• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.04a
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• pp.499-502
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• 2004

Groundwater chemistry in a coastal region having complex contaminant sources was investigated. Water analysis data for 197 groundwater samples collected from the uniformly distributed sixty-six wells were used. Chemical analysis rand results indicate that groundwaters show wide concentration ranges in major inorganic ions, reflecting complex hydrochemical processes of pollutants. Due to the complexity of groundwater chemistry, Results illustrate that thirty five percent of the wells do not fit for drinking based on nitrate and chloride concentration in the study area. the samples were classified into four groups based on Cl and NO$_3$ concentrations and the processes controlling water chemistry were evaluated based on the reaction stoichiometry. The results explained the importance of mineral weathering, anthropogenic activities (nitrification and oxidation of organic matters), and Cl-salt inputs (seawater, deicer, NaCl, etc.) on groundwater chemistry. It was revealed that mineral dissolution is the major process controlling the water chemistry of the low Cl and NO$_3$ group (Group 1). Groundwaters high in NO$_3$ (Groups 2 and 4) are acidic in nature, and their chemistry is largely influenced by nitrification, oxidation of organic matters and mineral dissolution. In the case of chloride rich waters (Group 3), groundwater chemistry is highly influenced by mineral weathering and seawater intrusion associated with cation-exchange reactions.

• Journal of the Korean Society of Groundwater Environment
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• v.5 no.3
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• pp.141-147
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• 1998

This study was initiated to identify the general groundwater quality and the effects of heavy-metal enrichments in the black shales and coal materials in Dukpyung area. Groundwater quality could be divided into three groups based on the major weathering processes in the groundwater system; Group I of carbonate weathering, Group II of silicate weathering with the probable effects of acidic mine drainage, and Group III of silicate weathering with relatively high concentrations of chloride components in anions. Metal contamination of groundwater was not observed. Locally, however, acidic mine drainage appeared to be produced and recharged into the groundwater system. In addition, contamination by NO$_3$-N ranged 2 to 3 times higher than the drinking water standards, probably due to infiltration of domestic sewage and/or fertilizers into the shallow aquifer.

• Journal of Soil and Groundwater Environment
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• v.25 no.4
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• pp.67-76
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• 2020

Polycyclic aromatic hydrocarbons (PAHs) are organic compounds that tend to persist in environmental media for a long period of time. This work presents a 2-year monitoring study of occurrence of three PAHs (benzo(a)pyrene, naphthalene, and fluoranthene) in groundwater. The groundwater samples were collected from 106 sites of nation's groundwater quality monitoring network and analyzed by simultaneous analysis method to quantify the concentrations of the PAHs. Benzo(a)pyrene was not detected in all samples. Naphthalene and fluoranthene concentrations ranged from not detected to 12.8 ng/L and not detected to 10.5 ng/L with their detection frequency being 57.8 and 4.2%, respectively. The concentrations of PAHs in ground- and drinking waters are not currently regulated in Korea, but the concentration levels of naphthalene and fluoranthene found in this work were lower than the regulatory limits of other countries (naphthalene 0.001~0.07 mg/L, fluoranthene 0.001~1.4 mg/L). The monitoring result of this study revealed that PAHs exist as trace amounts in domestic groundwater, however continuos monitoring is necessary to protect groundwater from PAHs contamination with growing industrialization and urbanization.

• Journal of Korean Society on Water Environment
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• v.26 no.1
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• pp.116-124
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• 2010

While groundwater is the major source for drinking and irrigation purposes, arsenic (As) contamination of groundwater is a serious issue in Bangladesh. With a view to reduce As contamination in drinking water the guideline value recommended for Bangladesh is 0.05 mg/L. We assessed groundwater As in an As-affected Sadar Upazilla (small administrative unit) in the District (administrative unit) of Chapai Nabwabganj during 2006, where 50% hand tube well water were above the recommended limit (0.05 mg/L) during dry season. Almost 20% tube well waters were above the recommended limit during rainy season, perhaps due to the dilution of water table. The groundwater in Bangladesh contaminates surface soils and plants thereby As entering the food chain. In 2005, we examined the As levels in different rice varieties grown in different Districts of Bangladesh and the As concentrations in rice grain ranged from 0.07~1.12 mg/kg while the concentrations in 3 rice varieties were above the recommended limit (1 mg/kg rice grain) and the maximum concentration was 1.12 mg/kg rice grain in the rice variety BR 11. With few exceptions, the As content of rice grain in Bangladesh is not considered to be concentration of greater health concern as yet. We also observed enhanced root uptake, efficient root-to shoot translocation, and a much elevated tolerance through internal detoxification all contribute to As hyperaccumulation in a plant, ladder brake fern (Pteris vittata L.). But the phytoremediation technique might not be an appropriate tool to reduce the As calamity in the vast areas of Bangladesh. To mitigate the As problem of Bangladesh, better coordination among governmental agencies and many other organizations will be required to combat the disaster.

• Journal of Appropriate Technology
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• v.6 no.2
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• pp.183-189
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• 2020

Developing countries are areas where many problems arise from poor drinking water infrastructure. Developing countries often use groundwater as their primary source of drinking water, which causes problems. Among them, coastal areas are easily exposed to saltwater intrusion due to their geographical characteristics. Groundwater in areas exposed to saltwater intrusion has higher salinity than usual. If you continue to consume high salinity groundwater can cause a variety of fatal effects on the human body. Therefore, various alternatives have been proposed. This study explores the applicability of CDI(Capacitive Deionization) and RO(Reverse Osmosis) for water purification systems in areas where saltwater intrusion has occurred. Therefore, we will evaluate this by conducting water purification experiment. On the other hand, the supply of electricity is also important in the operation of water purification facilities. However, in many areas of developing countries, electricity is often not available. Therefore, this study intends to calculate the power consumption required for the actual use of the filter and to include it in the evaluation.

