International Research Journal of Engineering and Technology (IRJET)
e-ISSN: 2395 -0056
Volume: 04 Issue: 05 | May -2017
p-ISSN: 2395-0072
www.irjet.net
Solidification/Stabilization (S/S) of Lead Contaminated Soil Athira Sindhu Manikantan1, Rani V2 1Mtech:
Geotechnical Engineering, Dept of Civil Engineering, Marian Engineering College, Kerala, India Professor, Dept of Civil Engineering, Marian Engineering College, Trivandrum, India
2Associate
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Abstract - An Heavy metal contamination in soils is
mineralogy and clay content and also causes alterations in soil properties like pH, swell shrink behaviour, permeability, shear strength and compressibility.
widespread in India as well as other parts of the world .These heavy metals generate leachate during leaching process causing the soil and ground water contamination during its interaction with the both. This is not only harmful for the subsurface water aquifers but also for structures existing on it. Unlike organic compounds that can be destroyed, heavy metals can only be covered, isolated, removed and recycled, moved to a safer location, or transformed into a less toxic form.
With greater public awareness of the implications of heavy metal contaminated soils on human and animal health and due to need for uncontaminated fields or ‘green areas’ there has been increasing interest amongst the scientific community in the development of technologies to remediate contaminated sites and facilitate sustainable industrial development. Amidst the numerous soil remediation methods in use, stated that soil immobilization or stabilization /solidification (S/S) appears the most effective due to its binding ability or entrapping of waste within a solid cementitious matrix and cost effectiveness. In the present study high plastic clay is artificially contaminated using Lead Acetate and then an attempt is made to immobilize the soil using a mixture of Flyash and OPC. The variation in geotechnical properties due to contaminant addition and amendment addition to the contaminated soil is studied.
Solidification/stabilization (S/S) is an effective technique for reducing the leachability of these contaminants in soils. In this technique the migration of potential contaminants from generated leachate is reduced by the incorporation of various amendments which isolates the waste within a solid cementitious matrix. In the present study high plastic clay was artificially contaminated using Lead Acetate at different concentration and an attempt is made to remediate it using a mixture of Class F fly ash and OPC. The impact of the treatment was evaluated by means of compressibility, plasticity tests and toxicity characteristic leaching procedure (TCLP).
2. MATERIALS AND METHODS
Key Words: Stabilization/solidification, TCLP, Heavy metal remediation, Lead contamination
2.1 High Plastic Clay Calcium bentonite used in this study was procured from a quarry near Coimbatore in Tamilnadu. The properties of the samples are presented in Table I. The soil sample was artificially contaminated by mixing it with different molarity of lead acetate solution. The SEM image of Ca Bentonite Clay is shown in Fig 1.
1. INTRODUCTION The engineering and index properties of soil are affected by past land use, current activities on the site and nearness to pollution sources. The insistent and rapid industrialization of developing countries calls for the need to effectively dispose and manage generated wastes. Every year the solid wastes dumped into the soil are increasing at an alarming rate all over the world. The problem of soil pollution is compounded by the use of agrochemicals like pesticides, fungicides, bactericides, insecticides, fertilizers etc. The soil pollution differs from air and water pollution in the sense that the pollutants in soil remain in direct contact with the soil for relatively longer periods and different pollutants in their tendency to end up in water held in the soil or in the underlying groundwater, volatilize into the air or bind tightly to the soil. Among these contaminants heavy metals in the industrial waste constitute a major group of inorganic chemical hazards. These contaminants affects the soil
Š 2017, IRJET
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Impact Factor value: 5.181
Table -1: Properties of Calcium Bentonite Clay Soil Properties Specific Gravity Liquid limit (%) Plastic limit (%) Plasticity index (%) IS classification OMC (%) Dry density(g/cc) % clay % silt % sand 2 UCC strength (kN/m ) Free swell index
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Values Obtained 2.26 110 46 64 CH 19.38 1.46 77.5 16.2 6.3 92.33 6.27
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