CN110606627A - An iron-promoted magnetic loading anaerobic/anoxic activated sludge process and biofilm process coupled treatment system - Google Patents

Abstract

The invention discloses an iron-promoted magnetic loading anaerobic/anoxic activated sludge method and biofilm method coupled treatment system, which relates to the technical field of sewage treatment and includes anaerobic pools, anoxic pools, sedimentation pools, and biofilms connected in sequence. The anaerobic tank is connected with the composite iron-based accelerator dosing system, and the sedimentation tank is also connected with the magnetic species separation system. The beneficial effect of the present invention is that, compared with the conventional denitrification and dephosphorization process, not only the concentration of activated sludge in the system can be greatly increased, but also the effect of biological denitrification and dephosphorization can be enhanced; at the same time, the risk of sludge bulking can be reduced; and the process integration degree is high , good effect, reliable operation, convenient management, high load, and less land occupation.

Description

An iron-promoted magnetic loading anaerobic/anoxic activated sludge process coupled with biofilm process system

technical field

The invention relates to the technical field of sewage treatment, in particular to an iron-promoted magnetic loading anaerobic/anoxic activated sludge method and a biofilm method coupling treatment system.

Background technique

At present, water eutrophication has become a global environmental problem. A large amount of domestic sewage and industrial wastewater is discharged into the water body, resulting in a large intake of nitrogen and phosphorus-containing substances in the water body, resulting in eutrophication of the water body; the biological nitrogen and phosphorus removal process has the advantages of low cost, less secondary pollution, and mild conditions. It is widely used in wastewater nitrogen and phosphorus removal.

At present, the drainage standards of municipal and industrial sewage plants are getting higher and higher, and some local standards are higher than the "Pollutant Discharge Standards for Urban Sewage Treatment Plants" GB18918-2002 Class A Discharge Standard; and sewage plants are facing an increase in water intake at the same time, resulting in The treatment capacity is insufficient or the drainage cannot meet the standard stably. Therefore, newly-built or renovated sewage plants are faced with problems such as how to upgrade and transform or save the plant area, and achieve stable drainage standards.

Especially for low C/N sewage, traditional nitrogen and phosphorus removal technologies face insufficient carbon sources, difficult control of anaerobic environment, low denitrification efficiency, conflicts in sludge age between nitrifying bacteria and phosphorus removal bacteria, frequent sludge bulking, and land occupation. It is difficult to meet the requirements of high emission standards.

Contents of the invention

In order to solve the problems of insufficient carbon source, difficult control of anaerobic environment, low denitrification efficiency, conflicts in sludge age between nitrifying bacteria and phosphorus removing bacteria, frequent occurrence of sludge bulking, and large floor area in nitrogen and phosphorus removal, the present invention discloses An iron-promoted magnetic loading anaerobic/anoxic activated sludge process coupled with biofilm process was developed.

To achieve the above object, the present invention adopts the following technical solutions:

An iron-promoted magnetic loading anaerobic/anoxic activated sludge process coupled with biofilm process system, including sequentially connected anaerobic tank, anoxic tank, sedimentation tank, biofilm tank and post-treatment system, the anaerobic The pool is connected with the composite iron-based accelerator dosing system, and the sedimentation tank is also connected with the magnetic seed separation system.

As a further preference of the present invention, the anaerobic tank is provided with a water inlet, a sludge return inlet, a composite iron-based accelerator input inlet, an anaerobic mixed liquid outlet, and a ferromagnetic powder recovery inlet; the sewage enters through the water inlet In the anaerobic tank, the inlet for adding the composite iron-based accelerator is connected to the outlet for adding the composite iron-based accelerator of the composite iron-based accelerator; the anaerobic pool is provided with an anaerobic agitator.

As a further preference of the present invention, the anaerobic mixed solution inlet, the nitrification solution reflux inlet and the anoxic mixed solution outlet are arranged on the anoxic tank, the anaerobic mixed solution outlet of the anaerobic tank and the anaerobic mixed solution inlet on the anoxic tank connected, the anoxic pool is provided with an anoxic stirrer.

As a further preference of the present invention, an anoxic mixed solution inlet, a supernatant discharge outlet, and a sludge reflux outlet are set on the settling tank, and the sludge reflux outlet is connected to the sludge reflux inlet on the anaerobic tank. The outlet of the anoxic mixed solution is connected with the inlet of the anoxic mixed solution on the settling tank; a mud scraper and a sludge bucket are arranged at the bottom of the settling tank, and an overflow weir is set at the top of the settling tank; the settling tank is selected from a horizontal flow settling tank, a vertical It is one of flow type sedimentation tank, inclined tube (plate) sedimentation tank and radial flow type sedimentation tank.

