DE212021000106U9 - Oxidation ditch device for integrated double circulation of municipal wastewater - Google Patents

Abstract

Oxidation ditch device for the integrated double circulation of municipal wastewater, characterized in that it comprises an anaerobic area (A1), an anox area, an aerobic area and a secondary clarifier (D), which are connected one after the other, the anox area having a first anox area (B1) and a second Anox area (B2), the aerobic area comprising a first aerobic area (C3) and a second aerobic area (C4), a reflux pump (7) being arranged between the anox area and the aerobic area.

Description

TECHNICAL AREA

The present invention relates to the field of wastewater treatment and, more particularly, to an oxidation ditch apparatus for the integrated dual circulation of municipal wastewater.

STATE OF THE ART

With the rapid development of the social economy and the growing population, the consumption of resources and energy has accelerated to some extent. The development of industrialization and irrational grazing have led to the continuous deterioration of the aquatic environment, which has resulted in a shortage of available freshwater resources, which is why the problem of water supply has become an urgent problem in many countries.

The scarcity of water resources poses a serious threat to the development of human society. The recovery and reuse of wastewater is considered to be the best strategy for meeting current and future water needs. As the public and government became more aware of environmental protection, China's wastewater treatment capacity has also expanded rapidly. Wastewater treatment includes primary and secondary treatment processes and sometimes advanced treatment processes using various biological, physical and chemical techniques. The wastewater treatment processes used in sewage treatment plants in China are currently divided into conventional activated sludge processes, anaerobic-anoxic-aerobic (A ² / O), anaerobic-aerobic (A / O), batch reactor (SBR) with sequencing and oxidation ditch. The efficiency of the wastewater treatment plant depends not only on the process, but also on the size of the wastewater treatment plant. The discharge and treatment efficiency of wastewater and sewage treatment plants differ from region to region. The influence of various treatment technologies on sludge utilization is increasing in China. Due to the heterogeneity of economic development, economic growth is faster in the eastern region, especially in Zhejiang and Jiangsu. This variability depends on many factors including China's large population (1.41 billion), rapid economic growth, industrialization, urbanization, and insufficient investment in infrastructure. However, the state investment is mainly used for the construction and operation of sewage treatment plants, which have some shortcomings such as: B. long construction time, high costs and high energy consumption. These inadequacies therefore mean that the sewage treatment plant cannot meet the required discharge standards.

With the acceleration of urbanization and industrialization, large amounts of nutrients such as nitrogen and phosphorus are present in the domestic sewage we divert, which leads to the rapid proliferation of algae and other plankton and accelerates the eutrophication of water bodies, which affects our health and the aquatic ecological Has done great damage to the environment. Therefore, research on nitrogen and phosphorus removal technology from domestic sewage has received a great deal of attention and attention in the field of water treatment. To this end, the present invention aims to provide an oxidation ditch device with low power consumption and economic applicability and a method of use for integrated double circulation of urban sewage.

Luo et al. took activated sludge from a sewage treatment plant in a city as a research subject and used 16srrna high-throughput technology to study gene sequencing of bacterial community features in the oxidation ditch system of a well-functioning sewage treatment plant in a cold region (Xinjiang). The results show that the inlet temperature in winter and spring is 7 to 12 ° C and the inlet temperature in summer 13 to 17 ° C and the sludge volume index (SVI) of the sample is between 51 and 74 ml / g. The average removal rates for chemical oxygen demand (COD), biochemical oxygen demand (BOD5), suspended solids (SS), ammonia ^{nitrogen (NH4 +} -N), total nitrogen (TN) and total phosphorus are 94%, 95%, 95% , 91%, 73% and 89%, respectively. The average removal rates for chemical oxygen demand (COD), biochemical oxygen demand (BOD5), ammonia ^{nitrogen (NH4 +} -N), total nitrogen (TN), and total phosphorus in this study are 94.2%, 98.26%, 98 , 25%, 72.2% and 91.87%, respectively. With the exception of the somewhat lower parametric values for total nitrogen, the parametric values for other indicators are higher than in the study by Luo et al.

CONTENT OF THE PRESENT INVENTION

In order to solve the ammonia nitrogen load in domestic sewage and in the water environment, the problem of the high concentration of COD, BOD, ammonia nitrogen, TN and TP feed water in extensive sewage is reduced. It is an object of the present invention to provide an oxidation ditch device for integrated dual circulation of municipal sewage, whereby the Ammonia nitrogen pollution can be effectively reduced so that the treated wastewater can be used as circulating make-up water for reuse.

