• 한국해안해양공학회지
• /
• 제14권2호
• /
• pp.108-115
• /
• 2002

만경강·동진강 유역의 오염물질 유출모형을 수립·적용하였다. 모형의 입력자료인 유역정보 및 오염원 정보는 GIS도구를 이용하여 추출·분석한 자료를 이용하였으며, 월별 유출량 및 하천의 오염물질 농도 관측자료와 모형의 계산결과를 비교·분석하였다. 분석결과, 유역유출량은 여름철에 약간 과소 추정하고 있으나 전체적인 변화경향은 일치하고 있다. 또한 모형에서 계산된 오염물질 농도는 10년 평균 수질자료와 1999년도 월별 수질자료를 이용하여 비교하였다. 그 결과, 익산천에서는 크게 과소 추정하고 있으나, 전체적으로는 양호한 정도로 일치하고 있는 것으로 파악되었다 익산천에서 과소 추정하는 이유는 오염퇴적물에 의한 국지적 영향으로 사료되며, 오염퇴적물이 수층에 미치는 영향을 규명하기 위해서는 하천의 퇴적물 오염도 관측·분석을 통한 심도깊은 연구가 수행되어야 할 것이다

• 한국수산과학회지
• /
• 제54권4호
• /
• pp.480-488
• /
• 2021

The term residence time is defined as the time taken for substances in a system to leave the system and is a useful concept to explain the physical environment characteristics of a coastal area. It is important to know the spatial characteristics of the residence time to understand the behavioral properties of pollutants generated in a marine system. In this study, the spatial distribution of average residence time was calculated for Gangjin Bay, Korea, using a hydrodynamic model including a particle tracking module. The results showed that the average residence time was about 10 days at the surface layer and about 20 days at the bottom layer. Spatially, this was the longest residence time in the southwestern sea. There was no significant difference in average residence time at the surface layer due to freshwater discharge, but spatial variation at the bottom layer was larger. The average residence time at the bottom layer decreased in the southwestern area due to freshwater discharge and increased in the northern area. This result suggests that the residence time of anthropogenic pollutants may have a large spatial difference depending on the freshwater discharge, and thus the time taken to influence cultured organisms may also vary.

• Environmental Engineering Research
• /
• 제10권3호
• /
• pp.144-154
• /
• 2005

The use of ozone gained acceptance in the production of ultrapure water because of its powerful oxidizing ability. Ozone is currently used to deactivate microorganisms and remove organic contaminants. However, interest also exists in using radical species, which arc stronger oxidants than ozone, in such processes. One means of producing radical species is by corona discharge. This work investigates the use of a novel pulseless corona-discharge system for the removal of organic substances in ultrapure water production. The method combines corona discharge with electrohydrodynamic spraying of oxygen, forming microbubbles. Experimental results show that pulseless corona discharge effectively removes organics, such as phenol and methylene blue, in deionized water. The corona-discharge method is demonstrated to be comparable to the direct use of ozone at a high-applied voltage. The results also show that a minimum applied voltage exists for operation of the corona-discharge method. In this work, the minimum applied voltage is approximately 4.5 kV. The kinetic rate or phenol degradation in the reactor is modeled. Modeling results show that the dominant species of the pulseless corona-discharge reactor are hydroxyl radical and aqueous electron. Several radical species produced in the pulseless corona-discharge process are identified experimentally. The. major species are hydroxyl radical, atomic hydrogen species, and ozone.

• 한국해안해양공학회지
• /
• 제10권3호
• /
• pp.132-140
• /
• 1998

진해·마산만은 오염부하량의 측정자료가 미흡하기 때문에 오염부하량에 대한 정량적인 분석·평가연구가 수행될 수 없었을 뿐만 아니라, 연안의 수질변화를 예측하는 수질모형의 다각적인 보정·검증작업이 제한적으로 이루어 질 수 밖에 없었다. 본 연구에서는 진해·마산만 22개 하천과 해양방류관을 통한 오염부하량을 측정하고, 해역내 3개 지점에서 오염물질 용출률을 측정하였다. 마산·창원 유역의 오염부하량은 진해·마산만 전체 오염부하량의 80∼90% 정도를 차지하고 있으며, 해양방류관에 의한 오염부하량은 20∼25%를 차지한다. 또한, 퇴적물로부터의 오염부하량이 유역 오염부하량과 대등하기 때문에, 퇴적물로부터 용출되는 오염물질량은 하계 수질악화 및 동계 수질양호의 계절적인 변화를 결정하는 주요한 인자 중의 하나로 파악되었다.

• 한국해안해양공학회지
• /
• 제11권1호
• /
• pp.41-49
• /
• 1999

진해·마산만의 장기 수질변동을 예측할 수 있는 평면 2차원 수질계산 모형을 구성하였다. 유역내 22개 하천의 오염부하량 및 해역내 16개 정점의 수질을 월별, 계절별로 관측 (1995.5~1996.4)하여 모형의 보정·검증자료로 이용하였으며 저면퇴적물로부터의 오염물질 용출률을 측정하여 저층에서의 지역적 오염편차를 반영하였다. 구성된 모형을 적용하여 하계의 농도분포를 모의한 결과는 다음과 같다. 하천을 통한 오염물질 유입지점의 오염도가 매우 높으며, 외해방향으로 급격하게 농도가 감소하는 경향을 보이고 있다. 특히 마산만으로 유입되는 다량의 오염물질은 해역의 정체성으로 대부분이 침전되어 저질의 오염을 가중시키고 있다. 방류수역에서는 질소 및 인이 미처리상태로 방류되기 때문에, 해역의 부영양화가 진행되고 있는 것으로 파악되었다.

