AU2025228130B2

AU2025228130B2 - Diffuser

Info

Publication number: AU2025228130B2
Application number: AU2025228130A
Authority: AU
Inventors: Gerald GLANINGER; Junichi KAGOROKU
Original assignee: Aquaconsult Anlagenbau GmbH
Current assignee: Aquaconsult Anlagenbau GmbH
Priority date: 2024-02-27
Filing date: 2025-02-27
Publication date: 2026-04-09
Anticipated expiration: 2045-02-27
Also published as: EP4661997A1; WO2025179321A1; AT527914A4; AU2025228130A1; AT527914B1; CN121568780A

Abstract

A diffuser (1), preferably strip diffuser, for aerating a liquid, preferably wastewater, comprising: a preferably elongate hollow-profile main part (5), a gas-supply device for supplying a gas, a gas-permeable membrane (9) for dispensing the gas, and a membrane-retaining part (10) with a bearing surface (11) for the membrane (9), the membrane-retaining part (10) being connected to the hollow-profile main part (5) via a releasable connection (16).

Description

WO 2025/179321 A1

Veröffentlicht: mit internationalem Recherchenbericht (Artikel 21 Absatz

- 3)

Diffuser

Technical Field

This disclosure is related to aerators, devices using the aera- tors and methods of mounting the aerators.

Background 2025228130

An aerator is known from AT 506 717, with which gas bubbles are introduced into a wastewater or wastewater basins for the bio- logical purification of wastewater. When gassing or aerating the wastewater, it is important to supply the supplied gaseous oxy- gen to the wastewater in the form of fine gas bubbles in order to create the largest possible exchange area between the gas bubbles and the wastewater. For this purpose, the aerator has a membrane with small through-holes, with which the gas bubbles are dispensed to the wastewater. The membrane is attached to the side regions of a base body with the aid of locking bodies in groove-shaped receptacles. The base body has side parts which can be pressed outwards in order to remove the membrane with the locking bodies from the clamping grooves.

WO 2015/164900 discloses a mounting device with which the strip aerator of WO 2009/132374 can be installed in a simple manner at the bottom of the settling basin. For this purpose, the mounting device comprises an elastically deflectable retaining web, which can be connected to the side wall of the base body. During mounting of the aeration element, the retaining web may be pressed elastically outward to allow the aeration element to be arranged in the mounting element. Accordingly, the aeration ele- ment may be dismounted. With this mounting device, the mounting and dismounting of the aerator can be simplified significantly. However, the entire aerator, including the base profile and the gas connection tube, must always be replaced. Thus, the replace- ment is associated with high costs.

On the other hand, it is very difficult to replace the membrane without the base body on site, as skilled personnel and special tools are required. In the event of improper replacement, the

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quality may also suffer.

WO 2021/140151 A9 describes a strip aerator which has an upper film section and a lower film section which are connected to one another in a gas-tight manner on their longitudinal sides, so that a gas-carrying chamber is formed between the film sections. The upper film section has a plurality of openings that allow gas to pass from the air-carrying chamber into the environment. 2025228130

The strip aerator is mounted on a retaining plate. The aerator assembly made of strip aerator and retaining plate may be at- tached to a bottom or a wall of an aerator basin. In order to connect the strip aerator to the retaining plate, keders are provided which extend over the entire length of the strip aera- tor. The keders can be inserted into attachment rails on the re- taining plate. In order to seal off the two film sections in a completely gas-tight manner and thus to cause the gas to exit from the gas-carrying chamber only through the openings in the upper film section, the film sections are likewise connected to one another in a gas-tight manner at their end faces. This end face connection can be achieved via an attached end profile, which encloses the two film sections between them in a gas-tight manner. In order to be able to apply the gas to the gas-tight chamber, the strip aerator has a connecting tube on one of the end faces. As a result, no support body is provided in the gas- carrying chamber or in the subchambers themselves. In this prior art, a support body for the strip aerator is thus dispensed with. Thus, the known strip aerator can be wound up due to its elastic resilience. However, dispensing with the stable support body has the disadvantage that the connecting tube is connected directly to the film sections. As a result, mechanical forces are transmitted from the air supply tubes, in particular by wa- ter currents, to the film sections that constitute the most sen- sitive part of the aerator. This creates a potential vulnerabil- ity. Furthermore, the lower film section is not surrounded by flowing water, as a result of which it can be significantly heated by the introduced, usually hot air, which results in a reduction in mechanical strength. During mounting, the known strip aerator is threaded into the attachment rails on the re- taining plate. Although this design allows the membrane to be replaced, threading the windable strip aerator into the

