• Journal of Soil and Groundwater Environment
• /
• v.18 no.7
• /
• pp.1-11
• /
• 2013

The actively soil pollution by the toxic heavy-metals like the arsenic, cadmium, lead due to the industrialization and economic activity. The uses the electrokinetic remediation of contaminated soil has many researches against the fine soil having a small size in the on going. However, it is the actual condition which the research result that is not effective due to the low surface charge of the particle and high permeability shows in the electrokinetic remediation in comparison with the fine soil in the case of the sandy soil in which the particle size is large. In this research, the electrokinetic remediation and ultrasonic wave fetch strategy is compound applied against the sandy soil polluted by the arsenic, cadmium, and lead removal efficiency of the sandy soil through the comparison with the existing electrokinetic remediation tries to be evaluated. First of all, desorption of contaminants in soil by ultrasonic extraction in the Pre-Test conducted to see desorption effective 5~15%. After that, By conducted Batch-Test results frequency output century 200 Khz, reaction time 30 min, contaminated soil used in experiment was 500 g. Removal efficiency of arsenic, cadmium, lead are 25.55%, 8.01%, 34.90%. But, As, Cd, Pb remediation efficiency less than 1% in EK1(control group).

• Journal of Soil and Groundwater Environment
• /
• v.18 no.6
• /
• pp.8-17
• /
• 2013

The contamination of chlorinated ethenes at an industrial complex, Wonju, Korea, was examined based on sixteen rounds of groundwater quality data collected from 2009 to 2013. Remediation technologies such as soil vapor extraction, soil flushing, biostimulation, and pumping-and-treatment have been applied to eliminate the contaminant sources of trichloroethylene (TCE) and to prevent the migration of TCE plume from remediation target zones. At each remediation target zone, temporal monitoring data before and after the application of remediation techniques showed that the aqueous concentrations of TCE plume present at and around the main source areas decreased significantly as a result of remediation technologies. However, the TCE concentration of the plumes at the downstream area remained unchanged in response to the remediation action, but it showed a great fluctuation according to seasonal recharge variation during the monitoring period. Therefore, variations in the contaminant flux across three transects were analyzed. Prior to the remediation action, the concentration and mass discharges of TCE at the transects were affected by seasonal recharge variation and residual DNAPLs sources. After the remediation, the effect of remediation took place clearly at the transects. By tracing a time-series of plume evolution, a greater variation in the TCE concentrations was detected at the plumes near the source zones compared to the relatively stable plumes in the downstream. The difference in the temporal profiles of TCE concentrations between the plumes in the source zone and those in the downstream could have resulted from remedial actions taken at the source zones. This study demonstrates that long term monitoring data are useful in assessing the effectiveness of remediation practices.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 1999.10a
• /
• pp.34-38
• /
• 1999

This paper investigated remediation options for contaminated sediments with heavy metals. Twenty three sediment samples were taken from three different depths of 0.5m, 1.5m and 2.5m. The concentration of Heavy metals Cu, Pb, and Hg were measured. The concentration of copper far exceeded the Sediment Quality Guideline in U.S.A and Interim Sediment Quality Guidelines in Canada. Therefore, remediation of the sediments is requried to protect the benthos. Two remediation options were suggested : dredging of the organic sediments as deep as about 85cm followed by surface covers with clean soil, and in-situ stabilization of tile sediments using lime or cement followed by surface cover with clean soil.

• Membrane and Water Treatment
• /
• v.11 no.3
• /
• pp.189-193
• /
• 2020

In this study, electrokinetic remediation equipment was used to remove cesium (Cs) from clay soil and waste solution was treated with sorption process. The influence of electrokinetic process on the removal of Cs was evaluated under the condition of applied electric voltage of 15.0-20.0 V. In addition to monitoring the Cs removal, electrical current and temperature of the electrolyte during experiment were investigated. The removal efficiency of Cs from soil by electrokinetic method was more than 90%. After electrokinetic remediation, Cs was selectively separated from soil waste solution using sorbents. Various adsorption agents such as potassium nickel hexacyanoferrate (KNiHCF), Prussian blue, sodium tetraphenylborate (NaTPB), and zeolite were compared and KNiHCF showed the highest Cs removal efficiency. The Cs adsorption on KNiHCF reached equilibrium in 30 min. The maximum adsorption capacity was 120.4 mg/g at 0.1 g/L of adsorbent dosage. These results demonstrated that our proposed process combined electrokinetic remediation of soil and waste solution treatment with metal ferrocyanide can be a promising technique to decontaminate Cs-contaminated fine soil.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2001.04a
• /
• pp.226-229
• /
• 2001

