• Journal of Environmental Science International
• /
• v.10 no.4
• /
• pp.299-304
• /
• 2001

For the remediation of the contaminated soil with heavy metals, Cd, Cr, Cu, and Pb, the reaction parameters were optimized. Tartaric acid (TA) and oxalic acid(OA) as a washing agent and recovery of metals, The optimum washing conditions of TA and OA were in the ratio of 1 : 20 between soil and acid solution during 2hr reaction under unbuffered pH solutions. At the optimized reaction conditions, the removal efficiencies were compared with that of 0.1 M HCl and ethylenediamine tetraacetic acid(EDTA). TA showed higher efficiency on the removal of Pb than that of EDTA, which established for the remediation of contaminated soil with Pb and Cd metals. The recovery of metal ions from washing solution was achieved by adding calcium hydroxide and sodium sulfide by forming the precipitation of metal hydroxide and metal slfied. Optimum amounts of sodium sulgide and calcium hydroxide were Cd = 25g/$\ell$, Cu = 5~10g/$\ell$ and Pb = 5~10g/$\ell$ for the washing solution of OA and 2~5g/$\ell$ for the washing solution of TA, respectively. The amounts of $Na_2S$ and $CA(OH)_2$ for the tartaric acid was less than that of oxalic acid.

• 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 Environmental Science International
• /
• v.26 no.6
• /
• pp.797-802
• /
• 2017

This study aimed to remove organic matter and heavy metals that could affect the recycling of soils contaminated by heavy metals, by means of electrolysis, carried out simultaneously with the leaching of the soil. To ensure better experimental equipment, a soil electrolysis apparatus, equipped with spiral paddles, was used to agitate the heavy-metal-contaminated soil effectively. The heavy-metal-contaminated soil was electrolyzed by varying the voltage to 5 V(Condition 1), 15 V(Condition 2), and 20 V(Condition 3), under the optimal operating conditions of the electrolysis apparatus, as determined through previous studies. The results showed that the pH of the electrolyte solution and the heavy-metal-contaminated soil, after electrolysis, tended to decrease with an increase in voltage. The highest removal efficiencies of TOC and $COD_{Cr}$ were 18.8% and 29.1%, 38.8% and 4.2%, and 33.3% and 50.0%, under conditions 1, 2 and 3, respectively. Heavy metals such as Cd and As were not detected in this experiment. The removal efficiencies of Cu, Pb and Cr were 4.7%, 8.3% and 2.1%, respectively, under Condition 1, while they were 42.9%, 15.2% and 22.1%, respectively, under Condition 2, and 4.7%, 23.0%, and 24.9%, respectively, under Condition 3. These results suggest that varying the voltage with the soil electrolysis apparatus for removing contaminants for the recycling of heavy-metal-contaminated soil allows the selective removal of contaminants. Therefore, the results of this study can be valuable as basic data for future studies on soil remediation.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 1998.11a
• /
• pp.81-85
• /
• 1998

In the present study, the design method of containment walls is proposed by utilizing an existing site. The selected remedy for the Source Area of Operable Unit 2 at Hill Air Force Base stipulated containment of the pure-phase trichloroethylene contamination. The in-place-mixed wall construction was selected because of the irregular topography, small area of the site, and the requirement to reach depths of greater than 90 feet below ground surface. Bench-scale compatibility studies were performed for the containment wall mix design on three commercial bentonite clays. The samples were subject to screening tests and long-term tests for evaluation of changed soil properties when exposed to the contaminated groundwater.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2004.09a
• /
• pp.20-24
• /
• 2004

The aim of this study was to analyse the cost-benefit-ratio of a soil remediation project. The target of the study was the 'Altablagerung Osnabrueck-Wueste' the largest inhabited former landfill site in Germany. The determination of benefit resulting from the soil remediation was quantified with the help of willingness-to-pay(WTP) analysis (contingent valuation method, CVM). 400 households participated in the survey. The average WTP was 6.5 Euro per household per month or 78 Euro per house-hold per year. The projected benefit generated by the remediation (consumer value) for the population in the landfill area was determined to be 0.7 million Euro per year. Factors which influence the will-ingness to pay were evaluated. The most important factors were age, garden use and the prevailing concern about personal health. A computation of the cost-benefit relationship was made on the basis of three different scenarios, which differed in terms of the projected benefits. Finally the economical efficiency of the project was determined. With a projection of 18 years and upwards the remediation of the soil is economically worthwhile.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 1999.10a
• /
• pp.23-27
• /
• 1999

After kaolin clay was compulsorily contaminated by Sr$^{2+}$ solution, the remediation characteristics by electrokinetic method were analyzed. Meanwhile, the numerical code for analysis of electrokinetic migration was developed for modelling of the soil remediation. Experimental results are as follows After 3 day remidiation under 40 voltage, the front part of experimental cell was almost decontaminated, but the behind part didn't almost be decontaminated. Accordingly, the total remediation ratio of Sr$^{2+}$ from cell soil was about 42.6 %. Also, the total Sr$^{2+}$ remediation ratio from cell soil was about 84.8 % after 6 days, and about 97.1 % after 7 days. Meanwhile, the values calculated by the developed code almost agreed with experimental values.ues.

• Korean Journal of Soil Science and Fertilizer
• /
• v.39 no.1
• /
• pp.29-37
• /
• 2006

In remediation of the contaminated soil, it requires to select at least more than two remediation technologies depending on the fate and transport phenomena through complicated reactions in soil matrix. Therefore, methodologies related to develop the integrated remediation technology were reviewed for agricultural soils contaminated with heavy metals. Pneumatic fracturing is necessary to implement deficiency because soil washing is not effective to remove heavy metals in the subsurface soil. But it needs to evaluate the characteristics such as essential data and factors of designated technology in order to effectively apply them in the site. In the remediation site, the important soil physical and chemical factors to be considered are hydrology, porosity, soil texture and structure, types and concentrations of the contaminants, and fate and its transport properties. However, the integrated technology can be restrictive by advective flux in the area which remediation is highly effective although both soil washing and pneumatic fracturing were applied simultaneously in the site. Therefore, we need to understand flow pathways of the target contaminants in the subsurface soils, that includes kinetic desorption and flux, predictive simulation modeling, and complicated reaction in heterogenous soil.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2000.11a
• /
• pp.302-306
• /
• 2000

In case of applying electrokinetic remediation, magnitude of electric current is one of major factors for estimation of contaminant transport. In practice, electric current provide determination of electric conductivity based on specimen resistance. Electric current variation is produced during Electrokinetic remediation test. Electric current is decreased by expotential function according to time in condition of constant voltage. This can be interpreted as precipitation effect by OH$^{-10}$ generation in a cathode.

• Journal of Soil and Groundwater Environment
• /
• v.6 no.4
• /
• pp.13-23
• /
• 2001

In this study, the characteristics of pH variations and contaminant distribution in soil are investigated during electrokinetic treatment for the purpose of restoring contaminated soil with heavy metal. For these objects, laboratory test for the kaolin contaminated by lead was performed. During electrokinetic treatment, lead was transported from anode to cathode. And 75% of lead removed within 80% region of the specimen. Most lead, however, that transported from anode to cathode precipitated in the vicinity of cathode compartment, thus the amount of lead removed by electroosmosis was little. Electrokinetic treatment satisfied regulation criteria of Korean Soil Environment Conservation Law within almost region of the specimen. But enhancement methods can be regarded as inevitable requisite for the cathode region.

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