DE102005036364B4 - Device for extracting process water - Google Patents

Abstract

Device (1) for extracting solid-laden process water from a sedimentation tank (10) of a sewage treatment plant, having the following features:
a. a trigger line (30), the
i. at its first end (32) forms a suction opening (34) for process water,
ii. is intended to be introduced into the sedimentation basin (10) with the first end (32),
iii. at its second end (36) is connected to the pump (20),
b. a pump (20) for extracting solid-laden process water from the sedimentation basin (10) connected to the withdrawal conduit (30),
c. a probe (40) for detecting the solids content or a quantity equivalent to the solids content in the process water sucked in by the pump (20),
d. a lifting device (50) which is provided to set the height of the suction opening (34) of the withdrawal line (30) in the sedimentation basin (10),
characterized in that
e. the device (1) further comprises a measuring section (60) which
i. designed as a line section ...

Description

object The present invention is an apparatus for the removal of solids contaminated process water from a sedimentation tank of a sewage treatment plant.

in the Framework of wastewater treatment in a biological wastewater treatment plant goes through the wastewater to be treated has a plurality of purification stages, in which using various cleaning techniques dirt and pollutants are removed from the sewage to make it from a secondary clarifier as backwash water the natural water cycle feed again. Different treatment levels are based on a sedimentation of suspended matter from the treated Water in a sedimentation step, for which the wastewater is a sedimentation basin in which the wastewater to be treated in the rule a very low flow rate having. In this sedimentation settling process takes place, in which the suspended matter in the water under the influence of gravity sink and settle at the bottom of the sedimentation basin accumulate. Examples of this are the already mentioned secondary clarifier or arranged before and after the digester pre- or Nacheindicker.

Especially in the field of pre- and Nacheindicker the technical Task, the water above the sediment, which often still a fairly high level of pollution with suspended or pollutants , a re-treatment in upstream treatment stages supply. For this purpose, the above-sediment is in operation Process water over deducted a discharge line by means of a pump and an upstream clarification stage fed. The intake opening the discharge line is variable in height, often such that the height changed by means of a lifting device can be. By suitable techniques, the height of the intake opening of the Discharge line in the sedimentation tank adjusted so that the sucked Process water has a suspended solids content, which is a pre-set Limit does not exceed. In a sedimentation process that is conducted close to equilibrium, the suspended matter content is an immediate function of the height of the suction opening in the Sedimentation basin. exceeds the suspended matter content of the over the withdrawal line withdrawn process water the preset Limit value, then the suction port the trigger line lifted by the lifting device until the default Limit is fallen below again.

was standing the technique for detecting the suspended matter content of the withdrawn Process water is at the suction port of the pumping line, the always in the wastewater to be treated in the sedimentation tank, To arrange a probe, which is intended to the solids content in the sewage in the immediate vicinity of the suction port too to capture. Suitable for this are z. B. under the name "Liquisonic" from Sensotech GmbH, Magdeburg Barleben, Germany offered probes on an ultrasonic analyzer based and, for example, the density of the surrounded liquid Capture medium. Typical unit here is the "turbidity unit TE" in "Formacin" (TE / F).

There in the sedimentation tank of sewage treatment plants to be treated wastewater often very high suspended matter concentrations up to coarse mechanical Have impurities, the suction port of the trigger line must add arranged nearby Probe effectively protected against contamination. For this purpose, the Intake opening of the Discharge line and the probe frequently provided with a protective cage, in the practical operation of a sewage plant dependent the degree of pollution of the wastewater to be treated in more or less short distances must be cleaned. For such a cleaning, the drain line together with probe and protective basket completely from the sedimentation basin be removed. This is on the one hand with high staff effort and on the other hand with a risk that the sensitive Probe damaged or even destroyed becomes.

From the DE 297 10 398 U1 is a device for removing purified water from a container in the biological purification of wastewater by means of a pump known. In particular, reference is made to various types of pumps and discharge lines, which are suitable for the removal of water.

