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

• Geotechnical Engineering
• /
• v.13 no.6
• /
• pp.123-138
• /
• 1997

Electroosmotic tests were performed on saturated marine clay specimens contaminated with lead to investigate the efficiency of the electrokinetic technique for removal of heavy metals from the cohesive soils. For this purpose, testing program included variable conditions such as the concentration of lead (500, 5, 000, 50, 000mg/kg), the level of electrical current (10, 50, 100 mA), operating duration (5, 15, 30days), and the application of three dirtferent chemicals for enhancement in efficiency. The pH of inflow and outflow, electroosmotic flow and electrical conductivity during the test, and the pH and the concentration of lead across the specimen after the test are presented. Test results came to the conclusion that the electrokinetic technique was very effective to remove heavy metals such as lead from the contaminated cohesive soil. Adding ecetic acid at the cathod to dissolve the procipitates of lead hydroxide as found to be effective for the enhancement of the efficiency in remediation.

• Journal of Soil and Groundwater Environment
• /
• v.18 no.1
• /
• pp.6-15
• /
• 2013

The influence of processing fluids and electrode spacing on the electrokinetic process was evaluated to remediate As-, Cu-, Pb-contaminated soil. Single and mixture of sodium citrate, EDTA and NaOH was used to investigate the metal extraction. EDTA for washing reagent showed the highest removal efficiency. Based on the extraction result, the electrode spacing (20, 40, 60 cm) on the electrokinetic process was investigated to remove the multi-metals from soil. The highest removal was observed at the experiment with 60 cm of electrode spacing, however, the correlation between electrode spacing and removal of metals was not clear. The electrode spacing influenced the amount of accumulated electro-osmotic flow. BCR sequential extraction showed that electrokinetic process removed the fractionation of metals bound to Fe-Mn oxyhydroxide.

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

• Analytical Science and Technology
• /
• v.10 no.5
• /
• pp.325-331
• /
• 1997

Among various CE separation methods, micellar electrokinetic capillary chromatography(MECC) method using sodium dodecylsulfate(SDS) provides rapid and accurate separation of organic explosive constituents with easy. The running buffer was composed with 2.5 mM borate and 25mM SDS(pH 8.5). Addition of 1M urea and 10% organic modifiers (acetonitrile, methanol and ethanol) improves the resolution of adjacent explosive constituents. When 15 explosive constituents were developed in MECC, most constituents were separated successively while RDX/TNB and DNN/DEP were not, and detection limits of separated compounds are in range of 1 to 4 ppm.

• Geotechnical Engineering
• /
• v.14 no.4
• /
• pp.77-90
• /
• 1998

To study the improvement of soft marine clay from southern coast of Korea under theelectroosmosis and electrophoresis conditions, several electrokinetic tests were carried out in electrokinetic(E/K) cell. In electroosmosis tests, various treatment times and current densities were used to investigate the strengthening effect under different conditions. From these tests results, it may be noted that electroosmotic strengthening of soft marine clay was effective in proportion to unit power consumption, current density and treatment time. However, electrophoresis method was not effective for thin soil.

• Proceedings of the IEEK Conference
• /
• 2001.10a
• /
• pp.91-96
• /
• 2001

Restoration of contaminated soils to an environmentally acceptable condition is important. One of the newer techniques in soil remediation is a method based on electrokinetic phenomena in soils. The technology uses electricity to affect chemical concentrations and water flow through the pores of soils. An important advantage of electrokinetic soil remediation over other in-situ processes such as soil flushing is the capability of control over the movement of the contaminants. Because the migration of the contaminants is confined by the electric field, there is little dispersion outside the treatment zone. Furthermore, the process is effective for soils with low and variable permeability. In the present study, the distributions of cadmium in the electrokinetic processing of kaolinite under the condition of constant applied voltage are investigated. Cadmium accumulates near the cathode without reducing the diffusion of hydroxide ion into the soil. In keeping the catholyte pH at neutrality, cadmium migrates toward the cathode without any accumulation of cadmium near the cathode and is successfully removed at the cathode reservoir. It was also found that the progress of electrokinetic processing of cadmium could be gasped to a certain extent by monitoring the local voltage and the current density.

• Journal of Soil and Groundwater Environment
• /
• v.7 no.1
• /
• pp.15-24
• /
• 2002

Nowdays electrokinetic technique has been applied to supply nutrients and TEAs for in-situ bioremediation. However the Injection characteristics under electrical field have not been examined in various soil types. Therefore, The characteristics of electrokinetic injection into kaolinite and sand are investigated. During the 17 d of processing, There was a gradual increase in ammonium (nutrient) concentration from the anode compartment. However the ammonium concentration at the cathode increased beyond that at the anode in sand. A relatively constant profile of sulfate (TEA) was achieved specifically, the final sulfate concentration in each specimen were different. When EK injection technique is implemented in field, the most important consideration should be an assessment of the injection characteristics with respect to the soil types.

• Environmental Engineering Research
• /
• v.24 no.3
• /
• pp.456-462
• /
• 2019

Hydrocarbon contamination is among the most challenging problems in soil remediation. Electrokinetic method can be a promising method to remediate hydrocarbon-contaminated soils. Electrokinetic method consists of different transport phenomena including electro-migration, electrophoresis, and electroosmotic flow. Electroosmotic flow is the main transport phenomenon for hydrocarbon removal in soil porous media. However, the main component of hydrocarbons is the hydrophobic organic which indicates low water solubility; therefore, it makes the electroosmotic flow less effective. The objective of the present study is to enhance electrokinetic remediation of diesel-contaminated silty sand by increasing the solubility of the hydrocarbons in the soil and then increase the efficiency. For this purpose, sodium dodecyl sulfate (SDS) was used as a catholyte. In this content, SDS 0.05 M was used as catholyte and $Na_2SO_4$ 0.1 M was used as an anolyte. Low (1 V/cm) and high (2 V/cm) voltage gradients were used in periodic and continuous forms. The best removal efficiency was observed for high voltage gradient (2 V/cm) in a periodic form, which was 63.86. This result showed that a combination of periodic voltage application in addition to the employment of SDS is an effective method for hydrocarbon removal from low permeable sand.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2003.03a
• /
• pp.641-646
• /
• 2003

In this study, a series of electrokinetic(EK) remediation experiments are carried out under the different degree of saturation for contaminated soil with lead. for constant electrical potential, the final current of all the sample represents the similarity to steady-state value of 5∼7mA. Under conditions of all the degree of saturation the anode reservoir becomes acidic(pH as low as 3) while the cathode reservoir is basic(pH as high as 12). But pH changes in the sample is a little and decontamination efficiency is the low.