Suitability of Shale Treated with Palm Kernel Shell Ash and Pulverized Palm Kernel Shell As Landfill Liners at Nguzu Edda, Southeastern Nigeria

Abstract

Wastes are mostly disposed of in landfills, which pose threat to soil and groundwater as a result of percolation of leachate. Therefore, barrier soils are required for the lining of a landfill to prevent seepage of leachate into the surrounding groundwater system. In this regard, the suitability of ten shale samples treated with 0-12 % (increments of 2 %) proportion of palm kernel shell ash (PKSA) and pulverized palm kernel shell (PPKS) by dry weight of the shale samples were evaluated for uses as landfill liner. The samples were subjected to series of geotechnical tests to determine the index properties, and strength characteristics of the natural and treated shale using West African standard (WAS) and Modified AASHTO (MAS) compactive energy levels for comparison purposes. The shale was classified as A-7-5. The atterberg limits test results show that liquid and plastic limits generally decreased, while the plasticity index (PI) increased with increase in PKSA and PPKS contents. The results also demonstrated that maximum dry density (MDD), volumetric shrinkage strain (VSS) and hydraulic conductivity decreases significantly while optimum moisture content (OMC) increases with increase in PKSA and PPKS contents for the both energy levels. The maximum strength of 380.30 and 448.70 KPa were recorded at 4 % of the stabilizers. The findings affirmed that the samples met the requirements for landfills liner, although PPKS was more effective than PKSA for both energy levels. Moreover, the addition of PKSA and PPKS to liners can also be an alternative means of its disposal.