WO2011023408A1

WO2011023408A1 - Waste water purification plant and method for purifying waste water

Info

Publication number: WO2011023408A1
Application number: PCT/EP2010/005310
Authority: WO
Inventors: Peter Hartwig
Original assignee: Peter Hartwig
Priority date: 2009-08-31
Filing date: 2010-08-30
Publication date: 2011-03-03
Also published as: DE102009039316A1; BR112012004572A2

Abstract

The invention relates to a waste water purification plant having a) an intake mixing tank (3), b) a combined reaction and sedimentation tank (1, 2) having a first and a second tank section, c) wherein d) a first connection point (11) is arranged between the intake mixing tank (3) and the first tank section (1) in the lower tank region of the first tank section (1), c2) a first pump (12) is arranged at the first connection point (11) and can be actuated to convey return sludge from the first tank section (1) into the intake mixing tank (3), c3) a first clarified water drain point (13) is arranged in the upper tank region of the first tank section (1), and d) wherein d1) a second connection point (21) is arranged between the intake mixing tank (3) and the second tank section (2) in the lower tank region of the second tank section (2), d2) a second pump (22) is arranged at the second connection point (21) and can be actuated to convey return sludge from the second tank section into the intake mixing tank (3), and d3) a second clarified water drain point (23) is arranged in the upper tank region of the second tank section (2). The invention also relates to a method for purifying waste water, in particular for the biological purification of waste water according to the activated sludge process, and to a method for after-treating the activated sludge.

Description

WASTEWATER CLEANING SYSTEM AND METHOD FOR WASTEWATER CLEANING

The invention relates to a wastewater treatment plant according to claim 1. The invention also relates to a process for wastewater treatment according to claim 11. The invention relates in particular to the biological wastewater treatment according to the sludge process.

In the field of biological wastewater treatment according to the sludge slurry process, there are two principal ways of building a wastewater treatment plant to be used therefor. In a first type of construction, a reaction basin and a spatially separated sedimentation basin are provided. The reaction tank has the function of a biological reactor, i. The wastewater is treated by the bacteria contained in the activated sludge. After a certain treatment time, the wastewater-activated sludge mixture is transferred from the reaction tank into the sedimentation tank. Sedimentation takes place in the sedimentation basin by setting only a very low flow velocity. In the process, the activated sludge deposits at the bottom of the sedimentation basin, while a clear water layer forms in the upper basin area, from which the clear water is drawn off. The activated sludge is returned to the reaction tank and excess sludge is withdrawn. The operation of such a system is continuous.

A second principle of a sewage treatment plant is a so-called sequencing batch reactor, also referred to as SBR reactor. Here are the

BESTATIGUNGSKOPIE Reaction basin and the sedimentation basin combined into a combined reaction and sedimentation basin. The loading of the SBR reactor with wastewater takes place cyclically. The spatial separation between the reaction treatment of the wastewater and the sedimentation described above is replaced by a temporal separation in the SBR reactor. A reaction treatment is first carried out in the basin, followed by a sedimentation phase and a clear water and excess sludge discharge phase. An SBR reactor is known, for example, from DE 20 2004 010 466 U1.

The advantage of the continuous process lies in the simple mode of operation and the smaller volume required; However, the continuous process requires a higher outlay for the mechanical installation than the SBR process. The SBR process is more flexible in adapting to different loading and operating situations than the continuous process, through the possible adjustment of cycle times, but generally requires additional volume for the storage of the waste water during non-feed operating periods and to cover the loading - Operating times with clear water and sludge removal, in which the SBR reactor can not be used for biological purification or sedimentation. In addition, when introduced into sensitive waters equalization of cyclically drained drains may be required, which in turn requires an additional storage volume.

The present invention is based on the object of demonstrating possibilities for wastewater treatment, with which wastewater in a space-saving design particularly efficient, with only a few mechanical installations can be cleaned energy-saving in a very economical manner.

This object is achieved by a wastewater treatment plant according to claim 1 and a method for wastewater treatment according to claim 11. The subclaims contain advantageous embodiments of the invention.

The present invention advantageously shows a possibility of constructing a wastewater treatment plant which is relatively small in size and therefore relatively inexpensive to produce, with comparatively little effort for the mechanical engineering installations. The invention makes it possible to operate the wastewater treatment plant in a kind of semi-continuous cyclic process, in comparison to the continuous process, as described in the opening paragraph, which requires separate tanks for the reaction and the sedimentation. The present invention therefore combines the advantages of purely continuous wastewater treatment, namely the advantage of consistently effective volume used and the possible waiver of pre- and / or Nachspeicher, with the advantage of flexibility by the choice of cycle times for the flow direction change and the possible machine technology simple equipment of SBR reactors.

For this purpose, the wastewater treatment plant according to the invention has a combined reaction and sedimentation basin with a first and a second basin section. Compared to the reaction and sedimentation tank of a conventional SBR reactor is provided according to the invention as a special feature that a first connection point between an inlet mixing basin and the first basin section and a second connection point between the inlet mixing basin and the second basin section is provided hen. The connection points are located in the lower pelvic region of the respective pelvic section, eg near the bottom of the respective pelvic section. At each junction, a conveyor is provided in each case, which can be actuated to promote return sludge from the respective basin section in the inlet mixer. As return sludge a proportion of the sludge is called, which is recycled from a basin of the wastewater treatment plant in the inlet mixing basin. In addition, one ne first clear water outlet in the upper pelvic area of the first pelvic section and a second clear water outlet in the upper pelvic area of the second pelvic section arranged. As conveyor any type of device can be used, which is suitable for the promotion of sewage and sludge, such as a commercial pump. Suitable is eg a propeller pump.