In the DE 101 48 474 A1 A biological wastewater treatment plant for the purification of wastewater generated in paper mills is described. Not all of the bio-sludge-water mixture running out of the activation stage is supplied to the post-clarification tank, but only part of it. The other part is treated in a parallel process step in a dewatering aggregate, which may be a sedimentation plant. The treatment of the wastewater activated sludge mixture in the sedimentation plant is preferably regulated automatically. For this purpose, a suitable measuring device (eg turbidity / solid-state probe) is connected downstream of the sedimentation plant for measuring the solids content of the purified wastewater. Furthermore, a control device is provided, which controls the metering device as a function of the solids content measured in the measuring device.

The DE 196 35 005 A1 discloses a process for the treatment of contaminated wastewater in a reaction tank in which the pollutant flakes settle to the bottom as sediment. The upper part of the wastewater is then examined for its turbidity. This can be done, for example, by taking a liquid sample in a predetermined fill level from the reaction tank by means of a pipeline, which then flows through a turbidity meter outside the basin. If the first turbidity limit value is not reached, the treated wastewater is sent to a collection basin.

From the DE 33 44 275 A1 a method and a device for the treatment of wastewater are known, wherein in a diverted part of the wastewater, a load-specific wastewater parameters, eg. As the turbidity is measured and flocculant is supplied in dependence on the measured parameter.

So a partial stream of the wastewater is pumped into a measuring section. In The measuring section is a means for measuring the turbidity provided.

The DE 74 39 432 U1 Finally, describes a rest basin with a device for monitoring and controlling the Schwebstofffreiheit of rest basin overflow liquid in mechanical separation processes for liquid-solid phases. Below the overflow of the pool is a liquid extraction line in the side wall of the pool, which merges outside the pool in a free fall distance. There is a turbidimeter arranged. The control units to control the Schwebstofffreiheit can not pollute, since the measuring section outside the resting pool arranged.

task It is therefore the object of the present invention to provide a triggering device of polluted process water from a sedimentation tank a sewage treatment plant specify the extended cleaning intervals at the same time increased Life of the probe used for turbidity measurement has.

Is solved this object by a device according to the main claim.

A inventive device for the deduction of polluted process water from a sedimentation basin a sewage treatment plant has a discharge line, which at its first end an intake for process water formed. The first end is therefore intended to be defined Height in to be introduced to the sedimentation basin. Furthermore, in the Discharge line A pump for the withdrawal of polluted process water inserted from the sedimentation basin. Farther is a probe for detecting the solids content or a for Solids content equivalent in size of provided the pump sucked process water. Furthermore, one is Lifting device, which is intended to the height of the intake opening of Set the discharge line in the sedimentation basin in a controlled manner.

According to the invention is now in the withdrawal line outside the sedimentation tank arranged a measuring section, wherein the probe for detecting the solids content in the sucked by the pump Process water on the outside the sedimentation basin formed measuring section is arranged.

The inventive device for the deduction of polluted process water realized several Advantages. By looking at a turbidity measurement or a measurement of the solids content in the intake process water is omitted within the sedimentation tank, usually on a probe in explosion-proof Version omitted Be there the outside the sedimentation basin trained measuring section in sufficient Distance of the usually explosive atmosphere, the surrounding the sedimentation basin, can be arranged. Farther Maintenance of the probe in a much easier way than in the previously known from the prior art device, since the outside the Sedimentierbeckens arranged measuring section an immediate Access to the probe is made possible by maintenance personnel. In addition, the arrangement offers the probe outside the sedimentation basin has the advantage that the sensitive probe of the still necessary cleaning work on the filter basket, which the suction opening the drain line surrounds, is no longer affected. Also, the Cleaning intervals compared the device known from the prior art is extended, because contamination of the filter basket at the intake of the Discharge line only the flow resistance along the Deduction line increased, but no longer has any negative influence on the turbidity or Fatty substance content measurement has. In this way, a higher degree of contamination the suction basket can be accepted without the control of the process water discharge from the sedimentation basin in affected is pulled.

