NRP Report - CEE Cornell

When the D.O. drops down to near zero, the reactor is in the settle phase, when there is no aeration and the cells are using up all the remaining oxygen in the plant. When the D.O. level spikes up to over 7 or 8 mg/L, then the plant is in the drain phase, as the D.O. probe is exposed to the atmosphere, and is reading the oxygen level in the room. ................
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