• Korean Journal of Environmental Agriculture
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• v.16 no.2
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• pp.199-205
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• 1997

Water quality of streams and ground water from areas of different agricultural practices in the small catchments of the Han River basin was investigated. Water samples were collected from upper, middle and lower reaches of the Han River Basin where three types of agricultural management have been practiced : (1) highland agriculture and livestocks in Daegwanryung area, (2) typical upland and paddy farmings in Dunnae (Jucheon River) and Chuncheon (Soyang River) areas, and (3) intensive farming in the plastic film house in Guri area (Wangsuk stream). Water quality was monitored for EC, pH, COD, TSS, N, rations and anions. Concentrations of N, especially nitrate, and phosphorus in both stream and ground water exceeded the standard water quality criteria in many cases, but those of heavy metals were non-detectable or trace in most cases, except for Wangsuk stream where a high level was detected in a specific sampling time. Chemical criteria such as pH, EC and COD of the stream were suitable for irrigation purpose, but nitrate concentrations in ground water used in the intensive plastic film house were high enough to require a special management consideration. A model on the irrigation water quality incorporating EC and nitrate concentrations was suggested in view of fertilizer management and environmental quality.

• The KIPS Transactions:PartD
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• v.11D no.1
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• pp.31-38
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• 2004

This paper is about to implement a system for ground water safety evaluation. Since ground water quality is affected from the contamination source of surface water, one can estimate the magnitude of affection and the source themselves. This paper suggests a method to evaluate the spatial relationship of ground water and its contamination sources, using“contain”and“distance”operators in GIS. The research area is the Kunsan City in Chonbuk province, and are 75th wells those are located between the 4th alluvium land types. The results of measured chemical factors and results of related evaluation of these wells are stored and represented in ZEUS 2000 GIS DBMS, and an interface for searching and studying, is implemented by using ZEUS/SQLX, ZEUS/COM, and Visual Basic 6.0 programming languages. After this research, the spatial relationship between hydro-geological geo-objects and ground water is verified and a efficient evaluation system using GIS is suggested. It is the topic of further study that tries to calibrate the suggested evaluation model by applying it to wider area.

• Journal of Korean Society of Water and Wastewater
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• v.12 no.2
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• pp.83-89
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• 1998

The drinking water supply in Cheju entirely depends on the ground water and recently the polluted ground water bores are increasing. In 1993 Cheju Province Health-Environment Institute reported that the ground water quality of 26 of 98 bores under the drinking water quality standard. Therefore there are many investigation in the needs of the nitrate removal in the drinking water in the regin with no alternative water resources. In this study, the following results are obtained to remove the nitrate in biofilm filtration process in which uses ethanol as external carbon source. Over 90% of nitrate is removed after 10 days of experiment. The nitrate removal rate on filtration velocity is about 100% at 50m/day and 100m/day, and about 56% at 200m/day. The removal rate is reduced in 27% at 400m/day. Using ethanol as the external carbon source, denitrification kinetic is 1st-order. Denitrification constant k is 8.004($hr^{-1}$). The amount of the denitrificated-Nitrogen is increased as the contact time increased. Deoxydation rate constant ${\gamma}$ is 11.895($hr^{-1}$). 0.968g of ethanol(as TOC) is needed to remove 1g of nitrate and 0.291g is required to remove 1g of dissolved oxygen.

• Journal of environmental and Sanitary engineering
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• v.12 no.2
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• pp.43-49
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• 1997

Iron and manganese problems in ground water affect far more water systems than almost any other water quality concern. The purpose of this study is to find the optimum condition of ozonation for the removal of dissolved iron, manganese and other organics in the polluted ground water. We proposed 4mg/l, 8mg/l as optimum ozone dose for the removal of $Fe^{2+},{\;}Mn^{2+}$, respectively. The removal efficiencies of $COD_{Mn}$ and $COD_{Cr}$ in ozone dose of 2mg/l - 6mg/l were about 40-50%. The removal efficiency of $NH_{3}-N$ was about 30-40% at pH8.5. In conclusion, it needs further systematic study and research concerned to treatability of $Fe^{2+},{\;}Mn^{2+}$ and biodegradability of organic compounds using Ozonation followed by biological filtration process in ground water treatment train.

• Magazine of the Korean Society of Agricultural Engineers
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• v.37 no.E
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• pp.63-71
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• 1995

Three types of land use were investigated to describe the effect of land use on both surface and ground water quality. Typical land uses of a grazing pasture, Sudan grass field and paddy in Kangwon province were selected and flumes and monitoring wells were installed. Land managements were carefully monitored, water samples were collected periodically and analyzed with respect to nitrate, TP and TKN at a laboratory of Kangwon Provincial Institute of Health and Environment from August, 1993 to May, 1994. Runoff from the pasture was formed mostly with seeping subsurface flow in the lower areas of the pasture. A few overland flows were observed during heavy storms, and when it occurred, runoff increased sharply. For the Sudan grass field, runoff was formed with overland flow. Nitrate concentration in runoff from both land uses seemed not affected by runoff and ranged from 0.241 to 4.137mg'/1. TP and TKN concentrations from the pasture were affected by overland flow. When overland flow occurred, TP and TKN concentrations abruptly increased to 5.726 and 12.841mg/1, respectively, from less than 1.0mg/l. However, these concentrations from the Sudan grass field were quite stable ranging from 0.191 to 0.674mg/l for TP and 0A70 and 1.650mg/l for TKN. Nitrate concentration was significantly affected by land use(Sudan grass field) and the concentration increase reached about 2mg/l per lOOm ground water flow. Nitrate concentration from a well located in the middle of rice fields also was significantly higher than that measured from a well located relatively undisturbed mountain toe area. TP and TKN concentrations in shallow ground water affected by the depth of the monitoring wells. The deeper the monitoring wells, the less TP and TKN concentrations were measured.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.3
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• pp.307-314
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• 2008

