anoxic zone

anoxic zone

[a′nak·sik ‚zōn]
(oceanography)
An oxygen-depleted region in a marine environment.
References in periodicals archive ?
The stabilization reactor was a unique unit with different compartments that could be described as follows: i) SR: an aerated zone of suspended growth with a high presence of organic carbon; ii) SR an anoxic zone which favored denitrification; iii) SR an attached-suspended growth zone which favored nitrification and denitrification; and finally, iv) SR, an additional aerated zone of suspended growth with a high ammonia concentrations measured as total ammonia nitrogen (TAN) for favored nitrification.
Since the air-diffuser position resulted in the formation of aerobic or anoxic zone, the performance of nitrogen removal through SND might be compared to the separated reactions of nitrification and denitrification.
They identified big differences between infected tissue and tissue in the preliminary stage of the disease: "In diseased coral tissue two zones develop: A phototrophic zone at the top in which the cyanobacteria produce oxygen and a lower anoxic zone in which the bacteria degrade the necrotic coral tissue.
The oxygen is only found in the top layer, the oxic zone while the hydrogen sulfide is concentrated mostly in the bottom layer, the anoxic zone. The hydrogen sulfide and oxygen are kept separate through a series of redox reactions.
Even though there is no nitrate limit for this system, an anoxic zone was incorporated in the process in order to recover some of the alkalinity consumed by nitrification.
The microorganisms that live in some sediments off the coast of Louisiana provide a good record of the anoxic zone created by the Mississippi River, says Osterman.
An anoxic zone would precede the aerobic MBR to provide denitrification required by the TMDLs.
The first two-thirds of the anoxic zone at the head of pass No.
Scope : Retrofitting two of the existing four primary clarifiers to an anoxic zone and introduction of an internal recirculation pumping system for return of nitrifying bacteria to the anoxic zone and ancillary
The Vladix system combines multiple-stage settling chambers with an aeration basin providing high solids removal efficiency; the second stage of settling can be used as an anoxic zone for denitrification.
Denitrification occurs in an anoxic zone of zero dissolved oxygen ahead of the aerobic zone.