• Journal of Korean Society of Water and Wastewater
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• v.11 no.2
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• pp.40-49
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• 1997

From water management point of view, the industrialization that we have achieved in the last decades brought out two major changes: water shortage and water quality deterioration. They are getting the big obstacles we must overcome to continuously pursue industrialization for further development in the next century. Many plans using dams and advanced treatment methods have been developed for control of quantity and quality, respectively. In this paper, an alternative is conceptually reviewed which is much different from the plans in regard that the alternative looks at system itself. It is based on an interceptor system coupling with a concept of zero-discharge. This system allows no discharge of wastewaters from point-sources to waterbodies which are very sensitive in terms of water quality. In addition reuse of treated effluents is emphasized to a maximum extent. The application of the system to the Nak-Dong river basin indicated that an interceptor system will need from the middle reaches of the basin where industrialization gets heavier. Since wastewaters are not directly discharged to the river, water quality of the down stream will improve. Treated effluents will be able to be reused at a number of industrial complex which currently get water from the Nak-Dong river. This reuse will help alleviate water shortage. The biggest problem anticipated is cost for building and operating such system. A cost-sharing plan among the beneficiaries is considered. Further research is suggested focusing on detailed engineering and technical matters for potential implementation.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.13 no.2
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• pp.295-305
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• 1993

The purpose of this study is to investigate the theoretical methodology for development of an water quality management system with the optimal control of dilution water and point sources in streams. For the development of objective function and constraints, the control vectors are defined with stream inflows and concentrations of effluents at water treatment plant, and the state vectors are defined with water quality parameters such as DO, $BOD_5$, COD and SS concentrations. The applied system solution technique is augmented Lagrangian technique. The developed water quality optimal management methodology was applied to a case study at the Musim stream in Cheong-ju city. The results of the application show that the methodology is suitable for the comprehensive analysis of polluted water systems, and will be utilized to more useful operation of limited water resources in Korean streams.

• Journal of the Korean Society for Marine Environment & Energy
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• v.9 no.4
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• pp.187-192
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• 2006

In order to know the biological effect of effluent from shipyard and the adjacent stream water on four organisms (flatfish, rockfish, sea squirt and arkshell) cultured around the shipyard, lethal rate and DNA damage were measured after 48 hr exposure and carried out by a single cell gel electrophoresis, namely comet assay. $LC_{50}$ (48 hr) could not be calculated in any organism 48 hours after exposure to effluent from shipyard and stream water, because all organism showed a lethal rate lower than 20%. Regardless of no acute toxicity, DNA damage of flatfish and rockfish was detected higher in Jang-Pyoung stream than in control, whereas sea squirt revealed higher DNA damage in laundry waste water. From these results, Jang-Pyoung stream seemed to have a relatively higher genotoxicity rather than effluent from shipyard.

• Korean Journal of Ecology and Environment
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• v.42 no.4
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• pp.422-431
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• 2009

This study was to provide basic data for aquatic ecosystem research using fishes. Field sampling was carried out at five selected sites of Gap Stream, and fish samples, especially for a selection of sentinel species were collected three times in June, September, and October 2007. We analyzed total length distribution of Zacco platypus in relation with the season and the sampling sites, and then compared with total body weight, condition factor (K), and age distribution of the fish. The fish population data were compared with physico-chemical water quality, obtained from the Ministry of Environment, Korea. Water quality analysis showed a significant nutrient enrichment, based on total nitrogen (TN) and total phosphorus (TP), and organic matter pollution, based on biological oxygen demand (BOD) and chemical oxygen demand (COD) in the Site 5, which is directly influenced by wastewater disposal plant (WDP). Population analysis of the sentinel species showed that the total number of individuals, age distribution, and the population size-structure were influenced by the effluents from the WDP, and that reproductive failure of young-age population were evident in Site 5. According to the relation analysis of total weight to K, the disturbed population was mainly attributed to combined effects of habitat modifications and chemical degradations. Regression analysis of K values against water quality parameters showed significant (p<0.05) positive relations with nutrient and organic matter contents. Our data suggest that the population structure using a sentinel fish species reflected the ambient water quality in the stream and that diagnosis of aquatic ecosystem health using Z. platypus population may be practical for water resource and ecosystem conservations.

