• Journal of the Korean Society of Groundwater Environment
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• v.5 no.4
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• pp.203-209
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• 1998

The quality of groundwater used for natural mineral water should be strictly regulated on international level by hydrogeology experts and officials because groundwater is greatly subjected to contaminations and its aquifer system may be easily destroyed by external reasons. A total of 18 natural mineral water plants exist in Precambrian metamorphic terrains of the Gyunggi massif and Yeungam massif. The g개undwater quality for the natural mineral water investigated in hydrochemical aspects shows that pH ranges from 6.85 to 8.02 with an average of 7.52. The electric conductivity (EC) and hardness average 134.1 $\mu$S/cm and 43.5, respectively, which are relatively low to the total average (151.4 $\mu$S/cm and 57.9). The contents of major cations and anions are in the order of $Ca^{2＋}$＞$Na^{＋}$＞Mg$^{2＋}$＞K$^{＋}$ and HCO$_3$$^{-}$ ＞SO$_4$$^{2－}$ ＞Cl$^{-}$ ＞F$^{-}$ , respectively. The dominant water types determined by Piper diagram are $Ca^{2＋}$－$Na^{＋}$－HCO$^{-}$ $_3$and $Ca^{2＋}$-HCO$^{-}$ $_3$, mainly due to the dissolution of plagioclase in the host rocks. Representative correlation coefficients between chemical species are $Ca^{2＋}$－HCO$^{-}$ $_3$(0.92), $Ca^{2＋}$－Cl$^{-}$ (0.63), $Na^{＋}$－F$^{-}$ (0.67), HCO$^{-}$ $_3$－Cl$^{-}$ (0.66), and $Na^{＋}$－HCO$^{-}$ $_3$(0.63). The determinative. coefficients between $Ca^{2＋}$ and HCO$^{-}$ $_3$, and (Ca$^{2＋}$＋$Na^{＋}$＋K$^{＋}$ and EC art highest among the elements. According to the saturation index, most chemical species are undersaturated with respect to major minerals, except for some silica phases. In viewpoint of phase equilibrium, the chemical evolution of the groundwater may continue to proceed with increasing pH because the groundwater is undersaturated with respect to feldspars.

• Journal of Soil and Groundwater Environment
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• v.20 no.4
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• pp.31-40
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• 2015

Various types of inorganic and organic colloids are present in natural water including groundwater. Previous studies showed that Fe, Mn and Al are colloid-forming elements and dissolved concentrations can be erroneous for these elements if water samples are not properly filtered. Dissolved concentrations of elements including Ca, Na, Mg, K, Fe, Mn, Si and Al in groundwater from alluvial and bedrock aquifers, and surface water near Nakdong River were determined to evaluate effects of colloids on dissolved concentrations in natural water samples using various pore sizes of filters. Groundwater is mostly anoxic and have elevated concentrations of Fe and Mn, which provides a unique opportunity to observe the effects of colloids on dissolved concentrations of colloid-forming elements. Membrane filters with four kinds of pore sizes of 1000 nm, 450 nm, 100 nm, and 15 nm were used for filtration of water samples. Concentrations of dissolved concentrations in each filtrate did not show significant differences from 1000 nm to 100 nm. However, concentrations of all elements considered were decreased in the filtrates obtained using 15 nm pore size filters by 10 to 15% compared to those using 450 nm except for bedrock groundwater. Al in surface water showed a distinct linear decrease with the decrease of filter pore sizes. These results showed that 100 nm pore size had little effect to remove colloidal particles in alluvial groundwater and surface water in our study. In contrast, significant concentration decreases in 15 nm pore size filtrates indicate that the presence of 15 to 100 nm colloidal particles may affect determination of dissolved concentrations of elements in natural water.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.2
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• pp.129-133
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• 1999

Excessive soil water at vegetative growth stages during the rainy season induces yield losses in soybeans. Our objectives were to obtain basic information about the cultivar differences and to understand the stress-tolerance process for due to excessive soil water. Previous experiments revealed soybean genotypic differences in tolerance to excessive soil water. A field experiment was conducted at the Research Farm of Korea University near Seoul on 21 May 1998. Soybean[Glycine max (L.) Merrill] cultivars, 'Hannamkong' (sensitive) and 'Taekwan-gkong'(tolerant) were planted in vinyl-lined plots(1.2 x 4.2 x 0.3 m deep) and control plots. Drip irrigation began at VI growth stage to submerge the soil surface. Three weeks of excessive soil water treatment reduced all growth parameters measured to soybean plants. Excessive soil water stress resulted in decreases of N, P, K, Ca, Mg and Cu, and increases of Fe and Mn contents in soybean leaves. The stress index of tolerant cultivars under excessive soil water showed no large difference in soybean growth characteristics measured at three growth stages. However, K, Ca, Mg, Fe and Mn contents in soybean leaves appeared to differ between sensitive and tolerant cultivars. From the above results, stress and tolerance indices are proposed for a method to test cultivar differences in plant responses within a species under adverse growth environments.

