The Experts below are selected from a list of 69 Experts worldwide ranked by ideXlab platform

Adrian O. Eberemu - One of the best experts on this subject based on the ideXlab platform.

  • Evaluation of bagasse ash treated lateritic soil as a potential Barrier material in waste Containment application
    Acta Geotechnica, 2013
    Co-Authors: Adrian O. Eberemu
    Abstract:

    Laboratory tests were conducted on a reddish-brown lateritic soil treated with up to 12 % bagasse ash to assess its suitability in waste Containment Barriers applications. Soil samples were prepared using four compaction energies (i.e. reduced Proctor, standard Proctor, West African Standard or ‘intermediate’ and modified Proctor) at −2, 0, 2 and 4 % moulding water content of the optimum moisture content (OMC). Index properties, hydraulic conductivity ( k ), volumetric shrinkage and unconfined compressive strength (UCS) tests were performed. Overall acceptable zones under which the material is suitable as a Barrier material were obtained. Results recorded showed improved index properties; hydraulic conductivity and UCS with bagasse ash treatment up to 8 % at the OMC. Volumetric shrinkage strain increased with higher bagasse ash treatment. Based on the overall acceptable zone obtained, an 8 % optimal bagasse ash treatment of the natural lateritic soil makes it suitable for use in waste Containment Barrier application.

  • the use of compacted tropical clay treated with rice husk ash as a suitable hydraulic Barrier material in waste Containment applications
    Waste and Biomass Valorization, 2013
    Co-Authors: Adrian O. Eberemu, Agapitus A Amadi, K J Osinubi
    Abstract:

    Protection of our environment from pollutants emanating from wastes generated by man made activities and disposal systems in less developed countries is now a matter of growing concern. Laboratory tests were conducted on compacted tropical clay treated with up to 16 % rice husk ash (RHA) an agro-industrial waste to access its suitability in waste Containment Barrier application. Soil–RHA mixtures was compacted using standard Proctor, West African Standard and modified Proctor efforts at −2, 0, 2 and 4 % of optimum moisture content. Index properties, volumetric shrinkage, hydraulic conductivity, and unconfined compressive strength tests were performed. Overall acceptable zones under which the material was suitable (low hydraulic conductivity  200 kN/m2) were obtained. Results suggest the suitability of this material in waste Containment Barrier application for up to 8 % RHA treatment,which will ameliorate the environmental problems created by this agro-industrial waste.

H F Sen - One of the best experts on this subject based on the ideXlab platform.

  • potential use of densified polymer pastefill mixture as waste Containment Barrier materials
    Waste Management, 2010
    Co-Authors: M Fall, J Celestin, H F Sen
    Abstract:

    Abstract Mining activities generate a large amount of solid waste, such as waste rock and tailings. The surface disposal of such waste can create several environmental and geotechnical problems. Public perception and strict government regulations with regards to the disposal of such waste compel the mining industry to develop new strategies which are environmentally sound and cost effective. In this scenario, recycling of such waste into mining or civil engineering construction materials have become a great challenge for the mining and civil engineering community. Hence, in this study, taking advantage of the inherent low hydraulic conductivity of paste tailings (pastefill), small amounts (0.05, 0.1, 0.2, 0.5%) of a super absorbent polymer (SAP) are added to the latter after moisturizing the tailings. The resulting densified polymer-pastefill (PP) materials are compacted and submitted to permeability tests at room temperature and performance tests under cyclic freeze–thaw and wet–dry conditions to evaluate their suitability as a Barrier for waste Containment facilities. Valuable results are obtained. It is found that the hydraulic conductivity of the proposed Barrier material (PP) decreases as the amount of SAP increases. Hydraulic conductivity values as low as 1 × 10−7 and 6 × 10−9 cm/s are obtained for PPs which contain 0.1–0.5% SAP, respectively. The PP material also shows relatively good resistance to cyclic freeze–thaw and wet–dry stresses. The results show that negligible to acceptable changes in hydraulic conductivity occur after five freeze–thaw and six wet–dry cycles. None of the changes reach one order of magnitude. As a final step, a cost analysis is undertaken to evaluate the economical benefits that could be drawn from such a proposed Barrier material. When compared to a conventional compacted sand–bentonite Barrier with 12% bentonite concentration, it is found that the benefit realized could be estimated to 98, 96 and 90% when using PP material that contains 0.10, 0.20 and 0.5% of SAP. From this study, it can be concluded that PP materials show encouraging performance properties for Barrier design.

M Fall - One of the best experts on this subject based on the ideXlab platform.