• Oxidationsgrabenvorrichtung zur integrierten Doppelzirkulation von kommunalem Abwasser, umfassend einen Anaerobbereich, einen Anoxbereich, einen Aerobbereich und ein Nachklärbecken, die nacheinander verbunden sind, wobei der Anoxbereich einen ersten Anoxbereich und einen zweiten Anoxbereich umfasst, wobei der Aerobbereich einen ersten Aerobbereich und einen zweiten Aerobbereich umfasst, wobei eine Rückflusspumpe zwischen dem Anoxbereich und dem Aerobbereich angeordnet ist, wobei die aus dem Anaerobbereich in den Anoxbereich eingetragene Mischflüssigkeit des Abwassers durch die interne Rückflusspumpe zugeführt wird, wobei der Rückflussschlamm mit einer großen Menge an Nitratstickstoff in dem Aerobbereich verwendet wird, um eine stabile Entfernung von Nitratstickstoff in der Mischflüssigkeit des Abwassers im Adsorptionsprozess und im Stoffwechselprozess von organischen Stoffen durch denitrifizierende Bakterien unter der Wirkung des zweiten Tauchrührers unter Ausnutzung der anoxischen Umgebung zu erreichen, um den Entfernungseffekt von Ammoniakstickstoff und Gesamtstickstoff zu fördern.

An object of the present invention is achieved by at least one of the following technical solutions:

• Oxidation ditch device for integrated double circulation of municipal wastewater, comprising an anaerobic area, an anox area, an aerobic area and a secondary clarifier, which are connected one after the other, the anox area comprising a first anox area and a second anox area, the aerobic area comprising a first aerobic area and a second aerobic area, wherein a reflux pump is arranged between the anox area and the aerobic area, wherein the mixed liquid of the sewage introduced from the anaerobic area into the anox area is supplied by the internal reflux pump, the reflux sludge with a large amount of nitrate nitrogen in the aerobic area is used to achieve a stable removal of nitrate nitrogen in the mixed liquid of the wastewater in the adsorption process and in the metabolic process of organic substances by denitrifying bacteria under the action of the second immersion stirrer using the anoxic environment level to promote the removal effect of ammonia nitrogen and total nitrogen.

It is preferably provided that the anaerobic area is provided with an inlet, a first connection port being arranged between the anaerobic area and the anox area, a second connection port being arranged between the anox area and the aerobic area, a third connection port being arranged between the aerobic area and the secondary clarifier is.

It is further preferably provided that the first connection port is arranged at a lower end of a partition between the anaerobic area and the anoxic area, the second connection port being arranged at a lower end of a partition between the anoxic area and the aerobic area, the third connection port being located at a lower end End of a partition between the aerobic area and the anaerobic area of the secondary clarifier and the anox area is arranged.

It is preferably provided that a first bypass wall is arranged between the first anox area and the second anox area, a second bypass wall being arranged between the first aerobic area and the second aerobic area, the aerobic area being provided with a partition wall, with a self-priming pressure flow aerator in each case on the Partition between the first aerobic area and the second aerobic area is arranged to form a cyclical flow between the first aerobic area and the second aerobic area, whereby the effects of enhanced nitrogen and phosphorus removal and the removal of organic pollutants are achieved, wherein the self-priming pressure flow aerator on is arranged both ends of the partition wall of the aerobic area, whereby the energy consumption of the ventilation fan is saved and the maintenance time and the maintenance costs of the ventilation system in the operating process can be reduced.

It is preferably provided that the aerobic area is provided with a ventilation fan for ventilation in the aerobic area.

It is preferably provided that the secondary clarifier is provided with a drainage channel, a sludge outlet and an emptying pipe as well as a backflow channel, the drainage channel being provided with an outlet, a sludge return pipe being arranged between the backflow channel and the anaerobic area, the drainage channel and the backflow channel on the upper ends of the secondary clarifier are arranged.

It is preferably provided that the bottom of the secondary clarifier is provided with a ventilation pipe for sludge removal or for maintenance. The integrated construction of each treatment area is carried out, and the transportation of the mixed liquid of the sewage is carried out through the connection port to reduce the construction area of the structure and the amount of laying the pipelines, while reducing the pressure loss, reducing the construction of the intermediate elevator and the Investment and operating costs are reduced.

It is preferably provided that a first immersion stirrer is installed in the anaerobic area, with a second immersion stirrer being installed in the anox area, with a third immersion stirrer being installed in the aerobic area.

It is preferably provided that the internal reflux pump uses a propeller pump with a large delivery rate and a low delivery head. Not only can it reduce the energy consumption of the reflux during operation, but it can also be installed on the pool wall to save the investment of building a reflux pumping station.

