• Korean Journal of Environmental Agriculture
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• v.24 no.2
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• pp.106-116
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• 2005

This experiment was conducted to investigate available extraction capacity and potential mobility of heavy metal according to the distribution property and contamination level of heavy metals in soils and to suggest a reform measure of soil environment assessment methodology applied with soil quality and the official soil heavy metal test methods in domestic and foreign countries. The soils were collected from the natural forest paddy with long-term application of same type fertilizer, and paddies near metal mine and industrial complex. The post-treatment methods of soil were partial extraction, acid digestion and sequential extraction methods. For the heavy metal contents with different soil properties, it was shown that their natural forest and paddy soil were slightly low and similar to the general paddy soil, while their paddies near metal mine and industrial complex were higher than the standard level of Soil Environment Protection Act. Heavy metal concentrations in the soils with different soil properties had difference between $HNO_3\;and\;HNO_3+HCl$ extractant by US-EPA 3051a method. There were highly significant positive relationships in both two methods. It was appeared that the higher extractable concentration ratio with 0.1N-HCl to total heavy metal content with $HNO_3+HCl$ extractant the greater total heavy metal content. There were highly significant positive correlationship between total heavy metal content and extractable content with 0.1N-HCl. For extractable capacity of soil extractable solution compared to the total heavy metal content it was appeared that it extractable method with 0.1N-HCl was higher than those with EDTA and DTPA. In extractable ratio with 0.1N-HCl in the contaminated paddy soils near mine and industrial complex, it was shown that the lower soil pH, the higher total heavy metal content. The order of a potential mobility coefficient by distribution of heavy metal content with ie different typies in the soil was Cd>Ni>Zn>Cu>Pb. It could be known that contamination characteristics of heavy metals with different types of soils were affected by different heavy metal components, contamination degree and soil chemical properties, and heavy metal concentration with different extractable methods had great variations with adjacent environment. To be compared with assessment methodology of soil environment impact at domestic and foreign countries with our results, it might be considered that there was necessary to make a single analysis method based on total heavy metal content with environmental overloading concept because of various analysis methods for total heavy metal content and present analysis method with great variation according to soil environment. In spite of showing higher concentration of heavy metal with acidic digestion than the extractable method, it might be considered that there is need to be adjusted the national standard of soil heavy metal contamination.

• Journal of the Korean Society of Food Culture
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• v.27 no.1
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• pp.75-81
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• 2012

This study was conducted to investigate the physiological activity of acai berry (Euterpe oleracea Mart.) extracts from three different solvents (water, methanol, and ethanol). We measured total polyphenol and total flavonoid content, DPPH radical scavenging activity, nitrite scavenging activity, metal chelating effect, and reducing power. The extraction yield from water, methanol, and ethanol was 17.10, 9.50, and 37.51%, respectively. The highest total polyphenol content (10.54 mg/100 g) and total flavonoid contents (1.88 mg/100 g) was observed in water extract. DPPH radical scavenging activity was the highest in both water extract (72.03%) and methanol extract (74.79%) at levels of 5 mg/mL, which was similar to that of BHT (78.90%). Water extract yielded the highest metal chelating effect (92.54%) and reducing power (1.09) at levels of 5 mg/mL. Taken together, these findings suggest that extracts of acai berry can be used as functional food materials with antioxidative and nitrite scavenging activities.

• Advances in Traditional Medicine
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• v.7 no.2
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• pp.162-170
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• 2007

Woodfordia fruticosa Kurz. (Lythraceae), commonly known as Dhayero, is used in the treatment of various ailments in Nepal. In this study, the antioxidant capacity of crude extract and different polarity fractions of Woodfordia fruticosa flowers were assayed for their scavenging abilities against 1,1-diphenyl-2-picrylhydrazyl (DPPH) and nitric oxide radicals, competitive ${\beta}$-carotene bleaching, reducing power, metal chelating ability and total phenolic content. Crude extract and polar fractions showed stronger antioxidant capacity and contained very high level of total phenolics. They exhibited strong DPPH radical scavenging, nitric oxide scavenging and reducing power, medium ${\beta}$-carotene bleaching and poor metal chelating capacity. Positive correlation obtained between total phenolic content and antioxidant capacity assays, indicated the contribution of phenolics toards antioxidant capacity.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1999.10c
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• pp.651-656
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• 1999