Such an arrangement allows phased operation of the wastewater treatment plant in different flow directions. Thus, in a first operating phase of the wastewater treatment plant, the first basin section can be used as reaction section and the second basin section as sedimentation section. In a second phase of operation, however, the first basin section is used as sedimentation section and the second basin section as reaction section. By circulation or aeration, the sedimented sludge is re-mixed with the tank contents after the sedimentation phase at the beginning of a new reaction phase. This provides the total volume of biological activity. Since a conveyor is provided for the return of return sludge at each of the two connection points, depending on the operating direction of the wastewater treatment plant in one case, the first conveyor the return sludge from the operated as Sedimentationsabschnitt pool section back into the inlet mixing basin and in the other phase of operation, the second conveyor. In addition, a respective assigned clear water outlet in the upper basin area is provided both in the first basin section and in the second basin section. This allows a clear water withdrawal in each case from the pool section, which is just the sedimentation depending on the operating phase of the wastewater treatment plant.

By the arrangement of the respective connection point, which is responsible for the return sludge is used, in the lower basin area, ie near the bottom, and the respective clear water outlet in the upper basin area of the same basin section results in a rectified flow of clear water and return sludge, which reduces turbulence and causes a particularly good sedimentation performance.

According to an advantageous development of the invention, a first charging point for supplying wastewater to be cleaned is arranged from the inlet mixing basin into the combined reaction and sedimentation basin between the inlet mixing basin and the first basin section in the lower basin area of the first basin section. A second feed point for supplying waste water to be cleaned from the inlet mixing basin into the combined reaction and sedimentation basin is arranged between the inlet mixing basin and the second basin section in the lower basin area of the second basin section. Waste water can be supplied from the inlet mixing basin into that basin section of the combined reaction and sedimentation basin via the respective feed point, which is currently being operated as a reaction section. As far as in the present patent application of the supply of wastewater from the run-mix pool in the combined reaction and sedimentation is mentioned, this also includes the supply of activated sludge, especially in the run-mix pool a mixture of wastewater and activated sludge is generated.

According to an advantageous embodiment of the invention, the first connection point is at the same time the first loading point and / or the second connection point at the same time the second loading point. The respective connection point can advantageously have a double function, so that no separate connection between the inlet mixing basin and the combined reaction and sedimentation basin for the supply of wastewater is provided. that must. Depending on the operating phase of the associated basin section of the reaction and sedimentation basin, the respective connection point advantageously functions as a charging point or as a return sludge discharge. This allows a simpler and more cost-effective realization of the wastewater treatment plant. In addition, provided for the promotion of return sludge each conveyor can be used at the same time to support the feeding of the reaction and sedimentation basin with waste water, without an additional conveyor would be required if necessary.

The first and the second connection point or the first or the second loading point can in a simple embodiment as an opening, e.g. as a hole, be formed in a partition between the inlet mixing basin and the respective basin section of the reaction and sedimentation basin.

The change of a pool section between reaction and sedimentation operation may also be time overlapping, e.g. Waste water from the inlet mixing basin is already supplied to the bottom, while at the clear water outlet point of the same basin section clear water is removed for a certain time.

The invention has the particular advantage that the liquid level in the combined reaction and sedimentation tanks can be kept almost constant, ie, the cyclic level changes typical of SBR reactors do not occur. As a result, clear water can be withdrawn almost continuously in the same quality at the surface of the sedimentation of the combined reaction and sedimentation tank. In addition, eliminating the need for powerful pumps or decanters for cyclically pumping out the clear water with respect to the inlet greatly increased capacity. The inlet mixing basin and the reaction basin can be ventilated or unventilated, aerobic, anoxic or anaerobic. Anaerobic operation means operation in the absence of oxygen. However, if at least undissolved bound oxygen is present, it is an anoxic mode of operation. If there is dissolved oxygen, it is an aerobic mode of operation. According to an advantageous development of the invention, at least one ventilation device and / or a mixing device are provided in the inlet mixing basin, the combined reaction and sedimentation basin and / or a sludge aftertreatment basin, eg with biological activity. The aerator serves to supply air to the basin contents to effect favorable reaction conditions. The ventilation device has, for example, one or more ventilation tubes, which are guided in the region of the bottom of a basin and have air outlet openings in this area or are additionally equipped with air distribution devices such as, for example, fine-pore ventilation elements.

The mixing device is used for mixing a pool content, the mixing is usually carried out in a reaction phase and is used to circulate the pool contents. The mixing device can be designed, for example, as a circulating device installed in the lower pelvic region, which performs rotational movements in the manner of a propeller.

According to an advantageous development of the invention, an additional installation is provided in the region of the clear water removal point for minimizing flocculation, which additionally reduces the content of filterable substances, for example in the case of particularly stringent requirements for the effluent quantity. formality. This may advantageously be lamella separators, for example, in the reaction and sedimentation tanks or a downstream filtration stage.

The invention can be advantageously used for the purification of municipal, industrial or mixed wastewater for a particularly efficient and economical wastewater treatment. Advantageously, the individual basins of the wastewater treatment plant according to the invention can in principle have any shapes, such as rectangular or round, and be constructed from any suitable materials.

The conveying devices mentioned at the junctions between the reaction and sedimentation basins and the inlet mixing basin can each be actuated in a first pumping direction to convey return sludge from the reaction and sedimentation basins into the inlet mixing basin. In addition, each of the conveyors can be actuated in the opposite pumping direction to convey wastewater from the inlet mixing basin into the reaction and sedimentation basin.