It is preferably provided that the drainage channel is provided with a water collecting pan for collecting a supernatant after the sludge water separation in the secondary clarifier to the drainage channel, a scraper rope suction machine being installed in the secondary clarifier, the device being provided with a sludge return pump for returning the sludge to the return flow channel.

Preferably, it is provided that after the sludge water separation, the sludge settles in the middle and lower part of the secondary clarifier, and during the back and forth movement of the scraper rope suction machine, the sludge pump lifts the sludge into the backflow channel, a mud backflow pipe being arranged between the backflow channel and the anaerobic area to form a reflux using the level difference between the reflux channel and the anaerobic area, thereby reducing the construction investment and operating costs for the construction of the reflux pumping station.

1. (a) Das Abwasser wird mit dem Rückflussschlamm aus dem Nachklärbecken in dem Anaerobbereich gemischt und einer anaeroben Behandlung unterzogen, um in den Anoxbereich einzutreten;
2. (b) Die Mischflüssigkeit des Abwassers in Schritt wird mit der Rückflussflüssigkeit aus dem Aerobbereich in dem Anoxbereich gemischt und einer anoxischen Behandlung unterzogen, um in den Aerobbereich einzutreten;
3. (c) Die Mischflüssigkeit des Abwassers in Schritt wird nach aerober Behandlung in dem Aerobbereich in den Anoxbereich zurückgeführt und tritt in das Nachklärbecken ein;
4. (d) Die Mischflüssigkeit des Abwassers in Schritt wird nach dem Absetzen im Nachklärbecken aus dem Auslass abgelassen, und der abgesetzte Schlamm wird in den Anaerobbereich zurückgeführt.

A method of wastewater treatment of an oxidation ditch device for integrated double circulation of urban wastewater according to the above claim, comprising the following steps:

1. (a) The wastewater is mixed with the reflux sludge from the secondary clarifier in the anaerobic area and subjected to anaerobic treatment to enter the anox area;
2. (b) The mixed liquid of the waste water in step is mixed with the reflux liquid from the aerobic area in the anoxic area and subjected to an anoxic treatment to enter the aerobic area;
3. (c) The mixed liquid of the wastewater in step is returned to the anox area after aerobic treatment in the aerobic area and enters the secondary clarifier;
4. (d) The mixed liquid of the wastewater in step is drained from the outlet after settling in the secondary clarifier, and the settled sludge is returned to the anaerobic area.

It is preferably provided that the mixed liquid of the waste water circulates in the anox area between the first anox area and the second anox area.

It is preferably provided that the mixed liquid of the waste water circulates in the aerobic area between the first aerobic area and the second aerobic area.

It is preferably provided that the mixed liquid of the waste water in the anaerobic area is used to release phosphorus in the phosphorus-enriching particles in the mixed liquid of the waste water in the metabolic process of organic substances by anaerobic bacteria under the effect of the pressure flow of the immersion stirrer using the anaerobic environment, which the provide necessary conditions for the excessive phosphorus absorption process in the aerobic area;
wherein the mixed mixed liquid of the sewage in the anox area is used to achieve stable removal of nitrate nitrogen in the mixed liquid of the sewage in the adsorption process and in the metabolic process of organic matter by denitrifying bacteria under the action of the immersion stirrer using the anoxic environment to achieve the removal effect to promote ammonia nitrogen and total nitrogen;
wherein the mixed liquid of the sewage in the aerobic area is used to achieve the removal of BOD and COD _cr carbon source pollutants in the mixed liquid of the sewage in the adsorption process and in the metabolic process of organic matter by aerobic bacteria under the action of the submersible stirrer using the aerobic environment to create carbon dioxide and water; wherein the phosphorus-enriching bacteria in the aerobic environment are used to excessively absorb the phosphorus element released in the anaerobic environment and then to adsorb the suspended matter in the mixed liquid of the sewage and the precipitates formed in the biochemical process; wherein the nitrogen source pollutants in the mixed liquid of the sewage are converted to nitrate nitrogen by nitrification in an aerobic environment and then returned to the anox area by the internal reflux pump;
The circulation area of the mixed liquid of the sewage entering the secondary clarifier is greatly increased and the flow velocity for sludge settling is reduced, and the supernatant after the sludge water separation enters the drainage channel by collecting the water collecting pan and is then drained through the outlet via the drainage pipe into the fresh water tank ; the sludge settling in the middle and lower part of the secondary clarifier after the sludge water separation, and during the reciprocating movement of the scraper suction machine, the sludge pump lifts the sludge into the return channel.

