Abstract: A process for nitrification, in the heterogeneous phase, of the flue gases produced by a combustion furnace (1), in particular a furnace for incinerating waste or sludge from a municipal water or industrial water purification plant, according to which the fuel is introduced into a fluidized bed (B) or onto a grate, and combustion air (2) is injected into the furnace; a reducing agent (6) is injected into the fuel and/or into the combustion air, upstream of the combustion chamber (H), and is mixed homogenously with the fuel and/or the combustion air, in order to carry out a reducing treatment promoted by the bed (3) of ash or of solids present in the furnace.

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 the forced dewatering, by pressing, of saline residues produced by drinking water production, or by the treatment of municipal or industrial wastewaters, in which method the saline residues are introduced into the cylinder (12a) of a piston press (12) comprising flexible drains (12e) formed by flexible sheaths from a material that is permeable to liquid but impermeable to solids, each drain (12e) comprising an inner passage that opens into an associated opening (12g), the press operating in batches, and characterized in that during pressing, the piston carries out reciprocal movements and applies alternating and variable pressures to the sludge, while the flexible drains are deformed, the liquid pressed out from the product passing through the wall of the drains and being discharged as a filtrate, while the dewatered sludge remains outside the drains and is discharged by opening the press.

Abstract: A method for biologically treating effluent involves pouring the effluent into a basin in which mobile supports are submerged for developing a biofilm and for carrying out a treatment by fixed fluidized bed, aerating the effluent in the basin with a distribution of air flow, from the bottom of the basin, according to a floor configuration, the aeration supplying air for treating the nutrients, and keeping the supports moving, regulating the aeration to modulate the air flow depending on at least one parameter taken from the following parameters: the residual oxygen concentration, and/or the concentration of oxygen and the concentration of N—NH4, and/or the permitted load; modifying the distribution of the air supply from the floor configuration to a spiral flow configuration when the operating conditions result in an air flow lower than a minimum air flow required to keep the mobile supports moving in the floor configuration.

Abstract: A method for conducting combustion in a fluidized bed furnace, in particular having a sand bed, according to which a flow of primary combustion air is blown through the bed, the fuel consisting in particular of organic waste, or of municipal waste, or of sludge from purifying stations, it being possible to inject secondary air (5a) into the space (5) in the furnace located above the bed; in order to limit the production of nitrogen oxides NOx and nitrous oxide N2O: the nitrous oxide N2O and nitrogen oxide NOx content of the fumes at the outlet of the furnace are measured (12, 20); the temperature of the fluidized bed is controlled to keep it at the highest admissible value at which the production of nitrous oxide N2O is substantially reduced, while the production of nitrogen oxides NOx is not substantially increased; and the excess air in the fluidized bed is controlled to keep it at the lowest admissible value at which the production of nitrogen oxides NOx is reduced without adversely affecting the combustio

Abstract: The invention relates to a method for ultra-dehydrating thickened or pasty biomass products, in particular sludge from wastewater treatment plants, according to which the products, in particular products having a dryness of 4% to 25%, are subjected to the following steps: hydrothermal carbonization treatment, including pressurization (1, 2) and thermal conditioning (30) for a duration in a closed reactor (4); followed by dehydration of the products by a ram press (12), obtaining a dryness of more than 50%; the temperature of the product upstream from the ram press dehydration being regulated by cooling between 40° C. and 90° C., advantageously to around 70° C., in order to optimize the filterability in the piston press; the steps of the method being performed in a confined space making it possible to prevent the release of smells into the atmosphere.

Abstract: The invention relates to a method for treating organic waste, in particular to a method for treating sludge from wastewater treatment plants, in order to produce power and/or hygienized organic matter, including a first step of mesophilic or thermophilic digestion (13) of at least one fraction of a stream of organic waste, and comprising the following steps: dehydrating (15) all of the digested and non-digested waste; aerated thermal hydrolysis (16) of the dehydrated waste, including an injection of an oxidizing agent in a quantity lower than the stoichiometric quantity for oxidizing organic matter, and setting to the required temperature by a heating means; and a second mesophilic or thermophilic digestion (17) of the stream of hydrolyzed waste.

