WO2017037168A1

WO2017037168A1 - Apparatus for biological liquid purification with a loop reactor

Info

Publication number: WO2017037168A1
Application number: PCT/EP2016/070606
Authority: WO
Inventors: Holger Thielert; Jörg TARON; Kerstin STENZEL
Original assignee: Thyssenkrupp Industrial Solutions Ag; Thyssenkrupp Ag
Priority date: 2015-09-04
Filing date: 2016-09-01
Publication date: 2017-03-09
Also published as: CN108025936A; CN108025936B; DE102015114888A1

Abstract

The invention relates to an apparatus for biological liquid purification by addition of a gas, with a reactor vessel (1) for receiving liquid (2), which reactor vessel (1) has a gassing zone (3) at a lower portion of the vessel and a reaction zone (4) at an upper portion of the vessel, a liquid inlet, a liquid outlet (12), a gas inlet opening into the gassing zone (3), a pipe (8) which extends vertically in the reaction zone (4) and by which flows of fluid on its outer face on the one hand and on its inner face on the other hand are separated from each other, wherein the reaction zone (4) has a fluid contact area (10) above an upper end of the pipe (8). According to the invention, several modules (5), each of them with a pipe (8) and with a gas inlet, are arranged in the reactor vessel (1).

Description

ANNEX TO BIOLOGICAL LIQUID CLEANING WITH ONE

SCHLAUFENREAKTO

description

TECHNICAL AREA

The invention relates to a plant for biological fluid purification with the addition of a gas with a reactor vessel for receiving liquid, which has a reaction zone at a lower tank portion and a reaction zone at an upper tank portion, a liquid inlet, a liquid outlet, a gas feed opening in the mass transfer zone and a In the reaction zone in the vertical direction extending tube, which is intended to separate on the outside on the one hand and its inner side on the other hand opposite fluid flows from each other, wherein the reaction zone above a top end of the tube has a fluid calming.

BACKGROUND

The plant is preferably a reactor intended for wastewater purification using bacteria. The plant can also be referred to as a bioreactor or detoxification reactor.

With regard to the basic operation and structure of the plant, the present invention relates in particular to a configuration referred to as a jet zone loop reactor (SZR reactor).

The plant according to the invention in the form of a bioreactor is provided in practice for a reaction and thus for a degradation of various pollutants. The bioreactor, for example, work with bacteria that need to be supplied with oxygen, including the liquid to be purified, especially wastewater, must be mixed as well as possible with air or other oxygen-containing gas.

A generic system is known from DE 198 42 332 AI. The plant for biological wastewater treatment has a mass transport zone for Introducing a gaseous oxidizing agent, in particular air, into the liquid to be purified. A particularly intimate mixing of gas and liquid can be achieved by a turbulent loop flow, wherein a two-fluid nozzle, the liquid to be purified, including bacteria and the gas are supplied. The fluids are guided so that a turbulent flow results, which causes an intimate mixing.

The mixture of air, polluted waste water and the bacteria present in the reactor rises after intimate mixing on the outside of a vertically extending tube in a reaction zone upwards. When this mixture reaches the surface, the gas (e.g., air) contained in the mixture in the form of small bubbles is at least partially released, thereby increasing the density of the mixture. The mixture having a greater density after the delivery of gas can then sink downwards again in the direction of the two-substance nozzle through the inner cross-section of the tube, resulting in the one circulating flow. The circulating flow is also referred to as loop flow. Due to the arrangement and function of the tubes, the terms plug-in tube and loop tube are also common in the art.

The system is preferably designed so that the residence time of the liquid to be purified in the mass transport zone is relatively short, while then the intimately mixed with gas / air mixture rises over a longer period in the reaction zone upwards, whereby during the rise of the mixture of biological Degradation of pollutants by bacteria takes place.

