Process to purify wastewater
Patent Information
- Application Number
- BR112021021545
- Authority / Receiving Office
- BR · BR
- Patent Type
- Patents
- Current Assignee / Owner
- Publication Date
- 2026-08-11
Smart Images
Figure 00000026_0000 
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Abstract
Description
1 / 21 PROCESS FOR PURIFYING WASTEWATER
[001] The present invention relates to a wastewater purification apparatus and to a wastewater purification process, particularly that known as the RBS process.
[002] Document EP 1,132,348 B1 describes a wastewater purification apparatus and a wastewater purification process for biological wastewater treatment. The wastewater purification apparatus comprises an elongated tank that is divided by means of partition walls into a series of treatment sections. Wastewater purification takes place in the treatment sections according to what is known as the “Sequential Batch Reactor” (RBS) process. For this purpose, the wastewater is brought into contact, in the first treatment section, with activated sludge. The suspension formed with the wastewater and the activated sludge is then aerated, particularly in the second treatment section. Finally, the suspension is neither aerated nor moved in the third treatment section. The treated water is removed in the form of supernatant by means of a settling tank. The RBS process is normally carried out in batches.
[003] In the wastewater purification apparatus described in EP 1,132,348 B1, the movable partition walls are made of flexible, waterproof film. This film is not particularly durable. In order to transfer wastewater from one treatment section to the next, pumps and lines are required. The treatment efficiency of the known wastewater purification apparatus is not very high. Petition 870240074974, dated 02 / 09 / 2024, page 6 / 35 2 / 21
[004] The object of the present invention is to overcome the disadvantages of the prior art. In particular, an apparatus and process for purifying wastewater are described which allow for more efficient purification of wastewater. The apparatus and process for purifying wastewater should also allow, in particular, for continuous purification of wastewater.
[005] This object is achieved by the features of claims 1 and 8. Convenient embodiments of the present invention will become clear from the features of the dependent claims.
[006] According to the present invention, a wastewater purification apparatus is proposed for purifying wastewater, comprising: - an elongated tank that, on its narrow first side, has an inlet flow for wastewater feeding; - first vertical agitator with first hyperboloid agitator body fixed to a first vertical agitator shaft, wherein the first vertical agitator is provided in the first treatment section after the inlet flow on the first narrow side; - second vertical agitator with a second hyperboloid agitator body attached to a second vertical agitator shaft, wherein the second vertical agitator is provided in a second treatment section below the flow of the first vertical agitator; - an aeration device with a fan for aerating the wastewater received in the tank; Petition 870240074974, dated 02 / 09 / 2024, page 7 / 35 3 / 21 - first steering device to rotate the first hyperboloid agitator body in the first direction of rotation; - a second steering device to rotate the second hyperboloid agitator body in a second direction of rotation, which is opposite to the first direction of rotation; and - a settling tank, which is provided to discharge purified wastewater into a third treatment section via a second narrow side, which is opposite the first narrow side.
[007] According to the present invention, wastewater flows from the inlet stream on the first narrow side to the settling tank on the second narrow side. Based on this flow direction, the first vertical agitator is arranged after the inlet stream and the second vertical agitator is arranged after the first vertical agitator. Each of the vertical agitators has a hyperboloid agitator body as its agitator body. As the hyperboloid agitator body rotates, a flow is formed that is directed along the agitator axis in the direction of the hyperboloid agitator body. The flow is deflected at the surface of the hyperboloid agitator body in a substantially horizontal direction. At a certain distance from the peripheral end of the hyperboloid agitator body, the flow is again deflected vertically towards the surface of the wastewater. The flow then runs approximately parallel to the surface and is again deflected in the direction of the agitator axis.Therefore, a circulating flow is formed as a result of the effect of the vertical agitator. The flow additionally rotates axially around the agitator shaft, in the same direction as the agitator shaft's rotation. As... Petition 870240074974, dated 02 / 09 / 2024, page 8 / 35 4 / 21 The first vertical agitator and the second vertical agitator are operated with different directions of rotation, forming a region between the successive vertical agitators in which the flow is directed substantially vertically upwards, towards the surface of the wastewater. There, the flow splits and passes back to the corresponding treatment sections. Due to the use of two vertical agitators rotating in opposite directions, as proposed by the present invention, it is possible to create treatment sections in which wastewater can undergo different treatment stages without the need to provide partition walls in an elongated tank. Wastewater can, for example, be brought into contact with a high concentration of activated sludge in the first treatment section.In the second stage of treatment, the wastewater can be brought into contact with a lower concentration of activated sludge and can also be aerated, preferably simultaneously. Aeration can vary in the treatment stages. The intensity of aeration and the rotation speed of the hyperboloid agitators can also vary in the treatment stages.
