• Title, Summary, Keyword: column leaching

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Leaching Behavior of the Residues of Carbofuran, Bentazon, and TCAB in Soil (Carbofuran, Bentazon 및 TCAB 잔류물의 토양중 용탈)

  • Lee, Jae-Koo;Oh, Kyeong-Seok
    • Korean Journal of Environmental Agriculture
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    • v.12 no.1
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    • pp.9-17
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    • 1993
  • The leaching behavior of $^{14}C-carbofuran$, $^{14}C-bentazon$, and $^{14}C-3,3,4,4'-tetrachloroazobenzene(TCAB)$ in the forms of freshly treated, 3-month-aged, and 6-month-aged residues, respectively, was investigated in a loamy soil column system. The degradation and mobility of pesticides in soil and the possibility of the contamination of groundwater were followed by this approach: The ambient temperature of $15{\pm}2^{\circ}C$, irrigation by the constant-head method on soil columns, and leaching with 1332 ml of simulated precipitation during 90 days. While the fresh residues of $^{14}C-carbofuran$ and $^{14}C-bentazon$ were very mobile, the aged ones were remarkably reduced in their mobility. Fresh and aged residues of $^{14}C-TCAB$ were very immobile, instead. 3-Keto carbofuran phenol(2,3-dihydro-2,2-dimethyl-3-oxo-7-benzofuranol) was the major degradation product present in the leachate from the soil column containing freshly treated $^{14}C-carbofuran$, while no metabolites could be detected in the leachates from the columns containing $^{14}C-bentazon$ or $^{14}C-TCAB$.

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Cation Leaching from Soils Percolated with Simulated Sulfuric Acid Rainn (人工酸性 빗물에 의한 여러 土壤으로부터의 이온 洗脫)

  • Rhyu, Tae-Cheol;Joon-Ho Kim
    • The Korean Journal of Ecology
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    • v.16 no.2
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    • pp.169-180
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    • 1993
  • Soils of four combinations, sand with high content of organic matter(SL), sand with low content of OM(SS), siltyl loam with high content of OM(LL) and silty loam with low content OM (LS), were filled on column and then percolated with simulated sulfuric acid rain with pH 5.6, 4.0, 3.5, 3.0 and 2.5. From soil leachates, pH and concentrations of basic cations and Al were determined. Cation concentrations in the leachates increased as pH of the rain decreased. The orders of buffering capacity of soil, leachability of cation from soil, leaching sensitivity of ion andbase saturation sensitivity of soil to acidity of the rain water were SS$\leq$K <$\leq$LL

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Adsorption and Leaching Characteristics of Ionic Pesticides in the Soils of Jeju Island, Korea (제주도 토양 중 이온계 농약의 흡착 및 용탈 특성)

  • Chun, Si-Bum;Hyun, Ik-Hyun;Kam, Sang-Kyu
    • Journal of Environmental Science International
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    • v.28 no.8
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    • pp.689-700
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    • 2019
  • The adsorption and leaching characteristics of five ionic pesticides including four acidic pesticides (2,4-D, dicamba, MCPA, and MCPP) and one amphoteric pesticide (imazaquin) in agricultural soils were investigated. Soils around spring waters that were heavily affected by pesticide run-off and soils around wells considering the regional characteristics in Jeju Island were collected at 24 stations. The Freundlich constant, $K_F$ value, which is a measure of the adsorption capacity, decreased in the order of 2,4-D > MCPA > MCPP > dicamba > imazaquin. The adsorption capacity of these ionic pesticides decreased with increasing pH owing to the effects of ionization of pesticides and different ionizable functional groups of soils. The leaching of ionic pesticides in the soil column showed a reverse relationship with their adsorption in soils, namely, the ionic pesticides were leached more quickly for the pesticides with lower adsorption capacity. The groundwater contamination potential of the ionic pesticides was evaluated in the order of imazaquin > MCPA > MCPP > dicamba > 2.4-D according to the groundwater ubiquity score based on soil Koc and the half-life of the pesticide.

