• Journal of Korean Society of Environmental Engineers
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• v.27 no.10
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• pp.1072-1080
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• 2005

The extraction characteristics of heavy metals(HM) from a contaminated soil at existing lead smelters were investigated with ethylene diamine tetraacetic acid(EDTA), citrate and HCl as washing solutions. EDTA was more effective for Pb than for other heavy metals. As the mol ratio of EDTA/HM increased, the removal efficiency of heavy metals became higher. When the mol ratio of EDTA/HM approached to 6.5, it removed Pb most effectively. Citrate was effective especially in extracting Zn. The removal efficiency of HCl was comparatively high in almost all heavy metals, and at 0.3N concentration it was the highest. After soil washing process by the use of EDTA, the great part of exchangeable fractions and most of heavy metals of weakly adsorbed like carbonate fraction were extracted. For washing with citrate and HCl, four heavy metals showed the similar exchange of chemical partitioning and the exchangeable fractions of Pb which has weakly adsorbed to soil were more increased than before the process. As removal efficiency of citrate washing process depends upon the distribution of non-detrital fractions, so it can be contended that only the amount of non-detrital fractions could be removed from all the heavy metal content. EDTA and HCl could remove most of non-residual fractions in all heavy metals except Zn. As a result of EDTA washing, toxicity characteristic leaching procedure(TCLP) concentration of the processed soil met the USEPA Pb limit of 5.0 mg/L.

• Korean Journal of Veterinary Service
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• v.22 no.4
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• pp.377-383
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• 1999

Polymorphonuclear (PMN) leucocytes are fundamental importance to the body's defense mechanism and play a major role in the local and systemic reactions to infectious disease. Investigation of the physiological and pathological role of the various leucocyte subtypes in host defence mechanisms is dependent upon the isolation of adequate numbers of viable, pure leucocyte fractions. This report describes the separate frequency of PMN leucocytes both from buffy coat layer and from packed RBC layer when bovine peripheral blood was treated with various anti-coagulants such as acid-citrate-dextrose(ACD), ethyldiaminetetraacetic acid(EDTA), sodium citrate and heparin. The separate frequencies of PMN leucocytes from buffy coat layer was 60.4$\pm$9.6%(heparin), 56.8$\pm$11.8%(sodium citrate), 30.6$\pm$14.1%(ACD) and 6.2$\pm$3.7%(EDTA), in order. Those from packed RBC layer monitored with EDTA, ACD, sodium citrate and heparin was 85.0$\pm$4.7%, 84.3$\pm$5.5%, 83.8$\pm$6.5% and 76.3$\pm$7.7%, respectively. The Ficoll-hypaque(FH) density gradient method was used to remove a small part of lymphocytes and/or monocytes from leucocytes in packed RBC layer. With the result that it increased separate frequency of PMN leucocytes from EDTA(89.9$\pm$2.4%), ACD(89.5$\pm$3.6%), and sodium citrate(83.6$\pm$10.3%) than heparin(68.4$\pm$13.9%). These results indicate that the use of EDTA and ACD as anticoagulant Is suitable for the separation of PMN leucocytes from bovine peripheral blood, and that the FH density gradient method is able to increase the separate frequency of PMN leucocytes from packed RBC layer.

• Korean Journal of Animal Reproduction
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• v.22 no.4
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• pp.405-410
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• 1998

Boar semen extender Kp (Hankook Life-Science, Korea) was newly formulated by authors. This study was carried out to investigate the optimal concentrations of EDTA, Tris and citrate buffers in the Kp extender (Basic Kp) on the pH change during storage. And then the motility of boar sperm with the Kp pH stabilized (Modified Kp) was compared with those of commercial products imported into Korea such as BTS (Mini-tube. Germany; BTSg), BTS (Tri-bio, USA; BTSa) and Modena (SGI, USA). The pH values of all extenders were increased gradually with the storage days. Especially, the initial pH of Basic Kp was higher than that of BTSg, BTSa and Modena, and also higher than physiological pH of boar sperm (6.8∼7.5). When Basic Kp was added with various concentrations of EDTA (0, 0.63, 1.25 ＆ 2.37g/L), Tris (0, 0.18, 0.35, 0.71 ＆ 1.42g/L) and Citrate (0, 0.75, 0.81, 1.00, 1.25 ＆ 1.50g/L) buffers for pH down-regulation and stabilization of pH, the group added with 1.25g EDTA, 1.42g Tris and 1.00g Citrate well maintained the neutral range of pH during storage (6.88 at day1 to 7.33 at day6 in Modified Kp), Especially, the concentrations of the buffers added in Modified Kp were lower, until 1/2∼1/4 ranges, than those in Modena and other extenders. The motility of frozen-thawed boar sperm diluted with Modified Kp was significantly higher than that of Basic Kp, BTSg, BTSa and Modena (87.0% vs. 55.0∼71.0% at day1; 13.3% vs. 0∼6.3% at day6), Conclusively, Modified Kp in this experiment was kept the favorable physiological conditions in spite of low concentrations of the buffers and motility of frozen-thawed boar sperm was obtained better than that of Basic Kp and other commercial products such as BTSg, BTSa and Modena.

