• The Korean Journal of Pesticide Science
• /
• v.10 no.4
• /
• pp.272-278
• /
• 2006

Movement of pesticides applied for crop protection to the non-target environmental compartments has increasingly concerned in recent. A special review on groundwater leaching potential of pesticides registered in Korea was done by using the data submitted on half-life and adsorption of the pesticides in/on soil. Groundwater ubiquity score(GUS) of pesticides as a leaching potential was calculated by using domestic trial data on pesticide half-life in paddy or upland soils and Koc data bases of Oregon State University (OSU), British Pesticide Safety Directorate and Sweden. Of total 382 pesticides reviewed, domestic half-lives of 107 pesticides were for paddy soil and 297 pesticides for upland soil. And total 317 Koc values were collected 148 pesticides from OSU DB and 276 pesticides from UK/Sweden DB. Very highly leachable pesticides were 18 and highly leachable pesticides were 44 among 313 pesticides classified by GUS.

• Korean Journal of Soil Science and Fertilizer
• /
• v.31 no.4
• /
• pp.407-413
• /
• 1998

The influence of the anion composition of simulated acid rain on cation leaching of two soils with different surface charge properties was examined. Four mixtures of mole ratio of $SO_4:NO_3$(1:0, 2:1, 1:1, 0:1) with pH 2.0 simulated acid rain were applied to an Inceptisols(Gyuam series) and Andisols(Pyeongdae series). The Andisols had higher $SO_4{^{2-}}$ adsorption capacity than the Inceptisols because of its higher point of zero charge(PZC, pH 6.5) than Inceptisols(PZC pH 3.1). Cation leaching in Andisols varied directly with the $NO_3$ content of the leaching input due to higher mobility of $NO_3$ compared with $SO_4$ that was absorbed. The pH of the Andisols was higher with the addition of $Na_2SO_4$ than the addition of $NaNO_3$ indicating that this soil behaves as a base and has a high $SO_4$ adsorption capacity. The relative $NO_3{^-}/SO_4{^{2-}}$ content input had no effect on cation leaching of the Inceptisols. Amounts of leaching on the Andisols by simulated acid rain were higher than Inceptisols. This experiment explained that anion composition of acid rain plays a significant role in the cation leaching of soils which are able to adsorb $SO_4$.

• Journal of the Korean GEO-environmental Society
• /
• v.11 no.12
• /
• pp.13-18
• /
• 2010

This study was made on the fact that the environmental impact and durability of the recently developed alkali silicasol chemical grout material. The grout material used for this study was designed to understand its environmental impact and durability through the SEM, chemical resistance test, leaching test, permeability test. In order to compare with the engineering characteristics regarding alkali silicasol grout material and sodium silicate grout material. As a result of SEM, the surface and internal tissues of alkali silicasol grout material could be identified to be denser than those of sodium silicate. As a result of leaching test the adaptability was identified as grout material as it had proved to be an ecological material owing to the total amount of the element to be leached being extremely little. As a result of permeability test it is judged that it is possible to apply the silicasol to the site in the place requiring the water cut-off as the silicasol.

• Korean Journal of Environmental Agriculture
• /
• v.24 no.4
• /
• pp.350-357
• /
• 2005

This study was conducted to investigate the downward mobility of pesticides using soil columns and to compare the experimental results with values predicted from Convective mobility test model. Nine pesticides such as metolcarb, molinate, fanobucarb, isazofos, diazinon, fenitrothion, dimepiperate, parathion and chlorpyrifos-methyl were used for leaching test in soil column for four soils; Jungdong (upland soil), Gangseo (paddy soil), Yesan (forest soil), and Sineom(upland, volcanic ash-derived soil) series. The peak concentrations leached from 10 cm-columns of three soils except Sineom series ranged 6.5 to 12.6 mg/L for metolcarb, 2.6 to 5.0 mg/L for molinate, 4.5 to 7.8 mg/L for fenobucarb, 0.39 to 1.36 mg/L for dimepiperate, 1.1 to 4.6 mg/L for isazofos, 0.01 to 0.14 mg/L for diazinon, lower than 0.01 to 0.70 mg/L for fenitrothion and lower than 0.01 to 0.44 mg/L for parathion. But chlorpyrifos-methyl was not leached from any soil columns. Elution volumes to reach the peak of metolcarb, molinate, fenobucarb, isazofos, diazinon, and dimepiperate in the leachate ranged 1.1 to 2.1 pore volume (PV), 1.6 to 3.3 PV, 1.6 to 3.3 PV, 2.1 to 4.4 PV, 6 to 15 PV, and 8 to 21 PV, respectively. On the same water flux conditions, convection times estimated by Convective mobility test model were coincided with results from soil column test in most of the soil-pesticide combinations applied. Based on convection times estimated by the model at standard conditions (water flux 1 cm/day), metolcarb was classified as most mobile, molinate, fenobucarb and isazofos as mobile or most mobile, dimepiperate as moderately mobile or mobile, diazinon as mobile, fenitrothion and parathion as slightly mobile or mobile and chlorpyrifos-methyl as immobile or slightly mobile.

