• Korean Journal of Soil Science and Fertilizer
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• v.48 no.4
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• pp.278-284
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• 2015

In general, plant roots accumulate more heavy metals than the above ground organs such as leaf, stem, and fruit. This implies that root medicinal plants would be an issue with excessive heavy metal accumulation. Therefore, the current study was carried out to investigate the distribution of heavy metal (focused on Cd and Pb) concentrations in soils and medicinal plant roots grown in different region of Korea. Total 293 samples for each soil and plant were collected along the national wide. Soil pH, total and phytoavailable metal concentrations (1 M $NH_4NO_3$ extracted) in soils were determined and heavy metal concentrations in root of the medicinal plants were analyzed. Heavy metal concentrations of the soil samples studied were not exceeded standard limits legislated in 'Soil Environmental Conservation Act', except 2 samples for Cu. However, substantial amount of Cd was accumulated in medicinal plant roots with 29% samples exceeding the standard limit legislated in 'Pharmaceutical Affairs Act' while all plant samples were lower than the standard limit value for Pb. Also the current study demonstrated that cadmium concentrations in the roots were governed by the phytoavailable Cd in soils, which decreased as soil pH increased. From this result, application of heavy metal immobilization technique using a pH change-induced immobilizing agents can be suggested for safer root medicinal plant production.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.9
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• pp.670-676
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• 2011

Artificially metal-contaminated soils have been widely used for lab-scale soil washing and soil toxicity experiments. The artificial soil contamination methods consist of 1) first equilibrating soils with heavy metal solution, 2) filtrating or centrifuging soils from the mixture and 3) finally drying the soils. However, some of those artificially contaminated soil experiments have not clearly shown that the soils were thoroughly rinsed with water prior to conducting experiments. This study investigated the amount of heavy metal release from the artificially metal-contaminated soil by pre-water-rinsing. Three different artificially metal-contaminated soil preparation methods were first evaluated with Cd and Pb concentrations of soil. Then, this study investigated the effect of pre-water-rinsing on the Cd and Pb concentration of the artificially contaminated soil. Heavy metal concentrations of the soil produced by equilibrating and drying the metal solution-soil were significantly reduced by pre-water-rinsing. The results of the study implied that experimental results would be significantly distorted when the artificially heavy metal-contaminated soils were not thoroughly water-rinsed prior to conducting experiments. Therefore, the initial heavy metal concentration of the artificially contaminated soil should be determined after thoroughly rinsing the soil that was previously obtained through the adsorption and dry stages.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.6
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• pp.540-546
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• 2014

Acid mine drainage sludge (AMDS) has been classified as mine waste and generally deposited in land. For this reason, studies have been conducted to examine the possibility of recycling AMDS as an amendment for heavy metal stabilization in soil. The main objective of this study was to evaluate heavy metal stabilization efficiency of AMDS comparing with the widely used lime stone. Also, optimum mixing ratio was evaluated for enhancing heavy metal stabilization. AMDS and limestone were mixed at the ratio of 0:100, 25:75, 50:50, 75:25, and 100:0 with five different heavy metal solutions ($100mg\;L^{-1}$ of $NaAsO_2$, $CdCl_2$, $CuCl_2$, $Pb(NO_3)_2$, and $ZnSO_4{\cdot}7H_2O$). The amendments were added at a rate of 3% (w/v). In order to determine the stabilization kinetics, samples were collected at different reaction time of 0, 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024 minutes. The heavy metal stabilization by AMDS was faster and higher than those of limestone for all examined heavy metals. While limestone showed only 20% of arsenic (As) stabilization after 1,024 minutes, 96% of As was stabilized within 1 minute by AMDS. The highest effect on the stabilization of heavy metal (loid) was observed, when the two amendments were mixed at a ratio of 1:1. These results indicated that AMDS can be effectively used for heavy metal stabilization in soil, especially for As, and the optimum mixing ratio of AMDS and lime was 1:1 at a rate of 3% (w/v).

