Mechanisms of metal containment resulting from the solidification of a commercially produced stabilized waste
- Imperial Coll., London (United Kingdom). Centre for Environmental Control and Waste Management
The stabilized filter cake produced at a commercial stabilization/solidification plant, which treats a wide variety of inorganic solid wastes and effluents, has been characterized, and subsequently solidified by adding increasing amounts of cement and fly ash. This stabilized waste interacts with the cementitious additives so that the normal products of hydration are no longer produced. a solidified material is, however, still formed, and ettringite is the main crystalline product. The degree of chemical containment has been determined by completing single extraction batch leach tests under increasingly aggressive conditions. Results indicate that hazardous heavy metals are well retained by the solidified wastes, while they are readily leached from the stabilized filter cake. The concentrations of metals released from the stabilized waste and the solidified materials exhibit the same behavior as a function of leachate pH. This demonstrates that a major effect of the cementitious additives is to change the composition of the leaching fluid. The addition of solidified wastes containing increasing amounts of cementitious additives is to an acidic leachant causes Ca{sup 2+} to leach at a concentration determined by the acidity of the leachant. Mixes containing low additions of cementitious additives cannot release sufficient Ca{sup 2+}, the leachate remains acidic, and heavy metals present in the waste are able to leach.
- OSTI ID:
- 549375
- Report Number(s):
- CONF-931119-; TRN: IM9751%%58
- Resource Relation:
- Conference: 3. international symposium on stabilization/solidification of hazardous, radioactive and mixed wastes, Williamsburg, VA (United States), 1-5 Nov 1993; Other Information: PBD: 1996; Related Information: Is Part Of Stabilization and solidification of hazardous, radioactive, and mixed wastes: 3. volume; Gilliam, T.M.; Wiles, C.C. [eds.]; PB: [740] p.; ASTM special technical publication 1240
- Country of Publication:
- United States
- Language:
- English
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