• 상하수도학회지
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• 제26권5호
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• pp.705-712
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• 2012

Selecting Daechung Dam as a sample study site, this study simulates virtual water quality incident which can be occurred using EFDC maintained by USEPA. In order to predict the behavior and diffusion of leaked conservative pollutant within dam under the worst condition, the hydrological data and information from 2008 were used. EFDC was successfully calibrated for observed water level obtained from the above sources. From the results of simulations, even though the concentrations (500 ppm, 1,000 ppm and 10,000 ppm) of leaked pollutant were different with each other at the same sources, the travel time of each peak concentration appeared similar. Also, changing the leak source point from dam gate(0 km) to 7 km, it was found that as leak source point was nearer to the dam gate, the travel time of each peak concentration showed up sooner. It was simulated to take 1 day to 15 days for initial appearance of the leaked pollutant according to the leaked points, and 3 days to 25 days for the reach of the peak concentration, respectively.

• 환경영향평가
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• 제23권3호
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• pp.177-186
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• 2014

Depending on the change of lifestyle and the improvement of people's living standards and rapid industrialization, urbanization of recent, demand for water is increasing rapidly. So emissions of domestic wastewater and various industrial waste water has increased, and water quality is worsening day by day. Therefore, in order to provide a measure against the occurrence of water pollution accident, this study was tried to simulate water pollution accident. This study simulated 2008 Gimcheon phenol accident using 1,2-D model, and analyze scenario for prevent of water pollution accident. Consequently the developed 1-D model presents high reappearance when compared with 2-D model, and has been able to obtain results in a short simulation run time. This study will contribute to the water pollution incident response prediction system and water quality analysis in the future.

• 한국수자원학회논문집
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• 제56권12호
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• pp.845-853
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• 2023

최근 화학사고 증가와 함께 사고로 인한 재해에 대한 건수가 2012년부터 계속적으로 증가하고 있으며 국내 화학물질 사고 대표 사례인 구미 불산 사고를 보았을 때, 사고현장에 적용 가능한 기술이 미흡하여 피해가 확산되었다는 결과가 발생하였다. 따라서 본 논문에서 수질오염사고 대응체계를 위치기반에 맞춰 화학사고 발생 시 수환경에서 실시간 대응을 위한 위치기반의 지표측정방식의 GPS전자부자를 이용한 대체지표 추적에 대한 측정방법과 그에 대한 연구결과를 소개하고자 한다. 연구대상지는 불산사고가 발생했었던 지역인 구미시를 대상으로 김천시와 구미시 등 2개 시 로 이루어진 감천을 선정하였고 해당 대상지에 수질-수리 측정을 통해 GPS전자부자를 이용한 대체추적물질 추적에 대한 실험을 진행하였다. 이를 통해 GPS전자부자를 이용한 추적자실험에 있어 수질-수리 측정이 동시에 가능하며, 특히 해당 연구결과를 통해 GPS 전자부자를 활용한다면 하천 분야에서의 유출사고에 대한 재난대응체계에 상당히 도움이 될 것으로 사료된다.

• 한국물환경학회지
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• 제26권4호
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• pp.700-706
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• 2010

Along the 4 major rivers in korea, there are automatic water quality monitoring (AWQM) stations to immediately respond to any pollution incident. Real-time data (temperature, DO, pH, EC and TOC) collected at each station were statistically treated to exclude outliers and keep valid data using Dixon's test and Discordance test. These applied methods were compared in terms of the number of the outliers sorted out. There was no significant difference between these methods. On the other hand, more outliers were sorted out from EC and TOC data, comparing with other water quality items. EC data did not show partly any variation for a long time at H station. If measured signal does not exceed ${\pm}0.001mS/cm$ from the sectional mean, the signal should be treated as normal data. Therefore, another routine was added to the data screening system, some data which were removed as outlier were restored.

• 생태와환경
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• 제43권2호
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• pp.338-344
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• 2010

상수원 및 수계의 수질관리 업무를 효율적이고 능동적으로 수행하고, 수질오염사고 발생시 신속한 대응조치를 할 수 있는 조기경보체계 구축을 위하여 주요 상수원 및 하천 등에 수질자동측정망을 설치하여 운영하고 있다. 수온, pH, EC, DO, TOC 항목에 대한 정도평가를 실시하여, 수질자동 측정 자료에 대한 정확도를 확보하여 신뢰도를 제고하고자 하였다. 수질자동측정기기와 수동측정기기에 대한 측정값을 비교한 결과, 대체로 일반항목(수온, pH, EC, DO) 및 TOC의 상대정확도가 20% 이내의 목표를 만족하였다. 그러나 수질자동측정소의 저류수조의 측정기기(내부)와 채수지점의 측정기기(외부)의 측정값 차이를 분석한 결과, 채수거리가 먼 측정소의 DO에 대한 내부-외부의 상대정확도는 목표값을 다소 벗어나는 것으로 나타났다. 채수관로에 조류 및 미생물 부착에 의한 오염이 원인으로 판단되어 역세척하여 측정한 결과, 측정된 DO 농도는 최대 53%까지 상승하는 효과를 나타냈다. 따라서 채수관로 관리가 수질자동측정 자료의 신뢰성을 확보하는데 중요함을 알 수 있었다.

