• 한국환경보건학회지
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• 제28권2호
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• pp.99-108
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• 2002

This study was carried out to evaluate the Physicochemical characteristics of mined waste(separated waste and soil) and to predict environmental effect of an old landfill site located at north of Seoul. Municipal solid waster(MSW) had been disposed of at the old landfill site used in this study for about 2 years(1990-1992). The old landfill site selected for this study had accepted mainly municipal solid waste. The landfill-mined waste contained separated waste (40.9%) and soil(59.1%) by wet weight basis. The separated waste consisted of combustible(91.0%) and non-combustible(9.0%). The combustible waste was mainly non-biodegradable plastics. The low heating value of the separated combustible waste, which is calculated by Dulong's equation, was as high as 3,470kcal/kg. According to the Korean Extraction Procedure, separated waste and soil were proved to be not hazardous. The total content of heavy metal in the separated waste and soil met standard of California State, USA. Therefore the separated waste may be relandfilled at a sanitary landfill site and/or burned up at an incinerator, and the separated old soil may be used ad landfill cover-soil at a sanitary landfill site. Water quality of two streams was grade IV, of which water could be used as industrial and agricultural water. The streams near the landfill site might not be contaminated by leachate from the old landfill site. It was estimated that organic matter in the old landfill site would not be actively biodegraded within a short period of time.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1997년도 가을 학술발표회 논문집
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• pp.383-390
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• 1997

• 한국환경복원기술학회지
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• 제5권3호
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• pp.1-8
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• 2002

Clayey paddy soils should be mixed with other good coarse soils to be used as a material for the lining, or, embankment. However, it has been difficult to separate soil particles from each other because of the internal cohesion in the soil gradation(separation) characteristics of the fine soil were investigated by various laboratory tests including the slaking durability test. Degradation rate of the soil were dependent upon the clay content and the initial water content before the submergence. The amount of degradations decreased as initial water content increased with exponential functions. The dried specimens separated into the particles after 24 hours of the submergence and specimens which water contents were less than 10% also separated into the particles after 2, or 3 days of the submergence. Compaction curves and the unconfined strength were not varied before and after the submergence. However, unconfined strength decreased as water content increased.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2002년도 Proceedings of International Symposium on Remote Sensing
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• pp.739-744
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• 2002

Recently we have discovered that sediments should be separated from lithosphere, and soil should be separated from biosphere, both sediment and soil will be mixed sediments-soil-sphere (Seso-sphere), which is using particulate mechanics to be solved. Erosion and sediment both are moving by particulate matter with water or wind. But ancient sediments will be erosion same to soil. Nowadays, real soil has already reduced much more. Many places have only remained sediments that have ploughed artificial farming layer. Thus it means sediments-soil-sphere. This paper discusses sediments-soil-sphere erosion modeling. In fact sediments-soil-sphere erosion is including water erosion, wind erosion, melt-water erosion, gravitational water erosion, and mixed erosion. We have established geographical remote sensing information modeling (RSIM) for different erosion that was using remote sensing digital images with geographical ground truth water stations and meteorological observatories data by remote sensing digital images processing and geographical information system (GIS). All of those RSIM will be a geographical multidimensional gray non-linear equation using mathematics equation (non-dimension analysis) and mathematics statistics. The mixed erosion equation is more complex that is a geographical polynomial gray non-linear equation that must use time-space fuzzy condition equations to be solved. RSIM is digital image modeling that has separated physical factors and geographical parameters. There are a lot of geographical analogous criterions that are non-dimensional factor groups. The geographical RSIM could be automatic to change them analogous criterions to be fixed difference scale maps. For example, if smaller scale maps (1:1000 000) that then will be one or two analogous criterions and if larger scale map (1:10 000) that then will be four or five analogous criterions. And the geographical parameters that are including coefficient and indexes will change too with images. The geographical RSIM has higher precision more than mathematics modeling even mathematical equation or mathematical statistics modeling.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 추계학술발표회
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• pp.136-139
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• 2003