• Journal of Soil and Groundwater Environment
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• v.16 no.4
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• pp.23-30
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• 2011

Risk based pollution level of Pb and Cd in metal contaminated soils depending on physicochemical properties of soil in a target site was assessed using biotic ligand model. Heavy metal activity in soil solution defined as exposure activity (EA) was assumed to be toxic to Vibrio fischeri and soil organisms. Predicted effective activity (PEA) determined by biotic ligand model was compared to EA value to calculate risk quotient. Field contaminated soils (n = 10) were collected from a formes area and their risk based pollution levels were assessed in the present study using the calculated risk quotient. Concentrations of Pb determined by aqua regia were 295, 258, and 268 mg/kg in B, H and J points and concentrations of Cd were 4.73 and 6.36 mg/kg in G and I points, respectively. These points exceeded the current soil conservation standards. However, risk based pollution levels of the ten points were not able to be calculated because concentrations of Pb and Cd in soil solution were smaller than detection limits or one (i.e., non toxic). It was because heavy metal activity in soil solution was dominant toxicological form to organisms, not a total heavy metal concentration in soil. In addition, heavy metal toxicity was decreased by competition effect of major cations and formation of complex with dissolved organic carbon in soil solution. Therefore, it is essential to consider site-specific factors affecting bioavailability and toxicity for estimating reliable risk of Pb and Cd.

• The Korean Journal of Ecology
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• v.27 no.4
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• pp.231-237
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• 2004

In this research we determined the levels of heavy metals in soil and metal-accumulating plants from a D military shooting site in the Kyungkido district of Korea. The data obtained may be useful in the development of methods for the efficient phytoremediation of contaminated soil. The total Cd, Cu, Pb, and Zn concentrations in the soil were found to be 1.67-5.04 mg/kg, 52.51-106.26 mg/kg, 37.24-90.32mg/kg, and 111.45-188.19mg/kg, respectively. These results show that the soil is contaminated with Cd and Cu, and this contamination is particularly severe in the case of Cd because of its high bioavailability (25-57% of the total metal in the soil is exchangeable). The high concentrations of heavy metals in the shoots of Persicaria thunbergii and Artemisia princeps var. orientalis indicate that these plants (all perennial herbs) accumulate heavy metal efficiently. Further, these plants were found to contain more Cd in its shoots (＞60% of the total metal found in the plant) than any other plant; these results indicate that these native species are particularly suited to use in Cd phytoextraction.

• Journal of Environmental Health Sciences
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• v.27 no.3
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• pp.57-62
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• 2001

The study was conducted to measure the heavy metal pollution of soils at the playground for children and to investigate the characteristics of heavy metals distribution I city. The studied area was divided into two: the residential area and the industrial area. The samples of the sands and soils were collected from both areas. The results were obtained as follows. All average concentration of 6 different heavy metals was found to be lower than the standard of soil pollution. Zn, Pb and cu concentrations were higher than other species of heavy metals. The contents of heavy metals in the soil were higher than the sands. The average contents of Zn, Pb, Cu, As, Hg and Cd in soil were 38.36, 9.53, 7.31, 0.03, 0.18 and 0.09 mg/kg respectively. Comparing with the residential area, heavy metal concentrations of the industrial area were 4.60, 1.49, 2.60 and 4.29 times for Zn, Pb, Hg and Cd in soils, respectively.

• The Korean Journal of Ecology
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• v.26 no.2
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• pp.65-70
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• 2003

Shihwa tidal freshwater marsh was constructed recently to treat pollutants entering Shihwa lake. In this study, we examined the spatial and temporal patterns of heavy metal accumulation in soils of Shihwa marsh and sought correlations between several soil variables (pH, electrical conductivity, organic matter, and acid ammonium oxalate-extractable Fe and Al contents) and the heavy metal concentration of soils. Surface soil samples (0∼20 cm) were collected in June 2000, November 2000, and July 2001, and were analyzed for heavy metals (Zn, Cd, Pb, Cu, Cr, As, and Hg) and soil chemical properties. The neutral pH and water-saturated conditions of Shihwa marsh appeared to favor immobilization of heavy metal through adsorption onto soils. The concentrations of heavy metal (especially Zn, Cu, and Cr) in soils of Shihwa marsh increased along the sampling occasions, suggesting that soils of Shihwa marsh serve as a sink of heavy metal. Among the sub-marshes, metal concentrations were highest in Banweol high marshes and lowest in Samhwa marshes. The temporal and spatial variations in the heavy metal concentrations of soils were correlated positively with organic matter and oxalate extractable Fe and Al contents, but negatively with electrical conductivity. These results suggest that organic matter and hydrous oxide of Fe/Al may playa key role in removing heavy metals in soils of Shihwa marsh, and that heavy metal removing capacity would increase with desalinization. However, the removal patterns of heavy metal by reeds warrant further studies to evaluate the total removal capacity of heavy metals by Shihwa marsh.