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attachment rails is complicated. Furthermore, there must be suf- ficient space in front of the end face of the retaining plate to be able to attach the aerator to the end face of the retaining plate. Finally, in practice, a tool for changing the aerator is also required. 22304903_1 (GHMatters) P127496.AU

Summary 2025228130

According to an aspect, disclosed is an aerator, in some embodi- ments a strip aerator, for aerating a liquid, in some embodi- ments wastewater, comprising: in some embodiments an elongated hollow profile base body, a gas supply device for supplying a gas, a gas-permeable membrane for dispensing the gas.

According to a further aspect, disclosed is an aerator device comprising: an aerator, a mounting bracket with which the aerator is mounted, advan- tageously releasably, at the site of use, advantageously in an aeration basin of a wastewater treatment plant.

According to a further aspect, disclosed is a wastewater treat- ment plant comprising: an aeration basin, an aerator mounted in the aeration basin.

According to a further aspect, disclosed is a method for mount- ing the aerator.

The present invention may alleviate or eliminate at least some of the disadvantages of the prior art. The present invention may provide a strip aerator in which the replacement of the aerator membrane can be carried out with little effort without having to give up the stable basic construction of the aerator or without impairing the sealing of the membrane.

Disclosed is an aerator according to claim 1, an aerator device according to claim 10, a wastewater treatment plant according to claim 11 and a method according to claim 12. Embodiments of the

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invention are specified in the dependent claims.

According to a further aspect disclosed is an aerator, in some embodiments a strip aerator, for aerating a liquid, in some em- bodiments wastewater, comprising: in some embodiments an elon- gated hollow profile base body, a gas supply device for supply- ing a gas, a gas-permeable membrane for dispensing the gas, wherein a membrane retaining part with a support surface for the 2025228130

membrane, wherein the membrane retaining part is connected to the hollow profile base body via a releasable snap connection.

According to a further aspect disclosed is an aerator device comprising an aerator described above, a mounting bracket with which the aerator is mounted, in some embodiments releasably, at the site of use, in some embodiments in an aeration basin of a wastewater treatment plan.

According to a further aspect disclosed is a wastewater treat- ment plan comprising an aeration basin and an aerator described hereinabove.

According to a further aspect disclosed is a method of mounting the aerator described above, comprising the steps of: providing the hollow profile base body and the membrane retaining part with the membrane separately from each other, releasably con- necting the membrane retaining part together with the membrane to the hollow profile base body.

In some embodiments, the aerator has a membrane retaining part with a support surface for the membrane. The membrane retaining part is connected to the hollow profile base body via a releasa- ble connection.

The membrane is attached to the membrane retaining part, which has the support surface for the membrane on the upper side. The hollow profile base body and the membrane retaining part are in the separated state before mounting. The membrane retaining part together with the membrane attached thereto is reversibly re- leasable, i.e. can be connected to the hollow profile base body repeatedly and substantially without damage. For the membrane

