[OLD] Dissolved oxygen

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From: Finch, Robert J.

Subject: Dissolved oxygen

We are conducting experiments in which we oxidize uraninite (UO2) in dripping groundwater and humid air. We have two types of experiment:

(1) low-volume "flow-through" experiments, in which we periodically inject small volumes of water and fresh air into sealed vessels, some of which are vented before each injection (the injected water collects within each vessel), and

(2) batch experiments, in which solids and water are placed into sealed vessels for various fixed time periods.

We are a little concerned that these experiments might become depleted in oxygen (especially the vented vessels), thereby slowing/inhibiting the oxidation reaction(s) that we are trying to study (some experiments run for a year or more between being opened). We don't have convincing evidence from the experiments that this is true; however, some back-of-the-envelop calculations suggest that oxygen depletion might be a problem. Can I use Geochemists' Workbench to model the partial pressure of O2 in the vessels and the dissolved concentration of O2 in the water as a function of temperature (and maybe time) for the various experimental conditions? I am unsure how to approach this from my rather limited experience with GWB.