CN110436629A - A sewage total nitrogen removal device and method - Google Patents

Abstract

The invention provides a device and a method for removing total nitrogen in sewage, which are characterized in that a deoxygenation reactor is additionally arranged at the front end of an anaerobic tank, and a deoxygenation agent is utilized to react with dissolved oxygen in inlet water of the anaerobic tank and return water of a secondary sedimentation tank, so that the dissolved oxygen concentration of the anaerobic tank and the dissolved oxygen concentration of an anoxic tank are reduced, the denitrification capability of the anaerobic tank is improved, and the removal of the total nitrogen in the sewage is improved.

Description

A sewage total nitrogen removal device and method

technical field

The invention relates to the field of sewage treatment, in particular to a sewage total nitrogen removal device and method.

Background technique

Nitrification and denitrification are the most convenient and energy-saving treatment methods for removing total nitrogen in sewage. The nitrification reaction is completed by aerobic autotrophic microorganisms. In an aerobic state, inorganic carbon is used as a carbon source to convert NH ₄ ⁺ into NO ₂ ^- , and then oxidized into NO ₃ ^- . The nitrification process can be divided into two stages. In the first stage, the ammonia nitrogen is converted into nitrite (NO ₂ ^- ) by the nitrifying bacteria, and in the second stage, the nitrite is converted into nitrate (NO ₃ ^- ) by the nitrifying bacteria. Denitrification reaction is a process in which denitrifying bacteria reduce nitrite nitrogen and nitrate nitrogen to gaseous nitrogen (N ₂ ) under anoxic conditions. Denitrifying bacteria are heterotrophic microorganisms, most of which belong to facultative bacteria. In anoxic state, they use oxygen in nitrate as electron acceptor and organic matter (BOD components in sewage) as electron donor to provide energy and be Oxidation stable. However, the dissolved oxygen concentration in the anaerobic tank has a great influence on the denitrification reaction, and the rapid removal of dissolved oxygen in the influent water of the anaerobic tank is conducive to the denitrification reaction and greatly improves the removal of total nitrogen in sewage.

Contents of the invention

The invention provides a device and method for removing total nitrogen in sewage. By adding a deoxygenation reactor at the front end of the anaerobic tank, the oxygen scavenger reacts with the dissolved oxygen in the influent water of the anaerobic tank and the return water of the secondary sedimentation tank to reduce the anaerobic concentration. The concentration of dissolved oxygen in the anaerobic pool and the anoxic pool can be improved, and the denitrification capacity of the anaerobic pool can be improved, thereby improving the removal of total nitrogen in the sewage.

The technical scheme adopted in the present invention is:

A sewage total nitrogen removal device, including anaerobic tank, anoxic tank, aerobic tank, secondary sedimentation tank, also includes a deoxygenation reactor, the deoxygenation reactor is located at the front end of the anoxic tank, has a mixing section, a reaction section And buffer section, equipped with sewage inlet, reflux liquid inlet, oxygen scavenger dosing port and water outlet.

Preferably, the oxygen removal reactor is a hollow closed reactor with a cylindrical upper part and an inverted frustum-shaped lower part.

Preferably, the mixing section is located at the upper end of the oxygen removal reactor, and its upper section has a large section and its lower section has a small section.

Preferably, the sewage inlet and the reflux inlet are connected to the top of the mixing section, and the oxygen scavenger dosing port is connected to the lower part of the mixing section.

Preferably, the top of the reaction section communicates with the bottom of the mixing section, and the bottom of the reaction section communicates with the lower part of the buffer section.

Preferably, the buffer section is the remaining space of the oxygen removal reactor, and the water outlet is located on the upper side of the buffer section.

A method for removing total nitrogen in sewage. The sewage influent and the reflux liquid of the secondary sedimentation tank are uniformly mixed in the mixing section, and the lower part of the mixing section contacts and reacts with an oxygen scavenger. After fully reacting in the reaction section, the liquid is released from the The outlet of the reaction section is impacted by the bottom of the buffer section to form hydraulic agitation, and finally the solution comes out through the water outlet on the upper part of the buffer section to complete the deoxygenation process of the influent in the anaerobic pool, and dissolve in the anaerobic pool The oxygen concentration is 0 mg/L ~0.2mg/L, and the denitrifying bacteria in the anaerobic tank perform nitrification reaction to remove total nitrogen under the condition of low dissolved oxygen.

