Kaolinitin kıvam limitleri üzerine inorganik tuz çözeltilerinin etkileri

Öz

Bu çalışma, farklı konsantrasyonlardaki inorganik tuzların (KCl, BaCl₂, MgCl₂, KNO₃, Na₂SO₄ ve MgSO₄) bariyer sistemlerde geçirimsizlik alt tabaka dolgu malzemesi olarak kullanılan kaolinitin geoteknik özellikleri (Atterberg Limitleri) üzerine etkileri ortaya koymaktadır. Distile su veya çeşme suyu kullanımı, depo sahası koşullarını temsil edici olmadığından, dolgu malzemeleri üzerine sızıntı suyu etkilerini araştırmak için tuz çözeltileri kullanılmıştır. Ayrıca, kaolinit malzemesinin minerolojik karakterizasyonu incelenmiştir. Killi zemin numunelerinin, Birleşik Zemin Sınıflandırma Sistemi’ne göre Atterberg Limtleri; likit limit (LL) ve plastik limit (PL) değerleri belirlenmiş ve minerolojik çalışmalar için XRD, BET ve FT-IR analizleri gerçekleştirilmiştir. Elde edilen sonuçlar, tüm tuz çözeltilerinin kaolinin kıvam limitleri üzerinde önemli bir etkisi olduğunu göstermiştir. Kimyasal konsantrasyon artışı, kaolinitin likit limit değerlerini düşürürken plastik limit değerlerini arttırmıştır. 2 ve 3 değerlikli katyonların kaolin üzerine etkileri, tek değerlikli katyonlara göre açıkça görülmüştür. Sonuç olarak, kaolinit malzemesi hidrolik iletkenliği artar ve şişme eğilimi azalırken, DDL tabakası incelme ve kaolinit partikülleri floküle olma eğiliminde iken, kimyasal çözeltiler yüksek plastisiteye sahip kaolinit malzemesinin likit limit değerlerlerini düşürmektedir.

Anahtar Kelimeler

• İnorganik tuzlar,kıvam limitleri,kaolinit,düzenli depolama,bariyer sistemler

Effect of inorganic salt solutions on consistency limits of kaolinite

Öz

This study presents the effect of different inorganic salt solutions (KCl, BaCl₂, MgCl₂, KNO₃, Na₂SO₄ and MgSO₄) at different concentrations on geotechnical properties (Atterberg Limits) of kaolinite material which can be used as impermeable bottom liner in barrier systems. Since the use of distilled water or tap water is far from being representative of the in-situ conditions in landfills, salt solutions were used to investigate the leachate effect on liner materials. Additionally, the mineralogical characterization of kaolinite was studied.  Atterberg limits, specifically the liquid limit (LL) and plastic limit (PL) that were used for classifying the clayey soil samples according to the Unified Soil Classification System were determined whereas mineralogical studies performed included XRD, BET and FT-IR analyses. Results indicated that all salt solutions have a considerable effect on the consistency limits of kaolinite. The liquid limit values of kaolinite decreased with increasing chemical concentration whereas plastic limit values increased. It is observed that the effects of the divalent and trivalent cations on kaolinite were more apparent than those of monovalent cations. As a result chemical solutions decrease liquid limit values of high plasticity kaolinite materials,  tend to reduce the thickness of the DDL and flocculate the kaolinite particles, resulting in reduction of swelling and increasing of hydraulic conductivity.

