• Korean Journal of Soil Science and Fertilizer
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• v.48 no.5
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• pp.372-378
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• 2015

Growing crops under different soil textures may affect crop growth and yield because of soil N availability, soil N leaching, and plant N uptake. The objective of this study was to evaluate effects of three different soils (sandy loam, loam, and clay loam) on cucumber (Cucumis sativus L.) yield, nitrogen (N) use efficiency (NUE), and water use efficiency (WUE) by subsurface drip fertigation in the greenhouse. Three different soil textures are sandy loam, loam, and clay loam with 3 replications. The dimension of each lysimeter was $1.0m(W){\times}1.5m(L){\times}1.0m(H)$. Cucumber was transplanted on April $8^{th}$ and Aug $16^{th}$ in 2011. The subsurface drip line and tensiometer was installed at 30 and 20 cm soil depth, respectively. An irrigation with $100mg\;NL^{-1}$ concentration was automatically applied when the tensiometer reading was 10 kPa. Volumetric soil water content for cucumber cultivation was the highest in 30 cm soil depth regardless of soil texture and was lowered when soil depth was deeper. The volumetric soil water contents at soil depths of 10, 30, 50, and 70 cm were the highest at clay loam, followed by loam, and sandy loam. The growth of cucumber at the $50^{th}$ day after transplanting was the lowest at sandy loam. Cucumber fruit yields were similar for all three soil textures. The highest amount of water use at sandy loam was observed. Nitrogen and water use efficiencies for cucumber were higher for clay loam, followed by loam and sandy loam, while the amount of N leaching was the greatest under sandy loam, followed by loam, and clay loam. Overall, growing cucumber on either loam or clay loam is better than sandy loam if subsurface drip fertigation is used in the greenhouse.

• Journal of Soil and Groundwater Environment
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• v.10 no.3
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• pp.1-8
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• 2005

Fractional compositions and leaching potentials of Cd, Cu and Zn were investigated in the soils which had been disposed with the metal processing wastes, tungsten mine tailings and low quality coal mine area. Total concentrations of metals in these soils were higher than in non-polluted paddy and upland soils. Fractions of Cd, Cu and Zn were mostly reducible, organic and residual forms, but varied with origins of wastes. Residual fraction was a predominant form in the nonpolluted soils. Leaching potentials of metals were higher in polluted soils than in non-polluted soils. Metals leached were higher at pH 4.0 than 7.0 and increased with the duration time. After 25 to 35 hrs, metals released from soils reached a pseudoequilibrium. Leaching potential of metals in non-polluted soils was low due to high percentage of residual fractions.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2003.11a
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• pp.32-37
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• 2003

The amount of 4,500 drums of soil waste are temporarily stored in KAERI. In order to develop a technology for safe treatment of the soil waste, a number of tests were performed by applying cement and polymer as solidifier. Immobilization specimens were adequately made by mixing soil waste with cement or polymer Compressive strength and leaching tests were performed in order to see the fulfillment to standard of disposal following the storage. A compressive strength, about 5,300psi was obtained from both solidifiers of cement containing 40% of soil waste and polymer containing 60%. The obtained leaching index was larger than 11, which was satisfied with the relevant standard. It was shown that the integrity of the solidified waste much depends on homogenization in solidifying process and hardness of the specimen. Volume reduction of solidified waste with polymer was better than that of cement by 20%.

• The Korean Journal of Pesticide Science
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• v.8 no.1
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• pp.46-53
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• 2004

Adsorption and leaching characteristics of hexaconazole were investigated to estimate the mobility potential of the compound in the soil environment. As well fitted to Freundlich adsorption isotherm, adsorptivity of hexaconazole, ranged 10.56-18.01 of Kf values, seemed high enough to be immobile in soil. This chemical leached more faster from fresh soil with rice plants. Most of $^{14}C$ (86-99% of originally applied $^{14}C$) was distributed within 5 cm soil depth from surface. Considering Koc values of 1,400-1,552 and Groundwater Ubiquity Score (GUS) indices of 1.25-1.35 as well as results from leaching experiment with soil column, hexaconazole falls into the category of improbable leacher, suggesting little mobility in soil.