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change, the releasable connection is released so that the mem- brane retaining part together with the membrane can be removed. Subsequently, a membrane retaining part with a membrane may be provided, which is mounted on the hollow profile base body via the releasable connection. During the dismounting of the mem- 22304903_1 (GHMatters) P127496.AU

brane retaining part with the membrane in the mounted state, the hollow profile base body could remain at the site of use, i.e. in some embodiments in an aeration basin of a wastewater treat- 2025228130

ment plant. Advantageously, only the membrane retaining part with the membrane has to be changed, as a result of which the material expenditure can be significantly reduced in comparison with the replacement of the aerator with the hollow profile base body. It is also advantageous if the membrane retaining part to- gether with the membrane is provided by the manufacturer as a replacement component. As a result, the tightness of the connec- tion between the membrane and the membrane retaining part can always be ensured. This tight connection is already present when the membrane retaining part together with the membrane is mounted. Thus, it is not necessary to achieve the sealing of the membrane only with the mounting. The membrane retaining part and the hollow profile base body are dimensionally stable. This means that the membrane (with respect to the unloaded state without gas supply) is attached to the membrane retaining part in a predetermined shape. The membrane retaining part may be made of a plastic, in some embodiments polyvinyl chloride (PVC). Depending on the design, the hollow profile base body may be made of a further plastic. Due to the dimensionally stable de- sign of the membrane retaining part and the hollow profile base body, mounting maybe facilitated compared to windable aerators, since the releasable connection can be reliably and stably pro- duced and separated. The hollow profile base body allows the me- chanical stability of the aerator. For this purpose, the hollow profile base body may be designed as an extruded profile. A gas supply channel, through which the gas, in particular air, can be supplied, is formed in the interior of the gas supply device. The hollow profile base body may have a cavity, in some embodi- ments open towards the end face, into which the gas supply de- vice is inserted. The membrane retaining part may be designed to be slimmer than the hollow profile base body, so that the mem- brane retaining part has a lower maximum height, i.e. extension

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in the vertical direction, than the hollow profile base body.

In the connected state of use, the membrane retaining part may extend substantially over the entire length of the hollow pro- file base body. Thus, the membrane (with respect to the state without application of the gas) rests substantially over its en- tire surface against the support surface. When the gas supply is established, the membrane bulges up from the support surface un- 2025228130

der the pressure of the gas.

Depending on the design, the membrane may be made of a plastic, in some embodiments polyurethane. The membrane has a plurality of gas passage openings for gas passage into the liquid.

In the mounted state of use, the aerator is may be mounted on a sole of an aeration basin. The aerator may be in a substantially horizontal state.

For purposes of this disclosure, the location and direction in- dications, such as “top,” “bottom,” “vertical,” “horizontal,” refer to an intended state of use of the aerator in a horizontal arrangement at a horizontal site of use, particularly in an aer- ation basin. If the aerator is to be used in a different posi- tion, the location and direction information must be transmitted accordingly.

In an embodiment, the membrane retaining part and the hollow profile base body are connected to one another via a releasable snap connection. For this purpose, the membrane retaining part and/or the hollow profile base body has at least one elastically deformable snap connection element. When the snap connection is produced and/or released, the at least one snap connection ele- ment of the hollow profile base body and/or of the membrane re- taining part is temporarily elastically deformed, so that the membrane retaining part, together with the membrane attached thereto, reaches the snapped-in state on the hollow profile base body. In the snapped state of the membrane retaining part into the hollow profile base body, the at least one snap connection element of the hollow profile base body and/or of the membrane retaining part has returned to its initial position due to its

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elasticity. As a result, the membrane retaining part is held non-positively and/or positively on the hollow profile base body. In some embodiments, the snap connection can be produced and/or released without tools. The snap connection is reversi- ble, i.e. repeatedly and substantially damage-free, releasable. In this embodiment, the membrane change can be carried out par- ticularly easily and quickly. For this purpose, one membrane re- taining plate together with the membrane can be separated from 2025228130

the hollow profile base body by releasing the snap connection and then the other membrane retaining plate together with the membrane can be snapped into the hollow profile base body.