하수슬러지의 토양개량재 적용시 유기인계 농약의 흡착능력에 관한 연구

  • 임은진;이재영
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • pp.125-130
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    • 2004
  • This study has been assessed the influence of applying sewage sludge to soil amendments on the sorption properties, and leaching potential of three commonly used organophosphorus pesticides, Diazinon, Fenitrothion, and Chlorpyrifos. A sandy soil with a low content of organic carbon was treated with sewage sludge with a ratio sandy soil : sludge ratio of 30:1. The sorption was determined with the batch equilibrium technique. The sorption isotherms could be described by Freundlich equation. The Freundlich constant, K value which measures sorption capacity, were 3.97, 9.94, 22.48 for Diazinon, Fenitrothion, Chlorpyrifos in non-amended soil. But in amended soil, K value was 12.58, 28.47, and 61.21 for Diazinon, Fenitrothion, and Chlorpyrifos. The overall effect of sewage sludge addition to soil was to increase pesticides adsorption, due to the high sorption capacity of the organic matter. The effect of sludge on tile leaching of pesticides in the soil was studied using packed soil columns. Total recoveries of pesticides in soil and leachate with leaching in soil column, were in the range of about 73~84%, was reduced with the passage of time. Diazinon moved more rapidly than Chlorpyrifos in the unamended soil due to greater sorption and lower water solubility of Chlorpyrifos. Total amounts of pesticides leached from the sewage sludge amended soils were significantly reduced when compared with unamended soils. This reduction may be mainly due to and increase in sorption in amended soils, as a consequence of the increase in the organic matter content.

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Effect of soil Venting on Dissolution Potential of Gasoline Components in Contaminated Soil: Experimental Observation (Soil Venting이 오염토양중 가솔린 성분의 용출성에 미치는 영향: 1. 실험적 고찰)

  • 염익태;이상현;안규홍
    • Journal of Korea Soil Environment Society
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    • v.3 no.2
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    • pp.53-60
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    • 1998
  • The influence of venting on the leaching characteristics of pure gasoline and gasoline contaminated soil was studied. The change of leaching characteristics by venting of contaminated soil column could be characterized by two distinct trends : 1) the leaching concentration in TPH-GRO rapidly decreased with evaporation until the evaporation loss became 75% of the original volume. Afterwards, it gradually decreased. 2) the leaching concentrations of individual components showed initial increase followed by gradual decrease. In general, the relative increase of leaching concentration and the venting time to reach the maximum increased with the molecular weight of the components. It should be noted that the decrease of gasoline concentration in the vented air occurs faster than that in the leaching solution. This indicates that, after removing most of the gasoline by evaporation, the focus of the risk assessment for the residual contaminants should be on the groundwater contamination rather than air pollution.

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Urea Transformation and Nitrogen Loss in Waterlogged Soil Column

  • Seol, Su-Il;Lee, Sang-Mo;Han, Gwang-Hyun;Choi, Woo-Jung;Yoo, Sun-Ho
    • Journal of Applied Biological Chemistry
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    • v.43 no.2
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    • pp.86-93
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    • 2000
  • An experiment was conducted to obtain the quantitative data on the transformation and loss of applied urea-N in waterlogged soil columns. The soil columns were pre-incubated for 35 days to develop oxidized and reduced soil conditions prior to urea application. After urea application at the rate of $150kg\;N\;ha^{-1}$(29.5 mg N), the amounts of nitrogen which were volatilized, leached, and remained in soil column were measured during 38 days of incubation period. On 2 and 4 days of incubation, 54.1%(15.9 mg N) and 98.4%(29.0mg N) of the applied urea was hydrolyzed, respectively. Most of the applied urea was completely hydrolyzed within 6 days. After urea application, the rates of ammonia volatilization were increased with the floodwater pH when the floodwater pH were higher than 7.0. The maximum rate of ammonia volatilization was $0.3mg\;d^{-1}$ when pH of the floodwater showed maximum value of 7.6. The total amount of volatilized nitrogen was 6.1% (1.8mg N) of the applied urea-N. A 63.2 % (18.6mg N) of the applied urea was remained in soil as $NH_4{^+}-N$ and 28.0% (8.2mg N) of the applied urea was leached as $NH_4{^+}-N$ at the end of the incubation. Amount of $NO_3{^-}-N$ in soil was smaller than 2.0 mg throughout the incubation period. The total amount of $NO_3{^-}-N$ leached was very small, which value was 1.8 mg. It suggested that nitrification process was not significant in waterlogged soil column of this study due to high infiltration rate of urea solution applied to the soil column. Therefore only small amount of $NO_3{^-}-N$ was lost by denitrification and leaching process.