Abstract: A process for reducing the production of sludge by municipal or industrial wastewater purification plants, comprising a step of mesophilic or thermophilic anaerobic digestion (20), or anaerobic digestion combining these two operating modes, of a stream of sludge to be treated (1), and at least one biological solubilization anaerobic treatment step (30); the process comprises, upstream of the anaerobic digestion step, a step of dehydration (10) of the sludge to be treated, followed by a step of mixing (15) the dehydrated sludge with a recirculated fraction of sludge that is more liquid, originating from recycling of the digestion (20), and/or from the anaerobic treatment step (30), and/or centrates originating from a final dehydration (50) of the treated sludge, wherein the recirculation rate is chosen such that the mixture has a dryness suitable for digestion, this mixture then being directed towards the digestion.

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 reverse-osmosis water desalination plant comprising: a reverse-osmosis membrane unit (TP); at least one high-pressure pump (HP); a pressure-exchange-type energy collector (SRE) capable of transferring pressure from the concentrate leaving the membrane unit to a portion of the water to be treated; sensors for various operating parameters, in particular pressure, flow rate, temperature and salinity level, said sensors being provided at suitable locations; and control loops so that the various adjustable elements are maintained at a setpoint value. The plant also includes a secondary control system (D) comprising calculation means (26) programmed to determine, on the basis of the operating conditions of the plant supplied by the sensors, a combination of setpoint values for the flow rate of the high-pressure pump, the mixing ratio of the energy collector and the conversion ratio, which combination minimizes the energy consumption of the high-pressure pump.

Abstract: The invention relates to a method for desulphuration of the digestate and biogas in a digester (1) of urban and/or agricultural and/or industrial effluent, by biochemical and/or thermochemical processes, the digester consisting of an enclosure (2) which is closed at the top, in which anaerobic digestion of a mass of products to be treated making up the digestate (4) takes place, the digester comprising at least one loop (10) for external recirculation of the digestate; an oxidant is injected at least at one point (13, 14) of the loop (10), the injection conditions being as follows: the speed of circulation of the digestate in the loop (10) must be high enough to prevent the deposition of sulphur on the walls of the pipes; the contact time between the injected oxidant and the recirculated digestate recirculated from the injection point (13, 14) of the oxidant until the reinjection point (11b) of the digestate must be long enough for all the oxidant to be dissolved in the liquid phase of the digestate; the amou

Abstract: The invention relates to a method for washing a filter (F) having at least two layers of filtering media (4, 5) for raw water containing components having a tendency to form cakes (M), in particular for seawater, the layers of filtering media being supported by a base (6) comprising pass-through openings and provided with nozzles (6a) enabling air and/or wash water to be injected, the raw water flowing through the layers from top to bottom and the treated water being recovered at the lower portion of the filter, and which comprises at least one spillway (D) at the upper portion thereof for collecting the wash water.

Abstract: Process for treating effluents containing nitrogen in ammonium form, using a sequential biological reactor (1), according to which: a volume of effluents to be treated in one complete cycle is introduced into the biological reactor in one or more successive fractions by volume, each fraction by volume being treated during a subcycle; each subcycle comprises a phase of feeding with a fraction by volume, and at least a first aerated step, during which total or partial oxidation of the ammonium to nitrites takes place by injection of air or of oxygen into the effluent, a settling out and emptying step taking place after the end of the complete cycle; the weight of N—NH4 to be treated is determined from the volume of effluents in the reactor at the end of the feeding phase, and from the difference between the initial N—NH4 concentration in the reactor and a concentration desired at the end of the aerated step, a maximum aeration time TM is dedicated to the aerated step, and an initial air flow rate Qairinit, for

