• 한국물환경학회지
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• 제23권2호
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• pp.260-265
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• 2007

This study was carried out to complement water quality standards and to establish new concept for water quality standards reflecting current state of water quality in small streams. By this purpose, discriminant analysis was performed and Water Quality Level Model (WQLM) was developed using the data such as EC, BOD, $COD_{Mn}$, SS, T-N, T-P, $NH_3-N$ in 224 agricultural streams. To give water quality level for water quality parameters, it divided into 20% respectively in the order of excellent water quality. On the basis of the lowest water quality level, water quality level of small streams is granted. As a result of it, number of stream corresponding to Level I was no, Level II was 2 streams, Level III was 22 streams, Level IV was 70 streams, and Level V was 130 streams. Average of water quality in each level was the highest in Level V. EC, SS, and T-N of 7 parameters were selected in variance concerned water quality level. By standardized canonical discriminant function coefficient, EC of three variances was the highest in 0.625 at the discriminant power. The next was T-N (0.509), SS (0.414). By discriminant function for water quality level, Level II was equal to $-2.973+19.376{\times}(EC)+0.647{\times}(T-N)+0.009{\times}(SS)$, Level III was equal to $-3.288+19.190{\times}(EC)+0.733{\times}(T-N)+0.041{\times}(SS)$, Level IV was equal to $-4.462+27.097{\times}(EC)+0.792{\times}(T-N)+0.053{\times}(SS)$, and Level V was equal to $-9.117+40.040{\times}(EC)+1.305{\times}(T-N)+0.111{\times}(SS)$. As a result of test at real agricultural watershed of Jeongan and Euidang in Gongju city, the fitness of WQLM was high to 88.78%. But, to get accomplished water quality assessment more exactly in agricultural streams, we had to concentrate and get vast data, and WQLM was modified and complemented continually.

• 한국환경생물학회:학술대회논문집
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• 한국환경생물학회 2004년도 학술대회
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• pp.25-25
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• 2004

We studied algal growth-related water quality of the Dongbok lake which is the drinking water reservoir for the Gwangju municipality. Peridinium cinctum and several diatomic algal species frequently caused water bloom throughout the lake from early spring to late autumn. With the heaviest predominance of Peridinium cintum in May 2003, COD was 13.7 mg/I in the surface layer. Highly turbid surface water with 46.8 mg/I of SS was also caused by Perdinium bloom. Peridinium bloom decisively eliminated cyanobacterial growth in the lake, otherwise cyanobacterial bloom resulted. Dense algal layer was confined in the upper several meters of the water column above the thermocline, which gives relatively algae-free water in deeper layer suitable for drinking source water supply. Upon collapse of thermocline, water quality of the surface layer was improved while deeper layer was deteriorated in terms of water quality. This paper deals with some details of water quality changes with algal growth in the Dongbok lake past two years.

• 한국물환경학회지
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• 제38권6호
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• pp.275-281
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• 2022

To maintain water quality after water treatment, monitoring whether the quality of treated tap water quality changes is essential. However, current investigations are insufficient to prevent secondary contamination in drinking water supply systems. This study investigated Gyeonggi's e apartment where a red water problem occurred and monitored the water quality and corrosiveness of the overall water supply system to the apartment from June 2021 to April 2022. In a comparison of drinking water quality after water treatment and the influent of the reservoir, turbidity and heavy metal concentrations were increased and residual chlorine was decreased due to increases in temperature. Correlation analysis and principal component analysis (PCA) indicated that a low level of residual chlorine may cause the abscission of Mn²⁺ and Fe²⁺ through microorganism activation, which also causes a high level of turbidity. The corrosion index (LI) in the influent of the reservoir tank was increased due to Ca²⁺ and temperature. These results indicate that the corrosiveness of drinking water and the deterioration of drinking water quality were mainly increased between the drinking water treatment plant and the reservoir tank's influent. The findings provide clear evidence that it is essential to manage water supply systems and reservoir tanks to prevent the secondary contamination of drinking water.

