• Membrane and Water Treatment
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• v.7 no.4
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• pp.277-296
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• 2016

The aim of this research was to investigate the ability of nanofiltration (NF) and ultrafiltration (UF) membranes as a filtration unit for groundwater treatment for drinking water resources. Commercial membranes denoted as TS40, TFC-SR3 and GHSP were used to study the performance based on rejections and fluxes. The investigation has been conducted using natural groundwater obtained from a deep tube well with initial concentration of iron (Fe) and manganese (Mn) at 7.15 mg/L and 0.87 mg/L, respectively. Experimental results showed that NF membranes exhibited higher fluxes than UF membrane with pure water permeability at 4.68, 3.99 and $3.15L.m^{-2}.h^{-1}.bar^{-1}$, respectively. For metal rejection, these membranes have performed higher removal on Fe with TS40, TFC-SR3 and GHSP membranes having more than 82%, 92% and 86% respectively. Whereas, removal on Mn only achieved up to 60%, 80% and 30%, for TS40, TFC-SR3 and GHSP membranes respectively. In order to achieve drinking water standard, the membranes were efficient in removing Fe ion at 1 and 2 bar in contrast with Mn ion at 4 and 5 bar. Higher rejection of Fe and Mn were achieved when pH of feed solution was increased to more than 7 as TFC-SR3 membrane was negatively charged in basic solution. This effect could be attributed to the electrostatic effect interaction between membrane material and rejected ions. In conclusion, this study proved that NF membrane especially the TFC-SR3 membrane successfully treated local groundwater sources for public drinking water supply in line with the WHO standard.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.09a
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• pp.369-372
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• 2004

This study presents the hydrogeochmical investigation to know the effect of geology and sources for water quality in small potable water supply system at rural area. The results of water quality in Geumsan area showed the 3.2% of water samples exceeded the limit of drinking water standard by bacteria. The hydrochemical investigation results indicated the high EC, Ca and HCO$_3$ in surface water and metasedimentary rocks and this is caused by the dissolution of calc-slicate minerals of metasedimentary rocks.

• Journal of Soil and Groundwater Environment
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• v.16 no.2
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• pp.1-5
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• 2011

We surveyed the citizens opinion about springs in Seoul for two years from 2008 to 2009. It was found that spring water was mostly used by citizens older than 50, and that 29.5% of citizens used purified tap water as drinking water, 27.2% of them used boiled tap water, 21.1% of them used spring water, and 12.1% of them used bottled water. Citizens who store spring water more than a day are 76.7%. Although many citizens (70.3%) knew that water quality had been tested, 40% of them didn't care about checking the certificate of water quality analysis. Once recognized that the spring water was unfit for drinking exceeded standard of drinking water, 85% of citizens would rather not use the spring water.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.9
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• pp.630-635
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• 2013

There is a need to establish systematic procedure of groundwater quality standards, however, there were no specified basis for establishing substances and values in Korean groundwater quality standards for non-drinking water. In this study, we reviewed basis for deriving groundwater quality standard in the developed countries, considering carcinogenic and non-carciongenic risk via inhalation and dermal contact exposure pathways. Also, we reviewed the prior systematic procedure of standards related to water quality (e.g. drinking water, surface water, and wastewater). USEPA RAGS, ASTM RBCA, and Massachusettes presented the formulas for deriving groundwater concentrations of chemicals and there were similarity and differences. We suggests systematic procedure of groundwater quality standards, as follows. (1) Selection of groundwater pollutants population, (2) Possibility of risk assessment, (3) Selection of monitoring priority substances, (4) Monitoring, (5) Risk assessment, (6) Selection of groundwater quality standard candidates, (7) Selection of new substances and values for groundwater quality standards. Especially, groundwater concentration of hazardous material were presented according to revised risk formulas via inhalation and dermal contact.

• Economic and Environmental Geology
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• v.29 no.1
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• pp.21-24
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• 1996

Inductively coupled plasma atomic emission spectrophotometer (ICP/AES) is a versatile modern instruments for the multi-element analysis, but quantitative analysis using ICP/AES with normal pneumatic nebulizer is not applicable for the measurement of elemental concentrations in water down to the drinkining water standard level except a few elements because of poor detection limits. However, the detection limit can be lowered enough to measure drinking water standard, if ultrasonic nebulizer and/or hydride vapor generator is attached. This method is tested with groundwater samples from Tajeon area. It is confirmed that the elemental concentrations in these samples are within the limit of drinking water standard for the most elements. However, uranium concentration is very high in some samples compared with the concentrations suggested by Environmental Protection Agency of U.S.A. There is no standard concentration level to this element in Korea and it should be prepared immediately.

• Journal of the Korean earth science society
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• v.42 no.5
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• pp.556-570
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• 2021

This study presents the data analysis results of groundwater chemistry and the occurrence of fluoride in groundwater obtained from the groundwater quality monitoring network of Korea. The groundwater data were collected from the National Groundwater Information Center and censored for erratic values and charge balance (±10%). From the geochemical graphs and various ionic ratios, it was observed that the Ca-HCO₃ type was predominant in Korean groundwater. In addition, water-rock interaction was identified as a key chemical process controlling groundwater chemistry, while precipitation and evaporation were found to be less important. According to a non-parametric trend test, at p=0.05, the concentration of fluoride in groundwater did not increase significantly and only 4.3% of the total groundwater exceeded the Korean drinking water standard of 1.5 mg/L. However, student t-tests revealed that the fluoride concentrations were closely associated with the lithologies of tuff, granite porphyry, and metamorphic rocks showing distinctively high levels. This study enhances our understanding of groundwater chemical composition and major controlling factors of fluoride occurrence and distribution in Korean groundwater.

