• Journal of Korean Society of Water and Wastewater
• /
• v.25 no.5
• /
• pp.699-706
• /
• 2011

This study has a purpose of examining technical feasibility of supplying the in-stream flow for the Gyobang cheon by using treated water from small wastewater treatment facilities as a decentralized option. To do this, the water and contaminant flow in study areas of the Gyobang cheon are defined from the context of the integrated urban water cycle, and analyzed by using the Urban Volume and Quality (UVQ) model. First, the UVQ model was built for the study areas of the Gyobang cheon and calibrated with observation data. Second, the decentralized options of the in-stream flow was explored with consideration of availability of water sources. The UVQ simulation then led to selecting the best option which would meet the criteria of water quantity and quality. It was finally concluded that using water sources out of study areas 1 and 2, adjoining the upper part of the Gyobang cheon, in the decentralized manner can be a feasible option for in-stream flow. It also seems that the UVQ model is useful to understand the water cycle in study areas of the Gyobang cheon.

• Advances in environmental research
• /
• v.1 no.3
• /
• pp.181-189
• /
• 2012

Trihalomethanes, produced as a result of chlorination of drinking water, are considered a potential health hazard. The trihalomethane formation potential (THMFP) of a raw water source may indicate the maximum trihalomethanes (THMs) that are likely to be produced when chlorine reacts with natural organic matter (NOM) present in the water. A study was conducted to evaluate the THMFP in seven different drinking water sources in the vicinity of Kalpakkam, a rural township, on the east coast of India. Water from seven stations were analysed for THMFP. THMFP was compared with surrogate parameters such as dissolved organic carbon (DOC), ultraviolet absorbance ($UV_{254}$) and bromide. The data showed that THMFP was high in water from open wells as compared to closed bore wells, possibly due to more photosynthetic activity. Proximity to sea, and consequently the levels of bromide, was an important factor that influenced THM formation. THM surrogate parameters showed good correlation with THMFP.

• Proceedings of the KSRS Conference
• /
• 2002.10a
• /
• pp.506-506
• /
• 2002

S. Korean Government has accelerating its efforts to enhance the quality of the drinking water. The Ministry of Environment has declared the law of securing water-pollutant buffering zone to minimize the inflow of the point and nonpoint sources into the drinking water sources. As a first phase of installing nationa-wide water-pollutant buffering zone, approximately 300km buffering zone has been delineated along the South and North Han river, the major drinking water sources for the capital area of S. Korea, which has the population of more than 12 millions. The buffering zone has the width of 1,000 meter for the special protection area, and 500 meter for the remaining area from both ends of the river. The major works have been done in three stages. Firstly, the boundaries lines of the buffering zone was delineated on the digital topographic maps. Secondly, the maps were overlayed with the cadastral maps to identify individual land parcels, the street address of the major pollutant discharging facilities, and all different types of pollutants including livestocks. Thirdly, the field work has been done as a verification. Once the buffering zone was generated, all the information for the buffering gone were created or imported from other government agencies including official land price, details of the major manufacturing facilities discharging considerable amount of pollutants, major motels and resorts, not to mention of restaurants, etc. Also, major livestock houses were located to identify the path of the pollutant inflow to the drinking water source. Further works need to be continued such as purchasing private lands within the buffering zone and change the land use in the efforts to decrease the pollutant amount and to provide more environmentally friendly space. Also, high resolution satellite imagery should be utilized in the near future as a cost-effective data source to update all the landuse activities within buffering zone.

• Journal of Environmental Science International
• /
• v.28 no.1
• /
• pp.37-54
• /
• 2019

The groundwater quality through livestock excreta survey based on "Act of the management and use of livestock excreta" was investigated by selecting sampling sites within 1 km of the farmland without considering hydrogeological units. However, these sites can be affected by various pollution sources such as chemical fertilizers and livestock excretions. Additionally, the effects of pollution sources on groundwater quality in the sites cannot be clearly distinguished from naturally occurring backgrounds. In this study, a method was developed to select the sampling sites for groundwater quality through livestock excreta survey in order to understand the effects of pollution sources especially livestock excreta. First, the concentrations of nitrate within the radius of 200 m, 300 m, 500 m and 750 m, respectively, from the farms regarded as pollution sources in hydrogeological units were compared in 2016-2017. All the nitrate concentrations at 200 - 500 m from the farms exceeded a background concentration, 13.3 mg/L. Those at 750 m and the background concentrations measured by the Ministry of Environment were comparable. Therefore, the appropriate radius was suggested as 500 m for livestock excretions survey. In this study, the areas within 500 m from the farms could be considered under the influence of livestock excretions, while those beyond 500 from the pollution sources as background in hydrogeological units. The developed method was validated by applying it to the sites selected based on both administrative divisions and watersheds for livestock excretion survey. The average densities for the developed method were 0.82 and 0.39 points/km2, respectively, which were considered as appropriate levels according to those of the European Environmental Agency.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2008.05a
• /
• pp.2122-2126
• /
• 2008

