• Journal of Soil and Groundwater Environment
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• v.22 no.6
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• pp.1-11
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• 2017

This study was conducted to investigate the performance of four commercial chemical agents in stabilizing arsenic (As) in soil at the forest area near the former Janghang smelter site. After amending the stabilizing agents (A, B, C, and D) into As-contaminated soil samples, synthetic precipitation leaching procedure (SPLP) and solubility bioavailability research consortium (SBRC)-extractable As concentrations significantly decreased except for agent D, which is mainly composed of fly ash and calcium carbonate. Increase of SPLP and SBRC-extractable As concentrations in four soil samples (S1, S2, S3, and J2) was attributed to desorption of As adsorbed on iron oxides due to high pH generated by agent D. It is therefore necessary to consider application conditions according to soil characteristics such as pH and buffering capacity. Results of sequential extraction showed that readily extractable fractions of As in soil (i.e., sum of $SO_4-$ and $PO_4-extractable$ As in soil) were converted into non-readily extractable fractions by amending agents A, B, and C. Such changes in the As distribution in soil resulted in the decrease of SPLP and SBRC-extractable As concentration. A series of follow-up monitoring and management plan has been suggested to assess the longevity of the stabilization treatments in the site.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.17 no.1
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• pp.1-12
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• 2014

This study was carried out not only to identify the optimum concentrations of sulfur powder and citric acid treated for improving arsenic absorption of Pteris multifuda known as hyperaccumulator of arsenic, but also to develop arsenic purification model in the forest soil. After applying sulfur powder (0, 30, 45, $60g{\cdot}m^{-2}$) and citric acid (0, 200, 400, $800g{\cdot}m^{-2}$) in the forest soil contaminated with heavy metals, P. multifuda was planted and cultivated for 16 weeks. And then the growth and arsenic contents of plants were analyzed. In the result of research, the growth of P. mulifuda, except plant width, cultivated in soils treated with sulfur powder and citric acid was relatively lower than control. The accumulated amount of arsenic in aerial parts of P. multifuda ($1822.2mg{\cdot}kg^{-1}$) cultivated in soils treated with $200g{\cdot}m^{-2}$ citric acid was improved 62.5% against the control. And the accumulated amount of arsenic per 1 $m^2$ ($20.1mg{\cdot}m^{-2}$) was the greatest in $200g{\cdot}m^{-2}$ citric acid treatment. Translocation rate (TR) was higher in all acid treatment compare to control, and was the best in $200g{\cdot}m^{-2}$ citric acid treatment (0.95) especially. It showed that the arsenic absorbed in underground parts was transferred fast to aerial parts. Therefore, $200g{\cdot}m^{-2}$ citric acid treatment in the soil is recommended for arsenic purification using P. multifuda.

• Korean Journal of Plant Resources
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• v.24 no.1
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• pp.48-54
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• 2011

This study was performed to analyze the possibility of using Korean native Aster koraiensis Nakai for phytoremediation at various fields. A. koraiensis was cultivated at paddy, upland and forest soils contaminated with heavy metals. After 8 weeks of cultivation, and growth and its absorbing capacity of heavy metals were analyzed. The results showed that A. koraiensis was grown well even at the soil highly contaminated with heavy metals, which means it has a tolerance to heavy metals. As analysis results of arsenic, cadmium, copper, lead and zinc contents absorbed from various soils contaminated with heavy metals, heavy metal absorbing capacity of A. koraiensis was depending on the heavy metal contents in the soils and soil property. In case of arsenic, cadmium and copper, heavy metal accumulation capacities of Aster koraiensis were much influenced by contents of heavy metals in the soils. Absorbing capacity of plants was increased when heavy metal contents in the soils were high. Lead absorbing capacity was depending more on soil property than lead contents in the soil, and was great at sandy soil of forest. Zinc absorbing capacity was influenced by both soil properties and Zn contents in the soil, was increased at paddy soil contaminated with high concentrations of heavy metals and upland soils. In general, A. koraiensis had a tolerance to heavy metals and showed great absorbing capability of heavy metals. So A. koraiensis can be used as a good landscape material for phytoremediation at various soils contaminated with heavy metals.

• Journal of the Korean GEO-environmental Society
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• v.13 no.3
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• pp.59-70
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• 2012

In this study, to select the best stabilizer for the heavy metals-contaminated soil from a smelter area during phytoremediation, a plant uptake experiment and a soil stabilization were simultaneously applied using Pteris multifida Poir. and five pre-screened stabilizers(zeolite, Mn dioxide, slag, Ca oxide, and magnetite). The extracted heavy metal was measured and compared using a 3 step sequential extraction for the soil samples. The growth rate of the plant was also evaluated. The stabilizers stabilized heavy metals in soil and reduced the extraction rate. Magnetite and calcium oxide showed better results than other stabilizers. The stabilizers enhanced the growth of the plant. All the heavy metals except for arsenic were concentrated in roots while arsenic was concentrated in leaves of the plant. It is concluded that the stabilizers can minimize the heavy metal release from the contaminated soil during phytoremediation and stimulated the growth of plant. These effects of stabilizers could compensate for some weak points of phytoremediation such as reaching of heavy metals by rainwater.

