FR3018209A1 - FIXING BRACKET FOR BACTERIA - Google Patents

Abstract

The present invention provides a bacterial attachment support of plastic / vegetable composite material comprising a support body with a plurality of spaced lamellae, at least two lamellae of the plurality of lamellae having substantially parallel ends, the support body having a means anti-entangling of the support with an identical or similar support, wherein the anti-entanglement means comprises a peripheral belt adapted to prevent entanglement of the support lamellae with lamellae of the same or similar support.

Description

The present invention relates to the field of non-collective sanitation, in particular the treatment of domestic wastewater or the like.  More particularly, the present invention relates to a bacterial attachment support.  [2] There are processes and tanks or water treatment plants using a bacterial culture, ensuring the biological reactions involved in the treatment of wastewater and in particular the oxidation and reduction of carbonaceous and nitrogenous materials.  [3] Several major steps are needed: decantation, anaerobic pretreatment, aerobic treatment, clarification.  Existing stations typically comprise different compartments, in which the different steps are performed, with the possibility of additional steps, such as a pre-clarification step prior to clarification and discharge of clean water.  [004] In a non-collective sanitation process for the purification of free-culture activated sludge type sewage with secondary settling, it is often provided: an initial step of anaerobic digestion in an anaerobic digestion compartment, a step subsequent aerobic purification in an aerobic treatment compartment, with an air distribution, and a subsequent decantation step in a settling compartment.  An example of a process is such that the substances having undergone the aerobic purification step pass through the sludge bed obtained in the settling stage, in the up-down direction, the decantation step thus also being a biological reaction step between the materials having undergone the aerobic purification step and preparing to undergo the decantation step and sludge sludge obtained in the decantation step.  However, this process generates water flows with suspended solids capable of disturbing the settling, which affects the performance of such a process.  F27287FRD1 [6] According to a well-known process in itself, a non-collective sanitation device is used for the purification of free-culture activated sludge wastewater with secondary settling, comprising, from upstream to downstream: an anaerobic digestion compartment, provided with a wastewater supply to be cleaned and purified located in the upper part, an aerobic purification compartment, provided with air distribution means, a settling compartment, provided with deflection means and an evacuation of purified and purified water, said evacuation being located in the upper part, a passage for materials between the anaerobic digestion compartment and the aerobic purification compartment, a passage for materials between the aerobic purification compartment and the settling compartment.  [7] Thus, the settling compartment is also a compartment for biological reaction between the materials coming from the aerobic purification compartment and preparing to pass into the settling compartment and the mud bed sludge that is lying in the compartment. decanting.  [8] For biological reactions of growth supports, fixed and immersed in one or more treatment tanks, have been developed, as a support for fixing bacteria.  The different bacteria then agglomerate in biofilm on the support.  [9] Current known carriers are plastic supports.  It is noted, however, that plastic supports, if they are too small, can be washed away in treated wastewater and create environmental nuisances, whereas too large plastic supports have a small surface area.  Similarly, the supports made of open-cell foam or with slats having a too narrow space, do not allow maximum development of the biofilm (insufficient size of the cells), and can clog over time.  An object of the present invention is to provide a bacterial carrier.  The present invention relates to a bacterial fixation support made of a plastic / plant composite material obtained according to the method described.  According to the invention, a bacterial fixing support, comprising a support body with a plurality of spaced lamellae, at least two lamellae of the plurality of lamellae having substantially parallel ends, the support body having a means of anti-entangling of the support with an identical or similar support, wherein the anti-entanglement means comprises a peripheral belt adapted to prevent entanglement of lamellae of the support with lamellae of the same or similar support.  Thus, the present invention proposes to provide a fastening support of a peripheral belt, which prevents the nesting of several supports and also constitutes a protection against shocks, in particular between several fixing brackets, thus protecting, in particular use in a wastewater treatment device, the biofilm accumulated on the support.  In addition, such a belt preserves the integrity of the support.  [0014] Advantageously, an inter-lamellar space is at least equal to or greater than 10 mm.  