• The Journal of Engineering Geology
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• v.12 no.4
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• pp.395-404
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• 2002

Contents of the specific components in the natural mineral water was discussed in relation to the well depth and geology. According to water quality data during the last five years(1998~2002), the nitrate and fluoride concentrations, and pH averaged 0.89~ 1.09 mg/L, 0.37~0.45 mg/L, and 7.30~7.59, respectively. These values are the similar range to those of generalized groundwater having same well depths, implying that shallow groundwaters flow into the production wells. In general, no clear relationships between the water quality, well depth, and geology were found. The average arsenic concentration of the natural mineral water increased from 0.0024 mg/L in 1999 to 0.0066 mg/L in 2002. The percentage of production well with arsenic level higher than 0.001 mg/L also increased from 20.1% in 1999 to 64.9% in 2002. In 2002, 11 out of 57 production wells exceed 0.001 mg/L which will be announced as a new arsenic standard for drinking water by USEPA.

• Journal of Korean Society on Water Environment
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• v.39 no.2
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• pp.153-161
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• 2023

The reservoir tank in an apartment is crucial for maintaining the quality of drinking water after it has undergone treatment. Investigating the water quality and potential contaminants in the reservoir tank is essential to ensure the safety of the drinking water. This study examined the water quality and precipitated suspended solids that accumulate at the bottom of the reservoir tanks in four apartments located in Gyeonggi province. As a result of the water quality investigation, turbidity increased proportionally to the distance from the water treatment plant (WTP) to the household. Heavy metals were also detected in the reservoir tank inlet but not in the water supplied from the WTP. The precipitated suspended solids (SS) in the reservoir tank contain high levels of heavy metals and total organic carbon (TOC). The precipitated SS mainly consists of Al, Mn, and Fe, which are expected to be a combination with turbidity-inducing substances. The X-ray diffraction (XRD) analysis revealed the presence of γ-FeO(OH), MnO₂, and β-Fe₂O₃ in the SS. Additionally, F-EEM analysis indicates that the dissolved organic matter in the SS is mainly derived from a natural water source and microorganism activities, including metal-oxidizing bacteria and biofilms that can absorb metal ions. Based on these findings, several countermeasures can be taken to prevent the inflow of SS into the household, including regularly cleaning the reservoir tank, replacing or cleaning old pipes in the water supply system, and implementing monitoring and filtering systems to manage the SS.

• Applied Microscopy
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• v.28 no.4
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• pp.551-561
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• 1998

The autometallographic method was used to demonstrate the localization of mercury deposits in spleen of mouse. The mercury deposits were identified with the light and electron mocroscope. Mice were treated with methylmercuric chloride in the drinking water (demineralized water) for 40 days. Control and mercury treated groups showed no significant differences in mean body weight and spleen weight per one mouse. Mercury grains were appeared in the germinal center of white pulp consist of a preponderancing lymphocytes, not in red pulp and capsule. At the ultrastructural level, mercury deposits were restricted to lysosomes of macrophage and lymphocyte. Specially, volume in lysosomes of the macrophage was increased. These results suggest that mercury localization in lysosomes is associated with the change of immune activity.

• Journal of Korean Society of Water and Wastewater
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• v.17 no.4
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• pp.534-541
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• 2003

Membrane processes are now frequently considered for application in drinking water treatment. The biggest impediment for applying membrane processes is fouling that comes from mass flux (such as particle and organic matter) to the membrane surface and its pores due to convection flow through the membrane. Natural organic matter (NOM) has been reported as the most detrimental foulant. Some research also indicated that particles were often the dominant cause of fouling. Therefore, both NOM and particle fouling need to be examined to better understand fouling in ultrafiltration. Two waters from natural sources, Lake Austin water and Missouri River water, were selected. Both waters are relatively hard waters but has significantly different particle concentrations, which will elucidate effects of particles on membrane fouling. Precipitative softening is traditionally designed to remove hardness ions in hard waters but it can also remove particles and organic matter. Therefore, the integrated water treatment with softening and ultrafiltration is proposed as a promising option for hard waters. The three levels of softening were used to represent different degrees of pretreatment to ultrafiltration in terms of organic matter (i.e., NOM fouling) and precipitates (i.e., particle fouling by further precipitation). Results showed that natural particles in Missouri River water was detrimental foulants of ultrafiltration. As the levels of softening were increased, NOM and particle removal was increased, and thus fouling was decreased. Direct images of the surface of the membranes by scanning electron microscopy allowed observation of the different properties of particles caught in fibril networks of natural organic matter.

