• 한국토양비료학회지
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• 제48권1호
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• pp.30-35
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• 2015

This study was conducted to investigate investigated the effect of nitrogen fertilizer on nitrate concentration in soil solution and to determine the relationship between yield and nitrate concentration in soil solution for cucumber cultivation under plastic film house. Nitrogen as urea was applied at rates of 0, 120, 240, 360, and $480kg\;N\;ha^{-1}$ as an additional fertilizer by trickle irrigation during cucumber cultivation. Monitoring of nitrate concentration in soil solution was investigated using porous cups at 25 cm depth under soil surface. Nitrate concentration in soil solution increased with increasing the rate of additional nitrogen. Correlation coefficient between EC value and nitrate concentration was positive in soil and soil solution (p<0.05). An additional nitrogen of about $300kg\;ha^{-1}$ was shown the highest yield of cucumber, and improved yield by 5% compared to N recommendation of $240kg\;N\;ha^{-1}$. The highest yield was determined at nitrate concentration of $82mg\;L^{-1}$ in soil solution by regression equation ($Y=74.2+0.73X+0.000504X^2$, $R^2=0.629^*$). These results means indicate that nitrate concentration in soil solution would be useful method to rapid determination for additional nitrogen during cucumber cultivation under plastic film house.

• 농업과학연구
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• 제41권4호
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• pp.399-404
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• 2014

Soil moisture is an important factor for the availability and circulation of nutrients in arable soil. The purpose of this study was to set thresholds moisture content on soil nitrate concentration in the solution for real-time diagnosis. Sandy loam, silt loam, and sandy loam was filled with $1.2g\;cm^{-3}$ at Wagner pots, 0, 100, and $200mg\;L^{-1}$ of $KNO_3$ was saturated. Nitrate in standard solution was recovered about 95% by passing the porous cup. Nitrate concentrations in sampling of soil solution were examined by using a porous cup. The soil solution was higher in accordance with sandy loam> silt loam> clay loam, limited water filled pore space for sampling soil solution was 33.7, 56.4, and 62.2%, respectively. Nitrate concentration in the soil solution was negligible at sandy loam and silt loam during sampling periods, which was decreased about 50~82% in clay loam compared to the initial $NO_3$-N concentration in the saturated $KNO_3$ solution. Over limitation of soil solution sampling, soil EC and $NO_3$-N content were increased with the saturated $NO_3$-N concentration, regardless of soil texture (p<0.05). Conclusively, soil solution by using a porous cup was possible, regardless of the soil texture, which was useful for the diagnosis in nitrate concentration of soil solution. However, because nitrate concentration of soil solution in a clay loam changes, it was necessary for careful attention in order to take advantage for the real-time diagnosis of nitrogen management in soil.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 총회 및 춘계학술발표회
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• pp.418-421
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• 2003

Surfactant enhanced in-situ soil flushing was peformed to remediate the soil and groundwater at an oil contaminated site, and the effluent solution was treated by the chemical treatment process including DAF(Dissolved Air Flotation). A section from the contaminated site(4.5m$\times$4.5m$\times$6.0m) was selected for the research, which was composed of heterogeneous sandy and silt-sandy soils with average Hydraulic conductivity of 2.0$\times$10$^{-4}$ cm/sec. Two percent of sorbitan monooleate(POE 20) and 0.07% of iso-prophyl alcohol were mixed for the surfactant solution and 3 pore volumes of surfactant solution were injected to remove oil from the contaminant section. Four injection wells and two extraction wells were built in the section to flush surfactant solution. Water samples taken from extraction wells and the storage tank were analyzed by GC(gas-chromatography) for TPH concentration with different time. Five pore volumes of solution were extracted while TPH concentration in soil and groundwater at the section were below the Waste Water Discharge Limit(WWDL). Total 18.5kg of oil (TPH) was removed from the section. The concentration of heavy metals in the effluent solution also increased with the increase of TPH concentration, suggesting that the surfactant enhanced in-situ flushing be available to remove not only oil but heavy metals from contaminated sites. Results suggest that in-situ soil flushing and chemical treatment process including DAF could be a successful process to remediate contaminated sites distributed in Korea.

