Patent ID: 8298422

Claim:
A method for the treatment of effluents containing nitrogen in the form of ammonium, using a sequencing batch reactor ( 1 ), according to which: a volume of effluent to be treated in a complete cycle is introduced into the batch reactor in successive volume fractions, each volume fraction being treated during a subcycle, the successive introduction of the volume fractions making it possible to exert a bacterial selection pressure favorable to the development and to the activity of nitriting bacteria by means of ammoniacal single-shots, each subcycle comprises a phase of feeding with a volume fraction and, in an alternating manner, two treatment stages, i.e.: an aerated first stage, during which complete or partial oxidation of the ammonium so as to give nitrites takes place, followed by a nonaerated second stage, under anoxic conditions, during which the nitrites produced and the ammonium are converted to nitrogen gas, wherein: during the aerated first stage, the dissolved oxygen concentration in the batch reactor is maintained between 0.1 mgO 2 /l and 0.6 mgO 2 /l, the N—NO 2 :N—NH 4 ratio is adjusted so as to be between 0.9 and 1.5 at the beginning of the nonaerated stage, and the nonaerated stage is carried out by deammonification, without the provision of a carbon-based substrate.