Utilization of marine clay as a bottom liner material in engineered landfills

A typical Malaysian marine clay was evaluated for its suitability as a bottom liner material to minimize leachate migration in engineered landfills. Grading, plasticity characteristics, unconfined compressive strength, volumetric shrinkage strain, permeability, geochemistry, mineralogical, and microstructural tests were conducted to characterize the clay as well as to evaluate it's potential as an effective bottom liner material. The work findings reveal that the clay possesses minimal shrinkage potential and adequate strength to support the overburden pressure imposes by the waste. The permeability of the clay increased upon permeation with leachate but still met the Malaysian regulatory requirement of ≤ 10-8 m/s specified by the regulatory authority. X-ray diffraction analysis shows that the soil mineralogical composition was unaltered after permeation with leachate. Nonetheless, the appearances of two new low-intensity hercynite peaks were observed for the leachate permeated sample. These new peaks, however, did not adversely affect the hydro-mechanical properties of the clay. The results demonstrate that the studied marine clay can be employed as a bottom liner material in engineered landfills, hence providing a value-added application of the construction waste material.