A generic system can not only for the purification of municipal wastewater, but with a suitable process control for biological treatment of highly polluted industrial wastewater, eg. As coke oven wastewater are used, which is charged, inter alia, with nitrogen compounds, cyanides, phenols and sulfides. A corresponding method is known from WO 2012/139917 A2. Because of their high concentration of toxic ingredients that inhibit nitrification, coking plant effluents are among the most problematic industrial wastewaters. Treatment with conventional biological processes requires low-load and therefore large-volume concrete-basin bioreactors. Sensitive biological processes such as nitrification are always endangered by impact with critical substances such as cyanide and phenol. By separating the treatment into a first and a second biological stage, sensitive, slow-growing autotrophic bacteria are protected from damage by cyanide, phenol and other foreign substances. The first biological stage is used for detoxification, there inhibitors of nitrification, such as. As cyanides degraded. This is followed by a membrane filtration, which separates the bacteria of the first stage from those of the second stage, so that different types of bacteria can form. In the second stage, the nitrogen decomposition takes place by means of nitrification, denitrification and post-aeration.

Known SZR bioreactors have a circular cylindrical housing, which is usually made of steel. Due to the above-described mode of operation of SZR bioreactors, strict technical boundary conditions must be taken into consideration when designing for a specific throughput volume, because a specified range for the ratio between the diameter and the height of the housing must be observed. For large throughput quantities, therefore, correspondingly large reactor heights result, wherein alternatively a plurality of individual SZR bioreactors can be arranged separately from one another.

DESCRIPTION OF THE INVENTION

Against this background, the present invention has the object to enable a compact design of a plant for biological fluid purification with the addition of a gas, during the design and a flexible adaptation to different throughputs and the available space to be made possible. The object of the invention and solution of the problem is a system according to claim 1.

Starting from a generic system with the features described above, it is accordingly provided according to the invention that a plurality of modules each having a tube, a two-fluid nozzle and a gas supply are arranged in the reactor vessel. The individual modules can be designed in terms of their dimensions so that there is an optimal operation. In the context of the invention several modules are provided side by side, which are arranged together in a reactor vessel, so that there is a particularly efficient design compared to a plurality of individual, separate bioreactors. The juxtaposed modules form a bundle of reactor spaces.

Preferably, the in modules in the mass transport zone and in the reaction zone at the height of the tubes are separated by partitions, wherein the reactor vessel in the fluid calming above the partitions forms a common for all modules accumulation section, to which the liquid outlet is connected. The separated by the partitions modules (in only two modules, a single partition may be sufficient) do not differ in their function from the known from the prior art systems for biological fluid purification with the addition of a gas. However, the modules share a common reactor vessel, wherein the partition walls only have to prevent overflow of the liquid in the lower region of the reactor vessel and can be made correspondingly thin. Depending on the configuration, it is also possible to provide simple sheets as partitions.

According to the described preferred embodiment, the modules are open at the top, wherein the fluid calming area above the partitions a forms a common accumulation section for all modules. Above the partitions, therefore, the ascended liquid can flow freely and be divided as needed into different fluid streams. Usually, the amount of purified liquid is continuously discharged via the liquid effluent, which corresponds to the amount of waste water supplied by the liquid feed.

As described above, a large part of the liquid will again sink from the fluid calming region through the tubes of the modules and thus be recirculated.

In order to achieve a particularly intimate mixture in the mass transfer zone, however, it is additionally expedient if liquid is withdrawn from the fluid settling region and then fed together with the gas under pressure to a two-substance nozzle which opens into the mass transfer zone and there the mixture downwards and to Side so that the mixture can rise in the manner described on the outside of the tubes to the top.

According to a preferred embodiment of the invention, starting from the fluid calming region, there are thus three flow components, namely the sinking of the liquid in the tubes, the withdrawal of the liquid in order to be supplied together with the gas under pressure to a two-substance nozzle and the discharge of purified liquid through the liquid drain.

In the context of the invention, the discharged portion as well as the portion, which is supplied to the two-fluid nozzle, either removed together and then separated or removed from the outset via separate ways, the latter embodiment is preferred.

Although the modules are arranged in a common reactor vessel, the partitions also allow operation of only a portion of the modules. For maintenance or low fluid flow temporarily individual modules can be deactivated. The gas supply lines and optionally also the supply lines for the liquid-bacteria mixture supplied to the two-substance nozzle are then shut off with suitable valves, wherein for a flexible process control preferably control valves, control valves and / or adjustable pumps can be used, which are connected to a central process control ,

The modules can be arranged in different ways within the scope of the invention. For example, two or more modules may be arranged side by side along a straight line. A particularly space-saving and efficient arrangement results in a dense and substantially symmetrical packing of the modules.