• Journal of Korean Society on Water Environment
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• v.38 no.3
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• pp.133-142
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• 2022

Natural organic matter (NOM) is a heterogeneous mixture of organic matter with various polarities and molecular weights in an aquatic environment. This study investigated the effects of separation conditions (resin volume, organic matter, etc.) and the repeated use of the resin for the fractionation of organic components in the DAX resin fractionation method. The distribution characteristics of the organic components ((hydrophilic [Hi], hydrophobic acid [HoA], and hydrophobic neutral [HoN]) under the derived fractionation conditions were also analyzed. Constant fractionation results (i.e. HoA/Hi ratio) were obtained in the column capacity factor (i.e. the packed resin volume) in the range of 50 to 100. The resin-packed column maintained constant separation efficiency for up to two repeated uses. The above conditions were applied to wastewater and stream water samples (before and after rainfall). The results showed that the concentration of organic matter in the wastewater effluent was 2-15 times lower with an increased ratio of hydrophilicity to hydrophobicity (i.e. Ho/Hi) compared to the influent depending on the industrial wastewater classification. Particularly, HoN was found to have a high content distribution, 10.2-50.4% of the total dissolved organic matter (DOM), in the effluents. For the stream water, the content of Hi or HoN increased significantly after rainfall, suggesting a correlation with the distribution characteristics of pollutants from the stream watershed. The results provide useful data to enhance the reliability of the DAX resin fractionation and its application to environmental samples.

• Journal of Korean Society on Water Environment
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• v.34 no.2
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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.

• Korean Journal of Ecology and Environment
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• v.50 no.2
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• pp.238-253
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• 2017

The sewage and wastewater (SAW) are a well-known major source of eutrophication and greentide in freshwaters and also a potential source of thermal pollution; however, there were few approaches to thermal effluent of SAW in Korea. This study was performed to understand the behavioral dynamics of the thermal effluents and their effects on the water quality of the connected streams during winter season, considering domestic sewage, industrial wastewater and hot spring wastewater from December 2015 to February 2016. Sampling stations were selected the upstream, the outlet of SAW, and the downstream in each connected stream, and the water temperature change was monitored toward the downstream from the discharging point of SAW. The temperature effect and its range of SAW on the stream were dependent not only on the effluent temperature and quantity but also on the local air temperature, water temperature and stream discharge. The SAW effects on the stream water temperature were observed with temperature increase by $2.1{\sim}5.8^{\circ}C$ in the range of 1.0 to 5.5 km downstream. Temperature effect was the greatest in the hot spring wastewater despite of small amount of effluent. The SAW was not only related to temperature but also to the increase of organic matter and nutrients in the connected stream. The industrial wastewater effluent was discharged with high concentration of nitrogen, while the hot spring wastewater was high in both phosphorus and nitrogen. The difference between these cases was due to with and without chemical T-P treatment in the industrial and the hot spring wastewater, respectively. The chlorophyll-a content of the attached algae was high at the outlet of SAW and the downstream reach, mostly in eutrophic level. These ecological results were presumably due to the high water temperature and phosphorus concentration in the stream brought by the thermal effluents of SAW. These results suggest that high temperature of the SAW needs to be emphasized when evaluating its effects on the stream water quality (water temperature, fertility) through a systematized spatial and temporal investigation.

