• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.209-209
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• 2017

The application of liquid swine manure to soil has been commonly reported to increase crop productivity by improving plant nutrient availability. This study was conducted to investigate the effect of liquid swine manure (LSM) application on yield of green manure crops in paddy. Three different application rates of LSM equivalent to 25%, 50%, and 75% of standard fertilization rate of P were applied to the paddy field after rice harvest, and two cover crops, hairy vetch (Vicia villosa Roth) and barley (Hordeum vulgare L.), were subsequently mix-seeded and cultivated. Plant height of barley was 7% higher in LSM P25% and LSM P50% compared to control treatment (no LSM application), while no significant difference was observed between LSM P75% and control. However, there were no significant differences in plant height of hairy vetch among treatments. Dry matter (DM) yield of green manure increased with LSM application rate, reaching a maximum at LSM P50% (38 and 17% yield increase over control for hairy vetch and barley, respectively), but it decreased at LSM P75% rate. Nitrogen production by green manure crops was the highest in LSM P50% treatment, where the amount of produced N was 57% higher than the optimum N fertilization level for rice ($90kg\;N\;ha^{-1}$). Excess green manure biomass above an optimum level can be removed and utilized either for incorporation into nearby cropland or for sale as fresh forage. Therefore, it is concluded that the application rate of LSM P50% is recommendable for the maximum biomass and nitrogen production from green manure crops in paddy.

• Journal of Soil and Groundwater Environment
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• v.27 no.4
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• pp.10-21
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• 2022

In the South Korea, 47% of abandoned mines are suffering from the mining hazards such as the mine drainage (MD), the mine tailings and the waste rocks. Among them the mine drainage which has a low pH and the high concentration of heavy metals can directly contaminate rivers or soil and cause serious damages to human health. The natural/artificial treatment facilities by using neutralizers and coagulants for the mine drainage have been operated in domestic and most of heavy metals in mind drainage are precipitated and removed in the form of metal hydroxide, alumino-silicate or carbonate, generating a large amount of mine drainage treated sludge ('MDS' hereafter) by-product. The MDS has a large surface area and many functional groups, showing high efficiency on the fixation of heavy metals. The purpose of this study is to develop a ingenious heavy metal stabilizer that can effectively stabilize arsenic (As) and heavy metals in soil by recycling the MDS (two types of MDS: the acid mine drainage treated sludge (MMDS) and the coal mine drainage treated sludge (CMDS)). Various analyses, toxicity evaluations, and leaching reduction batch experiments were performed to identify the characteristics of MDS as the stabilizer for soils contaminated with As and heavy metals. As a result of batch experiments, the Pb stabilization efficiency of both of MDSs for soil A was higher than 90% and their Zn stabilization efficiencies were higher than 70%. In the case of soil B and C, which were contaminated with As, their As stabilization efficiencies were higher than 80%. Experimental results suggested that both of MDSs could be successfully applied for the As and heavy metal contaminated soil as the soil stabilizer, because of their low unit price and high stabilization efficiency for As and hevry metals.

• 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.

• Journal of Soil and Groundwater Environment
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• v.16 no.1
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• pp.19-31
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• 2011

This study had been carried out to investigate spatial and temporal variations of the concentrations of trace metals for contaminated surface water in creek affected by leachate from the tailings impoundment of the Yeonhwa II mine for about 2 years. It was also to ascertain the metal removal efficiency for potentially deleterious metals by the artificial and natural attenuation processes such as retention ponds and hydrologic mixing of uncontaminated tributaries. The concentrations of As, Pb, Cd, and Cu for leachate in the rainy season were not detected. On the other hand, the concentrations of Zn, Fe, Mn, Al, and $SO_4^{2-}$ in the rainy season for leachate were 2-66 times higher than those in the dry season, due to the oxidation of the sulfide minerals and the dissolution of the secondary minerals. The concentrations of Zn and Cd for leachate and surface water of the upper creek in the rainy season exceeded the criteria of River Water Quality and Drinking Water Quality but in the dry season, those of analyzed all the metals (As, Pb, Cd, Cu, Zn, Cd, Fe, Mn, and Al) for surface water sampled at the study area were below the criteria of River Water Quality and Drinking Water Quality. In regard of the attenuation efficiency for the concentrations of metals, Fe, Mn, Al, Zn, Cd, As, and Cu were removed highly at retention ponds, while the removal efficiency for major cations and sulfate ($SO_4^{2-}$) were related to mixing of the uncontaminated tributaries. Therefore, the major attenuation processes of the metal and sulfate contents in creek affected by leachate from a tailing dump were precipitation (accompanied by metal co-precipitation and sorption), water dilution, and neutralization.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.6
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• pp.626-634
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• 2005

