DE19520564C1 - Effluent or water denitrification process and appts. - Google Patents

Abstract

Process for the denitrification of water comprises rotating immersed bodies into which the water is cascaded through reactor elements and then biologically reduced. Depending on a contamination equiv., obtd. by multiplying the flow vol. of the incoming water with the redox potential measured from the redox potential difference between the inlet and outlet regions, various sizes of microorganism material fixed onto spherical carrier material are kept under reducing conditions in a reactor region. The reactor region comprises a sloping drum resembling a rising screw conveyor. The dwell time of the water is varied by changing the water level. Also claimed are: (1) an appts. for carrying out above process, and (2) an effluent treatment plant using this process and appts.

Description

The invention relates to a method and a device for denitrification of water in general and for the denitrification of waste water with a be knew preliminary and post-treatment and biological wastewater treatment Rotary immersion bodies made of ge filled with spherical carrier material inclined drum.

Rotating immersion bodies consisting of vertical disks or are known Rollers that are arranged on a horizontal shaft and in a partial Immerse the container filled with waste water and through which the waste water flows. The disks are disks or rollers composed of sections non-rotatably attached to the shaft (DE 05 31 40 372). The wave is about at the level of the water, so that the rotation on the Schei microorganisms located alternately with the water and the environment come into contact with ambient air.

The performance of these systems is significantly different from that of the microorganisms populated surface dependent. The known devices have in Ab stood from about 1 cm on the shaft held plastic discs of about 1-2 cm Thickness with a diameter of 2 to 3 m. The disc diameter and the Thickness is for structural reasons - and therefore also the maximum surface che - limited. The distance between the panes must not fall below a minimum value so that the gaps do not become overgrown by the microorganisms (Windscreen wipers have not proven themselves otherwise). Furthermore, the Execute panes with the lowest possible weight in order to reduce the amount of material and to keep drive energy low. The manufacture of the disks from ge foamed plastic in one body requires large and expensive tools. Such discs are very light, but on the other hand sensitive to me chanic influences. Disks composed of segments are hand licher. But you need additional assembly effort and holding frame. Several discs or honeycombs are combined into packages and are from  a common shaft (DE AS 28 06 415) or one shaft each (DE PS 35 02 762) worn.

To enlarge the surface and reduce the manufacturing effort known various suggestions. According to DE PS 31 40 372 the circumferential disc spaces are covered to close reaction chambers create. According to DE 05 35 32 948, plastic pipes are axially parallel and in DE PS 35 13 602 attached spirally on the shaft.

With rotating immersion body systems it has been shown in the past that the uneven shaft loads caused by different growths of the Microorganisms on the offered surfaces to fail the equipment have leads. Furthermore, sludge deposits lead to anaerobic zones in the Containers which on the one hand result in acidification of the waste water and a temporarily increased COD in the process as well as on the other bestial scent produce.

However, the immersion bodies are also characterized by a low energy requirement and relatively good mining performance. The effective one, from the ambient air Originating oxygen input is so large that a widespread in wastewater plants nitrification becomes possible. Degradation of the nitrates by a Denitrifika tion is not without due to the aerobic conditions in these plants further (for example installation of a submerged, only stirred reaction space) possible.

In order to save an additional process step, DE GM 78 19 138 was proposed beaten, the waste water level after nitrification temporarily up to the upper the edge of the panes, the system being sealed in the upper area becomes. This measure is intended to create anaerobic conditions, to cause denitrification. However, the system works dis continuously and requires additional construction work.

BIO-NET immersion bodies from NSW Umwelttechnik, Nordenham (company prospectus) can also be denitrifying in continuous flow be stowed by the immersion cascade steps and with an external a return flow can be operated via pumps.

The invention is based on the object of creating a system which is generally suitable for the denitrification of water, in wastewater treatment plants but also the biodegradation of the carbon compounds more effective and safe and easy control of the system on Denitrifika tion for nitrogen elimination. Another task is va riable design of a wastewater treatment plant for various mining companies different wastewater compositions and extensive Sludge reduction by changing aerobic and anaerobic environment.

