIA) and prior environmental review system (PERS) reviewed the environmental impacts before development. Kaeumjungchon in the PERS and Sanjichon without EIA and PERS are reviewed. EIA and PERS systems contribute to checking the ecological sustainability of the restoration projects. A stream restoration project is a very complex task, so an integrated approach from plan to project is needed for ecologically sound restoration. Ecological stream restoration requires 1) an assessment of the entire stream ecosystem 2) establishing an ecologically sound management system of the stream reflecting not only benefits for people but also flora and fauna; 3) developing the site-specific design criteria and construction techniques including habitat restoration, flood plains conservation, and fluvial management; 4) considering the stream watershed in land use plan, EIA, PERS, and strategic environmental assessment (SEA). Additionally the process needs to develop the methodologies to enhance stakeholder's participation during planning, construction, and monitoring.