For volume reduction of the wastewater generated on washing the soil contaminated with cobalt, recycling and reuse experiments of the wastewater were executed. Also. the soil remediation efficiency by repetitive washing with fresh citric acid was analyzed. The soil around TRIGA was sampled for the experiment. Results of recycling experiment by replacement-precipitation method were as follows. The remediation efficiency of 1st recycling wastewater was 97% and that of 2nd recycling wastewater was 94%. Also, To obtain remediation efficiency over than 90%, the 5th repetitive washing with fresh citric acid was needed.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2003.09a
• /
• pp.217-221
• /
• 2003

Variation of decision variables for optimal remediation using the pump-and-treat method is examined to estimate the effect of the degree of concentration constraint. Simulation-optimization method using genetic algorithm is applied to minimize the total pumping volume. In total volume minimization strategy, the remediation time increases rapidly prior to significant increase in pumping rates. When the concentration constraint is set severer, the more wells are required and the well on the down-gradient direction from the plume hot-spot gives more efficient remediation performance than that on the hot-spot position. These results show that the more profitable strategy for remediation can be achieved by increasing the required remediation time than raising the pumping rate until the time reaches a certain limitation level. So, the remediation time has to be considered as one of the essential decision variables fer optimal remediation design.

• Journal of Korea Soil Environment Society
• /
• v.4 no.2
• /
• pp.55-62
• /
• 1999

The solvent flushing apparatus for soil remediation was designed. After the soil around nuclear facilities was sampled and compulsorily contaminated by Co, the characteristics remediated by solvent flushing were analyzed. Meanwhile, the nonequilibrium sorption code was developed for modelling of the soil remediation by solvent flushing, input parameters needed for modelling were measured by laboratory experiment. Experimental results are as follows : The soil around nuclear facilities belongs to Silt Loam including a lot of silt and sand. When water was used as a solvent, the higher was the hydraulic conductivity. the higher the efficiency of soil remediation was. The values calculated by the nonequilibrium sorption code agreed with experimental values more exactly than the values calculated by the equilibrium sorption code. When EDTA solution was used as a solvent. the soil remediation efficiency by EDTA solution showed higher than that by water.

• Journal of the Korean Geosynthetics Society
• /
• v.5 no.2
• /
• pp.1-8
• /
• 2006

The properties of contaminated soil, contaminants and elapsed time are important considering factors to in-situ soil remediation. Gabr et. al. (1996) derived the solution equation of contaminant concentration ratio as initial one ($C/C_0$) with time and spatial changes in contaminated area which are embedded with vertical drains. The contaminant concentration ratio ($C/C_0$) is analyzed with time and spatial changes as varying the effective diameter, porosity, shape factor, density of contaminated soil, temperature in ground, unit weight and viscosity of contaminants by using FLUSH1 model modified from FLUSH. Results from numerical analysis indicate that the most important factor to the in-situ soil remediation in vertical drain system is the effective diameter of contaminated soil. It also shows that the next important factors are the viscosity of contaminants, porosity of soil, shape of soil, temperature in ground, unit weight of contaminants and density of soil, in order. However, the others except the effective diameter of contaminated soil are insignificant to the soil remediation.

• Journal of the Korean Society for Railway
• /
• v.3 no.3
• /
• pp.101-108
• /
• 2000

In this study, we tested hybrid pilot system combined with soil vapor extraction and bioventing methods on the contaminated railroad soil. So, we found out the remediability and operating conditions. Air permeability(k) and gas phase(O$_2$/CO$_2$/VOCs) level trend are very important to determine the remediation rate of the contaminated sites. Throughout hybrid pilot test on different conditions, the range of air permeability(k) was 1985∼1194 darcy. The tests results in hybrid system was appropriate on this test sites, and the suitable injection air flow rate was 3.5㎥/hr. So, we suggested a basic data for the remediation and management of contaminated railroad soil.

• Journal of Soil and Groundwater Environment
• /
• v.10 no.2
• /
• pp.1-11
• /
• 2005

This study applied EK method to remediate contaminated soil by lead (Pb), tried increasing efficiency of remediation using adsorbent (apatite and zeolite) as enhanced EK remediation method to overcome the limit of traditional EK remediation method. Adsorption tests on Pb were practiced to extract EK, making different concentration of contaminated soil, voltage condition, operating time etc., transferring Pb-ion into the position of adsorbent, then tried immobilization. On this results, the efficiency of remediation is different on its test conditions. In addition, the efficiency of remediation was not only improved by adding electrode revεrsal and install position of adsorbent but also satisfied TCLP regulation of EPA in USA through the whole sample range. Finally, absorption and immobilization capacity of apatite and zeolite proved on its excellence and confirmed the possibility of application of apatite and zeolite as enhanced EK remediation method.