Effect of Acidic Mine Drainage on the Mechanical and Hydraulic Properties of Three Geosynthetics

Abstract

This paper describes a study of the physical effects of exposing three geosynthetics commonly used in waste containment systems (a geomembrane, geotextile, and drainage geocomposite) to a synthetic acidic mine drainage (AMD) from metallic mine wastes in an environment with limited access to oxygen and ultraviolet (UV) radiation. The geosynthetic materials were immersed in tanks containing synthetic AMD, acidic water, and de-ionized water at 20, 40, or 60°C. Specimens were periodically removed from the tanks over a 22 month period and tested to determine their mechanical (tensile strength, puncture strength, and trapezoidal tear strength) and hydraulic properties (transmissivity and permittivity). Results of the tests were evaluated using analysis of variance (ANOVA) and linear regression to determine if statistically significant changes in the mechanical or hydraulic properties occurred during exposure. Both ANOVA and linear regression showed that none of the mechanical or hydraulic properties exhibited statistically significant changes, regardless of the immersion liquid, immersion temperature, or duration. These findings are consistent with those of other studies conducted with synthetic and actual AMD where exposure to oxygen and UV radiation was minimal.