According to an advantageous development of the invention, a control device is provided for controlling the actuation of the first and the second conveyor device. The control device may be designed in the form of a separate control for the first conveyor and a separate controller for the second conveyor or as an integrated control device for both conveyors. The control device is designed to actuate either the first or the second conveying device for conveying return sludge from the reaction and sedimentation basin into the inlet mixing basin. In this way, a defined return of the return sludge is ensured in the inlet mixing basin of the present in the sedimentation phase pool part. In an operating mode, the control device can advantageously also overlap in time, for a short period of time compared to the duration of the sedimentation phase, both Operate conveyors for pumping return sludge from the reaction and sedimentation basins into the inlet mixing basin. The period of the time-overlapping actuation may, for example, be up to two hours. According to an advantageous development of the invention, the reaction and sedimentation basin has a reaction section for the reaction treatment of the basin contents and a sedimentation section for the simultaneous sedimentation of the basin contents. Advantageously, at least in certain time periods, a simultaneous reaction treatment and sedimentation in the combined reaction and sedimentation tanks take place.

According to an advantageous development of the invention, the reaction and sedimentation basin has at least one further reaction section for the reaction treatment of the basin contents. It is conceivable to provide one or more further reaction sections, and thereby spatially and functionally further decoupling the first basin section from the second basin section and to provide different functionalities of wastewater purification (eg denitrification / nitrification). According to an advantageous development of the invention, the first basin section is connected to the second basin section via a flow-reducing device. The flow reduction device can also be provided between the first reaction section and one or more further reaction sections of the reaction and sedimentation basin. It may also be provided more than a flow reduction device. By means of the flow reduction device, mixing of the contents of the individual basin sections, for example as a result of turbulences, is advantageously reduced, so that the sedimentation can proceed more undisturbed and thus more quickly. By way of example, a submerged transverse crosspiece arranged in the region of the upper edge of the basin can be provided as a flow reduction device. Also possible is an intermediate wall provided with openings the pelvis.

According to an advantageous development of the invention, the first connection point is connected to a first distribution device arranged in the reaction and sedimentation basin. Alternatively or additionally, the second connection point may be connected to a second distribution device arranged in the reaction and sedimentation basin. Through the distribution device, a more uniform, better distributed introduction of wastewater to be cleaned at the bottom of the reaction and sedimentation tank done. In addition, the distribution device can be used in the reverse operating direction for the suction of return sludge, thereby causing a more uniform absorption of the return sludge.

According to an advantageous development of the invention, the first distributor device and / or the second distributor device is designed as a distributor tube. The manifold may have a plurality of openings over its longitudinal extent. As a result, a uniform distribution of incoming wastewater and a uniform absorption of aspirated return sludge can be achieved. The distributor tube can advantageously extend over the width of the reaction and sedimentation basin.

According to an advantageous development of the invention, the inlet mixing basin is at least partially disposed in a region surrounding the reaction and sedimentation basin. As a result, the wastewater treatment plant according to the invention is particularly compact and space-saving to build. In addition, the connections between the inlet mixing basin and the reaction and sedimentation basin at the first and the second connection point are relatively short. As a result, the expense of erecting the wastewater treatment plant according to the invention is further reduced, which leads to lower production costs. In addition, the joints are aerodynamically executable, ie, it can be achieved a lower flow resistance than with longer connection lines.

According to an advantageous embodiment of the invention, the reaction and sedimentation tank is connected via a further connection point with a

Connected to sludge aftertreatment tanks. Mud aeration may be carried out by means of the mud aftertreatment basin, e.g. for achieving a sludge stabilization. The sludge aftertreatment basin is charged with excess sludge. The feeding of the sludge aftertreatment basin takes place after a sedimentation phase in the sludge aftertreatment basin. The feed takes place from the reaction and sedimentation tanks, from the inlet mixing basin or, advantageously, from a connecting point formed as a shaft between the reaction and sedimentation basins and the inlet mixing basin. The feed advantageously takes place from a basin section located in the sedimentation phase or, based on the connection point, from the phase of return sludge conveying. In the upper area, so-called sludge water forms in the sludge aftertreatment basin, i.

Water with a relatively low sludge content. When loading the

Sludge aftertreatment basin with excess sludge becomes that

Muddy water displaced into an adjacent basin. In this way, the sludge thickens in the sludge aftertreatment tank.

According to an advantageous development of the invention, the sludge aftertreatment basin is at least partially disposed in an area surrounding the reaction and sedimentation basin. As a result, the wastewater treatment plant according to the invention can be built compact and space-saving. In addition, short communication paths between the sludge aftertreatment basin and the other basins can be realized. According to an advantageous development of the invention, the inlet mixing basin is preceded by a storage tank. The reservoir is used advantageously as a buffer to compensate for peak loads from a feed to the wastewater.

According to an advantageous embodiment of the invention, the first and / or the second connection point is at least partially vertically extending shaft-like design. Such a shaft-like vertical formation of at least part of the connection point offers advantageous installation options for the respective conveyor. In addition, due to the vertical course, a difference in height between the inlet mixing basin and the associated section of the reaction and sedimentation basin can be provided such that an inflow of wastewater from the inlet mixing basin into the reaction and sedimentation basin can take place without actuation of the conveyor due to height differences. As a result, the conveyor can be spared. In addition, the energy consumption can be reduced. Turning on the conveyor is then only required for the return of return sludge in the inlet mixer.

Of course, the conveyor may nevertheless be operated in addition to the conveyance of waste water from the inlet mixing basin into the reaction and sedimentation basin, e.g. to speed up the wastewater supply.

According to an advantageous embodiment of the invention, the first and the second conveyor is arranged in a vertical wall of a shaft-like region of the first and the second connection point. This advantageously allows easy placement of a commercial pump. Advantageously, the respective conveying device is arranged in a vertical wall of the shaft-like region facing the inlet mixing basin.

