• Economic and Environmental Geology
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• v.37 no.6 s.169
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• pp.657-667
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• 2004

Arsenic was detected in the 29 water samples out of the 46 groundwaters located in the Ulsan metropolitan area and it's concentration ranges from $<0.1\;to\;72{\mu}g/L$. Among them the arsenic concentrations of three samples are over domestic drinking-water requirements $(50{\mu}g/L)$, and those of 10 samples are more than WHO MCLs, $10{\mu}g/L.$. High arsenic groundwater were recognized in the two region; one was near the tectonic line, especially Ulsan iron mine at Dalcheunri and the other was around Hyomundong distributed Jeongia conglomerate. It is estimated that the former is originated from pyrite oxydation type, oxygenated redox, whilst the latter is resulted from oxidation of reducted FeOOH. The species of arsenic in groundwater is in pentavalent arsenic, $H_2AsO_4^-,\;HAsO4_^{-2}$ near tectonic line, and trivalent arsenic, $H_3AsO_3$ around Hyomundong.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.10a
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• pp.123-125
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• 2005

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.10a
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• pp.87-88
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• 2005

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.10a
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• pp.91-92
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• 2005

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.09a
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• pp.78-82
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• 2003

Development of hematite-coated sand was evaluated for the application of the PRB (permeable reactive barrier) in the arsenic-contaminated subsurface of the metal mining areas. The removal efficiency of As(III) and As(V), the effect of anion competition and the capability of arsenic removal in the flow system were investigated through the experiments of adsorption isotherm, arsenic removal kinetics against anion competition and column removal. Hematite-coated sand followed a linear adsorption isotherm with high adsorption capacity at low level concentrations of arsenic (< 1.0 mg/l). When As(III) and As(V) underwent adsorption reactions in the presence of anions (sulfate, nitrate and bicarbonate), sulfate caused strong inhibition of arsenic removal, and bicarbonate and nitrate caused weak inhibition due to specific and nonspecific adsorption onto hematite, respectively. In the column experiments, high content of hematite-coated sand enhance the arsenic removal, but the amount of the arsenic removal decreased due to the higher affinity of As(V) than As(III) and reduced adsorption kinetics in the flow system, Therefore, the amount of hematite-coated sand, the adsorption affinity of arsenic species and removal kinetics determined the removal efficiency of arsenic in the flow system. arsenic, hematite-coated sand, permeable reactive barrier, anion competition, adsorption.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.04a
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• pp.13-16
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• 2005

Laboratory and field experiments were conducted to study the effectiveness of five adsorbents for the removal of arsenic. The adsorbents included activated alumina (AA), iron coated AA (ICAA), and granular ferric hydroxide (GFH), granular ferric oxide (GFO), and granular titanium dioxide (GTD). Laboratory experiments were conducted to investigate arsenic removal using challenge water prepared in accordance with NSF International Standards 53 (ANSl/NSF 53-2001). Field experiments were conducted using arsenic-contaminated groundwater In laboratory experiment, the treatment capacity decreased in the following order GTD > GFO > GFH. In contrast, the treatment capacity decreased in the following order GFO > GTD > GFH > ICAA > Ah in field experiments.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.04a
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• pp.318-322
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• 2004

Arsenic is a toxic and carcinogenic metalloid, whose sources in nature include mineral dissolution and volcanic eruption. Abandoned mines and hazardous waste disposal sites are another major source of arsenic contamination of soil and aquatic systems. To predict concentrations of the toxic inorganic arsenic in aqueous phase. the biogeochemical redox processes and transport behavior need to be studied together and be coupled in a reactive transport model. A new reaction module describing the fate and transport of inorganic arsenic species (As(II)), dissolved oxygen, nitrate, ferrous iron, sulfate, and dissolved organic carbon are developed and incorporated into the RT3D code.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.04a
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• pp.314-317
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• 2003

The overall objective of the adsorption study of arsenic was to elucidate the ability of iron coated sand(ICS), synthesized in the laboratory, to remove arsenic from polluted waters. Batch tests were conducted to provide a relation between arsenic removal and iron content of ICSs. The ICS, developed in the laboratory by coating iron onto the surface of ordinary sand by a simple and easy process has proved as an effective medium for use in removal of arsenic from waters over a wide range of particle sizes of ICS. The composite media is inexpensive to prepare and could serve as the basis of a useful arsenic removal process in variety settings.

• Bulletin of the Korean Chemical Society
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• v.35 no.2
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• pp.605-609
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• 2014

Magnetic multi-granule nanoclusters (MGNCs) were investigated as an inexpensive means to effectively remove arsenic from aqueous environment, particularly groundwater sources consumed by humans. Various size MGNCs were examined to determine both their capacity and efficiency for arsenic adsorption for different initial arsenic concentrations. The MGNCs showed highly efficient arsenic adsorption characteristics, thereby meeting the allowable safety limit of $10{\mu}g/L$ (ppb), prescribed by the World Health Organization (WHO), and confirming that 0.4 g and 0.6 g of MGNCs were sufficient to remove 0.5 mg/L and 1.0 mg/L of arsenate ($AsO_4{^{3-}}$) from water, respectively. Adsorption isotherm models for the MGNCs were used to estimate the adsorption parameters. They showed similar parameters for both the Langmuir and Sips models, confirming that the adsorption process in this work was active at a region of low arsenic concentration. The actual efficiency of arsenate removal was then tested against 1 L of artificial arsenic-contaminated groundwater with an arsenic concentration of 0.6 mg/L in the presence of competing ions. In this case, only 1.0 g of 100 nm MGNCs was sufficient to reduce the arsenic concentrations to below the WHO permissible safety limit for drinking water, without adjusting the pH or temperature, which is highly advantageous for practical field applications.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.10a
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• pp.176-177
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• 2005