• 한국의류학회지
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• 제35권10호
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• pp.1242-1251
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• 2011

This study investigates the effect of mixed characteristics of oily soil such as mixed ratio, polarity of oily soil on contact angle of fabric, removal of oily and particulate soil from PET fabric in oily/particulate soil mixed system. The contact angle of fabric in the surfactant solution with suspended oily soil was examined as a fundamental environment of detergency of soil from fabrics. Detergency was investigated as function of mixed ratios of oily/ particulate soil, type of oily soil, surfactants concentration, surfactant type and temperature of detergency in surfactant solution. The contact angle of fabric in surfactant solution sharply increased with mixing nonpolar oily soil; in addition, the contact angle slightly increased with increasing contents of oily soil and decreased with increasing surfactant concentration. The removal of oily and particulate soil from fabric was higher in the solution mixed with polar versus nonpolar oily soil. The detergency increased with increasing surfactant concentration and the increased temperature of surfactants solution that were relatively improved in NPE compared to DBS solutions, The results indicated that the detergency of oily and particulate soil showed a similar trend in oily/ particulate mixed soil systems. The general contact angle of fabric was well related with the detergency of oily and particulate soil in oily/particulate mixed soil system, therefore, the primary factor determining the detergency of soil in oily/particulate mixed soil system may be the contact angle of fabric caused by wettability.

• 한국지하수토양환경학회지:지하수토양환경
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• 제18권6호
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• pp.38-47
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• 2013

This study was performed to identify the optimal operating conditions and to evaluate the xylene removal efficiency, applying in-situ soil flushing with the low concentrated solution of 'Tween 80' at the xylene contaminated site. The pilot scale test site ($5m{\times}5m{\times}3m$), was mainly composed of 'sandy loam', with the average hydraulic conductivity of $9.1{\times}10^{-4}cm\;s^{-1}$. The average xylene concentration of the site was 42.1 mg $kg^{-1}$, which was more than 2.5 times higher than Korea soil pollution warning limit (15 mg $kg^{-1}$). For the soil flushing, 7,800 L of 0.1~0.2% surfactant solution was injected into three injection wells at the average injection time of 9 hr $d^{-1}$ for 10 days, followed by the additional only groundwater injection of 6,000 L. The same amount of the effluent solution was extracted from three extraction wells. From the analysis for xylene concentration of all effluent at 3 extraction wells, total 166 g of xylene was removed by in-situ surfactant flushing. Even though the residual xylene concentrations of 7 soil sampling locations in the test site were different due to the soil heterogeneity, from the comparison of xylene concentration at 7 locations before/after the feasibility test, 53.9% of the initial xylene in the site was removed from three extraction wells (mainly Ext-N and Ext-M well). The results showed that the in-situ soil flushing by using low concentrated 'Tween 80' solution had a great potential to remediate the xylene contaminated site.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2002년도 총회 및 춘계학술발표회
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• pp.209-212
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• 2002

Main radionuclides of the soil waste stored in Korea Atomic Energy Research Institute are Co-60 and Cs-137. Moisture content of soil is 12%, pH of soil is 5.8, and content of organic matter is 2.2 %. Radioactive concentrations of the soil particle size of which is less than 0.063mm and soil in the drum surface of which is more than radiation dose rate 0.05mR/hr are higher. Meanwhile, radioactive concentration of soil in the drum surface of which is less than radiation dose rate 0.02 mR/hr are mostly lower. On using the mixing solution of ammonium sulfate and citric acid, 62% Co was removed from soil and 41% Cs was removed. Also, on using the mixing solution of ammonium nitrate and citric acid, 61% Co was removed from soil and 39% Cs was removed, and on using the mixing solution of ammonium potassium oxalate, 36% Co was removed and only 3% Cs was removed. And on using only water, removal efficiency is less than 5%.

