Sewage electrochemical coupling microbiological treatment method and device

Abstract

The invention discloses a sewage electrochemical coupling microbiological treatment method and device, and belongs to the technical field of sewage treatment. Sewage is pumped into an anaerobic zone, and the sludge reflux ratio is adjusted in time by calculating the internal carbon source conversion rate, the assimilation ammonia nitrogen removal contribution rate and the like; effluent overflows to a first anoxic zone and a second anoxic zone for phosphorus and nitrogen removal through denitrification; effluent enters the aerobic zone and the micro-aerobic zone, and trace nitrogen and phosphorus are reduced under the action of electrochemical reaction and microorganisms; effluent enters a settling zone, and mud-water separation is carried out. The microbiological treatment device comprises an anaerobic zone, a first anoxic zone, a second anoxic zone, an aerobic zone, a micro-aerobic zone and a settling zone which are sequentially arranged, and the micro-aerobic zone is provided with a DO online detector 2, an electrochemical reaction device and an iron ion online detector. An electrochemical strengthening mechanism is coupled, iron ions promote metabolism of microorganisms, enrichment and directional regulation of dominant functional bacteria are achieved, the sewage treatment cost can be remarkably reduced, and the treatment efficiency can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment, and in particular to a sewage electrochemically coupled microbial treatment method and device. Background Art

[0002] With the acceleration of the global industrialization process and the continuous improvement of urbanization levels, sewage discharge has become an increasingly serious environmental problem. In this process, complex pollutants formed by industrial wastewater, domestic sewage and agricultural irrigation discharge have had a significant impact on the aquatic ecosystem. Although traditional sewage treatment technologies, such as activated sludge, biofilm and anaerobic digestion, have achieved good treatment effects in some cases, their efficiency and stability are insufficient when faced with high-concentration, difficult-to-degrade organic matter and toxic and harmful pollutants. Several limitations of these existing technologies make it urgent to explore more efficient, economical and environmentally friendly alternatives in the treatment of industrial wastewater, sudden pollution incidents and environmental restoration.

[0003] In traditional sewage treatment processes, microorganisms are widely used to degrade organic pollutants and remove nitrogen and phosphorus. Microbial treatment systems rely on the collaboration of multiple microbial communities, using their metabolism to convert organic matter in sewage into harmless substances and promote nitrogen nitrification and denitrification. However, microorganisms are extremely sensitive to external environmental conditions. For example, factors such as water temperature, pH value, and dissolved oxygen concentration can affect their activity and degradation efficiency. This makes microbial treatment powerless when dealing with high-concentration and complex pollutants. In addition, for certain specific persistent organic pollutants and heavy metal pollutants, traditional microbial systems often face the dilemma of inhibiting growth and reducing activity.

[0004] In contrast, electrochemical technology, with its efficient reaction rate and good controllability, has gradually shown its potential for wide application in the field of sewage treatment. Electrochemical sewage treatment mainly generates strong oxidizing substances such as hydroxyl radicals and active chlorine through the redox reaction of electrodes. These active substances have extremely strong degradation ability and can effectively degrade various organic pollutants, heavy metal ions and harmful microorganisms in water. Electrochemical technology not only has a fast reaction speed and high removal efficiency, but also can realize real-time monitoring and online operation of water quality, and has good application prospects. Despite this, there are many problems with a single electrochemical treatment method. For example, electrode materials are prone to corrosion, energy consumption is high, and reaction conditions are not ideal for the treatment of certain complex pollutants.

[0005] The existing sewage treatment technology has high energy consumption, large floor space and poor effluent quality. Summary of the invention

[0006] The purpose of the present invention is to overcome the above technical deficiencies and provide a sewage electrochemical coupled microbial treatment method and device to solve the technical problems of high energy consumption, large footprint and poor effluent quality in the prior art sewage treatment.

