• Title, Summary, Keyword: column leaching

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Leaching Characteristics of Foundry Sands When Used as Reactive Media in Permeable Reactive Barriers (반응벽체에 쓰인 주물사의 용출특성에 관한 연구)

  • ;Benson, Craig H
    • Journal of the Korean Geotechnical Society
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    • v.18 no.5
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    • pp.179-193
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    • 2002
  • Waste foundry sands were tested to determine their leaching characteristics when used as reactive media in permeable reactive barriers (PRBs). Water leach tests and column leach tests were performed on twelve foundry sands and three reference materials such as Peerless iron, a local fill material, and torpedo sand. The latter three materials were tested to compare concentrations of heavy metals and anions found in other materials commonly placed below the groundwater table with those from the foundry sands. Results of water leach tests md total elemental analyses showed that all of the laundry sands are Category 2 materials per Section NR 538 of the Wisconsin Administrator Code. However, tests on Peerless iron, torpedo sand, and a typical fill material indicate that these materials, which are commonly placed below the groundwater table, also are Category 2 materials. Thus, using foundry sand as a PR3 medium should pose no greater risk than that imposed using conventional construction materials.

A Study on the Utilization of Organic Mixed Soil as Earthwork Materials (유기질 혼합토의 토공재로서의 활용에 관한 연구)

  • Park, Heung-Gyu;Koo, Je-Min
    • Journal of the Korean Geoenvironmental Society
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    • v.3 no.4
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    • pp.29-35
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    • 2002
  • In order to establish the applicability of organic soil as Earthwork Materials, this research conducts a battery of laboratory tests using two kinds of test materials. The test material A, a mixture of sand and organic soil, and the test material B, a mixture of granite soil and organic soil varying the proportion of organic soil through 5%, 10%, 20%, 30%, 40%, and 50% are used. Continuous column leaching tests of the test materials A and B indicate that their COD value is substantially smaller than that of pure organic soil, the COD value of the early leached water slightly exceeds the standard level for leached water. The COD value after 4 hours of leaching becomes very small. The mixed soil of sand and organic soil is considered usable as embankment materials when the proportion of organic soil is up to 40% with the corresponding concentration ratio of organic contents is less than 11.3%. Similarly, the mixed soil of granite soil and organic soil is considered usable as earthwork materials when the proportion of organic soil is less than 30% with the corresponding concentration ratio of organic contents is less than 16.4%.

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In-situ Stabilization of Heavy Metal Contaminated Farmland Soils Near Abandoned Mine, using Various Stabilizing Agents: Column Test Study (폐광산 주변 중금속 오염 농경지 토양복원을 위한 다양한 첨가제의 안정화 효율 비교: 컬럼시험연구)

  • Lee, Sang-Hoon;Cho, Jung-Hoon
    • Journal of Soil and Groundwater Environment
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    • v.14 no.4
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    • pp.45-53
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    • 2009
  • This study concerned remediation of heavy metal contaminated farmland soils near abandoned mine, using stabilization method, with particular emphasis on the remediating the soils contaminated with multi-elements. In this study, stabilizing heavy metals based on 'In-situ chemical fixation' has been applied to the soil collected from an abandoned mine in Korea, using column test, with various stabilizing agents, including $FeSO_4$, $KMnO_4$, sludge (collected from coal mine drainage treatment pond), zero-valent iron (ZVI), zeolite and $CaCO_3$. Sixty five-days operation of the flow-through columns yield $FeSO_4\;+\;KMnO_4$ and zeolite are efficient on reducing As leaching from the soil. ZVI and sludge are reducing the leaching of Cu. Although $FeSO_4\;+\;KMnO_4$ seem to be efficient for most heavy metals, high pH in the initial stage of test enabled high leaching of the heavy metals, whereas fixation of the heavy metals maintain throughout the rest of the test period, with increasing pH up to around 6. Addition of some alkaline agent may inhibit the low pH during the application. The column test was also run as two set: one set incubated with deionized water for 72 hours prior to starting the test, and the other without incubation. The incubated set demonstrated better stabilizing efficiency, indicating the potential optimized operation method.