In the device according to the invention, the measuring section is designed so that it is protected against dry traps. This can be achieved in particular in that the measuring section is formed as a gedückerter line section. As gedückerter line section, a line section is referred to, one compared to the level Having the remaining discharge line lowered area. By protecting the measuring section against dry traps, it can be ensured that the probe arranged in the region of the measuring section, which is preferably based on optical measuring methods, is not stubbornly soiled by dried solids from the process water during dry falling of the withdrawal line.

The Everyday usability of the device according to the invention in particular when used in northern Widths can be increased significantly be formed by the measuring section is heated. Especially is it possible to in the range of the measuring section electrically heated elements and a temperature monitoring to install. The temperature monitoring controls the heating elements when falling below a preset Minimum temperature, so that the temperature of the measuring section and especially the process water located in the measuring section at least one preset threshold corresponds. A heatability On the one hand, the measuring section offers the advantage of freezing the measuring section and / or the probe can be safely avoided. About that but there are also probes for measuring the solids content, whose results are clearly different from the temperature of the analyzed one Depend on process water. In such a case, the measurement accuracy of the probe can be improved when the temperature of the process water analyzed by the probe preferably is kept constant at a known value.

Of the Protection against freezing as well as the thermal stabilization of the process water to be analyzed can still be improved when the measuring section is formed thermally insulated. This can in particular by a double-walled design of the process water Cables can be achieved in the area of the measuring section.

Further Benefits arise when the device in addition to the inventively provided Measuring section forms a transparent inspection section, which allows a visual inspection of the sucked in process water. In this way, the operator of the sewage treatment plant is next to the result of the process water analysis performed by the probe also a direct visual inspection possibility of the withdrawn process water to disposal. This can be particularly advantageous to possibly malfunction to recognize the probe immediately.

• 1. Erfassen des Feststoffgehalts TS (ist) im von der Pumpe angesaugten Prozesswasser mittels der Sonde,
• 2. Vergleichen des erfassten Ist-Feststoffgehalts TS (ist) mit einem voreingestellten Soll-Feststoffgehalt TS (soll),
• 3. Anheben der im Sedimentierbecken angeordneten Ansaugöffnung der Ab zugleitung mittels der Hubvorrichtung um einen voreingestellten Wert Δh wenn TS (ist) größer ist als TS (soll), und
• 4. Absenken der im Sedimentierbecken angeordneten Ansaugöffnung der Abzugleitung mittels der Hubvorrichtung um einen voreingestellten Wert Δh wenn TS (ist) kleiner ist als TS (soll).

In an advantageous development of the device according to the invention, this comprises a control unit for the automated withdrawal of solids-laden process water from the sedimentation basin, wherein the control unit is arranged for the cyclical execution of the following method steps:

• 1. Detecting the solids content TS (is) in the process water drawn in by the pump by means of the probe,
• 2. comparing the detected actual solids content TS (ist) with a preset desired solids content TS (soll),
• 3. Lifting of the sedimentation tank arranged in the intake port of the train line by means of the lifting device by a preset value .DELTA.h if TS (is) is greater than TS (soll), and
• 4. Lowering the sedimentation tank arranged in the suction port of the discharge line by means of the lifting device by a preset value .DELTA.h if TS (is) is smaller than TS (soll).

A corresponding control unit, for example, as a freely programmable PLC unit executed with the preset target solids content TS (should) as well as the step size Δh the height adjustment adjusted to the conditions of the treatment stage, in the device of the invention is used.

Especially preferred is the use of the device according to the invention for the deduction of Feststoffbelastastetem Process water from the sedimentation basin in front of the digester sewage plant arranged Voreindickers or from the sedimentation of a behind the digester of the sewage treatment plant arranged Nacheindickers.