[008] The proposed wastewater purification apparatus allows for efficient wastewater purification. It also allows for a continuous or semi-continuous process sequence. Pumps and transfer lines for the treated wastewater from one treatment section to the next are not required. The transfer of treated wastewater from one treatment section to the next can be controlled by an appropriate controller of the rotational speed of the vertical agitators, the amount of wastewater fed through the inlet flow and / or the Petition 870240074974, dated 02 / 09 / 2024, page 9 / 35 5 / 21 amount of wastewater removed by means of the settling tank.
[009] According to a convenient embodiment, first transport ribs provided on an upper side of the hyperboloid agitator body have a first curvature and transport ribs provided on an additional upper side of the second hyperboloid agitator body have a second curvature, which is opposite to the first curvature. Due to the proposed embodiment of the transport ribs, the agitation efficiency and, particularly, the formation of the circulating flow can be improved. The ribs can also be formed in a straight line. In this case, the first transport ribs have a first angle with respect to the radial direction and the second transport ribs have a second angle opposite to the radial direction.
[010] According to a particularly beneficial embodiment, at least one of the hyperboloid agitator bodies is formed as a hollow body and has a central opening for air passage, as well as aeration openings. The agitator shaft can be formed as a hollow shaft for supplying air to the central opening. Furthermore, the drive device can have a transmission with a hollow drive shaft, wherein one of its ends is connected to the fan and the other end is connected to the hollow shaft. According to the proposed embodiment, the hyperboloid agitator body is used for agitation and aeration of wastewater. Several hyperboloid agitator bodies, or all of them, are conveniently formed as hollow bodies for wastewater aeration.
[011] It may naturally occur that the aeration device comprises at least one perforated air supply line, which is supported on a base. Petition 870240074974, dated 02 / 09 / 2024, page 10 / 35 6 / 21 of the tank and is connected to the fan. Devices comprising a series of perforated air supply lines may also be provided. Devices of this type are generally known according to the state of the art.
[012] According to a further embodiment, several first vertical agitators are successively provided in the flow direction in the first part of the treatment and / or several second vertical agitators are successively provided in the flow direction in the second part of the treatment, wherein the hyperboloid agitator bodies of successive agitators are rotated, in each case, with opposite directions of rotation. The proposed embodiment is particularly suitable for long treatment tanks and for the treatment of large quantities of wastewater.
[013] The treatment tank can also be made in such a way that several vertical agitators are arranged perpendicular to the flow direction. If vertical agitators are arranged adjacently perpendicular to the flow direction, they are preferably operated in the same direction of rotation.
[014] According to a convenient embodiment, the hyperboloid agitator body is configured in the form of a hollow body. Conveniently, it has a central opening for air supply and also air outlet openings. The agitator shaft can be formed as a hollow shaft for air supply to the central opening. The drive device can have a transmission with a hollow drive shaft, wherein one of its ends is connected to the fan and the other end is connected to the hollow shaft. Wastewater can be efficiently aerated by means of the agitator body. Petition 870240074974, dated 02 / 09 / 2024, page 11 / 35 7 / 21 proposed hyperboloid. Specifically, it is not necessary to design aeration lines on the base of the tank.
[015] According to a further provision of the present invention, a wastewater purification process is proposed, particularly an RBS process, comprising the following steps: - supplying a wastewater purification apparatus according to the present invention, in which activated sludge is supplied in the first and second stages of treatment; - Wastewater supply via the inlet flow; - Agitation of the suspension formed with wastewater and activated sludge by means of a first vertical agitator in the first part of the treatment, in which the first agitator body rotates at a first previously defined rotation speed in the first direction of rotation and the suspension is aerated by means of the aeration device; - agitation of the suspension by means of the second vertical agitator, in which the second agitator body rotates at a second predefined rotational speed in the second direction of rotation and the suspension is aerated by means of the aeration device; - maintaining the suspension at rest in the third stage of treatment, where it is neither agitated nor aerated by means of the aeration device; and - Decantation of the supernatant using a decanter.
