• Journal of Soil and Groundwater Environment
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• v.22 no.6
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• pp.48-56
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• 2017

Although various methods have been investigated for treatment of crude oil contaminated soil, more researches are still required to preserve soil environment. This study investigated the potential utility of subcritical water in remediation of crude oil contaminated soil under various experimental conditions including temperature ($150-300^{\circ}C$), flow rate (1.0-2.0 mL/min) and extraction time (60-120 min). The removal rate of crude oil gradually increased with increasing temperature and time. After treatment at $200^{\circ}C$ and $300^{\circ}C$ for 60 min, the remaining concentration of crude oil met the Kuwait standard clean-up level (10,000 mg/kg) and the Korean standard level (2,000 mg/kg), respectively. The removal efficiency of crude oil increased from 77.8% to 88.4% with increasing extraction time from 60 to 120 min at $250^{\circ}C$. A decreasing rate of oil removal was observed as flow rate increased, possibly due to channeling flow occurred within the soil body at higher flow rate condition. Overall, the results revealed that subcritical water extraction process could be feasible for remediation of crude oil contaminated soil, and the relative effect of parameters on the oil removal was in the order of temperature > time > flow rate.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.1069-1080
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• 2008

The mechanical characteristic of Lightweight Foamed Soil(LWFS) are investigated in this research. LWFS is composed of the in-suit soil, cement and foam to reduce the unit-weight and increase compressive strength. The unconfined compressive tests are carried out on the prepared specimens of LWFS with various soil types to investigate the relationship between compressive strength of LWFS and physical properties of soil. The result indicate that coefficient of gradation($C_g$) and liquid limit(LL) are more important factor affecting compressive strength than other physical properties of soil and coefficient of gradation($C_g$) and liquid limit(LL) can standard to determine the optical soil among the in-situ soils for LWFS.

• Journal of Environmental Science International
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• v.17 no.9
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• pp.1015-1021
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• 2008

This study was performed to examine the accumulated concentrations (conc.) of cadmium (Cd) in the organs of Arabidopsis thaliana grown in the soil with different conc. of Cd. The official standard conc. of Cd of pollutant exhaust notified by the Korean ministry of environment (0.1 mg/L) and ten times higher (1 mg/L) and fifty times higher (5 mg/L) conc. and no Cd in the soil as control were used for this investigation. The results showed that accumulated conc. of Cd in the stems of plant grown in the soil with different conc. (0.1, 1 and 5 mg/L) were increased 9%, 24% and 286% respectively, compared with normal plant stem. The accumulated conc. of Cd in the leafs of plant gown in the soil with official standard conc. and conc. ten times higher and conc. fifty times higher were increased 3%, 22% and 453%, respectively, compared with normal plant leaf. The accumulated conc. of Cd in the root of plant grown in the soil with 0.1 and 1 mg/L conc. of Cd were increased 6%, 19%, respectively, compared with normal plant root. However, it was observed about 84% of increased accumulation of the Cd in the root of plant, when highest (5 mg/L) conc. was used. The accumulated conc. of Cd in the different organs of Arabidopsis thaliana were increased according to increase of Cd conc. in the soil. When official standard conc. and ten times higher conc. of Cd were used, the accumulated conc. of Cd increased average 6%, 21%, respectively, compared with normal plant organ, and the accumulated conc. of Cd between leaf, stem and root were not significant. However, the accumulated conc. of Cd in the plant organs gown in the conc. fifty times higher were increased about 285%, compared with normal plant. In addition, the accumulated conc. of Cd in different organs of Arabidopsis thaliana exhibited wide differences between organs, that is, stem was increased 118% than root, leaf was increased 256%, 64% than root and stem, respectively. These results show that accumulated conc. of Cd in Arabidopsis thaliana with highest (5 mg/L) conc. of Cd in soil, were much higher in the leaf than the stem or root in proportion to the conc. of Cd contaminated within the soil.

• Journal of Soil and Groundwater Environment
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• v.16 no.1
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• pp.71-81
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• 2011

Cause of contamination in the study area nearby Jang Hang Refinery is dust scattering in refinery stack, and soil washing treatment is one of the proper technologies for soil remediation in this area. Site conditions frequently limit the selection of a treatment process. A treatment technology may be eliminated based on the soil classification or physicochemical characteristics of soil. This study was assessed the soil washing efficiency by conducting of soil characteristic analysis in the vicinity of Jang Hang Refinery Stack within a 2 km radius. Also, it was decided about remedial range with comparative analysis of As in soil by Korean Standard Test Method before/after revision, whereupon As concentration in soil showed a increasing tendency after revision. As a result, the soil washing using the size separation of soil was determined through identifying of As species in the soil. In this site, only particle size distribution and water content of soil can provide the initial means of screening for the potential use of soil washing.

