• Journal of the Korean GEO-environmental Society
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• v.11 no.11
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• pp.63-75
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• 2010

There are several remediation technologies for heavy metal contaminated soils but increasing cost limits the application of the technology if the contaminated area is large. Therefore, stabilization, which blocks the release of heavy metals or makes slow the release, is one of the applicable technology for the heavy metal contaminated soil. Current study is an applicability test for a smelter area with various stabilizer such as magnetite, hematite, zeolite-A, zeolite-X, zeolite-Y, zinc oxide, calcium oxide, carbon trioxide, manganese oxide, manganese dioxide, fish bone, sodium phosphate. The soil contaminated with arsenic, lead, copper, nickel, and zinc could not be stabilized only one stabilizer which is known to have stability for certain metal. Many of the stabilizer works for a few metal but not all of the heavy metal. In several cases, stabilizers increase the release of the other metals while they stabilize some metals. In general, the stabilizing efficiency was increased with time. For Ni, Pb, calcium oxide, carbon trioxide, manganese oxide had good stabilizing effect in water extractable portion. For Cu, manganese oxide, zeolite showed good results especially in the exchangeable portion of the sequential extraction. For As, magnetite had good ability but most of the metal oxide which showed good result for other heavy metals increased with the release of As. Current study suggest that multiple stabilizers are needed for the contaminated soil and dose of the stabilizer and stabilizing time should be carefully considered for the soil contaminated with various metals.

• Journal of Korea Soil Environment Society
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• v.5 no.1
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• pp.13-23
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• 2000

The effects of operating condition of soil vapor extraction system and the characteristics of site on the remediation of oil contaminated soil were investigated. Thorough investigation showed that the site was contaminated with gasoline leaked from underground storage tank and the maximum concentration of BTEX and TPH were 1,081 ppm and 5,548 ppm respectively. The leaked gasoline were diffused to 6m deep and the area and volume of the polluted soil were assumed to 170$m^2$ and 1,000$\textrm{m}^3$respectively. The site were consisted of three different vertitical layers, the top reclaimed sandy soil between the earth surface and 3~4m deep, middle silty sand between 3~4m and 6m deep, and the bottom bedrock below the 6m deep. The air pemeability of soil was measured to 1.058-1.077$\times$10$^{-6}$ $\textrm{mm}^2$ by vacuum pump tests. The groundwater which level was 3~4m deep was observed in some areas of this site. The soil vapor extraction system which had 7.5 HP vacuum pump and 8 extraction wells was constructed in this site and operated at 8 hrs/day for 100 days. The BTEX was removed with above 90% efficiency where no groundwater and silty sand were observed. On the contrary, the efficiency of BTEX and TPH were dramatically decreased where groundwater and silty sand were observed. The flow rate of soil air induced by soil vapor extraction system was reduced in deeper soil.

• Journal of Soil and Groundwater Environment
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• v.18 no.1
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• pp.129-136
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• 2013

This research was conducted to investigate effects of acid buffering capacity and soil component in treatment of phenanthrene using electrokinetic-Fenton process. In Hadong clay of high acid buffering and low iron oxide content, it was difficult to oxidize phenanthrene due to shortage of iron catalyst and scavenger effect of carbonate minerals. The desorbed phenanthrene conductive to Fenton oxidation was transported toward cathode by electroosmotic flow. However, in Youngdong illitic clay, oxidation of phenanthrene near anode readily occurred compared to Hadong clay due to high iron content and low acid buffering capacity.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2001.09a
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• pp.61-64
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• 2001

In the remediation of contaminated soil by electrokinetic process, transport characteristics of contaminants are major factors. Pb is highly fixed to entire soil and not moved readily. High concentration of Cd was analyzed in the cathodic section but anodic section's concentration was lower than initial concentration. Although the Cd had high treatment effect, 50% of total mass was concentrated in cathodic section and was not flowed out readily. Most of transported Cd may be adsorbed in the cathodic side soil due to increased pH at adjacent to catholyte.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2000.11a
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• pp.44-63
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• 2000