In the present invention, after the integrated double circulation oxidation ditch device, the average concentration (for chemical oxygen demand) of COD is from 341.5 mg / L to 19.7 mg / L with an average Removal rate reduced by 94.2%, which reduces the COD load on the sewage station. The average concentration of BOD is reduced from 149.6 mg / L to 2.58 mg / L with an average removal rate of 98.2%. The average concentration of ammonia nitrogen is reduced from 33.4 mg / L to 0.57 mg / L with an average removal rate of 98.2%. The average concentration of TN is reduced from 41.7 mg / L to 11.4 mg / L with an average removal rate of 72.2%. The average concentration of TP is reduced from 3.17 mg / L to 0.24 mg / L with an average removal rate of 91.8%.

• (1) Oxidationsgrabenvorrichtung zur integrierten Doppelzirkulation von kommunalem Abwasser der vorliegenden Erfindung weist die Eigenschaften eines einfachen Strukturbetriebs und niedriger Kosten auf, wodurch die Investitions- und Betriebskosten weiter reduziert und die wirtschaftlichen Vorteile verbessert werden können;
• (2) Die vorliegende Erfindung reduziert die ursprüngliche Konzentration von COD, BOD, Ammoniakstickstoff, TN und TP, die in die Kläranlage eintreten, wodurch die Entfernungsrate des Abwassers wirksam verbessert wird, was geeignete Bedingungen für die nachfolgende Stickstoffentfernungsbehandlung des Abwassers schafft.

The present invention has the following advantages and effects over the prior art:

• (1) The oxidation ditch device for integrated double circulation of municipal sewage of the present invention has the characteristics of simple structural operation and low cost, whereby the capital and running costs can be further reduced and the economic advantages can be improved;
• (2) The present invention reduces the original concentration of COD, BOD, ammonia nitrogen, TN and TP entering the sewage treatment plant, thereby effectively improving the removal rate of the sewage, which creates suitable conditions for the subsequent nitrogen removal treatment of the sewage.

Figure list

• 1 Figure 13 is an equipment diagram of the oxidation trench apparatus for integrated dual circulation of municipal sewage of the present invention.
• 2 Fig. 13 is a change graph of the COD concentration by the oxidation ditch device for integrated double circulation of municipal sewage of the present invention since it was put into operation for 120 days.
• 3 Fig. 13 is a graph of change in BOD concentration by the oxidation ditch device for integrated double circulation of municipal sewage of the present invention since it was put into operation for 120 days.
• 4th Fig. 13 is a graph of change in ammonia nitrogen concentration by the oxidation ditch device for integrated double circulation of municipal sewage of the present invention since it was put into operation for 120 days.
• 5 Fig. 13 is a graph of change in TN concentration by the oxidation ditch device for integrated double circulation of municipal sewage of the present invention since it was put into operation for 120 days.
• 6th Fig. 13 is a graph of change in TP concentration by the oxidation ditch device for integrated double circulation of municipal sewage of the present invention since the start-up for 120 days.

List of reference symbols

Al-

Anaerobic area,

B1-

first anox area,

B2-

second anox area,

C3-

first aerobic area,

C4-

second aerobic area,

D-

Secondary clarifier.

1-

Inlet,

2-

first immersion stirrer,

3-

first connection port,

4-

second immersion stirrer,

5-

first diversion wall,

6-

second connection port,

7-

Reflux pump,

8th-

Pressure flow aerator,

9-

second diversion wall,

10-

third immersion stirrer,

11-

Ventilation fan,

12-

third connection port,

13-

Sludge outlet and discharge pipe,

14-

Backflow channel,

15-

Sludge return pipe,

16-

Scraper rope suction machine,

17-

Water collecting pan,

18-

Drainage channel.

Detailed embodiments

The present invention is explained in more detail below in conjunction with the drawings and the embodiments. However, the embodiments do not imply any limitation on the scope of the present invention.