The shaft-like region can be advantageously designed as a connection shaft. The shaft-like region or the connection shaft can be arranged in the inlet mixing basin or the reaction and sedimentation basin be. Also advantageous is a partial arrangement of the shaft-like area or of the connection shaft in the inlet mixing basin and the reaction and sedimentation basin. Advantageously, the shaft-like region or the connection shaft has the function of establishing a connection between the inlet mixing basin and the reaction and sedimentation basin.

According to an advantageous development of the invention, a sludge aftertreatment basin with biological activity is provided which has special properties. Thus, a sludge feed point arranged in the lower basin region of the sludge aftertreatment basin and a sludge water drainage point or a sludge water overflow located in an uppermost basin area of the sludge aftertreatment basin are provided. The sludge aftertreatment basin can be provided with a ventilation and / or mixing device. The sludge aftertreatment basin can be ventilated, anoxic or anaerobic, which has the advantage over conventional plants that the

Sludge thickening can take place in the same basin in combination with a biological reaction. In known systems, however, only the function of thickening is provided.

In the anaerobic mode of operation, the sludge aftertreatment basin can advantageously be covered gas-tight and equipped with a suitable outlet for the sewage gas.

In non-anaerobic operation, a simple muddy water overflow may be provided for the discharge of the supernatant muddy water, e.g. at the upper edge of the pool, since sludge aftertreatment tanks do not have to be closed in a gastight manner in this mode of operation.

The sludge aftertreatment basin has a sludge take-off facility. The pelvis is charged after a settling time without recirculation or aeration, so that the supernatant sludge water runs off and thus a concentration of the post-treated sludge is achieved. Advantageously, the supernatant sludge water runs off due to the displacement effect as a result of the new charging of the basin, without the need for additional mechanical or movable components for this purpose. For example, no turbid water drainage device is needed as in known systems. The displacement effect causes a drainage of the sludge water in the upper pelvic area, while the underlying mud thickens.

According to an advantageous development of the invention, the sludge water discharge point is connected to the reaction and sedimentation basin and / or the inlet mixing basin. Unless the sludge aftertreatment basin is operated anaerobically, the sludge drainage point may be relatively simple, e.g. in the form of an overflow at the upper edge of the pool. When the sludge aftertreatment basin is charged with excess sludge, the sludge water is displaced into an adjacent basin.

According to an advantageous development of the invention, the sludge discharge point is arranged on the side of the sludge aftertreatment basin opposite the sludge feed point. This allows a rectified operation of the sludge aftertreatment basin, i.e., swirling of the pool contents can be largely avoided, since the flow directions at the muddy water drainage point and the

Mud supply point are rectified.

According to an advantageous embodiment of the invention, the installation of a pre-settling tank is provided in front of the inlet mixing basin, advantageously with a supply of the primary sludge in the sludge aftertreatment basin. As a result, considerable energy can be saved, especially in anaerobic operation. In a method for wastewater treatment according to the invention, it is provided that the wastewater to be purified is first fed to an inlet mixing basin and then to a combined reaction and sedimentation basin, wherein in an operating phase of the wastewater treatment plant to be cleaned wastewater the reaction and sedimentation over a first in the lower basin area, eg near the bottom, the reaction and sedimentation basin arranged feeding or connection point is fed and at a second in the lower pool area, for example near the bottom, the reaction and sedimentation basin arranged junction return sludge from the reaction and sedimentation basin is fed into the inlet mixing basin. The method can be used in particular for operating a wastewater treatment plant of the type described above. As a result, an efficient and cost-effective wastewater treatment is possible.

According to an advantageous embodiment of the invention, the reaction and sedimentation basin is operated in the reverse flow direction in another phase of operation of the wastewater treatment plant. In this case, wastewater to be purified is fed to the reaction and sedimentation tank via the second connection parts or a second feed point, and at the first connection point, return sludge is passed from the reaction and sedimentation basin into the inlet mixing basin.

According to an advantageous embodiment of the invention, the first connection point is at the same time the first loading point and / or the second connection point at the same time the second loading point, which allows the already explained above advantageous double function of the respective connection point.

According to an advantageous development of the invention, provision is made for one section of the reaction and sedimentation basin to be used as a reaction section for the reaction treatment of the basin contents and another for a reaction section. section of the reaction and sedimentation is operated as Sedimentationsabschnitt for at least temporarily simultaneous reaction treatment of the basin content, the Reaktionsabschπrtt and Sedimentationsabschnitt change depending on the operating phase of the wastewater treatment plant.

According to an advantageous development of the invention, it is provided that clear water is removed from the reaction and sedimentation tank via a clarifier discharge point, which is arranged in the sedimentation section.

According to an advantageous embodiment of the invention, it is provided that a timely overlapping removal of clear water from the reaction and sedimentation tank and return of return sludge from the reaction and sedimentation tank in the inlet mixing basin takes place.

According to an advantageous embodiment of the invention, it is provided that a temporally overlapping supply of wastewater to be cleaned into the reaction and sedimentation tank and return of return sludge from the reaction and sedimentation basin is carried out in the inlet mixing basin.

According to an advantageous embodiment of the invention, it is provided that a removal of clear water from the reaction and sedimentation tank and a return of return sludge from the reaction and sedimentation tank in the inlet mixing tank is rectified. Equal means that the direction of flow is the same. By the same flow direction turbulences are avoided, which can lead to an undesirable mixing of clear water and sludge.