Lime (CaO) and Limestone ($CaCO_3$) Treatment as the Stabilization Process for Contaminated Farmland Soil around Abandoned Mine, Korea (폐광산 주변 중금속 오염 농경지 토양 복원을 위한 석회(CaO)와 석회암($CaCO_3$)의 안정화 효율 규명)

  • Lee, Min-Hee;Lee, Ye-Sun;Yang, Min-Jun;Kim, Jong-Seung;Wang, Soo-Kyn
    • Economic and Environmental Geology
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    • v.41 no.2
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    • pp.201-210
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    • 2008
  • The mixing treatment process using lime (CaO) and limestone ($CaCO_3$) as the immobilization amendments was applied for heavy metal contaminated filmland soils around Goro abandoned Zn-mine, Korea in the batch and pilot scale continuous column experiments. For the batch experiments, with the addition of 0.5 wt.% commercialized lime or limestone, leaching concentrations of As, Cd, Pb, and Zn from the contaminated filmland soil decreased by 70, 77, 94, and 95 %, respectively, compared to those without amendments. For the continuous pilot scale column experiments, the acryl column (30 cm in length and 20 cm in diameter) was designed and granulated lime and limestone were used. From the results of column experiments, with only 2 wt.% of granulated lime, As, Cd, and Zn leaching concentrations decreased by 63%, 97%, and 98%, respectively. With 2 wt.% of granulated limestone, As leaching concentration reduced from 135.6 to 30.2 ${\mu}g/L$ within 5 months and maintained mostly below 10 ${\mu}g/L$, representing that more than 46% diminution of leaching concentration compared to that without the amendment mixing. For Cd and Zn, their leaching concentrations with only 2 wt.% of limestone mixing decreased by 97%, respectively compared to that without amendment mixing, suggesting that the capability of limestone to immobilize heavy metals in the filmland soil was outstanding and similar to that of lime. From the column experiments, it was investigated that if the efficiency of limestone to immobilize heavy metals from the soil was similar to that of lime, the limestone could be more available to immobilize heavy metals from the soil than lime because of low pH increase and thus less harmful side effect.

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

  • Chun, Si-Bum;Hyun, Ik-Hyun;Lee, Min-Gyu;Kam, Sang-Kyu
    • Journal of Environmental Science International
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    • v.27 no.7
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    • pp.561-575
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    • 2018
  • Agricultural soils around springwaters heavily affected by pesticide run-off and around wells considering the regional characteristics were collected at 24 stations in Jeju Island, and the physicochemical properties and adsorption and leaching characteristics of four nonionic pesticides (diazinon, fenitrothion, alachlor, and metalaxyl) were investigated. The values of the major soil factors affecting the adsorption and leaching of pesticides, namely, soil pH($H_2O$), organic matter content, and cation exchange capacity (CEC), were in the range of 4.64 ~ 8.30, 0.9 ~ 13.1% and 12.7 ~ 31.7 meq/100 g, respectively. The Freundlich constant, $K_F$ value, which gives a measure of the adsorption capacity, decreased in the order of fenitrothion > diazinon > alachlor > metalaxyl, which was identical to their lower water solubility. Among the collected soils, the $K_F$ value was very highly correlated with organic matter content ($r^2=0.800{\sim}0.876$) and CEC ($r^2=0.715{\sim}0.825$) and showed a high correlation with clay content ($r^2=0.473{\sim}0.575$) and soil pH($H_2O$) ($r^2=0.401{\sim}0.452$). The leaching of pesticides in the soil column showed a reverse relationhip with their adsorption in soils, i.e., the pesticides leached more quickly for the soils with lower values of organic matter content and CEC among the soils and for the pesticides with higher water solubility.

The Effect of Rootzone Mix and Compaction on Nitrogen Leaching in Kentucky bluegrass (토양의 종류와 답압이 켄터키블루그래스 토양층에서 질소용탈에 미치는 영향)

  • Lee, Sang-Kook;Frank, Kevin W.;Crum, James R.
    • Asian Journal of Turfgrass Science
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    • v.24 no.1
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    • pp.45-49
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    • 2010
  • Research on nitrate-nitrogen ($NO_3-N$) leaching in turfgrass indicates that in most cases leaching poses minimal risk to the environment. Although there have been many studies investigating $NO_3-N$ leaching, there has been little research to investigate the effect of compaction level and rootzone mix on nitrogen (N) leaching. The research objective is to determine the effect of compaction level and rootzone mix on nitrogen leaching. The four rootzone mixes are 76.0:24.0, 80.8:19.2, 87.0:13.0 and 93.7:6.3 % (sand:soil). The four levels of compaction energies are 1.6, 3.0, 6.1, and 9.1 J $cm^{-2}$. Nitrogen was applied using urea at a rate of 147 kg $ha^{-1}$ split among three applications. Rootzone was packed into a polyvinylchloride pipe with a perforated bottom to facilitate drainage. Rootzone depth was 30 cm over a 5 cm gravel layer. Each column was sodded with Poa pratensis L. Hoagland solution designed for coolseason grasses, minus N, was used to ensure adequate nutrition in the rootzone. Turf grass quality and clipping yield were recorded from each tube at two-week intervals. The clippings were oven-dried at a temperature of $67^{\circ}C$ for 24 h and weighed. At the end of the study, root dry weight was determined by washing and oven-drying samples at $67^{\circ}C$ for 24 h. Leachate solution was collected weekly for analysis. More than 6.1 J $cm^{-2}$ of compaction energy increased possibilities of surface runoff. The compaction energy between 3.0 and 6.1 J $cm^{-2}$ produced more clipping dry weight and less N leaching than 9.1 J $cm^{-2}$.