• Korean Journal of Environmental Agriculture
• /
• v.11 no.2
• /
• pp.125-132
• /
• 1992

This study was conducted to know degradation products of the synthetic pyrethroid insecticide bifenthrin under soil, aqueous solution and UV-light irradation, and know its movement by leaching in soil. The major degradation product of bifenthrin was identified with 2-methylbiphenyl -3-y1 methanol by HPLC, UV, Mass and NMR under soil, aqueous solution and UV-light irradiation, The main degradation route was hydrolysis of the ester linkage. On exposure to UV-light, bifenthrin was decomposed almost completely in concentrations of 10 and 100 ppm in 24 hr but decomposed about 80% in 1,000 ppm. Bifenthrin was immobile in soil column system and on soil thin-layer chromatography system. Mostly bifenthrin remained in the 0-2.0㎝ layer of soil column and soil TLC.

• The Korean Journal of Pesticide Science
• /
• v.8 no.1
• /
• pp.46-53
• /
• 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 CROP SCIENCE
• /
• v.46 no.3
• /
• pp.253-259
• /
• 2001

The purpose of this study was loused on understanding of uptake of nutrients by plants, the behaviors of nutrients in soil and the possibility of leaching loss when N fertilizer (urea) and mature 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: fellow, fellow with weeding, cropping without fertilizer and compost, three N fertilizer soil surface applications (16, 32, and 64 kg/10a), three N fertilizer and compost soil surface applications (16+800i 32+1600, and 64+3200 kg/10a), two water dissolved N fertilizer applications(16 and 32 kg/10a), and low and high plant densities. The growth of corn (preceding crop) and potatoes (succeeding crop) and leaching loss were determined during the experimental period. The amount of leachate from lysimeter was remarkably greater at bare conditions than at cropping conditions for corn and potatoes. The N content of plants (corn and potatoes) tended to increase as fertilizer rate increased. Fertilization of urea dissolved in water to soil was more efficient than surface fertilization for the growth, yield, and the N uptake N of corn and potatoes. There were no differences in dry matter yield of plants between medium and high N rates, but N, Ca, K and Mg concentrations of plants were higher at higher N rates. There were significant correlations between N uptake and each of Ca, K and Mg uptakes in corn and potatoes. Total N uptake by plants increased with increased N fertilizer and compost applications. Plane absorbed 54.9% of applied N at low N rate and 31.0 to 34.0% at high N rates. The proportion of N leaching losses was lower at low N rate and high plant density.

• Korean Journal of Environmental Agriculture
• /
• v.16 no.1
• /
• pp.72-79
• /
• 1997

Adsorption, leaching, and retention of the Flupyrazofos(KH-502), a new active ingredient for insecticide, in the soils under laborarory and field conditions were investigated to provide the basic data for the safety use and to assess a secondary impact of this insecticide on soil and water environments. A significant power function relation was found between the adsorbed KH-502 and time, representing that 45% of the added KH-502 was adsorbed within 30 min. but a quasiequilibrium was reached after 6 to 12 hr with a slower adsorption. Adsorption phenomena followed th first-order kinetics and time required for 50% adsorption was 5.8 hr. The equilibrium adsorption isotherm was explained by the Freundlich equation and was classified as S-type. The amounts of KH-502 leached through the soil column (C) as compared to initial conc. ($C_0$) were very low and these relative concentrations ($C/C_0$) were 0.073 and 0.017 in SL and CL soils, respectively. The residual conc. of KH-502 in the surface soil was comparatively low and decreased with time. Half-lives of KH-502 in the surface soil was comparatively low and decreased with time. Half-lives of KH-502 under the field conditions were estimated to be 20 and 18 days in the SL and CL soils, respectively. The KH-502 cone, transported to the subsurface soils was extremely low. These results demonstrate that KH-502 has a low pollution risk potential to the surrounding environment as far as it is used following the recommended guideline.

• Korean Journal of Environmental Agriculture
• /
• v.25 no.1
• /
• pp.58-63
• /
• 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 the Korean Wood Science and Technology
• /
• v.43 no.4
• /
• pp.504-510
• /
• 2015

This research was performed to evaluate soil contamination caused by copper depleted from ACQ-treated wood. Three years after the exposure of ACQ-treated wood in the field test sites, soil samples around the treated wood were collected and analyzed for the copper amount and distribution through soil. Soils around the deck posts installed in five different neighborhood parks located in Chonnam and Gyeongnam were investigated for copper contents. The results of the field test showed that the amount of copper leached from the end surface of treated wood buried under soil was more than 1.5 times the copper amount leached from the lateral surfaces, and the mobility of copper was very restricted in soil. The copper contents of soil within 10 cm from the treated deck posts installed in the parks showed to be less than 500 mg/kg, which are the limit values of the 2nd region set up by enforcement regulation of soil environment conservation act. The distribution ranges of copper in soil from the treated wood set up in the field test sites seemed to be much wider than those from deck posts, which may explained by the fact that the retentions of the treated samples used in the field test sites were much higher than those of the deck posts.