• Journal of Environmental Science International
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• v.23 no.3
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• pp.433-445
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• 2014

The objective of study was to analyze seasonal and inter-annual patterns of water chemistry of Miho Stream watershed during 2004 - 2007 along with some influences of tributaries and summer monsoon on the stream water quality. For the study, eight physico-chemical parameters such as nitrogen, phosphorus, BOD, COD and chlorophyll-a (CHL) etc. were analyzed in relation to spatial and temporal variability of seven sampling sites of the mainstream and some tributaries in the watershed. In the upstream reach, Mean of BOD, COD and TP averaged 3.2 mg/L, 6.5 mg/L and $186{\mu}g/L$, respectively, indicating an eutrophic conditions as a III-rank in the stream water quality criteria from the Ministry of Environment, Korea(MEK). The eutrophic water was due to a combined effect of Chiljang tributary with high nutrients ($TP=844{\mu}g/L$, TN=8.087 mg/L) and the point sources from some wastewater treatment plants. In the meantime, BOD, TN, and TP in the downstream reach were about > 1.2-1.5 folds than the values of the midstream reaches. This was mainly attributed to effluents of nutrient rich-water (mean TN: 11.980 mg/L) from two tributaries of Musim Stream and Suknam Stream, which is directly influenced by nearby wastewater disposal plants. Seasonal analysis of water chemistry showed that summer monsoon rainfall was one of the important factors influencing the water quality, and water quality had a large spatial heterogeneity during the rainfall period. In the premonsoon, BOD in the downstream averaged $6.0{\pm}2.47mg/L$, which was 1.4-fold greater than the mean of upstream reach. Mean of CHL-a as an indicator of primary productivity in the water body, was > 2.2 - 2.9 fold in the downstream than in the upstream, and this was a result of the high phosphorus loading from the watershed. Overall, our data suggest that some nutrient controls in point-source tributary streams are required for efficient water quality management of Miho Stream.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2002.10a
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• pp.393-396
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• 2002

The objectives of the paper are to develop the infra-technologies for reclaiming the effluents from wastewater treatment plants and reusing for agriculture water. The Suwon wastewater treatment plant has been selected for wastewater reuse tests and the water quality and treatment efficiencies are investigated. Three levels of wastewater treatments that are the effluent from the plant, sand filtering, and ultra-violet treatment are applied in the pilot system. The randomized block method was applied to wastewater application to paddy rice with five treatments, three blocks, and two replica. The control was the plots with groundwater irrigation, the other treatments are to use polluted stream flow by pumping, in addition to three wastewater treatments. The block test plots and field plots have been monitored for the water quality, soil pollution, and health hazards during the crop stages.

• Korean Journal of Ecology and Environment
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• v.40 no.4
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• pp.560-568
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• 2007

The objectives of this study were to analyze ecological effects on effluents from the Sagok Stream (Chonnam province) as an abandoned mine drainage through necropsy-based health assessments and fish exposure tests, and to conduct In situ field pilot tests for restoration of stream water. Also, we analyzed water quality including general parameters and heavy metals. The tests were performed three times on April 2005, April 2006, and April 2007. Also, we constructed a reactor facility in the outflowing point of the abandoned mine for the remediation of AMD wastewater. In lab test, death rates in all three treatments were ${\geq}50%$ in the experiments. Necropsybased fish tissue assessments using the Health Assessment Index (HAI), indicated that the most frequently damaged tissue was liver (average: 20.8). Values of Health Assessment Index were lower in the control than any other treatments of T1, T2, and T3 and three treatments showed a distinct toxicity impacts by the AMD. In situ lethal test, concentration of Fe, Al and Zn decreased particularly by 85%, 99% and 94%, respectively through the disposal facility. Values of pH, ranged from 3.1 to 7.0, increased by 2.3 fold (mean=5.1) along with the reduction of metal contents. All fishes in P1 cage died 100% on 3 days later after the experimental setting, while all fishes in the P6 died 100% on 9 days later. Overall, these results evidently provide a key methodology for pilot test using the disposal facility and also clarify the toxicity of AMD once again, so this approach used in the pilot facilities here may reduce the acidic and toxic effects in the abandoned mining drainage.