Preferably, the oxygen scavenger is sodium sulfite solution.

Preferably, the residence time of the mixing section (2) is 1 s ~ 10s, the residence time of the reaction section (3) is 0.2s ~ 2s, and the residence time of the buffer section (4) is 10 s ~ 60s .

The beneficial effects of the present invention are:

1. Some studies have shown that the denitrification effect is the best when the dissolved oxygen in the anaerobic tank is 0mg/L~0.2mg/L. L, seriously affecting the denitrification effect of the anaerobic tank. Due to the low stirring intensity of the anaerobic tank, if the oxygen scavenger is directly put into the anaerobic tank, the mixing will be uneven and the reaction will be insufficient. The present invention can directly make the anaerobic tank The dissolved oxygen concentration of the influent is reduced by 0mg/L~0.2mg/L, which improves the denitrification effect of the anaerobic tank.

2. The oxygen removal reactor of the present invention is divided into three sections. The mixing section makes the sewage influent and the return liquid of the secondary sedimentation tank evenly mixed, and after mixing, it contacts with the oxygen scavenger. The inlet of the mixing section is wide and the outlet is narrow. The dosing point is close to the outlet, and the water flow directly drives the oxygen scavenger into the reaction section, and the outlet of the reaction section is blocked to form a backflow, which further promotes the reaction between the oxygen scavenger and the dissolved oxygen in the water, so that the reaction is sufficient. The entire reaction process of the present invention is completed by hydraulic power without external power, compact and small in design, and convenient to install and use.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those skilled in the art, other drawings can also be obtained according to these drawings without any creative effort.

Fig. 1 is a flowchart of a sewage total nitrogen removal device and method of the present invention.

Fig. 2 is a cross-sectional view of a sewage total nitrogen removal device according to the present invention.

Fig. 3 is a front view of a sewage total nitrogen removal device according to the present invention.

Fig. 4 is a left view of a sewage total nitrogen removal device according to the present invention.

In the figure: 1-deoxygenation reactor; 2-mixing section; 3-reaction section; 4-buffer section; 5-sewage inlet; 6-reflux liquid inlet;

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

The technical scheme adopted in the present invention is:

A sewage total nitrogen removal device, including anaerobic tank, anoxic tank, aerobic tank, secondary sedimentation tank, and also includes a deoxygenation reactor 1, the deoxygenation reactor 1 is located at the front end of the anoxic tank, and has a mixing section 2 , The reaction section 3 and the buffer section 4 are equipped with a sewage inlet 5, a reflux liquid inlet 6, an oxygen scavenger dosing port 7 and a water outlet 8.

Preferably, the oxygen removal reactor 1 is a hollow closed reactor with a cylindrical upper part and a frustoconical lower part.

Preferably, the mixing section 2 is located at the inner upper end of the oxygen removal reactor 1, and its upper part has a large cross-section and its lower part has a small cross-section.

Preferably, the sewage inlet 5 and the reflux inlet are connected to the top of the mixing section 2, and the oxygen scavenger dosing port 7 is connected to the lower part of the mixing section.

Preferably, the top of the reaction section 3 communicates with the bottom of the mixing section 2 , and the bottom of the reaction section 3 communicates with the lower part of the buffer section 4 .

Preferably, the buffer section 4 is the remaining space of the deaeration reactor 1 , and the water outlet 8 is located on the upper side of the buffer section 4 .

A method for removing total nitrogen in sewage. The sewage influent and the reflux liquid of the secondary sedimentation tank are uniformly mixed in the mixing section 2, and the lower part of the mixing section 2 is contacted and reacted with an oxygen scavenger. After fully reacting in the reaction section 3 , the liquid comes out from the outlet of the reaction section 3 and is impacted by the bottom of the buffer section 4 to form hydraulic agitation, and finally the solution comes out through the water outlet 8 on the upper part of the buffer section 4 to complete the deoxygenation of the influent of the anaerobic tank In the process, the dissolved oxygen concentration in the anaerobic tank is 0 mg/L ~0.2mg/L, and the denitrifying bacteria in the anaerobic tank perform nitrification reaction to remove total nitrogen under the condition of low dissolved oxygen.