The objectives of this study was to assess pollution level and contamination status on tailings and soil in the vicinity of four disused metal mines in Kangwon province. As the result of total metal concentrations analysis, the pollution degree of tailings and soil decreased in the order of Wondong > Second Yeonhwa > Sinyemi ${\fallingdotseq}$ Sangdong mines. Total metal concentrations of mine tailings in this study were $1.2{\sim}78.2$ and $1.1{\sim}80.6$ times higher than those in the background soil and the tolerable levels suggested by Kloke, respectively. From these results, we found that tailings served as contamination source of nearby soil. According to sequential extraction of metals, large proportion of heavy metals in all mine tailings existed in the form of a residual fraction, and heavy metals in non-residual form was mainly associated with Fe-Mn oxide fraction and sulfidic-organic fraction. Fe-Mn oxide fraction and sulfidic-organic fraction of heavy metals may be released into and contaminated the nearby environment under the oxidation or reduction condition in long-term. In particular, the proportions of the exchangeable and carbonate fraction of Cd in mine tailings from Second Yeonhwa mine were relatively high. This suggests that Cd may be easily released into and contaminated the nearby environment in the near time. Concentrations of heavy metals in mine tailings and the nearby soil exceeded the standard (agricultural area) of Soil Environment Conservation Law. So it was thought that remediation for mine tailings and the nearby soil is needed. The pollution indices of the samples in this study were for higher than 1.0 and the pollution degree was very serious. Priority remediation site for these mines was Wondong. As Results of danger indices, it was showed that exchangeable form in Wondong and Fe-Mn oxide form in the rest mines should be removed preferentially.

• Economic and Environmental Geology
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• v.37 no.1
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• pp.121-131
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• 2004

Removal efficiencies of soil washing and soil improvement processes to remediate farmland soils and stream deposits around Goro abandoned mine were investigated with batch and column experiments. For As-contaminated farm-land soils around Goro mine, batch tests to quantify As extraction rate from contaminated soils and lime treated contaminated soils were performed. The contaminated soil mixed with lime decreased As extraction rate less than one fourth, suggesting that the soil improvement method mixed with lime dramatically decrease As extraction rate. A storage dam will be constructed in the lower part of the main stream connected to Goro abandoned mine and the amount of As extracted from the bottom soils of reservoir could be the main source to contaminate water of reservoir. The decrease of As extraction amount from the bottom in reservoir, caused by the application of the soil improvement method was investigated from the physically simulated column experiment and results showed that As extraction rate decreased to one forty when 1％ lime mixed soil improvement was applied to contaminated soils. For contaminated stream deposits connected Goro mine, the removal efficiency of the soil washing method was investigated with batch experiments. Hydrochloric acid, citric acid, acetic acid and distilled water were used as soil washing solution and 0.01, 0.05, 0.1, 0.5, 1.0 N of washing solution were applied to extract As. When washing with 0.05 N of hydrochloric acid or citric acid, more than 99.9% of As was removed from stream deposits, suggesting that As contaminated stream deposits around Goro mine be successfully remediated with the soil washing process. Total volumes of contaminated soils and deposits needed for remediation were calculated based on three different reme-diation target concentrations and the operation cost of soil washing for calculated soil volumes was estimated. Results from this research could be directly used to make a comprehensive countermeasure to remediate contaminated area around Goro mine and also many contaminated areas similar to this research area.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.89-91
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• 2000