According to an advantageous embodiment of the invention, a method for wastewater treatment is proposed in the sedimented sludge an aerobic, anoxic or anaerobic operated sludge aftertreatment basin is fed and runs through displacement due to the sludge supply higher-lying sludge water from the sludge aftertreatment tank. In such an operation, the sludge aftertreatment tank can be realized inexpensively, in particular without turbid water drainage device. Also, this is possible in terms of energy consumption economical operation.

According to further advantageous developments of the invention, the following is provided:

Wastewater treatment plant of the type described above, wherein the reaction and sedimentation basin has at least one further reaction section for the reaction treatment of the basin contents. Wastewater treatment plant of the type described above, wherein the first basin section is connected to the second basin section via a flow reduction device.

Wastewater treatment plant of the type described above, wherein the first connection point is connected to a first distribution device arranged in the first basin section and / or the second connection point is connected to a second distribution device arranged in the second basin section. Wastewater treatment plant of the type described above, wherein the first distribution device and / or the second distribution device is designed as a manifold.

Wastewater treatment plant of the type described above, wherein the inlet mixing basin is at least partially disposed in an area surrounded by the reaction and sedimentation basin. Wastewater treatment plant of the type described above, wherein the sludge aftertreatment basin is at least partially disposed in an area surrounded by the reaction and sedimentation basin.

Wastewater treatment plant of the type described above, wherein the inlet mixing basin a storage tank is connected upstream.

Wastewater treatment plant of the type described above, wherein the first and / or the second connection point is at least partially vertically extending shaft-like.

Wastewater treatment plant of the type described above, wherein the first and the second conveyor is arranged in a vertical wall of a shaft-like region of the first and the second connection point.

Wastewater treatment plant of the type described above, wherein in the inlet mixing basin, the combined reaction and sedimentation basin and / or the sludge aftertreatment basin at least one ventilation device and / or a mixing device is provided.

Process of the type described above, wherein clear water is removed from the reaction and sedimentation tank via a clear water outlet located in the sedimentation section.

Method of the type described above, wherein a temporally overlapping removal of clear water from the reaction and sedimentation basin and return of return sludge from the reaction and sedimentation basin in the inlet mixing basin takes place. Method of the type described above, wherein a temporally overlapping supply of wastewater to be cleaned in the reaction and sedimentation basin and return of return sludge from the reaction and sedimentation basin in the inlet mixing basin takes place.

Method of the type described above, wherein a removal of clear water from the reaction and sedimentation sediment basin and a return of return sludge from the reaction and sedimentation tank in the inlet mixing tank is rectified.

The invention will be explained in more detail by means of embodiments using drawings.

Show it

Figure 1 - a first embodiment of the wastewater treatment plant from a bird's eye view in plan view and

Figure 2 - a section of the wastewater treatment plant of FIG. 1 in a side sectional view and

FIG. 3 shows a further detail of the wastewater treatment plant according to FIG

Fig. 1 in a side sectional view and Figure 4 - another section of the wastewater treatment plant according to

Fig. 1 in side sectional view and

Figure 5 - another embodiment of the wastewater treatment plant from a bird's eye view in perspective view and

Figure 6 - another embodiment of the wastewater treatment plant the bird's eye view in top view and

Figure 7 - another embodiment of the wastewater treatment plant from a bird's eye view in plan view.

In the figures, like reference numerals are used for corresponding elements.

The wastewater treatment plant according to FIG. 1 has an inlet channel 30, via which wastewater to be purified is supplied, for example, from the sewage system and possibly after a primary clarification. The inlet channel 30 is connected via a connection point 80 with a reservoir 8. The storage tank 8 is used for collecting and buffering the supplied wastewater when the influx of wastewater temporarily exceeds the capacity of the Abwasserreinigungsan- plant. If necessary, wastewater can be withdrawn from the storage tank 8 at any time.

The inlet channel 30 opens via a connection point 40 into an inlet mixer 3. The junction 40 can be arranged in height so that it is above a desired for the operation of the wastewater treatment plant liquid level of the inlet mixing basin 3.

The inlet mixing basin 3 is connected via a first connection point 11 and a second connection point 21 to a reaction and sedimentation basin 1, 2. The reaction and sedimentation basin 1, 2 has, according to the embodiment of FIG. 1, a plurality of basin sections. A first basin section 1 is connected to the first connection point 11 and arranged in the region of the first connection point 11 next to the inlet mixing basin 3. At another point of the inlet mixing basin, advantageously on the opposite side of the inlet mixing basin 3, a second basin section 2 is provided, with the second connection point 21 is connected and is arranged in the region of the second connection point 21 adjacent to the inlet mixer 3. The first basin section 1 is followed by a reaction section 14. At these a connecting channel 6 connects. Connected to the connecting channel 6 is a reaction section 24. The reaction section 24 adjoins the second basin section 2. The basin sections 1, 14, 24, 2 and the connecting channel 6 are connected to each other, so that supplied wastewater in a certain flow direction, which is determined depending on the operating phase of the wastewater treatment plant, from the first basin section 1 to the second basin section 2 and vice versa can.

The first connection point 11 and the second connection point 21 are formed as a distributor shaft which runs at least partially vertically and can run vertically at least partially over the height of the inlet mixing basin or over the height of the first or the second basin section 1, 2. In a vertically extending wall 18, 28 of the respective distribution shaft 11, 21, a respective propeller pump 12, 22 is arranged. The propeller pump serves to convey return sludge from the first or the second basin section into the inlet mixing basin 3. The pump 12, 22 can also be operated in the reverse direction of operation. In this case, the pump 12, 22 conveys the mixture of sewage and activated sludge from the inlet mixer 3 into the first and second basin sections 1, 2, respectively.

Between the first basin section 1 and the reaction section 14, a first flow reduction device 15 is provided. Analogously, a second flow reduction device 25 is provided between the second basin section 2 and the reaction section 24.