• 한국환경농학회:학술대회논문집
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• 2009.07a
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• pp.93-115
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• 2009

There are growing public concerns over crop and food safeties due to the elevated levels of heavy metals grown in contaminated soil. Heavy metals are classified as the chemical harmful risks for crop and food safety. With implementation of GAP, crop safety is controlled by many regulatory options for soil, irrigation water and fertilizers. Any attempt to retard the metal uptake by crops may be the best protocol to secure crop and food safety. This article reviews the management strategies for heavy metals in view of crop safety in Korea and demonstrates results from the field experiments to retard metal translocation from soil to crops by using chemical amendments and soil layer management methods. Major source of soil pollution by heavy metals has been related with mining activities. Risk assessment revealed that rice consumption and groundwater ingestion in the abandoned mining areas were the major exposure pathways for metals to human and the heavy metal showed the toxic effects on human health. Chemical amendments such as lime and slag retarded Cd uptake by rice (Oryza sativa L.) by increasing soil pH, lowering the phytoavailable Cd concentration in soil solution, immobilizing Cd in soil and converting the available Cd fractions into non-available fractions. The soil layer management methods decreased the Cd uptake by 76% and Pb by 60%. Either reversing the surface layer with subsurface layer or immobilization of metals with layer mixing with lime was considered to be the practical option for the in-situ remediation of the contaminated paddy soils. Combination of chemical soil amendments and layer management methods was efficient to retard the metal bioavailability and thus to secure crop safety for heavy metals. This protocol seems to be cheap, relatively easy to practice and practical in the agricultural fields. However, a long term monitoring work should be followed to verify the efficiency of this protocol.

• Economic and Environmental Geology
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• v.53 no.5
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• pp.517-528
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• 2020

The objectives of this study were to select optimal soil amendments through analysis of heavy metal availability in soil and uptake to Miscanthus sinensis Anderss. for phytostablization in heavy metal contaminated soil of abandoned metal mine. M. sinensis was cultivated for 6 months at contaminated soil with several soil treatments (bottom ash 1 and 2%, fly ash 1 and 2%, waste lime+oyster 1 and 2%, acid mine drainage sludge (AMDS) 10 and 20%, compost 3.4%, and control). The analysis results of heavy metal concentrations in the soil by Mehlich-3 mehthod, growth and heavy metal concentrations of M. sinensis showed that AMDS 20% was more effective than other amendments for phytostablization, and AMDS 10% showed second effectiveness. Waste lime+oyster, bottom ash and fly ash were also improved compared to control. Mobility of some heavy metal was increased by treatments. Therefore, it is necessary of preparatory investigation of soil condition to select soil amendment to apply on-site phytostablization.

• Journal of Environmental Science International
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• v.19 no.5
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• pp.585-590
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• 2010

This study attempted to facilitate various groundcover plants, related to phytoremediation material, and advance shade plants with a heavy metal tolerance to contaminated soil in an urban shade space. Saxifraga stolonifera, which has commonly been used a landscape shade plants, was evaluated to determine its heavy metal tolerance to different concentrations(Control, $100mg{\cdot}kg^{-1}$, $250mg{\cdot}kg^{-1}$ and $500mg{\cdot}kg^{-1}$ treatment) of Cd, Pb and Zn in soil. The growth of Saxifraga stolonifera showed no significant tendency after the initial transplantation, but showed distinct changes with the respective treatment heavy metal types and concentrations over time. Especially, severe chlorosis, with more yellowish green leaves, was observed, with inhibition at Cd concentrations greater than $100mg{\cdot}kg^{-1}$. Conversely, no external symptoms or growth retardation were observed with Pb and Zn concentrations less than $500mg{\cdot}kg^{-1}$. Therefore, Saxifraga stolonifera can be applied as a long term phytoremediation species in soil contaminated with low concentrations of heavy metal in urban shade spaces.