Polynuclear aromatic hydrocarbon (PAH) compounds are highly carcinogenic chemicals and common groundwater contaminants that are observed to persist in soils. The adherence and slow release of PAHs in soil is an obstacle to remediation and complicates the assessment of cleanup standards and risks. Biological degradation of PAHs in soil has been an area of active research because biological treatment may be less costly than conventional pumping technologies or excavation and thermal treatment. Biological degradation also offers the advantage to transform PAHs into non-toxic products such as biomass and carbon dioxide. Ample evidence exists for aerobic biodegradation of PAHs and many bacteria capable of degrading PAHs have been isolated and characterized. However, the microbial degradation of PAHs in sediments is impaired due to the anaerobic conditions that result from the typically high oxygen demand of the organic material present in the soil, the low solubility of oxygen in water, and the slow mass transfer of oxygen from overlying water to the soil environment. For these reasons, anaerobic microbial degradation technologies could help alleviate sediment PAH contamination and offer significant advantages for cost-efficient in-situ treatment. But very little is known about the potential for anaerobic degradation of PAHs in field soils. The objectives of this research were to assess: (1) the potential for biodegradation of PAH in field aged soils under denitrification conditions, (2) to assess the potential for biodegradation of naphthalene in soil microcosms under denitrifying conditions, and (3) to assess for the existence of microorganisms in field sediments capable of degrading naphthalene via denitrification. Two kinds of soils were used in this research: Harbor Point sediment (HPS-2) and Milwaukee Harbor sediment (MHS). Results presented in this seminar indicate possible degradation of PAHs in soil under denitrifying conditions. During the two months of anaerobic degradation, total PAH removal was modest probably due to both the low availability of the PAHs and competition with other more easily degradable sources of carbon in the sediments. For both Harbor Point sediment (HPS-2) and Milwaukee Harbor sediment (MHS), PAH reduction was confined to 3- and 4-ring PAHs. Comparing PAH reductions during two months of aerobic and anaerobic biotreatment of MHS, it was found that extent of PAHreduction for anaerobic treatment was compatible with that for aerobic treatment. Interestingly, removal of PAHs from sediment particle classes (by size and density) followed similar trends for aerobic and anaerobic treatment of MHS. The majority of the PAHs removed during biotreatment came from the clay/silt fraction. In an earlier study it was shown that PAHs associated with the clay/silt fraction in MHS were more available than PAHs associated with coal-derived fraction. Therefore, although total PAH reductions were small, the removal of PAHs from the more easily available sediment fraction (clay/silt) may result in a significant environmental benefit owing to a reduction in total PAH bioavailability. By using naphthalene as a model PAH compound, biodegradation of naphthalene under denitrifying condition was assessed in microcosms containing MHS. Naphthalene spiked into MHS was degraded below detection limit within 20 days with the accompanying reduction of nitrate. With repeated addition of naphthalene and nitrate, naphthalene degradation under nitrate reducing conditions was stable over one month. Nitrite, one of the intermediates of denitrification was detected during the incubation. Also the denitrification activity of the enrichment culture from MHS slurries was verified by monitoring the production of nitrogen gas in solid fluorescence denitrification medium. Microorganisms capable of degrading naphthalene via denitrification were isolated from this enrichment culture.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.4
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• pp.234-239
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• 2015

Various leaching tests were applied to the soil affected by accidental leakage of HF in an industrial area in Korea. Three different leaching methods including pH-stat, continuous batch leaching, and column tests were adopted to assess leaching characteristics and mobility of fluorine(F) in soil and the potential risks to ecosystem. Both natural and spiked samples were used for the leaching tests. F concentrations in the batch tests increased by leaching rapidly in the early stage of leaching and then maintained rather constant levels. Column leaching test also show similar result to that of the batch test. pH also controlled the leaching behavior of the soil. With increasing pH, more F was released in the pH-stat test. This is mainly due to the competition and exchange with hydroxyl ions, as pH increase to the alkaline range. Most of the F released by the accident seem to have removed in the very early stage of leaching, whereas some natural proportion from soil minerals are thought to have been released very slowly. Therefore, little F released during the accident remained, based on the results of this study on the samples after two years of the accident. We could conclude that soil contaminated by external effects such as chemical accidents should be managed immediately, especially with F.

