Oxygen gradient

Definition

The variation in dissolved oxygen from the oxygen-rich outer biofilm to the oxygen-depleted metal interface.

Microbial respiration consumes oxygen with depth so that the base of the film can become fully anaerobic. This gradient enables anaerobic organisms such as sulfate-reducing bacteria to thrive at the metal surface and drives the oxygen differential corrosion cell. It is invisible to bulk water testing, which measures oxygen in the pipe rather than at the surface.

Related concepts

Mature community · Oxygen Differential Cell · Sulfate-reducing bacteria (SRB)

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Part of The Blueprint of Water · 🧪 chemistry