In an embodiment, the hollow profile base body comprises at least one elastically deformable snap connection bar, in some embodiments on one of the opposite longitudinal sides of the hollow profile base body, for the snap-fitting of an edge, in some embodiments a longitudinal edge, of the membrane retaining part. When attaching the membrane retaining plate together with the membrane, the snap connection bar can be elastically de- formed, in some embodiments deflected to the side, in particular to the outside, until the membrane retaining part is snapped onto the hollow profile base body. In the snapped-in state, the snap connection bar has returned to its initial position due to its elasticity, wherein the membrane retaining part may be held on the hollow profile base body by a positive fit.

In the embodiment of the aerator as a strip aerator, the snap connection bar may extend on one of the two longitudinal sides of the hollow profile base body, which extend parallel to the longitudinal direction of the hollow profile base body, i.e. parallel to the main extension direction of the hollow profile base body. In this embodiment, the snap connection bar may ex- tend substantially parallel to the longitudinal direction. In some embodiments, the snap connection bar may be arranged sub- stantially vertically.

In an embodiment, the at least one snap connection bar, in some embodiments at the upper end in each case, has an inwardly di- rected retaining protrusion for securing the membrane retaining part against lifting off the hollow profile base body. In some

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embodiments, the retaining protrusion may be substantially tri- angular, viewed in the vertical cross section perpendicular to the longitudinal direction of the hollow profile base body.

In an embodiment, the hollow profile base body has two elas- tically deformable snap connection bars, in some embodiments on opposite longitudinal sides of the hollow profile base body, for the snap-fitting of edges, in some embodiments of opposite lon- 2025228130

gitudinal edges, of the membrane retaining part. In some embodi- ments, the two snap connection bars are arranged on the opposite longitudinal sides of the hollow profile base body. The two snap connection bars may be formed symmetrically with respect to a vertical center plane of the aerator. Advantageously, during mounting, the membrane retaining part may be attached to each of the two snap connection bars and pressed into the respective other snap connection bar in order to produce the snap connec- tion. Thus, mounting is simplified and mounting errors can be reliably avoided.

In an embodiment, the edges, in some embodiments the opposite longitudinal edges, of the membrane retaining part are connected to the snap connection bars in the mounted state, wherein one edge, in some embodiments longitudinal edge, of the membrane re- taining part is connected to the one snap connection bar and the other edge, in some embodiments longitudinal edge, of the mem- brane retaining part is arranged above the other snap connection bar in an intermediate mounting or dismounting position, so that the membrane retaining part can be transferred into the mounted state on the hollow profile base body by pressing in the other edge, in some embodiments the longitudinal edge, into the other snap connection bar.

In an embodiment, the membrane retaining part has a gas supply opening through which the gas can pass under the membrane. For this purpose, the gas supply opening of the membrane retaining part can be connected to the gas supply device. The gas supply device may have a connection part, which may be arranged in the gas supply opening of the membrane retaining part with a sub- stantially precise fit. Thus, the gas from the gas supply chan- nel can flow through the gas supply opening of the membrane

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retaining part under the membrane, lift the membrane from the support surface and pass through the openings of the membrane into the liquid, in particular into the wastewater.

In an embodiment, the gas supply device has a gas supply tube, which may protrude outwards (i.e. away from the centre of the aerator) beyond one of the end faces of the membrane retaining part and the hollow profile base body. The gas supply tube may 2025228130

be connected to the connection part by means of which the gas is guided through the membrane retaining part under the membrane (i.e. to the side of the membrane facing away from the wastewater).

The gas supply device may be inserted into a cavity on the end face of the hollow profile base body. Thus, the gas passes from the gas supply channel of the hollow profile base body through the gas supply opening of the membrane retaining part to the membrane and through the openings of the membrane into the envi- ronment, in particular into the liquid of the aeration basin.

The cross-section perpendicular to the longitudinal direction, i.e. with respect to the mounted state of use of the vertical section, of the hollow profile base body may be substantially constant over its length. The cross section of the membrane re- taining part perpendicular to the longitudinal direction, i.e. with respect to the mounted state of use of the vertical sec- tion, may also be substantially constant over its length.

