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UDC 628.35:661.63

KOZLOV M. N., Kevbrina M. V., Nikolaev Yu. A., Dorofeev A. G., GRACHEV V. A., KAZAKOVA E. A., Aseyeva V. G., Zharkov A. V.

Single-reactor technology of nitrogen removal from wastewater

Summary

The experts of R&D Centre of «Mosvodokanal» OJSC developed high-effective technology of removing nitrogen from wastewater. The technology was tested at the Kur’ianovo wastewater treatment plant of the city of Moscow during processing filtrate of the digested sludge belt thickeners. The method is based on the use of specific Anammox-bacteria that oxidize ammonium with nitrite under anoxic conditions. Filtrate is processed in a sequencing batch reactor with complete mixing (SBR-reactor). Partial nitrification processes (ammonium oxidation into nitrite), ammonium oxidation with nitrite and organic matter oxidation are carried out in one reactor. Retention of extremely slow growing biomass of Anammox-bacteria has been a critical problem for all the reactors. In this particular case the problem was solved with bacteria adhesion on the reactor walls and the feed as well as with flotation. To evaluate the treatment efficiency standard methods were used. The developed single-reactor modification of the anoxic oxidation of ammonium differs from the well-known by the following parameters: high nitrogen removal efficiency, the method of biomass bacteria retention in the reactor, the availability of new Anammox bacteria, heterotrophic denitrification. All other conditions being equal the integration of Anammox single-reactor technology requires the size of the facilities ten times smaller than double-reactor technology; for this reason it is more preferable for implementation. The new technology was given the name AUTOHETAMMOX.

Key words

wastewater , nitrogen removal , bioreactor , nitrification-denitrification , anammox bacteria