[016] The proposed process allows for particularly efficient wastewater purification. Due to the directions Petition 870240074974, dated 02 / 09 / 2024, page 12 / 35 With the proposed 8 / 21 counter-rotating agitators, it is possible to subject the wastewater to different conditions in the treatment sections thus formed. In the first treatment section, for example, the wastewater can be exposed to a high concentration of activated sludge, while in the second treatment section, the wastewater can be exposed to a high concentration of air. The process can be carried out as a batch process and as a continuous or semi-continuous process.
[017] The first rotation speed is preferably selected to be lower than the second rotation speed. It is therefore possible to bring the wastewater into contact, in the first part of the treatment, with a high concentration of activated sludge. In particular, the unwanted transport of activated sludge from the first part of the treatment to the second part of the treatment can be reduced or eliminated.
[018] If several first vertical agitators are provided in the first treatment section, it is also possible to select that their first rotation speeds are different. The first rotation speed can, for example, be higher in the downstream direction. Similarly, if several second vertical agitators are provided in the second treatment section, it is also possible to select that the second rotation speeds are different. The second rotation speeds can be reduced towards the third treatment section. This assists in the desired separation of the suspension in the third treatment section into activated sludge and treated wastewater.
[019] The first rotational speed is Petition 870240074974, dated 02 / 09 / 2024, page 13 / 35 9 / 21 conveniently selected so that the concentration of activated sludge in the lower half on the base side is higher than in the upper half on the surface side. Wastewater can therefore be brought into contact in the lower half on the base side, with a particularly high concentration of activated sludge.
[020] In the first treatment section, a series of first vertical agitators are provided, arranged successively in the flow direction, and / or, in the second treatment section, a series of second vertical agitators are provided, arranged successively in the flow direction, wherein the hyperboloid agitator bodies of directly successive vertical agitators are rotated, in each case, in opposite directions. In this way, the previously defined retention time of the wastewater in the various treatment sections can be guaranteed.
[021] According to a particularly convenient embodiment, wastewater is fed continuously. Sequential feeding of wastewater is also possible, however. In this case, the process can be carried out according to the RBS process.
[022] In the RBS process, wastewater is agitated in a series of successive stages. It can be aerated simultaneously in one or more stages. It is also possible, however, to aerate wastewater without simultaneously agitating it.
[023] In an additional step, the wastewater is merely agitated at low intensity. In this step, it is not aerated. This step is used for sedimentation.
[024] In a further step, wastewater is Petition 870240074974, dated 02 / 09 / 2024, page 14 / 35 10 / 21 agitated, at most, under low intensity in the first part of treatment. In this stage, the wastewater is decanted in the third part of treatment.
[025] In all the stages mentioned above, wastewater can be continuously fed into the treatment tank via the inlet flow. Sedimentation can also be carried out continuously.
[026] In order to conduct the RBS process, additional steps may be added to the process according to the present invention, in which the wastewater is particularly only agitated, but not aerated.
[027] Conveniently, the suspension is neither agitated nor aerated by means of the aeration device during the stage in which it is held at rest in the second part of the treatment. Furthermore, the suspension may also not be agitated nor aerated by means of the aeration device during the stage in which it is held at rest in the first part of the treatment. The stage of holding the suspension at rest is therefore accelerated. The efficiency of the process can therefore be further increased.
[028] Examples of embodiments of the present invention will be explained in more detail with reference to the figures, in which: - Fig. 1 shows a schematic plan view of an early wastewater purification device; - Fig. 2 shows a schematic cross-sectional view according to Fig. 1; - Fig. 3 shows a schematic plan view of a second wastewater purification device; Petition 870240074974, dated 02 / 09 / 2024, page 15 / 35 11 / 21 - Fig. 4 shows a cross-sectional view according to Fig. 3; - Fig. 5 shows a schematic plan view of a first hyperboloid agitator body; - Fig. 6 shows a schematic plan view of a second hyperboloid agitator body; - Fig. 7 shows a partially broken perspective view of a third hyperboloid agitator body; - Fig. 8 shows a plan view of an upper roof; - Fig. 9 shows a bottom view according to Fig. 8; - Fig. 10 shows a plan view of a lower roof; - Fig. 11 shows a bottom view according to Fig. 10; and - Fig. 12 shows a schematic cross-sectional view through an engine and transmission.
