Tracer Transport Study in Fly Ash being Used as Landfill Material

Abstract

The suitability of fly ash for its use as landfill material is investigated by examining the fluid transport process through fly ash beds in different compositions with sand. The columns of two different diameters, 3 cms and 4 cms respectively, were designed to carry out the experiments. Glucose solution of known concentration was selected as an ideal tracer to characterize the flow mechanism of tracer through different arrangements of beds. It is suggested that the fly ash use, as a landfill material, may be preferred in appropriate composition with sand or other soil material in comparison to the existing practice of using fly ash only as a fill material. It is observed that a 3:1 mixture of fly ash and sand with 5% lime as binding material shows appreciably faster rate of dispersion of the tracer solution. This design mix, following the relationship between fly ash's pozzolanic ingredient and desired geo-technical properties, also facilitates attaining dual usage, namely, a soil-like consistency for use as a fill material and concrete-like characteristics for use as a final cover.