Farther the use of a device according to the invention is particularly preferred for deduction of solids loaded process water from a sedimentation tank a sewage treatment plant in the event that explosive gases form in the sedimentation basin can, so that the sedimentation basin surrounded by an explosion protection zone is. Due to the structure of the device according to the invention, it is possible to Measuring section outside to arrange the explosion protection zone. This makes it possible to explosion-proof versions to dispense with the probe. In the hitherto conventional in the art generic device had the probe is mandatory in the hazardous area, ie in the Explosion protection zone can be arranged. So far, it has been necessary for the Probe an explosion-proof execution to use, which increased the cost of the generic device.

Further Features and advantages of the device according to the invention and advantageous uses emerge from the dependent claims as well as the following embodiments, which are explained in more detail with reference to the drawing. In this show:

1 : a schematic representation of a device according to the invention in side view,

2 : a schematic representation of the measuring section of the device according to the invention 1 .

3 : an enlarged view of the measuring section 2 with inserted probe,

4 : a front view of the probe 3 .

5 an enlarged section through the measuring section of a device according to the invention in an alternative embodiment, and

6 : A schematic representation of arranged in the field of digester of a biological treatment plant Klärstufen.

1 shows a device according to the invention 1 , which is located at the sedimentation of a Nacheindickers, a biological wastewater treatment plant, which is located in the wake of the digester of the sewage treatment plant. The sedimentation basin is with 10 and is filled with solids contaminated water, which was withdrawn from the digester, filled. In the sedimentation basin, the water to be treated has only a low flow velocity, so that the solids entrained by the water sink to the bottom under the influence of gravity. Accordingly, it forms in the sedimentation basin 10 a ground-level, high-solids sediment (mud) layer 12 above, a process water layer that is only relatively weakly loaded with solids 14 formed. Both layers are separated by a transition layer 16 separated, in which a strong increase in the solids concentration as a function of altitude in the sedimentary basin 10 can be observed. The device according to the invention 1 is now intended to that in the upper layer 14 Process water from the sedimentation basin 10 withdraw and re-feed the purification process by recycling in an upstream clarifier. In this case, a preset maximum solids concentration in the recycled process water should not be exceeded.

Because that's the sedimentation basin 10 wastewater still carries biological solids, during the sedimentation process, decay processes continue, which can lead to the formation of explosive fouling gases. Therefore, in a certain radius around the sedimentary basin 10 an explosion protection zone 90 trained, within which electrical equipment may be used only in a special explosion-proof design.

The device according to the invention now comprises a discharge line 30 that with her first end 32 at which a suction opening 34 is formed and the means of a protective cage 38 is protected against the suction of coarse mechanical impurities in the process water layer 14 in the sedimentation basin 10 is introduced. Here is the front section 36 the withdrawal line 30 flexibly formed so that the height of the suction port 34 in the sedimentation basin 10 by means of a lifting device 50 can be varied within specified limits.

The lifting device 50 is as a crane with a boom 56 trained, at the top of a rope 54 the first end 32 the withdrawal line 30 with the intake opening 34 and the protective basket 38 is suspended. The rope 54 is deflected by two pulleys and by the cable drum of a drive 52 added. By means of the drive 52 then can the rope 54 be rolled up or down so that the height of the suction opening 34 in the sedimentation basin 10 can be set.

Am from the intake 34 opposite end of the flexible front section 36 the withdrawal line 30 is the flexible front section 36 with the later in the course designed as a metallic pipe withdrawal line 30 connected. The then metallic discharge line 30 is over the top cover of the sedimentation tank 10 led out and along the outside of the sedimentation tank 10 a pump 20 fed. This pump 20 sucks over the drain line 30 Process water from the sedimentation basin 10 to deliver this to an upstream clarification stage of the biological treatment plant.

