DE10048309A1 - Small scale water treatment assembly has movable suction inlet discharging from one chamber to a second chamber - Google Patents

Abstract

A small-scale sequencing batch reactor water treatment assembly has an inlet to a pre-treatment chamber, an outlet to a biological treatment chamber, with a sediment return feed to the pre-treatment chamber. The treatment unit has a pneumatic pump (16,20) drawing water from either of the two chambers via especially a movable inlet (16s), and discharging into the other chamber. A small-scale sequencing batch reactor water treatment assembly has an inlet to a pre-treatment chamber, an outlet to a biological treatment chamber, with a sediment return feed to the pre-treatment chamber. The treatment unit has a pneumatic pump (16,20) drawing water from either of the two chambers via especially a movable inlet (16s), and discharging into the other chamber. The pump (16,20) is a height-adjustable pneumatic telescopic pipe secured to a guide rail.

Description

The invention relates to a small sewage treatment plant for biological Wastewater treatment using the SBR process (SBR = Sequencing Batch Reactor). The term "SBR process" includes related Processes like the SBBR process (with additional Growth areas for microorganisms).

Irregular and is problematic for small sewage treatment plants uncontrolled wastewater inflow. At peak times, one must disproportionately large amounts of waste water are treated. It there is a risk that too much biomass from the system is rinsed out. Conversely, it can also take days or weeks Example during vacation times, the wastewater supply is reduced or be completely interrupted. This can lead to the Microorganisms in the plant are their livelihood  is withdrawn. The activated sludge technique is like that Fixed bed technology, based on the constant presence of a sufficient amount of microorganisms in the system. Unlike with sessile microorganisms like those on fixed beds colonize, have mobile microorganisms such as those found in Activated sludge processes only occur to a limited extent Possibility of surviving without constant supply of new substrate.

A lack of substrate supply (due to reduced or interrupted waste water supply) leads to a so-called Autolysis. The amount of sludge is drastically reduced and thus the active biomass, up to the complete "biological System "standstill. Are then increased again Waste water quantities fed into the plant, there is only one reduced cleaning performance available. In extreme cases it can there will be water pollution until the facility turns itself off regenerated.

The SBR process belongs to the category of aerobic activated sludge processes and is characterized by batch-wise, periodic operation. The main process steps are:

• - Finds in the wastewater discharged into the primary clarification chamber a first separation of coarser ones by sedimentation Solid particles instead.
• - The wastewater pre-cleaned in this way is batched into a biological cleaning chamber promoted and there under Air supply mixed. Waste water ingredients can be found under aerobic conditions are implemented biologically. The Setting anaerobic or anoxic conditions in this cleaning level is technically possible.  Basically, the duration and choice of Millie conditions can be designed freely. She will orientate on the pollution of the wastewater.
• - In a third stage, the ventilation and Mixing of the waste water switched off. suspended sink due to sedimentation and form one Mud phase that settles on the ground. The respective Biocenosis is dependent on numerous factors. Changes can increase or decrease the active Biomass in relation to the volume of biological Affect cleaning chamber. This relationship is through the so-called dry matter content (TS content) characterized. Over the mud phase lies the clarified clean sewage.
• - Part of the cleaned wastewater (the clear phase) is withdrawn from the system; becomes part of the mud phase as a so-called excess sludge from the reaction chamber returned to the primary clarifier for sludge stacking.

The invention has for its object a small sewage treatment plant of the type mentioned, which is largely independent of the amount of waste water supplied works and in particular even in times of low or interrupted wastewater supply remains functional.

The invention is based on the consideration that Modify small wastewater treatment plant in such a way that  in particular, the plant more or less wastewater works less independently. In other words: through constructive and / or changes in the control system should Supply of substrate-containing wastewater and its biological Treatment by a cycle of sewage and sludge in the plant at least to a reduced extent (compared to the Normal state) can be maintained.

Various concrete options are available for this:

• - Change the position (especially height) of a suction-side end of at least one delivery line for Return of wastewater and / or sludge from the Reaction chamber into the primary clarification chamber and / or from waste water and / or sludge from the pre-clarification chamber into the reaction chamber
• - SBR systems of known design have a fixed one Extraction point. This is exactly where the invention moves to Times when there is less waste water / sludge, for example the suction element in the primary clarification chamber lower and thus further microbiological substrate (Sludge) from the primary clarification chamber into the reaction chamber to be able to transfer. So it is targeted in the Pre-clarification stacked sludge partially used and as Substitute used for missing wastewater inflow. Alternatively or cumulatively, the extraction location in the Reaction chamber to be raised, if possible only To promote clear water in the primary clarification and the biomass not in the reaction chamber or the TS content  or decrease little. The clear water can do so be fed that there is a vortex Water / sludge is coming into the clarifier. This can be done for example by increasing the circulation amount of water also reach or support. The loading of the reaction chamber in the further can be advantageous with a high biomass fraction respectively.
• - An alternative and / or cumulative measure exists in the small sewage treatment plant with a float switch Determination of the wastewater fill level in the primary clarification chamber and / or to form a cleaning chamber. Especially at the wastewater level will decrease decline. The float switch can indicate this. about a corresponding control device can then for example, the aforementioned measures have been initiated or implemented.

