Abstract: Coagulation/flocculation apparatus for the treatment of a hydraulic flow of any type of liquid, upstream of a physical separation element, in particular upstream of a flotation unit, or of a filtration unit, in particular a membrane filtration unit, which apparatus comprises at least one coagulator with injection of coagulant, followed by a flocculator, which are successively passed through by the hydraulic flow, in which apparatus: the coagulator comprises a reactor (1) for injection of coagulant under high energy, followed by a low-energy coagulation reactor (2); an intermediate high-energy element (3) is placed between the coagulation reactor (2) and the flocculator (4); and the flocculator is a static flocculator of piston type (4) having the same width as the physical separation element (5) located downstream.

Abstract: The invention relates to a rapid flotation device, in particular using dissolved air, for treating water laden with suspended matter (MES). The device comprises a mixing area (B) separated from a flotation area (C) by a wall (n) above which the liquid to be treated passes from the mixing area. The bottom portion of the flotation area comprises: a perforated floor (1) located above an apron (R), a floated-water discharge being provided under the floor and leading to an outlet system (3); and at least two separate channels (2) which are oriented in the direction of flow of the water and are provided under the floor (1), and under optional structures (w) extending from the floor, to a point upstream of the outlet system (3). The downstream end (2.1) of the channels is open and located above the floor level, and a discharge means (V) is provided, for each channel, at the end of the downstream bottom portion of said channel.

Abstract: The invention relates to a rapid flotation device, in particular using dissolved air, for treating water laden with suspended matter (MES). The device comprises a mixing area (B) separated from a flotation area (C) by a wall (n) above which the liquid to be treated passes from the mixing area. The bottom portion of the flotation area comprises: a perforated floor (1) located above an apron (R), a floated-water discharge being provided under the floor and leading to an outlet system (3); and at least two separate channels (2) which are oriented in the direction of flow of the water and are provided under the floor (1), and under optional structures (w) extending from the floor, to a point upstream of the outlet system (3). The downstream end (2.1) of the channels is open and located above the floor level, and a discharge means (V) is provided, for each channel, at the end of the downstream bottom portion of said channel.

Abstract: Coagulation/flocculation apparatus for the treatment of a hydraulic flow of any type of liquid, upstream of a physical separation element, in particular upstream of a flotation unit, or of a filtration unit, in particular a membrane filtration unit, which apparatus comprises at least one coagulator with injection of coagulant, followed by a flocculator, which are successively passed through by the hydraulic flow, in which apparatus: the coagulator comprises a reactor (1) for injection of coagulant under high energy, followed by a low-energy coagulation reactor (2); an intermediate high-energy element (3) is placed between the coagulation reactor (2) and the flocculator (4); and the flocculator is a static flocculator of piston type (4) having the same width as the physical separation element (5) located downstream.

Abstract: The invention relates to a method for the floatation-clarification of difficult water, in particular heavily polluted surface water, urban or industrial wastewater, rainwater or any type of water that floats with difficulty, particularly water which contains a high percentage of mineral matter or requires the injection of a flocculation aid and which originates from filters or membrane technologies such as ultrafiltration, said method comprising: a coagulation step (A1) in which a dose of coagulant (1) is injected into the water to be treated; a flocculation step (B) in which flocculant (2) is injected (B1) into the water after the coagulation step, in order to agglomerate the suspended particles in the form of flocs; and subsequently a floatation step (C) in which the flocculated water is mixed with an emulsion of air micro-bubbles in a floatation apparatus. A second coagulant injection step (A2) is performed downstream of the flocculant injection (B1) and upstream of the floatation (C).

Abstract: Sequential biological reactor (R), comprising: a tank (1) delimited by a base and peripheral walls (3); an inlet (11) equipped with a selector (S) that determines a baffled route with contacting of the effluent to be treated and a portion (5) of the recirculated sludges; a means (6) for discharging the treated water in the top part of the water surface of the tank, and an outlet (7) for discharging the excess sludges in the bottom of the tank. The selector (S) comprises a vessel (8) placed in the tank (1) at a distance from the peripheral walls (3); the vessel is compartmentalized into several sectors (8.1, 8.2, 8.3, 8.