• 한국환경농학회지
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• 제17권4호
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• pp.341-345
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• 1998

Soil solutions were collected by zero-tension lysimeters at Kwangju, Kyunggi Province to estimate differences in ion concentration among species and horizons. Zero-tension lysimeters were installed in O, A, and B horizons in Larix leptolepis, Pinus koraiensis, and Quercus mongolica stands. Soil solution samples were collected from September 1996 through August 1998 and analyzed for $K^+$, $NA^+$, $NH_4^+$, $Mg^{2+}$, $Ca^{2+}$, $Al^{3+}$, $Cl^-$, $SO_4^{2-}$, $NO_3^-$, and $PO_4^{3-}$. The experimental site had high nitrogen loading from the atmosphere, and $NO_3^-$ was positively correlated with $K^+$ and $Mg^{2+}$. However, $NO_3^-$ and $NH_4^+$ showed a positive correlation only in the O horizon of Q. mongolica stand. Mg^(2+) deficit in the soil was predicted owing to the positive relationship of $Mg^{2+}$ with $NO_3^-$. Concentrations of $K^+$ and $Ca^{2+}$in soil solution were estimated higher in L. leptolepis than in other stands because of high leaching from the plant. Concentration of $Al^{3+}$ in soil solution was negatively correlated with soil solution pH. Mean soil solution pH of A and B horizons in P. koraiensis was lower than 4.7, however the $Al^{3+}$ concentration was lower than the toxic level to plants.

• 한국지하수토양환경학회지:지하수토양환경
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• 제18권7호
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• pp.63-72
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• 2013

This study estimated stabilization efficiency of As and heavy metal contaminated agricultural soil in abandoned mine through pot experiment. Also contaminants uptake of plant (lettuce) was compared as function of amendment (limestone, steelmaking slag and the mixture of these) addition. In soil solution analysis, concentration of contaminants in soil solutions which added limestone or steelmaking slag were lower than that of the mixture. Especially in As analysis, concentration with 5% (wt) addition of steelmaking slag showed the lowest value among those with other amendments. This seems that As stabilization happens through Fe adsorption during precipitation of Fe by pH increasing. Leachability of As in stabilized soil by TCLP was represented similar result with soil solution analysis. However leachability of heavy metals in stabilized soil was similar with that of non-stabilized soil due to dissolution of alkali precipitant by weak acid. Contaminants uptake rate by plant was also lower when limestone or steelmaking slag was used. However this study revealed that concentration of contaminants in soil solution didn't affect to the uptake rate of plant directly. Because lower $R^2$ (coefficient of determination) was represented in linear regression analysis between soil solution and plant.

• Applied Biological Chemistry
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• 제41권8호
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• pp.583-586
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• 1998

Porous ceramic cups are used for monitoring ion concentration in soil solutions in various time course and depth. A soil solution sampler was constructed in laboratory by inserting pliable perfluoroalkoxy(PFA) tubings into porous cup through holes in PVC rod segment which plugged top opening of the porous cup. The system was installed in drip irrigated soil in a vertical position, and nitrogen movement below the drip basin was monitored. To collect soil solution, vacuum in the cup was applied with a hand vacuum pump. The samples obtained were sufficient enough to run quantitative analyses for a number of chemicals. Nitrogen transformation and movement could be well defined, and the system seemed to be relevant to the other soil solution samplers in monitoring chemical movement in soil. Although this system has general deficiencies found in the other samplers using ceramic cup, it could be easily constructed at a low cost. Since the tubing was pliable, the cups could be installed in horizontal position, and this allows installations of the cups at more precise depth increments and also more precise samplings of soil solution at each depth.

• 한국의류산업학회지
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• 제13권5호
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• pp.790-796
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• 2011

This study was designed to investigate the influence of ratio of anionic/nonionic surfactant mixture on detergency of particulate soil under various solutions. The detergency of the particulate soil was determined by adhesion of particle to fabric and its removal from fabric separately. The PET fabric and ${\alpha}-Fe_2O_3$were used as materials of textile and model of particulate soil, respectively. The detergency was investigated as a function of surfactants concentration, ionic strength, kinds of electrolyte and mole numbers of oxyethylene ether of nonionic surfactant in different ratio of anionic/nonionic surfactant mixture. Although some deviations exist, the adhesion of particle to fabric generally increased with decreasing its removal from fabric. The detergency of particulate soil on PET fabric was relatively higher in anionic/nonionic surfactant mixed solution than in each single surfactant solution, but the influence of ratio of anionic/nonionic surfactant mixture on detergency of particulate soil was low. Generally the detergency of particulate soil on fabric was at its maximum at 0.1% surfactant concentration, $1{\times}10^{-3}$ ionic strength, $Na_5P_3O_{10}$ electrolytes and 10 mole numbers of oxyethylene ether of nonionic surfactant, regardless of ratio of anionic/nonionic surfactant mixture.