[029] Figs. 1 and 2 show views of a first wastewater purification apparatus. The first wastewater purification apparatus comprises an elongated tank 1, which has an inlet flow 2 on its first narrow side S1 for feeding wastewater. On the second narrow side S2, which is opposite the first narrow side S1, a settling tank 3 is provided for discharging purified wastewater. The first long side of tank 1 is indicated by L1; and the opposite second long side is indicated by L2. After the inlet flow, a first vertical agitator 4 is provided, which has a first hyperboloid agitator body 6 on a first Petition 870240074974, dated 02 / 09 / 2024, page 16 / 35 12 / 21 agitator shaft 5. Reference mark 7 indicates a second vertical agitator, which has a second hyperboloid agitator body 9 on a second agitator shaft 8.
[030] The first vertical stirrer 4 has a first steering device (not shown herein), by means of which the first hyperboloid stirring body 6 is rotated counterclockwise in plan view. The second vertical stirrer 7 is equipped with a second steering device (not shown herein), by means of which the second hyperboloid stirring body 9 is rotated clockwise.
[031] In the case of the second wastewater purification apparatus schematically shown in Figs. 3 and 4, two first vertical agitators 4a, 4b are successively provided in the flow direction from the inlet flow 2 to the settling tank 3, followed by two second vertical agitators 7a, 7b. The first steering devices (not shown herein) of the first vertical agitators 4a, 4b are designed so that the hyperboloid agitator bodies 6a, 6b of the vertical agitators are rotated in opposite directions. Similarly, the second steering devices (not shown herein) are designed so that the second hyperboloid agitator bodies 9a, 9b are also rotated in opposite directions. The first hyperboloid agitator body 6b of the first vertical agitator 5b conveniently rotates in the opposite direction to the second hyperboloid agitator body 9a of the second vertical agitator 7a.Consequently, in this convenient embodiment, successive hyperboloid agitating bodies 6a, 6b, 9a, 9b rotate separately in opposite directions. Petition 870240074974, dated 02 / 09 / 2024, page 17 / 35 13 / 21
[032] At least one first vertical agitator 4, 4a, 4b is arranged in the first treatment section A of tank 1 provided after the inlet flow 2. At least one second vertical agitator 7, 7a, 7b is arranged in the second treatment section B provided below the flow of the first treatment section A. There is no vertical agitator arranged in the present third treatment section C after the second treatment section B. The settling tank 3 is located in the aforementioned third treatment section. It may also occur, however, that at least one vertical agitator is similarly provided in the third treatment section C.
[033] Aeration devices (not shown herein) are provided in the first treatment section A and in the second treatment section B. These devices may be perforated feed lines deposited on the base F of tank 1. According to a specific preferred embodiment, air is fed through hyperboloid agitator bodies 6, 6a, 6b, 9, 9b, 9a, which are preferably formed as hollow bodies.
[034] The proposed wastewater purification devices operate as follows:
[035] The rotation of one of the hyperboloid agitator bodies 6, 6a, 6b, 9, 9a, 9b results in a directed flow from a surface O of wastewater W received in tank 1 along the vertical agitator axis 5, 8 to an upper side of the hyperboloid agitator body 6, 6a, 6b, 9, 9a, 9b. The flow is then diverted, parallel to the upper side of the hyperboloid agitator body 6, 6a, 6b, 9, 9a, 9b in a substantially horizontal direction. It is further diverted and again directed to the upper side O. Finally, Petition 870240074974, dated 02 / 09 / 2024, page 18 / 35 14 / 21 a directed circulating flow is created from the upper side O to a base F of tank 1.
