Abstract: A single tank submerged membrane bioreactor for treating feed water having unacceptable levels of ammonia or total nitrogen has both a membrane scouring bubble supply and an oxygenating bubble supply. The membrane scouring bubble supply continuously provides large scouring bubbles to clean the membranes. Permeate is continuously withdrawn from the membranes at a high rate but the large scouring bubbles do not transfer sufficient oxygen to the mixed liquor to create aerobic conditions in the reactor. The oxygenating bubble supply is operated to provide small bubbles of air or oxygen that intermittently produce aerobic conditions in a significant part of the mixed liquor. Alternating aerobic and anoxic conditions occur in a significant portion of the tank suitable for nitrification and denitrification.

Abstract: A process is described for testing the integrity of liquid filtration membranes without the use of pressurized air. The process includes draining the upstream compartment 3 and filling it with air by venting it to the atmosphere; applying a partial vacuum to the permeate compartment 4 to create a pressure difference across the membrane 2; and measuring the liquid flow out of the permeate chamber that corresponds to air passing through the leak orifices in the membrane. After stabilization of the pressure in the permeate chamber, the resulting constant liquid flow rate out of the permeate chamber is then used to evaluate the integrity of the membrane. An installation for implementing the process is also described and can include a plurality of filtration modules.

Abstract: The invention relates to a method for checking and regulating the pressure loss in a biological filter of the type comprising an immersed filter bed (2) consisting of at least one layer of granular filtration material, the said granular material layer acting as a support for a biomass used to degrade carbon-based and/or nitrogen-based pollution in water to be filtered, characterized in that it comprises a step consisting of continuously or discontinuously injecting at least one coagulating agent (1) into the said water before its entry into the said filter.

Abstract: In a method of treating an untreated flow of liquid charged with particles and/or colloids, the flow is caused to flow in a coagulation zone that is kept turbulent and in which the flow is mixed with a coagulant. The untreated flow and a granular material which is insoluble in and more dense than the flow are caused to flow in an intermediate zone in which the granular material is maintained in suspension. The flow with substantially all of the added granular material and the colloids or particles aggregated therein is caused to flow in a sedimentation zone in which a clarified effluent is separated from sludge consisting of the granular material and the aggregated particles or colloids. The sedimentation zone has an undivided flow cross section, with no separator plates and the effluent is caused to flow therein at an average settling speed of at least 15 m/h.

Abstract: The invention relates to a method for regulation of aeration in a biological filter of the type comprising conveyance means (3) bringing water to be filtered into the lower part of the filter, a filter bed (2) acting as a support to the biomass, means of distributing an oxygenated gas (5, 5a) in the filter bed (2), a layer of filtered water (7) above the said filter bed, a nozzle for (4) of discharging the filtered water in the upper part of the filter, characterized in that it consists of taking account of the efficiency Ct with which the biomass uses the distributed oxygen to regulate the said distributed oxygenated gas flow and/or its concentration in molecular oxygen, in order to optimize the quantity of molecular oxygen distributed by the said distribution means.

Abstract: The invention relates to a process of aqueous phase oxidation of effluents, consisting of subjecting said effluents to oxidation in the presence of at least one catalyst and of at least one oxidising agent, at a temperature of between approximately 20.degree. C. and approximately 350.degree. C., under a total pressure of between approximately 1 and approximately 160 bars, in such manner as to mineralise part of the organic matter and total ammoniated nitrogen contained in said effluents, said oxidation being carried out inside a reactor in which a gaseous phase is set up above the liquid phase consisting of said effluents.characterized in that said catalyst is a heterogeneous catalyst placed inside said reactor above the interface between said gaseous phase and said liquid phase.

Abstract: This invention relates to a plant for the biological treatment of water to produce drinking water, characterized in that it comprises at least one biological reactor (7) provided with injection means (9) for injecting oxygenated gas, at least one separation membrane (11 for microfiltration or ultrafiltration immersed in said reactor (7), and addition means (10) for adding to said reactor (7) at least one pulverulent material in suspension serving as a support for a biomass, said pulverulent material possibly being a reactive powder which also allows fixation of the substrate required by said biomass.

