DE10262031A1 - Activated waste water treatment basin has pre-programmed pivoting wall-mounted sludge skimmer with sludge measuring sensor - Google Patents

Abstract

A waste water treatment plant has an activated sludge removal assembly which is esp. a swivel-mounted skimming assembly (20) which is attached (1) to the basin wall (19). The gutter skimming assembly has a moving frame (2) with a spindle (4) drive and drainage channel (5). The drainage channel has a front section (7) which is moves by a rod (13) and spindle (12), and has an inlet edge and a base (8) inclined towards the pump box (8), and a fixed rear wall. The angle of the drainage channel (5) can be adjusted with respect to the water surface by the spindle (4). The rate at which sludge is removed is regulated and adjusted by the spindle and rod. In a preferred embodiment the installation has a programmable regulator in which the skimmer is raised or lowered in accordance with sludge depth. Also a conductive sensor measures sludge thickness, breadth and height of the sludge bubbles.

Description

The invention relates to a device for floating sludge removal in wastewater treatment using the activated sludge process.

With biological wastewater treatment after The aerobic activated sludge process turns activated sludge into waste water suspended, in its flakes microorganisms in mixed cultures Life. The special design of the process ensures that that the particular Substances and the microorganisms are held in the flakes. The microorganisms largely utilize the organic wastewater constituents as well as the nutrients and multiply. After separating the sludge they are originally particulate contained in waste water and solved Substances largely eliminated. They were considered inert substances or metabolic products absorbed in the sludge or as gaseous metabolites into the atmosphere issued.

With increasing demands on the elimination of nutrients are the sewage treatment plants that use the activated sludge process due to the increased occurrence of expanded sludge, swimming sludge and Foam impaired in its function. Cause for that is the increased appearance or a real mass development of thread bacteria, e.g. microthrix parvicella, in the activated sludge.

The appearance of thread bacteria in the activated sludge can practically not be prevented. Their metabolism extends in line with the goal of wastewater treatment. Through a However, the high percentage of thread bacteria makes the flakes bulky Structure imprinted, so that activated sludge occupies a much larger volume than a sludge with relatively few thread bacteria. While under normal conditions of the sludge volumetric index all year round 100 ml / g dry matter remains, it lies in the sludge with a high proportion on thread bacteria by 150 ml / g and also much higher. Such activated sludge is called bulking sludge designated.

The hydrophobic surface properties of the thread-forming microorganisms result in them being collectors work for gas bubbles, that stick to them. Sludge with a high proportion of thread bacteria becomes on the surface enriched as a foam or floating sludge. It educates there a separate biocenosis with particularly cheap ones Growing conditions for Filamentous bacteria. According to the rules of technology, the swimming mud from the revitalization to the clarification be directed so that it through the mud scraper of the After clarification can be removed. As long as the floating mud clearance on the After clarification adequately works, swimming mud becomes an annoying but manageable phenomenon considered.

With the increased or mass appearance of thread bacteria is linked to that at the latest in the event of occurrence of expanded sludge the quality requirements the process from the wastewater treatment plant no longer met can be. As a rule, it occurs in situations of high hydraulic loads the sewage treatment plant first to the uncontrolled transition greater Amounts of activated sludge above the clear water in the receiving water, then it is enough in the circuit remaining amount of activated sludge is no longer sufficient to meet the required Compliance with elimination performance.

What they have in common is that their success often short-lived or not certain or permanent and requires high additional effort.

The use of special precipitants for controlling expanded sludge only works safely if it occurs continuously, so high Additional costs arise. An over longer Time effective destruction the thread bacteria due to liming of the whole sludge is due the temporarily unavoidable high load on the sewage treatment plant drain not allowed.

The mechanical removal of floating sludge from the aeration tank special devices is a method of getting the sludge too to reduce.

It is the object of the invention a device for floating sludge removal available put. The device is intended to be universal for continuous continuous systems and discontinuous SBR plants using the activated sludge process applicable and both for New buildings as well as retrofit solutions are available at low cost.