[036] As can be seen specifically in Figures 2 and 4 show flow sections formed during the operation of adjacent vertical agitators 4, 4a, 4b, 7, 7a, 7b, where the flow sections are delimited by previous flows resulting between two successive vertical agitators 4, 4a, 4b, 7, 7a, 7b from the base F towards the surface O and the two longitudinal sides L1 and L2 of tank 1. Only a small exchange of suspension formed from the wastewater W and activated sludge occurs between successive flow sections. The exchange or transport of the suspension from the inlet stream 2 to the settling tank 3 can be controlled by one or more of the following parameters: - quantity of wastewater W fed through inlet flow 2 per unit of time; - rotation speed of the first and / or second vertical agitators 4, 4a, 4b, 7, 7a, 7b; and - quantity of purified wastewater W removed per unit of time, through the decanter 3.
[037] Fig. 5 shows, for example, a plan view of an upper side O1 of the first hyperboloid agitator. First transport ribs 10 extend over the first upper side O1 and run from the first agitator axis 5, initially in the radial direction, to the peripheral end U of the first hyperboloid agitator body 6. The first transport ribs 10, following the first curvature, are then deflected in a tangential direction towards the peripheral end U.
[038] Fig. 6 shows a plan view from one side Petition 870240074974, dated 02 / 09 / 2024, p. 19 / 35 15 / 21 additional upper part of the second hyperboloid agitator body 7. In it, second transport ribs 11 extend from the second agitator shaft 8, again in the radial direction, and are deflected towards the peripheral end U according to the second curvature in the tangential direction. The first curvature is opposite to the second curvature. Due to the different embodiment of the first transport ribs 10 and the second transport ribs 11, the first hyperboloid agitator body 5 is particularly suitable for counterclockwise rotation, while the second hyperboloid agitator body 7 is suitable for clockwise rotation. A particularly efficient circulating flow from the base F to the surface O can be generated with the use of hyperboloid agitator bodies 6, 7.
[039] Figs. 7 to 11 show a convenient embodiment of hyperboloid shaking bodies.
[040] In Fig. 7, a hyperboloid agitator body is mounted on a hollow agitator shaft 12. The hyperboloid agitator body has a central connection part indicated by the reference mark 13. The connection part 13 has a central opening 14 for air passage.
[041] Reference mark 16 indicates an upper cover, wherein the transport ribs 17 extend from its first upper side O1. Reference mark 18 indicates a lower cover, wherein the walls 19 extend from its second upper side O2. Reference mark 20 indicates an insert that is provided below the flow opening 14 and an air distribution space 15. The insert 20 is formed as a conical beaker and has a series of air distribution openings 21 on its Petition 870240074974, dated 02 / 09 / 2024, page 20 / 35 16 / 21 perimeter wall. Each of the air distribution openings 21 leads to an air channel 22 formed by adjacent walls 19, the upper cover 16 and the lower cover 18. Shear ribs 23 are mounted on a second lower side U2 of the lower cover 18 and its perimeter end.
[042] Fig. 8 shows a plan view of the first upper side O1 of the top cover. The conveying ribs 17 extending from the first upper side O1 are visible and run from the opening 14, first radially and then towards the peripheral end U in a tangential direction. Also conceivable is the insert 20 arranged below in the flow of opening 14 and having the air distribution openings 21.
[043] Fig. 9 shows a bottom view according to Fig. 8. The transport ribs 17 in the form of notches are visible on the first lower side U1 of the upper cover 16.
[044] Fig. 10 shows a plan view of the second upper side O2 of the lower cover 18. The lower cover 18 is closed at its center, i.e., opposite the opening 14 provided in the upper cover 16. The walls 19 extend from the second upper side O2. The walls 19 – similarly to the transport ribs 17 – emerge from the center, first in a radial direction, and are then diverted in a substantially tangential direction towards the peripheral end U. Several retaining devices 24 are situated at the peripheral end U and form notches in the second upper side O2. The retaining devices 24 are used, as can be seen specifically in conjunction with Fig. 11 explained above, to receive and secure the ribs. Petition 870240074974, dated 02 / 09 / 2024, p. 21 / 35 17 / 21 shear 23.