Pollutant Monitoring of Abandoned Mines using the Leaching Test with Soils and Tailings (토양 및 광미의 용출실험을 이용한 폐광산오염수준의 모니터링)

  • Kang, Mee-A;Kim, Kwang-Tae
    • The Journal of Engineering Geology
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    • v.17 no.3
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    • pp.419-424
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    • 2007
  • The contents were investigated by the monitoring survey from the soils and tailings caused by numerous abandoned mines in Korea. Cause heavy metals due to abandoned metal mines are raising significant environmental problems. But it is an important key such as a leaching and a transfer mechanism to evaluate contamination levels caused by abandoned mines. In this study the column test was carried in order to calculate a leaching level from soils and tailings. It was demonstrated that the leaching of Pb, Cd and Mn was expressed with similar behaviors and that of As and Cu was expressed with similar behaviors. For Zn, the leaching behavior was shown a serious leaching level with 40 mg/kg during the 45days. This was explained by Zn high contents of soils Zn in a natural world and ORP conditions where the leaching of Zn was occurred easily. Hence it was necessary that the survey of ORP was a key as well as total contents for the management of abandoned metal mines. We could estimate the chemical forms of heavy metals using the physical index such as ORP and pH and reduce the risk from heavy metals caused by abandoned metal mines.

A Leaching Characteristics on Lime Stabilization of Heavy Metal Contaminated Soil in a Waste Mine Area (폐 광산 지역 중금속 오염 토양의 석회안정화 적용 시 용출특성)

  • Oa, Seong-Wook
    • Journal of Korean Society on Water Environment
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    • v.27 no.6
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    • pp.862-867
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    • 2011
  • Pozzolanic-based stabilization/solidification (S/S) is an effective and economic remediation technology to immobilize heavy metals in contaminated soils. In this study, quick lime (CaO) was used to immobilize cadmium and zinc present in waste mine contaminated clayey sand soils. Addition of 5% quicklime to the contaminated soils effectively reduced heavy metal leachability after 2 bed volume operation below the drinking water regulatory limits. Lime addition was revealed to increase the immobilization for all heavy metals in tested pH ranges, so it could be an optimal choice for short-term remediation of heavy metal contaminated soil. The mass balances for these column tests show metal reduction of 92% for Cd and 87% for Zn of total resolved mass in case of 5% lime application.

Surface Electrochemical Study on the Fixation Properties of New Water-borne Preservatives in Red Pine (새로운 수용성(水溶性) 방부방충제(防腐防蟲劑)의 재중(材中) 정착성(定着性)에 관한 계면전기화학적(界面電氣化學的) 특성(特性))

  • Kim, Yeong-Suk
    • Journal of the Korean Wood Science and Technology
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    • v.24 no.4
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    • pp.93-99
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    • 1996
  • In order to investigate the extent of fixation of new water-borne preservatives in blocks of pinus densiflora sapwoods the streaming potential through the column with preservative treated wood was measured at various conditions. The rates of leachability of ingredients in the treated wood were estimated by the measurement of electric conductivity of the solution with the leached components. The solution was also analyzed by Atomic absorption spectrophotometer (AA). As a results, the experimental data indicated that the fixation of CCB, CCFZ and ACQ in wood were relatively unstable. The fixation rates of CCB, CCFZ were improved by increasing heat and drying time. The amounts of the leached ingredients were apparently higher in CCB and CCFZ than in CCA, while the rate of leaching of ACQ was not changed at various drying temperature.

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Nanocomposite SiEA-KNiFe sorbent - Complete solution from synthesis through radiocesium sorption to vitrification using the sol-gel method

  • Chmielewska, Dagmara;Siwek, Malgorzata;Wawszczak, Danuta;Henczka, Marek;Sartowska, Bozena;Starosta, Wojciech;Dudek, Jakub
    • Journal of Industrial and Engineering Chemistry
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    • v.67
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    • pp.407-416
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    • 2018
  • This study presents a novel complete solution starting with a synthesis of silica modified with potassium-nickel hexacyanoferrate and ethanolamine (SiEA-KNiFe) sorbent through radiocesium sorption in different process configurations and moving on to the vitrification of the spent sorbent, using the sol-gel method. The experimental data for deionized water solution, as well as seawater solution, correlates strongly with the Langmuir isotherm model. Moreover, the study also presents a method for spent sorbent solidification in the glass matrix. The cesium leaching test confirmed that spent sorbent can be stably bound in the glass matrix after radionuclide removal.