• 한국물환경학회지
• /
• 제31권6호
• /
• pp.653-664
• /
• 2015

TPLMS (Total water pollutant load management system) that is the most powerful water-quality protection program have been implemented since 2004. In the implementation of TPLMS, target water-quality and permissible discharged load from each unit watershed can be decided by water-quality modeling. And NPS (Non-point sources) discharge coefficients associated with certain (standard) flow are used on estimation of input data for model. National Institute of Environmental Research (NIER) recommend NPS discharge coefficients as 0.15 (Q₂₇₅) and 0.50 (Q₁₈₅) in common for whole watershed in Korea. But, uniform coefficient is difficult to reflect various NPS characteristics of individual watershed. Monthly NPS discharge coefficients were predicted and estimated using surface flow and water-quality from HSPF watershed model in this study. Those coefficients were plotted in flow duration curve of study area (Palger stream and Geumho C watershed) with monthly average flow. Linear regression analysis was performed about NPS discharge coefficients of BOD, T-N and T-P associated with flow, and R² of regression were distributed in 0.893~0.930 (Palger stream) and 0.939~0.959 (Geumho C). NPS Discharge coefficient through regression can be estimated flexibly according to flow, and be considered characteristics of watershed with watershed model.

• 한국환경과학회지
• /
• 제18권9호
• /
• pp.983-992
• /
• 2009

The purpose of the present study is to analyze pollutant runoff characteristics from non-point sources in Joman River basin. The present study contains analyzed results of rainfall and SS, BOD, COD, TN, TP runoff from Joman River basin. This study contains a sensitivity analysis of parameters that affect the simulation results of rainfall and pollutants runoff. Result of the sensitivity analysis shows that proportion of watershed and impervious areas is the most sensitive to peak discharge and total flowrate for rainfall runoff and that WASHPO is the most sensitive parameter for pollutants runoff. For parameter estimation and verification, flowrate and water quality is measured at the Kangdong Bridge in Haeban stream. A single rainfall event is use to perform parameter estimation and verification. Results of the present study show that total pollutant loads of Joman River basin is 11,600 ton of SS, 452 ton of BOD, 1,084 ton of COD, 515 ton of TN, and 49 ton of TP, respectively. In addition, it is found that contribution ratio of non point source and total source is 89% of SS, 63% of BOD, 61% of COD, 21% of TN, and 32% of TP, respectively.

• 한국농공학회논문집
• /
• 제54권6호
• /
• pp.53-63
• /
• 2012

The objectives of this study were to develop a linked watershed-waterbody modeling system and to assess the impacts of indirect wastewater reuse on irrigation water quality. The Osan stream watershed within Gyeonggi-do of South Korea was selected for this study. The linked modeling system was composed of the SWAT (Soil and water assessment tool) and QUALKO2 models. The SWAT model was calibrated and validated using the stream discharge and water quality data from 2010 to 2011. Runoff and non-point source pollutants from each subbasin and stream discharge from 1980 to 2009 were simulated by the SWAT model and applied to the QUALKO2 model. The QUALKO2 model was calibrated and validated under the conditions of low water and normal discharges, respectively. Finally, The 10-day irrigation water quality from April to September was simulated. The statistical measures of coefficient of determination ($R^2$), reliability index (RI), and efficiency index (EI) were used to evaluate the system performance. The $R^2$, RI and EI values ranged from 0.5 to 1.0, 1.03 to 1.92, and -35.03 to 0.95, respectively. The 10-day irrigation water quality showed the concentrations of BOD and coliform exceeded the water quality guidelines for wastewater reuse. The linked modeling system can be a useful tool to estimate non-point source pollutant loads in watershed and to control the water quality of effluent from a wastewater treatment plant and irrigation water in the downstream waterbody.

• 한국물환경학회지
• /
• 제31권3호
• /
• pp.295-303
• /
• 2015

In Korea, Total Maximum Daily Loads(TMDLs) has been enforced to restore and manage water quality in the watersheds. However, some assesment of implementation plan of TMDLs showed that the achievement of the target water quality is not related to the proper allocation loads because difference of flow duration interval. In the United States, the discharge loads are determined by water quality modeling considering standard flow conditions according to purpose. Therefore, this study tried to develop the allocation method considering economical efficiency using water quality model. For this purpose, several allocation methods being used in the management of TMDLs is investigated and develope an allocation criteria considering regional equality and uniformity. Since WARMF(Watershed Analysis Risk Management Framework) model can simulate the time varying behavior of a system and the various water quality variables, it was selected for a decision support system in this study. This model showed fairly good performance by adequately simulating observed discharge and water quality in Miho watershed. Furthermore, the scenario simulation results showed that the effect of annual average water quality improvement to remove 1kg BOD is more than 25 times, even if point pollutants treatment facility is six times more expensive to operate than non-point pollutants treatment facility.

• 한국환경과학회지
• /
• 제16권4호
• /
• pp.505-521
• /
• 2007

This study estimated response of water duality and pollutant behavior according to the discharge and reuse of treated wastewater by three-dimensional eco-hydrodynamic model, and suggest plan that water quality management and environmental restoration in the coastal area including urban stream of Yeosu, Korea. Dispersions of low-saline water and COD by treated wastewater loads (design facility capacity, about $110,000m^3/d$) were very limited in near of effluent site. Nutrients, however, increase compared to the other water quality factors, especially total nitrogen was very sensitive to input loads. When reuse some of treated wastewater to Yeondeung stream, nitrogen was big influence on estuarine water quality. Although current characteristics of treated wastewater such as discharge and water quality were negligible to the change of marine environment, effluent concentration of COD, TN and TP, especially 40% of TN, are reduced within the allowable pollutant loads for satisfy environmental capacity and recommended water duality criteria. Also, controls of input point/non-point sources to Yeondeung stream and base concentration of pollutants in coastal sea itself are very necessary.