LIQUID EFFLUENT TREATMENT MODULE

Abstract

Liquid effluent treatment module comprising at least one tank portion suitable for receiving a plurality of packing elements that may receive a biological material, the tank portion defining a horizontal longitudinal axis and comprising at least one effluent feed, characterized in that the tank portion further comprises: .sup.∘at least one line for collecting treated effluent arranged in a central part of the tank portion and parallel to the horizontal longitudinal axis, .sup.∘at least one air injection line arranged in a lower part of the tank portion, off-centered and parallel to the line for collecting treated effluent so as to give rise to a spiral movement of the liquid effluents.

Claims

1. A liquid effluent treatment module comprising at least one tank portion adapted to accommodate a plurality of packing elements in suspension capable of accommodating a biological material, the tank portion defining a horizontal longitudinal axis and comprising at least one effluent supply, the tank portion further comprising: at least one treated effluent collection ramp arranged in a central part of the tank portion and parallel to the horizontal longitudinal axis, at least one air injection ramp arranged in a lower part of the tank portion, eccentrically and parallel to the treated effluent collection ramp, so as to cause a spiral movement of the liquid effluents, characterized in that the at least one effluent supply comprises at least one effluent supply ramp parallel and eccentric relative to the treated effluent collection ramp.

2. The treatment module according to claim 1, characterized in that the effluent supply ramp is arranged in an upper part of the tank portion.

3. The treatment module according to claim 2, characterized in that the effluent supply ramp is arranged in an eccentric manner relative to the air injection ramp.

4. The treatment module according to claim 1, characterized in that the air injection ramp, the effluent collection ramp and the effluent supply ramp are located from bottom to top on a diagonal plane of the tank portion.

5. The treatment according to claim 1, characterized in that the treated effluent collection ramp is arranged halfway between the air injection ramp and the effluent supply ramp.

6. The treatment module according to claim 1, characterized in that the tank portion comprises a lower part of curved or beveled section.

7. The treatment module according claim 6, wherein the lower part comprises a generatrix parallel to the horizontal longitudinal axis of the tank portion.

8. The treatment module according to claim 1, characterized in that the tank portion comprises a bottom and in that the air injection ramp is arranged on this bottom.

9. The treatment module according to claim 1, characterized in that the tank portion comprises a plurality of packing elements as well as liquid effluents, characterized in that the air injection ramp and the treated effluent collection ramp are arranged to allow by themselves the spiral movement of the liquid effluents.

10. The treatment module according to claim 1, wherein a tank is formed by two tank portions separated by a vertical plane of symmetry and comprises the at least one air injection ramp disposed in the vertical plane of symmetry.

11. The treatment module according to claim 1, characterized in that the tank portion comprises a sealed top cover as well as a gas collection device.

12. The treatment module according to claim 1, characterized in that the tank portion has a height of less than 3.05 m, for example from 2 m to 3 m.

13. A liquid effluent treatment system comprising at least one treatment module according to claim 1 as well as motorized effluent supply and air injection devices.

14. A liquid effluent treatment method using a treatment module according to claim 1, said method comprising the steps consisting of: providing a plurality of packing elements accommodating a biological material in a tank portion, supplying the tank portion with liquid effluents to be treated by the effluent supply, injecting air through the air injection ramp so as to create a movement of the liquid effluents in the form of a spiral, collecting the treated effluents by the treated effluent collection ramp, arranged in the central part of the tank portion.

Description

[0045] Other characteristics and advantages of the present invention will appear more clearly upon reading the following detailed description of one embodiment of the invention given by way of non-limiting example and illustrated by the appended drawings, in which:

[0046] FIG. 1 represents a three-quarter sectional view of an effluent treatment module according to the present invention,

[0047] FIG. 2 represents a top view of the effluent treatment module according to FIG. 1,

[0048] FIG. 3 represents a front sectional view of the effluent treatment module according to FIGS. 1 and 2,

[0049] FIG. 4 represents another effluent treatment module according to the present invention.

