DE19524093A1 - Water treatment process and assembly combines biological, chemical and physical stages - third chemical stage partly oxidising prod. of second regeneration stage, then returned to first biological stage, for treating heavily polluted industrial effluent - Google Patents

Abstract

An assembly which treats effluent and waste water consists of a combination of biological, chemical and physical treatment stages. The novelty is that the treatment stages consist of: (a) a biological pre-treatment stage (1, 3, 5), with the pre-treated water being drained through an outlet (6) pipe to the second stage; (b) a second stage consisting of one or more absorbers (7a, 7b, 7c, 8), >= 1 of them can be regenerated, and surrendering treated water to a third stage through an outlet pipe (9); (c) a third chemical treatment stage (13, 16, 17, 18) which is linked to the absorbers (7a, 7b, 7c) to be regenerated, by means of an inlet (14a) and outlet (14b).

Description

The invention relates to a device for purifying waste water. Such Wastewater treatment also contributes in view of increasing water pollution Pollutants on the one hand and stricter limit values for the treated wastewater on the other hand, it is a significant problem. This is particularly true for cleaning highly contaminated wastewater such as B. as commercial and industrial waste water or as Landfill leachate is created.

According to the state of the art, a distinction is made between three today basic groups of cleaning processes:

• 1. mechanical and physical processes (e.g. sieving, filtering, settling, Adsorption);
• 2. chemical processes (e.g. combustion, wet oxidation, neutralization etc.),
• 3. biological processes that can be aerobic or anaerobic, and at where microorganisms are used.

Especially for the cleaning of highly polluted industrial waste water and landfill Leachate, however, is part of the systems known in the prior art a great technical effort and therefore associated with high costs.

In contrast, the invention has set itself the task of a device and a To provide methods that use biological, chemical and physical techniques with reduced effort a safe and Cost-optimized treatment of waste water, especially industrial and landfill leachate provides.

This object is achieved by a device for the purification of waste water consisting of a first stage for the biological pre-treatment of the wastewater, one  subsequent second stage on one or more adsorbers, where at least one of the adsorbers is regenerable, and a third chemical reini level for that which arises during the regeneration of the regenerable adsorber Regenerate.

With the device according to the invention in the biological cleaning stage exploited the known and favorable properties of biological processes in order to all substances that can be removed from the wastewater, e.g. B. nitrogen compounds (Ammonium etc.). Then in the second stage with the adsorbers the pollutants not recorded in the biological processes removed, so that on the approved limit values for cleaned wastewater can leave the plant. The use of at least one regenerable adsorber ensures that the pollutants captured by this adsorber are further processed in the overall system, d. H. can be destroyed. This happens in the third, the chemical Cleaning stage through which the accumulation during the regeneration of the adsorber Regenerate is directed.

In the second treatment stage, the regenerable adsorber is preferably un arranged indirectly behind the biological pre-clarification and exists in particular from an adsorber resin fixed bed filter. It is also preferred behind regenerated adsorber arranged at least one other adsorber can consist in particular of an activated carbon fixed bed filter. Through this Combination of two adsorbers can ensure that a wide Spectrum of pollutants is removed from the wastewater. Relieved in particular the upstream regenerable adsorber the downstream Activated carbon filter. This is of particular advantage since the regenerable adsorber is without Shutting down the entire system, d. H. in continuous operation, be regenerated can.

The regenerable adsorber can in particular be constructed so that it consists of min at least two layers. The first layer is preferably made of one weakly basic anion exchanger built, and the second layer consists of macroporous adsorber polymers, preferably made of cross-linked polystyrene Divenylbenzene copolymers or from acrylic acid derivatives. The materials of the first Layer are generally selected so that they remove substances in the biological stage were not degraded, such as B. humic acids. In contrast, lower the materials of the second layer preferably the COD content (COD = chemical Oxygen requirement), which considerably relieves the subsequent adsorber stage  can be. Provided that this subsequent stage is the activated carbon filter acts, the service life is increased significantly and activated carbon to a significant extent saved. In extreme cases, the activated carbon filter can even be dispensed with entirely. The lowering of the COD content through the second adsorbent layer is particularly evident which is achieved by the following parameters: average pore diameter = 10 nm, pores volume = 0.3 to 0.4 cm³ / g, inner surface = 700 to 1,500 m² / g.

