• 한국물환경학회지
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• 제21권4호
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• pp.305-313
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• 2005

In these days, water environment is getting threatened by a variety of toxic pollutants discharged from industries. However, environmental standards and regulations in Korea may be in straitened circumstances to protect the water environment from it. Therefore, the purpose of this review is to compare the management state of the toxic substances in water environment and to present the framework for deriving water quality criteria in USA and Japan. To conserve the water environment from the toxic pollutants more efficiently, the following considerations could be suggested in standards and regulation in Korea. Firstly, there should be consistency of regulated pollutants in drinking water quality standard, water quality standards and permissible wastewater discharge standards. Secondly, in case of deriving the water quality standards, it is required to consider the conservation of the aquatic ecosystem as well as the protection of human health. Finally, it is indispensable to make risk-based approach in management of toxic pollutants in water environment.

• Advances in environmental research
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• 제6권3호
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• pp.203-216
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• 2017

For survival of human beings clean water is an essential commodity whereas contamination in drinking water threatens to mankind. The main cause of water contamination is social and development activities of human being along with increasing population. The community in the study area has acute shortage of drinking water along with about 40 to 60% has no access to safe drinking water. This study indicates drinking water quality of two major sources of coastal belt of Karachi one is supplied by Karachi Water & Sewerage Board (KWSB) as tap water and the other through groundwater. The physicochemical analysis was carried out by following the standard methods for checking the quality of drinking water. The analyzed results showed that the quality of groundwater was unfit as potable water. The most critical situation was observed as high level of contamination followed by high turbidity and increased salinity levels. TDS in surface water were found 12% above and TDS in groundwater was 20% below the National Drinking Water Quality Standards (NDWQS) of Pakistan as well as the permissible WHO drinking water quality guidelines.

• 환경영향평가
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• 제20권5호
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• pp.705-716
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• 2011

For the efficient discovery of knowledge and information from the observed systems, data mining techniques can be an useful tool for the prediction of water quality at intake station in rivers. Deterioration of water quality can be caused at intake station in dry season due to insufficient flow. This demands additional outflow from dam since some extent of deterioration can be attenuated by dam reservoir operation to control outflow considering predicted water quality. A seasonal occurrence of high ammonia nitrogen ($NH_3$-N) concentrations has hampered chemical treatment processes of a water plant in Geum river. Monthly flow allocation from upstream dam is important for downstream $NH_3$-N control. In this study, prediction models of water quality based on multiple regression (MR), artificial neural network and data mining methods were developed to understand water quality variation and to support dam operations through providing predicted $NH_3$-N concentrations at intake station. The models were calibrated with eight years of monthly data and verified with another two years of independent data. In those models, the $NH_3$-N concentration for next time step is dependent on dam outflow, river water quality such as alkalinity, temperature, and $NH_3$-N of previous time step. The model performances are compared and evaluated by error analysis and statistical characteristics like correlation and determination coefficients between the observed and the predicted water quality. It is expected that these data mining techniques can present more efficient data-driven tools in modelling stage and it is found that those models can be applied well to predict water quality in stream river systems.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2022년도 학술발표회
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• pp.475-475
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• 2022

The aim of this study is to identify the significant pollutant sources from the tributaries that are affecting the water quality of the study site, the Geum River and provide a solution to enhance the water quality. Multivariate statistical analysis modles such as cluster analysis, Principal component analysis (PCA) and positive matrix factorization (PMF) were applied to identify and prioritize the major pollutant sources of the two major tributaries, Gab-cheon and Miho-cheon, of the Geum River. PCA identifies three major pollutant sources for Gab-cheon and Miho-cheon, respectively. For Gab-cheon, wastewater treatment plant (WWTP), urban, and agricultural pollutions are identified as major pollutant sources. For Miho-cheon, agricultural, urban, and forest land are identified as major pollutant sources. On the contrary, PMF identifies three pollutant sources in Gab-cheon, same as PCA result and two pollutant sources in Miho-cheon. Water quality control scenarios are formulated and improvement of water quality in the river locations are simulated and analyzed with the Environmental Fluid Dynamic Code (EFDC) model. Scenario results were evaluated using a water quality index developed by Canadian Council of Ministers of the Environment. PCA and PMF appears to be effective to identify water pollution sources for the Geum river and also its tributaries in detail and thus can be used for the development of water quality improvement alternative of the above water bodies.

• 상하수도학회지
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• 제34권4호
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• pp.239-250
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• 2020

In this study, effects of five raw water quality parameters (turbidity, odor compounds caused by algae, filter clogging caused by algae, pH increase caused by algae, and organic matter) on improvements and operations costs of typical water treatment plant (WTP) were estimated. The raw water quality parameters were assumed the worst possible conditions based on the past data and costs were subsequently estimated. Results showed that new water treatment facilities were needed, such as a selective intake system, an advanced water treatment processes, a dual media filter, a carbonation facility, and a re-chlorination facility depending on water quality. Furthermore, changes needed to be made in WTP operations, such as adding powered activated carbon, increasing the injection of chlorine, adding coagulation aid, increasing the discharge of backwashed water, and increasing the operation time of dewatering facilities. Such findings showed that to reliably produce high-quality tap water and reduce water treatment costs, continuous improvements to the quality of water sources are needed.