• Journal of the Korean Society of Clothing and Textiles
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• v.45 no.5
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• pp.840-851
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• 2021

In this study, we used a chemiluminescence reaction to investigate the removal effect of pet soil, such as dog blood, urine and feces. The soiled fabrics were washed with a standard laundry course of 30℃ and a washing time of 30 min and a pet care laundry course of 40-60℃ and a washing time of 100 min. The detergency was evaluated by the surface reflectance and chemiluminescence reaction (bloodstain detection by luminol test and urine-stain and feces-stain detection by UV blacklight test) before and after washing. The surface reflectance results did not show any difference in detergency for both courses, whereas the chemiluminescence reaction did. The detergency of the pet care course compared to the standard course was 101% according to the surface reflectance and 120% according to the chemiluminescence reaction. Therefore, residual stains not detected by surface reflectance can be evaluated through chemiluminescence reaction, and it was confirmed that pet stains can be managed more hygienically by washing for a long time at a high temperature.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.23 no.6
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• pp.57-73
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• 2020

A study was conducted to present the criteria for evaluating the revegetation method of the slope of the expressway. The results of comparative analysis between 2019-2020 field survey and existing research data (2015-2016) are as follows. Soil is a very important factor at the beginning of revegetation work. However, after the plant has settled, the importance of the soil composition diminishes. Among the plants used, the number of plants sown at the beginning gradually decreases. And it changes as it competes with invading plants. Among the plants used for sowing, it was found to affect the vegetation composition in the order of exotic grass > native herb and wildflower > native tree. Plant coverage is continuously evaluated as an important factor regardless of the time. The vegetation structure on the slope will change continuously over time. New items need to be evaluated in situations where a lot of time has elapsed since the application of revegetation work. It is desirable to use the current evaluation standard only to perform the evaluation within 1 to 2 years. In the long run, it is necessary to establish a new evaluation standard that adjusts the weights of each item.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.5
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• pp.399-407
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• 2009

Laser induced breakdown spectroscopy(LIBS) is an simple analysis method for directly quantifying many kinds of soil micro-elements on site using a small size of laser without pre-treatment at any property of materials(solid, liquid and gas). The purpose of this study were to find an optimum condition of the LIBS measurement including wavelengths for quantifying soil elements, to relate spectral properties to the concentration of soil elements using LIBS as a simultaneous un-breakdown quantitative analysis technology, which can be applied for the safety assessment of agricultural products and precision agriculture, and to compare the results with a standardized chemical analysis method. Soil samples classified as fine-silty, mixed, thermic Typic Hapludalf(Memphis series) from grassland and uplands in Tennessee, USA were collected, crushed, and prepared for further analysis or LIBS measurement. The samples were measured using LIBS ranged from 200 to 600 nm(0.03 nm interval) with a Nd:YAG laser at 532 nm, with a beam energy of 25 mJ per pulse, a pulse width of 5 ns, and a repetition rate of 10 Hz. The optimum wavelength(${\lambda}nm$) of LIBS for estimating soil and plant elements were 308.2 nm for Al, 428.3 nm for Ca, 247.8 nm for T-C, 438.3 nm for Fe, 766.5 nm for K, 85.2 nm for Mg, 330.2 nm for Na, 213.6 nm for P, 180.7 nm for S, 288.2 nm for Si, and 351.9 nm for Ti, respectively. Coefficients of determination($r^2$) of calibration curve using standard reference soil samples for each element from LIBS measurement were ranged from 0.863 to 0.977. In comparison with ICP-AES(Inductively coupled plasma atomic emission spectroscopy) measurement, measurement error in terms of relative standard error were calculated. Silicon dioxide(SiO2) concentration estimated from two methods showed good agreement with -3.5% of relative standard error. The relative standard errors for the other elements were high. It implies that the prediction accuracy is low which might be caused by matrix effect such as particle size and constituent of soils. It is necessary to enhance the measurement and prediction accuracy of LIBS by improving pretreatment process, standard reference soil samples, and measurement method for a reliable quantification method.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1757-1763
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• 2011

In recent years, accordance to industrial development project on railway investment, adverse environmental issues of the investment, such as disputed cases about recycling and usage of Ballast Cleaner excavated soil, have been continuously increasing. It will not only enhance the regulation of soil contamination but take considerable time and cost in future. In this study, we investigated soil contamination and burnability with soil of Chungang Line, Taebaek Line, Chungbuk Line, in order to seize a possibility of recycling Ballast Cleaner excavated soil for the natural materials and substantial heat sources, which are necessary resources for cement manufacturing process. As a result of this study, It is found that Ballast Cleaner excavated soil is satisfied with a standard. The excavated soil contains a lot of cement ingredients and fossil fuel dust incurred from freight transportation, so it is expected to use for ingredients of cement and replacement of heat sources.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1998.11a
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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.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.09a
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• pp.191-194
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• 2002

Humic acid, fulvic acid and humin present in volcanic ash soil were isolated by IHSS standard procedure and their characteristics were analyzed as a basic study to evaluate the effect of humic substances on the behaviour of pollutants in contaminated surface soil. The volcanic ash soil contained 42.1 % of total organic matter based on the oven-dried soil, and humin, humic and fulvic acids corresponded to 67.5 %, 15.2 %, 7.6 % of TOM respectively. Structural informations of the humic fractions were obtained from their elemental analysis and IR, CPMAS C-13 NMR spectral analysis and the differences among them are discussed with their C/H, O/C ratios and distributions of carbon types in the molecules.