Such an inter-lamellar space allows, in use, a biofilm growth on all the free surfaces, while avoiding the different parts of the biofilm to touch and agglomerate with each other.  Thus, the inter-lamellar space is chosen to preserve the useful surface of the fixing support.  In one embodiment, the fixing support comprises a central plate, from which a plurality of first lamellae extend, and at least one plate connecting plate, interconnecting lamellae of the plurality of first lamellae, and second lamellae extending substantially from the connecting plate.  Advantageously, the arrangement of two plates from which lamellae extend makes it possible to increase the specific surface area of the fixing support.  Preferably, the support comprises a plurality of third lamellae, extending from the central plate and symmetrical on either side of the central plate by F27287FRD1 relative to the plurality of first lamellae, connecting together lamellae of the plurality of third lamellae, fourth lamellae extending substantially from the second connecting plate.  Advantageously, the support thus has a symmetry, to adjust the performance of the support, and in particular the positioning of the support in a volume of water.  In one embodiment, the support comprises one or more of the following characteristics: a skeleton structure in the form of one or more rings, a skeleton structure comprising at least one central plate from which the lamellae extend, symmetrically on both sides of the wafer, and elements connecting the free ends of the slats.  Advantageously, the support comprises a size between 5 and 7 cm, preventing, when the support is used in a wastewater treatment device, to escape, which would lead to a reduction in flow or a blockage of pipes, and could also lead to outdoor pollution.  Similarly, the support preferably has a specific surface area of between 800 and 1500 m 2 / m 3; and / or a mass / area ratio of less than or equal to 1200 g / m2.  By configuring the support so that the peripheral belt is in a horizontal position when the support is in free immersion, it promotes the low inertia of the support, while preventing a nesting of slats of several supports.  In one embodiment, the support is made of plastic / vegetable composite material.  In one embodiment, the support is obtained according to an injection method, in which process a mixture comprising at least one plastic resin and one organic vegetable filler is used to fill a mold of corresponding shape by injection under pressure, and wherein the vegetable organic filler is wood, and wherein the proportion of vegetable organic filler is substantially between 15 and 30% by weight.  F27287FRD1 [0022] Advantageously, the organic vegetable filler is a filler favoring the attachment of bacteria.  A preferred vegetable organic filler is of the cellulosic filler type, particularly wood.  By providing a plant organic filler substantially between 15 and 30% by weight, it is ensured to obtain a support having an optimal density for a wastewater treatment application.  The mixture can have a fluidity of substantially between 5 and 20g / 10 minutes at 190 ° C and under 2.16 kg.  Such fluidity parameters make it possible to ensure stability of the manufacturing process.  The mixture may also have a density substantially between 0.920 and 0.950 g / cm3, before injection, to obtain a support that does not float but does not flow either, with low inertia.  Other features and advantages of the present invention will emerge from the description given below with reference to the accompanying drawings which illustrate an embodiment having no limiting character, among which: - Figure 1 is a view of the side of a tank of a wastewater treatment device in which a support according to one embodiment of the invention can be used; FIG. 2 is a sectional view of the tank of FIG. FIG. 3 is a view of an overflow system in a wastewater treatment device in which a support according to one embodiment of the invention can be used; FIG. 4 is a view of a A usable aeration system of a wastewater treatment device in which a support according to one embodiment of the invention can be used; FIG. 5 is a schematic diagram of a water treatment process in which can be used a suppo According to an embodiment of the present invention, FIG. 6 illustrates an embodiment of a culture support according to the present invention; FIG. 7 illustrates another embodiment of a culture support according to the present invention; FIG. 8 illustrates another embodiment of a culture support according to the present invention; FIG. 9 is a block diagram of a method for obtaining a support according to an embodiment of the present invention; .  In the drawings, identical or similar elements are indicated with identical or similar reference numbers.  FIG. 1 shows a side view of a tank 2 of a wastewater treatment device 1 in which a support can be used according to one embodiment of the invention, and FIG. a sectional view of the tank of Figure 1.  The tank 2 is a one-piece tank with three compartments, comprising a settling chamber 10, for the settling of wastewater, a reaction compartment 20, for the biological treatment of wastewater, and a clarification compartment 30, for the clarification of the waters.  