• Environmental Engineering Research
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• v.19 no.2
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• pp.145-149
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• 2014

Arsenic (As) is one of the heavy metals which causes acute bio-toxicity even at low concentration and has disastrous effect on environment. In some countries, As contamination has become alarming and increasing day by day as consequences of unsustainable management practices. Many existing physical, chemical and biological processes for As removal from water system are not feasible due to techno-economic limitations. The present study highlights the scope of biological strategy for As removal through phytoextraction. Arsenic uptake and accumulation in the biomass of three plant species and their As tolerance abilities have been investigated to develop an efficient phytoextraction system in combination of these plant species. Three non-crop plant species, Pteris vittata; Mimosa pudica, and Eichhornia crassipus were treated with 0-200 mg/L As in liquid nutrient solution for 14 days. P. vittata accumulated total 9,082.2 mg (8,223 mg in fronds) As/kg biomass and Eichhornia total 6,969 mg (4,517 mg in fronds)/kg biomass at 200 mg/L As concentration, respectively. Bioaccumulation factor (BF) and translocation factor (TF) were estimated to differentiate between excluders, accumulators and accumulation in above ground biomass. Pteris and Eichhornia have highest BF (67 and 17) and TF (64 and 3), respectively. In contrast, Mimosa accumulated up to 174 mg As/kg plant biomass which is low in comparison with other two plants, and both BF and TF were ${\leq}1$. This study reveals that Pteris and Eichhornia are As hyperaccumulator, and potential candidates for As removal from water system.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.6
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• pp.634-640
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• 2015

Chelating agents have been proposed to improve the efficiency of phytoextraction of heavy metal hyperaccumulator. However, little studies to elucidate mechanism of chelating agents to increase cadmium (Cd) extractability have been conducted. The objectives of this study were to evaluate effect of different chelating agents on Cd extractability and to determine mechanism of Cd mobilization affected by these agents. An arable soil was spiked with inorganic Cd ($CdCl_2$) to give a total Cd concentration of $20mgCdkg^{-1}$. Ethylenediaminetetraacetic acid (EDTA) and citric acid (CA) were selected and mixed with the arable soil at the rates of 0 and $5mmolkg^{-1}$. The mixture soils were incubated at $25^{\circ}C$ for 4 weeks in dark condition. Concentration of F1 Cd fractions (water soluble) significantly increased with addition of EDTA but did not changed with addition of CA. Especially; concentration of F5 Cd fractions (residual) significantly increased with addition of CA. Increase in water soluble with EDTA might be attributed to complexation of Cd and EDTA. Dissolved organic carbon concentration significantly increased with EDTA addition, but did not with CA implying that considerable amount of CA was decomposed to inorganic carbon by microorganism. Log activity of carbonate ($CO_3{^{2-}}$) which might be generated from CA increased with addition of CA. Increase in residual Cd fraction might be due to precipitation of Cd as $CdCO_3$. As a result, EDTA was effective in increasing Cd extractability, by contrast CA had significant effect in reducing Cd extractability.

• Korean Journal of Plant Resources
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• v.30 no.2
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• pp.160-166
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• 2017

This study was performed to develop the efficient phytoremediation model in the paddy soil contaminated with heavy metals by cultivating Pteris multifida and Artemisia princeps with different mixing ratios (1:0, 8:1, 6:1, 4:1). As a result of investigating the heavy metal accumulation of each plant per dried material (1 kg), content of arsenic and cadmium was the highest in aerial part of P. multifida (169.82, $1.70mg{\cdot}kg^{-1}DW$, each) among the treated group. Lead content was the highest ($12.58mg{\cdot}kg^{-1}DW$) in the aerial part of P. multifida cultivated with 8:1 mixed planting. But the content of copper and zinc was the highest (33.94, $61.78mg{\cdot}kg^{-1}DW$, each) in the aerial part of A. princeps with 8:1 treatment. Regardless of heavy metals, plant uptake from the $1m^2$ soil was the highest in 4:1 mixed planting group, which showed the best yield of A. princeps.

• Korean Journal of Environmental Agriculture
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• v.18 no.1
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• pp.28-34
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• 1999

This study was carried out to assess heavy metal pollution at 16 abandoned mining areas and to get basic data for phytoremediation. In most of surveyed area, there was no vegetation cover and soil reaction shows in low to moderate pH. Low CEC, low organic matter content were the general properties of these soils. Heavy metals content of these soils were exceed background level of unpolluted soil in Korea, especially Cu content was 2,634mg/kg at Jeil site, 3,415mg/kg Zn, 8.03mg/kg Cd at Yonhwa 2 site. This is far above tolerance limit In plant survey, very often observed plants were Pinus densiflora, and Rohinia psuedo-acacia in woody plant, Artemisia princeps, and Dianthus sinensis in herbs. Artemisia princeps had higher concentration of Zn, Cd and Dianthus sinensis had higher concentration than other plants. From the results, heavy metal concentration in plants and plant's ecotype properties, could be said that Artemisia princeps and Miscanthus sinensis have a potential of soil remediation plant. More studies are demanded to find the heavy metal tolerance species and to understand physiology property of tolerance plants, soil condition, climate etc., for successful soil remediation by plants.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.4
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• pp.280-291
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• 2007