• Korean Journal of Environmental Agriculture
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• v.25 no.1
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• pp.58-63
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• 2006

In order to elucidate the adsorption and leaching characteristics of the insecticide imidacloprid in two types of paddy soils near Suwon, this experiment was carried out with $[^{14}C]$imidacloprid as a radiotracer. In an adsorption study conducted using $[^{14}C]$imidacloprid in 2 test soils, the adsorption coefficient was higher in soil A $(K_f\;2.6)$ than that in soil B $(K_f\;1.7)$. As calculated from Freundlich constant, distribution coefficients and half lives in soils, GUS indices showed low leachabilities of imidacloprid treated on the paddy soils into the groundwater. The amount of imidacloprid leached from the soil columns during the 4 weeks of leaching was less than 2% of the originally treated $^{14}C$. In the leaching test the amounts of $^{14}C$ activities distributed in the soil layer of 0-10 cm were more than 80% of the originally tented $^{14}C$ and those in rice plants were less than 3% of the originally treated $^{14}C$, suggesting that imidacloprid has very low teachability and bioavailability.

• Journal of Environmental Science International
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• v.26 no.6
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• pp.797-802
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• 2017

This study aimed to remove organic matter and heavy metals that could affect the recycling of soils contaminated by heavy metals, by means of electrolysis, carried out simultaneously with the leaching of the soil. To ensure better experimental equipment, a soil electrolysis apparatus, equipped with spiral paddles, was used to agitate the heavy-metal-contaminated soil effectively. The heavy-metal-contaminated soil was electrolyzed by varying the voltage to 5 V(Condition 1), 15 V(Condition 2), and 20 V(Condition 3), under the optimal operating conditions of the electrolysis apparatus, as determined through previous studies. The results showed that the pH of the electrolyte solution and the heavy-metal-contaminated soil, after electrolysis, tended to decrease with an increase in voltage. The highest removal efficiencies of TOC and $COD_{Cr}$ were 18.8% and 29.1%, 38.8% and 4.2%, and 33.3% and 50.0%, under conditions 1, 2 and 3, respectively. Heavy metals such as Cd and As were not detected in this experiment. The removal efficiencies of Cu, Pb and Cr were 4.7%, 8.3% and 2.1%, respectively, under Condition 1, while they were 42.9%, 15.2% and 22.1%, respectively, under Condition 2, and 4.7%, 23.0%, and 24.9%, respectively, under Condition 3. These results suggest that varying the voltage with the soil electrolysis apparatus for removing contaminants for the recycling of heavy-metal-contaminated soil allows the selective removal of contaminants. Therefore, the results of this study can be valuable as basic data for future studies on soil remediation.

• Journal of Soil and Groundwater Environment
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• v.23 no.6
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• pp.46-53
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• 2018

Mobility reduction of 2,4,6-trinitrotoluene (TNT) was tested by amending monopotassium phosphate (MKP) and montmorillonite to a firing range soil contaminated with TNT. While addition of MKP enhanced sorption of TNT on soil matrix, and combined use of MKP with montmorillonite significantly decreased desorption of TNT as well as remarkably increased the TNT sorption. Montmorillonite amendment by 5% of soil mass resulted in TNT desorption of 0.12 mg/kg from soil loaded with 9.93 mg/kg-TNT. The decrease of TNT desorption was proportional to the amount of montmorillonite amended. At 10 and 15% amendment, only 0.79 and 1.23 mg/kg-TNT was desorbed from 29.33 and 48.80 mg/kg-TNT. In addition, the leaching of TNT with synthetic precipitation leaching procedure (SPLP) and hydroxypropyl-${\beta}$-cyclodextrin (HPCD) decreased, indicating that TNT in MKP/montmorillonite-treated soil became more stable and less leachable. The results demonstrate that addition of MKP and montmorillonite to TNT-contaminated soil reduces the mobility of TNT from soil not only by increasing TNT sorption, but also decreasing TNT desorption. It was found that MKP and montmorillonite amendments by 5 and 10% of soil mass, respectively, were optimal for reducing the mobility of soil TNT.