• 한국컴퓨터정보학회논문지
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• 제21권8호
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• pp.57-64
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• 2016

Initial prevention activities and rapid propagation conditions is the most important to prevent diffusion of water pollution. If water pollutants flow into streams river or main stresm located in environmental conservation area or water intake facilities, we must predict immediately arrival time and the diffusion concentration to the proactive. National Institute of Environmental Research developed water pollution incident response prediction system linking dam and movable weir. the system is mathematical model which is updated daily. Therefore it can quickly predict the arrival time and the diffusion concentration when there are accident of oil spills and hazardous chemicals. Also we equipped with mathematical model and toxicity model of EFDC(Environmental Fluid Dynamics Code) to calculate the arrival time and the diffusion concentration. However these systems offer the services of an offline manner than real-time control services. we have ensured the reliability of data collection and have developed a real-time water quality measurement data transmission device by using the data linkage utilizing a mode bus communication and a commercial SCADA system, in particular, we implemented to be able to do real-time water quality prediction through information infrastructure of the water quality integrated management business created by utilizing the construction of the real-time prediction system that utilizes the data collected, the Open map, the visual representation using charts API and development of integrated management system development based on web maps.

• 상하수도학회지
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• 제37권5호
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• pp.261-269
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• 2023

In light of recent social concerns related to issues such as water supply pipe deterioration leading to problems like leaks and degraded water quality, the significance of maintenance efforts to enhance water source quality and ensure a stable water supply has grown substantially. In this study, scan statistic was applied to analyze water quality complaints and water leakage accidents from 2015 to 2021 to present a reasonable method to identify areas requiring improvement in water management. SaTScan, a spatio-temporal statistical analysis program, and ArcGIS were used for spatial information analysis, and clusters with high relative risk (RR) were determined using the maximum log-likelihood ratio, relative risk, and Monte Carlo hypothesis test for I city, the target area. Specifically, in the case of water quality complaints, the analysis results were compared by distinguishing cases occurring before and after the onset of "red water." The period between 2015 and 2019 revealed that preceding the occurrence of red water, the leak cluster at location L2 posed a significantly higher risk (RR: 2.45) than other regions. As for water quality complaints, cluster C2 exhibited a notably elevated RR (RR: 2.21) and appeared concentrated in areas D and S, respectively. On the other hand, post-red water incidents of water quality complaints were predominantly concentrated in area S. The analysis found that the locations of complaint clusters were similar to those of red water incidents. Of these, cluster C7 exhibited a substantial RR of 4.58, signifying more than a twofold increase compared to pre-incident levels. A kernel density map analysis was performed using GIS to identify priority areas for waterworks management based on the central location of clusters and complaint cluster RR data.

• Ocean and Polar Research
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• 제25권spc3호
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• pp.423-426
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• 2003

The seawater exchange breakwater equipped with an oscillating water channel and water transmitting pipes has a very spectacular function that seawater supply can be greatly increased due to the upsurge of the water surface inside the channel at resonance condition which can be reached when the incident wave period becomes close to the natural period of the channel. The variations of the water level and period inside the channel are very important factors in enhancing the efficiency of sea water exchange, especially when designing the breakwater cross-section in shallow water zone which requires longer resonance period with the elongated horizontal projection of the channel. In the present study, a hydraulic experiment was performed varying the length of the oscillating channel, and the resonance periods and water surface variations are analyzed in terms of water transmission through the pipes.

• 한국해양공학회지
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• 제21권5호
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• pp.18-24
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• 2007

The environmental value of coastal vegetation has been widely recognized. Coastal vegetation such as reed forests and seaweed performs several useful functions, including maintaining water quality, supporting fish (and, thus, fisheries), protecting beaches and land from wave attack, stabilizing sea beds and providing scenic value. However, studies on the physical and numerical process of wave propagation, sediment transport and bathymetric change are few and far between compared to those on the hydrodynamic roles of coastal vegetation. In general, vegetation flourishing along the coastal areas attenuates the incident waves through momentum exchange between stagnated water mass in the vegetated area and rapid mass in the un-vegetated area. This study develops a numerical model for describing the wave attenuation and sediment transport in a wave channel in a vegetation area. By comparing these results, the effects of vegetation properties, wave properties and model parameters are clarified.

• 상하수도학회지
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• 제25권1호
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• pp.95-106
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• 2011

Even though MBR processes have many advantages such as high quality effluents, a small footprint and convenience for operation compared to conventional activated sludge processes, there are some shortcomings in terms of the cost and potential fouling incident that keeps MBR (Membrane bioreactor) processes from being widely applied. To reduce these problems, PTFE (Polytetrafluoroethylene) flat sheet membranes that have excellent permeability and durability were tested instead of PVDF (Polyvinylidene fluoride) membrane which is being used widely in water treatment. Low concentration of sodium hydroxide (NaOH) was also added into the membrane modules in order to prevent the membrane fouling as well as to provide the alkalinity. With conditions mentioned above, a pilot-scale MBR system based on the MLE (Modified Ludzack Ettinger) process was operated at flux of 40 $L/m^{2}/hr$ and over 15,000 mg/L MLSS concentration for about 8 months. And coagulant(alum) was added into the membrane tank to remove phosphorus. Although the more coagulant is added the more effectively phosphorus is removed, that can lead to fouling for a long operation(Ronseca et al.,2009). By the way there is a research that fouling grow up after stopping injection of coagulant(Holbrook, 2004). Stable operation of MBR systems was achieved without major chemical cleaning and the effluent quality was found to be good enough to comply with the treated waste water quality regulations of the Korea.