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Effects of Paper Mill Sludge in submerged Soil (제지(製紙)슬러지의 답토양(畓土壤) 시용효과(施用效果))

  • Choi, Jong Woo;Jo, Jeong Rye;Lee, Kyu Seung;Kim, Moon Kyu
    • Korean Journal of Agricultural Science
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    • v.19 no.2
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    • pp.187-193
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    • 1992
  • The effects of continuous restoration of sludge into the reclamating paddy soil and leaching test of sludge components by soil column were investigated. 1. The contents of nitrogen, phosphorus, potassium, C.E.C. and organic matter(O.M.) were increased in/on the paddy soil treated with paper mill sludge than non-treated. 2. Humic layer depth recognized by color showed the non-treated(10 cm), second year(15 cm) and third year(20 cm), respectively. 3. The effects of sludge treatment showed in the contents of O.M. such as non-treatment(0.9 %) < second year(1.39 %) < third year(1.75 %) in 10 cm depth. 4. All components in soil tested with column were increased by holding capacity of sludge, and the contamination effects of soil and ground water were not found by leaching test.

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Changes of Performance of Soil-Cement Barrier due to Migration of Acids (산 이동에 따른 심층혼합기둥체 차수벽의 성능변화)

  • 정문경;천찬란;이주형;김강석
    • Proceedings of the Korean Geotechical Society Conference
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    • pp.189-196
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    • 2003
  • Soil-cement column is often used as a contaminant barrier. This study presents the results of experimental study performed to investigate the changes of properties of soil-cement column under the attack of acids. Sulfuric nitric, and ascetic acid were used as contaminants. Specimen were made of clayey and sandy soils with addition of cement and water Permeability of soil-cement decreased with time during permeability test. When significant amount of acid percolated the specimen, permeability increased and compressive strength decreased due to the dissolution and leaching of cement and its chemical reaction compounds. Sulfuric and nitric acid were more effective than ascetic acid in deteriorating soil-cement column. Amount of acid required to lower the pH of soil cement below 12 was calculated from the results of permeability tests. This leads to a conclusion that, under the conditions employed in this study, the chemical stability of soil-cement column could be maintained against acid attack for longer than generally accepted lifetime of contaminant barriers.

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The Assessment of Water Quality Contamination Following the Utilization of Coal Ash as Fill Material (성토재로서 석탄회 사용에 따른 수질오염도 평가)

  • 김학삼;조삼덕
    • Geotechnical Engineering
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    • v.11 no.3
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    • pp.5-16
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    • 1995
  • In this paper, two leaching tests(batch test & column test) were carried out to estimate the detrimental effects of coal ash leachates. The variation of constituents and concentration of coal ash leachate with the lapse of leachins time was analysed through the column tests. From the test results, it was found coal tach can be classified as a general waste, and all other items except pH of coal ash leachate are satisfied the concentration requirements for the drinking water. It was also found the concentration of coal ash rapidly decrease with the lapse of the leaching time and become the insignificant value after an elapsed time.

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Impact of Residual Hydrofluoric Acid on Leaching of Minerals and Arsenic from Different Types of Geological Media (잔류 불산에 의한 모델 지질토양시료의 광물 용해 및 비소 용출 특성)

  • Jeon, Pilyong;Moon, Hee Sun;Shin, Doyun;Hyun, Sung Pil
    • Journal of Soil and Groundwater Environment
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    • v.23 no.2
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    • pp.23-29
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    • 2018
  • This study explored secondary effects of the residual hydrofluoric acid (HF) after a hypothetical acid spill accident by investigating the long-term dissolution of minerals and leaching of pre-existing arsenic (As) from two soil samples (i.e., KBS and KBM) through batch and column experiments. An increase in the HF concentration in both soil samples resulted in a dramatic increase in the release of major cations, especially Si. However, the amounts of mineral dissolved were dependent on the soil type and mineral characteristics. Compared to the KBM soil, relatively more Ca, Mg and Si were dissolved from the KBS soil. The column experiment showed that the long-term dissolution rates of the minerals are closely associated with the acid buffering capacity of the two soils. The KBM soil had relatively higher effluent pH values compared to the KBS soil. Also, more As was leached from the KBM soil, with a more amorphous hydrous oxide-bound As fraction. These results suggest that the potential of heavy metal leaching by the residual acid after an acid spill will be influenced by heavy metal speciation and mineral structure in the affected soil.