In an embodiment, a membrane retaining plate is provided as the membrane retaining part. On the upper side, the membrane retain- ing plate can have a flat support surface for the membrane, which support surface is arranged horizontally in the mounted state of use. Depending on the design, the membrane retaining plate may have a main section with a substantially constant wall thickness and two side sections which are formed with greater wall thicknesses than the main section and can be connected to the hollow profile base body. In addition, the side sections can hold the edges of the membrane.

In an embodiment, the membrane is connected to the membrane

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retaining part via at least one keder connection. In some embod- iments, keder connection may be provided on each of the opposite longitudinal edges of the membrane retaining part. For this pur- pose, the membrane can be wrapped around the respective longitu- dinal edge of the membrane retaining part and each be held in a keder groove with a keder.

In an embodiment, the keder groove is delimited on the outside, 2025228130

i.e. with respect to the mounted state of use on the side of the respective snap connection bar, by a web. In some embodiments, the web may be elastically deflectable in the arrangement of the keder for attaching the membrane. In the mounted state of use on the hollow profile base body, the outer side of the web rests against the inner side of the snap connection bar. This prevents the deflection of the web during use, so that the membrane is securely held in the keder groove.

In the method according to the invention for mounting the aera- tor, at least the following steps are carried out: providing the hollow profile base body and the membrane re- taining part with the membrane separately from each other, i.e. in the separated state, connecting the membrane retaining part, together with the membrane attached thereto, to the hollow profile base body by establishing the releasable connection, in some embodiments the snap connection, so that the aerator is present in the mounted state.

During mounting, the following steps are in some embodiments carried out: arranging the membrane retaining part in an intermediate mounting position, wherein one edge, in some embodiments longi- tudinal edge, of the membrane retaining part is connected to a snap connection bar of the hollow profile base body and the other edge, in some embodiments longitudinal edge, of the mem- brane retaining part is arranged above an opposite snap connec- tion bar of the hollow profile base body, clicking in the other edge, in some embodiments longitudinal edge, into the other snap connection bar, so that the membrane retaining part is held on the hollow profile base body in the

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mounted state.

Brief Description of Drawings

The invention is explained in more detail below with reference to an exemplary embodiment illustrated in the drawings.

FIG. 1A shows a strip aerator according to the invention without 2025228130

a membrane.

FIG. 1B shows the strip aerator of FIG. 1A in an exploded view.

FIG. 2 shows the strip aerator of FIG. 1 with a membrane, but without a gas supply device.

FIGS. 3 to 5 illustrate the mounting of the strip aerator.

Detailed Description

FIG. 1A and FIG. 1B show an aerator 1, here a strip aerator, for aerating a liquid, preferably wastewater. The aerator 1 is mounted for installation in an aeration basin 2 (shown symboli- cally) of a wastewater treatment plant 3. For this purpose, the aerator can be mounted on the bottom 4 of the aeration basin 2 with a mounting bracket (not shown). Depending on the design, several identical aerators may be attached in the aeration ba- sin, preferably parallel to one another.

The aerator 1 has a hollow profile base body 5 with a longitudi- nal direction 6 (cf. FIG. 2), which is the direction of the longest extension of the hollow profile base body 5. In plan view, the aerator 1 is substantially rectangular. The aerator 1 has a gas supply channel 7, which is formed in the interior of a gas supply device 8. For this purpose, the gas supply device 8 has a gas supply tube 8A in the example shown, which is supplied with gas, in particular air, during operation.

As can be seen from FIG. 2, the gas is dispensed into the liquid via a gas-permeable, for example perforated, membrane 9. The membrane 9 is located at the top of the aerator 1.

