• Journal of Soil and Groundwater Environment
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• v.11 no.6
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• pp.8-17
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• 2006

Laboratory scale experiments were performed to investigate the removal efficiency of the in-situ chemical oxidation method and the air-sparging method for diesel contaminated soil and groundwater. Two kinds of diesel contaminated soils (TPH concentration : 2,401 mg/kg and 9,551 mg/kg) and groundwater sampled at Busan railroad station were used for the experiments. For batch experiments of chemical oxidation by using 50% hydrogen peroxide solution, TPH concentration of soil decreased to 18% and 15% of initial TPH concentration. For continuous column experiments, more than 70% of initial TPH in soil was removed by using soil flushing with 20% hydrogen peroxide solution, suggesting that most of diesel in soil reacted with hydrogen peroxide and degraded into $CO_2$ or $H_2O$ gases. Batch experiment for the air-sparging method with artificially contaminated groundwater (TPH concentration : 810 mg/L) was performed to evaluate the removal efficiency of the air-sparging method and TPH concentration of groundwater decreased to lower than 5 mg/L (waste water discharge tolerance limit) within 72 hours of air-sparging. For box experiment with diesel contaminated real soil and groundwater, the removal efficiency of air-sparging was very low because of the residual diesel phase existed in soil medium, suggesting that the air-sparging method should be applied to remediate groundwater after the free phase of diesel in soil medium was removed. For the last time, the in-situ box experiment for a unit process mixed the chemical oxidation process with the air-sparging process was performed to remove diesel from soil and groundwater at a time. Soil flushing with 20% hydrogen peroxide solution was applied to diesel contaminated soils in box, and subsequently contaminated groundwater was purified by the air-sparging method. With 23 L of 20% hydrogen peroxide solution and 2,160 L of air-sparging, TPH concentration of soil decreased from 9,551 mg/kg to 390 mg/kg and TPH concentration of groundwater reduced to lower than 5 mg/L. Results suggested that the combination process of the in-situ hydrogen peroxide flushing and the air-sparging has a great possibility to simultaneously remediate fuel contaminated soil and groundwater.

• Journal of Soil and Groundwater Environment
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• v.10 no.4
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• pp.45-53
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• 2005

The objective of this study is to evaluate the effects of changes in soil temperature on biodegradation rate of diesel compounds from a field pilot test using hot air injection process. Total remediation time was estimated from in-situ biodegradation rate and temperature for optimum biodegradation. All tests were conducted by measuring in-situ respiration rates every about 10 days on highly contaminated area where an accidental diesel release occurred. The applied remediation methods were hot air injection/extraction process to volatilize and extract diesel compounds followed by a bioremediation process to degrade residual diesels in soils. Oxygen consumption rate varied from 2.2 to 46.3%/day in the range of 26 to $60^{\circ}C$, and maximum $O_2$ consumption rate was observed at $32.0^{\circ}C$. Zero-order biodegradation rate estimated on the basis of oxygen consumption rates varied from 6.5 to 21.3 mg/kg-day, and the maximum biodegradation rate was observed at $32^{\circ}C$ as well. In other temperature range, the values were in the decreasing trend. The first-order kinetic constants (k) estimated from in-situ respiration rates measured periodically were 0.0027, 0.0013, and $0.0006d^{-1}$ at 32.8, 41.1, and $52.7^{\circ}C$, respectively. The estimated remediation time was from 2 to 9 years, provided that final TPH concentration in soils was set to 870 mg/kg.

• Economic and Environmental Geology
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• v.43 no.2
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• pp.123-136
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• 2010

In order to remediate heavy metal contaminated Nong island, Maehyang-ri shooting range soils through the batch reactor scale washing were evaluated. The experiment texture soil of N3 in the Nong island at north side incline was (g)mS containing 12.9% gravel, 47.0% sand, 35.1% silt and 5.0% clay. And the N3 soil area was contaminated with Cd($22.5\pm1.9$ ppm), Cu($35.5\pm4.0$ ppm), Pb($1,279.0\pm5.1$ ppm) and Zn($403.4\pm9.8$ ppm). The EDTA(ethylene diamine tetra acetic acid, $C_{10}H_{16}N_2O_8$) in the N3 soil was observed as most effective extractants among the 5 extractants(citric acid, EDTA, phosphoric acid, potassium phosphate and oxalic acid) tested. And chemical partitioning of heavy metals after washing N3 soil with EDTA was evaluated. Removal efficiency of residual fractions was higher than that of non-residual fractions. To choose EDTA extractant which is the most effective in soil washing technology using batch reactor process cleaning Pb and Zn contaminated sits; Pb and Zn removal rates were investigated 92.4%, 94.0% removal(1,000 mM, soil:solution=5, $20^{\circ}C$, 24 hour shaking, pH=2, 200 RPM), respectively. The results of the batch test showed that the removal efficiency curve was logarithmic in soil was removal. Thus, EDTA washing process can be applied to remediate the Pb and Zn contaminated soil used in this study.

