An evaluation of cement-based waste forms using the results of approximately two years of dynamic leaching

Journal Article · Thu Jan 01 04:00:00 EST 1987 · Nucl. Chem. Waste Manage.; (United States)

DOI:https://doi.org/10.1016/0191-815X(87)90007-6· OSTI ID:5863120

Cote, P L; Constable, T W; Moreira, A

The leachability of cement-based waste forms was assessed using a dynamic leaching test, in which solidified waste cubes are immersed in distilled water, and the water renewed at variable time intervals which were calculated assuming bulk diffusion controlled leaching. The four waste forms assessed were produced by solidifying a synthetic sludge containing arsenic, cadmium, chromium and lead, using additives of lime and fly ash, fly ash and cement, bentonite and cement, and cement and soluble silicates. The cumulative fractions of cadmium, chromium and lead leached were smaller than 1% for all the waste forms studied. Arsenic leached more readily, especially from the soluble silicates-cement waste form, attaining 15% after 665 days. The pH of the leachates remained alkaline throughout the testing period. For cadmium, chromium and lead, the rate of leaching was explained by diffusion of the soluble fraction through the pore system of the waste form matrix. For arsenic, the rate of leaching was linear, and it is postulated that the rate was limited by the mobilization of the arsenite ion resulting from carbonation of basic calcium arsenite.

• Research Organization: Environment Canada, Conservation and Protection, Wastewater Technology Centre, P.O. Box 5050, Burlington, Ontario L7R 4A6
• OSTI ID: 5863120
• Journal Information: Nucl. Chem. Waste Manage.; (United States), Journal Name: Nucl. Chem. Waste Manage.; (United States) Vol. 7:2; ISSN NCWMD
• Country of Publication: United States
• Language: English

Related Subjects

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053000 -- Nuclear Fuels-- Environmental Aspects
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
ADDITIVES
AEROSOL WASTES
ALKALINE EARTH METAL COMPOUNDS
ARSENIC
ASHES
BENTONITE
BUILDING MATERIALS
CADMIUM
CALCIUM COMPOUNDS
CARBONATE ROCKS
CEMENTING
CEMENTS
CHEMICAL ANALYSIS
CHEMICAL COMPOSITION
CHEMICAL REACTION YIELD
CHROMIUM
CLAYS
DIFFUSION
DISPERSIONS
DISSOLUTION
DISTILLATION
ELEMENTS
ENVIRONMENTAL TRANSPORT
EVALUATION
FLY ASH
HYDROGEN COMPOUNDS
LEACHATES
LEACHING
LEAD
LIMESTONE
MASS TRANSFER
MATERIALS
MATERIALS TESTING
MATHEMATICAL MODELS
MATHEMATICS
METALS
MIXTURES
OXYGEN COMPOUNDS
PH VALUE
PHASE TRANSFORMATIONS
POROSITY
QUANTITATIVE CHEMICAL ANALYSIS
RADIOACTIVE MATERIALS
RADIOACTIVE WASTES
RADIONUCLIDE MIGRATION
REGRESSION ANALYSIS
RESIDUES
ROCKS
SEDIMENTARY ROCKS
SEMIMETALS
SEPARATION PROCESSES
SILICATES
SILICON COMPOUNDS
SOLIDIFICATION
SOLUBILITY
SOLUTIONS
STATISTICS
TESTING
TRANSITION ELEMENTS
WASTE FORMS
WASTES
WATER
YIELDS