Thereafter, the invention relates to its most general Embodiment a small sewage treatment plant for biological Wastewater treatment using the SBR process with a Pre-clarification chamber, a biological cleaning chamber as well Facilities for the discharge of wastewater into the primary clarification chamber, for transferring the waste water from the primary clarification chamber into the Cleaning chamber, for draining the waste water from the Cleaning chamber and for the return of sedimentation material from the reaction chamber into the primary clarification chamber and includes at least one conveyor in the primary clarifier and / or Cleaning chamber, the suction side end in its position is adjustable in a chamber and its output side Ends in the other chamber.  

According to one embodiment, the conveyor is a Airlift device. The suction end is there in particular vertically adjustable, for example by a telescopic design of the suction end. Likewise can the suction-side end can be adjusted along a rail, especially if the delivery line is flexible.

Instead of a conveyor that is adjustable on the suction side the small sewage treatment plant also has at least one Have conveyor that with at least two suction-side ends (or alternatively two Conveyors with one suction end each) the suction ends at different positions in the are arranged in each chamber and their at least one output end ends in the other chamber.

In this embodiment, several can be mobile or static Suckers arranged in different positions and - each as needed - switched on or off. This can be done, for example, using appropriate valves (flaps) happen in the delivery lines.

It is also the case here that the conveyor device in particular has a Compressed air lifting device, which has the advantage that it has no moving parts.

The change in position of the suction end of the Conveyor can by a control device be supported depending on one in one defined unit of time introduced into the primary clarification chamber  Amount of waste water the position of at least one suction end the delivery line is automatically changed or on Fluidically switched off end and at least one other Fluidically connected at the end.

If the small sewage treatment plant is equipped with the above-mentioned float switch, this can display the changed sewage inflow. An associated regulation / control unit can be programmed as follows, for example:
If the supply of new wastewater is interrupted for a certain time, this is indicated, the suction point of the conveyor of the reaction chamber is moved upwards and clear water (instead of sludge) is led out of the reaction chamber into the pre-clarification chamber. Alternatively or cumulatively, the amount of waste water returned and / or the conveying speed can be increased. Increased turbulence in the primary clarification chamber (mixing of the wastewater with the sludge) is desired, as a result of which new nutrients (biological substrate) are subsequently fed into the reaction chamber, thus ensuring at least the basic supply of the microorganisms. At the same time or at different times, the suction pipe can be lowered in the preliminary clarification in order to convey sludge (biomass) into the biological reaction chamber.

The liquid level of the primary clarification chamber can also be lowered which increases the ratio of biomass: water. The proportion transferred into the reaction chamber is then higher with Biomass concentrated.  

This cycle is maintained until again more or less normal wastewater from the sewage treatment plant be fed. The measures described lead to a higher buffer capacity. The above can Control circuit over a certain further period of time be maintained to the nutrient content in the plant overall faster to normal level. After that the system can return to normal operation.

A side effect is that by taking biomass the buffering capacity of the primary clarifier and the Period until the next sludge removal (from the primary clarification chamber) is extended.

The above measures are for example at a Gastronomy operation conceivable, in addition to rush hours on weekends produces only small amounts of waste water during the week or during vacation times. The one described Process engineering can be reversed with disproportionate Realize wastewater. Accordingly, more will be done Excess sludge led into the primary clarification (for example through Lowering the level of the proboscis in the reaction chamber). The increase in the amount of sludge in the primary clarifier creates the Possibility of later weak times through appropriate To be able to compensate for sludge.

Based on the following description of various examples are aerators to support an aerobic Biology described which also includes the mixing of the wastewater promote. The same applies to agitators that are used on an optional basis can be.  

Further features of the invention result from the features of the subclaims and the other registration documents. The features mentioned can be used individually as well as in any combinations for realizing the invention to be of importance.

As far as wastewater, clear water or mud Technically speaking, this means mixing systems with each different liquid / solid proportions accordingly the respective process level and control of the system.

The invention is based on an embodiment example explained in more detail, the only figure is a strong schematic sectional drawing through an inventive Small sewage treatment plant shows.

The system essentially consists of a pre-clarification chamber 10 and a biological reaction chamber 12 .

Waste water enters the primary clarification chamber 10 via an inlet 10 z and can sediment there (sludge area 10 s). A compressed air lifting unit 20 is used to transfer waste water and / or sludge from the primary clarification chamber into the cleaning chamber 12 . The compressed air lifting system 20 is described below with reference to the identical system 16 . With it, wastewater and / or a sludge / wastewater mixture depending on the arrangement of the suction end 20 s and the mixing in the chamber 10 can be conveyed. Aerators 14 ensure intensive aerobic mixing of the waste water.