The respective distributor shaft 11, 21 opens into a distributor tube 16, 26 arranged in the respective basin section 1, 2 near the bottom. The distributor tube 16, 26 distributes wastewater from the inlet mixing basin into the Reaction and sedimentation of the incoming wastewater evenly at the bottom of the reaction and sedimentation tank 1, 2. In a return sludge from the reaction and sedimentation basins 1, 2 in the inlet mixing basin, the return sludge is sucked via one of the Verteilererroh- re 16, 26 and over the respective distribution shaft 11, 21 returned to the inlet mixing tank 3.

The reaction and sedimentation tank 1, 2 can be operated in two flow directions. In a first flow direction, which is assumed in a first operating phase of the wastewater treatment plant, the first basin section 1 is the reaction section and the second basin section 2 is the sedimentation section. In a second operating phase of the wastewater treatment plant, the first basin section 1 is the sedimentation section and the second basin section 2 is the reaction section. In the reaction section, the biological wastewater treatment is carried out. In the reaction section according to the respective design and operation of the wastewater treatment plant z. B, the carbon compounds biodegraded, ammonium nitrified and / or denitrified nitrate. The operation of the first downstream section of the reaction and sedimentation tanks 1, 2 is switched in batches by the reaction, i. biological activity for purification of waste water, sedimentation. After a change in the direction of flow, that portion of the basin which previously had the function of e.g. carbon removal, denitrification and / or nitrification, the function of sedimentation.

In the pelvic section which is used as a sedimentation section, the possibly existing aeration devices and mixing devices, eg agitators, are switched off. The activated sludge sediments then. Directly when changing over the flow direction or after a sedimentation time, return sludge is conveyed into the inlet mixing basin 3 via the associated distributor pipe 16, 26 by means of the associated pump 12, 22. The first and second basin sections 1, 2 each have an associated clear water outlet 13, 23. The clear water outlet 13, 23 is located in the upper basin area and serves to remove the purified waste water, ie the clear water. The clear water outlet 13, 23 may be connected to the first and the second basin section 1, 2 via an openable connection point 19, 29, for example a lowering slide or a height-adjustable weir. The clear water is thereby removed from that basin section of the reaction and sedimentation basin 1, 2, which acts as a sedimentation section depending on the operating phase. After a certain period of sedimentation, clear water is removed via the clear water outlet 13, 23 via a pipeline 9.

Figure 2 shows in side sectional view, e.g. along the line C in Fig. 1, the connection between the inlet mixer 3 and the first basin section 1. The connection between the inlet mixer 3 and the second basin section 2 is made comparable. Visible is the propeller pump 12, 22 installed in a vertically extending wall section 18, 28 of the distribution shaft 11, 21 as well as the distributor pipe 16, 26 provided with openings, which is arranged near the bottom in the first or in the second pool area 1, 2 , Advantageously, the pump 12, 22 arranged in the vertical direction slightly higher than the junction of the distribution shaft 11, 21 to the first and second pool area 1, 2. This mixture is achieved in the inlet duct and the installation of the pump 12, 22 is simplified , By switching on the pump 12, 22, return sludge can be fed back into the inlet mixing basin 3 from the pool area 1, 2 operated as a sedimentation section.

By the arrangement of the manifold 16, 26, or more generally the junction 11, 21, and the overlying clear water outlet 13, 23 in the same basin area of the reaction and sedimentation basin a rectified flow arises from the reaction section into the sedimentation section. The rectified flow avoids turbulence. This allows a particularly effective sedimentation. FIG. 3 shows part of the reaction and sedimentation basin in a lateral sectional view, eg along the line A or B in FIG. 1. The distributor pipe 16, 26 arranged near the bottom and the clear water outlet 13, 23 arranged in the upper tank area can be seen Openable connection point 19, 29, which can be designed, for example, as a flap, drop gate or height-adjustable weir, can be taken from the upper tank area of the sedimentation section of clear water via the pipeline 9.

FIG. 1 also shows a mud aftertreatment basin 7 which lies in the area surrounded by the inlet mixing basin 3, the reaction and sedimentation basins 1, 2, the reaction sections 14, 24 and the connection channel 6. The sludge aftertreatment basin 7 is connected via respective feed pipes 17, 27 to the reaction and sedimentation basins 1, 2. The feed pipes 17, 27 lead from the reaction and sedimentation tank 1, 2 to the bottom of the sludge aftertreatment basin 7. In this case, the feed pipes 17, 27 can be led over, for example, over the upper edge of the tank or led through the tank wall. The feed pipes 17, 27 are used to supply sludge to the sludge aftertreatment basin 7. For this purpose, corresponding pumps are provided in the feed pipes 17, 27. The sludge can also be removed during the sedimentation phase of the connected pool part from the connection shaft 11, 21. In addition to the feed pipes 17, 27, further sludge removal devices can be arranged in the reaction and sedimentation basins 1, 2 for feeding sludge to the sludge after-treatment tank 7. In anaerobic operation, the sludge aftertreatment basin 7 is formed closed at its top and equipped with a vent for sewage gas. The sludge aftertreatment basin has a discharge line 10 for the removal of excess sludge. The sludge aftertreatment basin 7 is also connected to the inlet mixing basin 3 via a connection point 72. In non-anaerobic operation, an overflow to the inlet mixing basin 3 may be provided at the upper edge of the pool instead of the connection point 72. FIG. 4 shows a detail of the connection between the inlet mixing basin 3 and the sludge aftertreatment basin 7 in a lateral sectional view in anaerobic mode of operation. As can be seen, the feed pipe 17 or 27 extends in the sludge aftertreatment basin 7 in a substantially vertical direction and ends at an outlet point 71 in the bottom area of the sludge aftertreatment basin 7. In the sludge aftertreatment basin 7, the sludge accumulates from the bottom of the pool with decreasing density. The feeding of the sludge aftertreatment basin takes place after a sedimentation phase in the sludge aftertreatment basin. In the upper area, so-called sludge water is formed, ie water with a relatively low sludge content. When feeding the sludge aftertreatment basin 7 with excess sludge, the sludge water is displaced into the inlet mixing basin 3. When the muddy water in the