The object of the invention is achieved by a device for floating sludge removal with a removal device solved, which is particularly characterized in that the removal device is designed as a swiveling skimmrough and over a Recording is designed to be attachable to the pool wall and from a spindles and middle bearing movable frame and related Ditch gutter is constructed, the gutter consisting of an over one linkage and a spindle swiveling front part with leading edge and one to the pump box at an angle arranged floor and a fixed rear wall and that the Position of the drainage channel to the water surface adjustable via the spindles is and that the location of the leading edge and thus the amount removed the removal device over the spindle and the rod is adjustable.

According to a preferred embodiment the invention provides a programmable control device, with which the swiveling Skimmrinne over the measurement of the immersion depth the leading edge is traced to the different water levels.

The invention is equally advantageous if it is a programmable rule Direction is provided with which the swiveling Skimmrinne is regulated by measuring the thickness, width and height of floating mud flocks and a mud sensor working according to the conductive principle is provided for this purpose.

This creates a device the targeted enrichment and separation as well as the effective Removal of the light sludge enriched with thread bacteria allows.

More details, features and Advantages of the invention result from the following description of embodiments with reference to the related Drawings. Show it:

1 : Trigger device,

2 : Pre-classification,

3 : Side view, swiveling skim gutter with mud sensor,

4 : Mud sensor top view,

5 : Sludge sensor section AA.

In 1 and 2 is an inventive solution to the problem with a removal device in the form of a dynamically controlled and swiveling Skimmrinne 20 shown for continuously operating continuous systems.

The removal device is called Extractor for excess sludge and in every phase of the development of thread organisms as well for the removal of expanded and floating sludge used.

The removal device consists of a receptacle 1 that with the pool wall 19 is connected via a clamp connection or fastening elements. A clamp connection advantageously permits the operational use of the device.

The frame 2 the removal device is based on the central bearing 3 and the two spindles 4 from. With the help of the spindles 4 the horizontal position of the overflow edge of the channel can be set exactly to the water level, which is a prerequisite for a uniform immersion depth and a quantifiable deduction.

On the frame 2 is the gutter 5 and the pump box 6 attached. In the pump box 6 there is a float-controlled submersible pump or sludge pump that conveys the excess sludge into the sludge stack for post-treatment. The gutter 5 consists of a swiveling front part 7 and one to the pump box 6 sloping floor 8th , in 1 shown as a dashed line, and a fixed rear wall 9 , The leading edge 10 of the front part 7 is curved.

For adjusting the front part 7 serves an adjustable electric motor drive 11 with a spindle 12 and one to the front 7 connected linkage 13 , The control drive is mechanical, hydraulic or pneumatic.

The signals for regulating the swiveling front part 7 are measured by a level sensor 14 to the control device 16 given.

The function of the solution according to the invention is based on the targeted controllability of the removal of excess sludge after previous Classification of the flakes.

With the programmable control device 16 the operating regime of the excess sludge discharge is specified. Discharge and pause times, discharge quantities via immersion depth and the tracking of the inlet edge can be set 10 to the changing water level.

When removing excess sludge, the leading edge 10 of the swiveling channel front part 7 with the help of the control drive 11 placed under the water surface. The specified immersion depth determines the withdrawal quantity. The control variable required for this is via the level probe 14 determined.

In connection with the removal device, which in 1 is shown, the classifying device acts according to the invention 2 ,

One in front of and under the skim gutter 20 attached baffle 17 leads with the support of an air intake 18 for classifying light flakes enriched with thread organisms and heavy flakes with a small proportion of thread organisms.

Skimmrinne 20 and baffle 17 are placed in a place with a calm flow in the pool.

In the zone in front of the baffle 17 If the flow is calm, the flakes are pre-classified according to the principle of gravity, so that the heavier, "healthy" flakes flow under the baffle.

