Aluminoborosilicate Waste Glass Dissolution under Alkaline Conditions at 40°C: Implications for a Chemical Affinity-Based Rate Equation

Journal Article · Mon Feb 25 04:00:00 EST 2008 · Environmental Chemistry, 5(1):73-85

DOI:https://doi.org/10.1071/EN07058· OSTI ID:925479

Pierce, Eric M; Richards, Emily L; Davis, Aaron M; Reed, Lunde R; Cordova, Elsa A

Single-pass flow-through (SPFT) experiments were conducted with aluminoborosilicate waste glasses to evaluate how changes in solution composition affect the dissolution rate (r) at 40°C and pH(23°C) = 9.0. The three prototypic low-activity waste (LAW) glasses; LAWE-1A, -95A, and -290A, used in these experiments span a wide range covering the expected processing composition of candidate immobilized low-activity waste (ILAW) glasses. Results suggest incongruent release of Al, B, Na, and Si at low flow-rate (q) to sample surface area (S) [log10 (q/S) < -8.9 (m s-1)] whereas congruent release was observed at high q/S [log10 (q/S) > -7.9 (m s-1)]. Dissolution rates increase from log10 (q/S) ≈ -9.3 to -8.0 (m s-1) and then become constant at log10 (q/S) > -7.9 (m s-1). Forward (maximum) dissolution rates, based on B release, are the same irrespective of glass composition, evident by the dissolution rates being within the experimental error of one another (r1A = 0.0301 ±0.0153 g m-2 d-1, r95A = 0.0248 ±0.0125 g m-2 d-1, and r290A = 0.0389 ±0.0197 g m-2 d-1). Finally these results support the use of a chemical affinity based rate law to describe glass dissolution as a function of solution composition.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 925479
• Report Number(s): PNNL-SA-55565; 14592; 830403000
• Journal Information: Environmental Chemistry, 5(1):73-85, Journal Name: Environmental Chemistry, 5(1):73-85 Journal Issue: 1 Vol. 5
• Country of Publication: United States
• Language: English

Related Subjects

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
36 MATERIALS SCIENCE
ALUMINIUM OXIDES
BOROSILICATE GLASS
DISSOLUTION
Environmental Molecular Sciences Laboratory
KINETICS
LOW-LEVEL RADIOACTIVE WASTES
Low activity Waste
WASTE FORMS
chemical affinity
glass dissolution
transition state theory