Abstract: The invention relates to a process for the stabilization of sludge or other waste with a high organic matter content derived from treatment operations of industrial and/or urban effluent, or from drinking water treatment operations of surface or ground water, said sludge containing at least one part dry matter essentially made up of fermentable organic matter, characterized in that it is conducted at ambient temperature and atmospheric pressure, and in that it comprises a stage consisting of acidifying said sludge with at least one strong acid to a pH of between 1.5 and 3.5, a stage consisting of adding at least one nitrite salt to said sludge at a concentration of between 10 and 500 mg N.NO.sub.2 /l sludge, and in that it consists of maintaining the mixture made up of said sludge, said acid and said nitrite salt in contact for a period of between 5 minutes and 12 hours, under permanent or intermittent mixing.

Abstract: A method for the purification and biodeodorizing of a gas effluent charged with pollutant matter is provided. The method includes the steps of passing the gas effluent through a bed of inert granular material used as a support for a biomass. The biomass includes bacteria, majority of which are autotrophic bacteria. Preferably the bacteria are in a form designed to degrade the pollutant material. The method includes the step of sprinkling the bed with a sprinkling liquid and recovering purified biodeodorized gas effluent. Preferably, nutrient elements for the biomass are supplied entirely by the sprinkling liquid, the gas effluent or a mixture thereof.

Abstract: In a method of treating an untreated flow of liquid charged with particles and/or colloids, the flow is caused to flow in a coagulation zone that is kept turbulent and in which the flow is mixed with a coagulant. The untreated flow and a granular material which is insoluble in and more dense than the flow are caused to flow in an intermediate zone in which the granular material is maintained in suspension. The flow with substantially all of the added granular material and the colloids or particles aggregated therein is caused to flow in a sedimentation zone in which a clarified effluent is separated from sludge consisting of the granular material and the aggregated particles or colloids. The sedimentation zone has an undivided flow cross section, with no separator plates and the effluent is caused to flow therein at an average settling speed of at least 15 m/h.

Abstract: A process for the treatment of aqueous effluent with a view to its purification, the process including at least one stage consisting of causing the water to pass into the interior of at least one battery of several biological filters with fixed cultures or other devices with fixed cultures operating in parallel, characterized in that it comprises supplying the filters at constant flow and to cause the number of filters supplied and the number of filters not supplied in the battery, to be varied, in accordance with the total flow of aqueous effluent to be treated. Such a process allows the performance of biofilters and other devices with fixed cultures to be improved.

Abstract: An untreated flow of waste water is normally introduced into a plain sedimentation unit during plain sedimentation periods to separate it into sand and a flow treated by plain sedimentation. During other periods, for example periods of heavy rain, a coagulating agent, ballast sand and a flocculating agent are introduced. The coagulated flow is passed into a maturation intermediate area and then, with substantially all the sand and colloids of particles attached to it, into the plain sedimentation unit. Here effluent is separated by plain sedimentation and evacuated and sludge made up of the sand and the adhering colloids and particles is extracted and evacuated via an extraction system and the sand outlet channel of the plain sedimentation unit. The sludge is collected, the ballast sand is separated from it to be recycled into the sand injection area and the sludge and excess sand are extracted.

Abstract: The invention relates to a reactor for UV radiation for the disinfection of liquids comprising at least one high or medium pressure UV emitter (1) arranged coaxially inside a protective sheath (2) transparent to UV, the assembly formed by the emitter and the sheath being located coaxially inside a tubular shell (3) whose internal face reflects at least 30% of the incident UV at 250 to 260 nm coming from the emitter (1), the liquid to be treated transiting according to a flow pipe in an active chamber (4) defined by the internal face of the shell (3) and the external face of the sheath (2), the reactor being characterized in that it is connected to washing means (30) of the active chamber (4) including means making it possible to make a cleaning liquid circulate in the active chamber (4) and air injection means (8) provided upstream from the active chamber (5) making it possible to improve the turbulence of the cleaning liquid during washing.