• Journal of Korea Water Resources Association
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• v.53 no.spc1
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• pp.827-832
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• 2020

The catchment management experiences of the Evian natural mineral water (NMW) bottling company were reviewed. Evian is among the leading brands of bottled NMW in France, exporting worldwide and becoming a role model for companies in many countries due to its long-term experiences in sustainably managing NMW source areas. Experiences of bottled water companies in France show that they are incessantly moving forward with proactive and advanced ideas to meet environmental challenges. For business sustainability, companies are dedicated to improving their environmental performance through effective and planned resource management. Evian has been working with the local community in a spirit of co-ownership to invent and preserve the water resource and fulfill its ambition of sustainable industrial functioning. The partnership aims to balance the protection of the NMW resource and sustainable agricultural development within the catchment.

• Journal of environmental and Sanitary engineering
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• v.22 no.3
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• pp.35-50
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• 2007

In order to investigate water pollution of spring, we carried out the experiments on mineral water, rainwater and surrounding soil of several springs collected in Incheon area from February to August in 2007. The results were as follows. 1. Soil : This study investigated the pH and organic matter contents in the soil which effect on microorganisms. The pH value was from 4.5 to 5.3 on average and organic matter contents ranged from 1.09% to 5.6% and E. coli, K. pneumoniae, S. faecalis and other microorganisms were isolated. 2. Natural mineral water : As the rainfall increased, the concentration of $No_3-N$, consumption of $KMnO_4$ and the number of microorganisms was increased while the other physicochemical items were not affected. The microorganism isolated in the natural mineral water were as follows: E. coli, K. oxytoca S. faecalis, S. facium, and so on from evacuation; E. agglomerans, E. amnigenus, E. cloacae, E. sakazakii and so on from the environments and evacuation. Detection of these microorganisms shows that the environment around the spring had been exposed to excrements of the warm blood animal. 3. Rain : The coliforms in the rain were the identical one detected from the mineral water and the soil. In conclusion the quality of natural mineral water is influenced by rain, resident bacteria of soil and surrounding environment. This study will be the basic data of characteristics of spring in Incheon area and also this result will give useful aids for the efficient control of spring.

• Journal of Energy Engineering
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• v.27 no.2
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• pp.70-80
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• 2018

Natural organic matter (NOM) is among the most common pollutant in underground and surface waters. It comprises of humic substances which contains anionic macromolecules such as aliphatic and aromatic compounds of a wide range of molecular weights along with carboxylic, phenolic functional groups. Although the concentration of NOM in potable water usually lies in the range of 1-10 ppm. Conventional treatment technologies are facing challenge in removing NOM effectively. The main issues are concentrated to low efficiency, membrane fouling, and harmful by-product formation. Ion-exchangers can be considered as an efficient and economic pretreatment technology for the removal of NOM. It not only consumes less time for pretreatment but also resist formation of trihalomethanes (THMs), an unwanted harmful by-product. This article provides a comprehensive review of ion exchange processes for the removal of NOM.

• Analytical Science and Technology
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• v.8 no.4
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• pp.759-770
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• 1995

By extensive studies with the quantitative status of the mineral constituents of thousands of water samples, it was found that almost in all natural waters irrespective of the surface or sub-surface sources, minimum 99.5% of the total amount of the cationic constituents are generally the contributions of 3 commonly present parameters viz. Ca, Mg and Na and that of the anionic species are same and contributed by $HCO_3$, Cl and $SO_4$ only. In the field of water works, all these major mineral substances are conventionally measured as their individual ions. But till now, no reliable and generalised methods or rules have been developed for the determination of the exact kinds of the individual salt components and their amounts from these ionic constituents normally present in water. As salt content, only the TDS (Total Dissolved Solids) parameter is frequently measured by evaporation of the water sample. But TDS can tell nothing about the kinds and amounts of the individual salts present in it. Considering the analytical importance of the estimation of the mineral substances as their individual salts, some generalised mathematical models have been developed by this research which are based on the 'hypothetical order of chemical combinations' as may occur among the ionic constituents. With the help of these models, one can easily assume the most probable salts with approximate quantities derived from the ionic constituents. In addition, approximate amount of Na content can also be estimated mathematically with simultaneous verification of the correctness of the water analysis results. The models are stated in this paper with practical illustrations and descriptions of the method of applications.