• Horticultural Science & Technology
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• v.28 no.5
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• pp.728-734
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• 2010

We studied the accumulation and partitioning of dry weight (DW) and nitrogen (N) in different parts of field-grown 'Fuyu' persimmon to elucidate that the foliar applications of supplemental N in June or September compared favorably with the traditional soil application in securing leaf area and fruit production. We also estimated the proportion of N permanently removed from the tree at the end of a growing season. Urea was applied either to leaves in June and/or September or to the soil in June and September for three consecutive years, and the trees were excavated in November for analyses. Total DW ranged from 4.2-4.8, 8.7-9.2, and 17.1-21.5 kg in a 4-, 5-, and 6-year-old tree, respectively, without statistical difference among the four treatments. Of the total DW, 3.3-10.2% was in shoots, 5.7-10.5% in leaves, 8.3-31.4% in aerial woods, 13.0-27.0% in root, and 28.0-59.3% in fruits. As the trees became more productive, DW proportion of fruits significantly affected that of the root: in 6-year-old trees, root DW accounted for only 10.6-15.8% of the tree total when fruit DW accounted for 50-60%. N contents ranged from 24.6-28.3, 48.3-53.5, and 98.3-122.6 g in a 4-, 5-, and 6-year-old trees, respectively, without statistical difference among the treatments. Of the total N, 6.2-11.5% was in shoots, 16.7-24.3% in leaves, 17.6-23.5% in aerial woods, 17.2-37.5% in roots, and 16.9-34.4% in fruits. As in DW, the increase in the proportion of N in fruits decreased in the root most significantly. Application methods for supplemental N did not affect the proportion of DW and N removed from the tree through abscising leaves and harvested fruits. Percentage of DW removal was 41 in 4- and 5-year-old trees, but it was 61 in more productive 6-year-old trees; that of N was 39, 43, and 49%, respectively. No significant changes in the contents of DW and N in field-grown trees, as well as their percentages removed from the tree at the end of the season, demonstrated that foliar application of supplemental N was as good as soil applications with much less N.

• Economic and Environmental Geology
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• v.37 no.1
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• pp.61-72
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• 2004

The soil samples were collected from the paddy field near the mine tailing dumps in the abandoned Duckum mine in Korea. In the laboratory, the soil solution was extracted from the soil using centrifuge, and analysed for the chemical composition. Physical and chemical soil properties were also analysed. Kaolinite is the main clay minerals in the paddy soil and the CEC value is therefore relatively low. Nearly all soil samples show enrichment in their trace elemental concentrations(Cd, Cu, Pb and Zn) compared with natural background level. Some soil samples exceed the soil remediation intervention values for Cd, Pb and Zn and target value for Cu, when compared with Dutch standard, whereas As, Ni and Cr are in normal range. Lead concentrations in some samples near the mine tailing dumps also exceed the standard for remediation act for agricultural area set by Korean soil conservation law. The trace elemental concentrations are higher in the paddy soil nearer the mine tailing dumps and lower for the samples from distance. Similar trend with distance is found for the soil solution chemistry but the decrease with distance from the mine tailing dumps are sharper than the changes in soil chemistry. Cadmium, Cu and Pb concentrations in the soil solution are very low, ranging from a tenth and hundredths to a maximum of several mg/l, whereas their concentrations in soils are highly enriched for natural background. Most of the trace elements are thought to be either removed by reduced iron sulphides or iron oxides, depending on the redox changes. Geochemical equilibrium modelling indicate the presence of solubility controlling solid phases for Cd and Pb, whereas Zn and Cu might have been controlled by adsorption/desorption processes. Although pollutants migration through solution phase are thought to be limited by adsorption onto various Fe, Mn solid phases, the pollutants exist as easily releasable fractions such as exchangeable site. In this case, the paddy soil would act as pollutant pool, which will supply to plants in situ. whenever the geochemical conditions favour.