[045] Fig. 11 shows a bottom view according to Fig. 10. The walls 19 are visible in the form of notches on a second lower side U2 of the lower cover. The retaining devices 24, on the other hand, extend from the second lower side U2. Reference is also made, in this particular, to Fig. 7. An air outlet opening 25 is provided between each two adjacent retaining devices 24 or two adjacent shear ribs 23.
[046] Fig. 12 shows a schematic cutaway view through a transmission 27 which is connected in terms of drive to a motor 26. The transmission 27 has a hollow drive shaft 28, the first end of which is connected to an air supply line 29. A fan connected to the air supply line 29 is not shown here. The second end E2 of the hollow drive shaft is connected to the hollow agitator shaft 12. As can be seen in Fig. 7, the third end E3 of the hollow agitator shaft 12 is connected to the hyperboloid agitator body shown in Figs. 7 to 11.
[047] The agitation and gasification device resulting particularly from Figs. 7 to 12 can be mounted, for example, on a beam or bridge 30 (see Fig. 12), which covers the tank 1 between its two long sides L1 and L2.
[048] A wastewater purification process, particularly an RBS process, can be carried out particularly efficiently with the proposed wastewater purification apparatus.
[049] In order to carry out the process, a previously defined quantity of activated sludge is added to water. Petition 870240074974, dated 02 / 09 / 2024, p. 22 / 35 18 / 21 wastewater W located in tank 1 in the first treatment section A. At least one first vertical agitator 4, 4a, 4b rotates at a previously defined first rotation speed, so that a suspension of wastewater W and activated sludge is formed. At the same time, at least one second vertical agitator 7, 7a, 7b rotates at a second rotation speed. The second rotation speed is conveniently higher than the first rotation speed. Consequently, and particularly due to the opposite directions of rotation of the successive vertical agitators, a suspension with a high concentration of activated sludge is formed in the first treatment section A and a suspension with a lower concentration of activated sludge is formed in the second treatment section B.
[050] During the operation of the vertical agitators, the suspension circulates according to the flow direction shown in Figs. 2 and 4. In doing so, the suspension is aerated, conveniently simultaneously. Consequently, the microorganisms contained in the activated sludge are fed. The microorganisms decompose organic impurities in the wastewater.
[051] In the third treatment section C, the suspension is left to rest. The suspension may, however, also be slowly agitated by means of at least one third vertical agitator (not shown herein) in the third treatment section C. There, it normally has an even lower concentration of activated sludge than in the second treatment section B. In the third treatment section C, a supernatant forms in the treated wastewater, which is removed by means of the settling tank 3. During the settling process, the at least Petition 870240074974, dated 02 / 09 / 2024, page 23 / 35 19 / 21 a third vertical stirrer is conveniently switched off.
[052] The proposed method can be conveniently carried out by means of a constant feed of wastewater through the inlet flow 2 and discharge of a corresponding quantity of treated wastewater through the settling tank 3.
[053] The proposed method, however, can also be conducted conventionally in the form of an RBS process. For this purpose, the first vertical agitators 4, 4a, 4b and the second vertical agitators 7, 7a, 7b are operated only temporarily. During the shutdown times of vertical agitators 4, 4a, 4b, 7, 7a, 7b, a supernatant forms in the treated wastewater in treatment section C, which can then be removed by means of the settling tank 3. List of reference signs: inlet flow tank, decanter, 4a, 4b first vertical agitator, 5a, 5b first agitator shaft, 6a, 6b first hyperboloid agitator body, 7a, 7b second vertical agitator, 8a, 8b second agitator shaft, 9a, 9b second hyperboloid agitator body, first transport ribs, second transport ribs, agitator shaft, connecting part opening. Petition 870240074974, dated 02 / 09 / 2024, page 24 / 35 20 / 21 15 air distribution space 16 top cover 17 transport rib 18 bottom cover 19 wall 20 insert 21 air distribution opening 22 air channel 23 shear rib 24 retaining device 25 air outlet opening 26 motor 27 transmission 28 hollow transmission shaft 29 air supply line 30 float A first treatment part B second treatment part C third treatment part E1 first end E2 second end E3 third end F base L1 first long side L2 second long side O surface O1 first top side O2 second top side S1 first narrow side S2 second narrow side Petition 870240074974, dated 02 / 09 / 2024, page 25 / 35 21 / 21 U U1 U2 W peripheral end first lower side second lower side wastewater Petition 870240074974, dated 02 / 09 / 2024, page 26 / 35