The adsorber container and the adsorber bed are in particular square or cylindrical drisch designed. A configuration of the resin bed in is particularly preferred Form of a cylindrical ring, so that the system can be operated as a ring flow.

For the design of the first (biological) treatment level, there are ver different options. One is to daisy chain one Nitrification stage, in the z. B. is oxidized in a fixed bed reactor ammonium (NH₄), a denitrification stage in which e.g. B. nitrate reduced to elemental nitrogen (N₂) and an ultrafiltration stage. The ultrafiltration level can optionally be set by a Clarifier and a gravel filter to be replaced. The task of the ultrafiltration stage or the secondary settling tank consists in holding back the activated sludge this is still available in the biological cleaning stage. It can be provided that a certain amount of excess sludge from the biological Cleaning stage removed and a thickener and a via a catch basin Sludge dewater is fed.

During the operation of the device according to the invention are in the adsor substances that are not biodegradable. So far it concerns the regenerable adsorber, these substances are in the regeneration phase removed from the adsorber. According to the invention, the resulting Re Generat subjected to a chemical wet oxidation in a reactor, wherein preferably ozone (O₃) is used as an oxidizing agent. The wet oxidation In particular, the reactor can also function as a column reactor with an inner concentric one Flow line tube and drive jet nozzle with insert tube, as in the EP 0 130 499 is described. The latter is a closed reactor vessel, which is vertical and concentric at a distance an outer jacket and an inner flow guide tube arranged to one another, as well as the liquid level and the upper gas on the outer jacket Has overflow defining collecting space, the inner, above the Reactor housing floor and flow ending below the liquid level guide tube Regenerate and a (especially oxygen-containing) gas through a nozzle  is fed. Waste water is also withdrawn from the closed reactor vessel and by means of a pump again in the upper region of the flow guide tube from Introduced above via a drive jet nozzle, through the nozzle outlet cross section a plug-in pipe is guided in the middle at a distance, which extends into the vacuum area of the Drive jet nozzle is sufficient and in connection with a gas-containing space stands.

The ozone used in the reactor can come from a special ozone generator to provide. It is also advantageous to the reactor Add hydrogen peroxide (H₂O₂). Due to the oxidation in the reactor the non-biodegradable pollutants are partially oxidized. This happens in the The device according to the invention is particularly effective since the oxidation is only possible with the Regenerate is carried out in which the pollutants of the wastewater are concentrated are located. In this way, there can be significant savings Oxidizing agents (ozone) come. In addition, the entire plant can be used for wet oxidation be made considerably smaller than is the case with systems according to the Technology is the case since the latter covers up the total amount of wastewater to a treatment must undergo the discharge limit in the device according to the invention however, partial oxidation is sufficient. This enables significant ozone saving. The oxidation reaction turns non-biodegradable substances into biodegradable substances converted so that these from the regenerated stream removed and returned to the entire sewage treatment plant at the entrance can. It can be advantageous here before the introduction into the biological clarification stage remove excess ozone in a residual ozone destroyer.

The subject of the invention also includes a method for cleaning waste water sern in one of the devices described above, in which the waste water in a is biologically clarified in the first stage, then in a second stage with Ad sorber is cleaned to final values, and finally the regenerate of regenerierba Ren adsorber is chemically cleaned in a third stage.

The advantage of this method is that first all with common methods biodegradable substances are removed, and then those in it Processes not recorded pollutants are retained in the adsorbers. Here is achieved in particular by working with a regenerable adsorber, that the system can be operated continuously and those retained there Pollutants can be destroyed chemically within the plant.  