As a further preference of the present invention, the biofilm tank is provided with a supernatant liquid discharge inlet, a nitrification liquid reflux outlet, and a nitrification mixed liquid outlet, and the nitrification liquid reflux outlet on the biofilm tank is connected with the nitrification liquid reflux inlet on the anaerobic tank. The supernatant discharge outlet of the biofilm tank is connected to the supernatant discharge inlet on the biofilm tank, and the nitrification mixed solution outlet of the biofilm tank is connected to the nitrification liquid return inlet on the anoxic tank; the biofilm tank is also provided with a bottom aeration system or Membrane aeration system, bottom aeration system or membrane aeration system adopts perforated aeration and/or microporous aeration; the biofilm pool is biological aerated filter (BAF), biological contact oxidation tank, moving bed biofilm At least one of reactor (MBBR), membrane aerobic biofilm reactor (MABR).

As a further preference of the present invention, the post-treatment system is used for subsequent treatment after sewage treatment, including at least one of a mud-water separation and sedimentation device, a filter device, a deep denitrification and dephosphorization device, and a disinfection device; A nitrification mixture inlet and an effluent outlet are provided, and the nitrification mixture outlet on the biofilm tank is connected with the nitrification mixture inlet on the post-treatment system.

As a further preference of the present invention, the magnetic seed separation system includes a high shear machine and a magnetic separator. The magnetic seed separation system is also provided with an inlet for excess sludge, an outlet for reclaiming ferromagnetic powder, and an outlet for sludge discharge. The reclaimed iron The magnetic powder outlet is connected with the recovered ferromagnetic powder inlet on the anaerobic tank, and the residual sludge inlet on the magnetic seed separation system is connected with the sludge return outlet on the sedimentation tank.

As a further preference of the present invention, the activated sludge concentration in the anaerobic tank and the anoxic tank is 8000-20000 mg/L.

As a further preference of the present invention, the composite iron-based promoter is selected from the group consisting of ferric iron tetroxide powder (Fe ₃ O ₄ ), Fe ⁰ , FeSO ₄ , FeCl ₂ , Fe ₂ (SO ₄ ) ₃ , FeCl ₃ , polymeric sulfuric acid One or more of iron (PFS), polyaluminum ferric chloride (PAFC), polyaluminum ferric silicate (PSAF).

As a further preference of the present invention, the composite iron-based material contains ferric oxide powder, and the particle size of ferric oxide powder to be added is 40-200 μm ^; _4. FeCl ₂ , Fe ₂ (SO ₄ ) ₃ , FeCl ₃ , PFS, PAFC, PSAF dosing and proportioning are adjusted accordingly to meet the requirements of stable and up-to-standard discharge of each index.

In the present invention, each unit function is as follows:

The front stage of the system process is based on the composite iron-based accelerator to strengthen the anaerobic/anoxic activated sludge method. By adding the composite iron-based accelerator to the anaerobic tank, the specific gravity and settling performance of the sludge floc are greatly improved, and the system is improved. Activated sludge concentration; under the condition of alternate operation of anaerobic/anoxic environment, it is easy to enrich denitrifying and dephosphorizing bacteria (DPB) to achieve efficient denitrification and dephosphorization of low C/N wastewater; the latter part of the system process uses biological Membrane technology is the core, and nitrifying bacteria are attached to the carrier to grow and enrich, which strengthens the nitrification and simultaneous nitrification and denitrification (SND) denitrification functions of the system, and there is no risk of sludge bulking.

In the anaerobic tank, the influent is mixed with the mixed solution, recovered ferromagnetic powder, return sludge, and composite iron-based promoters. Under the action of anaerobic bacteria, the macromolecular organic matter is converted into small molecular volatile organic matter. At the same time, Phosphorus accumulating bacteria hydrolyze intracellular polyphosphate into orthophosphate.

In the anoxic pool, the nitrification solution flows back into the anoxic pool to supplement nitrate for the anoxic pool; under the condition of insufficient carbon source, the denitrifying phosphorus-accumulating bacteria in the anoxic pool can absorb phosphorus excessively on the one hand, and also on the other hand It can remove nitrate, realize "one carbon, two uses", and enhance the effect of nitrogen and phosphorus removal in the system.

In the sedimentation tank, the sludge is separated from water. Part of the separated sludge containing ferromagnetic powder flows back to the anaerobic tank, and the other part enters the magnetic seed separation system; while the separated supernatant flows into the biofilm tank.

