Abstract: A method of biologically purifying liquids that are heavily contaminated with organic or inorganic impurities, by using bacteria in the presence of a solid support on which bacteria can be fixed, comprises the following steps: the liquid to be purified is continuously injected without prior filtering into a reactor in which a solid support having grain size lying in the range 1 mm to 5 mm and density lying in the range 1.01 g/cm.sup.3 to 1.3 g/cm.sup.3 has been put into turbulent motion by blowing in gas in the presence of bacteria and while satisfying the conditions required by the metabolism of the bacteria; and the treated liquid is taken continuously from the reactor after a transit time that is long enough to ensure purification of the impurities contained in the liquid to be purified.

Abstract: Process for purifying and filtering fluids, especially water, containing suspended contaminants and using gravity separation means as well as membrane separation means, in a finishing stage, comprising the step of introducing a pulverulent reagent into the fluid stream to be treated downstream of the gravity separation and upstream of the membrane separation, wherein said pulverulent reagent is recycled from the purge of the membrane separation means to the upstream of the gravity separation means.

Abstract: A process for the production of a porous organic material, in particular an organic semi-permeable membrane, provided with a plurality of separate passageways, comprising dissolving a polymer in a solvent, using a drawplate comprising needles having a shape conjugate with that of the passageways and external dimensions comprising between 0.7 and 1.2 times those of said passageways and an extrusion orifice of a conjugate fome to that of the extrudate and of internal dimensions comprising between 0.8 and 1.2 times those of said extrudate, injecting around the needles a solution having a viscosity greater than 500 millipascal-second, introducing into the interior of the conduits of the drawplate a centering fluid which is a non-solvent with respect to the polymer and able to precipitate the polymeric solution, causing the extrudate to travel from the output of the drawplate a distance da in a gaseous atmosphere which is non-precipitating with respect to the polymeric solution such that 500.times.e<da<0.

Abstract: A method of treating water with activated sludge, comprising a process for depolluting said water including a stage in which carbon pollution is oxidized, a nitrification stage which may optionally be associated with a denitrification state and/or a dephosphating stage, and a sludge ageing process. The method further includes a sludge concentration stage, said stage being performed upstream from the sludge ageing stage, said concentration being performed by phase separation using compressed air, e.g. in a flotation tank (3), and the concentrated sludge being recycled via the sludge ageing stage.

Abstract: A process for the production of a porous organic material, in particular a semi-permeable membrane, comprising a plurality of separate passageways, including dissolving a polymer in a solvent, using a drawplate having needles of a shape conjugate with those of the passageways and of external dimensions between 0.7 and 1.2 times those of the passageways and an extrusion orifice of a shape conjugate those of the extrudate and of internal dimensions comprising between 0.8 and 1.2 times those of the extrudate, injecting around the needles a solution having a viscosity greater than 500 mPa.s and introducing a centering fluid into the interior of these needles, recovering the extrudate at the output of the drawplate in a precipitating medium in such a manner that the extrudate travels in the medium a distance such that 800.times.

Abstract: A housing made of plastic material for hollow fiber filter modules, includes both an abutment ring close to that end thereof which will be the bottom end after the module has been mounted vertically, and a centering ring at a short distance from the opposite end.

Abstract: A method of changing operating modes in automatic water filtering apparatus comprising inside-skin tubular membrane modules for filtering water, the possible filtering modes being: dead-end filtering; cross-flow filtering; and cross-flow filtering with continuous purging; both cross-flow filtering modes including recirculation in a loop; wherein two types of triggering are provided for filter membrane backwashes, a first one of said types being related to time periods between two backwashes, which time periods are predetermined for each mode of filtering, and a second one of said types being related to reference values of an operating parameter of the automatic apparatus, which values are predetermined for each mode of filtering; with the mode of filtering being changed after a backwash has been triggered in response to one of the reference values, with changes taking place in the following order: dead-end filtering, cross-flow filtering, cross-flow filtering with continuous purging, or vice versa.

Abstract: The invention relates to an extrusion plate for the production of membranes of an organic material including at least one longitudinal passageway. This extrusion plate includes an annular body (1) provided with a cylindrical cavity into which opens at least one radial fluid conduit (5), an upper ferule (3) adapted to be inserted into the cavity of the body and comprising at least one hollow needle (8) extending in the extension of said insert and a longitudinal centering fluid feed conduit (9), and a lower insert (4) adapted to be inserted into the cavity of the body and having a bore (6) defining an extrusion chamber around the needles (8). The upper (3) and lower (4) inserts are in abutment at assembly faces at the level of which open the fluid conduits (5), and a fluid passage (7) is provided on these opposing faces in continuity with the passages (5), for communicating with the extrusion chamber.

Abstract: A method for regulating the residual free chlorine in drinking water, characterized in that the regulation is carried out by introduction of a quantity of chlorine determined as a function of the chlorine demand at "the head" of the line, that is upstream of the water treatment or storage line, while obtaining in the distribution network, water having an acceptable residual free chlorine content. The chlorine demand of the water at the inlet of the treatment, or storage line is rapidly determined by accelerating, the reactions tied to disinfection by heating so as to obtain over a short period (from 5 to 10 minutes) water having a residual free chlorine content corresponding to the required value.

