• Journal of Korea Water Resources Association
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• v.41 no.11
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• pp.1143-1152
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• 2008

Korea is located in a monson area, so that 2/3 of precipitation is fallen down in rainy season and dry season has few rainfall. Also, water quality gets worse during dry season by shortage of water. In this paper, the method, which is a physical way to improve water quality by dilution through over supplied water from big reservoir or dam, is analyzed at Han-river basin. For the sake of the analysis, the basin is divided in 33 catchments and each catchments' natural flow is simulated by SWAT-K and the future water demand is estimated by using statistics data. It is considered that Han-river basin has two big reservoirs(Chung-ju dam, So-yang gang dam) and potential discharge by dam is calculated through case of supply water from each dam and supply water from both dams.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.2 no.4
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• pp.47-53
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• 1999

In order to elucidate physiological factors involved in causing the winter injuries of evergreen Japanese rhododendron (Rhododendron obtusum cv. Hinodegiri) and semi-evergreen rhododendron (Rhododendron yedoense var. poukhanense), these studies were conducted from late winter to early spring. The results were summarized as follows; The water potential, water content in stem, water potential and content have continuously increased in both species between February and May. In R. yedoense, shading treatment had 0.3MPa upper water potential and 3% upper water content than the control. Rhododendron obtusum, the treatments with shading had 0.9MPa upper water potential and 11% upper water content that the control. The difference of water balance by treatments could be found in vitality of stem measured by TTC test. Especially R. obtusum in the treatments with shading in has higher vitality than the control. we find that winter damage of evergreen R. obtusum was determined by whether water balance could be recovered from water deficient state during the dehardening period, or not. In order to recover of the water balance, decreasing water loss more important than increasing water supply, and that was effectively acrueved by the treatment with shading.

• Journal of Korean Society of Water and Wastewater
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• v.26 no.4
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• pp.591-598
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• 2012

Denitrification is an important biological mechanism in wastewater treatment process because this process is technically to remove nitrogen from water to air. There have been lots of study about denitrification engineering and molecular biological research about denitrifying bacteria, respectively. However, combination of these researches was unusual and rare. This study is about the correlation between quantity of denitrifying bacteria and denitrification potential, and consists of NUR batch test as analysis method of denitrification potential and quantitative molecular analysis for denitrifying bacteria. Three reactors (A/O, MLE and A/O of nitrogen deficiency) are operated to get activated sludge with various denitrification potential. All samples which were acquired from reactors were measured denitrification potential by NUR test and NUiR test. Also, Real-time PCR was conducted for quantification of denitrifying bacteria composition in activated sludge. The various denitrification potentials were measured in the reactors. The denitrifiaction potential was the highest in MLE process and the reactor of the nitrogen deficiency showed the lowest. Genomic DNA of activated sludge was obtained and consequently, real-time PCRuse the primer sets of nirK and nirS　were conducted to quantify genes involving denitrification reductase production. As the result of real-time PCR, nirK gene showed more significant influence on denitrification potential comapred with nirS gene.

• Proceedings of the Korea Water Resources Association Conference
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• 1994.02a
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• pp.331-336
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• 1994

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2000.05a
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• pp.115-121
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• 2000

As the development of industry water quality of river is going to bad because of waste water of an industrial complex and general home agricultural chemicals exhaust of $SO_3$ and CO gas acid rain and so on. Corrosion damage of boiler factory equipment and so forth occur quickly due to using of the polluted water resulting in increasing leak accident. Especially working life of hot water boiler using the polluted water becomes more short and energy loss increases. The cathodic protection method is the most economical and reliable one to prevent corrosion damage of steel structures. Mg-base alloys galvanic anode protection of cathodic protection method is suitable for than application of hot water boiler using water with high specific resistance such as tap water. This paper is studied on the cathodic protection characteristics of how water boiler. In tap water and 0.001mol/$\ell$ NaCl solution the characteristics of anodic polarization of Mg-base alloys galvanic anode and tube material is investigated the measurement of cathodic protection potential according to the time elaspsed is carried out.

