Method for treating a wastewater effluent in a sequencing batch reactor (sbr) having a constant level and controlled recovery

Abstract

An installation for treating a wastewater effluent in a constant-level sequencing batch reactor (SBR), the SBR includes a chamber that is able to contain a mixture of wastewater and sludge comprising different levels, each level being defined by a concentration and/or a density of sludge, a sludge bed situated at the bottom of the chamber, a device for supplying the SBR with a volume of effluent to be treated close to the bottom of the chamber, in the sludge bed, preferably via a distribution network covering the bottom of the chamber, means for recovering a clarified fraction of the contents of the chamber, the SBR being able to implement a treatment method comprising a biological treatment reaction sequence comprising at least a step of aerating the contents of the chamber, during which the level of the surface of the mixture rises, a decanting step, during which sludge is deposited on the bottom of the chamber and the contents of the chamber are clarified close to the surface thereof, a step of recovering the clarified fraction of the contents of the chamber, the recovery step and supply step taking place simultaneously, so as to keep the level of the contents of the chamber substantially constant during the recovery step and supply step, the installation also comprising control means and recovery means.