This study was carried out to investigate the paddy soil and water quality in Boryung freshwater reservoir watershed during the non-cropping season. Soil pH of the Boryung freshwater reservoir watershed were 5.39∼5.78. Total-N and P contents were high by the accumulation of chemical fertilizer partly. Heavy metal content of paddy soils were natural background level. Water pH of the Boryung freshwater reservoir watershed ranged from 6.82 to 8.64. Total-N content affected by a livestock wastes and sewage water were the higher than that of others and total-P content showed below 0.1mg/L. Nitrate nitrogen contents was very high according to the influence a livestock waste and sewage water partly. Heavy metal contents of wateers were natural background level.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.10 no.1
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• pp.32-44
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• 2000

The practice of welding stainless steel is known to produce various valance states of chromium. $CO_2$ flux cored arc welding on stainless was performed in fume collection chamber. Content of total chromium and hexavalent chromium in fumes, content of hexavalent chromium in total chromium, solubility of hexavalent chromium were investigated. Content of total chromium in fumes increases from 2~3% to 7~9% as a function of input energy, but hexavalent chromium, less than 1.2% in fumes, is not related to input energy. Hexavalent chromium in fumes exists as solubles up to 90%. Content of total chromium in flux cored arc welding fumes and solubility of hexavalent chromium are similar to shielded metal arc welding fumes, but content of hexavalent chromium is similar to metal inert gas welding fumes. These characteristics are relevant to flux of wires and $CO_2$ shielding gas.

• Journal of Environmental Science International
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• v.26 no.3
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• pp.311-324
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• 2017

To certificate change in the geochemical characteristics of surface sediments in the main stream of the Nakdong River, surface sediments from 12 sampling sites during the first and second half year (total 24 sampling sites) were collected and analyzed for grain size, ignition loss, total organic carbon and heavy metal content. Surface sediments mainly composed of sand (coarse and medium sand) and fining changed from the first half to the second half of the year. Ignition loss, total organic carbon and heavy metals content increased in the second half of the year. Some heavy metals (Zn, Ni and Cu) were found to be at the lowest effect levels according to Ontario sediment quality guidelines. Additionally, most heavy metals were found to be at the non polluted level and level I according to USEPA sediment quality standards and National Institute of Environmental Research sediment pollution evaluation standard, respectively. The enrichment factor (< 1) and index of geoaccmulation (< 0) were non polluted in the study area. The correlation analysis results showed that ignition loss, total organic carbon and heavy metal content were highly correlated with grain size. Regarding changes in geochemical characteristics of surface sediments in the study area, grain size fine and organic matter and heavy metal content increased in the second half year. Nonetheless these results indicated pollution levels that did not adversely affect the benthos.

• Korean Journal of Environmental Agriculture
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• v.25 no.3
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• pp.236-246
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• 2006

In this study, we give insight into questionable results that can be encountered in the conventional sequential extraction of heavy metals (Cd, Cu, and Zn) from soils. Objectives of this study were to determine the extraction variability of exchangeable (EXC)-metals as using six different EXC-extractants commonly accepted, and to investigate selectivity problems with carbonates bound (CAB)-metal fraction, a buffered acetate (1.0 M NaOAc; pH 5.0) extractable-metal fraction, leading to erratic results in especially non-calcareous soils. The contents of EXC-metals were markedly varied with the different extractability of various EXC-metal extractants used. The contents of EXC-Cd fraction were ranged from 2.0 to 74.3% of total Cd content in all of the metal spiked soils studied. The contents of EXC-Zn fraction extracted with the different EXC-extractants were varied with soil types, which were from 0.4 to 3.9% of total Zn in the calcareous soils, from 7.6 to 17.9% in the acidic soil, and from 13.6 to 56.8% in the peat soil. However, the contents of EXC-Cu fraction were relatively similar among the applications of different EXC-meal extractants, 0.2 to 2.1 % of total Cu, in all soils tested. Also, these varied amounts of EXC-metal fractions, especially Cd and Zn, seriously impacted the contents of subsequent metal fractions in the procedure. Furthermore, the CAB-Cd, -Cu, and -Zn fractions extracted by the buffered acetate solution were in critical problem. That is, the buffered acetate solution dissolved not only CAB-metals but also metals that bound or occupied to subsequent fractions, especially OXD-metal fraction, in both calcareous and non-calcareous soils. The erratic results of CAB-fraction also seriously impacted the amounts of subsequent metal fractions. Therefore, the conventional sequential extraction should be reconsidered theoretically and experimentally to quantify the target metal fractions or might be progressively discarded.