• Journal of Environmental Impact Assessment
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• v.29 no.3
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• pp.157-181
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• 2020

Sediments from rivers, lakes and marine ports serve as end points for pollutants discharged into the water, and at the same time serve as sources of pollutants that are continuously released into the water. Until now, the contaminated sediments have been landfilled or dumped at sea. Landfilling, however, was expensive and dumping at sea was completely banned due to the London Convention. Therefore, this study applied contaminated sedimentation soil of 'Royal Palace Livestock Complex' as soil purification method. Soil remediation methods were applied to pretreatment, composting, soil washing, electrokinetics, and thermal desorption by selecting overseas application cases and domestically applicable application technologies. As a result of surveying the site for pollutant characteristics, Disolved Oxigen (DO), Suspended Solid (SS), Chemical Oxygen Demand (COD), Total Nitrogen (TN), and Total Phosphorus (TP) exceeded the discharged water quality standard, and especially SS, COD, TN, and TP exceeded the standard several tens to several hundred times. Soil showed high concentrations of copper and zinc, which promote the growth of pig feed, and cadmium exceeded 1 standard of Soil Environment Conservation Act. In the pretreatment technology, hydrocyclone was used for particle size separation, and the fine soil was separated by more than 80%. Composting was performed on organic and Total Petroleum Hydrocarbon (TPH) contaminated soils. TPH was treated within the standard of concern, and E. coli was analyzed to be high in organic matter, and the fertilizer specification was satisfied by applying the optimum composting conditions at 70℃, but the organic matter content was lower than the fertilizer specification. As a result of continuous washing test, Cd has 5 levels of residual material in fine soil. Cu and Zn were mostly composed of ion exchange properties (stage 1), carbonates (stage 2), and iron / manganese oxides (stage 3), which facilitate easy separation of contamination. As a result of applying acid dissolution and multi-stage washing step by step, hydrochloric acid, 1.0M, 1: 3, 200rpm, 60min was analyzed as the optimal washing factor. Most of the contaminated sediments were found to satisfy the Soil Environmental Conservation Act's standards. Therefore, as a result of the applicability test of this study, soil with high heavy metal contamination was used as aggregate by applying soil cleaning after pre-treatment. It was possible to verify that it was efficient to use organic and oil-contaminated soil as compost Maturity after exterminating contaminants and E. coli by applying composting.

• Journal of the Mineralogical Society of Korea
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• v.23 no.4
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• pp.281-295
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• 2010

This paper deals with magnetic susceptibility, mineralogy, soil properties (pH, EC, CEC, loss on ignition), iron and manganese oxides, the content and partitioning of heavy metals (As, Cd, Cr, Cu, Ni, Pb, Zn), and their mutual relationship in the soil samples of an unpolluted, abandoned mine area, and industrial complex area. The various minerals derived from weathered bedrock were identified by X-ray diffraction in the unpolluted soil samples, except for the magnetic minerals. XRD analysis also revealed the existence of hematite and magnetite related to mine tailings and waste rocks in the abandoned mine area samples. The industrial complex area samples had carbonate minerals, such as calcite and dolomite, that might be due to anthropogenic deposition. The sum of the reducible, oxidizable, and residual fractions was over 80% for the abandoned mine area samples and over 50% for the industrial complex area samples using the sequential extraction method. The industrial complex area samples had a relatively high carbonate fraction that was associated with carbonate minerals. The content of aqua regia-extractable Fe, Mn, As, and Zn had a high positive correlation with the content of the dithionite-citrate-bicarbonate (DCB)-extractable method related to Fe/Mn oxide phases. The 54% and 58% of aqua regia-extractable Fe and As content, respectively, acted together with the concentrations of the DCB-extractable phases. Magnetic susceptibility values of total samples ranged from 0.005 to $2.131{\times}10^{-6}m^3kg^{-1}$. The samples including iron oxide minerals, such as hematite and magnetite, had a high magnetic susceptibility. The magnetic susceptibility showed a significant correlation with the heavy metals, Cd (r=0.544, p<0.05), Cr (r=0.714, p<0.01), Ni (r=0.645, p<0.05), Pb (r=0.703, p<0.01), and Zn (r=0.496, p<0.01), as well as Fe (r=0.608, p<0.01) and Mn (r=0.615, p<0.01). The aqua regia-extractable Fe and Mn content had a significant positive correlation with Cd, Cr, Cu, Ni, and Zn. However, the DCB-extractable Fe and Mn content had a significant positive correlation with As and Ni, indicating that the heavy metals were associated with Fe and Mn oxide minerals.

