• Environmental Engineering Research
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• 제17권3호
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• pp.145-150
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• 2012

Pb-contaminated soil at a clay shooting range was analyzed by the sequential extraction method to identify metal binding properties in terms of detrital and non-detrital forms of the soil. Most of the metals in the soils existed as non-detrital forms, exchangeable and carbonate-bound forms, which could be easily released from the soil by a washing method. Therefore, the characteristics of Pb desorption for remediation of the Pb-contaminated soil were evaluated using hydrochloric acid (HCl) by a washing method. Batch experiments were performed to identify the factors influencing extraction efficiency. The effects of the solid to liquid (S/L) ratio (1:2, 1:3, and 1:4), soil particle size, and extraction time on the removal capacity of Pb by HCl were evaluated. Soil samples were collected from two different areas: a slope area (SA) and a land area (LA) at the field. As results, the optimal conditions at 2.8 to 0.075 mm of particle size were 1:3 of the S/L ratio and 10 min of extraction time for SA, and 1:4 of the S/L ratio and 5 min of extraction time for LA. The characteristics of Pb desorption were adequately described by two-reaction kinetic models.

• 한국지하수토양환경학회지:지하수토양환경
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• 제29권1호
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• pp.63-71
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• 2024

Hydrothermal Reaction (HTR) was applied for the stabilization of contaminated soil with heavy metals, and then the test determined the optimal conditions for HTR. After HTR, the concentration of heavy metals in the contaminated soil increased. However, it was observed that the leachability potential significantly decreased as determined by TCLP and SPLP tests. This decrease was attributed to a decline in fractions 1-2 and an increase in fractions 3-4 as revealed by sequential extraction procedure. Due to the mineralogical characteristics of the dredged soil, distinct changes were not evident in the five-stage fraction. Therefore, it is deemed necessary to understand the chemical and mineralogical characteristics of the target soil for HTR application in order to selectively address contaminants. Comparison among operating conditions determined the optimal condition to be at 240℃ for one hour.

• 한국지하수토양환경학회지:지하수토양환경
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• 제18권1호
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• pp.67-77
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• 2013

To improve the energy efficiency of conventional thermal treatment, soil remediation with microwave has been studied. In this study, the remediation efficiency of contaminated soil with semi-volatile organic contaminants were evaluated with microwave oven and several additives such as water, formic acid, iron powder, sodium hydroxide (NaOH) solution, and activated carbon. For the experiment, loamy sand and sandy loam collected from Imjin river flood plain were intentionally contaminated with hexachlorobenzene and phenanthrene, respectively. The contaminated soils were treated with microwave facility and the mass removals of organic contaminants from soils were evaluated. Among additives that were added to increase the remediation efficiency, activated carbon and NaOH solution were more effective than water, iron powder, and formic acid. When 10 g of hexachlorobenzene (142.4 mg/kg-soil) or phenanthrene (2,138.8 mg/kg-soil) contaminated soil that mixed with 0.5 g iron powder, 0.5 g activated carbon and 1 ml 6.25 M NaOH solution were treated with microwave for 3 minutes, more than 95% of contaminants were removed. The degradation of hexachlorobenzene during microwave treatments with additives was confirmed by the detection of pentachlorobenzene and tetrachlorobenzene. Naphthalene and phenol were also detected as degradation products of phenanthrene during microwave treatment with additives. The results showed that adding a suitable amount of additives for microwave treatments fairly increased the efficiency of removing semi-volatile soil organic contaminants.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 총회 및 춘계학술발표회
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• pp.131-134
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• 2004

Several physical and chemical methods have been used for remediation contaminated by oils. However the cost was very high and secondary pollution rose during treating. The purpose of this study was to comprision TPH (total petroleum hydrocarbon) removal from artificially contaminated soil by diesel with and without seeding anaerobic digested sludge. After 120 days of overall at 35$^{\circ}C$, removal efficiency of TPH with seeding sludge was 2-3 times higher than blank. Also, the more amount seeding sludge, TPH removal efficiency and CH$_4$ content more obtained. It was sad that seeding of anaerobic digested sludge was a good method for enhancing TPH removal efficiency without increasing operating cost. Sulfate, nitrate-reducing, methanogenic condition were evaluated for alkane, isoprenoid as target contaminated soil.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1999년도 봄 학술발표회 논문집
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• pp.543-550
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• 1999

Hazardous substances produced from industrial sectors have caused serious contamination of soils and groundwater. The hydrophobic organic compounds in the subsurface are hard to be decomposed, and as they soil on the soil or last as a NAPL they might contaminate the groundwater for a long time. Although we recognize the danger of contaminated subsurface, very little was known about the effective remediation technique. This paper focuses on the remediation of the p-Cresol which contaminated subsurface by applying the surfactant-enhanced description technique. Sorption characteristics of soils and organic compounds are studied, and the applications of surfactant solution are studied for effective rededication. The results from this study could be used as some data for surfactant-enhanced rededication. The flexible-wall permeameter tests are performed in which in-situ remediation is simulated. Results show that triton X-100 at 2% solution disrobes p-Cresol 1.7 times as much as water description in the flexible-wall permeameter tests.

