• 제목/요약/키워드: 복토재

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Use of Sewage Sludge Ash for Construction Material (건설재로서 하수슬러지 소각재의 활용)

  • Lee, Cheo-Keun;Ahn, Kwang-Kuk;Heo, Yol
    • Journal of the Korean GEO-environmental Society
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    • v.4 no.4
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    • pp.25-34
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    • 2003
  • This paper is focused on an experimental study in order to investigate the utilization of sewage sludge ash as the cover and liner materials for the waste disposal landfill or as construction materials. A series of tests were performed to evaluate the basic properties, compaction, compressive strength, consolidation, permeability, and CBR of sewage ash. Specially, clay bricks were made as increasing replacement ratio of sewage ash (such as 5, 10, 15, 20, 25, 30%). And tests were fulfilled for its quality. Bentonite and lime were used as the additives to improve permeability properties of sewage sludge ash. As a result of tests, it was shown that the permeability coefficient decreases as increasing bentonite content and the percentage of bentonite was roughly needed 20% to keep the permeability coefficient below $1{\times}10^{-7}cm/sec$. The results of unconfined compression tests show that sewage ash meets the criteria of the unconfined compression strength for cover material. It was shown that the compressive strength decreases as increasing the replacement ratio of sewage sludge ash and the maximum replacement ratio of sewage sludge ash to satisfy the quality standards of the third degree bricks was about 15%.

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Evaluation on Feasibility of Industrial By-products for Development of Mono-Layer Landfill Cover System (산업부산물을 이용한 단층형 매립지 복토시스템 개발을 위한 적용 타당성 평가)

  • Kim, Soon-Oh;Kim, Pil-Joo;Yu, Chan
    • Journal of Korean Society of Environmental Engineers
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    • v.30 no.11
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    • pp.1075-1086
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    • 2008
  • In order to investigate the applicability and suitability of the industrial by-products to apply mono-layer cover system for non-sanitary landfill sites, 6 different industrial by-products, such as construction waste, bottom ash, gypsum, blast furnace and steel manufacture slags, and stone powder sludge, were evaluated. Various physicochemical and hydrodynamic properties of the industrial byproducts were investigated. The environmental safety was monitored using batch and long-term leaching tests as well. In addition, the flexibility of plants was observed by cultivating them in the industrial by-products. The results for physicochemical properties indicate that most of the materials considered appeared to be suitable for landfill cover. Particularly, the concentration levels of hazardous elements regulated by the Korean Law for Waste Management did not exceed the regulatory limits in all target materials. In addition, the concentrations of regulated elements for the Korean Soil Conservation Law were examined below the regulatory limits in most of materials considered, except for the stone powder sludge. The results of batch and long-term experiments showed bottom ash and construction waste were the most suitable materials for landfill cover among the industrial by-products considered. The results of plant studies indicate that the bottom ash among industrial by-products considered was most effective in developing vegetation on landfill site, showing fast germination and large growth index. At the final covering system made of mixture of soil and bottom ash, the optimum application rate of farmyard manure was observed to be 40-50 Mg/ha.

Contamination and Geochemical Speciation of Heavy Metals in Middle Cover Soils and Clay Liner from the Kumheung Landfill, Gongju City (공주 금흥매립지의 중간복토재 및 차수재(논토양)의 중금속 오염과 존재형태 연구)

  • 이평구;박성원;염승준
    • Economic and Environmental Geology
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    • v.34 no.3
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    • pp.283-299
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    • 2001
  • The middle cover soils and clay liners collected from the Kumheung landfill in Gongiu City were analysed for As, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sr, Ti and Zn concentrations using 0.] N HCl digestion and total/sequential extraction experiments followed by ICP-AES determination. The uncontaminated soil and sediment samples were also analyzed for the comparison. The results of sequential extraction showed that Cu was dominant in the oxidizable fraction, and As, Ni, Sr, Ba, and Mn were in the exchangeable fraction. Zinc and Mn occurred mostly in association with reducible, residual and carbonate fractions. Most of Cd and Pb were bound to the reducible and oxidizable fractions. The main carrier of Co, Cr, Fe and 11 was the residual fraction and another important carrier was the reducible fraction. The percentage of the metals of organically-bound form in the middle cover soils and clay liner was in the order of Cu(48%) > Ti(42%) > Pb(27%) > As(25%) > Cd(20%). As deduced from sequential extraction analysis, potential order of metal mobility in the middle cover soils and clay liner from the landfill was proposed: Cd > Sr > As > Ni > Mn > Ba > Cu > Pb > Zn » Co > 11 > Fe > Cr. Based on the 'geoaccumulation index' and the 'enrichment factor' normalized to A], the level of contamination of Cu, Ni and C1' was significant in the samples from Kumheung landfill and surrounding farmland. Their enrichments were attributed partly to anthropogenic pollutions.

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Transfer of Arsenic from Paddy Soils to Rice Plant under Different Cover Soil Thickness in Soil Amendments in Abandoned Coal Mine (폐탄광지역 비소오염 농경지(논) 개량 시 복토두께에 따른 비소의 벼 전이 및 토양용액 특성)

  • Koh, Il-Ha;Kwon, Yo Seb;Jeong, Mun-Ho;Ko, Ju In;Bak, Gwan-In;Ji, Won Hyun
    • Economic and Environmental Geology
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    • v.54 no.4
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    • pp.483-494
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    • 2021
  • This study was carried out to investigate the feasibility of reducing clean cover soil using a flooded column test in arsenic-contaminated farmland reclamation of abandoned coal mine area that shows generally low or about worrisome level (25 mg/kg) of Korea soil environment conservation act unlike abandoned metal mine. During the monitoring period of soil solution for 4 months, chemical properties (pH, EC, ORP, Fe, Mn, Ca, and As) in each layer (clean soil cover and contaminated/stabilized soil) showed different variation. This result revealed that soil solution in stabilized or contaminated soil rarely affected that in cover soil. Whether stabilized or not, arsenic concentrations in the rice roots grown in the soil covers with the thickness of 40 cm decreased by 98% in compared with the that grown in the control soil. In case of the soil covers with 20 cm thickness on stabilized soil, it decreased by 80% and this was 22 percentage point higher than when the soil of lower layer was not stabilized. Thus, reducing clean cover soil could be possible in contaminated farmland soil reclamation if appropriate stabilization of contaminated soil is carried.