[0007] In order to achieve the above technical objectives, the technical solution of the present invention provides a sewage electrochemical coupled microbial treatment method, comprising the following steps:

[0008] S1. Pump the sewage into the anaerobic zone. Sugar source accumulating microorganisms convert organic matter into internal carbon, ammonia assimilation bacteria convert ammonia nitrogen into internal nitrogen source, and phosphorus-releasing bacteria release a large amount of phosphoric acid while taking organic matter as internal carbon source. Calculate the internal carbon source conversion rate, the contribution rate of ammonia nitrogen removal by assimilation, and the contribution rate of denitrification to adjust the frequency of the sludge return pump;

[0009] S2, pumping the effluent from the anaerobic zone into the first anoxic zone, wherein the ammonia assimilation bacteria further convert the ammonia nitrogen into an internal nitrogen source, and the denitrifying phosphorus-accumulating bacteria absorb the extracellular phosphate and reduce the nitrate nitrogen to nitrogen gas, thereby achieving simultaneous denitrification and phosphorus removal, calculating the denitrification contribution rate of the denitrification and phosphorus removal process, and adjusting the frequency of the internal reflux pump;

[0010] S3, pump the effluent from the first anoxic zone into the second anoxic zone, and then into the aerobic zone for nitrification and ammonia nitrogen removal reaction. At the same time, the phosphate of phosphorus-absorbing bacteria is converted into intracellular substances, and the contribution rate of nitrification in the aerobic zone is calculated to maintain the DO value within the range of 0.8-1.5mg / L;

[0011] S4, the effluent from the aerobic zone enters the micro-aerobic zone, where the trace nitrogen and phosphorus are reduced under the action of electrochemical reaction and microorganisms, maintaining the DO value within the range of 0.2-0.6 mg / L and the iron ion concentration within the range of 10-30 mg / L;

[0012] S5. The water from the micro-oxygen zone enters the sedimentation zone for mud and water separation.

[0013] A sewage electrochemical coupled microbial treatment device as described above comprises an anaerobic zone, a first anoxic zone, a second anoxic zone, an aerobic zone, a microaerobic zone and a precipitation zone arranged in sequence, wherein the microaerobic zone is provided with a DO online detector 2, an electrochemical reaction device and an iron ion online detector.

[0014] Preferably, a sludge return pump is provided between the anaerobic zone and the sedimentation zone, and an internal return pump is provided between the first anoxic zone and the micro-aerobic zone.

[0015] Preferably, a microporous aeration hose 1 , a fluidized bed filler, an aeration valve 1 , an aeration flowmeter 1 and a blower 1 are provided in the aerobic zone.

[0016] Preferably, a DO online detector 1 is provided in the aerobic zone. When the DO value is greater than 1.5 mg / L, the opening of the aeration valve 1 is reduced by 5% until the DO value is within the range of 0.8-1.5 mg / L, and the opening is ensured to remain unchanged; when the opening of the aeration valve 1 is 5%, and the DO value still cannot be within the range of 0.8-1.5 mg / L, the blower is reduced by 1 Hz until the DO value is within the range of 0.8-1.5 mg / L.

[0017] Preferably, the service area of ​​the microporous aeration hose 1 is 0.3m 2 / m, ventilation volume 0.5m 3 / (h·m), oxygen utilization rate is 30-50%.

[0018] Preferably, a microporous aeration hose 2, an electrolytic cell, a pulsed DC power supply, an aeration valve 2, an aeration flowmeter 2 and a blower 2 are provided in the micro-oxygen zone.

[0019] Preferably, when the DO value measured by the DO online detector 2 is greater than 0.6 mg / L, the opening of the aeration valve 2 is reduced by 5% until the DO value is between 0.2 and 0.6 mg / L, ensuring that the opening remains unchanged; when the opening of the aeration valve 2 is 5%, and the DO value still cannot be between 0.2 and 0.6 mg / L, the blower 2 Hz is reduced until the DO value is between 0.2 and 0.6 mg / L.