Against this background, it is provided according to a preferred embodiment of the invention that the modules bounded by the partitions and possibly also an outer wall of the reactor vessel in a horizontal section each have the shape of a uniform polygon. For example, the modules may have a symmetrical hexagonal shape, with six modules forming a ring, for example. In the middle of such a ring then remains a surface with the same cross section, so that there either a further module or a central overflow channel can be arranged. The formation of a central overflow channel is of course also possible if more or less than six modules are joined together in a uniform arrangement to form a ring.

The central overflow channel can be provided both as a liquid outlet for the purified liquid to be discharged and for a circulation stream of the liquid which is fed to the two-substance nozzle.

Regardless of the concretely selected design, for example, between three and twelve modules can be arranged in the reactor vessel. According to a preferred embodiment of the invention is further provided that the gas supply lines are each guided from above through the associated tube of the corresponding module, which can be dispensed with lateral connections in the reactor vessel. The gas feeds can then be designed in the manner of lances.

If - as described above - the gas feeds of the modules in the mass transfer zone open into two-fluid nozzles, which in addition to the gas to be purified liquid including bacteria is supplied, corresponding lances can also have separate cross-sections for the liquid to be cleaned or circulated and the gas ,

According to a preferred embodiment of the invention, the reactor vessel is at least partially formed of concrete, both the outer wall and the partitions can be made of concrete, with concrete compared to steel in the construction of the system is often locally available and relatively cheap. At the manufacture of the reactor vessel at least partially made of concrete, no high demands are made, so that suitable structures can be formed by simple formwork.

In particular, if the reactor vessel is at least partially formed of concrete, the above-described supply of the gas and the optionally circulated liquid via lances from above is advantageous, because then at least at the bottom of no or at least a few connections are provided in the reactor vessel must, which can be associated with a design of concrete with a considerable effort and leads to potential weaknesses.

In the operation of the system preferably various pollutants are converted by bacteria. For example, cyanide and hydrocarbon components can be converted in a first stage to ammonium ions (NH ₄ ⁺ ). In a second stage, the ammonium ions formed as well as already contained in the wastewater at the beginning Ammonium ions converted to nitrate (NO ₃ ). In principle, however, other biological and / or chemical reactions can be provided in the system.

The fact that several modules are used according to the invention not only saves space and in particular limits the height necessary for the installation. Furthermore, in comparison with a number of separate plants, a simplification with respect to the ramming is also possible, wherein previously described, a central overflow channel can be provided in the case of an annular arrangement of the modules. In addition, the supply and discharge lines can also be branched relatively short. Furthermore, all modules can also be operated with common pumps, compressors or the like.

According to a further aspect, which has an independent inventive significance and which also leads to a further improvement in the known systems of the prior art, a compensation chamber is connected to the reactor vessel via a fluid connection, wherein the fluid connection is arranged above the liquid outlet and wherein the compensation chamber above the Fluid connection has a permeate and a permeate. In the compensation chamber, for example, the permeate (filtrate) of a membrane filtration can be collected, which is downstream of the purification of the wastewater in the system according to the invention. For example, it may be an ultrafiltration.

Through the compensation chamber, the control engineering effort to regulate the level in the system and for the regulation of excess permeate can be greatly reduced. In combination with a bioreactor, membrane filtrations for bacterial retention can be used in biological wastewater treatment. However, the throughput of a membrane filtration can not be controlled arbitrarily, as always a certain overflow velocity is required so that the membranes do not block. With process fluctuations, it can happen that Filtration with the Mindestströmströmgeschwindigkeit too much permeate is obtained. If the over-produced permeate is then forwarded completely to the next process step, there is no continuous overflow in the upstream system in the form of the bioreactor. The downstream process step would be supplied with too much water, which would lead to a full or overflow. In addition, a fluctuating reactor overflow can lead to a failure of the filtration system, because then under certain circumstances, the Mindestüberströmgeschwindigkeit is no longer guaranteed.

