• Journal of Environmental Science International
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• v.26 no.6
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• pp.797-802
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• 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 Agricultural Engineers Conference
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• 2003.10a
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• pp.183-186
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• 2003

This study was conducted to evaluate effects by adding oil to clay soil and influences of remained oil in soil as time elapsed. Unconfined compression test and direct shear test were performed to analyze strength properties of contaminants in clayey soil. As a results of $q_u$ test for kerosene and diesel contaminated clayey soil indicate that were decreased from near 5% oil content rapidly and the declination of strength were blunt as oil content over 10%. The cohesions(c) and internal friction angle(${\psi}$) of kerosene contaminated clayey soil were not varied as quantities of kerosene in clayey soil increased. In the case of diesel contaminated clayey soil, the cohesions(c) were decreased and the internal friction angle(${\psi}$) were increased.

• Journal of The Korean Society of Grassland and Forage Science
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• v.42 no.2
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• pp.108-113
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• 2022

Arsenic (As) uptake and accumulation from agricultural soil to rice vary depending on the soil environmental conditions such as soil pH, redox potential, clay content, and organic matter (OM) content. Therefore, these factors are important in predicting changes in the uptake and accumulation of As in rice plants. Here, we studied the chemical properties of As-contaminated and/or rice straw compost (RSC)-treated soils, the growth responses of RSC-applied rice plants under As-contaminated soils, the changes in As content of soil, and the relationship between As uptake and accumulation from the RSC-treated soils to the rice organs under As-contaminated soils. Rice plants were cultivated in 30 mg kg^-1 As-contaminated soils under three RSC treatments: 0 (control), 12, and 24 Mg ha^-1. No significant differences were indicated in the chemical properties of pre-experimental (before transplanting rice seedling) soils, with the exception of EC, OM, and available P₂O₅. As the treatment of RSC under 30 mg kg^-1 As-contaminated soils increased, EC, OM, and available P₂O₅ increased proportionally in soil. Increased soil RSC under As-contaminated soils increased shoot dry weight of rice plants at harvesting stage. As content in roots increased proportionally with RSC content, whereas As content in shoots decreased under As-contaminated soil at all stages of rice plants. Nevertheless, As accumulation were significantly decreased in both roots and shoots of RSC-treated rice plants than those in the plants treated without RSC. These results indicate that the use of RSC can mitigate As phytotoxicity and reduce As accumulation in rice plants under As-contaminated soils. Therefore, RSC can potentially be applied to As-contaminated soil for safe crop and forage rice production.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.04a
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• pp.347-350
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• 2002

Arsenic speciation changes between As(V) and As(III) are subject to changes in accordance with redox conditions in the environment. It is common to find contaminated sites associated with mixed wastes including both organic pollutants and heavy metals. We conducted microcosm experiment under hypothesis that the co-disposed organic pollutants would influence on the arsenic forms and concentrations, via degradation of the organic pollutants and the consequent impact on the redox conditions in soil. Artificially contaminated soil samples were run for 40 days with control samples without artificial contamination. We noticed arsenic in the contaminated soil showed different behaviour compared with the arsenic in the control soil. The findings indicate degradation of organic pollutants in the contaminated soil influenced on the arsenic speciation and concentrations. A further work is needed to understand the process quantitatively. However, we could confirm that degradation of organic pollutants can influence on the abiotic processes associated with geochemical reactions in contaminated soil. Degradation of organic pollutants can increase the mobility and toxicity of arsenic in soil and sediment by changing redox conditions in the geological media and subsequently from As(V) to As(III).

• Proceedings of the Korean Geotechical Society Conference
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• 2005.10a
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• pp.373-381
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• 2005

The permeability of contaminated soil and elapsed time are important considering factors to in-situ soil remadiation. 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 embedded with vertical drains. The contaminant concentration ratio (C/$C_0$) is analyzed with time and spatial changes in three different permeability areas which are $k=l.0{\times}10^{-5,}$ $l.0{\times}l0^{-6,}$ $l.0{\times}l0^{-7}\;_{m/s}$ by using the Gabr's equation. Results from numerical analysis indicate that the ratio (C/$C_0$) decreases as the elapsed time increases in every point, however, remediation efficiency decreases as the analyzing point is far from injection well to extraction one and is deeper from top level of contaminated area. And also it decreases as the permeability of contaminated area decreases. Especially, the lower permeability of contaminated area effects directly on the soil remediation, in this research, under condition which the permeability of contaminated area is $l.0{\times}l0^{-7}\;_{m/s}$, the maximum time needed to attain 90% clean up level ($t_{90}$) is 65,690 hours(7.5 years), it takes so much time to clean the low permeability contaminated soil.