With the degradation of water quality and, at the same time increased water usage, the sources of high quality, for examples, river/stream, municipal reservoir, wells, artisan and surface water, are diminishing. Therefore, the importance of water quality has been emphasized over the years through publications and various literature sources. Even though considerable research has resulted in significant strides for providing interpretive information and mitigation strategies for improvement of waters, the quality of which is still questionable. This study aims to propose a completely independent self-contained system for purifying waters, solar-powered ozone generator. It is a semi-permanent and cost effective environmental solution. Functions of ozone treatment are: 1) to maintain oxidative flexibility, 2) remove harmful chemicals, wastes, and other substances, and 3) prevent epizootic microbial outbreaks. Recent advances in technology have allowed the development of the practical, self-contained and independent solar powered device. Solar electrical producing panels that charge batteries are the key to using these systems anywhere electrical power is not available. This paper invites the readers to examine the problem and consider the viable, proven solution the solar powered ozone purifying system. This paper also introduces basic concept and background of solar powered ozone generators and examine its feasibility for improving water quality in rivers and streams.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2022.05a
• /
• pp.156-156
• /
• 2022

Explicitly spatially distributed and reliable data on industrial water demand is very much important for both policy makers and researchers in order to carry a region-specific analysis of water resources management. However, such type of data remains scarce particularly in underdeveloped and developing countries. Current research is limited in using different spatially available socio-economic, climate data and geographical data from different sources in accordance to predict industrial water demand at finer resolution. This study proposes a random forest regression (RFR) model to predict the industrial water demand at 0.50× 0.50 spatial resolution by combining various features extracted from multiple data sources. The dataset used here include National Polar-orbiting Partnership (NPP)/Visible Infrared Imaging Radiometer Suite (VIIRS) night-time light (NTL), Global Power Plant database, AQUASTAT country-wise industrial water use data, Elevation data, Gross Domestic Product (GDP), Road density, Crop land, Population, Precipitation, Temperature, and Aridity. Compared with traditional regression algorithms, RF shows the advantages of high prediction accuracy, not requiring assumptions of a prior probability distribution, and the capacity to analyses variable importance. The final RF model was fitted using the parameter settings of ntree = 300 and mtry = 2. As a result, determinate coefficients value of 0.547 is achieved. The variable importance of the independent variables e.g. night light data, elevation data, GDP and population data used in the training purpose of RF model plays the major role in predicting the industrial water demand.

• Journal of Korean Society on Water Environment
• /
• v.24 no.6
• /
• pp.750-757
• /
• 2008

This study is conducted to characterize and evaluate delivered pollutant loads of point and nonpoint source on the upper watershed of lake paldang. The study area consists of 12 watersheds in Namhan-river and Kyungahcheon, which are approximately 80% of total area of Namhan-river and Kyungahcheon. Based on daily delivered loads from watersheds, 61% of $BOD_5$, 81% of T-N and 70% of T-P were from nonpoint sources, suggesting that delivered loads of nonpoint pollutants be crucial to water quality. On the other hand, 78% of $BOD_5$, 92% of T-N and 87% of T-P as delivered load were from nonpoint sources in an upper watershed of Namhan-river, while 48% of $BOD_5$, 70% of T-N and 57% of T-P as delivered load were from nonpoint sources in a lower watershed of Namhan-river, suggesting higher dependency of point sources than upper watershed of Namhan-river. In the characteristic of delivered loading pollutants from point and nonpoint pollution sources, delivered load of nonpoint pollutants differed significantly by seasonal flow, and as though discharged load of point pollutants were yearly uniform, delivered load of point pollutants was found to be flow-dependent because its delivery ratio was changed.

• Journal of Environmental Health Sciences
• /
• v.35 no.5
• /
• pp.376-385
• /
• 2009

The characteristics of Lake Cheonhoji water and sediment were investigated in oder to utilize these as fundamental materials for the management of lake water quality. The hydrographic properties of Lake Cheonhoji which are relatively low chance of nutrients loading from the watershed and a long retention time of lake water, lead to the probability of high lake productivity. It was also observed that lake water showed stratification during summer and complete mixing during fall, even though water depth was relatively shallow. The trophic state was eutrophic to hypertrophic from summer to late fall. The overall properties of the sediment were oligohumic, high ignition loss and high composition of NAIP and Resid.-P, which might serve as potential pollution sources of lake water quality. In laboratory scale experiments, it was observed that leaching potential of nutrients in the sediment was greatly dependant upon water temperature and dissolved oxygen. Finally, water pollution in Lake Cheonhoji was considered to be largely due to the adverse cycle of uncontrollable eutrophication, which resulted in the subsequent occurrence of dead algae and animal plankton, organic sedimentation, reduction of dissolved oxygen and nutrients leaching, which again reinforced the cycle of eutrophication in the lake.

• Journal of Environmental Science International
• /
• v.18 no.6
• /
• pp.683-690
• /
• 2009

The water quality of reservoir can be controled by water quality prediction model because it can not only grasping the present water state but also predicting the water quality in future. In this study, WASP model is used to predict the water quality of Chungju reguration reservoir. This model has some special option which predicts the pollutant outflow phenomenon caused by the contamination sources. So this model is widely used because that can present the scientific basis in this field. This model can help the managers make the right choice of water quality policy. Environmental grade of Chungju reguration reservoir is in III,IV grade which is in bad condition comparatively. The water contamination will be in poor as the year passes. When considering T-N, T-P which are the nutrient to control eutrophication, the concentrated administration about contamination sources is in urgent.

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