Impact of Initial Hydration of Bentonite on Its Plasticity Properties Change in Interaction with Organic Contaminant

Subject Areas : soil pollution

Vahidreza Ouhadi ¹ , Zeinab Aghaei ² , Kambiz Behnia ³

1 - Professor, Bu-Ali Sina University, Hamedan, Iran; Adjunct Prof., University of Tehran, College of Engineering, School of Civil Engineering, Tehran, Iran. *(Corresponding Author)
2 - M.Sc. in Geotechnical Engineering, University of Tehran, College of Engineering, School of Civil Engineering, Tehran, Iran
3 - Associate Professor, University of Tehran, College of Engineering, School of Civil Engineering, Tehran, Iran

Received: 2015-07-16 Accepted : 2016-11-01 Published : 2020-05-21

Keywords: Sodium-Bentonite, Initial Hydration, Organic Contaminant, Di-Electric Constant,

Abstract :

Background and Objective: The compacted clay liners (CCLs) due to their low permeability and suitable capability for contaminant retention are widely used in engineering waste disposal sites. Generally, the change in properties of soil pore fluid has a very distinguished impact on the behaviour of clayey soils. In spite of several researches, which have been performed on the process of clay and organic contaminant interaction, there are few researches on the influence of dielectric constant of organic contaminant and initial hydration of bentonite on the geotechnical and geo-environmental properties of organic contaminated bentonite. Such a process is very common in many industrial and waste disposal projects. Methods: This research was performed on sodium-bentonite soil samples which were exposed to two different organic materials (Ethanol and Acetic Acid) which have different dielectric constant. Furthermore, two different pre-hydration and post-hydration conditions were studied in this research. After achieving equilibrium condition, the influence of initial hydration and change on the dielectric constant of pore fluid upon interaction of organic material and bentonite was investigated. The investigation focuses attention on the plasticity properties of bentonite by the use of Atterberg limit tests. Findings: The achieved results indicate that in Casagrande's plasticity chart, two pre-hydrated sodium-bentonite soil samples which were exposed further to ethanol and acetic acid are classified as CH and shifted from CH to MH, respectively. Discussion and Conclusion: The change on the dielectric constant of pore fluid and different hydration conditions cause a change on the thickness of the double layer of clay fraction of the soil. This causes a noticeable change on the structure and behaviour of clay fraction of the soil sample. This variation on bentonite behaviour has been discussed based on the current available theory of double layer. Furthermore, the theoretical limitation for interpretation of results has been addressed.  

References:

1. Ouhadi, V.R., Goodarzi, A.R., 2007. Factors impacting the electro conductivity variations of clayey soils. Iranian Journal of Science & Technology, Transaction B: Engineering, Vol. 31, pp. 109-121.


2. Mitchell, J. K., 1960. The application of colloidal theory to the compressibility of clays. Commonwealth Science and Industry Research Organization, Melbourne, Australia, Vol. 2, pp. 92-97.


3. Ouhadi, V.R., Amiri, M., Goodarzi, A.R., 2012. The Special Potential of Nano-Clays for Heavy Metal Contaminant Retention in Geo-Environmental Projects, Journal of Civil and Surveying Engineering, Vol: 45, Issue: 6, pp. 631-642.


4. Sridharan, A., Rao, G.V., 1975. Mechanisms controlling the liquid limit of clays. Prof. Int. Conference on SMQFE, Istanbul,Vol. 1, pp. 65–74.


5. Ouhadi, V.R., Amiri, M., 2009. Interaction of Nano-Clays and Cu Contaminant in Geo-Environmental Projects. 6th Conf. Engineering Geology, Tarbiat Modares University, Tehran.


6. Yanful, E.K., Shikatani, K.S., Quirt, D.H., 1995. Hydraulic conductivity of natural soils permeated with acid mine drainage. Can. Geotech. J., Vol. 32, pp. 624–646.


7. Di Maio, C., 1996. Exposure of bentonite to the salt solution: osmotic and mechanical effects. Geotechnique, Vol. 46, pp. 695–707.


8. Wang, Y.H., Siu, W.K., 2006. Structure characteristics and mechanical properties of kaolinite soils. I. Surface charges and structural characterizations. Can. Geotech. J, Vol. 43, pp. 587–600.


9. Xue, Q., Zhang, Q., Liu, L., 2012. Impact of high concentration solutions on hydraulic properties of geosynthetic clay liner materials. Materials, Vol. 5, pp. 2326–2341.


10. Li, J.S., Xue, Q., Wang, P., Liu, L., 2013. Influence of leachate pollution on mechanical properties of compacted clay: a case study on behaviors and mechanisms. Eng. Geol, Vol. 167, pp. 128–133.


11. Li, Z., Katsumi,T., Inui, T.,Takai, A., 2013. Fabric effect on hydraulic conductivity of kaolin under different chemical and biochemical conditions. Soils Found, Vol. 53, pp. 680–691.


12. Sridharan, A., El-Shafei, A., Miura, N., 2000. A study on the dominating mechanisms and parameters influencing the physical properties of Ariake clay. International Association of Lowland Technology Journal, Vol. 2, pp. 55–70.


13. Olgun, M., and Yıldız, M., 2010. Effect of organic fluids on the geotechnical behavior of a highly plastic clayey soil. Vol, 48, pp. 615-621.


14. Yong, R.N., Warkentin, P.B., 1966. Introduction to soil behavior. Mc Millan Co., London, p. 451.


15. Liu, Y., Gates, W.P., Bouazza, A., 2013. Acid induced degradation of the bentonite component used in geosynthetic clay Liners. Geotextiles and Geomembranes, Vol. 36, pp. 71-80.


16. Spagnoli, G., Stanjek, H., and Sridharan, A., 2012. Influence of ethanol/water mixture on the undrained shear strength of pure clays. Bulletin of Engineering Geology and the Environment, Vol. 71, pp. 389-398.
    
    
    1. Hendershot W.H., Duquette M., 1986. A simple barium chloride method for determining cation exchange capacity and exchangeable cations, Soil Sci. Soc. Am. J., Vol. 50, pp. 605-608.
    
    
    2. Ouhadi, V.R., Amiri, M., 2014. Interaction of Nano-Clays and Cu Contaminant in Geo-Environmental Projects. Journal of Environmental Science and Technology, Vol. 16 (160), 75-87
    
    
    3. Ouhadi, V.R., Amiri, M., 2011. Geo-environmental Behaviour of Nanoclays in Interaction with Heavy Metals Contaminant, Amirkabir Journal of Civil Engineering, Vol. 42, Issue 3, pp 29-36.
    
    
    4. Moavenian, M.H., Yasrobi, SH. S., 2008. Volume change behavior of compacted clay due to organic liquids as permeant. Applied Clay Science, Vol. 39, pp. 60-71.
    
    

17. Mitchell, J.K., Soga, K., 2005. Fundamentals of soil behaviour. 3th edition, John Wiley and Sons, p. 529.


18. Puma, S., Dominijanni, A., Manassero, M., Zaninetta, L., 2015. The role of physical pretreatments on the hydraulic conductivity of natural sodium bentonites. Geotextiles and Geomembranes, Vol. 43, pp. 263-271.


19. ASTM, April 1999. ASTM Standards and Other Specifications and Test Methods on the Quality Assurance of Landfill Liner Systems. ASTM, 1916 Race Street, Philadelphia, PA.