Geotechnical Evaluation of Some Soils from Part of Southwestern Nigeria, Usable as Liners in Waste Disposal Landfills

Abstract

Urbanization and population rise are major factors that contribute to increase quantity of waste generation and its disposal constraint especially in developing countries. This study investigates the geotechnical properties of five soils from southwestern Nigeria for their use as liners in sanitary landfill for disposal of solid waste. The required parameters for soils to be considered as liners were determined in accordance with the British Standard Institute. Results obtained showed that the percentage of fines range from 42% to 82% and index of plasticity values range from 25.0% to 32.6%. Clay activity varies between 0.47 and 0.88. Thus, the soils are classified as non-expansive clay of low to medium plasticity. The maximum dry density values at standard Proctor energy of compaction range from 1.46g/cm³ to 1.96g/cm³ while those obtained at modified Proctor energy range from 1.57g/cm³ to 2.09g/cm³ .The highest coefficient of permeability value obtained for all soils investigated is 2.99 x 10^-9m/s. All values compare favourably with those suggested by regulatory agencies. Consequently, they are suitable for use as liners in sanitary landfills.

Keywords: Liners, Nigeria, Landfill, Geotechnical, Sanitary, Waste Disposal, Soil, Clay Activity