Situated close to Heathrow Airport, and adjacent to the M4 and M25 Motorways, the site at Axis Park is considered a prime location for business in the UK. In consequnce two of the UK's major property development companies, MEPC and Redrew Homes sought the expertise of Intergeo to remediate the contaminated former industrial site prior to its development. Industrial use of the twenty-six hectare site, started in 1936, when Hawker Aircraft commence aircraft manufacture. In 1963 the Firestone Tyre and Rubber Company purchased part of the site. Ford commenced vehicle production at the site in the mid-1970's and production was continued by Iveco Ford from 1986 to the plant's decommissioning in 1997. Geologically the site is underlain by sand and gravel, deposited in prehistory by the River Thames, with London Clay at around 6m depth. The level of groundwater fluctuates seasonally at around 2.5m depth, moving slowly southwest towards local streams and watercourses. A phased investigation of the site was undertaken, which culminated in the extensive site investigation undertaken by Intergeo in 1998. In total 50 boreholes, 90 probeholes and 60 trial pits were used to investigate the site and around 4000 solid and 1300 liquid samples were tested in the laboratory for chemical substances. The investigations identified total petroleum hydrocarbons in the soil up to 25, 000mg/kg. Diesel oil, with some lubricating oil were the main components. Volatile organic compounds were identified in the groundwater in excess of 10mg/l. Specific substances included trichloromethane, trichloromethane and tetrachloroethene. Both the oil and volatile compounds were widely spread across the site, The specific substances identified could be traced back to industrial processes used at one or other dates in the sites history Slightly elevated levels of toxic metals and polycyclic aromatic hydrocarbons were also identified locally. Prior to remediation of the site and throughout its progress, extensive liaison with the regulatory authorities and the client's professional representatives was required. In addition to meetings, numerous technical documents detailing methods and health and safety issues were required in order to comply with UK environmental and safety legislation. After initially considering a range of options to undertake remediation, the following three main techniques were selected: ex-situ bioremediation of hydrocarbon contaminated soils, skimming of free floating hydrocarbon product from the water surface at wells and excavations and air stripping of volatile organic compounds from groundwater recovered from wells. The achievements were as follows: 1) 350, 000m3 of soil was excavated and 112, 000m3 of sand and gravel was processed to remove gravel and cobble sized particles; 2) 53, 000m3 of hydrocarbon contaminated soil was bioremediated in windrows ; 3) 7000m3 of groundwater was processed by skimming to remove free floating Product; 4) 196, 000m3 of groundwater was Processed by air stripping to remove volatile organic compounds. Only 1000m3 of soil left the site for disposal in licensed waste facilities Given the costs of disposal in the UK, the selected methods represented a considerable cost saving to the Clients. All other soil was engineered back into the ground to a precise geotechnical specification. The following objective levels were achieved across the site 1) By a Risk Based Corrective Action (RBCA) methodology it was demonstrated that soil with less that 1000mg/kg total petroleum hydrocarbons did not pose a hazard to health or water resources and therefore, could remain insitu; 2) Soils destined for the residential areas of the site were remediated to 250mg/kg total petroleum hydrocarbons; in the industrial areas 500mg/kg was proven acceptable. 3) Hydrocarbons in groundwater were remediated to below the Dutch Intervegtion Level of 0.6mg/1; 4) Volatile organic compounds/BTEX group substances were reduced to below the Dutch Intervention Levels; 5) Polycyclic aromatic hydrocarbons and metals were below Inter-departmental Committee for the Redevelopment of Contaminated Land guideline levels for intended enduse. In order to verify the qualify of the work 1500 chemical test results were submitted for the purpose of validation. Quality assurance checks were undertaken by independent consultants and at an independent laboratory selected by Intergeo. Long term monitoring of water quality was undertaken for a period of one year after remediation work had been completed. Both the regulatory authorities and Clients representatives endorsed the quality of remediation now completed at the site. Subsequent to completion of the remediation work Redrew Homes constructed a prestige housing development. The properties at "Belvedere Place" retailed at premium prices. On the MEPC site the Post Office, amongst others, has located a major sorting office for the London area. Exceptionally high standards of remediation, control and documentation were a requirement for the work undertaken here.aken here.

• Journal of Soil and Groundwater Environment
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• v.20 no.1
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• pp.56-64
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• 2015

Acid mine drainage occurrence is a serious environmental problem by mining industry, it usually contains high levels of metal ions, such as iron, copper, zinc, aluminum, and manganese, as well as metalloids of which arsenic is generally of the greatest concern. An indigenous plant extract was used to produce calcium carbonate from Canavalia ensiformis as effective biomaterial, and its ability to form the calcium carbonate under stable conditions was compared to that of purified urease. X-ray diffraction and scanning electron microscopy were employed to elucidate the mechanism of calcium carbonate formation from the crude plant extracts. The results revealed that urease in the plant extracts catalyzed the hydrolysis of urea in liquid state cultures and decreased heavy metal amounts in the contaminated soil. The heavy metal amounts were decreased in the leachate from the treated mine soil; 31.7% of As, 65.8% of Mn, 50.6% of Zn, 51.6% of Pb, 45.1% of Cr, and 49.7% of Cu, respectively. The procedure described herein is a simple and beneficial method of calcium carbonate biomineralization without cultivation of microorganisms or further purification of crude extracts. This study suggests that crude plant extracts of Canavalia ensiformis have the potential to be used in place of purified forms of the enzyme during remediation of heavy metal contaminated soil.