In the magnetic separation system, the sludge containing ferromagnetic powder is successively peeled off by the high shear machine to separate the ferromagnetic powder and the remaining sludge, and then the ferromagnetic powder and the remaining sludge are separated by the magnetic separator, and the separated ferromagnetic powder is refluxed to the anaerobic tank, and the separated residual sludge is discharged out of the system.

In the biofilm pool, pollutants such as ammonia nitrogen in the supernatant are converted into nitrate or nitrite under the action of nitrifying bacteria attached to the carrier to provide a substrate for anoxic denitrification.

In the post-treatment equipment, the suspended solids and total phosphorus in the effluent of the aerobic biofilm tank are removed, so that the effluent can be discharged up to the standard.

In the present invention, the reflux of nitrifying liquid can supplement nitrate for the anoxic tank, and provide matrix conditions for denitrification and phosphorus removal, and the sludge reflux can return the activated sludge of ferromagnetic powder to the anaerobic tank to maintain anaerobic/anoxic High sludge concentration in the activated sludge system; at the same time control the concentration of dissolved oxygen and nitrate in the anaerobic tank to provide good conditions for the release of phosphorus in the anaerobic tank.

The beneficial effect of the present invention is that, compared with conventional denitrification and dephosphorization technologies, it has:

1. Enhance phosphorus removal effect

11) Denitrification and phosphorus removal

Under the condition _of alternate operation of anaerobic ^/ anoxic environment, it is easy to enrich the denitrifying and dephosphorizing bacteria (DPB) which has both denitrification and phosphorus removal. Phosphorus and denitrification process; greatly reducing the demand for carbon sources, achieving double savings in energy and resources; denitrification and phosphorus removal can save about 50% of COD, save about 30% of oxygen, and reduce the amount of remaining sludge by about 50%.

12) Auxiliary chemical phosphorus removal

Dosing composite iron promoters into the anaerobic tank, such as Fe ⁰ , Fe ²⁺ , Fe ³⁺ , can react directly or indirectly with phosphate.

Taking Fe ²⁺ as an example, Fe ²⁺ reacts with phosphate in the anaerobic tank to form insoluble Fe ₃ (PO ₄ ) ₂ , and the reaction formula (1) is as follows:

3Fe ²⁺ +2PO ₄ ^3- →Fe ₃ (PO ₄ ) ₂ (s)(1)

The generated Fe ₃ (PO ₄ ) ₂ precipitates are attached to the sludge flocs through sludge flocculation; the Fe ₃ (PO ₄ ) ₂ precipitates are discharged out of the system through the discharge of excess sludge, which improves the phosphorus removal efficiency.

2. Strengthen the denitrification effect

21) There is a contradiction in sludge age between the phosphorus-removing bacteria and the nitrifying bacteria in the traditional nitrogen and phosphorus removal process; the denitrifying phosphorus-accumulating bacteria are enriched through the alternate operation of anaerobic/anoxic environment; its main function is to remove COD and denitrify phosphorus; By adding biofilm carriers into the aerobic tank, a good living environment for nitrifying bacteria is provided to achieve efficient denitrification; The system is cultivated separately to form a double sludge system; each functional bacteria can grow in their own suitable environment, which is conducive to the stable and efficient nitrogen and phosphorus removal of the system.

22) Adding composite iron-based promoters and recovering ferromagnetic powder can provide a large attachment area for the growth and enrichment of anaerobic/anoxic microorganisms, and provide a good living environment for anaerobic/anoxic microorganisms; Process is the core, because the diffusion of oxygen inside the biofilm is limited, the surface of the biofilm is in an aerobic state, the inner layer is in anoxic or even anaerobic state, or the interior is in an aerobic state and the surface is in an anoxic state, which has good nitrification And a certain synchronous nitrification and denitrification function.

23) Long-term dosing of composite iron-based accelerators, such as Fe ⁰ , Fe ²⁺ , and Fe ³⁺ , in the sludge system can be used as electron donors or acceptors to participate in the oxidation or reduction of nitrogen.

Taking Fe ²⁺ as an example, under the action of microorganisms, Fe ²⁺ can be used as an electron donor to reduce nitrate or nitrite to nitrogen, that is, to produce ferrous denitrification phenomenon to strengthen the removal of total nitrogen in the system. Ferrous The chemical reaction formula of denitrification is shown in (2)~(3):

2NO ₃ ^- +10Fe ²⁺ +24H ₂ O→10Fe(OH) ₃ +N ₂ +18H ⁺ (2)

2NO ₂ ^- +6Fe ²⁺ +14H ₂ O→6Fe(OH) ₃ +N ₂ +10H ⁺ (3)

The electron donor takes Fe ²⁺ as an example, and the n(Fe ²⁺ )/n(NO ₃ ^- ) consumed by the iron-type denitrification process is 5:1 or n(Fe ²⁺ )/n(NO ₂ ^- ) is 3 : 1.

