Utilization of bagasse ash in the compacted clay liner

Abstract

Landfills are highly engineered waste containment systems, designed to minimize the impact of waste on the environment. In modern landfills, the waste is contained by liner and cover systems. Due to the scarcity of natural clay, the commercially available bentonite is often used in the construction of liners. The bentonite layer generally shrinks during the summer, and therefore, severe cracks are formed; thus, it fails to control the migration of leachate. In the past, various additives have been used to stabilize bentonite. In recent years, studies have been focused on using reactive materials as additives so that they can stabilize bentonite, and also, it can adsorb the heavy metals from the leachates. The sugar industry produces fly ash, known as the bagasse ash, which causes a disposal problem. This bagasse ash is found to be a good absorbent material. Hence, a study was carried out to assess the stabilization of compacted clay liner blended with bagasse ash. Several tests, including consistency limits and hydraulic conductivity tests, have been performed by blending different contents of bagasse ash. From the test results and their analysis, it is observed that 40% of bagasse ash can be mixed with bentonite so that the essential requirements of the liner are maintained.