The decantation compartment 10 is provided with an inlet 11 for the arrival of waste water.  Preferably, the wastewater arrives by gravity flow in the settling compartment 10.  The clarification compartment 30 is provided with an outlet 31, for the evacuation of treated wastewater.  Between the settling compartment 10 and the reaction compartment 20 is a first partition wall 4, and between the reaction compartment 20 and the clarification compartment 30 is a second partition wall 6.  The first and second partition walls 4, 6 have upper ends on which is fixed a carrier rider 50, whose function will be explained in the following.  The tank 2 is preferably derived from a manufacturing process called roto-molding of a polymer material such as polyethylene.  The roto-molding of the monobloc tank makes it possible to guarantee the sealing of the first and second separating walls 4, 6.  F27287FRD1 [0032] The settling chamber 10 is provided to allow the decantation of wastewater, that is to say a separation of the materials contained in the wastewater, the heavier materials, such as mineral substances, falling on the bottom compartment, while the lightest materials, such as grease, remain on the surface.  The settling chamber 10 is dimensioned so as to have a lower volume V1, an intermediate volume V2, and a higher volume V3 said buffer volume.  The lower volume V1 is provided for the storage of heavy materials fallen to the bottom of the compartment during decantation.  Intermediate volume V2 corresponds to the expected volume of wastewater to be treated in current use.  The upper volume V3 is a buffer volume, normally provided to remain empty, allowing to have a space for an arrival of an exceptional volume of water, which makes it possible to absorb strong peaks in input as for example during a bathtub drain.  A transfer system 15 allows the transfer of wastewater after settling, freed from the heavier materials, from the settling compartment 10 to the reaction compartment 20.  In the illustrated embodiment, the transfer system 15 is a ventilation system, fixed by a system of clips 51 on the carrying rider 50.  The transfer system 15 comprises an inlet port 16 disposed in the settling compartment, and an outlet port 17 opening into the reaction compartment 20.  The input port 16 is arranged in the intermediate volume V2 of the settling compartment 10, that is to say away from the heavy materials.  The input port 16 is also preferably provided with a large floating filter grid.  The outlet port 17 is provided to open up the reaction compartment 20, above the maximum expected height of water volume.  This arrangement thus allows an installer to see if the first transfer system 15 is working properly, in the context of a maintenance operation for example.  F27287FRD1 [0037] In order to allow the biological treatment of the wastewater to be treated in the reaction compartment 20, fixing supports 7 are provided, allowing the fixation of bacterial flocs in the form of biofilm.  Preferred supports 70, 270, 370 are described below, with reference to FIGS. 6 to 8.  According to one embodiment of the invention, the supports are in free immersion in the reaction compartment 20.  In Figure 2, only two supports 7 are shown for illustrative purposes only.  Preferably, the supports occupy a maximum volume corresponding to 30% of the volume of the reaction compartment 20.  In order to ensure the aerobic and anoxic conditions enabling the organic filler to be digested and the nitrogen to be removed, an air diffuser system 22 is arranged in the compartment, to allow via a programmable controller the sequential aeration of the reaction compartment 20.  The air diffuser system 22 is fixed on the carrying rider 50, by a system of clips 52.  The air diffuser system 22 is controlled by a programmable controller (not shown in the figures) in a control cabinet.  A flow system 25 is provided to allow the transfer of the treated wastewater to the clarification compartment 30, preferably by gravity flow, and comprises an inlet port 26 disposed in the reaction compartment 20, and a output port 27 opening into the clarification compartment 30.  The flow system 25 is fixed on the carrying rider 50, by a fixing system type clips 53.  The flow system 25 comprises an overflow 66, arranged to hold the supports in the reaction compartment 20.  As seen well in FIG. 3, the overflow 66, in the embodiment of the invention, comprises an overflow body with a first longitudinal end 67 substantially in the shape of a horizontal T, with the inlet port 26, and a longitudinal end with a F27287FRD1 elbow 68 with the outlet port 27, provided to open by dipping into the clarification compartment 30.  The longitudinal end 67, arranged in the reaction compartment 20, comprises an upper branch 67b open with the inlet port 26, and a lower branch 67a provided with a pierced stopper 69, to prevent the supports of be leached to the clarification compartment 30.  Elbow 68 is arranged in the clarification compartment 30, Elbow 68 is pierced on its curved area of greater curvature, to allow a balancing of pressure at atmospheric pressure, to prevent the formation of plugs and promote the flow of water.  