• 한국지반환경공학회 논문집
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• 제13권12호
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• pp.59-66
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• 2012

본 연구에서는 철도정비창 부지 내에 폐기물 및 중금속오염 구간에서 채취한 토양을 대상으로 하였다. 그리고 효율적인 정화공정 설계를 위하여 고농도 오염구간, 저농도 오염구간, 폐주물사 함유 시료를 대상으로 입도분포 및 입도 분포 오염농도 분석을 실시하였다. 하지만 폐콘크리트, 폐목재 등의 건설폐기물, 폐주물사, 소각재 등이 부지 전반에 걸쳐 매립되어 있어 일반토양 오염과 다른 양상을 보이고 있었다. 따라서 일반적인 중금속정화기술로는 오염원이 감소하지 않아 혼합된 폐기물 중에 자성을 띠는 성분을 자력선별을 적용하여 실험한 결과 중금속 오염도는 감소하는 것으로 나타났다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제26권6호
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• pp.36-46
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• 2021

The Soil Health Index (SHI) developed by Park et al. (2021) is used to evaluate soil health on remediated soils collected from several remediation project sites and monitored the changes of SHI during the remediation process of land farming, soil washing, and thermal desorption. In the case of land farming, the soils remediated below a legal standard didn't show any significant changes in indices of SHI except the downgrade of available phosphate from medium to a low level. The SHI scores were ranged from 52 to 56 in the contaminated soil and 54 to 57 in the remediated soil. With soil washing, bulk density changed from high to a low level, and available phosphate was lowered from medium to low level. As the SHI scores were evaluated as 58 to 63 for contaminated soil and 38 to 42 for remediated soils. For thermal desorption, soil respiration rate was reduced from high to low level and SHI was scored as 50 to 51 for contaminated soils and 43 to 47 for remediated soils. Even though any abrupt changes of the SHI in remediated soils were not identified in the soils used in this study, it is expected that soil in different conditions such as types and concentrations of contaminant and soil characteristics would result in distinguished changes of the SHI. There is a room for more studies collect diverse information on SHI across the country.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 추계 학술발표회
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• pp.268-276
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• 2008

The status of contaminated soils vary widely ; therefore, the techniques and equipment applicable to the soil concerned should be selected and used after careful consideration. Hyundai Soil Washing is physical-chemical separation based on mining and mineral processing principles for removing a broad range of organic and inorganic contaminants from soil. Mobile plant(capacity 15 tons./hr) was installed for this project. The goals of this project were 1) to verify the applicability of the washing process, which showed reliable results in the pilot plant with various kind of contaminated soils and 2) to promote recycling of the washed soil as a backfill on site. The results revealed that $F^-$ and $Pb^{2+}$ in the soil were effectively washed out to a certain level which washed soil was acceptable for recyeling.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 1998년도 공동 심포지엄 및 추계학술발표회
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• pp.189-194
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• 1998

Geochemical study was carried out to find out the distribution of metals and cyanide in soil in the vicinity of the abandoned Keum-Jung mine. Chemical analysis showed that content of As in soil around tailings exceeded 15mg/kg, Korean standard of soil contamination in the farm land. That means the contamination of soil by As is due to input of tailings. According to total decomposition of tailings, As was highly concentrated in tailings. However the water in tailings impoundment was changed to acidic and contaminated by metal and sulfate because the tailings in the top of the tailings impoundment had been oxidized. Acid mine drainage contaminated the water course in the vicinity of the paddy soils. The proper measures are required to prevent contamination of the soil and water in the vicinity of the Keum-Jung mine.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 1998년도 공동 심포지엄 및 추계학술발표회
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• pp.41-47
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• 1998

The solvent flushing apparatus for soil remediation was manufactured. After the soil around nuclear facilities was sampled and was compulsorily contaminated by Co, the remediation characteristics by solvent flushing were analyzed. Meanwhile, one-dimensional solute transport within nonequilibrium sorption code was developed for modelling of the soil remediation, input parameters for modelling were measured by laboratory experiment. Experimental results are as follows : When water was used as a solvent, the higher was the hydraulic conductivity, the higher the efficiency of soil remediation was. When EDTA solution was used as a solvent, the soil remediation efficiency of EDTA solution showed higher than that of water.