In an advantageous alternative embodiment, the pump 20 also on the rope 54 suspended and immediately in the sedimentation basin 10 arranged. In this arrangement, it has been found to be particularly advantageous when the suction port 34 in the sedimentation basin 10 is oriented upwards.

Behind the pump 20 is in the trigger line 30 a measuring section according to the invention 60 formed in a housing 62 is housed and their structure is discussed in more detail below.

To the measuring section 60 Essentially, only the process water return line to the upstream clarification stage follows.

To control the device according to the invention is outside the explosion protection zone 90 of the sedimentation basin 10 a central control unit 5 arranged, which is an advertisement 7 and controls 9 having. The central control unit 5 is preferably a freely programmable PLC Control unit formed, which can be freely programmed according to the circumstances of the sewage treatment plant. In the embodiment shown, the display 7 provided by the at the measuring section 60 arranged probe 40 (in 1 not shown) recorded solids content via the withdrawal line 30 return process water (here: 0.075 g / l) and the recirculated flow of process water (here: 77.8 l / min.). The controls 9 are intended to provide certain control functions of the central control unit 5 be triggered or interrupted or the plant put into operation or out of service.

Furthermore, on the outside of the sedimentation tank 10 an inspection section 80 in the withdrawal line 30 trained for direct visual control of the over the drain line 30 recycled process water is used. In its simplest form is the inspection section 80 designed as a glass tube section through which a user directly on the in the trigger line 30 guided process water stream can look. For a user of the device according to the invention is based on staining and turbidity a malfunction of the probe 40 or the control unit 5 immediately recognizable.

2 now shows a section through the measuring section 60 which is downstream of the pump 20 in the withdrawal line 30 is arranged. The measuring section 60 consists essentially of a geduckerten pipe section, which inlet and outlet side with flanges 64 for connection to the withdrawal line 30 is provided. The geduckerte pipe section is bent at four positions by an angle β, so that there is a substantially U-shaped course of the angle β is preferably between 15 ° and 60 °, in particular at 45 °. In the area of the two unwound legs of the geduckerten pipe section are outside electrical heating sleeves 68 attached, which is electrically connected to the central control unit 5 are connected and are controlled by this, when attached to the geduckerten pipe section temperature sensor (not shown) indicates a temperature below a preset target temperature lying actual temperature.

Of the entire butted Pipe section is made of high-strength stainless steel, wherein the inner diameter of the pinned Pipe section is in the range of 10 cm. Of course they are other inner diameters possible, wherein the particularly suitable inner diameter substantially from the attributable per time expenditure Amount of process water is determined.

In the lowest-lying section of the geduckerten pipe section is an insertion opening on top 72 for a probe 40 provided for detecting the solids concentration in the recycled process water.

Furthermore, here is a vent 74 provided when stopping the pump 20 the turbid water withdrawal from the sedimentation basin 10 interrupts.

Like from the 3 and 4 becomes evident, the probe points 40 a substantially cylindrical housing with a front measurement window 44 on. The probe 40 is doing so in the access opening of geduckerten measuring section 60 pasted that with her measurement window 44 almost to the geduckerte the measuring section 60 protrudes through flowing process water flow.

The probe 40 is preferably based on an optical measuring method in which the backscatter intensity of in a measuring cone 46 irradiated infrared radiation is detected. Amongst other things, the process photometer offered under the name "Solitax RM3" for the measurement of turbidity and solid content of liquids, which is marketed by Dr. Bruno Lange GmbH & Co. KG, 40549 Dusseldorf, Germany, has proved its worth in practical applications The Solitax RM 3 probe Based on a combined infrared absorption scattered light method, which enables the detection of very low turbidity values according to DIN EN 27027 as well as the detection of high sludge contents.

In addition to the use of optical-based probes 40 Furthermore, it is also possible to use, for example, ultrasound-based probes. In addition, all probes suitable for use in the relevant turbidity or solids content range may be used 40 which are based on alternative measuring methods are used.

