anoxic zone

anoxic zone

[a′nak·sik ‚zōn]
(oceanography)
An oxygen-depleted region in a marine environment.
References in periodicals archive ?
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.
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.
A perched water table exists as a zone of near saturation and is characterized by a large volume of water-filled pores that could create an anoxic zone containing little or no [O.
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
has the Bio-Nutri[TM] system that uses flow equalization and aeration, chemical precipitation, and an anoxic zone for nitrogen and phosphorus removal.
Denitrification occurs in an anoxic zone of zero dissolved oxygen ahead of the aerobic zone.