Long-term hydraulic conductivity of compacted clay permeated with landfill leachates

Abstract

This paper studies the effects of bio-clogging on hydraulic conductivity of compacted soils used as landfill liners. Landfill leachate contains a large amount of microorganism and bacterial biomass, which was likely to cause bio-clogging in landfill liners. To interpret the effect of bio-clogging on hydraulic property of compacted clays, in this study, a series of laboratory-scale hydraulic conductivity tests were conducted. The long term hydraulic conductivity of compacted clays was measured with distilled water, landfill leachate and one type of nutrient solution. The laboratory test results show that the hydraulic conductivity of compacted clays permeated with distilled water stabilized at approximately 3.77 × 10 -8 cm/s, and the hydraulic conductivity of compacted clays permeated with landfill leachate or nutrient solution ranged between 1.1 × 10 -8 cm/s and 5.22 × 10 -9 cm/s. Such a significant difference was attributed to the effect of bio-clogging. The microorganism and bacterial biomass reduced the hydraulic conductivity up to one order of magnitude. This study indicated that the bio-clogging is approximately a feasible method to create low-cost and low-hydraulic conductivity barriers by using locally available clayed soils.

A Constitutive Model Study of Chemical Corrosion Sandstone Based on Support Vector Machine and Artificial Bee Colony Algorithm

“…The change in the relationship between stress and the related strain of rock under external force is referred to as the constitutive relationship of rock, which is a mathematical formula that describes the mechanical characteristics of rock [1][2][3]. Geotechnical engineering places a high priority on predicting and understanding rock mass stability.…”