As seen in Figure 2, the elbow 68 of the overflow 66 opens into the clarification compartment 30, close enough to the bottom, not to disturb the clarified water strata before their discharge via the outlet 31, which is arranged in the upper part of the compartment 30, in order to evacuate the clarified water.  A recirculation system 40 recirculates residual sludge from clarification, from the clarification compartment 30 to the reaction compartment 20.  In the context of the invention, this is known as IFAS technology (Integrated Fixed-film Activated Sludge).  The recirculation system 40 is fixed on the carrier rider 50.  The recirculation system 40 comprises a ventilation system 42, seen clearly in FIG. 4.  The ventilation system 42 comprises a lower end 43, arranged at the bottom of the clarification compartment 30, to allow the recovery of residual sludge accumulated at the bottom of the clarification compartment 30, and an upper end 44, not shown in FIG. 4, opening into the reaction compartment 20.  For example, the lower end may be located between 5 and 10 cm above the bottom of the clarification compartment 30.  F27287FRD1 [0050] The lower end 43 is substantially inverted T-shaped, wherein the T axing a first longitudinal end 43a and a second longitudinal end 43b.  The longitudinal ends are bevelled toward the bottom of the compartment 30 to increase the amount of material to be recirculated to the reaction compartment 20.  An additional recirculation system 45 is also provided, for the transfer of second materials from the clarification compartment 30 to the settling compartment 20.  The additional recirculation system 45 comprises a ventilation system 46 having a lower end 47 in the clarification compartment 30, and an upper end 48, opening into the clarification compartment 10.  The lower end 47 is bent in the form of siphon, arranged at a higher level relative to the lower end 43 of the recirculation system, with respect to a bottom of the clarification compartment 30.  The additional recirculation system 45 advantageously provides security in case of failure of the recirculation system 40.  Otherwise, the additional recirculation system 45 makes it possible to maintain the supply of the bacterial flocs in the reaction compartment 20, the recirculated water being returned to the settling compartment 10.  The clarification compartment is also connected to an outlet which leads through a visit device for the sampling of the effluent.  Thus, the carrier rider 50 is configured to maintain the transfer system 15, the flow system 25 and the recirculation system 40, as well as the additional recirculation system and the diffuser system 22.  The carrier rider 50 comprises at least two clips 52, 53 configured to clip on respectively the upper ends of the first and second separating walls 4, 6, respectively.  Similarly, the fixing of the various systems on the carrier jumper 50 is preferably performed by F27287FRD1 clip systems, which are economical and easy to implement and which optionally enable the user to be guided during assembly and disassembly of the device [0057] In the illustrated embodiment, the compartments are arranged in succession and dimensioned so that the volume of the settling compartment is substantially equal to 45% of the volume of the reaction compartment, and the first transfer system is arranged to empty the decant compartment at about 50%.  This makes it possible to have a buffer volume of approximately 750 liters to absorb the strong points at the entrance as for example during the emptying of a bath.  In addition, the aeration systems and the aerator are controlled by a control unit, not shown, in a control cabinet.  The pipe diameter of the air systems and the aerator can be chosen to allow sufficient air flow.  For example, the hourly flow rate of aeration systems is typically designed to pass 900 liters of wastewater into the device per day, in normal use.  In known manner, the ventilation systems are managed using a system comprising an air compressor, solenoid valves, and the control cabinet.  Similarly, the aerator is also controlled by the control unit.  Pipes, of different diameter, allow to bring the air necessary for the operation of the aerator and ventilation systems.  A purification process according to the invention will be described below, with reference to Figure 5, and using the device described with reference to Figures 1 and 2, summarizing the features described before for the purification device, the positioning arrangement / support of aeraulic elements of a wastewater treatment device and culture media.  Any of the aforementioned features summarized here or not must be understood as being able to characterize the purification process.  The purification process begins with the decantation of wastewater, in step S1, which are fed into the settling compartment 10, via the inlet 11.  In step S2, the decanted wastewater is transferred from the settling compartment 10 to the reaction compartment 20.  For the transfer, the transfer system 15, comprising only aeraulic elements, is used.  An air flow system is more economical than an electromechanical submersible pump type system.  A step S3 of aerobic treatment in the reaction compartment 20 follows the transfer step.  