• Korean Journal of Soil Science and Fertilizer
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• v.34 no.1
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• pp.33-41
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• 2001

Enormous volumes of mining wastes from the abandoned and closed mines are disposed without a proper treatment in the upper Okdong River basin at Southeastern part of Kangwon Province. Erosion of these wastes contaminates soil, surface water, and sediments with heavy metals. Objectives of this research were to fractionate heavy metals in the mine tailing stored in the Sangdong Tungsten tailing dams and to assess the potential pollution index of each metal fraction. Tailing samples were collected from tailing dams at different depth and analyzed for physical and chemical properties. pH of tailings ranged from 7.3 to 7.9. Contents of total N and organic matter were in the ranges of 3.2~5.5%, and 1.3~9.1%, respectively. Heavy metals in the tailings were higher in the newly constructed tailing dam than those in the old dam. Total concentrations of metals in the tailings were in the orders of Zn > Cu > Pb > Ni > Cd, exceeded the corrective action level of the Soil Environment Conservation Law and higher than the natural abundance levels reported from uncontaminated soils. Relative distribution of heavy metal fractions was residual > organic > reducible > carbonate > adsorbed, reversing the degree of metal bioavailability. Mobile fractions of metals were relatively small compared to the total concentrations. Distribution of metals in the tailing dam profiles was metal specific. Concentrations of Cu at the surface of tailing dams were higher than those at the bottom. Pollution index (PI) values of each fraction of metals were ranged from 4.27 to 8.51 based on total concentrations. PI values of mobile fractions were lower than those of immobile fractions. Results on metal fractions and PI values of the tailing samples indicate that tailing samples were contaminated with heavy metals and had potential to cause a detrimental effects on soil and water environment in the lower part of the stream. A prompt countermeasure to prevent surface of tailings in the dams from water and wind erosions is urgently needed.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.3
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• pp.278-286
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• 2010

Veterinary antibiotics have been used to treat disease and to promote growth of livestock. However, the total amount of veterinary antibiotics in Korea was much greater than other developed countries, and there is a high potential to release residual of antibiotics to environment. Consequentially, released antibiotics into the environment produces antibiotic resistant bacteria and causes adverse effects on human health. The objective of this research was to monitor antibiotic concentration in the environment adjacent to facilities which compose chicken manure. Total of 10 antibiotics were selected based on the total amount of higher usage in Korea, and its residuals were measured from surface water, soil and sediment. The frequencies of detected antibiotics were ranged 31-92% from soil, 0-93% from water, and 33-93% from sediment. Generally, a higher frequency was observed in soil or sediment than water. Different ranges in concentration among 4 different antibiotic groups was found from not detected(N.D.) to 35.6 ${\mu}g/kg$ for soil, N.D. to 19.2 ${\mu}g/L$ for water and N.D. to 114.3 ${\mu}g/kg$ for sediment. Our findings suggest that solid phase such as soil and sediment is a critical component to be needed to conduct the environmental impact assessment of antibiotics.

• Korean Journal of Organic Agriculture
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• v.9 no.2
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• pp.101-115
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• 2001