An embodiment of the method in which in the second adsorber stage is preferred the wastewater is first led into at least one regenerable adsorber, which preferably consists of an adsorber resin fixed bed filter. After this The wastewater preferably reaches at least one regenerable adsorber further adsorber, which can be configured in particular as an activated carbon fixed bed filter can. By combining adsorption steps on different materials the spectrum of removable pollutants is optimized.

The wastewater passes through a special one in the regenerable adsorber Embodiment of the method, a first layer, preferably not biologically or substances that are difficult to degrade, in particular humic acids, are adsorbed, and then a second layer in which a further Ab COD content is reduced. This lowering means that downstream Filter relieved.

The regenerable adsorber is preferably designed as a ring flow in which Waste water or the regrind alternately from outside to inside is passed through the layers of the adsorber. This is one for the Adsorp tion particularly favorable flow situation achieved.

In a further embodiment of the method according to the invention, the Ab water after the regenerable adsorber in a second adsorber stage, which with Ak Charcoal is filled. The activated carbon is removed after it has been fully loaded distant and preferably reactivated, the reactivation in particular in one High temperature reactivation process can be done. After reactivation stands the activated carbon is available for reuse in the cleaning system.

The method according to the invention works in the biological preliminary clarification stage especially through the series connection of several process steps: For this nitrification belongs first, in which Am monium is oxidized to nitrate. At the same time, aerobic COD degradation takes place. By The addition of sodium hydroxide solution is the optimal pH value for biological conversion regulated. Furthermore, the activated sludge is preferably used during the nitrification mixture stirred and aerated.

After nitrification, denitrification takes place, with nitrates becoming an elementary stick material can be reduced. This is preferably done with stirring and metering of organically bound carbon, e.g. B. in the form of acetic acid or metha nol.  

Finally, the biomass is concentrated and separated in one Ultrafiltration system or a clarifier with a gravel filter. The on Enriched biomass then becomes the first stage of the biological process Nitrification stage, fed again. Furthermore, a certain amount of Excess sludge can be removed from the circuit and thickened and To be treated. The wastewater freed from the biomass arrives on the other hand, in the process stage of treatment described above to the Adsorbers.

The regenerable adsorbers are preferably alternately either in the Adsorption work phase or operated in the regeneration work phase. This can ensure that the entire system is continuous without sub refractions works.

The regeneration of the adsorbers is preferably carried out in a countercurrent process, i. H. the regenerate flows through the adsorber against the flow direction of the waste water. In particular, it is preferred according to the invention to use dilute sodium hydroxide solution Use (NaOH), preferably with a concentration of 3 to 6%, particularly preferably 4%, a flow velocity of 0.0001 to 0.01 m / s and with a Volume of caustic soda, five to ten times the bed volume corresponds.

The regenerate is a chemi after leaving the adsorber in a reactor subjected to wet oxidation, preferably with ozone and / or hydrogen peroxide is carried out. Through regeneration with dilute sodium hydroxide solution and adding hydrogen peroxide creates an excess of OH an ions, which leads to an accelerated formation of unspecifically oxidative OH-Radi kalen from ozone. This increases the effectiveness of chemical wet oxidation considerably improved. Because the radical oxidation of pollutants according to newer ones Research results represent a first order response, the sales speed due to the very high concentration in the regenerate stream increases, so that the ozone reactor has a smaller volume than at normal concentration in Wastewater needed.

The inventive method also provides that the regenerate after the All or part of the wet oxidation of the sewage treatment plant in the biological treatment stage again is supplied because the previously non-biodegradable substances through the (Partial) oxidation have become biodegradable. If necessary, this takes place before  the supply of the regrind to the biological clarification stage a conversion of the Ozone in oxygen (O₂) in a residual ozone destroyer.