In this study, the effects of applied voltage, solution pH and coexistence of other ions such as sulfate ion (${SO_4}^{2-}$) and chloride ion ($Cl^-$) were investigated on the removal of nitrate-nitrogen ($NO_3{^-}-N$) from ground water by electrodialysis. The examined operating conditions were evaluated for optimizing the removal efficiency of $NO_3{^-}-N$. Real ground water samples taken from a rural area of Yongin city and artificial ones with components similar to the real ground water were tested for the study, which contained $NO_3{^-}-N$ concentration of 17mg/L that exceeds current drinking water quality standard of 10 mg/L. The increase in the removal rate of $NO_3{^-}-N$ was observed as the applied voltage increased from 5V to 30V, while no significant increase in the removal rate appeared at the applied voltage beyond 20V during a given operating time. The removal rate appeared to get lower at both acidic and basic condition, compared to neutral pH. Coexistence of of ${SO_4}^{2-}$and $Cl^-$ demanded much longer operating time to achieve a given removal rate or to meet a certain level of treated water concentration. When nitrate ion was combined with ${SO_4}^{2-}$and $Cl^-$, the removal rate was reduced by 4.29% and 10.83%, respectively.

• Journal of environmental and Sanitary engineering
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• v.19 no.1
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• pp.8-16
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• 2004

Ground water samples were collected from residential, green" industrial, landfill and mining area and analyzed for 23 inorganics from March to October in 2002. The results are as follows; 1. The detection frequencies of inorganic materials such as As, Ba, B, Mo, Ca, Mg, Al, Cu, Fe, Mn, Zn, Na, K were 7.2∼77.1% which showed that these inorganics were detected in many ground waters. 2. The detection frequencies of 7 inorganics(Cd, Cr, Ph, Se, Sb, Be, Tl) were commonly low at ranging from 0.42 to 2.5%. These inorganics were contained in ground water partially. 3. Three inorganics such as Hg, Ni, Ag were not detected in any ground-water samples. 4. Compared to the other areas, ground water samples from landfill area contained greater concentration in many inorgainics and then showed higher levels in industral, residential, mining and green area in order. 5. Compared to noted concentrations of bottled water, inorganic minerals including Ca, Mg, Na, K related to taste were fluent in target samples. The results showed that the average concentrations of Mg, Na, K were 4.0 mg/l, 14.7 mg/l, 1.5 mg/l respectively. 6. The concentrations of inorganics such as Sb, Ba, Mo, Be, Tl, K in some ground water samples exceeded the water quality standards of WHO, the US and UK. Especially, Ba, Mo, K also showed relatively high detection frequencies so these inorganics need to be considered as analytes in Korea Drinking Water Regulation in further study.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.09b
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• pp.1235-1236
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• 2005

• Journal of Environmental Health Sciences
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• v.21 no.1
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• pp.7-20
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• 1995

The aims of this study are to enhance the students' knowledge of the drinking water and its reliability by investigating drinking water situation on the drinking water. The results are as following 1. Status and drinking behavior about school drinking water (1) 97.82% of the schools are using the tap water as the resource of drinking water. (2) 46 schools are in possession of water tank and 18 schools of them are using the water tank as the resource of drinking water. The clearing and sanitization of the tank are carried out once in a year with hypochloronatrium by the low-level officials. (3) 51.28% of the schools are providing the students with drinking water and 75% of them with boiled water. The drinking water supply managers are low-level officials, nurse teachers, and dietitian. 2. Analysis of the drinking water quality (1) Most of the drinking water provided by the school are tap water 35.8%, barely tea 5.85%, filtered water 6.3%, ground water 1.1% and all turned out to be suitable for drinking. (2) The drinking water carried from home turned out to be unsuitable for drinking except pH criterion, especially the test of APC(Aerobic Plate Count) and Coliform group showed worse degree. These results were caused by the hygiene problem and maltreatment in water container.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.1B
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• pp.105-109
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• 2009

It is a well known fact that baseflow discharge of rainfall runoff impacts on water quality of surface water significantly. In this paper, impacts of nitrate discharged as base flow on stream water quality were studied by using a software, PULSE from USGS to calculate monthly ground water discharge from hydrograph. We used water quality and flow rate data for Ghapcehon2 site in Daejeon city for year 2005 as well as ground water quality data in the watershed acquired from government agencies. Agricultural and forestry land use are dominant for upstream of Ghapcheon2 in the watershed. Base flow contributes about 85~95% of stream flows during spring and fall while 25~38% of stream flow was induced by base flow during summer and winter. Monthly nitrate loading discharged as base flow for Ghapcheon2 was estimated by using averaged nitrate concentration of groundwater in the watershed. Nitrate loading induced by base flow at Ghapcheon2 was estimated as 5.4 ton of $NO_{3}{^-}-N/km^{2}$, which is about 60% of nitrate loading of surface water, 9.2 ton of $NO_{3}{^-}-N/km^{2}$. Seasonal variation of nitrate concentration of base flow was estimated by dividing monthly nitrate loading by monthly base flow discharge. Nitrate concentration of groundwater was increasing from rainy season. From this study, it can be understood that ground water quality monitoring is important for the proper manage of surface water quality.