• Korean Journal of Veterinary Research
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• v.21 no.2
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• pp.99-104
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• 1981

A total of 251 clinical isolates (human origin, 43 strains and bovine udder origin 208 strains) of the Staphylococcus that fermented mannitol aerobically were tested for their ability to produce coagulase, DNase, and thermostable nuclease. Of these, 158 isolates coagulated human or bovine plasma, produced DNase, and thermostable, nuclease and were identified as St. aureous, 146 of which produced a 1+ to 3+ clot. The remaining 12 isolated produced a -clot in citrate treated plasma but produced 1+ to 3+ clot in ethylenedi-aminetetraacetic acid (EDTA) treated plasma. It was found that 7 coagulase positive isolates failed to produced thermostable nuclease. In these organisms, we found out of the clot formation is not by coagulase activity but utilization of citrate, because EDTA treated plasma is not coagulated. Among 93 isolates which did not coagulate citrate-or EDTA treated plasma and thermostable nuclease negative, 28 strains produced DNase were identified as St. epidermidis, and other strains were not identification further. It was found that thermostable nuclese production appears to be a consistent property of St. aureus and the test is easy to perform, is rapid became quite distinct within 2 to 4 hour, and is not influenced by as many factors and variations as the coagulase test.

• Korean Chemical Engineering Research
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• v.51 no.6
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• pp.733-738
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• 2013

Sediment contains a high fraction of organic matter, high buffering capacity, and a large portion of fine grained particles such as silt and clay, which are major barriers to remove heavy metals from sediments. In this study, a lab-scale electrokinetic (EK) technique was applied to remove heavy metals effectively from marine sediment at a constant voltage gradient of 2 V/cm. A concentration of 0.1 M of ethylenediaminetetraacetic acid (EDTA), citric acid (CA), $HNO_3$, and HCl were circulated in the cathode, and tap water was circulated in the anode. CA extracted 92.4% of Ni, 96.1% of Cu, 97.1% of Zn, and 88.1% of Pb from marine sediment. A higher voltage gradient enhanced the transport of citrate and EDTA into the sediment and, therefore, increased metal extraction from the marine sediment through a complexation reaction between metals and the chelates. Based on these results, the electrokinetic process using a high voltage gradient with EDTA and CA might be useful to extract heavy metals from marine sediment.

• Journal of Life Science
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• v.20 no.7
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• pp.1041-1046
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• 2010

Phytoextraction is a technique which uses plants to clean up metal-contaminated soils. Recently, various chelating agents were introduced into this technique to increase the bioavailability of metals in soils. Even though the technique is an economic and environment-friendly method, this cannot be applied in highly metal-contaminated areas because plants will not normally grow in such conditions. Therefore, this research focuses on identifying chelating agents which are biodegradable and applicable to highly metal-contaminated areas. Alunimum (Al) as a target metal and cysteine (Cys), histidine (His), citrate, malate, oxalate, succinate, and ethylenediamine (EDA) as biodegradable chelating agents were selected. Ethylenediamine tetraacetic acid (EDTA) was used as a comparative standard. Plants were grown on agar media containing various chelating agents with Al to analyze the effect on plant growth. His slightly diminished the inhibitory effect of Al on root growth of plants, whereas, Cys, citrate, malate, oxalate, and succinate did not show significant effects. Both EDTA and EDA strongly diminished the inhibitory effect of Al on root growth. The effect of EDA is correlated with decreased Al uptake into the plants. In conclusion, as a biodegradable chelating agent, EDA is a good candidate for highly Al-contaminated areas.

• Clinical and Experimental Pediatrics
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• v.48 no.6
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• pp.675-677
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• 2005

Pseudothrombocytopenia is usually associated with anticoagulant ethylene diaminetetraacetic acid (EDTA). The platelet clumping that occurs in EDTA-dependent pseudothrombocytopenia (EDPT) can sometimes be prevented by the use of other anticoagulants such as heparin or sodium citrate. As an alternative, we used kanamycin before or after the withdrawal of EDTA-anticoagulated blood in a 6-year-old boy with EDPT. Kanamycin used supplementarily during the differentiation of EDPT effectively prevented platelet clumping.

