Patent ID: 6024876
Filing Date: 2000-02-15
Classification: C02F,Y02W,Y10S

Abstract:
A mixed culture reactor for biologically removing organic pollution and nitrates by the anoxic route and comprising:a central stirred section having a lower part in which biological treatment of supplied raw water takes place;the central reactor section containing a suspension of an attached biomass of low concentration, in the order of a few grams per liter;at least one propelling screw positioned within a jacket that is coaxially located in the reactor central section to ensure the circulation of the water to be treated;the water to be treated circulating in one direction within the jacket and in an opposite direction outside the jacket;the speed of circulation selected so that bioparticles remain in suspension within the reactor central section;a release zone located externally of the reactor central section and communicating with a lower part thereof;the water treated within the reactor central section escaping through the release zone, to the upper part of the central section, in accordance with an ascending current, whereby the current has a speed such that the decantation speed of the bioparticles is greater than the speed of the water, and the speed of decantation of the excess biomass produced by biological reactions is less than the speed of the water; andmeans for enlarging a reactive zone at the lower part of the release zone.