The regenerated in this way enriched with oxygen is then z. B. the nitri fication level of the biological clarification stage. By enrichment with acid Substance can save on the necessary supply air in the nitrifica tion level can be reached. The air compressors can therefore be built in a smaller size sizes are used, which leads to cost advantages.

The regenerate can be circulated once or several times through the adsorber be performed. Then it gets to chemical wet oxidation, or it can be bypassed in the bypass. Through these variations The procedure can be flexibly adapted to different conditions of the Klä tion and wastewater pollution.

Another variant of the method according to the invention is that Division of the resin beds into two single beds and selective adsorption Desorption can be done. This can e.g. B. look so that in first resin bed with the adsorption in the alkaline range and the desorption Methanol, and in the second resin bed the adsorption in the acidic range and the Desorption can be carried out with sodium hydroxide solution, and that the regenerate from first resin bed on the chemical wet oxidation of the denitrification stage and that Regenerate from the second resin bed via the chemical wet oxidation of the nitrification stage is fed. By setting the optimal conditions in each case the adsorption behavior of the resins can be optimized. Furthermore, one takes place Optimally adapted further processing in the substances retained in the adsorbers of pollutants in the biological clarification stage.

A preferred use of the device according to the invention and that he Processes according to the invention for the purification of highly contaminated wastewater, such as that e.g. B. occur as industrial waste water or in the form of landfill leachate.

In the following an embodiment of the invention will be described with the help of FIGS. 1 to 6.

Fig. 1 shows a cleaning device using ultrafiltration.

Fig. 2 shows a cleaning device employing a secondary sedimentation tank.

Fig. 3 shows a resin adsorber with double bed in a tier arrangement.

Fig. 4 shows a resin adsorber with a double bed as a ring flow.

Fig. 5 shows the resin adsorber in parallel.

Fig. 6 shows the resin adsorber in series connection.

In the device shown in FIG. 1, the contaminated wastewater first reaches nitrification stage 1 . Here, among other things, the ammonium is converted into nitrate, and the addition of sodium hydroxide solution 2 leads to the setting of an optimal pH.

After nitrification, the wastewater reaches denitrification level 3 . Here the nitrate with the addition of organically bound carbon 4 , z. B. in the form of acetic acid, and optionally with the addition of phosphoric acid (H₃PO₄) reduced to elemental nitrogen.

Finally, the waste water reaches the ultrafiltration system 5 , which retains the biomass and discharges it via a line 10 . For the most part, the biomass is returned to the entrance of the biological clarification stage, ie nitrification level 1 . In some cases, however, an excess sludge is also withdrawn from this circuit and treated further via a thickener 11 and a sludge dewatering 12 .

The permeate passing through the ultrafiltration system reaches the adsorption stage via a line 6 . Here, 1 regenerable adsorber two fixed-bed filter 7 are in the apparatus of Fig. A, 7 b arranged in parallel to each other. These can be regenerated. They are operated alternately in the adsorption or regeneration mode.

Behind the adsorbers 7 a, 7 b, 7 c there is at least one further adsorber 8 which consists of activated carbon and which the clarified waste water leaves via line 9 . The various adsorbers each extract specific pollutants from the wastewater. The resin adsorbers primarily adsorb substances that are difficult to biodegrade and cannot be adsorbed by activated carbon and lead to a further reduction in the COD value.

For the regeneration of the resin adsorbers 7 a, 7 b, 5% sodium hydroxide solution is fed from a reservoir 13 via a feed line 14 a to the adsorber 7 a or 7 b switched to regeneration in each case. This passes through the adsorber in the opposite direction to the wastewater and leaves it as a so-called regenerate again via line 14 b. The regenerate can be sent several times in a circuit through the adsorber via the reservoir 13 until it contains a sufficient load of desorbed pollutants.