Characterized in that according to the further aspect of the present invention, the compensation chamber is connected via a fluid connection to the reactor vessel, the levels in the reactor vessel and the Permeatsammelkammer on. Thus, the level in the reactor can not fall. There is thus a uniform overflow, and not too much water is transferred to the next process step. A backflow of permeate into the reactor vessel can be accepted.

The permeate feed and the permeate effluent are arranged on the compensation chamber in such a way that an inflow of unpurified liquid into the compensation chamber and into the permeate discharge is avoided.

DESCRIPTION OF THE FIGURES

The invention will be explained in the following with reference to a drawing showing only one exemplary embodiment. Show it:

1 shows a plant according to the invention for biological fluid purification with the addition of a gas in a vertical section,

2 shows the system according to FIG. 1 in a horizontal section,

3 shows an alternative embodiment of the system according to the invention in a vertical section, 4 shows the system according to FIG. 1 in a horizontal section along the line AA of FIG. 3.

DETAILED DESCRIPTION OF THE FIGURES

1 and 2 show a first embodiment of a plant according to the invention in the form of a bioreactor for biological wastewater treatment with the addition of a gas, in particular air. Due to the functionality of the plant is also referred to as SZR bioreactor (jet zone loop reactor), because - as explained in detail below - in the system a loop-shaped circulating flow is generated.

The plant has a reactor vessel 1 for receiving liquid 2, wherein a mass transfer zone 3 is provided at a lower vessel section and a reaction zone 4 is provided at an upper vessel section.

From a comparative examination of Figures 1 and 2 it can be seen that within the reactor vessel 1, three modules 5 are provided with matching structure, each module 5 has an air and water supply line 6 in the form of a lance, which opens into a two-fluid nozzle 7.

The combined air and water supply line 6 is guided by a tube 8, the insertion tube, which extends in the vertical direction in the reaction zone 4 and is intended to separate opposite fluid flows from one another on the outside and on the inside.

Below the two-fluid nozzle 7, each module 5 has a short mixing tube 9 in the mass transport zone 3. In addition to compressed air through the air and water pipe 6 promoted liquid may be newly added, to be cleaned wastewater, circulated wastewater or preferably a mixture of the two components. The air and the waste water are discharged at the two-fluid nozzle 7 under pressure, so that there is a turbulent flow, wherein the Mixing tube 9 in the mass transport zone 3, a first circulating flow can be generated before the air-water mixture rises due to its lower density on the outside of the associated tube 8 upwards, wherein provided in the reactor vessel 1 bacteria can degrade pollutants such as cyanides and phenols.

The air-water mixture rises to a fluid calming area 10 on the fluid surface, where the air bubbles contained in the air and water mixture can be released there to some extent, so that the density of the mixture increases again and the only smaller amounts of air containing wastewater to a proportion through the interior of the tubes 8 may again fall in the direction of the two-fluid nozzle 7, whereby also in the reaction zone 4, an annular (loop-shaped) flow is generated.

From Fig. 1 it can be seen that the modules 5 are separated in the mass transport zone 3 and in the reaction zone 4 at the height of the tubes 8 of partitions 1 1, wherein the reactor vessel 1 in the fluid calming region 10 above the partitions 1 1 one for all Module 5 forms a common accumulation section, to which a plurality of liquid drains 13 are connected, of which the at least to some extent purified wastewater is fed to a subsequent process step.

Below the liquid drains 13, according to FIG. 1, further fluid connections 12 are provided around the periphery, at which wastewater is withdrawn from the reactor vessel and added to the air and water supply lines 6 under pressure. A pump provided for the promotion is not shown for reasons of clarity.

In the context of the invention there is the advantage that for the individual modules 5, an optimal ratio of diameter and height can be adjusted, while the design effort and in particular the overall height of the system remain relatively low. It is further apparent from FIG. 2 that a compensating cannister 15 is connected to the reactor vessel 1 via a fluid connection 14, wherein the fluid connection 14 is arranged above the fluid connections 12. The compensating cannister 15 further includes a permeate feed 16 and a permeate effluent 17. The compensating cannister 15 is designed to receive excess permeate from a membrane separation unit, not shown, and optionally to pass it back into the reactor vessel 1. This results in simplifications in terms of process management, because for the operation of a membrane separation plant often certain flow rates must not be exceeded, in order to avoid blocking of the membranes. If an operating condition results in which too little wastewater is supplied to the reactor vessel 1, then liquid can be circulated through the equalization chamber 15 between the reactor vessel 1 and a downstream membrane separation plant in order to ensure the necessary minimum throughput.