3. Enhance carbon removal effect

31) Long-term dosing of composite iron-based accelerators, such as Fe ⁰ , Fe ²⁺ , and Fe ³⁺ , in the sludge system can directly or indirectly promote the decomposition and synthesis of organic matter by microorganisms, and at the same time strengthen the sludge floc Flocculation effect on colloid or suspended matter in influent.

Taking Fe ²⁺ as an example, the hydrolyzed product of Fe ²⁺ can coagulate the organic colloid or suspended matter in the influent through flocculation, net capture and sweeping, adsorption and bridging, etc., and strengthen the removal of organic matter by the system.

32) Adding composite iron-based promoters and recovering ferromagnetic powder can form a higher sludge concentration; it is beneficial to increase the concentration of hydrolytic acidification bacteria and extracellular enzymes, and promote the full transformation of colloids and suspended organic matter in the influent It is used efficiently for dissolved organic matter; at the same time, it can convert some organic matter that is difficult to aerobic biodegradation into biodegradable organic matter.

4. Shorten the mud-water separation time

Conventional denitrification and phosphorus removal process, the specific gravity of the sludge is low, the surface load of the sedimentation tank is usually 0.6-1.0m ³ /(m ² h), and the activity can be increased by adding composite iron-based accelerators and recycling ferromagnetic powder The specific gravity of the sludge makes the activated sludge floc structure compact, and the surface load of the sedimentation tank can reach 3.0-8.0m ³ /(m ² ·h), which greatly shortens the separation time of sludge and water.

5. Strengthen the system against impact load

51) The anaerobic/anoxic activated sludge system is added with composite iron-based accelerators and recycled ferromagnetic powder, which greatly increases the proportion of sludge flocs and greatly improves the sedimentation performance of sludge flocs. The activated sludge concentration of the conventional activated sludge method is 2500-4000mg/L; after adding ferromagnetic powder, the activated sludge concentration can reach 8000-20000mg/L, and the processing capacity is increased by 3-5 times.

52) After the conventional denitrification and phosphorus removal process is impacted, nitrifying bacteria are easily inhibited, resulting in a gradual decrease in the proportion of nitrifying bacteria, making the effluent unable to meet the standard stably; the biofilm process fixes the nitrifying bacteria on the carrier in the form of attachment by adding the carrier , significantly enhancing the resistance to short-term shocks.

6. Less sludge output, avoiding sludge bulking

61) The anaerobic/anoxic activated sludge system is added with composite iron-based accelerators and recycled ferromagnetic powder, which greatly increases the proportion of sludge flocs, greatly improves the sedimentation performance of sludge flocs, and sludge is not prone to sludge bulking At the same time, due to the existence of ferromagnetic powder, the system can produce a magnetic field effect, balance the growth and decline of microorganisms in the activated sludge, and effectively inhibit the sludge bulking. At the same time, the anaerobic/anoxic setting strengthens the denitrification and phosphorus removal, realizes "one carbon for two purposes", and reduces the sludge production of the anaerobic/anoxic activated sludge system.

62) In the biofilm process, microorganisms exist on the surface of the carrier in the form of attachment, and there is no risk of sludge bulking; at the same time, the biofilm sludge yield is lower than that of the activated sludge process, which reduces the sludge production of the aerobic process.

Description of drawings

Fig. 1 is a structural representation of the present invention;

Fig. 2 is the structural representation of embodiment;

Among them, 1-water inlet pipe; 2-anaerobic tank; 3-anaerobic agitator; 4-anoxic tank; 5-anoxic agitator; 6-sludge return pipe; 7-sludge return pump; 8-high Shearing machine; 9-magnetic separator; 10-recovery ferromagnetic powder replenishment pipe; 11-excess sludge discharge pipe; 12-compound iron-based accelerator dosing system; 13-sedimentation tank inlet pipe; 14-sedimentation tank diversion 15-sedimentation tank; 16-sludge scraper of sedimentation tank; 17-sludge hopper of sedimentation tank; 18-sedimentation tank fender; 19-settling tank collection channel; 20-aerobic pure membrane MBBR tank; 21-suspension Carrier; 22-Aeration system; 23-Membrane MBBR outlet pipe; 24-Blower; 25-Nitrating liquid return pump; 26-Quick mixing tank; 27-PAC dosing system; pool; 30-PAM dosing system; 31-flocculation agitator; 32-flocculation guide tube; 33-high efficiency sedimentation tank; 34-high efficiency sedimentation tank sludge bucket; Pool mud pump; 37-high-efficiency sedimentation tank return pipe; 38-high-efficiency sedimentation tank mud discharge pipe; 39-high-efficiency sedimentation tank partition; 40-high-efficiency sedimentation tank inclined pipe; Pool outlet pipe; 43-rotary filter; 44-rotary filter outlet.