Embodiment 1

Oxidation ditch device for integrated double circulation of municipal wastewater, as in 1 shown comprising an anaerobic area A1 , an anox area ( B1 , B2 ), an aerobic area ( C3 , C4 ) and a secondary clarifier D. , where the anox area ( B1 , B2 ) a first anox area B1 and a second anox area B2 includes, the aerobic area ( C3 , C4 ) a first aerobic area C3 and a second aerobic area C4 includes;
being the anaerobic area A1 with an inlet 1 is provided, the first connection terminal 3 at a lower end of a partition between the anaerobic area A1 and the anox area ( B1 , B2 ) is arranged, the second connection terminal 6th at a lower end of a partition between the anox area ( B1 , B2 ) and the aerobic area ( C3 , C4 ) is arranged, the third connection terminal 12th at a lower end between the aerobic area ( C3 , C4 ) and the secondary clarifier D. is arranged, whereby the anox area ( B1 , B2 ) with a first diversion wall 5 is provided, whereby the aerobic area ( C3 , C4 ) with a second bypass wall 9 is provided, whereby the aerobic area ( C3 , C4 ) is provided with two partitions, with two self-priming pressure flow aerators 8th each at both ends of the partition are added, with the secondary clarifier D. with a drainage channel 18th , a sludge outlet and a discharge pipe 13th as well as a backflow channel 14th is provided, the drainage channel 18th and the reflux channel 14th at the upper ends of the secondary clarifier D. are arranged, the drainage channel 18th is provided with an outlet, a mud return pipe 15th between the reflux channel 14th and the anaerobic area A1 is arranged, wherein the bottom of the secondary clarifier is provided with a ventilation pipe. The integrated construction of each treatment area is carried out, and the transportation of the mixed liquid of the sewage is carried out through the connection port to reduce the construction area of the structure and the amount of laying the piping, while reducing the pressure loss, reducing the construction of the intermediate lift and the Investment and operating costs are reduced;
the first immersion stirrer 2 , the second immersion stirrer 4th and the third immersion stirrer 10 each in the anaerobic area A1 , the anox area ( B1 , B2 ) and the aerobic area ( C3 , C4 ) are built in;
being an internal reflux pump 7th on the partition wall of the aerobic area ( C3 , C4 ) and the anox area ( B1 , B2 ) is attached, with the internal reflux pump 7th a propeller pump with a large flow rate and low head is used. Not only can it reduce the energy consumption of the reflux during operation, but it can also be installed on the pool wall to save the investment of building a reflux pumping station;
where the aerobic area ( C3 , C4 ) is provided with two partitions, with two self-priming pressure flow aerators 8th respectively added at both ends of the partition, the self-priming pressure flow aerator 8th at both ends of the partition wall of the aerobic area ( C3 , C4 ) is arranged, whereby the energy consumption of the ventilation fan is saved and the maintenance time and the maintenance costs of the ventilation system are reduced in the operating process, wherein the aerobic area with a ventilation fan 11th is provided for ventilation in the aerobic area;
being the drainage channel 18th with a water collecting pan 17th for collecting a supernatant after the sludge water separation in the secondary clarifier D. is provided to the drainage channel;
being a scraper suction machine 16 in the secondary clarifier D. is built in, the device having a mud return pump for returning the mud to the return channel 14th is provided.