• 상하수도학회지
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• 제30권1호
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• pp.19-31
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• 2016

The Saemangeum watershed is required to manage water pollution effectively but the effect of liquid manure (LM) on soil and water quality in the basin is not clearly identified as yet. This study aims at assessing the effect on soil of a rice field and water quality of water bodies near the rice field during rice-crop time period to find out the effect of LM, the effect of rainfall, and the effect of rice-crop environment on soil and water quality by analyzing data of nitrogen components. As a result of the LM distribution, $NO_3-N$ was much higher than other N components in the entire soil layers and it was accelerated by rainfall right after the LM distribution. Compared to chemical fertilizer (CF), LM was slightly affected but still influenced on the surface water quality. During weak rainfall, low nitrogen concentration in topsoil was resulted as NH3-N decreased and Org-N and $NO_3-N$ increased. $NO_3-N$ concentration in the water of irrigation canals increased with time. During intensive rainfall, $NO_3-N$ and Org-N of the soil were measured highly in the submerged condition, while the water quality of the rice field was lower due to flooding into the irrigation canal as well as the growth of the rice plants. Also, total nitrogen was increased more than 7 times and it showed serious water quality deterioration due to LM and excessive fertilizer distribution, and rainfall during all rice-crop processes. The effect of LM on water quality should be studied consistently to provide critical data while considering weather condition, cropping conditions, soil characteristics, and so on.

• 한국물환경학회지
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• 제24권5호
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• pp.592-597
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• 2008

Current water quality standard (WQS) in Korea is based on the protection of human health, not considering the protection of aquatic organisms. Most of chemicals can be toxic to ecological biota as well as human. Health of aquatic biota is closely related to the human health via food chain, therefore ecological risk based-WQS needs to be developed to protect the aquatic ecosystem. In this study, we selected the 31 chemicals in the Project entitled 'Development of integrated methodology for evaluation of water environment'. The methodology for calculating water quality criteria was derived from the Australian and New Zealand processes for deriving guideline trigger value for aquatic ecosystem. The available ecotoxicity data were collected from US EPA's ECOTOXicology Database (ECOTOX), TOX-2000 Database, European Chemicals Bureau (ECB)'s International Uniform Chemical Information Database (IUCLID) and Environmental Protection Agency (US EPA)'s report 'Ambient Water Quality Criteria (AWQC)'. The aquatic toxicity data for the Korean species were selected for risk assessment to reflect the Korean water environment. The monitoring values were calculated from the water quality monitoring data four main Korean rivers. We suggested the order of priorities of chemicals based on ecological risk assessment. We expect that these results can be useful information for establishing the WQS for the protection of aquatic ecosystem.

• 한국습지학회지
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• 제20권2호
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• pp.136-144
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• 2018

환경부에서는 유역단위의 통합 물관리를 위하여 물환경관리계획, 수질오염총량제 등을 실시하고 있으며, 측정망에서 측정된 수질을 이용하여 설정된 목표수질의 달성 정도를 판단하고 있다. 유역 하류부에 위치한 측정망의 지점에서의 수질 농도는 유역의 각 지류에서 오염원 유입과 하천의 자정작용 등의 복잡한 메커니즘을 거쳐서 만들어진 결과물이다. 이에 본 연구에서는 유역의 오염원 추적 및 초과율을 이용해 본류 및 지류의 수질이 목표수질 지점에 미치는 영향의 정도에 대하여 분석하였다. 이를 위해 오염총량제의 대상물질인 BOD와 T-P를 포함한 총 6가지의 수질항목에 대하여 FDC와 초과율 분석을 수행하였고, 이를 통해 목표수질 지점에 유황별 영향을 미치는 수질항목 및 지점을 도출할 수 있었다. 본 연구에서 제시한 FDC 분석을 통한 오염원 추적은 목표수질 달성을 위해 지류별 수질관리 전략을 보다 효율적으로 수립할 수 있을 것이다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2012년도 학술발표회
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• pp.36-36
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• 2012

Drainage water in lowland paddy fields is quantitatively influenced recycle and/or repeated irrigation by irrigation facilities, i.e. pumps, check gates, small reservoirs and so on. In those drainage channels, nutrients accumulation and increasing organic matters are considered to be occurred, and water quality would be degraded not only environmental aspect but irrigation purpose. In general, Total Nitrogen (T-N) is interested water quality index in irrigation water, because high nitrogen concentration sometimes caused decreasing rice production by excess growth and fallen or degrading quality of taste, then, farmers would like to clear water less than 1mg/L of T-N concentration. In drainage channel, it is known that the nitrogen concentration change is influenced by physical, chemical and biological properties, i.e, stream or river bed condition, water temperature, other water quality index, and plant cover condition. In this study, discharge data (velocity and level) in a drainage channel was monitored by an Acoustic Doppler system and water quality was sampled at same time in 2011. So those data was analyzed by multi regression model to realize hydrological and environmental factors to influence with nitrogen concentration. The results showed the difference tendency between irrigation and non-irrigation period, and those influenced factors would be considered in water quality model developing in future.

• 한국농공학회지
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• 제45권2호
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• pp.116-125
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• 2003

Predictions of stream water quality require both estimation of pollutant loading from different sources and simulation of water quality processes in the stream. Nonpoint source pollution models are often employed for estimating pollutant loading in rural watersheds. In this study, a conjunctive application of SWAT model and WASP model was made and evaluated for its applicability based on the simulation results. Runoff and nutrient loading obtained from the SWAT model were used for generating input data for WASP model. The results showed that the simulated runoff was in good agreement with the observed data and indicated reasonable applicability. Loading for the water quality parameters predicted by WASP model also showed a reasonable agreement with the observed data. It is expected that stream water quality could be predicted by the coupled application of the two models, SWAT and WASP, in rural watersheds.