The aerobic treatment step includes aeration and rest phases, alternately, to ensure aerobic and anoxic conditions allowing the digestion of the organic charges by the bacterial flocs fixed on the supports, immersed and in water. free suspension in the reaction compartment 20.  The arrival of decanted wastewater in the reaction compartment 10 raises the level of water in the reaction compartment 20, causing the flow of a portion of the treated water through the flow system 25. , passive, gravity, from the reaction compartment to a clarification compartment, in step S4.  The flow of a portion of the wastewater comprises a step S5 for maintaining bacterial flocs comprising a step of maintaining the supports in the reaction compartment 20, in particular via the overflow 26 designed to prevent leaching of the supports by free immersion in the reaction compartment.  A clarification step S6 then takes place in the clarification compartment 30, allowing the residual materials to fall back into the bottom of the clarification compartment 30.  The method also comprises a recirculation step S7, for the transfer of first materials from the clarification compartment 30 to the reaction compartment 20, carried out via the recirculation system 40.  An additional recirculation step S8 is also provided to return second materials from the clarification compartment 30 to the settling chamber 11, using additional recirculation system 40.  This step of F27287FRD1 additional recirculation 38 is provided in operation to maintain the flow of water and ensure the maintenance of the bacterial population who have, through the recirculation of water in the settling compartment, always what s 'feed.  This additional recirculation step makes it possible to overcome a possible failure in the recirculation stage, for example because of a failure of the recirculation system.  The transfer and recirculation steps are performed sequentially, so as to allow the different stages of decantation, biological reactions and clarification to have enough time to achieve.  Similarly, the alternate aeration steps in the reaction compartment can be controlled for a treatment of a predetermined tidal volume.  For example, a treatment capacity of 6 equivalent inhabitants can be envisaged, ie a daily hydraulic handling capacity of 900 liters.  Furthermore, it is intended to empty the settling chamber 10 to leave the upper volume V3 empty, so that the upper volume can leave empty space in the settling chamber for an arrival of an exceptional volume of water.  Using the above example of the daily processing capacity of 900 liters, the water treatment device and the process transfer steps can be adjusted to allow a buffer volume of 750 liters.  Thus, a transferred volume of 80 liters per hour can be provided between the settling compartment and the reaction compartment.  This is only a non-limiting example, which may vary, in other, depending on the dimensions of the different compartments of the tank 2, the target volumes to be treated, the arrangement of the transfer system.  A control cabinet comprising a control system can be used to adjust time parameters and / or injection diffusers and / or air flow systems.  The control systems are well known to those skilled in the art and will not be described in the present description.  F27287FRD1 [0073] Figure 6 illustrates a mounting bracket 70 according to one embodiment of the invention.  The fixing support 70 comprises a central plate 71, from which extend a plurality of first lamellae 74a, and at least one connecting plate 75a of lamellae, interconnecting lamellae of the plurality of first lamellae 74a, and second lamellae 76a extending substantially from the connecting plate 75a.  Symmetrically on either side of the central plate 71, a plurality of third strips 74b extend from the central plate, symmetrical to the plurality of first strips 74a, and a second connecting plate 75b connects between they slats of the plurality of third slats 74b.  Fourth lamellae 76b extending substantially from the second connecting plate 75b, symmetrical to the second lamellae 76a with respect to the central plate 71. .  In the embodiment shown, the connecting plates 75a, 75b are substantially parallel to the central plate 71.  This is only a non-limiting example.  The presence of connecting plates advantageously makes it possible to increase the specific surface area required for fixation and biofilm formation.  A peripheral belt 78 surrounds the support body.  The peripheral belt prevents the entanglement of lamellae of the support with lamellae of the same or similar support, and thus constitutes a means of anti-entanglement.  The support has a center of gravity such that the peripheral belt is in a horizontal position when the support is in free immersion.  An inter-lamellar space is at least equal to or greater than 10 mm, in order to prevent the different parts of the biofilm from touching and agglomerating with each other, a biofilm protection against inter-piece shocks and tearing that can result.  F27287FRD1 [0081] The support has a size of between 5 and 7 cm, which makes it possible to prevent the support 70 from escaping from a treatment tank such as the tank 2, which could reduce the flow rate of the pipes or block them, or even pollute the receiving environment of treated wastewater and especially deplete the biological reactor.  