The regenerate thus enriched with pollutants is then fed to a reactor 15 for chemical wet oxidation. This reactor receives 16 ozone from an ozone generator and 18 hydrogen peroxide via a further feed line. Partial oxidation of the non-biodegradable pollutants takes place in the reactor 15 , so that they now obtain a biodegradable form. They can therefore be fed to the entrance of the wastewater treatment plant, ie nitrification stage 1 . This is done by interposing a residual ozone destroyer 17 , which converts to oxygen via excess ozone.

Fig. 2 shows a variant of the device described in Fig. 1, in which the ultra filtration system 5 is replaced by a clarifier 20 and a downstream gravel filter bed 19 . Functionally, these two variants behave the same.

Fig. 3 shows a resin adsorber with double bed in a tier arrangement. This resin adsorber can consist of a square or cylindrical container 24 a, which contains a feed line 22 a and a discharge line 22 b for the water to be clarified. During the regeneration of the adsorber, the supply of the regenerate (sodium hydroxide solution) takes place in a countercurrent process via the supply line 23 a or the discharge line 23 b.

The adsorber itself is made up of two layers, a first layer 25 , which consists of a weakly basic anion exchanger, and a second layer 26 , which consists of macroporous crosslinked polystyrene-divinylbenzene copolymers or of acrylic acid derivatives. While in the first layer mainly the non-biodegradable pollutants, consisting of large macromolecules such as B. humic acids are retained, a further reduction in the COD value takes place in the second layer.

Fig. 4 shows a special embodiment of the aforementioned adsorber bed. With regard to the management of wastewater and regenerate, what has been said regarding FIG. 3 applies accordingly. However, the adsorber vessel 24 b is designed as a ring flow. This means that the wastewater or the regenerate flows from the outside in and vice versa through the adsorber beds. Since the adsorber again consists of two different adsorber beds 25 , 26 , the flow through these beds takes place alternately from outside to inside or from inside to outside. This special flow form ensures improved conditions for the adsorption.

Fig. 5 shows two resin adsorbers 7 a, 7 b in parallel. While z. B. the adsorber 7 a is in the "adsorption" phase, the adsorber 7 b is in the "regeneration" phase. Continuous operation is achieved by alternating switching.

Fig. 6 shows three resin adsorbers 7 a, 7 b, 7 c in series connection. While the adsorbers 7 a and 7 b are in the “adsorption” phase, the adsorber 7 c is in the “regeneration” phase. After the regeneration of the adsorbers 7c 7 b and 7 c in the phase of "adsorption" and switched adsorber 7 a is regenerated. As a result, each adsorber is regenerated in turn and the optimal counterflow adsorption is achieved.

Claims (27)

1. Device for the purification of waste water, consisting of a combination of biological, chemical and physical treatment stages, characterized in that it consists of

• A) a first stage ( 1 , 3 , 5 ) for the biological pre-treatment of the wastewater with a drain ( 6 ) for the pre-treated water,
• B) a second treatment stage arranged behind the discharge line ( 6 ) and consisting of at least one adsorber ( 7 a, 7 b, 7 c, 8 ) with a discharge line ( 9 ) for the treated waste water, at least one of the adsorbers ( 7 a , 7 b, 7 c) is regenerable, and
• C) a chemical cleaning stage ( 13 , 15 , 16 , 17 , 18 ), which is connected to the regenerable adsorber ( 7 a, 7 b, 7 c) via inlet ( 14 a) and outlet ( 14 b) for regeneration.