• Journal of Soil and Groundwater Environment
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• v.21 no.4
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• pp.10-19
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• 2016

Land contamination has emerged as a major environmental and land management issue over the last decade. Although the importance of contaminated land management was continuously increased and many developed countries tried to make advanced contaminated land register system, current Korea soil regulations and policies have not been considered yet. This study analyzed existing or developing contaminated land register system from various countries to suggest implications of environmental decision support. Through this study, the introduction of contaminated land management system as creating a new system in Korea needs to considerable review to the following in order to achieve the objective through a effective adoption and operation (1) we need to establish contaminated land register system by providing a proper legal basis before the imposition of data collection, investigation, and management, (2) sufficient examination is required to identify scope of information disclosure and criteria, contents, and subjects of items from contaminated land register system.

• Journal of Soil and Groundwater Environment
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• v.26 no.5
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• pp.9-19
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• 2021

This study evaluated the feasibility of combined use of physical separation and soil washing to remediate heavy metals (Pb and Cu) contaminated soil in a military shooting range. The soils were classified into two types based on the level of heavy metal concentrations: a higher contaminated soil (HCS) with Pb and Cu concentrations of 6,243 mg/kg and 407 mg/kg, respectively, and a lower contaminated soil (LCS) with their concentrations of 1,658 mg/kg and 232 mg/kg. Pb level in both soils exceeded the regulatory limit (700 mg/kg), and its concentration generally increased with decreasing soil particle size. However, in some cases, Pb concentrations increased with increasing soil particle size, presumably due to the presence of residues of bullets in the soil matrix. As a pretreatment step, a shaking table was used for physical separation of soil to remove bullet residues while fractionating the contaminated soils into different sizes. The most effective separation and fractionation were achieved at vibration velocity of 296 rpm/min, the table slope of 7.0°, and the separating water flow rate of 23 L/min. The efficiency of ensuing soil washing process for LCS was maximized by using 0.5% HCl with the soil:washing solution mixing ratio of 1:3 for 1 hr treatment. On the contrary, HCS was most effectively remediated by using 1.0% HCl with the same soil:solution mixing ratio for 3 hr. This work demonstrated that the combined use of physical separation and soil washing could be a viable option to remediate soils highly contaminated with heavy metals.

• Journal of Soil and Groundwater Environment
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• v.15 no.1
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• pp.19-28
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• 2010

Considering six screen matrix to select an optimum remediation method for the Kunsan military base contaminated with petroleum oil, the following order was obtained: landfarming > biopile > soil washing > thermal desorption = incineration. When the landfarming method was applied for the remediation of 2,250 $m^3$ soil contaminated with petroleum oil ranging from 500 to 2,404 mg/kg as TPH, contamination level decreased below target concentration 450 mg/kg after 20~42 days depending on the initial contamination. From the evaluation of case studies of landfarming, it is suggested that ratty-truss or single-arch structure is suitable in the landfarming plant for the treatment of large-scale contaminated soil requiring long period of remediation. But, vinyl-house structure is suitable in the landfarming plant for the treatment of small-scale contaminated soil requiring short period of remediation. Therefore vinyl-house structure is recommended in the remediation of contaminated soil less than 5,000 $m^3$ requiring within 1 year of remediation period but ratty-truss or single-arch structure is recommended for the remediation of contaminated soil more than 5,000 $m^3$.

• Journal of Soil and Groundwater Environment
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• v.13 no.2
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• pp.30-35
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• 2008

In this study, the feasibility of soil washing, chemical oxidation and sonication was investigated to treat lubricantcontaminated railroad soil. Tergitol, a non-ionic surfactant, was used as a washing agent with or without iso-propyl acohol as a cosolvent. However, it was not effective to remove lubricant from soil even though tergitol was the most effective washing agent for diesel-contaminated soil. The cosolvent reduced the overall washing efficiency. Chemical oxidation removed 30% of lubricant from contaminated soil. Soil washing after chemical oxidation extracted additionally 16-17% of lubricant. Sonication enhanced-soil washing showed enhanced overall efficiency of soil washing. Lubricant-contaminated soil should be remediated by the other technology used for diesel-contaminated soil.

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