Assessment of one and two-dimensional molecular diffusion of chloride ion through ceramic powder waste-bentonite mixture as landfill liner

Abstract

One of the major problem in constructing liners that are exposed to leachate is that every material is not able to prevent transmission of contaminant to protect water resource. Lack of water resources worldwide demands for a prompt measure in order to protect extant resources and to minimize wastage growing threat on the environment. In this study, one & two-dimensional (1-D) & (2-D) diffusion test of chloride ion coupled with conductivity were conducted on Ceramic Powder Waste-Bentonite mixture (CPW-B) to investigate the capability of its use as contaminant barrier liner and its potential impact on surroundings. Parameters considered for the laboratory study were Bentonite content (BC) and Leachate height (LH). The test results indicate that there is a significant improvement in diffusion coefficient of the mixture compared with pure CPW. The compound is able to meet the standards when 30% dry weight of bentonite at least is added in CPW-B mixtures. Furthermore, the hydraulic conductivity of compounds in various pressures and variety of bentonite content was determined by the flexible wall triaxial hydraulic conductivity apparatus. The obtained hydraulic conductivities is in the range of values recommended for the compacted clayey liners and therefore, this material is acceptable in terms of advection transport.