[0020] Preferably, the iron ion online detector timely adjusts the pulse DC power supply voltage according to the iron ion concentration. When the iron ion concentration in the iron ion online detector is greater than 50 mg / L, the pulse DC power supply voltage is reduced until the iron ion concentration is within the range of 10-30 mg / L; when the iron ion concentration is less than 10 mg / L, the pulse DC power supply voltage is increased until the iron ion concentration is within the range of 10-30 mg / L.

[0021] An electrochemical reaction device is set up in the micro-oxygen zone. Through the action of the electric field, the electron transfer of the microbial system is strengthened. The iron ions precipitated from the electrode participate in the synthesis and expression of many genes and enzymes, and can act as electron acceptors in the electron transfer chain and ligand of the enzyme to ensure the smooth progress of the microbial metabolism process and achieve the enrichment and directional regulation of the dominant functional bacteria. In addition, the active substances such as OH and [H] produced by electrochemistry will attack the difficult-to-degrade organic matter to open the ring and break the chain, further reducing the COD of the effluent. The insoluble iron hydroxide produced by electrochemistry will complex the phosphate in the system, further reducing the total phosphorus of the effluent, and achieving the effluent COD less than 30mg / L, total nitrogen less than 5mg / L, and total phosphorus less than 0.2mg / L.

[0022] Compared with the prior art, the beneficial effects of the present invention include:

[0023] The present invention proposes a five-stage reaction and two-stage aeration strategy, which is coupled with an electrochemical enhancement mechanism. The electron transfer of the system is accelerated through electrochemical reactions. The electrochemically precipitated iron ions promote the metabolism of microorganisms to achieve the enrichment and directional regulation of dominant functional bacteria. It can significantly reduce the cost of sewage treatment, improve treatment efficiency, and provide an effective solution for the removal of highly complex pollutants. It is of great significance to promote technological progress and sustainable development in the field of sewage treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural schematic diagram of a sewage electrochemical coupled microbial treatment device provided by the present invention.

[0025] Among them: 1- anaerobic zone; 2- first anoxic zone; 3- second anoxic zone; 4- aerobic zone; 41- microporous aeration hose 1; 42- fluidized bed filler; 43- aeration valve 1; 44- aeration flowmeter 1; 45- blower 1; 46- DO online detector 1; 5- microaerobic zone; 51- DO online detector 2; electrochemical reaction device 52-; 53- iron ion online detector; 54- microporous aeration hose 2; 55- electrolytic cell; 56- pulsed DC power supply; 57- aeration valve 2; 58- aeration flowmeter 2; 59- blower 2; 6- sedimentation zone; 7- sludge return pump; 8- internal return pump. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0027] Example 1

[0028] This embodiment provides a sewage electrochemical coupled microbial treatment method, comprising the following steps:

[0029] S1. Pump the sewage into the anaerobic zone 1. Sugar source accumulating microorganisms convert organic matter into internal carbon, ammonia assimilation bacteria convert ammonia nitrogen into internal nitrogen source, and phosphorus-releasing bacteria release a large amount of phosphoric acid while taking organic matter as internal carbon source. Calculate the internal carbon source conversion rate, the contribution rate of ammonia nitrogen removal by assimilation, and the contribution rate of denitrification to adjust the frequency of the sludge return pump 7.

[0030] S2, pumping the effluent from the anaerobic zone 1 into the first anoxic zone 2, the ammonia assimilation bacteria further convert the ammonia nitrogen into an internal nitrogen source, the denitrifying phosphorus-accumulating bacteria absorb the extracellular phosphate, and reduce the nitrate nitrogen to nitrogen gas, so as to achieve simultaneous denitrification and phosphorus removal, calculate the denitrification contribution rate of the denitrification and phosphorus removal process, and adjust the frequency of the internal reflux pump 8;

[0031] S3, pump the effluent from the first anoxic zone 2 into the second anoxic zone 3, and then into the aerobic zone 4 for nitrification and ammonia nitrogen removal reaction, while the phosphate-absorbing bacteria convert phosphate into intracellular substances, calculate the nitrification contribution rate in the aerobic zone 4, and maintain the DO value within the range of 0.8-1.5 mg / L;

[0032] S4, the effluent from aerobic zone 4 enters microaerobic zone 5, where the trace nitrogen and phosphorus are reduced under the action of electrochemical reaction and microorganisms, maintaining the DO value within the range of 0.2-0.6 mg / L and the iron ion concentration within the range of 10-30 mg / L;

[0033] S5, the water from the micro-oxygen zone 5 enters the sedimentation zone 6 for mud and water separation.