The lighter flakes move above the baffle 17 ,

The additional air intake 18 causes fine air bubbles to attach to the flakes with bulky thread organisms, which then rise upwards, in front of the skim gutter 20 collect and be deducted.

A special version of the extraction device is the "Floating sludge discharge" application. The application becomes effective when, due to the composition of the raw sewage and with conventional process management, bulk and expanded sludge and floating sludge develop. In this case, immediately before the gutter front part 7 a sludge sensor 15 attached, in the case of mud build-up via the control device 16 the control drive 11 starts.

The mud sensor 15 is in 3 to 5 represented and works according to the conductive principle.

In 3 is a swiveling skim gutter according to the invention 20 with back wall 9 , the swiveling front part 7 and the leading edge 10 in cooperation with the sludge sensor 15 shown. A frame element 21 of the sensor is with the swiveling front part 7 connected.

The mud sensor 15 is in 4 in the top view with the guides 22 for the conductive pencils 23 to see. The guides 22 are variably spaced from each other in the y direction. The connections of the guides are for this 22 on the frame elements 21 to train accordingly. The connections are preferably designed as a clamp connection in order to be able to implement even very small changes in position.

In 5 a section AA is shown, which the guides 22 and the conductive pins, which can be variably fixed thereon 23 shows. The conductive pins 23 are on the guides 22 adjustable in z-direction, which makes the distance between the pins 23 is adjustable to the water surface. Ultimately, the thickness of the floating sludge layer can be specified.

With sludge accumulations between those above the water surface and on two parallel guides 22 staggered conductive pins 23 a signal is triggered and sent to the control device 16 passed.

The pencils 23 are variably adjustable in three levels to adjust the sensitivity. Thus, the length, width and thickness of the sludge flakes on which the control device can be specified, for example by lowering the leading edge 10 , should react.

The setting of the inlet edge parallel to the water level 10 and the adjustable immersion depth of the channel front part 7 ensures a quantified sludge inflow into the skim gutter 20 ,

1

admission

2

frame

3

center bearing

4

spindle

5

discharge chute

6

pump box

7

front

8th

ground

9

rear wall

10

leading edge

11

drive

12

spindle

13

linkage

14

level sensor

15

mud sensor

16

control device

17

baffle

18

air entry

19

pelvic wall

20

swiveling Skimmrinne

21

frame element

22

guides

23

conductive pens

Claims (4)

Device for the removal of floating sludge with a removal device, characterized in that the removal device is designed as a pivotable skim gutter ( 20 ) is executed and via a recording ( 1 ) on the pool wall ( 19 ) is designed to be attachable and consists of a spindle ( 4 ) and middle bearing ( 3 ) movable frame ( 2 ) and related drainage channel ( 5 ) is constructed, whereby the discharge channel ( 5 ) from a via a linkage ( 13 ) and a spindle ( 12 ) swiveling front part ( 7 ) with leading edge ( 10 ) and one to the pump box ( 6 ) sloping floor ( 8th ) and a fixed back wall ( 9 ) exists and that the position of the drainage channel ( 5 ) to the water surface via the spindles ( 4 ) is adjustable and that the position of the leading edge ( 10 ) and thus the amount withdrawn from the removal device via the spindle ( 12 ) and the linkage ( 13 ) is adjustable. Device according to claim 1, characterized in that a programmable control device ( 16 ) is provided with which the swiveling skim gutter ( 20 ) by measuring the immersion depth of the leading edge ( 10 ) the different water levels are tracked. Device according to claim 1 or 2, characterized in that a programmable control device ( 16 ) is provided with which the swiveling skim gutter ( 20 ) is regulated by measuring the thickness, width and height of floating sludge jibs and a sludge sensor that works according to the conductive principle ( 15 ) is provided. Device according to claim 3, characterized in that the sludge sensor ( 15 ) from frame elements ( 21 ) is constructed and guides can be arranged variably in the y direction ( 22 ) and that on the guides ( 22 ) the conductive pins ( 23 ) can be variably arranged in the z direction and in the x direction.