Use of Secondary Waste Minerals as a Novel Low –CostCementitious Landfill Liner

Use of Secondary Waste Minerals as a Novel Low –CostCementitious Landfill Liner

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Part of #Use of Secondary Waste Minerals as a Novel Low –CostCementitious Landfill Liner# :

Publishing year : 2005

Conference : The 2nd International Conference on Concrete and Development

Number of pages : 14

Abstract: Conventional liners have been made with clay and HDPE membranes, supporting packed aggregate layers. When cementitious materials are used for the containment of waste, they act in two different, and sometimes conflicting, ways. The first is a chemical containment in which the leachate passing through the barrier is buffered to a high pH thereby substantially reducing the solubility of many harmful species and promoting sorption on the matrix. Chemical barriers have been extensively researched for nuclear waste management and this paper reports on the development of chemical barriers for non-nuclear waste management using a new alternative technology in which low cost concrete liners can be constructed using materials that are considered to be without wastes by their primary producers. It focuses on the ability of a cementitious barrier to chemically condition liquid discharges, neutralizing organic acids and reducing the solubility of a priority pollutant. This is similar to the way in which cement suppresses actinide leaching in the disposal of nuclear waste. In this paper, the required properties of cementitious mixes for this purpose are discussed. The results of an extensive investigation into potential mixtures using different mineral wastes are presented and the measured properties are compared with those required. All of the mixtures that have been investigated contain large amounts of secondary materials. If these materials which have the potential for use as a binder or as aggregate materials for concrete were treated as waste, their disposal costs would be high, so mixtures can be designated as "negative cost mixes". The results indicate that many of these mixes are well suited to this application