• 한국물환경학회지
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• 제34권5호
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• pp.487-493
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• 2018

Urban stormwater runoff is the one of the most extensive causes of deterioration of water quality in streams in urban areas. Especially, in the Suyeong River watershed, non-point sources from urban-residential areas are the most common cause of water pollution. Also, it has been ascertained that BOD and COD as indexes of organic matter, have limitation on management of Suyeong River's water quality. In this study, changes of organic matter properties of Suyeong River from inflow of non-point source during rainfall were investigated. Fractions of organic matters were analyzed using water samples collected at two sites (Suyeong River and Oncheon Stream) during a rain event. Variations of dissolved organic carbon (DOC) concentration by rainfall were similar to flow rate change in the river. Distribution of organic matter fraction according to change of rain duration revealed that while hydrophilic component increased at initial rainfall, the hydrophobic component was similar to change in dissolved organic carbon (DOC) concentration. Also, the relative proportion of hydrophilic components in organic matter in river water increased, due to rainfall. Results of biodegradation of organic matters revealed that decomposition rate of organic matters during rainfall was higher than that of during a non-rainfall event.

• 한국물환경학회지
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• 제26권2호
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• pp.268-278
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• 2010

This study derived the effectiveness analysis results of construction of wastewater treatment plant under climate change scenarios. Canadian Global Coupled Model (CGCM3) was used and A1B and A2 of Special Report on Emission Scenario (SRES) were selected. Regional climate change data for this application were downscaled by using Statistical Downscaling Model (SDSM) and the flow and BOD concentration durations were obtained by using Hydrological Simulation Program - Fortran (HSPF). The criteria for low flow and water quality were chosen as $Q_{99}$, $Q_{95}$, $Q_{90}$ and $C_{30}$, $C_{10}$, $C_1$. The numbers of days to satisfy the instreamflow requirements and target BOD concentration were also added to the criteria for comparison. As a results, small wastewater treatment plant improved the water cycle due to the increase of low flow and the decrease of BOD concentration. But climate change affected the reduction of effectiveness significantly. Especially in case of construction of small waste water treatment plant in the upstream region, it is necessary to take climate change impact into consideration since it is usually related to the low flow and the water quality of the stream.

• 한국농공학회논문집
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• 제60권6호
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• pp.83-96
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• 2018

The objective of this study was to estimate the climate change impact on water quantity and quality to Saemanguem watershed using SWAT (Soil and water assessment tool) model. The SWAT model was calibrated and validated using observed data from 2008 to 2017 for the study watershed. The $R^2$ (Determination coefficient), RMSE (Root mean square error), and NSE (Nash-sutcliffe efficiency coefficient) were used to evaluate the model performance. RCP scenario data were produced from 10 GCM (General circulation model) and all relevant grid data including the major observation points (Gusan, Jeonju, Buan, Jeongeup) were extracted. The systematic error evaluation of the GCM model outputs was performed as well. They showed various variations based on analysis of future climate change effects. In future periods, the MIROC5 model showed the maximum values and the CMCC-CM model presented the minimum values in the climate data. Increasing rainfall amount was from 180mm to 250mm and increasing temperature value ranged from 1.7 to $5.9^{\circ}C$, respectively, compared with the baseline (2006~2017) in 10 GCM model outputs. The future 2030s and 2070s runoff showed increasing rate of 16~29% under future climate data. The future rate of change for T-N (Total nitrogen) and T-P (Total phosphorus) loads presented from -26 to +0.13% and from +5 to 47%, respectively. The hydrologic cycle and water quality from the Saemanguem headwater were very sensitive to projected climate change scenarios so that GCM model should be carefully selected for the purpose of use and the tendency analysis of GCM model are needed if necessary.

• Journal of Dairy Science and Biotechnology
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• 제19권1호
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• pp.13-21
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• 2001

Milk can be regarded as a complete food, containing protein, fat, lactose, vitamins and minerals. Milk is heated for a variety of reasons. The main reasons are: to remove pathogenic organisms; to increase shelf-life. But, when milk is heated, many changes take place: denaturation of whey proteins and interaction with casein, Maillard browning, losses of vitamin and minerals. The addition of a additive and milk powder to flavor and taste may cause undesirable change of quality during heating milk. The reconstituted milk is the milk product resulting from the addition of water to the dried or condensed form in the amount necessary to re-establish the specified water solids ratio. Therefore, according to the increasement of consumption of processed milk, the necessity for study about the quality of processed milk mixed with reconstituted milk arose.

• 에너지공학
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• 제26권1호
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• pp.68-75
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• 2017

Global warming affects water supply and water resources throughout the world. In many countries, climate change affects significantly on the fresh water resources. Vietnam is exposed mainly, to landslides and floods triggered by tropical storms and monsoon rains, although storm surge, whirlwind, river bank and coastal line erosion, hail rain. In addition to the prevalent drought, there are many major water challenges, including water availability, stress, scarcity and accessibility, because of poor resource management. Fast growth of urbanization, industrialization and population growth, agricultural activities and climate change cause heavy pressure on water quality. Both domestic and industrial wastewater, as well as storm water shares the same drainage. The common facilities for wastewater treatment are not available. Therefore, wastewater is treated only superficially and then discharged directly into rivers and lakes causing serious pollution of surface water environment. In this paper, we reported the severe water crisis and massive green algal blooms formation in Vietnam rivers and lakes. This is the biggest evidence of climate change variations in Vietnam.