Embodiment 2

• 1). wobei das Abwasser durch die Förderleitung des Rohrnetzes vom Einlass 1 in den Anaerobbereich A1 eintritt, und die Mischflüssigkeit des Abwassers verwendet wird, um Phosphor in den phosphoranreichernden Partikeln in der Mischflüssigkeit des Abwassers im Stoffwechselprozess von organischen Stoffen durch anaerobe Bakterien unter der Wirkung der Druckströmung des ersten Tauchrührers 2 unter Ausnutzung der anaeroben Umgebung freizusetzen, was die notwendigen Bedingungen für den übermäßigen Phosphorabsorptionsprozess in dem Aerobbereich (C3, C4) bereitstellt; wobei gleichzeitig die durch das Rückflussrohr 15 eintretende die Mischflüssigkeit des Abwassers für die im biochemischen Prozess durch den Oxidationsgraben zur integrierten Doppelzirkulation erforderliche Schlammkonzentration sorgt; wobei die Mischflüssigkeit des Abwassers nach Beendigung des anaeroben Behandlungsprozesses durch den ersten Verbindungsanschluss 3 in den Anoxbereich (B1, B2) eintritt;
• 2). wobei die Mischflüssigkeit des Abwassers, die durch den Anaerobbereich A1 in dem Anoxbereich (B1, B2) eingegeben wird, wird mit einem Rückflussschlamm gemischt, der eine große Menge Nitratstickstoff in dem Aerobbereich (C3, C4) enthält, die durch die interne Rückflusspumpe 7 eingegeben wird, um eine stabile Entfernung von Nitratstickstoff in der Mischflüssigkeit des Abwassers im Adsorptionsprozess und im Stoffwechselprozess von organischen Stoffen durch denitrifizierende Bakterien unter der Wirkung des zweiten Tauchrührers 4 unter Ausnutzung der anoxischen Umgebung zu erreichen, um den Entfernungseffekt von Ammoniakstickstoff und Gesamtstickstoff zu fördern; wobei die Mischflüssigkeit des Abwassers nach Beendigung des anoxischen Behandlungsprozesses unter der Wirkung der Druckströmung des Tauchrührers 4 durch den zweiten Verbindungsanschluss 6 in den Aerobbereich (C3, C4) eintritt;
• 3). wobei die Mischflüssigkeit des Abwassers in dem Aerobbereich (C3, C4) verwendet wird, um die Entfernung von BOD- und COD_cr-Kohlenstoffquellenschadstoffen in der Mischflüssigkeit des Abwassers im Adsorptionsprozess und im Stoffwechselprozess von organischen Stoffen durch aerobe Bakterien unter der Wirkung des dritten Tauchrührers 10 unter Ausnutzung der aeroben Umgebung zu erreichen, um Kohlendioxid und Wasser zu erzeugen; nachdem die Stickstoffquellenschadstoffe in der Mischflüssigkeit des Abwassers durch Nitrifikation in einer aeroben Umgebung in Nitratstickstoff umgewandelt wurden, wird die interne Rückflusspumpe 7 erneut in den Anoxbereich (B1, B2) zurückgeführt, das heißt, nach dem zyklischen Wiederholungsprozess des obigen Schritts b wird der Zweck der Entfernung von Stickstoffquellenschadstoffen in der Mischflüssigkeit des Abwassers durch Nitrifikation und Denitrifikation vervollständigt, wobei Kohlendioxid, Stickstoff, Ammoniak und Wasser erzeugt werden; wobei die phosphoranreichernden Bakterien in der aeroben Umgebung verwendet werden, um das in der anaeroben Umgebung freigesetzte Phosphorelement übermäßig zu absorbieren und dann die Schwebstoffe in der Mischflüssigkeit des Abwassers und die im biochemischen Prozess gebildeten Fällungsstoffe zu adsorbieren und dann im nächsten Schritt zusammen mit dem Schlamm bei der Schlammwassertrennung auszutragen; wobei die verschiedenen Arten von Gasen, die durch die oben genannten erzeugt werden, aus jeder Struktur emittiert werden; wobei bisher durch den sequentiellen Behandlungsprozess des obigen Anaerobbereichs A1, des Anoxbereichs (B1, B2) und des Aerobbereichs (C3, C4) und des gleichzeitigen internen Rückfluss- und Überschussschlammrückflussverfahrens die zyklische und wiederholte biochemische A²O-Behandlung der Mischflüssigkeit des Abwassers abgeschlossen werden, und verschiedene Schadstoffe in der Mischflüssigkeit des Abwassers werden reduziert und behandelt; wobei sie dann über den dritten Verbindungsanschluss 12 in das Nachklärbecken D eintritt;
• 4). wobei die Zirkulationsfläche der in das Nachklärbecken D eintretenden Mischflüssigkeit des Abwassers stark vergrößert und die Strömungsgeschwindigkeit zur Schlammabsetzung verringert wird, um eine gute gemischte Bioflockung zu bilden, wodurch die Schlammabsetzgeschwindigkeit und der Schlammwassertrenneffekt des Nachklärbeckens D verbessert werden, und der Überstand nach der Schlammwassertrennung tritt durch das Sammeln der Wassersammelwanne 17 in den Ablaufkanal 18 ein und wird dann durch den Auslass über das Abflussrohr in den Frischwassertank abgelassen;
• 5). wobei sich der Schlamm nach der Schlammwassertrennung in den mittleren und unteren Teil des Nachklärbeckens D absetzt, und während der Hin- und Herbewegung der Kratzseilsaugmaschine 16 hebt die Schlammpumpe den Schlamm in den Rückflusskanal 14, wobei ein Schlammrückflussrohr 15 zwischen dem Rückflusskanal 14 und dem Anaerobbereich A1 angeordnet ist, um einen Rückfluss unter Verwendung der Füllstandsdifferenz zwischen dem Rückflusskanal 14 und dem Anaerobbereich A1 zu bilden, wodurch die Bauinvestitionen und Betriebskosten für den Bau der Rückflusspumpstation reduziert werden.