• Environmental Analysis Health and Toxicology
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• 제6권3_4호
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• pp.155-161
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• 1991

The water quality in Wonju stream, Seom river in Kangwon province and Bokha, Shindun stream in Kyeonggi province was investigated between the season of irrigation on July, 1990 and of non-irrigation on September in 1989. The results of water quality obtained from this study were as follows; As for water quality of the Wonju stream and the Seom river, the concentration of COD, T-N, SS and Cu, and for the Bokha, Shindun stream, the concentration of T-N, SS and Cu were exceeded standard levels of quality guideline of agricultural water use in the season of irrigation. However, in the water quality of Wonju and Bokha stream, the concentration of T-N , SS and Cu, and in the Seom river, the concentration of T-N, SS, Cu and Zn were exceeded standard levels of agricultural water quality in the season of non-irrigation. And the average water quality of the 4 streams were not suitable for agricultural water use. The comparison of the annual average water quality of the 4 streams for pH, DO, T-N and SS were in statistics significantly different with p values less than 0.01. When the average water quality between the season of irrigation and non-irrigation in each stream was compared, DO and COD in the Wonju stream, COD in the Seom river, pH, DO, T-N, SS and Cu in the Shindun stream showed a significant difference with p<0.01. The average in the sediment were; COD, 5.65∼26.53 ppm; Cu, 0.26∼0.49 ppm and Zn 0.95∼2.97 ppm. The concentration of three contaminants were markedly higher than the water quality. And the concentration of COD, Zn in the sediment showed a significant difference with p<0.01, and Cu showed a considerably significant difference with p<0.05.

• 한국물환경학회지
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• 제34권2호
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• pp.202-209
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• 2018

The purpose of this study was to analyze the correlation between the effluent of a sewage treatment plant (STP) and the adjacent stream located downstream of the STP in Nakdong River. Flow and water quality data, such as BOD, COD, SS, T-N, and T-P data, for 12 STPs and adjacent downstream monitoring stations in the main stream and tributaries of Nakdong River were collected from 2012 to 2015. As a result of correlation analysis between river flow and water quality at the river water quality measurement point, COD, SS, and T-P were correlated positively with the river flow rate at 6, 8, and 6 points, respectively. As a result of analyzing the water quality of sewage treatment plant effluents and downstream streams, BOD and COD were correlated at 2 and 3 points, respectively. T-N showed a positive correlation at 9 points, and 7 of them had a strong positive correlation, indicating that sewage treatment effluent had a large effect on downstream streams. In this study, we found that the correlation between the river flow rate and the water quality factors (COD, SS, TP) was high at river water measurement points, and the sewage treatment plant effluent was correlated with the T-N value of adjacent streams.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2018년도 학술발표회
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• pp.493-493
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• 2018

The purpose of this study was to analyze the correlation between the effluent of the sewage treatment plant (STP) and the adjacent stream located downstream of the STP in Nakdong River. The flow and water quality such as BOD, COD, SS, T-N, and T-P data for 12 STPs and adjacent downstream monitoring stations in the main stream and tributaries of Nakdong River were collected from 2012 to 2015. As a result of correlation analysis between river flow and water quality at the river water quality measurement point, COD, SS and T-P were correlated positively with river flow rate at 6, 8, and 6 points, respectively. As a result of analyzing the water quality of sewage treatment plant effluent and downstream stream, BOD and COD were correlated at 2 and 3 points, respectively. T-N showed a positive correlation at 9 points, and 7 of them had a strong positive correlation, indicating that sewage treatment effluent had a large effect on downstream streams. In this study, we found that the correlation between river flow rate and water quality factors (COD, SS, TP) was high for river water measurement points, and the sewage treatment plant effluent was correlated with the T-N value of adjacent streams.

