Biological phosphorous and nitrogen removal (BNR) from municipal and industrial waste waters now became popular technology. It is cost-effective and environmentally friendly method to reduce phosphorous, nitrogen and organic discharge. BNR one of the best ways to reach Russian strike requirements for nitrogen (0.5 mg/l N-NH₄ and 9.5 mg/l N-NO₃) and phosphorous (1 mg P/l) concentrations in treated wastewater.

In this process, polyphosphate accumulated microorganisms (PAO) passes through anaerobic, anoxic and aerobic conditions. In anaerobic conditions, PAO uptake rapid biodegradable organic COD (RBCOD), firstly volatile fatty acids (VFA), and storage them as polyhydroxyalkanoates (PHA). Energy for this process produced by polyphosphate hydrolysis. In the same time, in anaerobic conditions take place hydrolysis and acidification of another forms of organic COD presenting in wastewater. In anoxic conditions, PAO, which can use NO^3- as electron acceptor (denitrification process), oxidize PHA for growth and uptake phosphorous from liquid phase with polyphosphate formation. Heterotrophs can used hydrolyzed in anaerobic condition organic COD for denitrification. In aerobic conditions, PHA oxidation, growth and phosphorous uptake proceed using oxygen. In the same time, nitrification and COD oxidation take place.
We can design this process for wastewater flows from 10 till 500,000 m³/day (new block at Luberetzkaya wastewater treatment station) using continuos flow carousel aeration tanks, sequenced batch reactors (SBR) or sequenced batch bed reactors (SBBR). Also this technology allows a tremendous reduction of energy consumption and waste sludge production if anoxic dephosphatation is used.

Contact person:

Dr. S.V.Kalyuzhnyi, Dept. of Chem. Enzymology, Chemistry Faculty., Moscow State University, 119899

Moscow, Russia; Phone: 7-(095)-9395083; Fax: 7-(095)-9395417; email: svk@enz.chem.msu.ru