[0050] The present invention concerns a liquid effluent treatment module for accommodating packing elements containing or supporting a biological material allowing treatment or depollution of the liquid effluents. Preferably, this liquid effluent treatment module is transportable by sea and/or road, i.e. its dimensions and particularly its height are sufficiently small for it to be placed in an assembled form in a standard container.

[0051] In addition, the liquid effluent treatment module according to the present invention can be connected with other liquid effluent service and/or treatment modules so as to constitute a liquid effluent treatment station. For example, these modules can be pumping, control and analysis modules or effluent storage modules or physical, chemical or biological treatment modules, as known to those skilled in the art.

[0052] FIGS. 1 to 3 represent a liquid effluent treatment module 100 according to a first embodiment. This treatment module 100 comprises a tank 110 intended to accommodate liquid effluents to be treated, for example domestic and industrial wastewater that cannot be released as they are into the environment. In addition, the tank 110 can be adapted to accommodate mobile packing elements in suspension, preferably so as to allow their free circulation and rotation in the tank without the presence of walls, internal elements or reliefs leading to prevent or limit the movement of these packing elements or of the liquid effluents. For example, the packing elements are made of plastic material, composite or organic material and can accommodate a biological material and in particular microorganisms making it possible to treat or clean up the liquid effluents contained in the tank 110.

[0053] The tank 110 is provided with a vertical central plane of symmetry (not represented) defining two half-tanks or tank portions 110a and 110b and on which an air supply pipe 120a lies, as detailed below. The tank 110 has a U-shaped section, comprising an upper part 111 delimited by substantially parallel and vertical walls and a lower part 112 of curved section, i.e. comprising one or possibly several radii of curvature. The lower part 112 defines a bottom 112a which is for example an area of the lower part 112 where the tank 110 has a greater height. For example, the curved wall of the lower part 112 may consist of flat and elongate elements disposed next to each other so as to define together a radius of curvature, as represented in FIG. 1.

[0054] The tank 110 comprises a horizontal longitudinal axis as well as two ends on either side of the U-shaped section, each closed by a vertical plate 113. Thus, each tank portion 110a and 110b comprises one half of the lower part 112, one half of the upper part 111 and two halves of vertical plates 113. Preferably, the walls of the tank are formed of a solid and sealed material, such as stainless steel, aluminum, a plastic material or a composite.

[0055] In addition, the tank 110 accommodates in its lower part 112 an air injection ramp 120 located for example on the vertical plane of symmetry and between the tank portions 110a and 110b. Thus, the air injection ramp 120 can be put or placed in the vicinity of the bottom 112a and can be surmounted by the largest column of liquid existing in the tank 110. This air injection ramp 120 is connected by the air supply pipe 120a to an air injection system comprising for example a compressor (not represented) and providing an air pressure greater than the pressure of the liquid column applying on the air injection ramp 120, so as to achieve an injection of air into the lower part 112 in the form of air bubbles, as known to those skilled in the art.

[0056] In addition, in FIGS. 1 to 3, the tank 110 comprises two treated effluent collection ramps 130 parallel to the longitudinal axis of the tank and preferably protruding from one of the vertical walls or plates 113 and located in a central part of each of the tank portions of 110a and 110b, for example at mid-height of the tank 110 and/or between the upper part 111 and the lower part 112. Thus, the treated effluent collection ramps are located in a horizontal plane between the top of the tank 110 and the bottom 112a or between the level of the effluents 150 contained in the tank 110 and the air injection ramp 120.

[0057] In addition, the treated effluent collection ramps 130 can each be located halfway between a vertical wall of the tank 110 and the vertical plane of symmetry. In other words, each treated effluent collection ramp 130 can occupy a central part of the volume of each tank portion 110a, 110b, for example on the horizontal longitudinal axis passing through the isobarycenter of each tank portion.

[0058] These treated effluent collection ramps 130 are intended to collect and discharge the treated liquid effluents and are hydraulically connected to another liquid effluent treatment element or to a treated liquid effluent discharge and/or storage device (not represented).