Abstract: A method of manufacturing a unit assembly of filter membranes obtained by precipitating a polymer solution, comprises the following steps: a plurality of elongate porous elements are placed in an outer shell having a closed end and an open end, the elongate elements passing through said closed end and having longitudinal axes which are parallel to one another and to the direction extending between the two ends; injecting the polymer solution around the porous elements; injecting a fluid into one end of the elements, the fluid diffusing through the elements towards the polymer; and removing the polymer solvent which diffuses in the opposite direction from the other ends of the elements, thereby causing the polymer to precipitate and form a porous polymer structure around the porous elements and between them, with the porous structure having in contact with the porous elements a skin of adjustable porosity then removing the porous elements in order to unmold a porous polymer block pierced by channels whose long

Abstract: Contact surfaces of a water meter (1) and a base (2) of a meter support (3) comprising a water inlet duct (4) and a water outlet duct (5) are each bordered by an annular shoulder (6, 7). An assembly ring (8) is provided so as to keep the two annular shoulders (6, 7) in contact, this ring (8) comprising slits (9) separating a series of elastic fingers (10). The ring (8) comprises moreover on its inner face an annular groove (11) complementing the two annular shoulders (6, 7). A rigid collar (15) force-fitted onto the elastic fingers (10) and bearing against outwardly projecting lugs (12) at the ends thereof keeps the annular groove (11) against the annular shoulders (6, 7) which are in contact.

Abstract: An apparatus for the dissolution of ozone in a fluid such as water, for its treatment by the ozone, by injection in said fluid of ozonic air or ozonic gas, including at least one tube placed vertically in a vertical tubular enclosure and communicating with this enclosure via its lower end and via its upper end with means for supplying the fluid to be treated and the ozonic air or ozonic gas. Said vertical tubular enclosure is closed at both its ends and provided with means for the discharge of the fluid treated and of the ozonic air or gas in excess, characterized in that it is provided with means for the injection of hydrogen peroxide so as to complete the oxidation reaction through a radical route.

Abstract: A filter module comprises a bundle of filter fibers mounted in a housing. The bundle is provided with a heat-shrink sheath placed over a sleeve containing the bundle, with the sheath being placed level with lateral inlet/outlet orifices through the housing so as to act as a baffle against incoming liquid.

Abstract: The invention relates to a process and an apparatus for the production of a bundle of filaments from at least one filament, and its application especially to the production of a bundle of hollow semi-permeable fibers used for producing a filtration module. According to this invention, the filaments (1) is wound in a first step, in several superposed layers around a support plate (10) having two take-up edges (17) perpendicular to the direction of winding of the filament, and conferring on this filament an alternating transverse movement of decreasing amplitude in such a manner as to achieve a winding having a predetermined profile. The support plate (10) is then removed by retracting the take-up edges (17) toward each other so as to obtain a bundle having a transverse section which is a function of the profile of the winding and curved ends.

Abstract: A method of fabricating a tube plate for a hollow fiber separator apparatus, from a set of hollow fibers with an end of the set being embedded in a resin, wherein the set of hollow fibers is subdivided into a plurality of elementary bundles, at least a first end of each elementary fiber is enclosed in a reinforcing element and the first ends are stuck together using a resin in order to form a reinforced tube plate. The invention also relates to tube plates and to hollow fiber separator devices.

Abstract: A method of detecting changes in a surface state and of monitoring said surface state, in particular for a body whose surface is at a given temperature and is in contact with a flowing liquid at a given temperature which may optionally be different from the temperature of said surface, wherein a reference metal body is placed in said liquid, said body having a surface at a temperature which is adjustable independently of the temperature of said liquid, and said body acting as an electrode which is optionally raised to an adjustable potential, and the surface state of said body is detected by measuring the intensity of light radiation reflected from at least one mirror-forming portion of the surface of the reference body.

Abstract: The device for connecting and supporting a water-meter (1) comprises a water-inlet pipe (2) and a water-outlet pipe (3) secured in a support (8). The support comprises a stationary seat (9) in which are mounted the water-inlet pipe (2) and the water-outlet pipe (3). The seat carries a plate (10) comprising two conduits (11, 12) designed to be connected to inlet (4) and outlet (5)-apertures on the meter (1). The plate (10) is mounted to rotate upon seat (9) about an axis (X-X') for the purpose of opening up or shutting off the flow of water, or for testing the meter.

Abstract: An apparatus for dissolving ozone in a fluid includes a vertically extending closed chamber, and at least one tube extending vertically into the chamber and having a lower end opening into the chamber. Fluid to be treated and ozonized gas is introduced into the upper end of the tube, such that the fluid and gas pass downwardly through the tube, are discharged from the lower end of the tube into a lower end of the chamber, and then passed upwardly through the chamber, whereby ozone dissolves in the fluid. Structures are provided at the upper end of the chamber for discharging fluid having dissolved therein the ozone and excess gas.

Abstract: A filtration apparatus includes at least one tangential filtration module ving at least one filtration element defining a conduit arranged in a spiral configuration within an enclosure in the form of a body of revolution. The element defines a helicoidal slope for liquid to be filtered and causes such liquid to pass through the module along a helicoidal path. The liquid is tangentially filtered, and filtrate is delivered to the exterior of the module.

Abstract: An apparatus for carrying out a liquid-liquid extraction process by co-current contact between an extraction liquid and a liquid from which impurities are to be extracted includes a mixing compartment in the form of a vertical column having an open lower end and equipped in its interior and substantially throughout its length with a rotary element having surfaces extending perpendicularly or obliquely to the axis of the element. The open lower end of the column extends into a settling compartment in the form of a leak-proof container provided with means for determining the level of the extraction liquid in the container. The extraction liquid is recycled from the container by being converted to a gas and then reintroduced into the column. Compressed air is controlled electronically to supply make-up extraction liquid and any necessary reagents into the settling container to ensure that the level of the extraction liquid is maintained constant.