Figure 2.

In-situ O₂ and pH microprofiles in cyanobacterial biofilms from aerated and non-aerated Fe²⁺-rich and aerated Fe²⁺-poor reactors. All profiles were measured under similar irradiance as that used during long-term incubations of the reactors. Measurements in the biofilm from the aerated Fe²⁺-poor reactor were conducted outside of the reactor using the natural water purged with N₂ gas to maintain anoxic conditions.