A method of wastewater treatment of an oxidation ditch device for integrated double circulation of municipal wastewater, comprising the following steps:

• 1). the sewage through the delivery line of the pipe network from the inlet 1 in the anaerobic area A1 enters, and the mixed liquid of the waste water is used to phosphorus in the phosphorus-enriching particles in the mixed liquid of the waste water in the metabolic process of organic substances by anaerobic bacteria under the action of the pressure flow of the first immersion stirrer 2 using the anaerobic environment to release what the necessary conditions for the excessive phosphorus absorption process in the aerobic area ( C3 , C4 ) provides; while at the same time passing through the reflux pipe 15th entering the mixed liquid of the wastewater ensures the sludge concentration required in the biochemical process through the oxidation ditch for integrated double circulation; wherein the mixed liquid of the sewage after the completion of the anaerobic treatment process through the first connection port 3 in the anox area ( B1 , B2 ) entry;
• 2). being the mixed liquid of the sewage passing through the anaerobic area A1 in the anox area ( B1 , B2 ) is entered is mixed with a reflux sludge containing a large amount of nitrate nitrogen in the aerobic area ( C3 , C4 ) by the internal reflux pump 7th is entered to a stable Removal of nitrate nitrogen in the mixed liquid of the wastewater in the adsorption process and in the metabolic process of organic substances by denitrifying bacteria under the action of the second immersion stirrer 4th taking advantage of the anoxic environment to promote the removal effect of ammonia nitrogen and total nitrogen; wherein the mixed liquid of the waste water after completion of the anoxic treatment process under the action of the pressure flow of the immersion stirrer 4th through the second connection port 6th in the aerobic area ( C3 , C4 ) entry;
• 3). where the mixed liquid of the wastewater in the aerobic area ( C3 , C4 ) is used to remove BOD and COD _cr carbon source pollutants in the mixed liquid of wastewater in the adsorption process and in the metabolic process of organic matter by aerobic bacteria under the action of the third immersion stirrer 10 to achieve taking advantage of the aerobic environment to generate carbon dioxide and water; After the nitrogen source pollutants in the mixed liquid of the sewage are converted to nitrate nitrogen by nitrification in an aerobic environment, the internal reflux pump becomes 7th again in the anox area ( B1 , B2 ) recycled, that is, after the cyclic repeating process of the above step b, the purpose of removing nitrogen source pollutants in the mixed liquid of the sewage is completed by nitrification and denitrification, generating carbon dioxide, nitrogen, ammonia and water; The phosphorus-enriching bacteria in the aerobic environment are used to excessively absorb the phosphorus element released in the anaerobic environment and then to adsorb the suspended matter in the mixed liquid of the sewage and the precipitates formed in the biochemical process and then in the next step together with the sludge to discharge the sludge water separation; the various types of gases generated by the above being emitted from each structure; being so far through the sequential treatment process of the above anaerobic area A1 , the anox area ( B1 , B2 ) and the aerobic area ( C3 , C4 ) and the simultaneous internal reflux and excess sludge reflux process, the cyclic and repeated A ² O biochemical treatment of the mixed liquid of the sewage are completed, and various pollutants in the mixed liquid of the sewage are reduced and treated; then via the third connection port 12th in the secondary clarifier D. entry;
• 4). being the circulation area of the in the secondary clarifier D. incoming mixed liquid of the sewage is greatly increased and the flow rate for sludge settling is reduced to form a good mixed bio-flocculation, whereby the sludge settling rate and the sludge water separation effect of the secondary clarifier D. can be improved, and the supernatant after the sludge water separation passes through the collecting of the water collecting pan 17th into the drainage channel 18th and is then drained through the outlet via the drain pipe into the fresh water tank;
• 5). after the sludge water separation, the sludge is in the middle and lower part of the secondary clarifier D. settles, and during the reciprocating movement of the scraper suction machine 16 the sludge pump lifts the sludge into the backflow channel 14th , being a mud return pipe 15th between the reflux channel 14th and the anaerobic area A1 is arranged to provide a return flow using the level difference between the return flow channel 14th and the anaerobic area A1 thereby reducing the construction investment and operating costs for the construction of the reflux pumping station.

In the present embodiment, the demonstration project of the newly designed oxidation ditch device is used for integrated double circulation of municipal sewage. Wastewater treatment scale: 10,000 tons / day, hydraulic retention time HRT: 8-12 days, sludge age: SRT = 15-22 days, concentration of the mixed liquid: MLSS = 3,000-4,500 mg / l, sludge load: Fw = 0.1-0.2 kgBOD ₅ / kgMLVSS, reflux ratio of the aerobic area C into the anox area B: 100-150%, reflux ratio of the sludge: 50-100%.