Anahtar Kelimeler

• Inorganic salts,consistency limits,kaolinite,landfilling,barrier systems

Kaynakça

1. Renou, S., Givaudan, J.G., Poulain, S., Dirassouyan, F., ve Moulin P., Landfill leachate treatment: Review and opportunity, Journal of Hazardous Materials, 150, 468-493, (2008).
2. El-Fadel, M., Findikakis, A.N. ve Leckie, J.O., Environmental impacts of solid waste landfilling, Journal of Environmental Management, 50, 1, 1-25, (1997).
3. Murray, E.J., Rix, D.W. ve Humphrey R.D., Clay linings to landfill sites, Quarterly Journal of Engineering Geology and Hydrogeology, 25, 371–376, (1992).
4. Seymour, K.J., Landfill Lining for Leachate Containment, Water and Environmental Management, 6, 389–396, (1992).
5. Thornton, S.F., Lerner, D.N. ve Tellam, J.H., Attenuation of landfill leachate by clay liner materials in laboratory columns: 2. Behaviour of inorganic contaminants, Waste Management &. Research, 19, 70–88, (2001).
6. Schmitz, R.M., Schroeder, C., ve Charlier, R., Chemo-mechanical interactions in clay: A correlation between clay mineralogy and atterberg limits, Applied Clay Science, 26, 351-358, (2004).
7. Jo, H.Y., Benson, C.H., Shackelford, C.D., Lee, J.M. ve Edil, T.B., Long-term hydraulic conductivity of a geosynthetic clay liner permeated with ınorganic salt solutions, Journal of Geotechnical and Geoenvironmental Engineering., 131, 405-417, (2005).
8. Park, J., Vipulanandan, C., Kim, J.W. ve Oh, M.H., Effects of surfactants and electrolyte solutions on the properties of soil. Environmental Geology, 49, 977 – 989, (2006).