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 of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Example 1

The invention discloses an iron-promoted magnetic loading anaerobic/anoxic activated sludge method and a biofilm method coupled treatment system, as shown in Figure 1, including an anaerobic pool, anoxic pool, sedimentation pool, and biofilm pool connected in sequence And the post-treatment system, the above-mentioned anaerobic pool is connected with the composite iron-based accelerator dosing system, and the above-mentioned sedimentation tank is also connected with the magnetic species separation system.

In particular, the above-mentioned anaerobic tank is provided with a water inlet, a sludge return inlet, a composite iron-based accelerator input inlet, an anaerobic mixed liquid outlet, and an inlet for recovering ferromagnetic powder; the sewage enters the anaerobic tank through the water inlet, and the composite The inlet for adding iron-based accelerators is connected to the outlet for adding composite iron-based accelerators of the compound iron-based accelerator dosing system; an anaerobic agitator is provided in the above-mentioned anaerobic pool.

In particular, the above-mentioned anoxic pool is provided with an anaerobic mixed liquid inlet, a nitrifying liquid return inlet, and an anoxic mixed liquid outlet, and the anaerobic mixed liquid outlet of the anaerobic pool is connected with the anaerobic mixed liquid inlet on the anoxic pool. An anoxic stirrer is provided in the pool.

In particular, the above-mentioned sedimentation tank is provided with an anoxic mixed liquid inlet, a supernatant liquid discharge outlet, and a sludge return outlet. The sludge return outlet on the above-mentioned sedimentation tank is connected with the sludge return inlet on the anaerobic tank. The outlet of the liquid is connected to the inlet of the anoxic mixed solution on the sedimentation tank; a mud scraper and a sludge bucket are arranged at the bottom of the above sedimentation tank, and an overflow weir is arranged at the upper part of the sedimentation tank.

The above-mentioned sedimentation tank adopts an advection sedimentation tank.

In particular, the above-mentioned biofilm tank is provided with a supernatant discharge inlet, a nitrification liquid return outlet, and a nitrification mixed solution outlet. The nitrification liquid return outlet on the biofilm tank is connected to the nitrification liquid return inlet on the anaerobic tank. The outlet is connected to the discharge inlet of the supernatant on the biofilm tank, and the outlet of the nitrification mixed solution of the biofilm tank is connected to the return inlet of the nitrification liquid on the anoxic tank; the above biofilm tank is also equipped with a bottom aeration system, which can also be added according to actual needs Agitator, bottom aeration system perforated aeration aeration.

The biofilm pool mentioned above is a biological aerated filter (BAF).

In particular, the above-mentioned post-treatment system is used for subsequent treatment after sewage treatment, including a mud-water separation and sedimentation device; the post-treatment system is also provided with a nitrification mixed solution inlet and an outlet, and the nitrification mixed solution outlet on the biofilm tank is connected to the post-treatment system. The nitrification mixture inlet is connected.

In particular, the above-mentioned magnetic seed separation system includes a high shear machine and a magnetic separator. The magnetic seed separation system is also provided with an inlet for excess sludge, an outlet for reclaiming ferromagnetic powder, and an outlet for sludge discharge. The outlet for reclaiming ferromagnetic powder is connected to anaerobic The inlet of recovered ferromagnetic powder on the tank is connected, and the inlet of excess sludge on the magnetic seed separation system is connected with the sludge return outlet on the sedimentation tank. The high shear machine strips the ferromagnetic powder and the remaining sludge from the ferromagnetic powder-containing sludge collected at the bottom of the sedimentation tank; the magnetic separator separates the ferromagnetic powder from the remaining sludge; and then returns the recovered ferromagnetic powder to the exhaust Oxygen tank, excess sludge discharge system.

Particularly, the activated sludge concentration in the above-mentioned anaerobic tank and the above-mentioned anoxic tank is 8000-20000mg/L.

In particular, the above-mentioned composite iron-based promoters are selected from ferric oxide powder (Fe ₃ O ₄ ) and FeSO ₄ ; the particle size of ferric oxide powder added is 50 μm; ₄ Dosing and proportioning can be adjusted to meet the requirements of stable and up-to-standard discharge of various indicators.