In the context of the invention, the reactor vessel 1 and the partitions 1 1 can be made of concrete, resulting in particularly low production costs. In particular, it should also be considered that concrete is often locally available and the reactor vessel 1 and the partitions 1 1 can be formed by simple formwork.

The air and water supply lines 6 are inserted from above into the modules 5, so that a particularly easy maintenance is possible. As a result of the construction of a plurality of modules 5, which are separate in the lower region of the reactor vessel 1, the system can also be operated only with a part of the modules 5, for example if individual modules 5 are deactivated or have to be maintained at low throughput quantities.

The limited by an outer wall of the reactor vessel 1 and the partitions 1 1 modules 5 have in a horizontal section the shape of a uniform polygon, namely a hexagonal shape, so that results in a geometrically simple structure.

Fig. 3 shows an alternative embodiment of the plant for biological fluid purification with the addition of a gas, wherein the modules 5 are not arranged as in the embodiment of FIGS. 1 and 2 in a row, but annularly as a bundle. The individual modules 5 have a hexagonal shape and form a ring, wherein in the middle of the ring an overflow channel 18 is provided, which is provided in comparison to the embodiment of Figs. 1 and 2 instead of the fluid connections 13 for the promotion of waste water in a cycle , The described arrangement of the modules 5 results in a particularly compact, space-saving arrangement, wherein the basic operation of the individual modules does not differ from the embodiment according to FIGS. 1 and 2.

The system according to FIGS. 3 and 4 is equipped with the compensation chamber 15 described above.

Claims

claims

1 . Plant for biological fluid purification with the addition of a gas with a reactor vessel (1) for receiving liquid (2) having a mass transport zone (3) at a lower vessel section and a reaction zone (4) at an upper vessel section, a liquid feed, a liquid effluent ( 12), in the mass transfer zone (3) opening gas supply, in the reaction zone (4) in the vertical direction extending tube (8), which is intended to separate on its outer side on the one hand and its inner side opposite fluid flows from each other in that the reaction zone (4) has a fluid calming region (10) above an upper end of the tube (8), characterized in that a plurality of modules (5) each having a tube (8) and a gas feed are arranged in the reactor container (1).

2. Plant according to claim 1, characterized in that the modules (5) in the mass transfer zone (3) and in the reaction zone (4) at the height of the tubes (8) of partitions (1 1) are separated, wherein the reactor vessel ( 1) in the Fluidberuhigungsbereich (10) above the partitions (1 1) for all modules (5) common accumulation section, to which the liquid outlet (12) is connected.

3. Plant according to claim 1 or 2, characterized in that in the reactor vessel between (1) three and twelve modules (5) or more modules are arranged.

4. Installation according to one of claims 1 to 3, characterized in that the modules (5) are arranged in a ring around a central overflow channel (18).

5. Plant according to one of claims 1 to 4, characterized in that the of the partitions (1 1) and optionally also an outer wall of the reactor vessel (1) limited modules in a horizontal section respectively have the shape of a uniform polygon, in particular a hexagonal shape.

6. Installation according to one of claims 1 to 5, characterized in that the gas supply lines are each guided from above through the associated pipe (8).

7. Installation according to one of claims 1 to 6, characterized in that the gas supply of the modules (5) in the mass transfer zone (3) in two-fluid nozzles (7) open, which in addition to the gas and the liquid to be purified including bacteria can be fed.

8. Plant according to claim 6 or 7, characterized in that the modules (5) each have a lance inserted from above, through which the liquid to be purified including bacteria and the gas are fed separately from each other.

9. Plant according to one of claims 1 to 8, characterized in that the reactor vessel (1) is at least partially made of concrete.

10. Installation according to one of claims 1 to 9, characterized in that the reactor vessel (1) via a fluid connection (14) a compensation chamber (15) is connected, wherein the fluid connection (14) preferably above the liquid outlet (12) is arranged and wherein the compensation chamber (15) has a permeate feed (16) and a permeate discharge (17) above the fluid connection (14).