Im out 3 apparent embodiment includes the based on an optical measurement method probe 40 front a wiper 48 on, in which if necessary (possibly automated) the measurement window 44 can be cleaned. Furthermore, when out 3 apparent embodiment, the probe 40 arranged with its longitudinal axis substantially transversely to the flow direction of the process water in the geduckerten measuring section, so that the axis of symmetry of the measuring cone 46 also substantially perpendicular to the flow direction.

How out 3 Furthermore, it can be seen that the metallic pipe of the geduckerten pipe section is at least directly to the probe 40 adjacent area double-walled, wherein the area between the walls is evacuated and in this way the thermal Highly insulating vacuum chamber 66 formed. The combination of the electric heater 68 and the through the vacuum chamber 66 realized thermal insulation of the stowed test section 60 in the area of the probe 40 leads to an excellent freezing security of the device according to the invention.

An alternative arrangement of the probe 40 in the gedückerten measuring section 60 is out 5 seen. Here is the probe 40 essentially in the same place as in 2 apparent embodiment in the gedückerte Messstre bridge 60 inserted. In contrast to the embodiment according to 3 is now however the longitudinal axis of the probe 40 , which in turn may be of the aforementioned Solitax type, by an angle α against the flow direction of the in the geduckerten measuring section 60 flowing process water inclined. In particular, an angle between 90 and 180 ° is suitable here, wherein an angle of about 120 to 150 ° is preferred. How out 5 can be seen, then the measuring cone 46 against the flow direction of the process water in the geduckerten measuring section 60 inclined. Im out 5 apparent embodiment, the probe 40 not as in the embodiment according to 3 by means of a union nut 70 in the insertion opening 72 the gedückerten measuring section 60 fixed. Rather, the insertion opening forms 72 at its end a flange 64 out as well as the probe 40 , The probe 40 is then in the insertion opening 72 inserted and the two flanges 64 screwed together. In all embodiments, the probe 40 via a probe cable 42 with the central control unit 5 connected.

Out 6 are the at the digester 100 a biological cross-plant adjacent treatment stages shown schematically. The primary sludge that is the digestion tower 100 is fed, is in a pre-thickener 110 Process water withdrawn, which is fed via a return line to an upstream clarification stage. The from the digester 100 withdrawn sewage sludge is then in a Nacheindicker 120 again withdrawn process water, which in turn is fed via a return line to an upstream clarifier. Both the pre-thickener 110 as well as the Nacheindicker 120 have sedimentary tanks 10 and are therefore in principle for a use of the device according to the invention 1 suitable.

In a preferred embodiment, the central control unit 5 set up by the probe 40 detected solids concentration in the intake port 34 the withdrawal line 30 to determine the withdrawn process water. The central control unit 5 compares the measured actual value of the solids concentration TS (ist) with a preset setpoint TS (soll). If the measured actual value TS (ist) exceeds the preset nominal value TS (soll), then the central control unit is 5 to set up the suction port 34 the withdrawal line 30 by means of the lifting device 50 in a control step by the height Δh in the sedimentation tank 10 to raise. In this way, in the presence of an equilibrium sedimentation distribution, the solids concentration in the withdrawn process water decreases.

If the measured solids concentration TS (ist) in the withdrawn process water falls below the preset target value TS (soll) by more than a preset tolerance value ΔTS, the actual solids concentration in the withdrawn process water is at a level clearly above the acceptable value. That is, for a return of the process water, a higher solids concentration is justifiable. In this case, the central control unit 5 to set up the suction port 34 the withdrawal line 30 by a defined height step Δh in the sedimentation basin 10 lower.

The aforementioned process steps are cycled through at a repetition rate of a few cycles per 5 minutes to keep the solids concentration in the recirculated process water always in the range of the preset target value TS (soll). In particular, it is possible here to set the tolerance range ΔTS to the value zero, so that that from the central control unit 5 executed method leads to that of the device according to the invention 1 from the sedimentation basin 10 withdrawn process water substantially always has a solids concentration that coincides with the preset target value TS (soll).