Example 2

The difference from Example 1 is:

The above-mentioned sedimentation tank is a vertical flow sedimentation tank.

The above-mentioned biofilm tank is also equipped with a bottom aeration system, and an agitator can also be added according to actual needs. The bottom aeration system adopts perforated "aeration + microporous" combined aeration.

The biofilm pool mentioned above is a biological contact oxidation pool.

The above-mentioned post-treatment system is used for subsequent treatment after sewage treatment, including a mud-water separation and sedimentation device and a filtration device.

The above-mentioned composite iron-based accelerator is selected from ferric oxide powder (Fe ₃ O ₄ ); and the particle size of the added ferric oxide powder is 100 μm.

Example 3

The difference from Example 1 is:

The above-mentioned sedimentation tank is selected as inclined tube (plate) sedimentation tank.

The above-mentioned biofilm pool is also equipped with a membrane aeration system, and an agitator can also be added according to actual needs. The membrane aeration system adopts microporous aeration.

The biofilm pool mentioned above is a biological aerated filter (BAF) and a membrane aerobic biofilm reactor (MABR).

The above-mentioned post-treatment system is used for subsequent treatment after sewage treatment, including a filter device, a deep denitrification and dephosphorization device and a disinfection device.

The above-mentioned composite iron-based promoters are selected from ferric oxide powder (Fe ₃ O ₄ ), FeCl ₃ , and polyferric sulfate (PFS); the particle size of ferric oxide powder added is 200 μm; Different, FeCl ₃ , PFS dosing and proportioning can be adjusted to meet the requirements of each indicator to meet the emission standards stably.

Example

The domestic sewage in a village is treated by a sewage treatment system that combines the anaerobic/anoxic activated sludge method coupled with the biofilm method, as shown in Figure 2, including anaerobic pools connected in sequence 2, anoxic Pool 4, sedimentation tank 15, aerobic pure membrane MBBR tank 20, fast mixing tank 26, flocculation tank 29, high-efficiency sedimentation tank 33 and rotary filter tank 43, anaerobic tank 2 is connected with composite iron-based accelerator dosing system 12, The sedimentation tank 15 is also connected with the high shear machine 8 and the magnetic separator 9 .

The anaerobic tank 2 is provided with a water inlet pipe 1 , the anaerobic mixer 3 is located inside the anaerobic tank 2 , and the compound iron-based accelerator dosing system 12 is installed above the anaerobic tank 2 .

Anoxic agitator 5 is installed in anoxic pool 4 , high shear machine 8 and magnetic separator 9 are installed above anoxic pool 4 , and anoxic pool 4 is also connected with sludge return pipe 6 .

The sedimentation tank 15 is provided with a sedimentation tank inlet pipe 13, a sedimentation tank guide tube 14, a sedimentation tank mud scraper 16, a sedimentation tank sludge bucket 17, a sedimentation tank fender 18, and a sedimentation tank collection channel 19; the bottom of the sedimentation tank 15 The sedimentation tank sludge bucket 17 is set, and the sedimentation tank sludge scraper 16 is also installed on the sedimentation tank sludge bucket 17, and the sedimentation tank diversion tube 14 is placed in the middle of the sedimentation tank 15; the mixed solution of the anoxic tank 4 passes through the sedimentation tank inlet pipe 13 communicates with the sedimentation tank guide tube 14, and the upper part of the sedimentation tank guide tube 14 is also provided with two sets of sedimentation tank fenders 18 and sedimentation tank collecting channel 19 connected; Connected; the pipeline of the sludge return pump 7 is connected to the bottom of the sludge bucket 17 of the sedimentation tank, and the outlet pipeline is divided into two routes, which are regulated by the opening of the valve, one of which is connected to the anaerobic tank 2, and the other is connected to the high shear machine 8 The high shear machine 8 is connected with the magnetic separator 9, and the ferromagnetic powder separated by the magnetic separator 9 flows into the anaerobic tank 2 through the reclaimed ferromagnetic powder replenishment pipe 10, and the separated excess sludge passes through the excess sludge discharge pipe 11 drain system.

A suspension carrier 21 is added to the pure membrane MBBR tank, and an aeration system 22 is installed at the bottom; the suspension carrier 21 is a columnar suspension carrier made of HDPE with a diameter of 25 mm; the aeration system 22 uses a combination of "perforation + micropore" aeration.

The aeration system 22 is connected with the blower 24, and the aerobic pure membrane MBBR tank 20 is connected with the anoxic tank 4 through the nitrifying liquid return pump 25;

A PAC dosing system 27 and a quick mixing agitator 28 are arranged in the quick mixing tank 26 .