Sludge aftertreatment tank 7 exceeds a certain level, it flows through a junction 72, which is closable via a check valve 73, in the inlet mixing tank 3. Otherwise, the inlet mixing tank 3 is separated from the sludge aftertreatment basin 7 relative to the sludge aftertreatment basin 7 by the non-return valve 73 closed by the water pressure in the inlet mixing basin , The water level in the sludge aftertreatment basin 7 may be lower due to the gas pressure than in the inlet mixing basin, but is to be limited to a minimum water level 74 above the connection point 72, to an outflow of the gas through the joint 72 to prevent.

The return of the sludge water from the sludge aftertreatment basin can also be carried out directly into an adjacent area of the reaction and sedimentation basin 1, 2.

The contents of the sludge aftertreatment basin may be heated in an anaerobic mode to increase efficiency. For this purpose, a heating device can be arranged in the sludge after-treatment tank 7 or the supplied sludge can be heated.

The economy of the wastewater treatment plant can be further increased by adding into the sludge aftertreatment basin 7 pre-treatment sludge, external sludge or other organic substrates. Especially in this case, it is additionally advantageous to provide a scum drain in the sludge aftertreatment basin over which

Floating sludge can be removed. There may also be provided a means for preventing scum formation. FIG. 5 shows a further embodiment of the wastewater treatment plant according to the invention. As can be seen, the distribution chutes 11, 21 are guided to the upper edge of the inlet mixing basin 3 and open at the top. In addition, various lines of a ventilation system are shown. FIG. 1 also shows a control device 5 for controlling the actuation of the first and the second pump. The control device can be designed, for example, for simple switching on and off of the pumps via relays. It is also conceivable actuation of the pump via frequency converter or a phase control to operate the pump regulated, ie with adjustable pump power to operate. In particular, regulation of the liquid pumped by the pump can be dependent on be provided by operating parameters of the wastewater treatment plant.

6 shows a further embodiment of an inventive Ab- water purification system, which apart from the elements described below otherwise corresponds to the embodiment of Figure 1. The wastewater treatment plant is shown in detail in FIG. 6 such that the inlet mixing basin 3 and the first and second basin sections 1, 2 of the reaction and sedimentation basin are completely recognizable.

A third connection point 31 is arranged between the inlet mixing basin 3 and the first basin section 1 in the lower basin area of the first basin section 1. The third connection point 31 advantageously connects the basins in the vicinity of the bottom 4 of the reaction and sedimentation basin. In an analogous manner, a fourth connection point 41 is arranged between the inlet mixing basin 3 and the second basin section 2 in the lower basin area of the second basin section 2. The third and the fourth connection point 31, 41 may have a comparable construction as the first and the second connection point 11, 21, in particular they may be designed in the form of a respective connection shaft. The third and the fourth connection point 31, 41 have a respective pump 32, 42, which can advantageously be arranged in a vertical wall 38 or 48. Furthermore, the third connection point can be connected to a third distributor device 36 and the fourth connection point 41 to a fourth distributor device 46. The distribution devices 36, 46 may be formed as distribution pipes. The distributor devices 36, 46 are advantageously arranged in the vicinity of the bottom 4 of the respective bowl section 1, 2.

In the embodiment according to FIG. 1, the pumps 12, 22 are arranged in a wall section of the distributor shaft 11 or 21, which points away from the connection point 40. This can improve mixing of the contents of the inlet mixing basin 3, in comparison with an arrangement of the pumps 12, 22 in facing wall section of the distribution shaft 11 and 21. In the embodiment of Figure 6, the pumps 12, 22, however, in facing wall sections of the distribution chutes 11 and 21 arranged. Correspondingly, the pumps 32, 42 are arranged in facing wall sections of the distribution shafts 31 and 41, which in turn has a favorable effect on the mixing of the contents of the inlet mixing basin 3 in the arrangement of the four distribution shafts according to FIG.

Instead of a pump, other components or methods of return mud delivery may be provided, e.g. Advantageously, a return sludge conveyance by means of air injection in an ascending pipe section. The distributor shaft 31, 41 can also be provided only for return sludge conveying and not for feeding. In such a case, the feed can take place via the distributor shaft 11, 21. It is also possible to provide a respective charging point for the supply of waste water to be purified from the inlet mixing basin 3 into the combined reaction and sedimentation basin 1, 2, e.g. in the form of an additional opening between the inlet mixer 3) and the first and the second basin section.

By using such additional connection points 31, 41, a more even supply of wastewater to be cleaned from the inlet mixing basin 3 as well as a return of return sludge to the inlet mixing basin 3 can be achieved, in particular in spatially very extensive basin sections 1, 2. Optionally, other connection points between the inlet mixer 3 and the reaction and sedimentation tanks 1, 2 are provided, which are advantageously distributed over the longitudinal extent of the respective basin sections 1, 2. FIG. 7 shows a further embodiment of a wastewater treatment plant according to the invention, in which, in addition to the elements already described with reference to FIG. 1, a primary clarifier 100, which is connected upstream of the inlet mixing basin 3, is additionally provided. In this case, the inlet channel for wastewater is designed as a feed point 30.