The task of denitrification is solved in that one with spherical loosely filled drum with perforated jacket on a ge inclined shaft is used as a reducing reaction space. In connection with guide vanes and stabilizing the strength of the shaft and drum The water to be denitrified becomes segments of flat fixed bed material transported in cascade. The dwell time of the water in a kaska de depends on the water level, which has a redox potential difference  mood between a nitrate-containing and low-nitrate measuring point in Verbin tion is controlled with the inflow as a pollution equivalent.

One or more drums can be used in the different versions one above the other or several inclined shafts with drums in parallel or are used in series. If larger units and thereby several drum units are required can be inventively by means of controllable individual drives, the shafts in different rotations intensity operated and different metabolic pathways to carbon and Nitrogen elimination - anaerobic / aerobic - can be optimized.

The shaft on which the drums are attached is according to the invention inclined. In the drums there are drivers, on the one hand the what promote, on the other hand, take the carrier materials with you and in their mutual situation constantly change to form braids and ver to prevent sludge.

The reaction spaces are segmented by means of height-adjustable overflows in accordance with a pollution equivalent factor according to the invention different reaction volumes for denitrification, but also nitrification create. When the water level is low, the carrier materials emerge from the Water and take up oxygen from the air to the organic water oxidize ingredients.

Finally, according to the invention, conveyor bars are placed around the body, the What water and mud from the area between the drum and the jacket sole to the Promote the head of the shaft so that depending on the water level the mud-water Mixture can be added to an overflow in a phase separator.

A sludge collecting space is provided in the swamp area of each wave according to the current pollution equivalent sludge from in the Plant built-in phase separators is given to over mud breathing to increase the degree of denitrification and to oxidize the sludge itself to let.

Finally, according to the invention, one or more waves can temporarily over not moved at all or operated in the opposite direction of rotation, to let mud get into the swamp.

According to the invention can also circulate through openings or weirs Ser streams for the supply of nitrified water into which denitrifying the reaction rooms are set up.

The reaction spaces and dwell times controlled via the water level the controlled inflow of nitrate-containing water and the different Rotational movements and intensities as well as possible different tears Germ materials in the drums differentiated biologically active reactors create optimal conditions for the microorganisms and thus high degradation effects under different loads.

With the formation of single or several inclined drums It is easy to adapt to the required degree of cleaning.  

The proposed procedure is particularly advantageous when the water is in the Must be promoted because the pump energy is already being used, to carry out the required metabolism at the same time.

The invention is explained below using an exemplary embodiment.

Fig. 1 shows two drums ( 2 , 3 ) in a spatial representation, partially cut open.

In the exemplary embodiment, the two drums are arranged on a shaft ( 1 ), but separated by a partition with an adjustable weir ( 7 ), so that two different reaction spaces are created. The fill level in the second reaction chamber is changed by the weir ( 8 ), the lowest possible fill level reflecting a system for carbon and nitrogen oxidation. The water level positions are set via the redox potential difference at the measuring points 10 and 11 via the described path of the pollution equivalent. In the case of very small systems, the potential difference between the oxidized and reduced state of the water is determined; in the case of several drums in a row, the denitrification is recorded directly via the state between nitrate-containing and nitrate-free water.

A drive ( 5 ) is attached to the front wall, which drives the drum ( 2 ) and, via the common shaft ( 1 ), also drives the drum ( 3 ). Conveyor strips ( 6 ) are attached to the drums; loose carrier materials ( 9 ) are filled into the drums, which can also differ in structure from drum to drum. In the drums (not visible), drivers or guide vanes are attached in the same way as the screw lift to transport the water forward.

The tub is tightly formed on the drum for effective response to have space in the drum. The drums are made of mesh material, so that water flows around the substrate.

A heater is arranged on the reactor trough 12 . The entire container is provided with thermal insulation on the outer wall to maintain heat. The measuring and control system and the energy supply for regulating the speed and level as well as the inflow and outflow quantities are arranged separately. Due to the different level heights, the separated sludge can flow back into the bottom of the denitrifying drum (s).

Reference list

1 wave
2 drums (preferably only for denitrification)
3 drum (suitable for nitrification)
4 toothed belts for power transmission
5 drive motor (forward, reverse, variable speed)
6 (symbolized) conveyor bars
7 , 8 overflow weir threshold
9 spherical carrier material
10 , 11 measuring point
12 reactor trough.