From the 2 , 3 , 4th , 5 and 6th it can be seen that the original average COD concentration of the sewage treatment plant under normal production conditions is 341.5 mg / l, the average BOD concentration 149.6 mg / l, the average ammonia nitrogen concentration 33.4 mg / l, the average TN concentration 41 , 7 mg / l and the average TP concentration is 3.17 mg / l. After treatment with this equipment, the COD concentration was greatly reduced to 19.7 mg / L compared to before, the average BOD concentration of the wastewater was greatly reduced to 2.58 mg / L, the average ammonia nitrogen concentration was greatly reduced to 0 , 57 mg / l, the average TN concentration was greatly reduced to 11.4 mg / l and the average TP concentration was also greatly reduced to 0.24 mg / l. The average removal rate has been increased from 72% to 98%, which helps to provide a sufficient source of carbon for denitrification and nitrogen removal, thereby lowering the wastewater treatment plant operating costs and improving the economic benefits.

So as to realize synchronous denitrification and phosphorus removal of nitrate nitrogen in the anox area, thereby achieving the purpose of stable removal of organic pollutants COD and nitrogen and phosphorus removal, the COD removal effect is improved, and the nitrification and denitrification and nitrogen and phosphorus removal efficiency is further improved. The main pollutant indicators of the wastewater from the basin meet or exceed the national and A standards. The integrated structure of the apparatus of the present invention has the characteristics of simple structural operation and low cost, whereby the investment and running costs can be further reduced.

The above embodiment is a preferred embodiment of the present invention, but the embodiment of the present invention is not limited by the above embodiment. All other changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principles of the present invention are deemed equivalent substitutions and are included within the scope of the present invention.

Claims (7)

Oxidation ditch device for integrated double circulation of municipal wastewater, characterized in that it comprises an anaerobic area (A1), an anox area, an aerobic area and a secondary clarifier (D), which are connected one after the other, the anox area having a first anox area (B1) and a second Anox area (B2), the aerobic area comprising a first aerobic area (C3) and a second aerobic area (C4), a reflux pump (7) being arranged between the anox area and the aerobic area. Oxidation ditch device for integrated double circulation of municipal wastewater according to Claim 1 , characterized in that the anaerobic area (A1) is provided with an inlet (1), a first connection port (3) being arranged between the anaerobic area (A1) and the anox area, with a second connection port (6) between the anox area and the Aerobic area is arranged, wherein a third connection port (12) is arranged between the aerobic area and the secondary clarifier (D). Oxidation ditch device for integrated double circulation of municipal wastewater according to Claim 2 , characterized in that the first connection port (3) is arranged at a lower end of a partition between the anaerobic area (A1) and the anoxic area, the second connection port (6) being arranged at a lower end of a partition between the anoxic area and the aerobic area wherein the third connection port (12) is arranged at a lower end of a partition between the aerobic area and the anaerobic area of the secondary clarifier (D) and the anox area (C). Oxidation ditch device for integrated double circulation of municipal wastewater according to Claim 1 , characterized in that a first diversion wall (5) is arranged between the first anox area (B1) and the second anox area (B2), a second diversion wall (9) being arranged between the first aerobic area (C3) and the second aerobic area (C4) is, wherein the aerobic area is provided with a partition, wherein a self-priming pressure flow aerator (8) is arranged on the partition between the first aerobic area (C3) and the second aerobic area (C4) to create a cyclic flow between the first aerobic area (C3) and to form the second aerobic area (C4), the aerobic area being provided with a ventilation fan (11) for ventilation in the aerobic area. Oxidation ditch device for integrated double circulation of municipal wastewater according to Claim 1 , characterized in that the secondary clarifier (D) is provided with a drainage channel (18), a sludge outlet and an emptying pipe (13) and a backflow channel (14), the drainage channel (18) being provided with an outlet, a sludge return pipe ( 15) is arranged between the backflow channel (14) and the anaerobic area (A1), the drainage channel (18) and the backflow channel (14) being arranged at the upper ends of the secondary clarifier (D), the bottom of the secondary clarifier (D) with a ventilation pipe for sludge removal or maintenance is provided. Oxidation ditch device for integrated double circulation of municipal wastewater according to Claim 1 , characterized in that a first immersion stirrer (2) is installed in the anaerobic area (A1), a second immersion stirrer (4) being installed in the anox area, a third immersion stirrer (10) being installed in the aerobic area, with the internal reflux pump (7) a Large flow and low head propeller pump used. Oxidation ditch device for integrated double circulation of municipal wastewater according to Claim 1 , characterized in that the drainage channel (18) is provided with a water collecting trough (17) for collecting a supernatant after the sludge water separation in the secondary clarifier (D) to the drainage channel, wherein a scraper rope suction machine (16) is installed in the secondary clarifier (D), wherein the device is provided with a sludge return pump for returning the sludge to the return channel (14).

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