PH-Buffering Effects of the CO sub 2 -CO sub 3(2-) System in Deep Groundwaters

摘要

Equilibria in the system H sub 2 O-CO sub 2 -CaCO sub 3 (s) are discussed, and data from some deep granitic groundwaters are summarized. For most waters pH would be in the range 7-9 and the total carbonate concentration in the range 30-400 mg/l (more often 90-275 mg/l). The observed field data represent reasonably well closed water systems with fixed total carbonate concentrations. The carbonate concentration (CO sub 32- ) can be estimated from log (CO sub 32- ) = 0.76pH-10.83+0.08, which would represent about 50% of all the observed concentration/pH-data (for the waters with the highest carbonate concentrations). (Atomindex citation 14:788679)