1

contraption for the withdrawal of process water

5

central control unit

7

display

9

operating element

10

sedimentation basin

12

sediment layer

14

Process water layer

16

Transition layer

20

pump

30

withdrawal line

32

first The End

34

suction

36

flexible front section

38

protective cage

40

probe

42

probe cable

44

measurement window

46

measuring cone

48

windshield wipers

50

lifting device

52

drive

54

rope

56

boom

60

measuring distance

62

casing

64

flange

66

vacuum chamber

68

Heating jacket

70

Nut

72

insertion

74

vent

80

inspection section

90

Explosion protection zone

100

digester

110

prethickener

120

secondary thickener

Claims (9)

Contraption ( 1 ) for the removal of solids-loaded process water from a sedimentation basin ( 10 ) of a treatment plant having the following characteristics: a. a withdrawal line ( 30 ) i. at its first end ( 32 ) an intake opening ( 34 ) for process water, ii. is provided with the first end ( 32 ) into the sedimentation basin ( 10 ), iii. at its second end ( 36 ) with the pump ( 20 ), b. a pump ( 20 ) for the removal of solids-loaded process water from the sedimentation basin ( 10 ) connected to the withdrawal line ( 30 ), c. a probe ( 40 ) for the determination of the solids content or a quantity equivalent to the solids content in the pump ( 20 ) sucked in process water, d. a lifting device ( 50 ), which is intended to increase the height of the suction opening ( 34 ) of the withdrawal line ( 30 ) in the sedimentation basin ( 10 ), characterized in that e. the device ( 1 ) continue a measuring section ( 60 ) which i. is designed as a line section in the withdrawal line ( 30 ), ii. is provided outside the sedimentation basin ( 10 ), and iii. is designed to protect against dry traps and f. the probe ( 40 ) at the measuring section ( 60 ) is arranged. Device according to claim 1, characterized in that the measuring section ( 60 ) is formed as gedückerter line section. Device according to claim 1, characterized in that the measuring section ( 60 ) is formed heated. Device according to claim 1, characterized in that the measuring section ( 60 ) is formed thermally insulated. Device according to claim 1, characterized in that the probe ( 40 ) is designed to detect the solids content in the sucked process water by means of an optical measuring method. Device according to claim 1, characterized in that in the withdrawal line ( 30 ) a transparent inspection section ( 80 ) is formed, which allows a visual inspection of the sucked process water. Device according to claim 1, characterized in that the device further comprises a control unit ( 90 ) for the automated withdrawal of solids-laden process water from the sedimentation basin ( 10 ) arranged for cyclically performing the following method steps: a. Detecting the solids content TS (is) in the pump ( 20 ) sucked in process water by means of the probe ( 40 b. Comparing the detected solids content TS (ist) with a preset target solids content TS (soll), c. Lifting in the sedimentation tank ( 10 ) arranged suction opening ( 34 ) of the withdrawal line ( 30 ) by a preset value Δh when TS (is) is greater than TS (soll), and d. Lowering the sedimentation tank ( 10 ) arranged suction opening ( 34 ) of the withdrawal line ( 30 ) by a preset value Δh when TS (is) is less than TS (soll). Use of a device according to claim 1 for the extraction of solids-loaded process water from the sedimentation basin ( 10 ) one in front of the digester ( 100 ) of the treatment plant ( 1 ) arranged Voreindickers ( 110 ) or one behind the digester ( 100 ) of the treatment plant ( 1 ) arranged Nacheindickers ( 120 ). Use according to claim 8, characterized in that the sedimentation basin ( 10 ) from an explosion protection zone ( 90 ) is surrounded and the measuring section ( 60 ) outside the explosion protection zone ( 90 ) is arranged.