• The Korean Journal of Pesticide Science
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• v.6 no.4
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• pp.309-319
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• 2002

Soil adsorption study was carried out to define the mobility of pesticides or to evaluate leaching potential in soils. Five pesticides including ethoprophos, procymidone, iprobenfos, isoprothiolane, and butachlor were subjected to optimized adsorption experiment protocol for three types of cultivation soils. Freundlich adsorption coefficients (K) were ranged $0.35{\sim}0.95$ for ethoprophos, $0.98{\sim}2.2$ for iprobenfos, $1.2{\sim}4.3$ for procymidone, $1.5{\sim}3.5$ for isoprothiolane and $7.9{\sim}19$ for butachlor in three soils. Based on Koc values, ethoprophos was classified as mobile, iprobenfos, isoprothiolane and procymidone as moderately mobile and butachlor as slightly mobile. Two evaluation methods, Groundwater Ubiquity Score (GUS) index and standard indices of soil-chemical adsorption and biodegradation, were used for the estimation of pesticide leaching potential. Leachability of isoprothiolane and iprobenfos were evaluated as moderate, ethoprophos as a little potential, while butachlor and procymidone showed very low leaching potential. The leaching potential of pesticides was essentially determined on the basis of intrinsic properties of the pesticides and environmental properties. Among the soil properties, organic matter gave a great influence on the leachability of soils. Therefore, leachabilities of pesticides were expected less in loam with relatively higher organic matter than clay loam with lower organic matter.

• Analytical Science and Technology
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• v.21 no.1
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• pp.1-8
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• 2008

This study was conducted to investigate the characteristics of the leaching of metal components from CCA-treated wood during outdoor exposure. CCA-treated wood specimens were placed horizontally or buried vertically into the soil, and then exposed to the natural environment for a year. Wood samples were collected from the side of the horizontal wood specimens using a drill and saw dust samples were collected at the end of the exposure. Soil samples were also obtained around the wood specimens and at different depths of the posts. Wood and soil samples were analyzed for metals using an atomic absorption spectrometer. Monthly metal concentrations varied greatly and more metals were released when wood specimens were exposed vertically than horizontally. Arsenic was released from the wood by 80 % of the intial content. In addition, more leaching was observed from the zone below the ground than above the ground, and soil around the posts was contaminated with metals released from CCA-treated wood.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.4 no.4
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• pp.365-372
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• 2006

A dynamic compartment model is presented to predict the contamination level of agricultural plant by $^{137}C_s$ as a result of a soil deposition. The model considered the processes of a percolation, soil mixing by a plowing before transplanting, plant uptake, leaching to a deep soil, and fixation to a clay mineral. The effects of the soil properties (pH, clay mineral, organic matter content, and exchangeable K), which are spatially varied, on a plant uptake and the leaching rates of $^{137}C_s$ in a root zone soil were modeled by the Absalom model. To test the validity of the model, the $^{137}C_s$ aggregated transfer factors(TFa) for rice plants were compared with those observed from some simulated $^{137}C_s$ soil deposition experiments, which were carried out with respect to rice plants cultivated in seventeen paddy soils of different properties for two consecutive years. Observed $^{137}C_s$ TFa values of the rice plants did not show an evident trend for the pH and clay content of the soil properties, while they increased with an increasing organic matter content or a decreasing exchangeable K concentration. Predicted $^{137}C_s$ TFa values of the rice plants were found to be comparable with those observed.