Abstract: The invention relates to a method for the floatation-clarification of difficult water, in particular heavily polluted surface water, urban or industrial wastewater, rainwater or any type of water that floats with difficulty, particularly water which contains a high percentage of mineral matter or requires the injection of a flocculation aid and which originates from filters or membrane technologies such as ultrafiltration, said method comprising: a coagulation step (A1) in which a dose of coagulant (1) is injected into the water to be treated; a flocculation step (B) in which flocculant (2) is injected (B1) into the water after the coagulation step, in order to agglomerate the suspended particles in the form of flocs; and subsequently a floatation step (C) in which the flocculated water is mixed with an emulsion of air micro-bubbles in a floatation apparatus. A second coagulant injection step (A2) is performed downstream of the flocculant injection (B1) and upstream of the floatation (C).

Abstract: The inventive nozzle comprises a first releasing stage (1) for producing a pre-release by absorbing from 5 to 20% of available pressure, a second releasing stage (2) wherein a substantial release is carried out and the pressurised water passes from a saturation pressure to an output nozzle pressure, an intermediate chamber (3) in the form of a transition chamber in which the pressurised water approaches the saturation pressure by absorbing from 5 to 30% of the available pressure and an outlet tube (3) consisting of a sudden release and cavitation confinement tube whose minimum length (1) substantially corresponds to a distance separating the end of said tube on the second release stage side from a readhesion point of jets to the tube wall at the angle of divergence (alpha) thereof ranging from 3 to 12 DEG before readhesion.

Abstract: The inventive nozzle comprises a first releasing stage (1) for producing a pre-release by absorbing from 5 to 20% of available pressure, a second releasing stage (2) wherein a substantial release is carried out and the pressurised water passes from a saturation pressure to an output nozzle pressure, an intermediate chamber (3) in the form of a transition chamber in which the pressurised water approaches the saturation pressure by absorbing from 5 to 30% of the available pressure and an outlet tube (3) consisting of a sudden release and cavitation confinement tube whose minimum length (1) substantially corresponds to a distance separating the end of said tube on the second release stage side from a readhesion point of jets to the tube wall at the angle of divergence (alpha) thereof ranging from 3 to 12 DEG before readhesion

Abstract: The inventive nozzle comprises a first releasing stage (1) for producing a pre-release by absorbing from 5 to 20% of available pressure, a second releasing stage (2) wherein a substantial release is carried out and the pressurised water passes from a saturation pressure to an output nozzle pressure, an intermediate chamber (3) in the form of a transition chamber in which the pressurised water approaches the saturation pressure by absorbing from 5 to 30% of the available pressure and an outlet tube (3) consisting of a sudden release and cavitation confinement tube whose minimum length (1) substantially corresponds to a distance separating the end of said tube on the second release stage side from a readhesion point of jets to the tube wall at the angle of divergence (alpha) thereof ranging from 3 to 12 DEG before readhesion.

Abstract: A method is disclosed for clarifying, by flotation, waters contaminated with suspended matter, wherein the clarification treatment takes place in two successive steps implemented in a single installation. The method principally involves flowing contaminated water through a downflow static flocculation step and then down through a lamellar settler separation step positioned directly below the downflow static flocculation step, the settling rates of the heavier particles of the lamellar settler separation step removing heavier particles from the water retained during the static flocculation/lamellar separation step being less than or equal to the settling rates of the floatable particles. The water which has passed through the static flocculation/lamellar settler separation step is then subjected to a flotation step which removes the light particles in the water of which the settling rate is lower than a flotation cutoff threshold.

Abstract: A water purification installation includes a coagulation area, a flocculation area, an area for mixing, in an upflow, the flocculated water with pressurised water which is delivered by a microbubble-generating pressurisation-pressure reduction system, and a flotation area. Suspended matter, which is brought to the surface by the microbubbles, is evacuated from the upper part of the flotation area. Moreover, the lower part of said flotation area includes means of collecting the clarified water. The geometry of the flotation area is such that the ratio between the height (H) of the area located above the clarified water collection means and the length (L) of the area is between 0.3 and 1; and the ratio between the surface (Sa) of the nappe at the outlet of the mixing area and the surface (Sp) of the actual flotation area is between 0.05 and 0.5 and, preferably, between 0.1 and 0.35.

Abstract: The invention relates to a method for clarification by flotation of water loaded with material in suspension, characterised in that the clarification treatment is carried out in two successive stages in a single plant. The method comprises a static flocculation step with descending current, integrated with a primary separation step for the heaviest particles, the zone in which the primary separation of the heaviest particles occurs being situated beneath the zone in which the static flocculation step is carried out and comprises a removal of the heaviest particles and a flotation step which guarantees the removal of the light particles, the decantation speed of which is below the threshold for cleaving the flotation agent.