Using the example of a wastewater treatment plant in Fig. 2, it is explained how the plant works: from a possible preliminary treatment, the raw wastewater is fed into the reducing reaction chamber, mixed with nitrate-containing water from the outlet of the plant in accordance with the explained pollution equivalent factor and in accordance with a weir be treated at the end of the wave and promoted moderately. Behind the weir of the inclined arranged Rota tion compression body 1 there is a phase separator from the slurry can be added to the bottom of the rotation immersion body 1 intermittently via a slide. The denitrified wastewater enters a similar, with kugeli gem carrier material or from flat elements Rota tion diving body 11 , where it is nitrified and the carbon is completely oxidized. The biologically treated water is freed of solids via a variable overflow threshold, which is also provided for setting the dwell time, and partially added to the feed to reduce the nitrate.

With a low wastewater inflow, the plant runs in a circle and denitrifies all nitrate; in the case of a high inflow, rotary immersion bodies 1 are also used partially nitrifying. Three redox potential measurements are used in this system: in the area of mixing the inlet and nitrate-containing water in the rotary immersion body 1 , in the outlet area of the rotary immersion body 1 and in the outlet of the rotary immersion body 11 .

Claims (12)

1. A process for the denitrification of water with rotating immersion bodies, in which the water is cascaded through reactor elements and thereby biologically reduced, characterized in that, depending on the inflow volume flow and reduction potential, measured via the redox potential difference in the inlet and outlet area by multiplication to the pollution equivalent a differently sized microorganism mass fixed on a spherical carrier material is held in a slanted drum configured as a screw jack, as a reaction space under reducing conditions and the dwell time of the water is varied by changing the water level. 2. The method according to claim 1, characterized in that the speed the shaft and / or water level carrying the drum or drums height of the reaction chamber depending on the pollution equiva lent is controlled. 3. The method according to claim 1 and 2, characterized in that the zu Leading nitrified water into the reaction chamber for denitrification tion is controlled depending on the pollution equivalent. 4. The method according to claims 1 to 3, characterized in that depend gig of the level of the pollution equivalent of excess sludge in the denitrifying effective reaction space and an autoxi dation of the sludge is introduced. 5. The method according to claims 1 to 4, characterized in that the or partly through the denitrifying reaction spaces Lowering the water level can be operated oxidizing.   6. Device for performing the method with cascade arranged, cylindrical rotating immersion bodies, which with spherical gene carrier materials are filled, characterized in that the Shaft on which one or more drums are mounted is inclined and provide the drums with water-promoting guide vanes Partitions partitioned, surrounded by a perforated jacket, with spherical carrier materials are loosely filled and that they are in for the denitrification intended reaction space at the lower En de are always submerged in the wave. 7. The device according to claim 6, characterized in that in the spherical carrier materials filled, cylindrical body entrainment mer for a continuous change of position of the carrier are installed. 8. Apparatus according to claim 6 and 7, characterized in that the drums are meandering, the mud from which the Can clean the surrounding jacket sole, scooping for Water and mud act and water and mud from the reacti onsraum an overflow. 9. Device according to claims 6 to 8, characterized in that if there are several drums on a shaft between the drums adjustable tooth sills for different immersion depths Drums are arranged. 10. Device according to claims 6 to 9, characterized in that the overflow at the top of the shaft is designed as a sedimentation vessel and the water phase is subjected to a further treatment, while the sedimented sludge phase via a slide in phases with low loading load according to the pollution equivalent parameter or by time timer controlled is fed to the sump of the system. 11. The device according to claims 6 to 10, characterized in that the shaft temporarily does not move at all or in a different direction of rotation operated and sludge automatically or supported by the other Rotary motion fed to the swamp. 12. Wastewater treatment plant according to the above claims, because characterized in that Trom designed according to the same principle mel (n) on a horizontal shaft for nitrification of waste water sets and is combined with the device according to claims 6 to 11 that controlled by the pollution equivalent, part of the cleaned, but nitrate-containing water in the feed to the denitrification stream melreaktor given and by raw wastewater or supplied sludge is reduced.