• 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.

• Korean Journal of Environmental Agriculture
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• v.23 no.1
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• pp.15-21
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• 2004

Objectives of this study were to monitor the distribution of heavy metals, to compare extractable heavy metal with total content and to investigate the relationships between soil physico-chemical properties and heavy metals in orchard soil. Sampling sites were 48 in Gyeonggi, 36 in Gangwon, 36 in Chungbuk, and 44 in Chungnam, Soils were collected farm form two depths, 0 to 20 and 20 to 40 cm (here after referred to as upper and lower layers) from March to May in 1998. Total contents of heavy metal in soils were analyzed by ICP-OES after acid digestion ($HNO_3$:HCl:$H_2O_2$) whereas extractable contents were measured after successive extraction of 0.1N-HCl, 0.05 M-EDTA, and 0.005 M-DTPA. Mercury was analysed by mercury atomizer. The average contents of Cd Cu, and Pb in the extractant with 0.1N-HCl at upper layer were 0.080, 4.23, and 3.42 mg/kg, respectively. As content in the extractant with 1N-HCl was 0.44 mg/kg, and total contents of Zn, Ni and Hg were 78.9, 16.1, and 0.052 mg/kg, respectively. The ratios of concentrations of heavy metals to threshold values (Cd 1.5, Cu 50, Pb 100, Zn 300, Ni 40, Hg 4 mg/ke in Soil Environmental Conservation Act in Korea (2001) were low in the range of $1/2.5{\sim}1/76.9$ in orchard soils. The ratios of extractable heavy metal to total content ranged $5.4{\sim}9.21%$ for Cd, $27.9{\sim}47.8%$ for Cu, $12.6{\sim}21.8$% for Pb, $15.8{\sim}20.3%$ for Zn, $5.3{\sim}6.3%$ for Ni, and $0.7{\sim}3.6%$ for Zn, respectively. Cu and Pb contents in 0.05 M-EDTA extractable solution were higher than those in the other extractable solution. Total contents of Cd, Ni and Ni in soils were negatively correlated with sand content but positively correlated with silt and clay contents. Ratios of extractable heavy metal to total content were negatively correlated with clay content but ai and Ni contents were positively correlated with soil pH, organic matter, and available phosphorous. Therefore, the orchard soil was safe because the heavy metal contents of orchard soil were very low as compared to its threshold value in the Soil Environmental Conservation Act. However, it need to consider the input of agricultural materials to the agricultural land for farming practices for assessment of heavy metals.

• Journal of Korean Society of Forest Science
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• v.82 no.3
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• pp.271-282
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• 1993

This study was conducted to investigate the absorbing and/or filtering capacity of woody landscape plants growing in urban and industrial regions of Seoul and Taejon. Korea. Total sulfur content and heavy metal content were analyzed in tree foliage of Pinus densiflora, Pinus koraiensis, Ginkgo biloba. Liriodendron tulipifera, Platanus occidentalis. The total sulfur content in the leaves of woody landscape plants in Seoul and Taejon were remarkably higher than those of the tree leaves in Kwangreung. The total sulfur content of deciduous trees had 2.6 times more than that of coniferous trees. the former had better absorbing capacity of $SO_2$ gas. Especially Ginkgo biloba and Platanus occidentalis were recommanded as absorption trees of $SO_2$ because sulfur content levels of them were the highest among all species and increased until tall coloration. While coniferous trees showed no changes in total sulfur content between four seasons. deciduous trees increased in sulfur during the growing season. Pb content of all species in polluted area were higher than those in unpolluted area. In polluted area, while coniferous trees had higher absorption and accumulation of Pb, deciduous trees had higher absorption of Zn. The content of Pb, Zn and Cu in needle of Pinus koraiensis were more than those of Pinus densiflora, In Pinus koraiensis and Pinus densiflora, heavy metal content in the 2nd year needle were higher than thous in the current year needle. In Pinus densiflora, Pinus koraiensis Liriodendron tulipifera and Platanus occidentalis there was a positive correlation between total sulfur and heavy metals [(Pb+Zn+Cu)/3] content.