• 한국측량학회지
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• 제16권2호
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• pp.225-233
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• 1998

수질오염 현상을 규명하기 위해서는 지속적으로 호수의 수질을 조사할 필요가 있는데 이것은 시간과 경비가 많이 소요될 뿐만 아니라 광범위한 지역을 조사하기가 상당히 어렵다. 그러나 인공위성에 의한 원격탐사 기법은 동시에 넓은 지역에 걸쳐 수질상태를 측정할 수 있고 또한 주기적으로 동일 지점을 측정할 수 있기 때문에 수질을 조사하는데 효과가 크다. 또한 Landsat의 센서들 중에는 파장별로 물체를 감지하는 특성이 있어서 수질의 분포를 단시간내에 비교적 정확하게 확인해 낼 수 있으며 그 영상을 Color로 표현하는 것이 가능하다. 따라서 본 연구는 인공위성 자료를 이용하여 투명도, 수심, 표층수온 등 수질인자 추출을 시도하고 그에 따른 수질인자 실험식을 제시하여 화진포호의 수질분포 영상도를 작성하였다. Landsat TM 영상의 DN으로부터 수질인자를 추출하고 이것을 다시 GIS를 이용하여 TIN분석을 한 후 수질분포 영상도를 작성하면 실제 관측하여 얻어진 값을 이용하여 나타낸 것 보다 광범위한 지역에 대하여 비교적 정확한 패턴임을 알 수 있다.

• 상하수도학회지
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• 제20권4호
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• pp.585-594
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• 2006

This study focused on the causes of fish kills and its prevention methods in Yudeung Stream, Daejeon, Korea. Intense field data, continuous water quality monitoring system and water quality modeling were applied to analyze the causes. Pollutant can be delivered to urban streams by surface runoff and combined sewer overflows in rainfall events. However, water quality analysis and water quality modeling results indicate that the abrupt fish kills in the Yudeung stream seems to be caused by combined effect of DO depletion, increase in turbidity and other toxic material. Excessive fish population in the study area may harm the aesthetic value of the stream and also has greater potential for massive fish kills. It is suggested to implement methods to reduce delivery of pollutants to the stream not only to prevent fish kills but also to keep balance of ecosystem including human uses. Frequent clean up of the urban surface and CSO, installation of detention basin will be helpful. In the long run, it seems combined sewer system has be replaced with separate sewer system for more effective pollutant removal in the urban area.

• 한국물환경학회지
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• 제30권4호
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• pp.429-440
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• 2014

This study was conducted to investigate the main cause of water quality deterioration during the spring season in the transition zone between the South Han River and the river-reservoir Paldang. A water quality model modified from QUAL2E (U.S.EPA) was used, and the model showed that eutrophication and algal production in the low flow season affected about 60% of the organic pollution at the downstream of the South Han River. This result means that phosphorus control is prior to external organic material management to ameliorate the deterioration of water quality in the water body.

• 한국물환경학회지
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• 제29권4호
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• pp.514-522
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• 2013

The major 24 tributaries in Nam-River mid-watershed were monitored for discharge and water quality in order to understand the characteristics of the watershed and to select the tributary catchment for improving water quality. According to the analytical results of discharge and water quality monitoring data of 24 tributaries, the mean value of discharge below $0.1m^3/s$ was 62.5% among the monitored tributaries and it mostly exceeded the water quality standards of Nam-river mid-watershed ($BOD_5$ = 3 mg/L, T-P = 0.1 mg/L over). According to the stream grouping method and the water quality delivery load density ($kg/day/km^2$) based on the results of tributary discharge and water quality monitoring, the tributary watersheds for improving the water quality were selected. In the Nam-River mid-watershed, tributaries in the GaJwaCheon, HaChonCheon catchment (Group D, $BOD_5$ = 3 mg/L over) and in the UirYeongCheon, SeokGyoCheon catchment (Group A, T-P = 0.1 mg/L over), which have a small flow (and/or large flow) and a high concentrations of water pollutants. The various water quality improving scheme for tributaries, in accordance with the reduction of potential point source pollution by living sewage and livestock wastewater, should be established and implemented.