• 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.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.12
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• pp.1095-1104
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• 2009

The objective of this research was to evaluate the feasibility of using oyster-shell and eggshell wastes for the stabilization of arsenic-contaminated soil. Artificial As(V) contaminated soil was mixed with 0~5% oyster-shell and eggshell wastes and each sample was incubated for 30 days in a controlled environment. The efficiency of each treatment was evaluated using various single extractants (1 N HCl, 0.1 N NaOH and 0.5 N $H_2SO_4$). The concentration of As(V) was reduced by 10% upon a 5% oyster-shell or eggshell waste treatments based on the Korea Standard Test method (1 N HCl extraction). Analogous trends were observed in the 0.1 N NaOH or 0.5 N $H_2SO_4$ extractions. In addition, the oyster-shell and eggshell waste treatments increased the pH of each soil from 6.54 (Control) to 7.62~7.94. The exchangeable Ca in each soil also sharply increased from 6.87 cmol(+)/kg (Control) to 12.77~20.18 cmol(+)/kg. Further research is needed to increase the effectiveness of the oyster-shell and eggshell waste for the stabilization of As(V) in the contaminated soil.

• Korean Journal of Environmental Agriculture
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• v.38 no.1
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• pp.17-22
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• 2019

BACKGROUND: Soil contamination of As is a very sensitive environmental issue due to its adverse impact on human health and different characteristics with other heavy metals. With public awareness of As poisoning, there has been growing interest in developing guideline and remediation technologies for As-contaminated soil. The objective of this research was to evaluate the effectiveness of stabilizing amendments and soil dressing methods on the mobility of As in the contaminated rice paddy soils nearby mining area. METHODS AND RESULTS: Different amendments were mixed with surface and subsurface contaminated soils at a ratio of 3% (w/w) and monitored for five months. Three different extractants including 0.01M $CaCl_2$, TCLP, and PBET were used to examine As bioavailability in the soil and the concentration of As in rice grain was also measured with an inductively coupled plasma (ICP) spectroscopy. The results showed that all amendment treatments decreased As concentration compared to the control. Especially, coal mine drainage sludge (CMDS) treatment showed the highest efficiency of decreasing As concentration in the soil and rice grain. The values of Pearson correlation (r) between As concentrations in the soil and rice grain were 0.782, 0.753, and 0.678 for $CaCl_2$, TCLP, and PBET methods, respectively. Especially, $CaCl_2$ method was highly correlated between As concentrations of the soil and soil solution (r=0.719), followed by TCLP (r=0.706), PBET (r=0.561) methods. CONCLUSION: Stabilizing amendments can effectively reduce available As concentration in the soils as well as soil solution, and thereby potentially mitigating risks of crop contamination by As.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.1
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• pp.58-66
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• 2011

Arsenic pollution is a serious global concern which affects all life forms. Being a toxic metalloid, the continued search for appropriate technologies for its remediation is needed. Phytoremediation, the use of green plants, is not only a low cost but also an environmentally friendly approach for metal uptake and stabilization. However, its application is limited by slow plant growth which is further aggravated by the phytotoxic effect of the pollutant. Attempts to address these constraints were done by exploiting plant-microbe interactions which offers more advantages for phytoremediation. Several bacterial mechanisms that can increase the efficiency of phytoremediation of As are nitrogen fixation, phosphate solubilization, siderophore production, ACC deaminase activity and growth regulator production. Many have been reported for other metals, but few for arsenic. This mini-review attempts to present what has been done so far in exploring plants and their rhizosphere microbiota and some genetic manipulations to increase the efficiency of arsenic soil phytoremediation.

• Proceedings of the Microbiological Society of Korea Conference
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• 2009.05a
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• pp.65-66
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• 2009

• Journal of Environmental Impact Assessment
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• v.32 no.3
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• pp.157-165
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• 2023

In Korea, a major contaminant of farmland soils in the vicinity of abandoned mines is arsenic, for which the general soil reclamation method is contaminated soil stabilization and cover the stabilized soil with clean soil at a thickness of 40 cm. In a previous pot experiment study we confirmed the feasibility of a lower thickness (20 cm) of covering soil for such reclamation in abandoned coal mines, where arsenic contamination levels are generally lower than in metal mines. In this subsequent study a field experiment including rice plant cultivation in field test plots was conducted. For over 4 months, the transfer of arsenic from the contaminated soil to the unpolished rice grains was reduced by 44% when a clean soil covering with a thickness of 20 cm was applied. The maximum decrease (56%) was shown when the stabilization process was performed before the covering. These results reveal a lower thickness of clean soil covering has a high feasibility and it can increase cost-efficiency in the reclamation of an abandoned coal mine.