Much research has been conducted in the field of phytoremediation since the discovery of the range of plants known as hyperaccumulators. Research has focused simultaneously on elucidating the mechanism of metal(loid) accumulation and development of practical techniques to enhance accumulation efficiency. To date, it is generally understood that there are five specific mechanisms employed by hyperaccumulating plant species that are either not or under utilized by non-hyperaccumulators. These include 1) enhanced metal(loid)s uptake through the root cell, 2) enhanced translocation in plant tissue, 3) detoxification and sequestration, 4) enhanced metal availability in soil:root interface, and 5) active root foraging toward metal(loid) enriched soils. Among these mechanisms, understanding of the plant-root effect on metal(loid) dynamics and subsequent plant uptake is vital to overcome the inherit limitation of phytoremediation caused by low metal(loid) solubility in soils. Plant roots can influence the soil chemistry in the rhizosphere through changes in pH and exudation of organic compounds such as low-molecular-weight organic acids (LMWOAs) which consequently change metal(loid) solubility. The decrease in soil pH by plant release of $H^+$ results in increased metal solubility. Elevated levels of organic compounds in response to high metal soil concentrations by plant exudation may also increases metal concentration in soil solution through formation of organometallic complexes.

• Applied Biological Chemistry
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• v.40 no.3
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• pp.243-248
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• 1997

In order to evaluate the usefulness of O. javanica for the phytoremediation, it was grown for 1, 3, 7, 14, 21 days and was exposed to $50\;{\mu}M\;of\;CdCl_2$ in hydroponic medium after 3 weeks. Its biomass and contents of chlorophylls were analyzed. The growth of O. javanica showed little difference between cadmium treated and non-treated groups, while its contents of chlorophylls of Cd-treated group decreased up to 50% compared to the case of non-treated group. Its accumulated cadmium concentrations were 2.1, 7.3 and $113\;{\mu}moles\;Cd/g$ dry weight in the leaf, stem and root, respectively. The total contents of thiol increased 0.5, 1 and 7 times in the leaf, stem and root, respectively, while the contents of glutathione tended to decrease by 43%, 70% and 47% in the leaf, stem and root, respectively. Using HPLC analysis, the reasonable peaks of thiol compounds in shoot and root of Cd-treated sample were compared to those of non-treated sample in O. javanica, and found to be phytochelatins. In case of Nicotiana tabacum cv. Xanthi tested as control plant, the cadmium treatment for 3 weeks resulted in the decrease of both biomass and chlorophyll up to 70% and 75%, respectively. The roots of tobacco became rotten and eventually died. These results suggested that Oenanthe javanica is cadmium-tolerant hyperaccumulator.(Received December 20, 1996; accepted March 17, 1997)

• Ecology and Resilient Infrastructure
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• v.8 no.4
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• pp.290-298
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• 2021

This study was conducted to evaluate the possibility of applying phytoremediation technology by investigating soil and native plants in waste coal landfills exposed to heavy metal contamination for a long period of time. The ability of native plants to accumulate heavy metals using greenhouse cultivation experiments was alse evaluated. Plants were investigated at an abandoned coal mine in Hwajeolyeong, Jeongseon, Gangwon-do. Two species of native plants (Carex breviculmis. R. B. and Salix koriyanagi Kimura ex Goerz.) located in the study area and three Korean native plants (Artemisia japonica Thunb. Hemerocallis hakuunensis Nakai., and Saussurea pulchella (Fisch.) Fisch.) were cultivated in a greenhouse for 12 weeks in artificially contaminated soil. Soils contaminated with arsenic and lead were generated with arsenic concentration gradients of 25, 62.5, 125, and 250 mg kg^-1 and lead concentration gradients of 200, 500, 1000, and 2000 mg kg^-1, respectively. Results showed that none of the five plants could survive at high arsenic concentration treatment (125 and 250 mg kg^-1) and some plants died in 2000 mg kg^-1 lead concentration treatment soil. The plant translocation factor (TF) was highest in H. hakuunensis in arsenic treatments, and A. japonica in lead treatments, respectively. The bioaccumulation factor (BF) of plants was more than 1 in all species in arsenic treatment, whereas it was highest in H. hakuunensis. BF for all species was less than 1 in lead treatment. Particularly, in 2000 mg kg^-1 concentration lead treatment, A. japonica accumulated more than 1000 mg kg^-1 lead and was expected to be a lead hyperaccumulator. In conclusion, A. japonica and H. hakuunensis were excellent in the accumulation of arsenic heavy metals, and S. koriyanagi was excellent in lead accumulation ability. Therefore, the above mentioned three plants are considered to be strong contenders for application of the phytoremediation technology.