After a defined treatment time, the ventilation is switched off. As a result, sludge 12 s settles on the bottom of the biological cleaning chamber 12 . During this treatment phase in the reaction chamber 12 , the inflow of waste water from the pre-clarification chamber 10 is interrupted. After a defined rest period (sedimentation time) in the reaction chamber 12 , clear water is withdrawn from the reaction chamber 12 via an outlet 12 a (which may include a conveying device).

In the reaction chamber 12 is an airlift device 16 is arranged with its suction-side end s sixteenth The discharge end 1% opens into the pre-clarification chamber 10 . A compressed air line 16 d opens into the main pipe 16 h approximately midway between the ends 16 s, 16 a. If compressed air is supplied via line 16 d, a vacuum is formed at the suction end 16 s of the main line 16 h.

When the sludge level in the reaction chamber 12 has approximately reached the level 12 v, so-called excess sludge is conveyed from the reaction chamber 12 into the primary clarification chamber 10 .

This sludge flow is interrupted as soon as the sludge level drops below 12v or the compressed air supply via line 16d is interrupted.

The lower end 16 u of the main line 16 h (below the feed point of the pressure line 16 d) is telescopic, so that the distance between the suction end 16 s and the bottom 12 b of the reaction chamber 12 can be changed. It can also be used to set from / up to which sludge level (variable sludge level) 12 v excess sludge is transferred to the primary clarification chamber.

The relevant tasks and functions and the associated control devices have already been described above. This includes raising the position of the suckers 16 s, i.e. increasing 12v, in order to lead clear water 12 k (above 12s) into the primary clarification chamber.

A float 18 is indicated only schematically along a wastewater level, designated 22, in the primary clarification chamber 10 , the function of which has already been explained and is connected to an evaluation unit 24 via which the functions described can be controlled.

Claims (12)

1. Small sewage treatment plant for biological wastewater treatment using the SBR process, with a pre-clarification chamber ( 10 ), a bio-logical cleaning chamber ( 12 ) and devices ( 10 z, 20 , 12 a, 16 ) for introducing wastewater into the pre-clarification chamber ( 10 ), for transfer of the effluent from the pretreatment chamber (10) in the cleaning chamber (12) for discharging the waste water from the cleaning chamber (12) and for returning Sedimentationsgut from the reaction chamber (12) into the pretreatment chamber (10), characterized by at least one conveyor ( 16 , 20 ), the suction-side end ( 16 s) of which is adjustable in its position in one of the chambers ( 10 , 12 ) and whose outlet-side end ( 16 a) opens into the other chamber ( 12 , 10 ). 2. Small sewage treatment plant according to claim 1, wherein the suction end ( 16 s, 20 s) of the conveyor ( 16 , 20 ) is vertically adjustable. 3. Small sewage treatment plant according to claim 1, wherein the suction end ( 16 s, 20 s) of the conveyor ( 16 , 20 ) is telescopically adjustable. 4. Small sewage treatment plant according to claim 1, wherein the suction end ( 16 s, 20 s) of the conveyor ( 16 , 20 ) is adjustable along a mounting rail. 5. Small wastewater treatment plant for biological wastewater treatment using the SBR process, with a pre-clarification chamber ( 10 ), a biological cleaning chamber ( 12 ) and devices ( 10 z, 20 , 12 a, 16 ) for introducing wastewater into the pre-clarification chamber ( 10 ) reconciliation of the effluent from the pretreatment chamber (10) in the cleaning chamber (12) for discharging the waste water from the cleaning chamber (12) and for returning Sedimentationsgut from the reaction chamber (12) into the pretreatment chamber (10), characterized by at least one conveying direction, whose at least two suction-side ends are arranged at different positions in one of the chambers and whose at least one output-side end opens into the other chamber. 6. Small sewage treatment plant according to claim 5, in which the suction side Ends of the at least one conveyor vertically are spaced.   7. Small sewage treatment plant according to one of claims 1 to 6 with a control device ( 24 ), the position of at least one suction-side end ( 16 s, 20 s) of the conveying device (depending on a quantity of waste water introduced into the pre-clarification chamber ( 10 ) in a defined time unit) 16 , 20 ) changed. 8. Small sewage treatment plant according to one of claims 5 to 7 with a control device ( 24 ), which switches off at least one suction-side end of the conveying device in terms of flow technology and at least one other suction-side end in terms of flow technology, depending on a quantity of wastewater introduced into the pre-clarification chamber ( 10 ) in a defined time unit , 9. Small sewage treatment plant according to one of claims 1 to 8 with a float switch ( 18 ) for determining the wastewater fill level. 10. Small wastewater treatment plant according to claim 9 with a control device ( 24 ) which, depending on the wastewater fill level determined by the float switch ( 18 ), regulates a quantity of wastewater and / or sedimentation material led from the pre-clarification chamber to the reaction chamber. 11. Small sewage treatment plant according to one of claims 1 to 12, in which the conveying device ( 16 ) is a compressed air lifting device. 12. Small sewage treatment plant according to one of claims 1 to 12, in which the conveyor comprises a mammoth pump.