Randy Holmes-Farley
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My Tank Thread
But if you continue to pump gas (ozone) in, then gas has to exit the closed system somewhere, or else it would continue to build up, right? Unless by recirculating, 100% of the gas introduced completely dissolves into the water and exits with the water?
Ozone rapidly becomes not a gas once dissolved into seawater. It reacts with and quickly becomes other, reactive chemicals, such as hypobromite:
When ozone is applied in seawater in concentrations higher than are naturally present, a larger variety of chemical reactions take place. Chief among these is oxidation of bromide to hypobromite:6,7
O3 + Br- --> BrO- + O2
BrO- + H2O --> BrOH + OH-
The first reaction is very fast, and the half life of unreacted ozone in water with a lot of bromide (such as seawater) is on the order of a few seconds.8 Because hypobromous acid's pKa (in freshwater) is about 9, it is primarily in the protonated (uncharged form) in seawater, but a significant amount of BrO- is also present.3 The hypobromous acid is itself a strong oxidizer and can rapidly oxidize other organic or inorganic materials.4
The hypobromous acid can also react in a variety of ways (including disproportionation and additional oxidation with ozone) to form bromate:
BrOH --> --> --> BrO3-