Abstract: A water purification installation includes a coagulation area, a flocculation area, an area for mixing, in an upflow, the flocculated water with pressurised water which is delivered by a microbubble-generating pressurisation-pressure reduction system, and a flotation area. Suspended matter, which is brought to the surface by the microbubbles, is evacuated from the upper part of the flotation area. Moreover, the lower part of said flotation area includes means of collecting the clarified water. The geometry of the flotation area is such that the ratio between the height (H) of the area located above the clarified water collection means and the length (L) of the area is between 0.3 and 1; and the ratio between the surface (Sa) of the nappe at the outlet of the mixing area and the surface (Sp) of the actual flotation area is between 0.05 and 0.5 and, preferably, between 0.1 and 0.35.

Abstract: Process employing the technique of ballasted flocculation with a step of injection, into the liquid to be clarified, of a ballast consisting of a granular material and of a polymer, followed by a flocculation step which leads to the formation of a ballasted floc, and by an accelerated settling step, said ballast being recirculated into the flocculation step, either as it is or after cleaning, wherein said process includes two recirculation regimes: a high-energy regime ensuring draw-off of the ballast contained in the ballasted floc, removal of the floc in the form of sludge and recycling of the cleaned ballast into the flocculation unit and, a low-energy regime ensuring transfer of the ballasted floc into the flocculation unit as long as the ballast ratio in the flocculator is greater than a predetermined level, this low-energy regime remaining in service while the high-energy regime is being put into action, but then being shut down during the operation of the high-energy regime, the two systems being emp

Abstract: Process for the physico-chemical treatment of effluent, especially of surface water intended for consumption, comprising the successive steps of coagulation, flocculation and settling, a contacting mass being introduced into the water coming from the coagulation step, and therefore during the flocculation step, and this contacting mass consisting of part of the densified sludge resulting from the settling step and recycled in the flocculation step, this process being characterized in that at least part of the polyelectrolyte ensuring flocculation is injected into a sludge-recirculation circuit.

Abstract: A process is disclosed for the physico-chemical treatment of effluent, especially surface water intended for consumption, the process includes the successive steps of coagulation, flocculation and settling, wherein, during the flocculation step, a ballast is introduced into the sludge, the function of which ballast is to make the sludge heavier. The contacting mass used during this flocculation step consists of part of the densified sludge resulting from the settling step and continuously recycled in the flocculation step, without any treatment.

Abstract: Water treatment plant having pretreatment means, such as in particular means of desanding, degreasing, physico-chemical pretreatment such as coagulation and flocculation and biological pretreatment, as well as means of separating the solid particles contained in the untreated water, characterized in that the solid/liquid separation means are contained within a construction of circular shape, and the untreated-water supply means as well as at least one of the pretreatment means are incorporated in a structure in the shape of an isosceles trapezoid whose projected apex lies on a diametral axis of the construction of circular shape containing the separation means, whose sides are formed by the two tangents to the circular construction leading from the said projected apex and whose base is tangent to the circular construction at the point of intersection of this construction with the diametral axis.

Abstract: A mixed culture reactor biologically removes organic pollution and nitrates by the anoxic route. The reactor includes a central stirred section having a lower part in which biological treatment of supplied raw water takes place. The central reactor section contains a suspension of an attached biomass of low concentration, in the order of a few grams per liter. At least one propelling screw is 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 circulates in one direction within the jacket and in an opposite direction outside the jacket. The speed of circulation is selected so that bioparticles remain in suspension within the reactor central section. A release zone is located externally of the reactor central section and communicates with a lower part thereof.

Abstract: Device for treating waste water, especially rainwater by jointly carrying out degritting, degreasing and settling, which includes a degritter fitted with a grit trough, passed through by a descending then ascending flow of the water to be treated, a degreasing surface provided above a part of the degritter and the feed region of the settling tank, and a settling tank which includes a feed or presettling basin, a floor, a laminar settling region and an extraction trough, wherein the partition separating the degritter from the settling tank includes a flap valve making it possible, when it is open, to transfer the untreated water without perturbation towards the settling tank, and therefore allowing correct settling during this filling phase.