Preferably, the oxygen scavenger is sodium sulfite solution.

Preferably, the residence time of the mixing section (2) is 1 s to 10s, the residence time of the reaction section (3) is 0.2s to 2s, and the residence time of the buffer section (4) is 10s to 60s.

Example

Sewage total nitrogen removal device, the upper part is cylindrical and the lower part is a hollow closed reactor with inverted round table shape. The inner diameter of the top section of the reactor is 50cm, the inner diameter of the bottom section of the mixing section is 10cm, and the height is 20cm; the reaction section is cylindrical and the height is 35cm; The bottom of the reaction section is 15cm away from the bottom of the reactor, and the remaining space in the reactor is a buffer section. The influent flow rate is 50m ³ /d, the dissolved oxygen concentration is 1.5mg/L, the reflux liquid flow rate is 100 m ³ /d, the dissolved oxygen concentration is 1.8mg/L, the oxygen scavenger is 30% sodium sulfite solution, and the flow rate is 270ml /h, the residence time in the mixing section is 7.5s, the residence time in the reaction section is 1.6s, the residence time in the buffer section is 55s, and the dissolved oxygen concentration in the effluent is less than 0.2 mg/L.

Claims (9)

1. a kind of sewage total nitrogen removal device, including anaerobic pond, anoxic pond, aerobic tank, secondary settling tank, which is characterized in that further include It is described except oxygen reactor (1) is located at anoxic pond front end except oxygen reactor (1), there is mixing section (2), conversion zone (3) and breeze way (4), equipped with wastewater inlet (5), phegma import (6), oxygen scavenger dosing mouth (7) and water outlet (8).

2. a kind of sewage total nitrogen removal device as described in claim 1, which is characterized in that described except oxygen reactor (1) is upper Portion is the hollow closed reactor cylindrical, lower part is reverse frustoconic.

3. a kind of sewage total nitrogen removal device as described in claim 1, which is characterized in that the mixing section (2) is located at described Except the inner upper end of oxygen reactor (1), upper part section is big, lower section is small.

4. a kind of sewage total nitrogen removal device as described in claim 1, which is characterized in that the wastewater inlet (5) and described It is connected at the top of phegma import and the mixing section (2), the oxygen scavenger dosing mouth (7) is connected with the lower part of mixing section It is logical.

5. a kind of sewage total nitrogen removal device as described in claim 1, which is characterized in that the top of the conversion zone (3) with The bottom of the mixing section (2) is connected, and the bottom of the conversion zone (3) is connected with the lower part of the breeze way (4).

6. a kind of sewage total nitrogen removal device as described in claim 1, which is characterized in that the breeze way (4) is described removes The remaining space of oxygen reactor (1), the water outlet (8) are located at the upper side of the breeze way (4).

7. a kind of sewage total nitrogen minimizing technology, which is characterized in that wastewater influent and secondary settling tank phegma are mixed in the mixing section (2) Close uniformly, in the mixing section (2) lower part and oxygen scavenger haptoreaction, in the conversion zone (3) sufficiently reaction after, liquid from Conversion zone (3) outlet comes out the impact by the breeze way (4) bottom, forms hydraulic mixing, final solution passes through institute The water outlet (8) for stating breeze way (4) top comes out, and completes the oxygen removal process of anaerobic pond water inlet, and dissolved oxygen is dense in anaerobic pond Degree is 0 mg/L ~ 0.2mg/L, and it is total that the denitrifying bacteria in anaerobic pond carries out nitration reaction removal under conditions of low dissolved oxygen Nitrogen.

8. a kind of sewage total nitrogen minimizing technology as claimed in claim 7, which is characterized in that the oxygen scavenger is that sodium sulfite is molten Liquid.

9. a kind of sewage total nitrogen minimizing technology as claimed in claim 7, which is characterized in that when the stop of the mixing section (2) Between be 1 s ~ 10s, residence time of the conversion zone (3) is 0.2 s ~ 2s, and the residence time of the breeze way (4) is 10 s ~60s。