• Journal of Soil and Groundwater Environment
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• v.10 no.5
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• pp.1-10
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• 2005

Policies of the United States, the United Kingdom, the Netherlands, Germany and Denmark were compared and analyzed on risk assessment of contaminated sites. These countries were chosen from a feasible preliminary analysis of 18 countries of the European Union and the U. S. All the countries selected met two major criteria : I) implementation of risk assessment to determine the soil contamination and remediation targets of contaminated sites, ii) use of soil guidance values and risk assessment as complementary measures to determine soil contamination. Suggested policy improvements to Korea regarding these issues include i) legislation of a rational risk assessment methodology of contaminated sites, and ii) enactment of collaboration of risk assessment with the soil guidance values. To establish effective risk assessment legislation, additional in-depth research on social, economic and long-term effects of the proposed risk assessment methodologies, as well as the mutual consent of all parties including academia, industry, and administration will be necessary. Linking risk assessment with soil guidance values would be applicable to a site contaminated where the contaminant concentration exceeds a certain soil guidance value. In parallel, application of risk assessment to a site where a contaminant concentration is naturally different such as mining sites would be plausible. The policy suggestions above are not yet conclusive due to a lack of policy implementation, and simulation. Thus, additional research on developing risk assessment methodology is needed. Nevertheless, initiation of the suggested policy would increase the efficacy of Korean policy regarding the survey and remediation of contaminated sites.

• Journal of Korean Society on Water Environment
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• v.23 no.5
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• pp.665-675
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• 2007

In-situ Air Sparging (IAS, AS) is a remediation technique in which organic contaminants are volatilized from saturated zone to unsaturated layer. This study focuses on the removal and interaction of Volatile Organic Compounds (VOCs) and $CO_2$, and Total Petroleum Hydrocarbon (TPH) in saturated and unsaturated, and air space zone on the unsaturated soil surface. Soil sparging temperature of hot air has risen to $34.9{\pm}2.7^{\circ}C$ from $23.0{\pm}1.9^{\circ}C$ for 36 days. At the diffusing point, fluid TPH concentrations were reduced to 78.7% of the initial concentration in saturated zone when hot air was sparged. The TPH concentrations were decreased to 66.1% for room temperature air sparging. The amount of VOCs for hot air sparging system, in air space, was approximately 26% larger than constant air sparging system. The amount of $CO_2$ was 4,555 mg (in unsaturated zone) and 4,419 mg (in air space) when hot air was sparged was 3,015 mg (in unsaturated zone) and 3,634 mg (in air space) for room air temperature in the $CO_2$ amount. The removals of VOCs and biodegradable $CO_2$ through the hot air sparging system (modified SVE) were more effective than the room temperature air sparging. The regression equation were $Y=976.4e^{-0.015{\cdot}X}$, $R^2=0.98$ (hot air sparging) and $Y=1055e^{-0.028{\cdot}X}$, $R^2=0.90$ (room temperaure air sparging). Estimated remediation time was approximately 500 days, if final saturated soil TPH concentration was set to 1.2 mg/L application of tail effect.

• Journal of Soil and Groundwater Environment
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• v.9 no.1
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• pp.54-62
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• 2004

In order to enhance the efficiency of removal a series of ElectroKinetic Remediation (EKR) tests on ferrous soil contaminated by lead are carried out using acids, chelates and surfactant as flushing agents. The test results indicate that pH in the electrolyte rapidly reached at steady state as the introduce of flushing solution of the lower pH, the type of flushing solution have no effect the distribution of electrical voltage within the sample but the increasing of solution concentration increases it at x/L=0.9. In the distribution of the residual lead in the sample SDS is the highest. Also, the removal efficiency for acetic acid concentration of 1mM Is the highest but the concentration of acetic acid significantly have no effect.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.10a
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• pp.1-11
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• 2003

The objectives of this paper are to overview present status of soil pollution in Korea, to review the current policies and management strategies for soil pollution prevention and remediation of contaminated sites, and to suggest some recommendations to be considered toward more efficient policies. Soils in Korea are contaminated mainly by industrial facilities, landfills, underground storage tanks, abandoned/inactive mines, military camps, and other sources. Concentrations of most of soil pollutants were similar to the background levels, except for a few heavily contaminated sites such as industrial sites or abandoned/inactive mines. The Soil Environment Conservation Act (SECA), which was effective from 1995, provides a comprehensive legal framework for both preventing soil pollution and remedying contaminated sites in Korea. The Act includes various management policies such as the designation of standards and soil pollution policy area, soil monitoring networks, management of suspected contamination sources, and extended 'polluter-pays' principle. To make current policies more efficient and reasonable, some policies or strategies such as the establishment of national priority list, more detailed standards, risk-based cleanup goal, fund raise, soil erosion problem, and finally, integrity between soil and groundwater management frameworks may need to be pursued in the long term.