• Environmental Engineering Research
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• v.22 no.3
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• pp.255-265
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• 2017

Polyelectrolytes are commonly used as flocculants in drinking water treatment. However the growing concerns about their toxicity have motivated the search for biocompatible flocculants. Here, we show that gelatin, a natural amphoteric polyelectrolyte, can be effectively adsorbed on clay surfaces and can potentially be a suitable substitute for existing flocculants. The adsorption of gelatin from its aqueous solution onto the mineral clay surfaces at different conditions was systematically investigated using the design of experiments methodology. The gelatin adsorption was found to vary considerately with pH variation showed a maximum adsorption at its isoelectric point. The amount of adsorbed gelation increased with increasing pH from 3 to 5, attained a maximum at pH 5 and then decreased with increasing pH from 5 to 11. Similarly, the amount of adsorbed gelatin showed decreasing trends around salt concentration of 0.05 M and temperature $35^{\circ}C$. On the other hand, the adsorption was continuously increased with time and polymer concentration in the range of 0.1-0.9 mg/dL. Finally, the jar tests confirmed the ability of gelatin for using a natural flocculant for water treatment.

• Journal of Ginseng Research
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• v.37 no.1
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• pp.64-73
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• 2013

Korean red ginseng water extract (KG-WE) has known beneficial effects on the cardiovascular system via inducting nitric oxide (NO) production in endothelium. Endothelial arginase inhibits the activity of endothelial nitric oxide synthase (eNOS) by substrate depletion, thereby reducing NO bioavailability and contributing to vascular diseases including hypertension, aging, and atherosclerosis. In the present study, we demonstrate that KG-WE inhibits arginase activity and negatively regulates NO production and reactive oxygen species generation in endothelium. This is associated with increased dimerization of eNOS without affecting the protein expression levels of either arginase or eNOS. In a vascular tension assay, when aortas isolated from wild type mice were incubated with KG-WE, NO-dependent enhanced vasorelaxation was observed. Furthermore, KG-WE administered via by drinking water to atherogenic model mice being fed high cholesterol diet improved impaired vascular function. Taken together, these results suggest that KG-WE may exert vasoprotective effects through augmentation of NO signaling by inhibiting arginase. Therefore, KG-WE may be useful in the treatment of vascular diseases derived from endothelial dysfunction, such as atherosclerosis.

• Journal of the Korean Society of Food Culture
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• v.19 no.1
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• pp.52-60
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• 2004

This study was performed to investigate the effect of Lycii fructus beer on serum lipid profiles and antioxidant activity in rat Sprague-Dawley (SD) rats weighting about 190g were divided into the following 5 groups ; distillate water (Control), 5% ethanol in distillate water (Ethanol), commercial beer (CB), Lycii fructus beer (LFB) and 5% alcohol red wine diluted with distillate water (RW). Body weight, total food intake, FER and percent organ (liver, kidney) weight per body weight were not significantly changed by Lycii fructus beer drinking. After 6 weeks, serum total cholesterol, triglyceride and HDL cholesterol level were not significantly different. But, Lycii fructus beer intake tended to decrease serum triglyceride level and atherogenic index. Also, GOT and GPT levels were expressed lower than Ethanol group. There was not significantly different in hepatic glutatiione (GSH) content and glutathione-S-transferase (GST) activities among 5 groups. Lipid peroxidation in the hepatic was decreased by Lycii fructus beer intake. The results demonstrated that Lycii fructus beer was potential and effective antioxidant that can protect the decrease associated with alcohol.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.09a
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• pp.519-519
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• 2003

