Abstract: A reactor for the biological treatment of wastewater, includes a chamber capable of containing a mixture of wastewater and sludge comprising various levels, each level being defined by a sludge concentration and/or density; means for determining a minimum level and a maximum level of sludge extraction in the chamber, comprising: measurement means capable of measuring the sludge concentration and/or density at various levels of a mixture of wastewater and sludge; selection means capable of selecting a maximum sludge concentration and/or density value and a minimum sludge concentration and/or density value; deduction means capable of deducing a minimum extraction level corresponding to the maximum concentration value selected and a maximum extraction level corresponding to the minimum concentration value selected; extraction means capable of extracting sludge at variable levels between the minimum extraction level and the maximum extraction level.

Abstract: A reactor for the biological treatment of wastewater, includes a chamber capable of containing a mixture of wastewater and sludge comprising various levels, each level being defined by a sludge concentration and/or density; means for determining a minimum level and a maximum level of sludge extraction in the chamber, comprising: measurement means capable of measuring the sludge concentration and/or density at various levels of a mixture of wastewater and sludge; selection means capable of selecting a maximum sludge concentration and/or density value and a minimum sludge concentration and/or density value; deduction means capable of deducing a minimum extraction level corresponding to the maximum concentration value selected and a maximum extraction level corresponding to the minimum concentration value selected; extraction means capable of extracting sludge at variable levels between the minimum extraction level and the maximum extraction level.

Abstract: A method for treating effluents containing nitrogen in the form of ammonium, implementing chemical reactions for oxidizing and reducing the nitrogen in a sequencing batch reactor, the method including: introducing a volume of effluents to be treated into the reactor, injecting oxygen or air into the reactor for partial oxidation of the ammonium into nitrites and/or nitrates, interrupting the injection of oxygen or air, thus producing gaseous nitrogen, depositing the sludge at the bottom of the reactor and clarifying the content of the reactor close to the surface of same, discharging a clarified fraction of the content of the reactor. The draining and feeding steps occur simultaneously. During the feeding step, the volume of effluents is introduced close to the bottom of the reactor. During the draining step, the clarified fraction of the content of the reactor is discharged close to the surface of the content of the reactor.

Abstract: Disclosed is a process for the treatment of urban or industrial wastewater, in particular a process for the primary treatment of water, said process comprising a first operating mode P1 of the treatment system called a “reagent-free mode”, a second operating mode P2 of transition from the first reagent-free mode P1 to a third mode P3, said third operating mode P3 of the treatment system being called a “mode with reagents”, switching from the first mode P1 to the second mode P2, from the second mode P2 to the third mode P3 and from the third mode P3 to the mode P1 being respectively made after verifying a set of conditions C1, C2 and C3.

Abstract: A method for biologically denitrifying waste water, includes a nitrification-denitrification sequence followed, for a first fraction of water, by a post-denitrification step during which an electron donor is injected into the first fraction, while a second fraction of water passes through a bypass, then is mixed with the first fraction downstream of the post-denitrification step; the first fraction of waste water is subjected, during the post-denitrification, to a nearly complete denitrification so as to exit the step at a nitrate [N—NO3] concentration less than 4 mg/L, to minimize nitrous oxide production. The bypass rate is determined based on: a measurement of the nitrate concentration of the water upstream of the post-denitrification, the desired nitrate concentration for the mixture of the two fractions downstream of the post-denitrification treatment, and the nitrate concentration of the first fraction at the outlet of the post-denitrification, before the mixing of the two fractions.

Abstract: A method for treating effluents containing nitrogen in the form of ammonium, implementing chemical reactions for oxidizing and reducing the nitrogen in a sequencing batch reactor, the method including: introducing a volume of effluents to be treated into the reactor, injecting oxygen or air into the reactor for partial oxidation of the ammonium into nitrites and/or nitrates, interrupting the injection of oxygen or air, thus producing gaseous nitrogen, depositing the sludge at the bottom of the reactor and clarifying the content of the reactor close to the surface of same, discharging a clarified fraction of the content of the reactor. The draining and feeding steps occur simultaneously. During the feeding step, the volume of effluents is introduced close to the bottom of the reactor. During the draining step, the clarified fraction of the content of the reactor is discharged close to the surface of the content of the reactor.

Abstract: A method for biologically denitrifying waste water, includes a nitrification-denitrification sequence followed, for a first fraction of water, by a post-denitrification step during which an electron donor is injected into the first fraction, while a second fraction of water passes through a bypass, then is mixed with the first fraction downstream of the post-denitrification step; the first fraction of waste water is subjected, during the post-denitrification, to a nearly complete denitrification so as to exit the step at a nitrate [N—NO3] concentration less than 4 mg/L, to minimize nitrous oxide production. The bypass rate is determined based on: a measurement of the nitrate concentration of the water upstream of the post-denitrification, the desired nitrate concentration for the mixture of the two fractions downstream of the post-denitrification treatment, and the nitrate concentration of the first fraction at the outlet of the post-denitrification, before the mixing of the two fractions.

Abstract: A device for exciting a waveguide with circular polarization from a plane antenna, said waveguide (10) being a rectilinear hollow waveguide closed at one of its ends (12), said antenna being excited by at least two coaxial ports (13, 14) fed in phase quadrature by a circuit including a hybrid coupler (15), and being constituted by a radiating plane metal pattern (11) disposed on the surface of an insulating substrate (18) closing the waveguide (10) perpendicularly to its axis of symmetry.