[0059] Finally, each tank portion 110a and 110b comprises an effluent supply ramp 140 extending from one of the vertical plates 113, in the upper part 111 of the tank 110, for example in a horizontal plane at the top of the tank 110, preferably above the level of effluents 150 in the tank 110. The effluent supply ramp is also eccentric relative to the air injection ramp 120 and is located in the vicinity of a wall of the tank 110, parallel to the longitudinal axis of the tank 110.

[0060] Thus, the air injection ramp 120, the treated effluent collection ramp 130 and the effluent supply ramp 140 can be located from bottom to top on a diagonal plane of each tank portion 110a, 110b. In addition, the treated effluent collection ramp 130 can be located halfway between the air injection ramp 120 and the effluent supply ramp 140 (see FIG. 3).

[0061] The effluent supply ramps 140 are connected, for example, to an effluent supply pump and/or to an effluent storage tank (not represented). These effluent supply ramps 140 are intended to supply, for example continuously, the tank 110 with liquid effluents to be treated, so as to maintain an approximately constant level of effluents 150 in the tank 110. Thus, the supply flow rate can be substantially equal to the effluent discharge flow rate.

[0062] The ramps used for the supply and discharge of the effluents are perforated and/or latticed cylindrical elements extending over a major part of the length of the tank 110, for example over a length greater than or equal to half or three-quarters of the length of the tank or over the entire length of the tank. For example, the supply ramps 140 of FIGS. 1-3 are perforated with ports oriented only downwards or at least located in the lower part of the supply ramps, which allows contributing to the spiral movement of the treated effluents.

[0063] In addition, the air injection ramp 120 can be fitted with perforated transverse tubes, in order to ensure a flow rate and an optimal distribution of the injected air. Alternatively, other elements known to those skilled in the art can be used, such as longitudinal latticed elements, in particular for the treated effluent collection ramps 130.

[0064] FIG. 3 represents a liquid effluent treatment tank 110 in operation. It is thus provided with the air injection ramp 120 put on the bottom 112a at its center or on a vertical plane of symmetry, of the vertical air supply pipe 120a located on the vertical plane of symmetry. It further comprises the two treated effluent collection ramps 130 in a median horizontal plane and the two effluent supply ramps 140 in the upper part 111 of the tank 110, for example at its top. Thus, in the embodiment of FIGS. 1-3, only one air injection ramp 120 is used for each of the tank portions 110a and 110b. Alternatively, one or more air injection ramps can be provided in each of the tank portions.

[0065] In addition, in each tank portion 110a, 110b, a treated effluent collection ramp 130 is located in a central part of the tank portion while the air injection ramp 120 is off-centered or eccentric relative to this central part and located in the lower part 112. For example, the air injection ramp 120 is offset both on a transverse axis and on a vertical axis, relative to each of the treated effluent collection ramps 130, but is parallel and/or aligned on the same horizontal longitudinal axis.

[0066] In operation, in each tank portion 110a and 110b, the air injection ramp 120 creates an ascending air bubble stream FA from the bottom 112a of the tank 110, which causes an ascending stream of the effluents in each of the tank portions 110a, 110b. Due to the treated effluent collection ramp 130 located in the central part of the tank portion 110a, 110b, a spiral movement MS of the liquid effluents is created, which allows an optimal movement of the packing elements and therefore an optimized treatment of the liquid effluents in a restricted width and particularly in a limited tank height. In addition, no mechanical stirring is necessary, which limits the cost of the treatment module according to the present invention as well as the energy consumption during its operation. In the embodiment of FIGS. 1 to 3, two spiral movements of the liquid effluents occur during operation, one in each tank portion 110a, 110b.

[0067] In addition, the effluent supply ramps 140 create in each tank portion 110a, 110b a descending stream CD of liquid effluents to be treated along the walls of the tank 110 which allows strengthening this spiral movement MS of the effluents and therefore the mixing of the packing elements. The efficiency of the treatment of the effluents in the treatment module according to the present invention is therefore enhanced and the air injection flow rate can be limited, thus limiting energy consumption.