  • potential use of densified polymer pastefill mixture as waste Containment Barrier materials
    Waste Management, 2010
    Co-Authors: M Fall, J Celestin, H F Sen
    Abstract:

    Abstract Mining activities generate a large amount of solid waste, such as waste rock and tailings. The surface disposal of such waste can create several environmental and geotechnical problems. Public perception and strict government regulations with regards to the disposal of such waste compel the mining industry to develop new strategies which are environmentally sound and cost effective. In this scenario, recycling of such waste into mining or civil engineering construction materials have become a great challenge for the mining and civil engineering community. Hence, in this study, taking advantage of the inherent low hydraulic conductivity of paste tailings (pastefill), small amounts (0.05, 0.1, 0.2, 0.5%) of a super absorbent polymer (SAP) are added to the latter after moisturizing the tailings. The resulting densified polymer-pastefill (PP) materials are compacted and submitted to permeability tests at room temperature and performance tests under cyclic freeze–thaw and wet–dry conditions to evaluate their suitability as a Barrier for waste Containment facilities. Valuable results are obtained. It is found that the hydraulic conductivity of the proposed Barrier material (PP) decreases as the amount of SAP increases. Hydraulic conductivity values as low as 1 × 10−7 and 6 × 10−9 cm/s are obtained for PPs which contain 0.1–0.5% SAP, respectively. The PP material also shows relatively good resistance to cyclic freeze–thaw and wet–dry stresses. The results show that negligible to acceptable changes in hydraulic conductivity occur after five freeze–thaw and six wet–dry cycles. None of the changes reach one order of magnitude. As a final step, a cost analysis is undertaken to evaluate the economical benefits that could be drawn from such a proposed Barrier material. When compared to a conventional compacted sand–bentonite Barrier with 12% bentonite concentration, it is found that the benefit realized could be estimated to 98, 96 and 90% when using PP material that contains 0.10, 0.20 and 0.5% of SAP. From this study, it can be concluded that PP materials show encouraging performance properties for Barrier design.

J Celestin - One of the best experts on this subject based on the ideXlab platform.

  • potential use of densified polymer pastefill mixture as waste Containment Barrier materials
    Waste Management, 2010
    Co-Authors: M Fall, J Celestin, H F Sen
    Abstract:

    Abstract Mining activities generate a large amount of solid waste, such as waste rock and tailings. The surface disposal of such waste can create several environmental and geotechnical problems. Public perception and strict government regulations with regards to the disposal of such waste compel the mining industry to develop new strategies which are environmentally sound and cost effective. In this scenario, recycling of such waste into mining or civil engineering construction materials have become a great challenge for the mining and civil engineering community. Hence, in this study, taking advantage of the inherent low hydraulic conductivity of paste tailings (pastefill), small amounts (0.05, 0.1, 0.2, 0.5%) of a super absorbent polymer (SAP) are added to the latter after moisturizing the tailings. The resulting densified polymer-pastefill (PP) materials are compacted and submitted to permeability tests at room temperature and performance tests under cyclic freeze–thaw and wet–dry conditions to evaluate their suitability as a Barrier for waste Containment facilities. Valuable results are obtained. It is found that the hydraulic conductivity of the proposed Barrier material (PP) decreases as the amount of SAP increases. Hydraulic conductivity values as low as 1 × 10−7 and 6 × 10−9 cm/s are obtained for PPs which contain 0.1–0.5% SAP, respectively. The PP material also shows relatively good resistance to cyclic freeze–thaw and wet–dry stresses. The results show that negligible to acceptable changes in hydraulic conductivity occur after five freeze–thaw and six wet–dry cycles. None of the changes reach one order of magnitude. As a final step, a cost analysis is undertaken to evaluate the economical benefits that could be drawn from such a proposed Barrier material. When compared to a conventional compacted sand–bentonite Barrier with 12% bentonite concentration, it is found that the benefit realized could be estimated to 98, 96 and 90% when using PP material that contains 0.10, 0.20 and 0.5% of SAP. From this study, it can be concluded that PP materials show encouraging performance properties for Barrier design.

P E Raison - One of the best experts on this subject based on the ideXlab platform.

  • new hermetic sample holder for radioactive materials fitting to siemens d5000 and bruker d8 x ray diffractometers application to the rietveld analysis of plutonium dioxide
    Journal of Applied Crystallography, 2004
    Co-Authors: Renaud C Belin, Philippe J Valenza, Muriel Reynaud, P E Raison
    Abstract:

    A new hermetic sample holder to be used with radioactive or air- and moisture-sensitive samples has been developed; it has been designed to fit most of the commercial Siemens/Bruker diffractometers (e.g. D5000 and D8 series). Thanks to the design of the sample holder and to a sample preparation process allowing two-Containment-Barrier protection, X-ray data can be collected using a standard uncontaminated diffractometer mounted in a Bragg–Brentano geometry. The design offers very accurate and reliable sample positioning. In order to demonstrate the high quality of the data obtained, the Rietveld analysis of plutonium dioxide is presented. Good agreement between the refinement and published data demonstrates the quality of the sample preparation and the accuracy of the sample holder. High-quality X-ray diffraction powder patterns can be recorded for use in Rietveld refinements, even on highly absorbing radioactive materials.