Abstract: To purify untreated water, for example waste water, containing organic pollution, materials in suspension and nitrogen-containing pollution, reagents are added under conditions adapted to coagulate all of the materials in suspension, including colloidal materials, to form granular physical/chemical floc. Diluting water is added, preferably after the reagents, in a flowrate ratio of at least 2/1. The dilute flocculated water is caused to flow through a bed of sludge in the form of such dense and granular floc and denitrifying bacteria. The bed is subject to turbulent but intermittent agitation. A denitrified effluent is recovered. This denitrified effluent is caused to flow through a biological filter or preferably through a fluidized bed containing nitrifying bacteria and into which oxygen or air is injected. A clarified effluent is obtained, some of which is recycled as the diluting water.

Abstract: System for injecting slurry to be incinerated into an incineration furnace, the furnace having an incineration hearth onto which the household waste is tipped in order to be incinerated, and including a device for injecting the slurry to be incinerated into the furnace, essentially fitted above the incineration hearth in such a way as to allow the slurry to be fed to the hearth at least in part by gravity, the injection device being fitted with a spray device to spray the slurry when it is injected into the furnace, wherein the said injection device has an injection casing forming a spray chamber with a slurry feed intake, and a discharge nozzle, for injecting the slurry into the furnace, the said chamber being crossed by a pressurized air injection tube, the end of which is fitted with a diffuser in the area of the nozzle of the said chamber, the said injection casing being mounted onto a pivot and working together with a telescopic rod for adjusting the angle of the injection casing by rotation around the s

Abstract: A process and device for combined oxidation of polluted water, e.g. industrial waste water or effluents, to make it suitable for drinking, involves injection of hydrogen peroxide (pure aqueous solution or diluted) and ozone (gaseous, or ozonized oxygen or air) simultaneously and in a flow direction co-current with the circulation of the water to be treated, at the inlet of the oxidation reactor. For example, a reactor is endowed with mechanisms to inject ozone and hydrogen peroxide at its base, at very closely-spaced points and simultaneously, in a flow direction the same as the water to be treated, with an automatic control system to regulate the levels of the oxidizing agents.

Abstract: The water to be treated is sent in a co-current with oxygenated gas into an upflow reactor with a fixed bed of particles, and the bacteria support medium used comprises particles with a bulk density of 35 to 65 kg/m.sup.3. The reactor or biological filter (or reactors or biological filters in series) comprises or comprise: a zone for the densification of sludges; at least one oxygenated gas injection device; a zone of filtering material, a retention ceiling and a washing water storage zone with removal of the treated effluent. Application to the treatment of wastewater and water to be made fit for drinking purposes.

Abstract: A process for the biological treatment by nitrification and/or denitrification of an effluent containing nitrogen pollution includes the following steps:an incident flow of this water is brought into a mixing zone with at least one compartment in which, by turbulent mechanical agitation, an inconsumable and insoluble granular material, loaded with biomass, is put in homogeneous suspension in this water, and is maintained at a more or less constant mass concentration;this water and this granular material in suspension are circulated in a separation zone from which is extracted on the one hand clarified water, and on the other hand biomass loaded granular material; andalmost all of the active biomass fixed on said granular material is brought back by forced recycling to the mixing zone.

Abstract: A process and apparatus for biological purification of waste water wherein waste water and oxygenated gas are introduced into a reactor using ascending cocurrents. The reactor is equipped with a lower fluidized bed and an upper fixed bed for filtration. The particles in the beds are composed of expanded materials having a density less than 1. The particles in the fixed bed are both smaller and lighter than those of the fluidized bed.

Abstract: A process is provided for producing extruded or molded objects from waste containing plastic materials. The process includes the following steps: preliminary physical treatment, optional drying, preheating to a temperature of from 80.degree. to 160.degree. C., mixing at a temperature of from 120.degree.-250.degree. C., and injection molding or extrustion.