We performed a hydrochemical study on a total of 89 bedrock groundwaters collected from preexisting wells (30 to 300 m deep) in the Boeun area. Hydrochemical data showed significant variations in the area, due to varying degrees of anthropogenic pollution. The waters were mostly enriched in Ca and HCO$_3$ but locally contained significant concentrations of anthropogenic constituents in the general order of Cl >NO$_3$>SO$_4$. In particular, about 11% of the examined wells exceeded the drinking water standard with respect to nitrate. We consider that aquifers in the area are locally highly susceptible to the contamination related to agricultural activities. Diagrams showing the relationships between the summation of cations (∑cations) and the concentration of several anions with different origin (natural versus anthropogenic) were used to estimate the relative role of anthropogenic contamination. A good correlation was observed for the relationship between ∑cations and bicarbonate, indicating that water-rock interaction (namely, hydrolysis of silicate minerals) is most important to control the water quality. Thus, we made an assumption that the equivalent of dissolved cations for a water should be equal to the alkalinity, if the chemistry were controlled solely by a set of natural weathering reactions. If we excluded the equivalent quantities of cations and bicarbonate (natural origin) from the acquired data for each sample, the remainder therefore could be considered to reflect the degree of anthropogenic contamination. Finally, we performed a multiple regression approach for hydrochemical data using the ∑cations as a dependent variable and the concentration data of each anion (natural or anthropogenic) as an independent variable. Using this approach, we could estimate the relative roles of anthropogenic and natural processes. Rather than the conventional evaluation scheme based on water quality criteria, this approach will be more useful and reasonable for the evaluation of groundwater quality in a specific region and also can be used for planning appropriate protection and remedial actions.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.2
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• pp.201-212
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• 2011

Nanotechnology is the applied science which develops new materials and systems sized within 1 to 100 nanometer, and improves their physical, chemical, and biological characteristics by manipulating on an atomic and molecular scale. This nanotechnology has been applied to wide spectrum of industries resulting in production of various nanoparticles. It is expected that more nanoparticles will be generated and enter to natural water bodies, imposing great threat to potable water resources. However their toxicity and treatment options have not been throughly investigated, despite the significant growth of nanotechnology-based industries. The objective of this study is to provide fundamental information for the management of nanoparticles in water supply systems through extensive literature survey. More specifically, two types of nanoparticles are selected to be a potential problem for drinking water treatment. They are carbon nanoparticles such as carbon nanotube and fullerene, and metal nanoparticles including silver, gold, silica and titanium oxide. In this study, basic characteristics and toxicity of these nanoparticles were first investigated systematically. Their monitoring techniques and treatment efficiencies in conventional water treatment plants were also studied to examine our capability to mitigate the risk associated with nanoparticles. This study suggests that the technologies monitoring nanopartilces need to be greatly improved in water supply systems, and more advanced water treatment processes should be adopted for better control of these nanoparticles.

• The Journal of Natural Sciences
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• v.8 no.1
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• pp.87-92
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• 1995

In the Vicinity of the Sindae-dong waste disposal site in Taejon, the average Cu, pb and Zn concentrations in soils are higher than those in other Korean soils but these are not high enough to cause any harmful effect to human and animal through the crop plants. Copper, Pb and Zn are not detected in the groundwater samples and F, Cl, $NO_2$, $NO_3$ and $SO_4$ concentrations in groundwater samples are lower than drinking water standards. However, the pH of groundwater sample in site D is 5.58 which is not suitable for the drinking water. With the electric resistivity method, the water-containg layers are found in contaminated soils and the resistivity values are considerably low because of the dispersion of plume by the leak of leachates. According to the results from the magnetic survey method, the anomalous values of the total geomagnetic fields and their gradients are found in the sampling site of low resistivity and high trace element concentrations.