[0068] Thus, the tank 110 of the present treatment module 100 can be seen as comprising two tank portions 110a, 110b each adapted to allow a spiral movement of the packing elements and of the liquid effluents and comprising, to this end, two treated effluent collection ramps 130 each arranged in a central part of the spiral movement of the liquid effluents as well as the air injection ramp 120 arranged in an external or eccentric part of the spiral movement (s), for example in the lower part 112 of the tank portion 110a, 110b, i.e. below the treated effluent collection ramp 130.

[0069] The specific positioning of the treated effluent collection ramp 130 of each tank portion 110a, 110b relative to the air injection ramp 120 thus allows creating a spiral movement of the effluents contained in the tank in order to obtain an optimal treatment of the effluents in a tank of reduced width and especially of minimum height. A liquid effluent treatment module comprising such a tank can therefore be easily transported in an assembled form to be easily installed permanently or temporarily far from its place of manufacture.

[0070] The effluent supply ramp 140 of each tank portion 110a, 110b is preferably located in an eccentric or external part relative to the spiral movement of the effluents, for example in the upper part 111 of the tank 110, which can contribute to the creation and maintenance of the spiral movement of the effluents in a tank of minimum height without a large air flow rate and therefore with a limited energy consumption.

[0071] In the embodiment of FIGS. 1 to 3, the air injection ramp 120 is unique and comprises a longitudinal central segment as well as shorter transverse segments. However, the air injection ramp can take an alternative shape as explained below.

[0072] Thus, in the embodiment of FIG. 4, a liquid effluent treatment module 200 is identical to the liquid effluent treatment module 100 according to FIGS. 1 to 3, except for the air injection ramp 220. This indeed comprises three longitudinal segments 220a, 220b, 220c each provided with perforated air injection discs 221. These perforated air injection discs 221 allow a distribution of the air bubbles in a large volume and may therefore be preferable for some tank volumes, some types of tanks or some types of liquid effluents to be treated.

[0073] It will be understood that various modifications and/or improvements obvious to those skilled in the art can be made to the different embodiments of the invention described in the present description without departing from the scope of the invention defined by the appended claims. Particularly, reference is made to the air injection ramp 120 which can take any suitable shape, other than the shapes represented in the present figures. In addition, the air injection ramp 120 may extend over part or the entire length of the tank 110 and at a distance from or in the vicinity of a wall of the tank or the tank portion.

[0074] Likewise, the treated effluent collection ramps 130 can extend over part or the entire length of the tank 110 and can have a terminal portion open in their end oriented in the tank or the tank portion, as in the present figures, or preferably closed. For example, the terminal portion is closed by a T-tube for collecting the treated effluents from one or more other adjacent similar modules.

[0075] In the case where several liquid effluent treatment modules according to the present invention are connected in series, the terminal portion can be closed by a T-tube, a first horizontal branch of the T can therefore be connected to the collection ramp collecting the effluents from the treatment module. A second horizontal branch of the T can be connected through the vertical wall of the tank portion to the collection ramp collecting the effluents from another adjacent treatment module. Finally, the vertical branch of the T can be open and oriented for example upwards or downwards of the tank portion of the treatment module. Thus, thanks to a T-shaped sleeve, the treated effluents collected from another adjacent treatment module can be reinjected at least partially into the tank portion of the treatment module, which allows improving the treatment of the effluents and therefore the quality of the effluents collected after treatment.

[0076] The effluent supply ramps 140 preferably have an open end and can also extend over part or the entire length of the tank 110. In addition, they can be arranged in the vicinity of or at a distance from a wall of the tank 110 or the tank portion. They can also be arranged below the level of the liquid effluents, in particular if they are coupled to pumping means that allow overcoming the pressure of the liquid effluents. They preferably include ports oriented downwards, i.e. towards the lower part of the tank portion.

[0077] Finally, the tank 110 is not limited to a U-shaped section, but may have another shape or another section, for example a lower part of beveled shape or a flat bottom and/or a rounded or curved upper part. The tank 110 may be provided with a top cover, not represented, which can be sealed, so as to improve the efficiency of the biological effluent treatment reaction. This cover may be optionally provided with a gas collection device, so as to limit the odors generated by the treatment module during its operation and/or to upgrade the gases formed.