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 static decanter (D) for prethickening liquid sludge in a water treatment plant, in particular wastewater, comprising an inclined bottom (8), the decanter being provided with a liquid sludge supply pump (13), a device for injecting a polymer in the liquid sludge, an overspill discharge (23) and a pump (26) for extracting the prethickened sludge from the decanter. The decanter further includes a means for accelerating the sludge decantation, a means (M) for adjusting the concentration of suspended material in the prethickened sludge at the outlet, and capable of maintaining the concentration of the prethickened sludge extracted from the decanter at a substantially constant level despite the concentration variations at the inlet, and a means (M3) for adjusting the level of the sludge blanket (V) and capable of maintaining said level at the lowest possible level.

Abstract: The invention relates to a method for controlling oxygen supply in a tank (2) for biologically treating wastewater by alternating aeration including consecutive cycles, wherein each cycle comprises a first aeration phase and a second anoxic phase for reducing nitrites and nitrates formed during the preceding aeration phase, the tank is provided with sensors for measuring ammonia nitrogen (4b) and for measuring nitrate (4c) and optionally for measuring oxygen (4a) that is dissolved in the tank liquor or in the liquor thereof exiting the tank, a method according to which the oxygen supply is controlled in the aeration phase when the reduction speed of the nitrate measurement is less than a bottom threshold and the cutoff of the oxygen supply is also controlled in the aeration phase when at least one of the following triggering events occurs: the reduction speed in the measurement of ammonia nitrogen becomes lower than a bottom threshold; the total sum of ammonia nitrogen and nitrate measurements becomes higher

Abstract: The invention relates to a method for drying slurry-like materials, in particular sludge from wastewater treatment plants, including two drying stages, namely: a first indirect drying stage (2), supplied with hot fluid, which receives sludge having an entry dryness Se, and outputs sludge having an intermediate dryness Si and water steam, which is channelled towards a condenser (8) in which a heating fluid, in particular water, is reheated and, in turn, heats a heating gas for a second drying stage (6); and a step (5) of forming strings of sludge at the exit from the first stage; the second stage (6) of drying the strings of sludge using gas at least partially heated by the heat extracted from the condenser, said second stage outputting a slurry having a final dryness Sf; the intermediate dryness Si is controlled according to the measured entry dryness Se and the desired exit dryness Sf, for minimum consumption of the total energy used for drying, the flow rate, pressure and/or temperature of the hot fluid (3)

Abstract: The invention relates to a device for filtering a liquid, in particular water, comprising membrane filtering modules, connected by pipes to valves for controlling the flows of liquid travelling towards the modules and coming from same, including a first block made up of an assembly (14a) of membrane filtering modules, a second block made up of a system of valves (14b), and a third block made up of a group of intermediate pipes (14c) comprising an interface between the system of valves (14b) and the assembly of modules (14), only the interface (14c) requiring to be changed when changing the type of filtering modules, while the system of valves (14b) and the assembly of modules (14a) remain unchanged, except when changing the type of modules.

Abstract: The invention relates to a method for desulphuration of the digestate and biogas in a digester (1) of urban and/or agricultural and/or industrial effluent, by biochemical and/or thermochemical processes, the digester consisting of an enclosure (2) which is closed at the top, in which anaerobic digestion of a mass of products to be treated making up the digestate (4) takes place, the digester comprising at least one loop (10) for external recirculation of the digestate; an oxidant is injected at least at one point (13, 14) of the loop (10), the injection conditions being as follows: the speed of circulation of the digestate in the loop (10) must be high enough to prevent the deposition of sulphur on the walls of the pipes; the contact time between the injected oxidant and the recirculated digestate recirculated from the injection point (13, 14) of the oxidant until the reinjection point (11 b) of the digestate must be long enough for all the oxidant to be dissolved in the liquid phase of the digestate; the amo