The flocculation tank 29 is provided with a PAM dosing system 30 , a flocculation agitator 31 , and a flocculation guide tube 32 ; the flocculation guide tube 32 is placed in the middle of the flocculation tank 29 .

High-efficiency sedimentation tank 33 is equipped with high-efficiency sedimentation tank sludge hopper 34, high-efficiency sedimentation tank scraper 35, high-efficiency sedimentation tank separator 39, high-efficiency sedimentation tank inclined pipe 40, high-efficiency sedimentation tank collection channel 41; the bottom of high-efficiency sedimentation tank 33 is set The high-efficiency sedimentation tank sludge bucket 34, the high-efficiency sedimentation tank sludge scraper 35 is set above the high-efficiency sedimentation tank sludge bucket 34, and the high-efficiency sedimentation tank inclined pipe 40 is located in the middle and upper part of the high-efficiency sedimentation tank 33; the material of the high-efficiency sedimentation tank inclined pipe 40 is PP, the pore diameter is The oblique length is 1000mm; the separator 39 of the high-efficiency sedimentation tank is connected with the inclined pipe 40 of the high-efficiency sedimentation tank; the water collection channel 41 of the high-efficiency sedimentation tank is placed directly above the inclined pipe 40 of the high-efficiency sedimentation tank, and the outlet pipe 42 of the high-efficiency sedimentation tank is connected with the water collection channel 41 of the high-efficiency sedimentation tank The sludge bucket 34 of the high-efficiency sedimentation tank is connected with the sludge discharge pump 36 of the high-efficiency sedimentation tank. Mud pipe 38 links to each other;

The rotary disc filter 43 is connected with the high-efficiency sedimentation tank 33 through the outlet pipe 42 of the high-efficiency sedimentation tank, and the filtered water is discharged from the system through the outlet pipe 44 of the rotary disc filter.

A domestic sewage treatment project in a village and town has a designed water volume of 500m ³ /d. Due to limited land occupation and high requirements for effluent water quality, composite iron-based accelerators are used to strengthen the anaerobic/anoxic activated sludge process and biofilm process to couple sewage The treatment system is used as an emergency facility, and the effluent after treatment is required to meet the requirements of quasi-IV water effluent. The specific data are shown in the table below:

Table 1 Average influent and effluent water quality of a domestic sewage treatment project in a village

Note: The data are the average influent and effluent water quality of the system.

The system can effectively remove various pollutants in the water, and the effluent quality is stable; it is better than the quasi-IV discharge limit requirements; the pollutants are greatly reduced and the impact on the environment is reduced; among them, the CODcr emission reduction is 73.73 tons/year, BOD ₅ emissions are reduced by 37.94 tons/year, ammonia nitrogen emissions are reduced by 7.98 tons/year, total nitrogen emissions are reduced by 8.05 tons/year, total phosphorus emissions are reduced by 1.18 tons/year, and SS emissions are reduced by 41.79 tons/year.

Compared with the conventional anaerobic reactor, the front stage of the system process of the present invention takes the compound iron-based accelerator to strengthen the anaerobic/anoxic activated sludge method as the core, and by adding the composite iron-based accelerator to the anaerobic tank 2, the sewage The specific gravity and settling performance of mud flocs have been greatly improved, which increases the concentration of activated sludge in the system; under the condition of alternating anaerobic/anoxic environment, it is easy to enrich denitrifying phosphorus removal bacteria (DPB) and achieve low C/N Efficient denitrification and phosphorus removal of wastewater; the latter part of the system process is based on biofilm technology, and nitrifying bacteria grow on the surface of the carrier and are enriched, which strengthens the denitrification function of the system and has no risk of sludge bulking; it has process integration It has the advantages of high precision, good effect, reliable operation, convenient management, and less land occupation. In addition, the process equipment can be controlled by linkage to realize unattended operation.

Of course, the above descriptions are not intended to limit the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or replacements made by those skilled in the art within the scope of the present invention shall also belong to the present invention. protection scope of the invention.