• Journal of Korean Society of Water and Wastewater
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• v.21 no.1
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• pp.37-46
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• 2007

A feasibility test was conducted to evaluate the addition of turbidity substance in a coagulation process to remove natural organic matters (NOM), the precursor of disinfection by-products (DBPs). The experimental water sources were synthetic water containing 5 mg/L of humic acid and 50 mg/L of NaHCO3 and drinking water resource of Ulsan city (S Dam water, D Dam water and Nak-Dong raw water). The examined turbidity substances were kaolin, acid clay, and modified clay (0.38 meq $NH_4{^+}-N/g$ clay). In Jar tests at different concentrations of the turbidity substances (5, 10, 15, 20, 30 mg/L) using the synthetic water, the turbidity substances improved the removal of turbidity, UV-254 absorbance and dissolved organic carbon (DOC) by 23.8-38.1%, 17.0-24.5% and 2.5-44.5%, respectively. The modified clay showed higher removal efficiencies than other substances. In Jar tests using the drinking water, 10 and 20 mg/L of modified clay enhanced the removal efficiencies of turbidity, UV-254 absorbance, DOC, trihalomethane formation potential (THMFP), and haloacetic acid formation potential (HAAFP) by 3.0~4.3%, 19.1~29.0%, 12~34.9%, 4.9~36.7%, and 1.6~30.2%, respectively.

• Journal of the Korea Convergence Society
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• v.12 no.5
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• pp.185-190
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• 2021

An electrolyzed-acidic water treatment was investigated as a methods for removing ammonia, which is a cause of odor in life environment. The prepared electrolyzed-acidic water was found out as stable solvent capable of neutralizing weak alkaline ammonia by measuring changes in pH and ORP. It was found out that ammonia was removed from the mixture solution of electrolyzed-acidic water and ammonia water by the UV-vis absorbance analysis and electrochemical open-circuit potential measurement. The neutralized ammonia by electrolyzed-acidic water and effectively removed odor was measured using ammonia gas detecter. Consequently, we recommend the electrolyzed-acidic water can effectively and safely remove ammonia in eco-friendly.

• Korean Journal of Soil Science and Fertilizer
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• v.12 no.2
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• pp.77-82
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• 1979

Wilting and transpiration charactistics of Panax ginseng leaves were investigated at two temperature levels. Water potential and water absorption characteristics of leaf segments were also observed. Soybean leaves were compared. 1. Ginseng leaves were thiner, higher in water content and lower in dehydration rate. But time required to reach permanent wilting point (pwp) was less than half of that of soybean leaves because water content at pwp was about two times higher (80% of initial water for ginseng and 50% for soybean leaves). The time was shorter under high air temperature. 2. Transpiration rate was about a quater of soybean leaves and lower at $33^{\circ}C$ than $23^{\circ}C$, indicating that ginseng leaves are less tolorant to high air temperature. 3. Ginseng leaf segment showed smaller water free space but greater water deficit and little difference in was absorption rate. 4. Water potential of leaves measured by liquid immersion method was lower than that of soybean leaves. 5. Above results strongly suggest that ginseng plants are more susceptible to water stress. Thus greater light intensity during leaf growing stage (April to June) is recommendable to increase stomate frequency resulting greater transpiration rate and high temperature tolerance during July and August. Abundant water around roots seems to be beneficial as long as oxygen is not limited in rhizosphere.

• Proceedings of the Korea Water Resources Association Conference
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• 1996.02a
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• pp.401-448
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• 1996

• ALGAE
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• v.18 no.2
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• pp.157-167
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• 2003

Effect of the effluent of the sewage and wastewater plants on the algal growth was investigated from the 19 plants located in the Nakdong river basin. Most of the samples showed high values of the algal growth potential (AGP) when they were mixed with natural river water at 20% of final concentration. At 20% of the mixing ratio, the mixed effluents of sewage and wastewater showed 3.5 and 1.8 times higher AGP than those of the natural river water. The higher AGP values are attributable to the high contents of phosphorus and ammonium in the effluent. The mixing ratio of effluents of the discharge/river flow was highest in the Kumho River (42.8%) followed by the middle of Nakdong River (22.7%), Kam Stream (13.9%), Byungsung Stream (13.3%), Yangsan Stream (7.9%), and Young River (5.4%). Comparison of the trophic state of the effluents with natural river water indicated that the effluents showed higher trophic values than natural water. Concentrations of total phosphorus, total nitrogen and conductivity in the effluents were 12.3, 4.9 and 5.3 times higher than the those found in natural river water respectively. The AGP values were highly related with the trophicity of the water especially on the concentrations of phosphate and ammonium. Toxicities of the treated sewage water, wastewater and livestock waste water tested by the luminescent bacteria, Vibrio fischerii were generally low.