The support 70 has a specific surface area of between 800 and 1500 m 2 / m 3, in order to maintain an optimized number of supports inside the biological reactor.  Similarly, a mass / area ratio less than or equal to 1200 g / m2, optimizes the amount of raw material used.  The number of lamellae on the support 70 may vary, depending on the size of the support for example and / or the target specific surface.  The support is made of a mixture of organic materials or compound promoting the formation and adhesion of the biofilm on its surface.  The compound is characterized by a fluidity of between 5 and 20 g / lOmin at 190 ° C. and under 2.16 kg, making it possible to easily fill the thin strips by pressure injection, a material density of between 0.920 and 0.950 g / cm 2. cm3, which allows the piece not to sink but to stay between two waters to have an optimal efficiency under the effect of the bubbles generated by the aerator, and the addition of a vegetable organic load in the plastic resin and in particular wood in a proportion of between 15 and 30% by weight.  FIG. 7 illustrates another embodiment of a fastening support 270.  The fixing support 270 differs essentially from the fixing support 70 by the presence of a plurality of lugs 279.  The fixing support 270 comprises a central plate 271, from which extend a plurality of first lamellae 74a, and at least one connecting plate 275a of lamellae, interconnecting lamellae of the plurality of first lamellae 274a, and second lamellae 276a extending substantially from the connecting plate 275a.  F27287FRD1 [0089] Symmetrically on either side of the central plate 271, a plurality of third lamellae 274b extend from the central plate, symmetrical to the plurality of first lamellae 274a, and a second connecting plate 275b connects between them third lamellae of the plurality of third lamellae 274b.  Fourth lamellae 276b extending substantially from the second connecting plate 275b, symmetrical to the second lamellae, with respect to the central plate 271.  In the embodiment shown, the connecting plates 275a, 275b are substantially parallel to the central plate 271.  This is only a non-limiting example.  The presence of connecting plates advantageously makes it possible to increase the specific surface area required for fixation and biofilm formation.  A peripheral belt 278 surrounds the support body.  The peripheral belt 278 prevents the entanglement of lamellae of the support with lamellae of the same or similar support, and thus constitutes an anti-entanglement means. The peripheral belt 278 is provided with lugs 279, which are arranged at intervals along the peripheral belt 279.  The lugs 279 are oriented towards the inside of the fixing support 270, between the plurality of lamellae.  Advantageously, the lugs 279 allow easy demolding of the mounting bracket 270, when the mounting bracket 270 is obtained by injection.  FIG. 8 illustrates a fixing support 370 according to another embodiment of the invention.  The mounting bracket 370 essentially differs from the mounting brackets 70, 270 shown in Figures 6 and 7 in that it does not have connecting plates.  The fixing support 370 comprises a central plate 371, from which extend a plurality of first lamellae 374a, and a plurality of second lamellae 376a.

F27287FRD1 [0096] Symmetrically on either side of the central plate 271, a plurality of third lamellae 374b extend from the central plate, symmetrical to the plurality of first lamellae 374a. Fourth lamellae 376b extend substantially from the central plate 371, symmetrical to the plurality of second lamellae 376a. In the embodiment shown, the first strips 374a are parallel to each other. The second lamellae 376a are also parallel to each other. Similarly, by symmetry, the third strips 374b are parallel to each other. The fourth lamellae 376b are also parallel to each other. The fixing support 370 comprises a second central plate 372, substantially perpendicular to the central plate 371. In FIG. 8, the first plates 374a are substantially symmetrical with the second plates 376a, with respect to the second central plate. 372. Similarly, the third lamellae 374b are symmetrical with the fourth lamellae 376b, with respect to the second central plate 372. In the embodiment illustrated, the first lamellae 374a are substantially symmetrical with the second lamellae 376a, on the one hand, and other of the second central plate 372, and the third lamellae 374b are symmetrical with the fourth lamellae 376b, with respect to the second central plate 372. In an alternative, the first and second lamellae, respectively the third and fourth lamellae, may be parallel to each other. In yet another embodiment, the first and second lamellae, respectively the third and fourth lamellae, may be unsymmetrical. [00101] A peripheral belt 378 surrounds the support body. The peripheral belt 378 prevents the entanglement of lamellae of the support with lamellae of the same or similar support, and thus constitutes an anti-entanglement means F27287FRD1 [00102] The peripheral belt 378 of the support 370 does not have any pins. However, in an alternative embodiment, the belt 378 could also have pins, to facilitate demolding during the manufacture of the support. [00103] A method of manufacturing a