Diffusion through Pulverized Stone Compared to Other Mineral Barrier Materials

Construction of a waste disposal site requires an effective barrier that separates waste from a sub-base and minimizes the migration of contaminants from the site to an aquifer. Barrier layers most often used are natural clayey deposits or compacted clay liners and PEHD geomembranes. However, some regions, the Croatian karst for example, are mostly short of clay. For this reason, the use of pulverized stone, the by-product in the building-stone industry – as a potential liner material was investigated. Considering diffusion is an important mechanism of contaminant transport through barriers, this paper describes the method and apparatus for determining the diffusion coefficient of pulverized stone. Measured diffusion values were related to sample compaction and compared with the physical properties of clay, geosynthetic clay liners and PEHD geomembranes. Other physical 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 discussed based on the results obtained