• 한국물환경학회지
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• 제25권2호
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• pp.221-226
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• 2009

We investigated the most effective cutting interval for underwater nutrient removal through cut off the emergent part of hydrophytes at artificial vegetation island (AVR) which was installed for the purpose of water quality improvement in Lake Paldang. We divided the planting area of Phragmites japonica into three parts according to the cutting intervals. The shoot height and relative growth rate of P. japonica, nutrient contents and biomass of cut off P. japonica were measured at each cutting interval. The amount of nutrients which were removed through cut off at each cutting interval was calculated. P. japonica showed full growth, 80% and 60% of full growth before first cut off at three-months, two-months and one-month cutting interval condition respectively. Three-month cutting interval condition showed the largest biomass of cut off P. japonica and one-month cutting interval condition showed the least. However the cut off P. japonica showed the highest content of nutrients at one-month cutting interval condition and the least at three-month cutting interval condition. The amount of phosphorus and nitrogen removal at two-month cutting off condition is the largest among three cutting interval conditions indicating that cut off the emergent part of P. japonica every two months is the most effective to remove the nutrients from water at AVR in eutrophic lakes.

• 한국물환경학회지
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• 제34권5호
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• pp.462-469
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• 2018

There are differences in method and cycle of flow rate survey depending on purpose of the operating department. To verify and use results of flow data according to the purpose, flow data of the directly measured and tele monitoring system were compared to verify validity. Flow measurement in the Ministry of Environment is aimed at setting up a standard flow of target water quality for water quality management and securing flow data of low and normal water level seasons for water quality evaluation. In this study, correlation analysis result ($R^2$) of same time zone data by direct measurement and tele monitoring system (TMS) at Seombon D point, a unit watershed of Seomjin river, for six years ('10 ~ '15) according to implementation of Total Daily Maximum Load (TDML) was wading 0.716, boating 0.962 and on bridge 0.943, and effectiveness of measurement method was verified by characteristics of flow duration as a season of dry and low-water; normal and high water are appropriate for wading, boating, and on bridge respectively. Results revealed it is reasonable to use directly measured results using the wading and boating method for low water level and dry seasons, and TMS data for rainy seasons. It can be used important data for future policy decisions.

• 한국물환경학회지
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• 제26권5호
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• pp.781-788
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• 2010

A pilot study was performed to examine the feasibility of multiple stage of constructed wetland (CW) for nutrient removal. The system is composed of six wetland cells connected with water-ways. The hydraulic of wetland cells is designed as free water surface flow. The treatment capacity was $25m^3d^{-1}$ at HRT of about one day for each cell. The magnitude of nutrient removal was related with the length of wetlands and plant density. Total N and P removal rates were 1353 and $246mg\;m^{-2}d^{-1}$ respectively. The pilot-scale reactor was model as continuous flow system containing contribution of CSTR and PFR typed-reactors. The $k-C^*$ model equation was applied to predict N and P reduction. The result indicated the equation was well guided to estimate reduction of $NO_3-N$ and $PO_4-P$.

• 한국물환경학회지
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• 제27권3호
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• pp.264-272
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• 2011

The objective of this study was to develop a model for predicting long-term runoff in a basin using the ensemble streamflow prediction (ESP) technique and review its reliability. To achieve the objective, this study improved not only the ESP technique based on the ensemble scenario analysis of historical rainfall data but also conventional ESP techniques used in conjunction with qualitative climate forecasting information, and analyzed and assessed their improvement effects. The model was applied to the Geum River basin. To undertake runoff forecasting, this study tried three cases (case 1: Climate Outlook + ESP, case 2: ESP probability through monthly measured discharge, case 3: Season ESP probability of case 2) according to techniques used to calculate ESP probabilities. As a result, the mean absolute error of runoff forecasts for case 1 proposed by this study was calculated as 295.8 MCM. This suggests that case 1 showed higher reliability in runoff forecasting than case 2 (324 MCM) and case 3 (473.1 MCM). In a discrepancy-ratio accuracy analysis, the Climate Outlook + ESP technique displayed 50.0%. This suggests that runoff forecasting using the Climate Outlook +ESP technique with the lowest absolute error was more reliable than other two cases.

• 한국물환경학회지
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• 제20권3호
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• pp.236-240
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• 2004

Autohydrogenotrophic denitrification of high nitrate concentration contaminated wastewater in a batch-scale biofilm reactor has been investigated. High nitrate concentration decreased as pH increased from 7.01 to 9.45. The high nitrate concentrations continuously decrease from $150mg.l^{-1}$ to $0mg.l^{-1}$. Nitrite concentrations increase at about two-thirds way through the denitrification process and thereafter it decreases with time. Autohydrogenotrophic denitrification of high nitrate concentration is passible to use drinking water as well as wastewater, and to deal with wastewater treatment by hetrotrophic denitrification.

• Environmental Engineering Research
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• 제22권1호
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• pp.125-130
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• 2017

The Korean Ministry of Environment and Daegu Metropolitan City are establishing the Korea Water Cluster, which will focus on promoting and escalating Korean water industries. The water industry, a future-oriented and promising business sector, is continuously growing each year worldwide, so the project is very timely. In reality, however, challenges still need to be addressed, such as accessibility, logistics systems, social infrastructures, and attracting good companies. For the Korea Water Cluster to be successful, those issues should be solved, but it is difficult to untangle the matters only with efforts of the Korean Ministry of Environment and Daegu Metropolitan City since some issues will require a great deal of both money and time. Therefore, it is important for the Korean federal government to administer support and finances for certain parts of the project, and for the Korean Ministry of Environment and Daegu Metropolitan City to take on other issues to ensure the Korea Water Cluster is successful long-term. The success of the Korea Water Cluster project will result in the Korea Water Cluster becoming a global hub for the future water industries.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2005년도 학술발표회(2)
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• pp.1226-1227
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• 2005

• 한국물환경학회지
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• 제37권2호
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• pp.114-127
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• 2021

Water pollution in the lower reaches of the Namhan River is getting worse due to drought and a decrease in water quantity due to climatic changes and hence is affecting the water quality of Paldang Lake. Accordingly, we have used a water quality index (WQI) and statistical analysis in this study to identify the characteristics of the water quality in the lower reaches of the Namhan River, the main causes of water pollution, and tributaries that need priority management. Typically, 10 items (WT, pH, EC, DO, BOD, COD, SS, T-N, T-P, and TOC) were used as the water quality factors for the statistical analysis, and the matrix of data was set as 324 × 10·1. The correlation analysis demonstrated a strong correlation between Chemical Oxygen Demand (COD) and T-P with a high statistical significance (r=0.700, p<0.01). Furthermore, the result of principal component analysis (PCA) revealed that the main factors affecting the change in water quality were T-P and organic substances introduced into the water by rainfall. Based on the Mann-Kendall test, a statistically significant increase in pH was observed in SH-1, DL, SH-2, CM, and BH, along with an increase in WQI in SH-2 and SM. BH was identified as a tributary that needs priority management in the lower reaches of the Namhan River, with a "Somewhat poor" (IV) grade in T-P, "Fair" grade in WQI, and "Marginal" grade in summer.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2005년도 학술발표회(2)
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• pp.1209-1210
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• 2005

• 한국막학회:학술대회논문집
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• 한국막학회 2005년도 춘계 총회 및 학술발표회
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• pp.153-156
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• 2005