Abstract: The invention aims at enabling, in a catalytic decarbonation apparatus, inert particles coated with calcium carbonate to be constantly and systematically extracted from the reactor, with no risk of clogging the discharge pipes. Therefor, said pipes (7?a, 7?b) have an inside diameter ranging between 40 and 60 mm and they have a downward incline up to their connection to an outside discharge conduit (8?), except, possibly, a horizontal portion starting from the orifice through which they emerge into the reactor (1?).

Abstract: A method for reducing the amount of wastewater treatment station sludge first performs wastewater purification with fixed biological cultures from which excess sludge is extracted intermittently during phases of washing and unclogging. Then, the water from the washing phase that provides fixed biological cultures is subjected to biological activated sludge treatment, the outlet of this stage does not recycle effluent to the front end of the water treatment line. The wastewater is then subjected to a stage of reduced sludge production (RPB), selectively, by thermophilic enzymatic action or by partial oxidation by ozone introduced by mechanical stirring, this stage being supplied by quantities of sludge from the step of biological treatment by activate sludge, the substrate source for the bacteria of the biological treatment including organic material derived from lysed bacterial cells induced during the RSP stage.

Abstract: The invention concerns a device comprising a rotary shaft (2) supported above a layer (C) of material, transversely to the translation direction (A) of the material, and means for turning (3) the material extending at least partly radially relative to the shaft (2) and rotated by said shaft to penetrate into the layer. The device comprises means for cutting (4) the layer (C) of material, radially spaced apart (g) from the rotary shaft (2) and rotated by said shaft, said cutting means (4) being located substantially on a cylindrical surface sharing a common geometrical axis with the rotary shaft, and capable, upon penetration into the layer, of fragmenting the latter, while the turning means causes the fragmented material to be granulated.

Abstract: Systems and methods of treating flue gas and wastewater generated by treating the flue gas are disclosed and include introducing the flue gas, a flue gas treatment fluid that removes sulfur dioxide from the flue gas; and an organic acid conditioning agent into a wet-oxidation scrubber/absorber; introducing FGD scrubber wastewater generated by the wet-oxidation scrubber/absorber into an anoxic biological reactor to substantially denitrify the FGD scrubber wastewater; and introducing resulting substantially denitrified FGD scrubber wastewater into an anaerobic biological reactor to substantially reduce the amount of sulfate and/or selected heavy metals in the FGD scrubber wastewater.

Abstract: The invention relates to a method for the biological treatment of effluents contaminated with impurities of urban or industrial origin, characterised in employing a single aeration tank (1) with a high mass charge in which the raw effluent or mechanically pre-treated effluent is mixed without previous decantation with a free microbial culture of the activated sludge type, growing in a lightly aerated medium, of the order of 0.1 to 0.2 kg O2/kg BOD5 removed, the organic charge applied having a value equal to or greater than at least 2 kg COD/kgSM/day, preferably equal to or greater than 4 kg COD/kgSM/day, the hydraulic residence time for the raw effluent in the single aeration tank being between 30 and 90 minutes, preferably between 40 and 60 minutes.

Abstract: The invention relates to a method of cleaning membrane filters comprising hollow fibres and an inner skin. The inventive method comprises the following steps consisting in: emptying the concentrate compartment in order to release the liquid to be filtered contained therein and the suspended matter, and, subsequently, performing a backwashing step involving the passage of liquid from the permeate compartment into the concentrate compartment through membranes in order to detach and release impurities deposited thereon, while circulating a gas in the concentrate. According to the invention, backwashing liquid and/or gas pulses are produced by control means (5, 5a; 7, 7a) during at least one backwashing phase.

Abstract: The system dries pasty or powdery products such as sludge from wastewater purifying stations, the drying occurring in a chamber receiving the products to be dried. The system includes a greenhouse with translucent or transparent walls erected on a slab upon which a bed of products to be dried is deposited. At least one wind generator is provided for generating energy which is converted to heat that is delivered to the slab upon which the bed of products to be dried is spread.

Abstract: The invention relates to an installation for treating water by flotation, said installation comprising flotation equipment consisting of a flotation cell (10) into which flocculated raw water mixed with micro-bubbles produced by a pressurization-depressurization system (11) is guided, said cell being provided with a perforated collection device (13) designed in such a way that the surface of the flotation cell is crossed by an identical and uniform flow of water to be treated. The inventive installation is characterised in that it comprises capture modules (14) which are arranged in the flotation cell in such a way that the lower part thereof is located at a distance (h) from the perforated collection device (13), said distance being determined such that any disturbance of the uniform distribution established by the perforated collection device is avoided.

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 invention is directed to a system for removing waste material from a fluid flowing in a channel. This system may incorporate the use of a trap for collecting the waste material while allowing the fluid to pass; a rake for removing the waste material away from the trap; a drive assembly for moving the rake to remove the waste material; a prime mover for operate the drive assembly; and a variable speed controller configured for operating the prime mover over a variable range of speeds.