9. Abdi, M.R., Parsapajouh, A. ve Arjomand, M.A., Effects of random fiber inclusion on consolidation, hydraulic conductivity, swelling, shrinkage limit and desiccation cracking of clays, International Journal of Civil Engineering, 6, 4, (2008).
10. Yılmaz, G., Yetimoglu, T. ve Arasan, S., Hydraulic conductivity of compacted clay liners permeated with inorganic salt solutions, Waste Management &. Research, 26, 5, 464-473, (2008).
11. Shariatmadari, N., Salami, M. ve Fard, M.K., Effect of inorganic salt solutions on some geotechnical properties of soil-bentonite mixtures as barriers, International Journal of Civil Engineering, 9, 2, (2011).
12. Alawaji, H.A., Swell and compressibility characteristics of sand-bentonite mixtures ınundated with liquids, Applied Clay Science, 15, 411-430, (1999).
13. Met, I., Akgun, H. ve Turkmenoglu, A.G., Environmental geological and geotechnical ınvestigations related to the potential use of ankara clay as a compacted landfill liner material, Environmental Geology, 47, 225-236, (2005).
14. ASTM D 4318-00, “Standard test methods for liquid limit, plastic limit, and plasticity index of soils”, Annual Book of ASTM Standards, pp. 582-595, American Society For Testing and Materials, West Conshohocken, PA, 04.08, (2003).
15. ASTM D421, “Practice for dry preparation of soil samples for particle-size analysis and determination of soil constants”, ASTM, West Conshohocken, Pa., (1985).
16. ASTM D422, “Test method of particle-size analysis of soils”, ASTM, West Conshohocken, Pa., (1963).
17. Rao, S.N. ve Mathew, P.K., Effects of exchangeable cations on hydraulic Conductivity of a marine clay. Clay Minerals, 43, 4, 433-437, (1995).
18. Arasan, S., Effect of chemicals on geotechnical properties of clay liners: a review, Research Journal of Applied Sciences, Engineering and Technology, 2, 8, 765–775, (2010).
19. Sivapullaiah, P.V. Kaolinite-alkali interaction and effects on basic properties, Geotechnical and Geological Engineering, 23, 601-614, (2005).
20. Sridharan, A., Rao, S.M. ve Murthy, N.S., Liquid limit of montmorillonite soils, Geotechnical. Testing Journal, 9, 3, 156-159, (1986).
21. Bowders, J.J. ve Daniel, D.E., Hydraulic conductivity of compacted clay to dilute organic chemicals, Journal of Geotechnical and Geoenvironmental Engineering, 113, 1432 – 1448, (1987).
22. Daniel, D.E., Shackelford, C.D. ve Liao, W.P., Transport of inorganic compounds through compacted clay soil, Proc, Fourteenth Annual Res. Symp. on Land Disposal, Remedial Action, Incineration and Treatment of Hazardous Waste, EPA/600/9-88/021, U.S. Environmental Protection Agency, Cincinnati, Ohio, pp. 114-125, (1988).
23. Acar, Y.B. ve Olivieri, I., Pore fluid effects on the fabric and hydraulic conductivity of laboratory-compacted clay, Geotechnical. Engineering, 144-159, (1989).
24. Edil, T.B., Fox, P.J. ve Lan, L.T., Observational procedure for settlement of peat, Geo-Coast, 91, 3-6, (1991).
25. Gleason, M.H., Daniel, D.E. ve Eykholt, G.R., Calcium and sodium bentonite for hydraulic containment applications, Journal of Geotechnical and Geoenvironmental Engineering, 123, 438-445, (1997).
26. Petrov, R.J. ve Can, R.K.R., Geosynthetic clay liner (GCL) – chemical compatibility by hydraulic conductivity testing and factors impacting its performance, Journal of Geotechnical and Geoenvironmental Engineering, 34, 863–885, (1997).
27. Lin, L. ve Benson, C., Effect of wet-dry cycling on swelling and hydraulic conductivity of GCLs. Journal of Geotechnical and Geoenvironmental Engineering, 126, 1, 40-49, (2000).
28. Sridharan A. ve Prakash, K., (2000), Classification procedures for expansive soils, Proceedings of the Institution of Civil Engineers: Geotechnical Engineering, 143, 10, 235 – 240, (2000).
29. Sridharan, A., El-Shafei, A. ve Miura, N., Mechanisms controlling the undrained strength behavior of remolded ariake marine clays, Marine Georesources and Geotechnical, 20, 21-50, (2002).
30. Sharma, H.D. ve Lewis, S.P., Waste containment systems, waste stabilization, and landfills: design and evaluation, John Wiley & Sons Inc., no. 588, Canada, (1994).
31. Shackelford, C.D., Benson, C.H., Katsumi, T., Edil, T.B. ve Lin, L., Evaluating the hydraulic conductivity of GCLs permeated with non-standard liquids, Geotextiles and Geomembranes, 18, 133-161, (2000).
32. Jo, H.Y., Katsumi, T., Benson, C.H. ve Edil, T.B., Hydraulic conductivity and swelling of nonprehydrated GCLs permeated with single-species salt solutions, Journal of Geotechnical and Geoenvironmental Engineering, 127, 7, 557-567, (2001).
33. Kolstad, D.C., Benson, C.H. ve Edil, T.B., Hydraulic conductivity and swell of nonprehydrated geosynthetic clay liners permeated with multispecies ınorganic solutions. Journal of Geotechnical and Geoenvironmental Engineering, 130, 1236 – 1249, (2004).
34. Mishra, A.K., Ohtsubo, M., Li, L. ve Higashi, T., Effect of salt concentrations on the permeability and compressibility of soil-bentonite mixtures, Journal of the Faculty of Agriculture, Kyushu University, 50, 837-849, (2005).
35. Hamutcu, U., Arasan, S., Akbulut, R.K. ve Kurt, Z.N., Effect of salt solution temperature on the liquid limit of clay liners in solid waste disposal landfills, 8th International Congress on Advances in Civil Engineering, Eastern Mediterranean University, Famagusta, North Cyprus, 2, 65-73, (2008).
36. Kurt, Z.N., Arasan, S., Hamutcu, U. ve Akbulut, R.K. Effect of salt solution temperature on the liquid limit of clay liners in solid waste disposal landfills”, Geotechnical Symposium. Adana, Turkey, 383-390 (In Turkish with an English summary) (2007).
37. Mitchell, J.K., Fundamentals of Soil Behavior, 2nd Edn., John Wiley and Sons Inc., New York, (1993).
38. Kaya, A. ve Durukan, S., Utilization of bentonite embedded zeolite as clay liner, Applied Clay Science, 25, 83-91, (2004).