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According to the invention, the aerator 1 has a membrane retain- ing part 10 which is separated from the hollow profile base body 5 and to which the elastic membrane 9, i.e. one which can be de- formed under gas pressure, is attached. The membrane retaining 22304903_1 (GHMatters) P127496.AU

part 10 extends at least over the entire length, i.e. extension in the longitudinal direction 6, of the hollow profile base body 5. In the example shown, the membrane retaining part 10 pro- 2025228130

trudes slightly beyond the hollow profile base body, so that end clamps can be mounted on the end faces of the membrane retaining part. On the upper side, the membrane retaining part 10 has a support surface 11, which is flat in the example shown and is arranged substantially horizontally, against which the membrane 9 rests over the entire surface in the unloaded state, i.e. without gas supply. The longitudinal edges of the membrane 9 are held on the membrane retaining part 10 via keder connections 12. To form the keder connections 12, the longitudinal edges of the membrane 9 are folded around longitudinal edges 13 of the mem- brane retaining part 10, guided in keder grooves 14 and fixed with keders 15. In the exemplary embodiment shown, a membrane retaining plate is provided as the membrane retaining part 10, said membrane retaining plate having a smaller height, prefera- bly a multiple of a smaller height, i.e. extending in the verti- cal direction, than the hollow profile base body 5.

The membrane retaining part 10 has a through-hole 10A (cf. FIG. 1) in which a connecting part of the gas supply device is seated. Thus, the gas can pass through the gas supply channel from the gas supply tube 8A through the connection part in the through-hole 10A of the membrane retaining part 10 under the membrane 9 and be dispensed into the liquid via the openings of the membrane 9.

According to the invention, the membrane retaining part 10 is connected to the hollow profile base body 5 via at least one re- versibly releasable connection 16, here at least one snap con- nection. In the exemplary embodiment shown, the hollow profile base body 5 has two elastically deformable snap connection bars 17, which form the opposite longitudinal sides of the hollow profile base body 5. The snap connection bars 17 can be

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elastically deflected laterally outward, so that the longitudi- nal edges 13 of the membrane retaining part 10 can be snapped into the snap connection bars 17 of the hollow profile base body 5 on the inside. In addition, a web or a groove wall of the mem- brane retaining part 10 that delimits the keder groove 14 is blocked from deflecting outward, so that the membrane 9 is se- cured against slipping out of the keder groove 14. At the upper ends, the snap connection bars 17 each have an inwardly directed 2025228130

retaining protrusion 18 for securing the membrane retaining part 10 against lifting off the hollow profile base body 5.

FIG. 3 to FIG. 5 show the mounting of the membrane retaining part 10 on the hollow profile base body 5.

According to FIG. 3, the membrane retaining part 10 and the hol- low profile base body 5 are provided in the separated state. The membrane 9 is already fixed to the membrane retaining part 10 via the keder connections 12.

According to FIG. 4, the membrane retaining part 10 is posi- tioned above the hollow profile base body 5.

According to FIG. 5, in an intermediate mounting position, the membrane retaining part 10 is attached to the inside of one of the two snap connection bars 17. The lateral longitudinal edge of the membrane retaining part 10 is received with a substan- tially precise fit in the recess, which is formed by the retain- ing protrusion 18, the upstanding section of the snap connection bar 17 and a bottom profile part 19 of the hollow profile base body 5. In the intermediate mounting position, the membrane re- taining part 10 is arranged obliquely to the horizontal. The op- posite longitudinal edge of the membrane retaining part 10 is located above the other snap connection bar 17. By pressing in the direction of arrow 20, the longitudinal edge of the membrane retaining part 10, which is initially located above the hollow profile base body 5, is pressed into the snap connection bar 17 below. By elastic deflection laterally outward, the longitudinal edge 13 of the membrane retaining part 10 can pass the retaining protrusion 18, so that the membrane retaining plate 10 reaches the mounted state on the hollow profile base body 5, which is

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shown in FIG. 1 and FIG. 2.

It is to be understood that, if any prior art is referred to herein, such reference does not constitute an admission that the prior art forms a part of the common general knowledge in the art, in Australia or any other country.

In the claims which follow and in the preceding description of 2025228130

the disclosure, except where the context requires otherwise due to express language or necessary implication, the word “comprise” or variations such as “comprises” or “comprising” is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the disclosure.

