• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.04a
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• pp.503-508
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• 2004

Optimal remediation design using the pump and treat(P&T) method and natural attenuation was accomplished in consideration for degradation processes, such as sorption and first-order decay rate. Variation of both sorption and first-order decay rate has influence on design of optimal remediation application. When sorption effect increases, the more pumping rate and pumping wells are required. The location of operated wells is on the centerline of contaminant plume and wells near hot spot are mainly operated when sorption effect increases. The higher of first-order decay rate, the less pumping rate is required. These results show that the degradation processes have to be considered as one of the essential factors for optimal remediation design.

• Proceedings of the Korean Society for Quality Management Conference
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• 2004.04a
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• pp.307-312
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• 2004

Contamination of industrial sites has happened by a variety compounds. Petroleum hydrocarbons, which are readily biodegradable, are reported principle contaminats in most industrial sites. Therefore, the use of biological processes will be a promising technology for remediation of industrial sites. This paper addresses the possible use of biological processes in remediation of contaminated industrial sites and discusses the background and main streams of the process. The paper also characterizes representative biological systems developed for application.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.04a
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• pp.371-374
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• 2005

We accomplished optimization for pump and treat (P&T) designs in consideration of degradation processes such as retardation and biodegradation, which are significant for contaminant fate in hydrogeology. For more desirable remediation, optimal pumping duration and minimum pumping rate constraint problems are studied. After a specific P&T duration, it replaces the P&T with the enhanced natural attenuation (ENA), which induces aerobic biodegradation by maintaining oxygen concentration. The design in this strategy carries out the optimization for the number and locations of oxygen injection wells.

• Economic and Environmental Geology
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• v.53 no.4
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• pp.441-477
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• 2020

There have been raised other environmental issues related to remediated soils piled up in numerous carry-out processing facilities because a considerable quantity of them have been produced every year, but most of them have not been relevantly reused or recycled. Thus, this article reports the trend of researches on the development of techniques to restore the quality of remediated soils to activate their reuse and recycling. Firstly, the tendency of change in soil properties through remediation processes was looked over, and then the degradation of soil quality was characterized according to the type of remediation processes. Besides, the direction of policy to promote the reuse and recycling of remediated soils was introduced, and finally, the future works needed were suggested. This article was prepared based on the results of the survey of domestic and foreign literature. A number of literature were reviewed to scrutinize the change of soil properties due to remediation processes and diverse techniques for the amendment and restoration of remediated soils. Furthermore, the policies related to the reuse and recycling of remediated soils were arranged with the reference of the first and second versions of the Soil Conservation Master Plan of Korea. The literature survey focused on three kinds of remediation technologies, such as land farming, soil washing, and thermal desorption, which were most frequently used so far in Korea. The results indicate that the tendency of change in soil properties was significantly different depending on the type of remediation processes applied, and the degradation characteristics of soil quality were also totally different between them. The soil amendment and restoration can be categorized as three techniques depending on the type of substances used, such as inorganic, organic, and biological ones. Diverse individual materials have been used, and the soil properties improved or enhanced were dependent on the type of specific materials utilized. However, few studies on the restoration of soil qualities degraded during the remediation processes have not been carried out so far. The second Soil Conservation Master Plan states the quality certification and target management system of remediated soils, and it is expected that their reuse and recycling will be facilitated hereafter. With the consideration of the type of remediation processes implemented and public utility, the restoration technologies of remediated soils should be developed for the vitalization of their reuse and recycling. Besides, practical and specific measures should be taken to support the policy specified in the second Soil Conservation Master Plan and to promote reuse/recycling of remediated soils.

• Journal of Soil and Groundwater Environment
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• v.18 no.3
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• pp.73-81
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• 2013

Various remediation methods have been applied to clean soils contaminated with pollutants. They remove contaminants from the soils by utilizing physicochemical, biological, and thermal processes and can satisfy soil remediation standards within a limited time; however, they also have an effect on the biological functions of soils by changing soil properties. In this study, changes of the biological properties of soils before and after treatment with three frequently used remediation methods-soil washing, land farming, and thermal desorption-were monitored to investigate the effects of remediation methods on soil biological functions. Total microbial number and soil enzyme activities, germination rate and growth of Brassica juncea, biomass change of Eisenia andrei were examined the effects on soil microorganisms, plant, and soil organisms, respectively. After soil washing, the germination rate of Brassica juncea increased but the above-ground growth and total microbial number decreased. Dehydrogenase activity, germination rate and above-ground growth increased in both land farming and thermal desorption treated soil. Although the growth of Eisenia andrei in thermal desorption treated soil was higher than any other treatment, it was still lower than that in non-contaminated soil. These results show that the remediation processes used to clean contaminated soil also affect soil biological functions. To utilize the cleaned soil for healthy and more value-added purposes, soil improvement and process development are needed.