bacterial fixing support is described with reference to FIG. 9. The manufacturing process is aimed at the manufacture of a bacterial floc fixing support having a support body and spaced lamellae and having a shock resistance and a complex geometry, such as the fixing brackets of FIGS. 6 to 8. [00104] The method comprises the step S21 of injecting under pressure a mixture comprising at least one plastic resin and one vegetable organic filler, in a mold of a shape corresponding to the shape of the support to be obtained. The organic vegetable filler is of the cellulosic type, in particular wood, and the plastic resin is preferably of the polypropylene type. A hard type of wood having a hardness substantially between 2.60 to 4.5 in the Brinell hardness test, and a density generally between 550 and 800 kg / m3 is preferred. The proportion of vegetable organic filler is substantially between 15 and 30% by weight. This proportion makes it possible to stabilize injection parameters, which are difficult to stabilize when the percentage of vegetable load is high. The mixture has a fluidity of substantially between 5 and 20 g / 10 minutes at 190 ° C. and under 2.16 kg. The mixture has a density of substantially between 0.920 and 0.950 g / cm3. This makes it possible to obtain a fixing support that can be used in free immersion, that is to say that the support thus obtained will not float but will not flow either, In other words, a support obtained by injection a mixture of density between 0.920 and 0.950 g / cm3 can be maintained in a volume of water, without sinking and without going back to the surface. Such a support can be used in the reaction compartment of the tank 2 described with reference to FIGS. 1 and 2. F27287FRD1 Injection molding processes are well known to those skilled in the art, it is sufficient to indicate that the peculiarity of a method of manufacturing a culture support consists in the fact of using a plastic resin and a vegetable organic filler. Indeed, in the prior art, the supports were instead made from exclusively plastic material for reasons of non-putrefaction or non-perishability. The few attempts to obtain culture supports comprising materials of vegetable organic quality are limited to pieces of simple geometry, mostly obtained by extrusion. This invention is not limited to the embodiment described above but encompasses all variants. In particular, a feature illustrated and / or described in combination with other features may be provided independently or in combination with other features illustrated independently or in combination with other features and respectively independently or in arbitrary combination. F27287FRD1

Claims (9)

REVENDICATIONS1. A bacterial attachment support (70) comprising a support body with a plurality of spaced lamellae (72), at least two lamellae (74a) of the plurality of lamellae having substantially parallel ends, the support body (71) having an anti-entanglement means (78) of the carrier with an identical carrier or the like, wherein the anti-entanglement means comprises a peripheral belt (78) adapted to prevent entanglement of carrier slats with slats of a carrier identical or similar. The bacterial attachment support of claim 1, wherein an inter-lamellar space is at least 10 mm or greater. 3. Support according to any one of claims 1 to 2, comprising a central plate (71), from which extend a plurality of first lamellae (74a), and at least one connecting plate (75a) lamellae interconnecting lamellae of the plurality of first lamellae (74a) and second lamellae (76a) extending substantially from the connector plate (75a). 4. Support according to claim 3, comprising a plurality of third strips (74b), extending from the central plate (71) and symmetrical on either side of the central plate (71) relative to the plurality of first lamellae (74a), a second connecting plate (75b), interconnecting lamellae of the plurality of third lamellae (74b), and fourth lamellae (76b) extending substantially from the second connecting plate (75b). 5. Support according to any one of claims 1 to 2, comprising one or more of: - a skeleton structure in the form of one or more rings; a skeleton structure comprising at least one central plate from which the lamellae extend, symmetrically on either side of the plate, at least one element connecting the free ends of the lamellae. F27287FRD1 6. Support according to any one of claims 1 to 5, comprising: a size of between 5 and 7 cm; a specific surface area of between 800 and 1500 m 2 / m 3; and / or - a mass / area ratio of less than or equal to 1200 g / m2. 7. Support according to any one of claims 1 to 6, configured for the peripheral belt is in a horizontal position when the support is in free immersion. 8. Bacteria fixation support according to one of the preceding claims, wherein the support is made of plastic / vegetable composite material. 9. Support according to claim 8, wherein the support is obtained by an injection method, wherein a mixture comprising at least one plastic resin and a vegetable organic filler is used to fill a mold of corresponding shape by injection under pressure, and wherein the vegetable organic filler is wood, and wherein the proportion of vegetable organic filler is substantially between 15 and 30% by weight. F27287FRD1