2. Device according to claim 1, characterized in that in the second treatment stage B) behind the derivative ( 6 ) at least one regenerable adsorber ( 7 a, 7 b, 7 c), preferably an adsorber resin fixed bed filter, is arranged. 3. Apparatus according to claim 2, characterized in that behind the regenerable Ad sorber ( 7 a, 7 b, 7 c) at least one further adsorber ( 8 ), preferably an activated carbon fixed bed filter, is arranged, on which the derivative ( 9 ) for the treated wastewater. 4. Device according to one of claims 1 to 3, characterized in that the regenerable adsorber ( 7 a, 7 b, 7 c) consists of at least two layers ( 25 , 26 ), preferably the first layer ( 25 ) of a weak basic anion exchanger and / or the second layer ( 26 ) of macroporous adsorber polymers, preferably cross-linked polystyrene-divinylbenzene copolymers or acrylic acid derivatives. 5. The device according to claim 4, characterized in that the first layer ( 25 ) is selected so that it primarily adsorbs biodegradable or poorly degradable substances, preferably humic acids. 6. Device according to claims 4 to 5, characterized in that the adsorbent particles of the second layer ( 26 ) have an average pore diameter of 10 nm, a pore volume of 0.3 to 0.4 cm³ / g and an inner surface of 700 to 1,500 m² / g has. 7. Device according to one of claims 1 to 6, characterized in that the adsorber container ( 24 a, 24 b) and the adsorber bed are square or cylindrical, in particular that the resin bed forms a cylinder ring ( 24 b) and is thus designed as a ring flow . 8. Device according to one of claims 1 to 7, characterized in that the first treatment stage A) consists of the series connection

• a) optionally a nitrification stage ( 1 ) and / or
• b) a denitrification stage ( 3 ) and / or
• c) an ultrafiltration stage ( 5 ), in the retentate circuit of which a thickener ( 11 ) and a sludge dewater ( 12 ) can be arranged.

9. Device according to one of claims 1 to 7, characterized in that the first treatment stage A) consists of the series connection

• a) optionally a nitrification stage ( 1 ) and / or
• b) a denitrification stage ( 3 ) and / or
• c) a secondary clarifier ( 20 ) and / or
• d) a gravel filter ( 19 ).

10. Device according to one of claims 1 to 9, characterized in that the chemical cleaning stage C) ( 13 , 15 , 16 , 17 , 18 ) contains a reactor ( 15 ) for the chemical wet oxidation of the regenerate supplied via the line ( 14 b) , wherein the reactor ( 15 ) can be configured in particular as a reactor column with an inner concentric flow line tube, in which a drive jet nozzle with an insertion tube is arranged. 11. The device according to claim 10, characterized in that the reactor ( 15 ) is connected to

• a) a supply line for the regenerate and
• b) optionally a supply line from an ozone generator ( 16 ) and / or
• c) a feed line ( 18 ) for hydrogen peroxide and / or
• d) a derivation for treated regenerate, which possibly leads to a residual ozone destroyer ( 17 ), which is preferably connected to the entrance of the first biological treatment stage ( 1 ).

12. A process for the purification of waste water in a device according to one of claims 1 to 11, characterized in that

• A) the wastewater is biologically pre-treated in a first stage ( 1 , 3 , 5 ),
• B) the waste water is then cleaned in a second stage by means of adsorbers ( 7 a, 7 b, 7 c, 8 ) to final values, and
• C) the regenerate of the regenerable adsorbers ( 7 a, 7 b, 7 c) is chemically cleaned in a third stage ( 13 , 15 , 16 , 17 , 18 ).

