• Korean Journal of Environmental Agriculture
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• v.41 no.4
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• pp.223-229
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• 2022

BACKGROUND: Mining activities, smelter discharges, and sludges are the major sources of heavy metal contamination to soils. The objective of this study was to determine the efficiency of magnetite and bottom ash derived from coal ash in remediating As-contaminated soil. METHODS AND RESULTS: An incubation experiment was conducted for 10 weeks. Magnetite and bottom ash at different rates and ratios were applied to each plastic bottle repacked with 1,000 g of dried As-contaminated soil. After 3-weeks of incubation, the concentrations of available As were measured by using Mehlich-3, SBET, and sequential extraction methods. All of the subjected soil amendments resulted in significant decreases in available As concentration compared to the controls. The addition of magnetite at the highest rate was the best to stabilize As in the soils; however, the values of As concentration varied with the extraction methods. CONCLUSION(S): To ensure the stabilization accuracy of heavy metals in soil, both single and sequential extractions are recommended. The magnetite derived from fly coal ash can also be applicable as a heavy metal stabilizer for the As-contaminated soil.

• 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.

• 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 Environmental Agriculture
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• v.15 no.1
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• pp.1-10
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• 1996

The contents of heavy metals in soil near the Janghang smelter area were observed to understand present status and relationship between their fraction and the absorption by rice. The soil samples were taken from the eight sites of the paddy fields in 1982 and 1990, and analysis on heavy metals including Cd, Zn, Cu and Pb was performed. The results were as follows: Total contents of heavy metals in the samples of 1990 were higher than those of 1982. The order of increasing ratio was Cu > Zn > Pb > Cd and the variation of Cd content by sequential differente extracting was residual > exchangeable > dilute acid-extractable fractions and its increasing range was from 38 to 71% during nine years. The ratio of immobile heavy metals bound within an oxide or silicate matrix of Fe-Mn oxide bound and residual in surface soil was that Cd, Pb, Cu and Zn were 31.65, 42.22, 76.57 and 79.49%, respectively, and their mobile ratios of exchangeable, dilute acid-extractable and organically bound were more than 20.28%. Those of mobile Cd, Pb, Cu and Zn were 68.35, 55.78, 23.43 and 20.28%, respectively. Correlation between the heavy metal contents in surface soil and those in tissue of rice plant, such as leaf blade, leaf sheath, stem and panicle axis, were significant, but were not significant in subsurface soil. The dilute acid-extractable and organically bound fractions of Cd, Cu, Pb and Zn in surface soil were more significantly correlated with those in tissues of paddy rice.

• Journal of the Korean Regional Science Association
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• v.37 no.4
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• pp.61-74
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• 2021

The objective of this study was to evaluate the community's capacity and hindrance factors affecting the community's activities by exploring the process of restoring the community's environmental pollution. This study examined the community activities related to the restoration of pollution that occurred at the former Janghang smelter in Seocheon-gun. The results of this study showed that leaders, cooperative resources, and the media were elements positively influencing the recovery of the community. The starting point that became the driving force for community activities was the presence of a leader who had a small stake in it. Moreover, it required cooperation such as the continuous interest of local active groups and residents to continue this effort. Above all, the media publicized the incident and amplified the activities of members. Meanwhile, there were various conflicts hindering the activities of local communities in the process of restoring the pollution such as the internal conflicts of community groups, conflicts between residents and active groups, and conflicts with the government. The behaviors that appeared in the process of restoring the pollution revealed a form of united governance. Moreover, they changed from an initial "supportive" character to "resistant" and "defensive" activities. Later, it was transformed into "subjective" and "creative" activities.

• Korean Journal of Environmental Agriculture
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• v.21 no.1
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• pp.31-37
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• 2002

In order to select proper plants for phytoremediation at heavy metal contaminated areas, eight species of non-edible plants were cultivated at the heavy metal contaminated soils near a metal smelter. The content of the absorbed heavy metals (Cd, Cu, Pb and As) at different part of the plants were analyzed. Plants included five tree species (Populus nigra x P. maximowiczii, Euonymus japonica, Acer palmantum, Celtis sinensis, Buxus microphylla), two flower species (Rhododendron lateritium, Calendula officinalis), and lawn (Zoysia japonica). Biomass yield of tree species was higher than those of flower or lawn species. Heavy metals were highly accumulated in roots compared to those In leaves and stems. The concentrations of Cd, Cu, Pb, and As in Buxus microphylla were greater than those in other plant species. Total absorbed Cd and Pb contents, from high to low by each plant in experimental plots were in the order of Populus nigra x P. maximowiczii, Celtis sinensis and Acer palmantum. They were Celtis sinensis, Populus nigra x P. maximowiczii and Buxus microphylla for Cu, and Buxus microphylla, Acer palmantum and Populus nigra x P. maimowiczii for As. It was estimated that among eight plant species used in the experiment Populus nigra x P. maximowiczii, Buxus microphylla, Acer palmantum, and Celtis sinensis were the most effective species for phytoremediation in the heavy metals polluted areas considering biomass yield and heavy metal uptake.