• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.6 no.1
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• pp.1-9
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• 2008

This study examined the effect of an electrokinetic-flushing remediation for a soil of a high permeability. The soil was sampled from the site around a research atomic reactor which had high hydro-conductivities due to a high content of sand in the soil. The flow rate of the washing reagent was fast at the beginning but it was reduced as time lapsed. In the case of using citric acid as a washing reagent, the flow rate was fastest, 78.7 ml/day. The removal efficiencies of $Co^{2+}$ and $Cs^+$ from a soil cell with acetic acid were the highest, which were 95.2% and 84.2% respectively. The soil waste-solution volume generated from the electrokinetic remediation was reduced to about 1/20 of that from the soil washing remediation. Meanwhile, the electrokinetic-flushing method enhanced the removal efficiencies of $Co^{2+}$ and $Cs^+$ from the soil by about 6% and 2% respectively, compared to those by the electrokinetic method. Consequently, it was found that the electrokinetic-flushing method was more effective for the remediation of a soil with a high permeability.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.09a
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• pp.302-305
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• 2003

The electrokinetic remediation tests for natural soil contaminated by lead are performed on unsaturated conditions, in which the degree of saturation is controlled through the changes in water content and the constant unit weight. At the degree of saturation of 70% the small acid range and electrical potential is developed. The changes in the water content are little above the saturation of 90%. But it is increased by 1.7 times at the degree of saturation of 70%. Finally, the efficiency of extraction is improved at 70% than 100%.

• Journal of Soil and Groundwater Environment
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• v.15 no.5
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• pp.1-7
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• 2010

Electrokinetic technology was applied to remediate Cu, Pb and As-contaminated paddy soil. Removal of metal is highly dependent on the processing fluid during electrokinetic treatment. Tap water, NaOH, $HNO_3$, $Na_2EDTA$, and citric acid were evaluated as the processing fluids to enhance metal removal. Cu and Pb were transported toward cathode, however, it did not removed from soil section, while 56.6% of As was removed at a acidic condition. The strong acidic condition with nitric acid as a processing fluid enhanced the desoprtion of As from soil surface. However, longer operation time is needed to get the higher removal of Cu and Pb, and the acidification of soil after electrokinetic treatment should be solved.

• Nuclear Engineering and Technology
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• v.34 no.1
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• pp.1-8
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• 2002

After kaolin clay was artificially contaminated with Co$^{2+}$ ion, the remediation characteristics were analyzed by the electrokinetic method. Ethanoic buffer was injected in the soil column and $CH_3$COOH was continuously inputted to the cathode reservoir to restrain the pH increase. Since the pH of the cathode side of the soil column was 4.0 initially and increased to only 6.5 after remediation for 43.6 hours, precipitate, Co(OH)$_2$, was not formed in the column. The effluent rate increased with the passage of time and Co$^{2+}$ removal in the column at the initial time were mainly controlled by ion migration. 13.1% of the total amount of Co$^{2+}$ in the soil column was removed in 10 hours, 46.8% of the total Co$^{2+}$ in 20.8 hours, 71.7% of the total Co$^{2+}$ in 30.1 hours, and 94.6% of the total Co$^{2+}$ in 43.6 hours. Meanwhile, residual concentrations in the column calculated by the developed model were similar to those by experiment. experiment.

• Journal of Soil and Groundwater Environment
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• v.13 no.6
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• pp.17-22
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• 2008

The feasibility of acid-enhanced electrokinetic remediation on zinc and nickel-contaminated soil was investigated in the laboratory. Simple extraction efficiency using 1M HCl was 24% for Zn and 9% for Ni, as a result, the acid washing is not effective to remove Zn and Ni from the soil. The effiencey of normal electrokinetic treatment during 28 days was less than simple soil washing. Catholyte circulation with a strong acid enhanced dramatically the removal of Zn and Ni and pretreatment of soil with acid increased more the removal. Based on the result, acid-enhanced electrokinetic remediation is effective to remove Zn and Ni from the contaminated soil.