• Korean Journal of Environmental Agriculture
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• v.12 no.3
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• pp.281-297
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• 1993

Nitrogen is an element required to meet optimal plant growth. However, when it was applied (as chemical fertilizer or animal waste) more than the demand of plant and managed it unreasonably can be accumulated in subsoil and leached from soil system. Nitrogen also can be act as an pollutant to soil and water through water contamination if its concentration exceed the critical level. The concentration and downward movement of nitrate in soil is influenced by cultural practices and soil properties. High level of nitrate nitrogen in drinking water is harzadrous for animal and human health, especially for infants and the restoration of the quality of groundwater is impossible by now. Therefore it is the only way to prevent from leaching of nitrate nitrogen to keep the quality of groundwater as vital water resource. The aims of the presentation of this review paper are to understand the relationship between agricultural practices and the concentration of nitrate nitrogen in groundwater and to suggest further informations for the rational management methods to reduce the leaching of nitrate nitrogen in soil.

• Journal of Soil and Groundwater Environment
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• v.25 no.4
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• pp.28-34
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• 2020

Nitrate released from chemical fertilizer, animal wastes, and synthetic detergents can cause methemoglobinemia to infants, thus the standard in drinking water is set to 10 mg/L as World Health Organization recommended. In this study, zero-valent iron-modified rice straw biochar was used to reduce and remove nitrate in the aqueous phase. The rice straw biochar was prepared by pyrolyzing the biomass at 700℃ for 3 hours, and the biochar was modified using 1 M Fe(III), and the Fe(III) on the biochar was reduced to zero-valent iron using sodium borohydride. The modified biochar removed nitrate effectively, which removed more than 91% of nitrate. For the synthetic groundwater, the nitrate removal was lowered to 82% due to the presence of other anions.

• Journal of Korean Society of Water and Wastewater
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• v.35 no.6
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• pp.497-505
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• 2021

This paper investigates the current status of Jeju special self-governing province (JSSGP)'s water infrastructure and recommends directions for improvement. JSSGP relies on groundwater for most of its water resources. Recently, water usage has been steadily increasing due to the increase of residents and tourists while the quality of groundwater has been steadily worsening. Deterioration in water quality of groundwater can be seen through the increase in concentration of nitrate nitrogen and microorganisms. To overcome such problems, water consumption must be reduced by water demand management in all fields including residential and agricultural water use. The quality of water resources should be preserved through the management of pollutants. For efficient management of water resources, great efforts should be made to reduce the leakage rates in household and agricultural water, which is currently at the highest level in the country. Furthermore, diversification of water intake sources other than groundwater is needed, especially for agricultural water supply. For water and sewerage facilities, compliance with drinking water quality standards and discharge water quality standards must be achieved through the optimization of operation management. This process requires recruiting professionals, improving existing workers' expertise, and improving facilities.

• Journal of Soil and Groundwater Environment
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• v.22 no.5
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• pp.71-81
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• 2017

The hydrogeochemical characteristics of groundwater in the small waterworks are examined with 81 groundwater samples in Ulju region, Ulsan. The pH ranged in 6.3-8.2 and did not exceed the drinking water standards. Electrical conductivity ranged from $50{\mu}S/cm$ to $1,719{\mu}S/cm$. It indicated that the electrical conductivities in groundwaters at the study area are relatively low, compared with other groundwaters in Ulsan area. The calcium concentrations in groundwaters ranged from 3.55 to 113.01 mg/L, and sodium concentrations ranged from 2.02 to 65.50 mg/L. Nitrate concentrations ranged from 0 to 100.56 mg/L and potassium concentrations ranged from N.D (not detected) to 2.50 mg/L. Major cations and anions were mainly derived from the water-rock interaction involving feldspar, gypsum and calcite. The groundwaters were mainly the $Ca-(Na)-HCO_3$ type, classified as the early stage of groundwater evolutions. The correlation between electrical conductivities and Ca concentrations in groundwaters was relatively high ($R^2=0.74$). In the correlations between ions, the correlation coefficient between $SO_4$ and Ca was 0.65 and between Mg and $HCO_3$ was 0.65.

• Economic and Environmental Geology
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• v.31 no.6
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• pp.485-498
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• 1998

The water-rock interaction and anthropogenic contamination affecting to geochemical composition of shallow and deep groundwaters were investigated in the agricultural area of Myunggok-ri, Kongju. The shallow groundwater is classified into the chemical types of $Ca-HCO_3$ and $Ca-Cl(SO_4)$ and shows weak acid having an average pH 6.2. Deep groundwater shows the uncontaminated composition of the chemical types of $Na-HCO_3$ and Na $(Ca)-HCO_3$ with pH of 8.4~8.8. The grouping approach of chemical data of waters shows the distinguished trend between water composition influenced anthrophogenic input and water composition mainly determined by natural process such as water-rock interaction. The main anthropogenic inputs affecting chemical composition of shallow groundwater are the contaminants such as $K^+$, $NO_3{^-}$, $Cl^-$ having average values of 4.4 mg/l, 22 mg/l, 13.7 mg/l, respectively. The contaminants were probably derived from fertilizer, sweage, septic tank, and stable, etc. The hydrogen and oxygen isotopic compositions indicate that five deep groundwaters were recharged from different altitudes, and that shallow and deep groundwaters were originated from meteoric water. Tritium contents of waters suggest that deep groundwater was recharged before or just after 1950s, and that shallow groundwater is much younger than deep groundwater. The results of this study may serve as a basic data for the future study of shallow groundwater as a drinking water in agricultural area, in Korea.