Claims
1 / 4 CLAIMS 1. WASTEWATER PURIFICATION PROCESS, particularly an RBS process, characterized by comprising the following steps: - supply of a wastewater purification apparatus, the wastewater purification apparatus comprising an elongated tank (1) which, on its first narrow side (S1), has an inlet flow (2) for wastewater feed (W), a first vertical agitator (4, 4a, 4b) with a first hyperboloid agitator body (6, 6a, 6b) mounted on a first vertical agitator shaft (5, 5a, 5b), wherein the first vertical agitator (4, 4a, 4b) is provided in the first treatment section (A) below the inlet flow (2) of the first narrow side (S1), a second vertical agitator (7, 7a, 7b) with a second hyperboloid agitator body (9, 9a, 9b) mounted on a second agitator shaft vertical (8, 8a, 8b), wherein the second vertical agitator (7, 7a,7b) is provided in the second treatment section (B) below in the flow of the first vertical agitator (4, 4a, 4b), an aeration device with a fan for aerating the wastewater (W) received in the tank (1), a first steering device to rotate the first hyperboloid agitator body (6, 6a, 6b) in the first direction of rotation, a second steering device to rotate the second hyperboloid agitator body (9, 9a, 9b) Petition 870240074974, dated 02 / 09 / 2024, page 27 / 35 2 / 4 in the second direction of rotation, which is opposite to the first direction of rotation, and a settling tank (3), which is provided to discharge purified wastewater (W) into a third treatment section (C) on a second narrow side (S2), which is opposite to the first narrow side (S1),wherein activated sludge is supplied in the first treatment section (A) and in the second treatment section (B); - wastewater feed (W) through the inlet flow (2); - agitation of the suspension formed with the wastewater (W) and the activated sludge by means of the first vertical agitator (4, 4a, 4b) in the first treatment section (A), wherein the first hyperboloid agitator body (6, 6a, 6b) rotates at a previously defined first rotation speed in the first direction of rotation and the suspension is aerated by means of the aeration device; - agitation of the suspension by means of the second vertical agitator (7, 7a, 7b), wherein the second hyperboloid agitator body (9, 9a, 9b) rotates at a previously defined second rotation speed in the second direction of rotation and the suspension is aerated by means of the aeration device; - maintenance of the suspension at rest in the third treatment section (C),wherein the suspension is neither agitated nor aerated by means of the aeration device; and - decantation of the supernatant by means of the decanter (3)., 2. PROCESS according to claim 1, characterized in that the first rotation speed is selected so that it is lower than the second rotation speed.
3. PROCESS, according to any one of claims 1 or 2, characterized in that the first rotation speed is selected such that the concentration of activated sludge in the lower half on the base side of the suspension is greater than in the upper half on the surface side.
4. PROCESS, according to any one of claims 1 to 3, characterized by several first vertical agitators (4, 4a, 4b) being successively provided in the flow direction in the first treatment part (A) and / or several second vertical agitators (7, 7a, 7b) being successively provided in the flow direction in the second treatment part (B), wherein the hyperboloid agitator bodies (6, 6a, 6b, 9, 9a, 9b) of directly successive vertical agitators (4, 4a, 4b, 7, 7a, 7b) rotate independently with opposite directions of rotation.
5. PROCESS, according to any one of claims 1 to 4, characterized in that wastewater is continuously fed.
6. PROCESS, according to any one of claims 1 to 4, characterized in that wastewater is fed sequentially.
7. PROCESS, according to any one of claims 1 to 6, characterized in that the suspension is neither agitated nor aerated by means of the aeration device during the step in which the suspension is kept at rest in the second part of treatment (B) and / or in the third part of treatment (C). Petition 870240074974, dated 02 / 09 / 2024, p. 29 / 35 4 / 4 8. PROCESS, according to any one of claims 1 to 7, characterized in that the suspension is neither agitated nor aerated by means of the aeration device during the step in which the suspension is kept at rest in the first part of treatment (A). Petition 870240074974, dated 02 / 09 / 2024, pp. 30 / 35