• Journal of Preventive Medicine and Public Health
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• v.54 no.5
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• pp.376-379
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• 2021

Elemental mercury exposure can result in significant toxicity. Source decontamination and remediation are often required after larger elemental mercury exposures, but the details of these processes are infrequently reported. In the case described herein, a 64-year-old woman and her husband were exposed to elemental mercury in their home after the husband purchased it online for the purpose of recreational barometer calibration. After the mercury reportedly spilled during the calibration process, a vacuum cleaner was used to decontaminate the affected surface; this led to extensive mercury contamination of the home. The couple was relocated from the home while remediation occurred over the course of several weeks. Vacuum cleaning of an elemental mercury spill can lead to extensive volatilization and recirculation of mercury vapor. For smaller mercury spills, careful removal of visible mercury beads by using an eyedropper, cardboard, and masking tape is recommended. Larger spills require professional decontamination and remediation and may necessitate involvement of governmental resources. Vacuum cleaning should not be used as an initial method of decontamination after elemental mercury exposure. Careful attention to source decontamination can reduce the emotional and financial costs associated with extensive remediation after elemental mercury exposure.

• Journal of Korean Society on Water Environment
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• v.21 no.4
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• pp.398-402
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• 2005

The enzyme Xeronine was investigated as a microbial activating substance in biological wastewater treatment processes. Xeronine as bio-stimulant was injected in the anaerobic sludge and the activated sludge treating wastewater in order to examine the effect of hidden benefits. Bio-stimulant did not show significant improvement of anaerobic treatablity. In the aerobic system, higher bio-stimulant dose condition resulted in slightly more removal of nitrogen and phosphorus. Floc aggregation and zone settling velocity as solid-liquid separation factors in activated sludge systems was enhanced by bio-stimulant. Effects of bio-stimulants injection on improvement of water quality and microbial activity did not clear in terms of normal operation conditions.

• Journal of Soil and Groundwater Environment
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• v.17 no.4
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• pp.36-43
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• 2012

Various methods are used to remediate soil contaminated with heavy metals or petroleum. In recent years, harsh physical and chemical remediation methods are being used to increase remediation efficiency, however, such processes could affect soil properties and degrade the ecological functions of the soil. Effects of soil washing, thermal desorption, and land farming, which are the most frequently used remediation methods, on the physicochemical properties of remediated soil were investigated in this study. For soils smaller than 2 mm, the soil texture were changed from sandy clay loam to sandy loam because of the decrease in the clay content after soil washing, and from loamy sand to sandy loam because of the decrease in the sand content and increase in silt content during thermal desorption, however, the soil texture remained unchanged after land farming process. The water-holding capacity, organic matter content, and total nitrogen concentration of the tested soil decreased after soil washing. A change in soil color and an increase in the available phosphate concentration were observed after thermal desorption. Exchangeable cations, total nitrogen, and available phosphate concentration were found to decrease after land farming; these components were probably used by microorganisms during as well as after the land farming process because microbial processes remain active even after land farming. A study of these changes can provide information useful for the reuse of remediated soil. However, it is insufficient to assess only soil physicochemical properties from the viewpoint of the reuse of remediated soil. Potential risks and ecological functions of remediated soil should also be considered to realize sustainable soil use.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.10a
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• pp.681-688
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• 2002

Study was peformed to develop the‘environmental double pile’for the remediation of low-permeable contaminated soil. This technique is similar in function to‘sand drain pile’But this applies recyclable oyster shell treated as waste materials to a drain material and the pile is consisted of two layers. Inner metal pile is located in center and oyster shells are filled around it. By this technology, contaminated ground water is pumped out through the oyster shell and purified by drainage, adsorption, and reaction processes. Afterwards, the grout material is injected through the inner pile for the effect of the solidification / stabilization. As a result, the concept of this technique is a development of one-step process technology. Through the test, a consolidation characteristic by radial drain is going to be evaluated and the optimum standard of this technology will be calculated.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.04a
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• pp.163-166
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• 2002

The concurrent injection of cosolvent and air, a cosolvent-air (CA) flood was recently suggested for a dense nonaqueous phase liquid (DNAPL) remediation technology. The objectives of this study were to elucidate the DNAPL removal mechanisms of the CA flood and to quantify mass transfer rate coefficients during CA flooding. DNAPL removal mechanisms were examined by evaluating the effects of air flow rate and DNAPL solubility and visually documented at a pore-scale. Two serial processes, immiscible displacement and dissolution, were experimentally and visually documented during CA flooding. Mass transfer rate coefficients (K) were computed from the data showing PCE saturation versus time. Results showed that CA floods exhibited higher K values than cosolvent floods without concurrent air injection. (This document has not been subjected to Agency review and therefore does not necessarily reflect the views of the Agency, and no official endorsement should be inferred.)