[0034] like Figure 1 , a sewage electrochemical coupled microbial treatment device as described above, comprises an anaerobic zone 1, a first anoxic zone 2, a second anoxic zone 3, an aerobic zone 4, a microaerobic zone 5 and a sedimentation zone 6 arranged in sequence, and the treated water can be transferred between the zones through pipes and pumps. The microaerobic zone 5 is provided with a DO online detector 2 51, an electrochemical reaction device 52 and an iron ion online detector 53.

[0035] A sludge return pump 7 is arranged between the anaerobic zone 1 and the sedimentation zone 6 , and an internal return pump 8 is arranged between the first anoxic zone 2 and the micro-aerobic zone 5 .

[0036] The aerobic zone 4 is provided with a microporous aeration hose 141, a fluidized bed filler 42, an aeration valve 143, an aeration flowmeter 144 and a blower 145. The aerobic zone 4 is provided with a DO online detector 146. When the DO value is greater than 1.5 mg / L, the aeration valve 143 opening is reduced by 5% until the DO value is within the range of 0.8-1.5 mg / L, and the opening is ensured to remain unchanged; when the aeration valve 143 opening is 5%, and the DO value still cannot be within the range of 0.8-1.5 mg / L, the blower 145 Hz is reduced until the DO value is within the range of 0.8-1.5 mg / L. The service area of ​​the microporous aeration hose 141 is 0.3m 2 / m, ventilation volume 0.5m 3 / (h·m), oxygen utilization rate is 30-50%.

[0037] The micro-oxygen zone 5 is provided with a microporous aeration hose 254, an electrolytic cell 55, a pulsed DC power supply 56, an aeration valve 257, an aeration flowmeter 258 and a blower 259. When the DO value measured by the DO online detector 251 is greater than 0.6 mg / L, the opening of the aeration valve 257 is reduced by 5% until the DO value is between 0.2 and 0.6 mg / L, and the opening is ensured to remain unchanged; when the opening of the aeration valve 257 is 5%, and the DO value still cannot be between 0.2 and 0.6 mg / L, the blower 259 Hz is reduced until the DO value is between 0.2 and 0.6 mg / L.

[0038] The explanations of the English letters in the following text are as follows: R1 is the sludge return ratio of the sludge return pump 7, and R2 is the internal return ratio of the internal return pump 8; the subscript "inf" refers to the content of the substance when the sewage enters a sewage electrochemically coupled microbial treatment device; "eff" refers to the content of the substance when the sewage is discharged from a sewage electrochemically coupled microbial treatment device; "ana" refers to the content of the substance in the sewage after the sewage is treated in the anaerobic zone 1; "ano1" refers to the content of the substance in the sewage after the sewage is treated in the first anoxic zone 2; "ano2" refers to the content of the substance in the sewage after the sewage is treated in the second anoxic zone 3; "r1" refers to the content of the substance in the sewage after the sewage is treated in the aerobic zone 4; "r2" refers to the content of the substance in the sewage after the sewage is treated in the micro-aerobic zone 5.

[0039] The specific process of sewage treatment in this embodiment is as follows:

[0040] 1. Take sewage sample 1 and first enter anaerobic zone 1, where sugar source accumulating microorganisms (GAO S ) convert organic matter into internal carbon sources and provide carbon source support for denitrification; ammonia assimilation bacteria convert ammonia nitrogen into internal nitrogen sources; phosphorus releasing bacteria (PAO S ) releases a large amount of phosphate while taking up organic matter as internal carbon source (PHA).

