Diffusion through Pulverized Stone Compared to Other Mineral Barrier Materials

Abstract

Construction of a waste disposal site requires an effective barrierthat separates waste from a sub-base and minimizes the migrationof contaminants from the site to an aquifer. Barrier layers mostoften used are natural clayey deposits or compacted clay liners andPEHD geomembranes. However, some regions, the Croatian karstfor example, are mostly short of clay. For this reason, the use ofpulverized stone, the by-product in the building-stone industry – as apotential liner material was investigated. Considering diffusion is animportant mechanism of contaminant transport through barriers, thispaper describes the method and apparatus for determining the diffusioncoefficient of pulverized stone. Measured diffusion values wererelated to sample compaction and compared with the physical propertiesof clay, geosynthetic clay liners and PEHD geomembranes. Otherphysical properties of pulverized stone such as the filtration coefficient,density and particle size distribution are also presented. Finally,the suitability of pulverized stone for barrier construction is discussedbased on the results obtained.