The combined effect of bioaugmentation of dechlorinating bacterial cultures and addition of iron powder (Fe$^{0}$ ) on reductive dechlorination of tetrachloroethylene (PCE) and other chlorinated ethylenes in a artificially contaminated soil slurry (60$\mu$mo1es PCE/kg soil) were tested. Two different anaerobic bacterial cultures, a pure bacterial culture of Desulfitobacterium sp. strain Y-51 capable of dechlorinating PCE to cis-1, 2-dechloroethylene (cis-DCE) and the other enrichment culture PE-1 capable of dechlorinating PCE completely to ethylene, were used for the bioaugmentation test. Both treatments introduced with the strain Y-51 and PE-1 culture (3mg dry cell weight/kg soil) showed conversion of PCE to cis-DCE within 40 days. The treatments added with Fe$^{0}$ (0.1 -1.0 %(w/w)) alone to the soil slurry resulted in extended PCE dechlorination to ethylene and ethane and the, dechlorination rate depended on the amount of Fe$^{0}$ added. The combined use of the bacterial cultures with Fe$^{0}$ (0.1-1.0%) showed the higher PCE dechlorination rate than the separated application and the pattern of PCE dechlorination and end-product formation was different from those of the separated application. These results suggested that the combined application of Fe$^{0}$ and the bactrial culture, specially the complete dechlorinating enrichment culture such as PE-1 culture, would be practically effective for remediation of PCE contaminated soil.

• 한국지하수토양환경학회지:지하수토양환경
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• 제20권5호
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• pp.41-46
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• 2015

Three types of experiments, based on the physical properties of oily sludge landfilled soil, were conducted to recover total petroleum hydrocarbons (TPH) from the soil. These experiments included gravity separation, solvent extraction using water, and air floatation. The oil portion was not easily separated from the wet (raw) soil because water molecules aggregate the soil particles, despite the fact that the soil was sandy. However, the drying and grinding processes destroyed the aggregates, causing the TPH recovery to increase to approximately 60% when air floatation was used. The drying process decreased the specific gravity of the soil sample, thereby enhancing the overall recovery of TPH from the soil. Although thermal desorption and/or incineration are common choices for heavily dumped sites, physical separation can recover the oil portion instead of simply removing it.

• 한국초전도ㆍ저온공학회논문지
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• 제18권1호
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• pp.10-13
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• 2016

In this study, we developed a new volume reduction technique for cesium contaminated soil by magnetic separation. Cs in soil is mainly adsorbed on clay which is the smallest particle constituent in the soil, especially on paramagnetic 2:1 type clay minerals which strongly adsorb and fix Cs. Thus selective separation of 2:1 type clay with a superconducting magnet could enable to reduce the volume of Cs contaminated soil. The 2:1 type clay particles exist in various particle sizes in the soil, which leads that magnetic force and Cs adsorption quantity depend on their particle size. Accordingly, we examined magnetic separation conditions for efficient separation of 2:1 type clay considering their particle size distribution. First, the separation rate of 2:1 type clay for each particle size was calculated by particle trajectory simulation, because magnetic separation rate largely depends on the objective size. According to the calculation, 73 and 89 % of 2:1 type clay could be separated at 2 and 7 T, respectively. Moreover we calculated dose reduction rate on the basis of the result of particle trajectory simulation. It was indicated that 17 and 51 % of dose reduction would be possible at 2 and 7 T, respectively. The difference of dose reduction rate at 2 T and 7 T was found to be separated a fine particle. It was shown that magnetic separation considering particle size distribution would contribute to the volume reduction of contaminated soil.

