Hydraulic performance of compacted foundry sand bagasse ash mixture permeated with municipal solid waste leachate
Electronic Journal of Geotechnical Engineering
Department of Civil Engrg., Ahmadu Bello University, Zaria 810001, Nigeria; Department of Civil Engrg., Nigerian Defense Academy, Kaduna, Nigeria
Foundry sand mixed with up to 8% bagasse ash by weight of dry soil was evaluated for use as a suitable hydraulic barrier material. Tests were carried out on the foundry sand - bagasse ash mixtures to determine the index properties and compaction characteristics. The relationship between hydraulic conductivity of the mixtures compacted using the British Standard light (BSL) energy (relative compaction = 100%) with molding water content, bagasse ash content and unit weight were determined. Furthermore, specimens were sequentially permeated with water and municipal solid waste (MSW) landfill leachate to determine the hydraulic conductivity values of the foundry sand - bagasse ash mixtures. Test results show that the regulatory minimum hydraulic conductivity (k) value of 1 × 10 -9 m/s or lower required for a material to be used in waste containment application can be achieved when foundry sand is treated with 4 % bagasse ash, prepared at molding water content in the range 11.2 - 15.4% and compacted to a unit weight of at least 17.56 kN/m 3. Results for specimen permeated with MSW leachate showed that foundry sand treated with 4% bagasse ash met the regulatory minimum value for barrier materials. Generally hydraulic conductivity values of specimens treated with MSW decreased by factors in the range 1.12-5.71, but above 6% bagasse ash treatment the value increased by a factor of 1.32, which practically is considered insignificant. The study showed that foundry sand treated with 4% bagasse ash can be used as a barrier material in municipal waste containment facilities.
Ash contents; Ash mixtures; Barrier material; British Standards; Dry soil; Hydraulic barrier; Hydraulic performance; Index properties; Leachates; Minimum value; Molding water content; Municipal solid waste landfills; Municipal waste; Relative compaction; Unit weight; Waste containment; Compaction; Foundry sand; Hydraulic conductivity; Leaching; Mixtures; Molding; Municipal solid waste; Soil testing; Bagasse; ash; compaction; hydraulic conductivity; landfill; leachate; municipal solid waste; sand; waste facility