• Journal of Soil and Groundwater Environment
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• v.8 no.1
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• pp.1-8
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• 2003

Three different surfactants, APG, Brij30, and SDS, were tested to study the characteristics of sorption on soil surfaces, washing ability, biodegradability, and electrokinetic removal. Kaolinite and phenanthrene were selected as a model soil and a representative HOC, respectively. Phenanthrene was sorbed on kaolinite up to 2,200 mg/kg dry soil. The APG, Brij30, and SDS were sorbed on soil to 40, 7, and 4g/kg soil, respectively. The washing ability of phenanthrene was in order of Brij30＆gt;SDS＆gt;APG. The biodegradability tested with sludge was in order of APG＆gt;Brij30＆gt;SDS. In the electrokinetic test, the highest removal efficiency was obtained with APG that exhibited the highest electroosmotic flow. To increase the removal efficiency of HOC in the electrokinetic remediation, the most important factor was the selection of surfactant which maximized the electroosmotic flow.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2001.09a
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• pp.191-194
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• 2001

The electrokinetic apparatus for remediation of the soil contaminated with Cs$^{+}$was designed. After kaolin clay was compulsorily contaminated by Cs$^{+}$ solution, the remediation characteristics by electrokinetic method were analyzed. After remediation experiment, the pH of the cathode side of the soil column was increased to 12.7 due to the generation of OH in cathode reservoir, but no hydroxide cesium form in the cathode side. Effluent rate from the cathode almost was constant and cesium concentration of effluent decreased with time passage. The 49% of a total of Cs$^{+}$ in the column was decontaminated for 0.4 day, the 72% of a total of Cs$^{+}$ in the column was decontaminated for 0.8 day, the 83% of a total of Cs$^{+}$ in the column was decontaminated for 1.2 days, the 89% of a total of Cs$^{+}$ in the column was decontaminated for 1.6 days, and the 93% of a total of Cs$^{+}$ in the column was decontaminated for 2.1 day Meanwhile, the predicted values of residual concentration by the developed model were quite similar to those obtained from experiments.m experiments.

• Proceedings of the KSEEG Conference
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• 2007.04a
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• pp.37-39
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• 2007

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• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.09a
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• pp.72-75
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• 2004

The potential of electrokinetic (EK) technology has been successfully demonstrated for the remediation of heavy metal contaminated fine-grained soils through laboratory scale and field application studies. Arsenic contamination in soil is a serious problem affecting both site use and groundwater quality. The EK technology was evaluated for the removal of arsenic from two soil samples: kaolinite clay artificially contaminated with arsenic and arsenic-bearing tailing soil taken from the Myungbong (MB) mining area. The effect of cathodic electrolyte on the process was investigated using three different types of electrolyte: deionized water (DIW), potassium phosphate (KH$_2$PO$_4$) and sodium hydroxide (NaOH). The result of experiments on the kaolinite clay shows that the potassium phosphate was most effective in extracting arsenic, probably resulting from anion exchange of arsenic species by phosphate. On the contrary, the sodium hydroxide seemed to be most efficient in removing arsenic from the tailing soil, and it is explained by the fact that sodium hydroxide increased the soil pH and accelerated ionic migration of arsenic species through increase in desorption and dissolution of arsenic species into pore water.

• Journal of Soil and Groundwater Environment
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• v.12 no.3
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• pp.23-28
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• 2007

A number of batch isotherm and electrokinetic experiments were conducted in order to investigate the migration of zinc and its removal efficiency during electrokinetic soil processing. Sorption and desorption characteristics of zinc spiked kaolin clay have been examined by comparison with electrically induced desorption and precipitation occurring in the anode and cathode regions, respectively. The removal efficiency of zinc under the applied voltage gradient of 300 V/m was found to be up to approximately 80 % within 4 hours of the electrokinetic treatment. The study is significant with respect to the remediation of contaminated areas.