• 한국환경농학회지
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• 제34권4호
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• pp.355-358
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• 2015

BACKGROUND: Changes in Korea's agricultural soil properties were analyzed at a four-year interval from 1999 to 2002 on a national scale and used as basis for the determination of the appropriate agricultural policy on maintaining food safety and soil quality. The scope of this study ideally requires sampling thousands of paddy, greenhouse, upland and orchard land across the country, however, due to limitations in economic and manpower resources, it was deemed necessary to reduce sampling site to greenhouse soil. In this study, we try to investigate the applicability of cultivated crops as criteria for selecting representing fields in greenhouse soils.METHODS AND RESULTS: Soil samples were collected from red pepper, oriental melon, watermelon and strawberry cultivated soil. Principal components analysis (PCA) was performed on soil chemical properties of the selected fields: pH, electron conductivity (EC), available phosphate (Av-P₂O₅), organic matter (OM), and exchangeable cation (Ex.-K, Ca, and Mg). Soil chemical properties of oriental melon cultivated soil was separated from red pepper, watermelon, and strawberry cultivated soil on PC1 and red pepper cultivated soil was separated from watermelon cultivated soil on PC2. Position on PC1 was strongly correlated with pH, Ex.-Ca and Ex.-Mg and position on PC2 was strongly correlated with OM and Av-P₂O₅.CONCLUSION: The soil chemical properties of greenhouse soil was assorted amongst the different crops. Therefore, the cultivated crops as a criteria for the selection of representative field in greenhouse soil would be used in the future.

• 한국토양비료학회지
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• 제44권1호
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• pp.118-126
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• 2011

Ester-linked fatty acid methyl ester (EL-FAME) profiles were used to describe differences in soil microbial communities influenced by conventional farming system (CFS), and organic farming system (OFS) in controlled horticultural land. Soil physicochemical properties and soil microbial communities were determined in the experimental fields. Higher organic matter content in OFS reduced soil bulk density which in turn increased the soil porosity. Generally, soil chemical properties in OFS were higher than those of CFS, but EC value in OFS was significantly lower than that of CFS. With the exception of Fe content, other macronutrient contents and pH in both farming system decreased with the soil depth. Soil microbial biomass of OFS was approximately 1.3 times in topsoil and 1.8 times in subsoil higher than those of CFS. Lower ratios of cy17:0 to $16:1{\omega}7c$ and cy19:0 to $18:1{\omega}7c$ were found in the CFS soils than the OFS soils, indicating that microbial stress decreased. The ratio of MUFA to SFA was higher in OFS due to organic input to the soil. In principal components analysis (PCA), the first variable accounted for 54.3%, while the second for 27.3%, respectively. The PC1 of the PCA separated the samples from CFS and OFS, while the PC2 of the PCA separated the samples from topsoil and subsoil. EL-FAMEs with the positive eigenvector coefficients for PC1 were cy17: 0 to $16:1{\omega}7c$ ratio, cy19:0 to $18:1{\omega}7c$ ratio, soil pH, soil organic matter, and soil $NO_3$-N content. Our findings suggest that the shifting cy19:0 to $18:1{\omega}7c$ ratio should be considered as potential factors responsible for the clear microbial community differentiation observed between different cultivation systems and soil depth in controlled horticultural land.

• Geomechanics and Engineering
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• 제38권6호
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• pp.603-609
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• 2024

In downtown subway project most of excavated soil is discarded externally, whereas in road construction excavated soil is used as filling material and management of surplus soil becomes important factor for success of the project. Excavated materials from slurry shield TBM are discharged through discharge pipe to slurry treatment plant and excavated soil mixed with bentonite are separated in separation plant by grain size. Fine material has been discarded together in filter cake without recycling. Its volume can vary according to geologic condition but statistically fine material as filter cake is about 5%~30% out of overall excavated volume. However, filter cake is non-toxic and can be recycled when mixed in the appropriate proportions with coarse aggregate. Therefore, in this study, utilization of excavated soil from a slurry shield TBM were examined and lab tests were conducted to find the proper way for mixing filter cake and aggregate to be recycled as fill material for road construction.