13. The method according to claim 12 in a device according to claim 2, characterized in that the second stage B) supplied wastewater passed directly through at least one regenerable adsorber ( 7 a, 7 b, 7 c), preferably an adsorber resin fixed bed filter becomes. 14. The method according to claim 13 in a device according to claim 3, characterized in that the regenerable adsorber ( 7 a, 7 b, 7 c) leaving wastewater is passed through at least one further adsorber ( 8 ), preferably an activated carbon fixed bed filter, and then leaves the system clarified via the derivative ( 9 ). 15. The method according to any one of claims 12 to 14 in a device according to one of claims 4 to 6, characterized in that the waste water in the regenerable adsorber ( 7 a, 7 b, 7 c) first passes through a first layer ( 25 ) , in which preferably biodegradable or only poorly degradable substances, in particular humic acids, are adsorbed, and then a second layer ( 26 ), in which the COD content is preferably reduced by adsorption. 16. The method according to any one of claims 13 to 15 in a device according to claim 7, characterized in that the adsorber ( 7 a, 7 b, 7 c) works as a ring flow, the wastewater / regenerate alternating meandering alternating from the outside to the inside or from the inside to the outside through the layers of the adsorber. 17. The method according to any one of claims 12 to 16 in a device according to An saying 3, characterized in that the second adsorber stage with Ak tivkohle is filled, which is removed after loading and preferably reactivated is, especially in a high temperature reactivation process, so that it is available for re-use. 18. The method according to any one of claims 12-17 in a device according to claim 8 or 9, characterized in that the biological preliminary treatment A) is carried out by

• a) optionally nitrification ( 1 ), preferably under optimal pH values, which can be produced by metering in sodium hydroxide solution, and preferably with stirring and aerating the activated sludge mixture, so that in particular ammonium is oxidized to nitrate and aerobic COD degradation takes place, and or
• b) subsequent denitrification ( 3 ), preferably with stirring and metering of organically bound carbon, in particular in the form of acetic acid or methanol, so that nitrate is reduced to elemental nitrogen, and / or
• c) subsequent concentration and separation of the biomass in an ultrafilter ( 5 ) or a secondary clarifier ( 20 ), the biomass preferably being returned to the nitrification stage ( 1 ) via the compound ( 10 ), while excess sludge is removed and thickened ( 11 ) and dewatered ( 12 ) can be.

19. The method according to any one of claims 12 to 18, characterized in that at least two regenerable adsorbers ( 7 a, 7 b, 7 c) are cyclically alternately in the adsorption work phase or in the regeneration work phase. 20. The method according to any one of claims 12 to 19, characterized in that the adsorbers ( 7 a, 7 b, 7 c) are regenerated in countercurrent. 21. The method according to any one of claims 12 to 20, characterized in that the adsorbers ( 7 a, 7 b, 7 c) mitver diluted sodium hydroxide solution are regenerated, preferably with 3 to 6%, particularly preferably 4% sodium hydroxide solution, at a flow velocity of 0.0001 to 0.01 m / s and with 5 to 10 bed volumes of sodium hydroxide solution. 22. The method according to any one of claims 12 to 21, characterized in that the regenerate is passed through a re actuator ( 15 ) for chemical wet oxidation, preferably using ozone and / or hydrogen peroxide. 23. The method according to claim 22, characterized in that in the reactor ( 15 ) the formation of OH radicals is accelerated, preferably by producing an excess of OH⁻ ions, for. B. by using lye, in particular sodium hydroxide solution and / or metering in of hydrogen peroxide. 24. The method according to any one of claims 22 to 23, characterized in that the regrind after the wet oxidation ( 15 ) is wholly or partly fed back to the first biological clarification stage ( 1 ), with any destruction of the residual ozone ( 17 ) he follows. 25. The method according to any one of claims 19 to 24, characterized in that the regenerate stream passes through the adsorber ( 7 a, 7 b, 7 c) one or more times in the circuit and is then fed to the chemical wet oxidation or bypassed the chemical wet oxidation can be. 26. The method according to any one of claims 12 to 25, characterized in that by the division of the resin beds selective adsorption and desorption were carried out in two single beds can be, preferably by the adsorption in the first resin bed alkaline range and desorption with methanol, in the second resin bed  Adsorption in the acidic range and desorption carried out with sodium hydroxide solution and that the regenerate from the first resin bed through the chemical Wet oxidation of the denitrification stage and the regenerate from the second resin bed is fed to the nitrification stage via the chemical wet oxidation. 27. Use of the device or the method according to one of claims 1 to 26 for the purification of highly contaminated wastewater such. B. Industry water and landfill leachate.