International Research Journal of Engineering and Technology (IRJET)
e-ISSN: 2395 -0056
Volume: 04 Issue: 04 | Apr -2017
p-ISSN: 2395-0072
www.irjet.net
Study on amended landfill liner using bentonite and zeolite mixtures Shyla Joseph.A.1, Megha Varghese2 1Assistant 2PG
Professor, Department of Civil Engineering, SAINTGITS College of Engineering, Kottayam , Kerala, India Student, Department of Civil Engineering, SAINTGITS College of Engineering, Kottayam , Kerala, India
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Abstract – Landfill liner system has great importance in
preventing the movement of leachate to underground surfaces. The study makes an attempt to improve the locally available dump yard site soil using bentonite and zeolite mixtures. The variation in properties such as permeability (layered form) , dry density, OMC, consistency limits etc were studied. The result of permeability test shows that mix containing 40% dump yard site soil, 35% bentonite and 25% zeolite has the least permeability. Therefore the geotechnical properties make bentonite and zeolite mix an innovative material for liners in landfills. Key Words: landfill liner , leachate ,dump yard site soil , bentonite , zeolite
Fig.1 Bentonite
1. INTRODUCTION The generation of municipal solid waste increases with increase in economic growth and rapid urbanization. Open dumping, incineration and land filling are the traditional methods used for waste management. Landfill liners located below the municipal solid waste are the most important part of landfills .The main function of these liners, sometimes referred to as bottom liners, act as a hydraulic barriers to prevent the leaching of inorganic and organic pollutants into groundwater surfaces. The minimum Hydraulic conductivity of liner material used in the landfill should be 1x10 -7 cm/sec [1]. The commonly used liners are CCL, GCL and composite liners. But the usage of high-tech liner system like GCL may become uneconomical due to its import from elsewhere.
1.1 Local soil In this study dump yard soil was collected from dump yard site at Vadavathoor near Kottayam, Kerala. The properties of local soil are summarized in Table 1. 1.2 Bentonite Bentonite is an absorbent. It is composed of swelling clay mineral Montmorillonite Bentonite is naturally occurring clay with high swelling capacity, high ion exchange capacity and very low water permeability [2].The properties of bentonite is summarized in Table1.
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Table -1: Properties of local soil and bentonite PROPERTY
Specific gravity Liquid limit Plastic limit % Clay % Silt % Sand Maximum dry density Optimum moisture content Coefficient of permeability Free swell index pH
MATERIALS LOCAL BENTONITE SOIL 2.22 2.4 46% 464% 39% 42.5% 3 93 8 7 78 1.55g/cc 1.07g/cc 18.5% 51.3% 6.73x10-3cm/s 20.53x10-9 cm/s 23.07% 1000% 5.4 9.5
1.3 Zeolite
Zeolite is an adsorbent. It is hydrated aluminosilicate minerals made of interlinked tetrahedral of alumina and silica. They have open cage like framework that can trap heavy metals. They are very stable solids that resist kind of environmental condition that challenge many other materials. High temperatures do not bother them because they have very high melting point and they do not burn. The properties of zeolite are summarized in Table 2.
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