• Economic and Environmental Geology
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• v.43 no.1
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• pp.33-42
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• 2010

The purpose of this study was to understand the degree of natural radon removal efficiency of small-scale water supply systems. Six sites were selected for this study, and data on well characteristics (depth, pumping rate, water tank capacity, distance from well to tap water) were obtained. Water samples both from raw water and three tap waters at each site were collected and analyzed for radon concentration. Average radon removal efficiency of the five sites (A-E) in Nov. 2006 was 26.0% while that of the same sites in Dec. 2006 was 45.6% indicating seasonal difference in natural radon removal efficiency. Meanwhile short-term (April 23, April 30, May 8, 2007) radon removal efficiency from the site F was 44.1-49.0%, implying only a little difference in natural radon removal efficiency. The degree of radon removal at tap water was influenced mainly by pumping rate rather than distance from the well and water tank capacity.

• Journal of Soil and Groundwater Environment
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• v.24 no.3
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• pp.24-35
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• 2019

It is known that ${\delta}^{13}C_{DIC}$ (carbon-13 isotope of dissolved inorganic carbonate (DIC) ions) of water increases when dissolved $CO_2$ degases. However, ${\delta}^{13}C_{DIC}$ could decrease when the pH of water is lower than 5.5 at the early stage of degassing. Laboratory experiments were performed to observe the changes of ${\delta}^{13}C_{DIC}$ as $CO_2$ degassed from three different artificial $CO_2$-rich waters (ACWs) in which the initial pH was 4.9, 5.4, and 6.4, respectively. The pH, alkalinity and ${\delta}^{13}C_{DIC}$ were measured until 240 hours after degassing began and those data were compared with kinetic isotope fractionation calculations. Furthermore, same experiment was conducted with the natural $CO_2$-rich water (pH 4.9) from Daepyeong, Sejong City. As a result of experiments, we could observe the decrease of DIC and increase of pH as the degassing progressed. ACW with an initial pH of 6.4, ${\delta}^{13}C_{DIC}$ kept increasing but, in cases where the initial pH was lower than 5.5, ${\delta}^{13}C_{DIC}$ decreased until 6 hours. After 6 hours ${\delta}^{13}C_{DIC}$ increased within all cases because the $CO_2$ degassing caused pH increase and subsequently the ratio of $HCO_3{^-}$ in solution. In the early stage of $CO_2$ degassing, the laboratory measurements were well matched with the calculations, but after about 48 hours, the experiment results were deviated from the calculations, probably due to the equilibrium interaction with the atmosphere and precipitation of carbonates. The result of this study may be not applicable to all natural environments because the pressure and $CO_2$ concentration in headspace of reaction vessels was not maintained constant as well as the temperature. Nevertheless, this study provides fundamental knowledge on the ${\delta}^{13}C_{DIC}$ evolution during $CO_2$ degassing, and therefore it can be utilized in the studies about carbonated water with low pH and the monitoring of geologic carbon sequestration.

• Journal of the Korean Society of Safety
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• v.16 no.1
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• pp.65-72
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• 2001

Portland cement concrete is made with coarse aggregate, fine aggregate, portland cement, water and, in some cases, selected chemical admixture such as air-entraining agents, water reducer, superplasticizer, and so on, and mineral admixture such as fly ash, silica fume, slags, etc. Typically, in the concrete, the coarse aggregate and fine aggregate will occupy approximately 80 percent of the total volume of the finished mixture. Therefore, the coarse and fine aggregates affect to the properties of the portland cement concrete. As the deposits of natural sands have slowly been depleted, it has become necessary and economical to produce crushed sand(manufactured fine aggregate). It is reported that crushed sand differs from natural sands in gradation, particle shape and texture, and that the content of micro fines in the crushed sand affect to the quality of the portland cement concrete. Therefore, the purpose of this paper is to investigate the characteristics of fresh and hardened concrete with higher micro fines. This study provides a firm data to apply crushed sand with higher micro fines.