Nitrogen applied as fertilizer for crop production is partly absorbed by plant , and the remaining nitrogen in soil might be leached out through complicated processes to the subsoil layer Especially, NO$_3$-N in leachate causes environmental pollution. The purpose of this study was focused on understanding of uptake of nutrients by plants, the behaviors of nutrients in soil and the possibility of leaching loss when nitrogen fertilizer and completely decomposed compost were applied. Lysimeters(Volume 0.15㎥, Diameter 62cm, Height 62.8cm) were installed for collecting leachate in the Jeju volcanic ash soils. Lysimeter study consisted of thirteen treatments : fallow, fallow with weeding, cropping without fertilizer and compost, three N fertilizer soil surface applications(16, 32, 64kg/10a), three N fertilizer and compost soil surface applications(16+800, 32+1600, 64+32kg/10a), two water dissolved N fertilizer applications(16, 32kg/10a), and low and high plant densities. N fertilizer was applied as urea. The growth of com(preceding crop) and potatoes(succeeding crop) and leaching loss were determined during the experimental period. The results obtained were summarized as follows ; With Increased N, pH of leachate tended to decrease and NO$_3$-N concentration of leachate increased. NO$_3$-N leaching loss was remarkably greater in soil from the bare plot without fertilization and the weed control than from plots with medium N rate and was least in the cropping plot without fertilization. NO$_3$-N concentration in leachates from the water dissolved N fertilizer application plots was 64% of that from the soil surface application plots. The concentration of Ca and K ions and the leaching loss of these ions were least from the cropping plot without fertilization and were greatest from bare plots(T1 and T2) without fertilization. The proportion of leaching and residual N in soil increased as N rate increased indicting that higher N rates increase the possibility of N leaching to subsoil layer The proportion of N leaching losses was lower at the low N rate and the high plant density. In future, fertilization prescription which can maximize fertilizer use efficiency and minimize the pollution of ground water will be needed for conserving the environments.

• Korean Journal of Environmental Agriculture
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• v.24 no.3
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• pp.222-231
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• 2005

Most of the tailings have been left without any management in abandoned metalliferous mines and have become the main source of heavy metal contamination of agricultural soils and crops in the these areas. To compare of environmental assessment of heavy metals in tailings derived from various 25-metalliferous mines in Korea, 3 different analysis methods such as water soluble, 0.1 M-HCl extractable, and total acid digestion method (aqua regia) were used. The chemical composition of water soluble in mine tailing were in the order ${SO_4}^{2-}>Ca^{2+}>Mn^{2+},\;Na^+,\;Al^{3+}>Mg^{2+},\;Fe^{3+}>Cl^-$. Specially, pH, EC, ${SO_4}^{2-},\;and\;Ca^{2+}$ concentrations in tailing varied considerably among the different mines. The average total concentrations of Cd, Cu, Pb, Zn, and As in tailing were 31.8, 708, 4,961, 2,275 and 3,235 mg/kg, respectively. Specially, the contents of Cd, Zn and As were higher than those of countermeasure values for soil contamination (Cd : 4, Zn : 700 and As : 15 mg/kg in soil) by Soil Environmental Conservation Act in Korea. The rates of water soluble heavy metals to total contents in tailings were in the order Cd > Zn > Cu > Pb > As. The rates of 0.1M-HCl extractable Cd, Cu, Pb, Zn, and As (1M-HCl) to total content were 17.4, 10.2, 6.5, 6.8 and 11.4% respectively. The enrichment factor of heavy metals in tailings were in the order As > Pb > Cd > Cu > Zn. The pollution index in tailing Au-Ag mine tailing were higher than those of other mine tailing. As a results of enrichment factor and pollution index for heavy metal contaminations in mine tailing of metalliferous mines, the main contaminants are mine waste materials including tailings.

• Economic and Environmental Geology
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• v.35 no.3
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• pp.221-227
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• 2002

Column experiments were performed to evaluate the removal efficiency of soil vapor extraction (SVE) iota TCE (trichloroethylene) and toluene in soil. Homogeneous Ottawa sands and real soils collected from contaminated area were used to investigate the effect of soil properties and SVE operation conditions on the removal efficiency. In column teats with two different sizes of Ottawa sand, the maximum effluent TCE concentration in a coarse sand column was 442 mg/L and 337 mg/L in a fine sand column. However, after 20 liter gas flushing, the effluent concentrations were very similar and more than 90% of initial TCE mass were removed from the column. For two real contaminated soil columns, the maximum effluent concentration decreased 50% compared with that in the homogeneous Ottawa coarse sand column, but 99% of initial TCE mass were extracted from the column within 40 liter air flushing, suggesting that SVE is very available to remove volatile NAPLs in the contaminated soil. To investigate the effect of contaminant existing time on the removal efficiency, an Ottawa sand column was left stable for one week after TCE was injected and the gas extraction was applied into the column. Its effluent concentration trend was very similar to those for other Ottawa sand columns except that the residual TCE after the air flushing showed relatively high. Column tests with different water contents were performed and results showed high removal efficiency even in a high water content sand column. Toluene as one of BTEX compounds was used in an Ottawa sand column and a real soil column. Removal trends were similar to those in TCE contaminated columns and more than 98% of initial toluene mass were removed with SVE in both column.