Abstract: The invention relates to a method for treating fluids, in particular waste waters involving coagulation/flocculation, clarification by filtration or flotation stages and a stage of filtration through micro-, ultra, and nanomembranes or of hyperfiltration. The inventive method consists in injecting two times several coagulating reagents in a quantity ranging from 75 to 125% of an optimal coagulation dose or a dose cancelling a Zeta potential (pz) in an area (area n° 1) situated upstream of the clarification stage (2) and from 0.1 to 25% of an optimal dose cancelling the pz in a second area (area n° 2) situated upstream of the stage of membrane filtration (4).

Abstract: A device for drying sludge originating in a waste water treatment plant is enclosed in a greenhouse having a floor for receiving a bed of sludge to be dried. The greenhouse employs solar energy. A spreader located in the greenhouse ensures the the sludge is spread over the floor and turned as it progresses along the drying device. Fans are positioned over the spreader to provide for the renewal of air present in said greenhouse. A controller controls start up and shut down of a drying cycle as well as automatic control of all motorized components in response to measurement of the temperature of the surface of the bed of sludge. The controller also takes into account the difference in temperature between the surface of the bed of sludge to be dried and the atmosphere present in the drying plant, equipment in the greenhouse only being started up when this temperature difference reaches a predetermined set point.

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 is directed to a system for removing waste material from a fluid flowing in a channel. This system may incorporate the use of a trap for collecting the waste material while allowing the fluid to pass; a rake for removing the waste material away from the trap; a drive assembly for moving the rake to remove the waste material; a prime mover for operating the drive assembly; and a variable speed controller configured for operating the prime mover over a variable range of speeds.

Abstract: A method for treating waste water uses a membrane bioreactor that produces excess biological sludge and treated water components. This is achieved by extracting the biological sludge from the bioreactor then causing contact between the biological sludge and dewatered effluent to form two resulting products. The first product contains polyclectrolyte loaded sludge. Polyelectrolyte is continually added to the polyelectrolyte loaded sludge during dewatering to separately form dewatered sludge and the dewatered effluent. This is followed by extracting, as a second product, polyelectrolyte free effluent. The polyelectrolyte free effluent is recycled to the bioreactor.

Abstract: An apparatus for irradiating fluids with UV including a reactor vessel (10) having a fluid inleT (12), a fluid outlet (14) and a reaction chamber (16); a plurality of UV lamps (18a–d) extending across the reaction chamber (16) and substantially perpendicularly to an axis (A) extending between the fluid inlet (12) and the fluid outlet (14); an upper fluid diverter (22) and a lower fluid diverter (24) extending across the reaction chamber (16) substantially parallel to the lamps (19a–d) and positioned downstream of at least one upstream UV lamp (18a, b), wherein the upper and lower fluid diverters (22, 24) are positioned to direct fluids toward at least one UV lamp (18c, d) downstream of the upstream UV lamp (18a, b).

Abstract: The invention is directed to a filter underdrain for supporting a filter media between at least two dividers forming at least one cell, which includes at least one porous plate for supporting the filter media for filtering a fluid, the porous plate spanning across at least one of the dividers; and a plurality of support members beneath the porous plate, the support members containing at least one port for draining the fluid after the fluid passes through the porous plate. The porous plates may be bound together by a lap joint and an end section may be included between at least two of the support members, the end section containing at least one pocket for holding the porous plate.

Abstract: The invention relates to a method for the biological treatment of effluents contaminated with impurities of urban or industrial origin, characterised in employing a single aeration tank (1) with a high mass charge in which the raw effluent or mechanically pre-treated effluent is mixed without previous decantation with a free microbial culture of the activated sludge type, growing in a lightly aerated medium, of the order of 0.1 to 0.2 kg O2/kg BOD5 removed, the organic charge applied having a value equal to or greater than at least 2 kg COD/kgSM/day, preferably equal to or greater than 4 kg COD/kgSM/day, the hydraulic residence time for the raw effluent in the single aeration tank being between 30 and 90 minutes, preferably between 40 and 60 minutes.

Abstract: A method of treating liquid including mixing coagulant with the liquid, introducing mixed coagulant and liquid into a primary reaction zone, containing an agitator, of a reactor which is substantially concentrically positioned with respect to a secondary reaction zone of the reactor, introducing flocculant into the primary reaction zone at a location between the agitator and where the mixed coagulant and liquid are introduced into the primary reaction zone, mixing the mixed coagulant and liquid with the flocculant and causing the resulting mixture to flow into the secondary reaction zone, introducing an encapsulating agent into the secondary reaction zone, recirculating the liquid and encapsulated flocs through the primary and secondary reaction zone, and passing the liquid and encapsulated flocs outwardly of the reactor, and an apparatus for treating liquids including a reactor, a draft tube substantially concentrically positioned within the reactor and being positioned such that the liquids may flow inwardl