• 대한환경공학회지
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• 제30권5호
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• pp.567-573
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• 2008

달천의 하도내에서 종횡단의 수질조사 및 하천특성에 대한 분석을 수행하였으며, 주요 지점을 중심으로 유량변화에 따른 수질변화를 검토하였다. 강우의 발생으로 유량이 증가한 경우에 BOD의 농도는 감소하였으며, TN과 TP의 농도는 증가한 것으로 나타났다. 유량이 증가하였던 Case 2에서 BOD, TN, TP는 모두 유속과 수심에 대하여 큰 상관계수를 보였다. 강우가 비점오염원의 유입을 유도하여 하도내 수질변화에 많은 영향을 미치고 있는 것으로 분석되었다. 하도내의 유속은 수치모형(SMS)을 통해서 분석할 수 있었으며, 경사가 크고, 하도의 폭이 좁은 상류 구간에서 비교적 유속이 큰 것으로 나타났다. 2차원 하도내에서 오염원의 거동특성이 모의되었으며, 주수로인 흐름의 중앙부분으로 오염원이 빠르게 확산되는 것으로 나타났다. 오염 확산은 흐름에 큰 영향을 받고 있는 것으로 모의되었다.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• 제3권1호
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• pp.33-39
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• 1999

A two-dimensional numerical experiment and field observations were conducted to evaluate changes in sea water movement and the water quality environment related to comprehensive projects of waterfront development around Kwangyang Bay on the south coast of Korea. Tidal flow velocities, especially in the western part of the bay, were considerably slower as a result of the development projects. Accordingly, the seawater exchange ratio reduced from 38.7% to 26.3%. The impact of dredging work on the water quality environment was much stronger than expected. Furthermore, after the completion of the industrial parks and container-exclusive wharfs, COD from the waste water treatment plant will be dispersed extensively into the adjacent water at a level of less than 0.1 mg/l for up to 142.5 $\textrm{km}^2$. Therefore, consistent monitoring and management of the water quality environment is strongly recommended.

• 한국환경과학회지
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• 제6권3호
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• pp.239-247
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• 1997

The numerical experiments using a particle tracking model have been performed for predicting the change of water Quality and shoreline. In present study, comparison of the numerical model results with the analytic solution shows that the point of the mainmum concentration and the distribution pattern is very similar. The reflection effect from the boundary was newly Introduced for making clear the effect of the closed boundary which set limits to application of a particle tracking model. The present model seems to reappear physical phenomenon well. This model shows well qualitative appearance of pollutant diffusion in Kwangan beach. Therefore, this model is regarded as a useful means for predicting diffusion movement of suspended sand, and change of water quality.

• 해양환경안전학회지
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• 제2권1호
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• pp.89-95
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• 1996

This paper describes a fuzzy controlled pre-chlorination technique for purifying the pulluted raw water in water purification lants. For the purpose of obtaining the high quality water, the appropriate pre-chlorine dosage rate has to be continuously adjusted according to a change in quality of a intake raw water, weather, solar nergy mount, temperature and etc. Therefore, the method of expressing an expert's empirical knowledge cumulated from his past carrier by fuzzy reasoning and the fuzzy controller design technique is necessary.In this paper fuzzy membership functions and rules accordingto emprircal knowledge and experimental field data were obtained, And also fuzzy cintriller design using four feedforward components for the determination of pre-chlorine dosage rate and four feedback ones for the compensation of its dosage rate with residual chlorine and its change rate, was executed.

• Journal of Plant Biology
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• 제11권4호
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• pp.1-8
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• 1968

The persent paper discusses the relation between water pollution and aquatic organisms resulted from the study of the water quality and the kinds of algea and aquatic insects both of the An-yang River from Mt. Kwan-ak to the Han River and of the Kock-neung River from Mt. Puk-han to the Han River during the spring of 1965 and 1966. According to the change of water quality, the An-yang River might be divided into three areas. In the first area, from Mt. Kwan-ak to near An-yang town, water quality is not so polluted that may aquatic organisms such as Anisogamarus ryotoensis, Epeorus, Cambaroides, Zygnem, Batrachospermum moniliform, Draparnaldia glomerata are found. In the second area where water is polluted by the inflow of sewerage water from An-yang town, the concentration of chloride, COD, ammonia-N, nitrate-N, alkali degree increased. Therefore, few aquatic insects and algea are found. In the third area, it is much polluted by the industrial sewerage water frojm Yeong-dong-po; and so the aquatic organisms that indicate strong pollution such as Oscillatoria, Euglena, Tubifex are found in this area. It is also significant that the Nereis japonica that indicates the pollution of brackish water is discorved in the some area. In the case of the Kock-neung River, however, it is not clearly divided into areas, as in the case of the An-yang Riber, according to the pollution of water; but because of villages and towns along the river the gradual pollution of water; but because of villages and towns along the river the gradual pollution of water is observed and accordingly, a considerable change in aquatic organisms is also found in this river. In the area near II-yeung town, for instance, the concentration of the chloride, hardness, nitrite, nitrate is very low, and ammonia-N is not detected; and accordingly the aquatic insects that generally inhabit in mountain stream, such as Anisogamarus ryotoensis, Cambaroides, Epeorus, Thraubs, Hydropsyche are found here. In the down stream of the river, from Kock-chon, the quality of water is considerably polluted and fine sands are found laid on the bottom of the stream; therefore, the aquatic insects are very few, but the algea such as Navicula, Pleusigma, Oscillatoria that indicate water pollution are found in this area.