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

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

First evidence of tick-borne protozoan pathogens, babesia sp. And hepatozoon canis, in red foxes (vulpes vulpes) in Serbia

Tick-borne haematozoans cause severe diseases in domestic animals, and some of them have zoonotic potential. The results of previous studies in Europe point to the important role of foxes in natural endemic cycles of several tick-borne pathogens, including protozoa. The aim of the present research was to acquire information on the prevalence and distribution of tick-borne protozoan parasites among foxes in Serbia. Legally hunted foxes from 14 localities throughout Serbia were analysed. Spleen samples were collected from 129 animals and tested for the presence of Babesia spp. and Hepatozoon spp. by PCR. In total, 79/129 (61.2%) of the tested foxes were positive for H. canis, while the presence of two Babesia species was confirmed: B. vulpes (37/129, 28.7%) and B. canis (1/129, 0.8%). Co-infection with B. vulpes and H. canis was present in 26/129 (20.2%) foxes and one animal (1/129, 0.8%) was co-infected by B. canis and H. canis. The results of this study indicate the important role of foxes in the epizootiology of B. vulpes and H. canis in the Republic of Serbia and stress the need for further research to clarify all elements of the enzootic cycle of the detected pathogens, including other reservoirs, vectors, and transmission routes