Glass dissolution rates from static and flow-through tests.

We measured the dissolution rate of a simple five-component glass at 70 C using static tests and single-pass flowthrough (SPFT) tests with pH buffers at pH values of 6.2, 8.3, and 9.6. The two methods yielded similar rates; however, the measured rates are about 10X higher than the rates measured previously for a glass having the same composition using an SPFT test method. Differences are attributed to how the effect of the solution flow rate on the glass dissolution rate was taken into account and how the surface area of crushed glass was estimated. The differences indicate the need to standardize the SPFT test procedure