Claims (9)

1. An iron-promoted magnetic loading anaerobic/anoxic activated sludge method and biofilm method coupling treatment system, is characterized in that, comprises anaerobic pond, anoxic pond, sedimentation pond, biofilm pond and post-treatment that are sequentially connected system, the anaerobic tank is connected with the composite iron-based accelerator dosing system, and the sedimentation tank is also connected with the magnetic species separation system. 2. A kind of iron-promoted magnetic loading anaerobic/anoxic activated sludge method and biofilm method coupling treatment system as claimed in claim 1, it is characterized in that, the described anaerobic tank is provided with water inlet, sludge return inlet , composite iron-based accelerator input inlet, anaerobic mixed solution outlet and recycled ferromagnetic powder inlet; sewage enters the anaerobic tank through the water inlet, and the composite iron-based accelerator input inlet and composite iron-based accelerator dosing system The composite iron-based accelerator is connected to the outlet, and the composite iron-based accelerator is added to the anaerobic pool; the anaerobic pool is provided with an anaerobic stirrer. 3. a kind of iron-promoted magnetic loading anaerobic/anoxic activated sludge method and biofilm method coupling treatment system as claimed in claim 1, is characterized in that, described anoxic tank is provided with anaerobic mixed solution inlet, nitrifying liquid The backflow inlet and the outlet of the anoxic mixed solution, the outlet of the anaerobic mixed solution of the anaerobic tank is connected with the inlet of the anaerobic mixed solution on the anoxic tank, and an anoxic agitator is arranged in the anoxic tank. 4. A kind of iron-promoted magnetic loading anaerobic/anoxic activated sludge method and biofilm method coupled treatment system as claimed in claim 1, characterized in that, anoxic mixed solution inlet and supernatant discharge are set on the settling tank outlet, sludge return outlet, the sludge return outlet is connected to the sludge return inlet on the anaerobic tank, the anoxic mixed solution inlet of the sedimentation tank is connected to the anoxic mixed solution outlet of the anoxic tank; the bottom of the sedimentation tank A mud scraper and a sludge bucket are set, and an overflow weir is set on the upper part; the settling tank is selected from one of a horizontal flow settling tank, a vertical flow settling tank, an inclined tube (plate) settling tank, and a radial flow settling tank . 5. a kind of iron-promoted magnetic loading anaerobic/anoxic activated sludge method and biofilm method coupling treatment system as claimed in claim 1, is characterized in that, supernatant liquid discharge inlet, nitrification liquid reflux are set on the described biofilm tank Outlet, nitrification mixture outlet, the nitrification liquid return outlet on the biofilm tank is connected with the nitrification liquid return inlet on the anaerobic tank, the supernatant discharge outlet on the sedimentation tank is connected with the supernatant discharge inlet on the biofilm tank, and the biofilm tank The nitrification mixed liquid outlet is connected with the nitrification liquid reflux inlet on the anoxic tank; the biofilm tank is also provided with a bottom aeration system or a membrane aeration system, and the bottom aeration system adopts perforated aeration and/or microporous aeration; The biofilm tank is at least one of a biological aerated filter (BAF), a biological contact oxidation tank, a moving bed biofilm reactor (MBBR), and a membrane aerobic biofilm reactor (MABR). 6. A kind of iron-promoted magnetic loading anaerobic/anoxic activated sludge method and biofilm method coupling treatment system as claimed in claim 1, is characterized in that, described aftertreatment system is used for the follow-up treatment after sewage treatment, comprises At least one of mud-water separation and sedimentation device, filtration device, deep denitrification and dephosphorization device, and disinfection device; the post-treatment system is also provided with a nitrification mixed solution inlet and an effluent outlet, and the nitrification mixed solution inlet and biofilm on the post-treatment system The nitrification mixture outlet on the pool is connected. 7. A kind of iron-promoted magnetic loading anaerobic/anoxic activated sludge method and biofilm method coupling treatment system as claimed in claim 1, is characterized in that, described magnetic kind separation system comprises high shear machine and magnetic separator, The magnetic seed separation system is also provided with an inlet for excess sludge, an outlet for reclaiming ferromagnetic powder and a sludge discharge outlet. The outlet for reclaiming ferromagnetic powder is connected to the inlet for reclaiming ferromagnetic powder on the anaerobic tank. The sludge inlet is connected with the sludge return outlet on the sedimentation tank. 8. A kind of iron promotion magnetic loading anaerobic/anoxic activated sludge method and biofilm method coupling treatment system as claimed in claim 3, is characterized in that, the activated sewage in described anaerobic pond, described anoxic pond The mud concentration is 8000-20000mg/L. 9. a kind of iron as claimed in claim 2 promotes magnetic loading anaerobic/anoxic activated sludge method and biofilm method coupling treatment system, it is characterized in that, described composite iron series promotes thing and is selected from ferric iron tetroxide powder ( Fe ₃ O ₄ ), Fe ⁰ , FeSO ₄ , FeCl ₂ , Fe ₂ (SO ₄ ) ₃ , FeCl ₃ , Polyferric Sulfate (PFS), Polyaluminum Ferric Chloride (PAFC), Polyaluminum Ferric Silicate (PSAF) one or more of.