Claims

claims:

1. Wastewater treatment plant with

a) an inlet mixing basin (3),

b) a combined reaction and sedimentation basin (1, 2) with a first and a second basin section,

c) where

d) a first connection point (11) is arranged between the inlet mixing basin (3) and the first basin section (1) in the lower basin region of the first basin section (1), c2) a first conveying device (12) at the first connection point (11) is arranged, which is operable to promote return sludge from the first basin section (1) in the inlet mixing basin (3),

c3) a first clear water drainage point (13) is arranged in the upper basin region of the first basin section (1), and d) wherein

d1) a second connection point (21) is arranged between the inlet mixing basin (3) and the second basin section (2) in the lower basin region of the second basin section (2), d2) a second conveying device (22) at the second connection point (21) is arranged, which is operable to promote return sludge from the second basin section in the inlet mixing basin (3), and

d3) a second clear water withdrawal point (23) in the upper pelvic region of the second pelvic portion (2) is arranged.

2. Wastewater treatment plant according to claim 1, characterized in that a first feed point (11) for supplying wastewater to be purified from the inlet mixing basin (3) into the combined reaction and sedimentation basin (1, 2) between the inlet mixing basin (3). and the first basin section (1) in the lower basin region of the first basin section (1) and a second feed point (21) for supplying wastewater to be purified from the inlet mixing basin (3) into the combined reaction and sedimentation basin (1, 2) between the inlet mixing basin (3) and the second basin section

(2) in the lower pelvic region of the second pelvic portion (2) is arranged.

3. wastewater treatment plant according to claim 2, characterized in that the first connection point (11) at the same time the first charging point and / or the second connection point (21) at the same time the second charging point.

4. Wastewater treatment plant according to at least one of the preceding claims, characterized in that a control device

(5) is provided for controlling the actuation of the first and the second conveyor (12, 22), which is adapted to either the first or the second conveyor (12, 22) or, for a short compared to the duration of the sedimentation period To operate over time, both conveyors (21, 22) for the promotion of return sludge from the reaction and sedimentation tank (1, 2) in the inlet mixing basin (3).

5. Wastewater treatment plant according to at least one of the preceding claims, characterized in that the reaction and sedimentation basin (1, 2) has a reaction section for the reaction treatment of the basin content and a Sedimentationsabschnitt for at least temporarily simultaneous sedimentation of the basin content.

6. wastewater treatment plant according to claim 5, characterized in that a) in a first operating phase of the wastewater treatment plant, the first basin section (1) is the reaction section and the second basin section (2) is the sedimentation section, and

b) in a second operating phase of the wastewater treatment plant, the first basin section (1) of the sedimentation section and the second

Basin section (2) is the reaction section.

7. Wastewater treatment plant according to at least one of the preceding claims, characterized in that the reaction and sedimentation tank (1, 2) via a further connection point (17, 27) with a sludge aftertreatment basin (7) is connected.

8. wastewater treatment plant with an aerobic, anoxic or anaerobic operated sludge aftertreatment basin (7) with biological activity, in particular wastewater treatment plant according to at least one of the preceding claims, with a lower pelvic area of the

Sludge aftertreatment basin (71) and a muddy water drainage point (72) or a muddy water overflow located in an uppermost basin area of the sludge aftertreatment basin.

9. Wastewater treatment plant according to claim 8, characterized in that the sludge water discharge point (72) is connected to a reaction and sedimentation basin (1, 2) and / or an inlet mixing basin (3).

10. wastewater treatment plant according to claim 8 or 9, characterized in that the sludge water discharge point (72) on the

Sludge supply point (71) opposite side of the sludge aftertreatment basin (7) is arranged.

11. A method for wastewater treatment, in particular method for operating a wastewater treatment plant according to at least one of the preceding claims, wherein the wastewater to be purified only one inlet mixing basin (3) and then a combined reaction and sedimentation tank (1, 2) is supplied, wherein in an operating phase of

Wastewater treatment plant to be cleaned wastewater the reaction and sedimentation tank (1, 2) via a first in the lower basin area of the reaction and sedimentation basin (1, 2) arranged feed or connection point (11) is supplied and in the lower Beck range of the reaction - And sedimentation basin arranged

Junction (21) Return sludge from the reaction and sedimentation tank (1, 2) in the inlet mixing basin (3) is guided.

12. The method according to claim 11, characterized in that in another phase of operation of the wastewater treatment plant the reaction and sedimentation tank (1, 2) is operated in the reverse flow direction, such that to be cleaned wastewater the reaction and sedimentation tank (1, 2) on the second Junction (21) or a second feed point is supplied and at the first connection point (11) return sludge from the reaction and sedimentation basin in the inlet mixing basin (3) is guided.

13. The method according to claim 11 or 12, characterized in that the first connection point (11) at the same time the first loading point and / or the second connection point (21) is at the same time the second loading point.

14. The method according to claim 12 or 13, characterized in that a portion of the reaction and sedimentation basin (1, 2) as a reaction section for the reaction treatment of the basin contents and another a portion of the reaction and sedimentation basin (1, 2) is operated as Sedimentationsabschnitt for at least temporarily simultaneous sedimentation of the basin content, the reaction section and the Sedimentationsabschnitt change depending on the operating phase of the wastewater treatment plant.

15. A method for wastewater treatment, in particular method for operating a wastewater treatment plant according to at least one of the preceding claims, wherein the sedimented sludge an aerobic, anodic or anaerobic operated sludge aftertreatment basin (7) is supplied with biological activity and by displacement due to

Sludge feed higher-level sludge water from the sludge aftertreatment tank (7) expires.