List of reference numerals:

1 aerator 2 aeration basin 3 wastewater treatment plant 4 bottom 5 hollow profile base body 6 longitudinal direction 7 gas supply channel 8 gas supply device 8A gas supply tube 9 membrane 10 membrane retaining part 10A through-hole 11 support surface 12 keder connection 13 longitudinal edge 14 keder groove 15 keder 16 releasable connection 17 snap connection bar 18 retaining protrusion 19 bottom profile part 20 arrow direction

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Claims

Claims:

1. An aerator, preferably strip aerator, for aerating a liquid, preferably wastewater, comprising: a preferably elongated hollow profile base body, a gas supply device for supplying a gas, a gas-permeable membrane for dispensing the gas, wherein, 2025228130

a membrane retaining part with a support surface for the membrane, wherein the membrane retaining part is connected to the hol- low profile base body via a releasable snap connection.

2. The aerator according to claim 1, wherein the hollow profile base body comprises at least one elastically deformable snap connection bar, preferably on one of the opposite longitudinal sides of the hollow profile base body, for the snap-fitting of an edge, preferably a longitudinal edge, of the membrane retain- ing part.

3. The aerator according to claim 2, wherein the at least one snap connection bar, preferably at the upper end in each case, has an inwardly directed retaining protrusion for securing the membrane retaining part against lifting off the hollow profile base body.

4. The aerator according to claim 3, wherein the hollow profile base body comprises two elastically deformable snap connection bars, preferably on opposite longitudinal sides of the hollow profile base body, for the snap-fitting of edges, preferably of opposite longitudinal edges, of the membrane retaining part.

5. The aerator according to claim 4, wherein the edges, prefera- bly the opposite longitudinal edges, of the membrane retaining part are connected to the snap connection bars in the mounted state, wherein one edge, preferably longitudinal edge, of the membrane retaining part is connected to the one snap connection bar and the other edge, preferably longitudinal edge, of the membrane retaining part is arranged above the other snap connec- tion bar in an intermediate mounting or dismounting position, so

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that the membrane retaining part can be transferred into the mounted state on the hollow profile base body by pressing in the other edge, preferably longitudinal edge, against the other snap connection bar.

6. The aerator according to any one of claims 1 to 5, wherein the membrane retaining part has a gas supply opening which is connected to the gas supply device. 2025228130

7. The aerator according to any one of claims 1 to 6, wherein the gas supply device has a gas supply tube which preferably protrudes beyond one of the end faces of the membrane retaining part and of the hollow profile base body.

8. The aerator according to any one of claims 1 to 7, wherein a membrane retaining plate is provided as the membrane retaining part.

9. The aerator according to any one of claims 1 to 8, wherein the membrane is connected to the membrane retaining part via at least one keder connection.

10. An aerator device comprising: an aerator according to any one of claims 1 to 9, a mounting bracket with which the aerator is mounted, pref- erably releasably, at the site of use, preferably in an aeration basin of a wastewater treatment plant.

11. A wastewater treatment plant comprising: an aeration basin, an aerator according to any one of claims 1 to 9, which is mounted in the aeration basin.

12. A method of mounting the aerator according to any one of claims 1 to 9, comprising the steps of: providing the hollow profile base body and the membrane re- taining part with the membrane separately from each other, releasably connecting the membrane retaining part together with the membrane to the hollow profile base body.

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13. The method of claim 12, wherein: arranging the membrane retaining part in an intermediate mounting position, wherein one edge, preferably longitudinal edge, of the membrane retaining part is connected to a snap con- nection bar of the hollow profile base body and the other edge, preferably longitudinal edge, of the membrane retaining part is arranged above an opposite snap connection bar of the hollow profile base body, 2025228130

clicking in the other edge, preferably longitudinal edge, into the other snap connection bar, so that the membrane retain- ing part is held on the hollow profile base body in the mounted state.

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