• Journal of Korean Society on Water Environment
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• v.28 no.5
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• pp.754-761
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• 2012

Several drinking water treatment plants (DWTPs) produce the bottled tap waters (BTWs) as pilot production and provide them for noncommercial use. In 2008, acetaldehyde and chloral hydrate were detected in some BTWs and the public worry over the safety of the water. In this study, the BTWs produced from 7 DWTPs were tested for 13 chemicals including disinfection byproducts (DBPs). The level of four trihalomethanes (THMs) were increased up to 15 days. The average concentration of them was 0.0075 mg/L at the time of bottling and it was increased to 0.0214 mg/L after 15 days. The average acetaldehyde concentration was 0.0406 mg/L at the time of bottling but it was went up to 0.2251 mg/L after 11 days and then decreased. Although the initial concentrations of DBPs were below the drinking water standard, we also traced them at different storage conditions. Temperature affected the formations of THMs and acetaldehyde concentrations significantly. While the average concentration of THMs ranged from 0.0113 to 0.0182 mg/L at $25^{\circ}C$, it was increased to 0.0132 ~ 0.0256 mg/L at $50^{\circ}C$. In case of acetaldehyde, concentration ranged from 0.0901 to 0.2251 mg/L at $25^{\circ}C$, it was increased to 0.3394 ~ 1.0591 mg/L at $50^{\circ}C$. Throughout the tests with 7 BTWs samples, none of the chemicals was exceeded the drinking water standard of Korea. Therefore, it is recommended to avoid the exposure of BTWs to sunlight or high temperature during distribution and storage.

• Journal of Soil and Groundwater Environment
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• v.15 no.6
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• pp.99-106
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• 2010

We investigated springs in Seoul in 2009 to know the change of water quality according to storage method of spring water, the concentration of chemical compounds and their correlation. Even spring water that originally satisfied national standard for drinking water could be exceeded national standard for drinking water by storage method such as storage bottle, temperature and period; especially used PET bottles could affect the increase of total colony counts. Therefore, spring water is desirable to be consumed on the spot, or to be stored in sterilized bottles in refrigerator rather than room temperature at home, and also to be consumed shortly not exceeding 24 hours. Total colony counts, coliform, yersinia, $F^-$, $Cl^-$, $NO_3^--N$, hardness, total Solids, pH, color and Al were exceeded national standard for drinking water at some springs. The result of correlation analysis shows that hardness and total solids, which are caused by several ionic compounds, had relatively high correlations with other chemical compounds.

• Journal of the Korean Society of Groundwater Environment
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• v.6 no.1
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• pp.8-13
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• 1999

This research was investigated to examine the status of goundwater contamination in Chung-Nam area over 2 years from 1996 May to 1998 May. The results show that the overall detection rates of VOCs (volatile organic compounds) by region were as followed: industrial region > agricultural & industrial complex region > gas station region > around industrial region > downtown region, and excess rates of those were as followed: industrial region > gas station region > agricultural & industrial region > around industrial region > downtown region. Benzene and TCE of VOCs examined in Chon-An industrial region exceeded drinking water standard. At the agricultural & industrial complex region, the observed mean concentration of TCE was 3.107 mg/L and TCE was also detected at 48.152 mg/L which is 100 times higher than drinking water standard, and other VOCs were also observed at higher concentrations as well. Based on our studies, It is concluded that appropriate remedial action should be performed to protect further groundwater contamination and to restore groundwater quality in Chung-Nam area.

• Journal of the Korean GEO-environmental Society
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• v.2 no.3
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• pp.37-45
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• 2001

The characteristics of drinking groundwater quality was analyzed by investigating observed data during 1995-1997 in Daejeon city. As the analysis of observed data, the 30.1% of them were over the drinking water quality standards in Daejeon city and the unfit ratios of each region were 36.4% at Dong-Gu, 32.3% Daedeog-Gu, 31.2% Jung-Gu, 30.0% Seo-Gu and 25.2% at Yusoung-Gu. It was found that the items over the drinking water quality standards were 24 items and all of the mean concentration of water quality items were under the drinking water quality standard except Fe and Mn in 1997. The mean concentration of Fe was $1.31mg/{\ell}$ over the water quality at Daedeog-Gu and that of Mn was $0.53mg/{\ell}$ at Jung-Gu. The concentrations of $NH_3$-N, Mn, Fe, Al and F were increased rapidly in 1997, so that the cause of increasing also must be examined closely. It was found that the rainfall and unfit ratio(unfit frequency/test frequency) of E-coli and bacteria had the hydrologic persistance. The coefficient of correlation between them was 0.525. On the rainfall over 100mm, it was 0.673 and on the rainfall over 150mm, it was 0.641. The correlation between E-coli and rainfall was higher than that between bacteria and rainfall.