• Korean Journal of Environmental Agriculture
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• v.29 no.1
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• pp.61-65
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• 2010

Phytoextraction is a method of phytoremediation using plants to remediate metal-contaminated soils. Recently, various chelating agents were used in this method to increase the bioavailability of metals in soils. Even though phytoextraction is an economic and environment-friendly method, this cannot be applied in highly metal-contaminated areas because plants will not normally grow in such conditions. This research focuses on identifying chelating agents which are biodegradable and applicable to highly metal-contaminated areas. Lead (Pb) as a target metal and cysteine (Cys), histidine (His), citrate, malate, oxalate, succinate, and ethylenediamine (EDA) as biodegradable chelating agents were selected. Ethylenediamine tetraacetic acid (EDTA) was used as a comparative standard. Plants were grown on agar media containing various chelating agents with Pb to analyze the effect on root growth. Cys strongly increased the inhibitory effect of Pb on root growth of plants, while, His did not affect on it significantly. The inhibitory effect of oxalate is weak, and malate, citrate, and succinate did not show significant effects. Both EDTA and EDA diminished the inhibitory effect of Pb on root growth. The effect of EDA is correlated with decreased Pb uptake into the plants. In conclusion, as biodegradable chelating agents, EDA is a good candidate for highly Pb-contaminated area.

• Current Research on Agriculture and Life Sciences
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• v.32 no.3
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• pp.155-158
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• 2014

Phytoextraction is a technique that uses plants to remediate metal-contaminated soils. However, this technique cannot be applied in highly metal-contaminated areas, as plants cannot normally grow under such conditions. Therefore, this study investigated the introduction of various biodegradable chelating agents to increase the bioavailability of metals in highly metal-contaminated areas. Mercury (Hg) was selected as the target metal, while cysteine (Cys), histidine (His), malate, succinate, oxalate, citrate, and ethylenediamine (EDA) were used as biodegradable chelating agents. Plants were grown on agar media containing various chelating agents and Hg to analyze the effect on plant root growth. Cys and EDA were both found to diminish the inhibitory effect of Hg on plant root growth, whereas His, citrate, and ethylenediamine tetraacetic acid (EDTA) did not show any significant effects, and malate, succinate, and oxalate even promoted the inhibitory effect of Hg on plant root growth. Thus, Cys and EDA would seem to be promising biodegradable chelating agents for highly Hg-contaminated areas.

• Korean Chemical Engineering Research
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• v.43 no.1
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• pp.153-160
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• 2005

There have been large areas of soil contaminated with high levels of explosives. For this experimental work, 2,4,6-trinitrotoluene (TNT) was tested as a representative explosive contaminant of concern in both aqueous and soil samples and its removal was evaluated using three different chemical treatment methods: 1) the classical Fenton reaction which utilizes hydrogen peroxide ($H_2O_2$) and soluble iron at pH less than 3; 2) a modified Fenton reaction which utilizes chelating agents, $H_2O_2$, and soluble iron at pH 7; and 3) a Fenton-like process which utilizes iron minerals instead of soluble iron and $H_2O_2$, generating a hydroxyl radical. Using classic Fenton reaction, 93% of TNT was removed in 20 h at pH 3 (soil spiked with 300 mg/L of TNT, 3% $H_2O_2$ and 1mM Fe(III)), whereas 21% removed at pH 7. The modified Fenton reaction, using nitrilotriacetic acid (NTA), oxalate, ethylenediaminetetraacetic acid (EDTA), acetate and citrate as representative chelating agents, was tested with 3% $H_2O_2$ at pH 7 for 24 h. Results showed the TNT removal in the order of NTA, EDTA, oxalate, citrate and acetate, with the removal efficiency of 87%, 71%, 64%, 46%, and 37%, respectively, suggesting NTA as the most effective chelating agent. The Fenton-like reaction was performed with water contaminated with 100 mg/L TNT and soil contaminated with 300 mg/L TNT, respectively, using 3% $H_2O_2$ and such iron minerals as goethite, magnetite, and hematite. In the goethite-water system, 33% of TNT was removed at pH 3 whereas 28% removed at pH 7. In the magnetite-water system, 40% of TNT was removed at pH 3 whereas 36% removed at pH 7. In the hematite-water system, 40% of TNT was removed at pH 3 whereas 34% removed at pH 7. For further experiments combining the modified Fenton reaction with the Fenton-like reaction, NTA, EDTA, and oxalate were selected with the natural iron minerals, magnetite and hematite at pH 7, based on the results from the modified Fenton reaction. As results, in case magnetite was used, 79%, 59%, and 14% of TNT was removed when NTA, oxalate, and EDTA used, respectively, whereas 73%, 25%, and 19% removed in case of hematite, when NTA, oxalate, and EDTA used, respectively.