[0041] The volume calculation formula of anaerobic zone 1 is as follows:

[0042] V0=t0*Q

[0043] V0 is the volume of anaerobic zone 1, t0 is the hydraulic retention time, which is generally 1-3 hours, Q is the designed treatment flow, m 3 / h.

[0044] The theoretical conversion rate of internal carbon source in anaerobic zone 1 The calculation formula is as follows:

[0045]

[0046] The COD conversion rate σ was measured along the reactor. CODThe calculation formula is as follows:

[0047]

[0048] Calculating the internal carbon source conversion rate can evaluate the metabolic activities of microorganisms in the anaerobic zone 1, especially the activities of sugar-accumulating microorganisms GAOs and phosphate-accumulating bacteria PAOs. These microorganisms decompose the internal carbon source in the anoxic zone and provide carbon source support for the denitrification process.

[0049] The calculation formula for the contribution rate of assimilation to the removal of ammonia nitrogen in anaerobic zone 1 is as follows:

[0050]

[0051] The formula for calculating the nitrate reduction concentration in anaerobic zone 1 is as follows:

[0052]

[0053] The calculation formula for the contribution rate of denitrification in anaerobic zone 1 is as follows:

[0054]

[0055] By calculating the internal carbon source conversion rate, the contribution rate of ammonia nitrogen removal by assimilation, and the contribution rate of denitrification, the frequency of the sludge return pump 7 is adjusted in time to maximize the internal carbon source conversion and nitrogen and phosphorus removal.

[0056] Second, the anaerobic effluent enters the first anoxic zone 2, where ammonia assimilation bacteria further convert ammonia nitrogen into internal nitrogen sources, and denitrifying phosphorus accumulation bacteria (DPAO S ) absorbs extracellular phosphate and reduces nitrate nitrogen to nitrogen gas, achieving simultaneous nitrogen and phosphorus removal, breaking through the difficulties of traditional aerobic nitrogen and phosphorus removal with high aeration energy consumption and large space.

[0057] The formula for calculating the reduced nitrate concentration in the anoxic zone is as follows:

[0058]

[0059] The calculation formula for the contribution rate of assimilation to the removal of ammonia nitrogen in the anoxic zone is as follows:

[0060]

[0061] The calculation formula for the contribution rate of denitrification in the anoxic zone is as follows:

[0062]

[0063] The calculation formula for nitrate removal rate in anoxic zone is as follows:

[0064]

[0065] The calculation formula of COD theoretical consumption value in the denitrification process of anoxic zone is as follows:

[0066]

[0067] The actual COD consumption value calculation formula of the denitrification process in the anoxic zone is as follows:

[0068]

[0069] The theoretical phosphate value calculation formula assuming that no phosphorus removal process occurs in the anoxic zone is as follows:

[0070]

[0071] The calculation formula for the denitrification contribution rate of the denitrification phosphorus removal process in the anoxic zone is as follows:

[0072]

[0073] The call calculates the COD content changes along the process, determines the denitrification contribution rate of the denitrification phosphorus removal process, and timely adjusts the frequency of the internal reflux pump 8 to achieve maximum denitrification phosphorus removal and nitrogen removal.

[0074] The first anoxic zone 2 is equipped with a submersible mixer and a dephosphorization reflux pump. The volume calculation formula of the first anoxic zone 2 is as follows:

[0075] V1=R1*V2 / R2 / 2

[0076] V1 is the volume of the first anoxic zone 2, and V2 is the volume of the second anoxic zone 3.

[0077] 3. The water from the first anoxic zone 2 enters the second anoxic zone 3. The volume calculation formula of the second anoxic zone 3 is as follows:

[0078] V2=N0-N e / q nd

[0079] N0 is the total nitrogen in the influent, N e is the total nitrogen in the effluent, q nd is the denitrification rate, which ranges from 0.1 to 0.3.

[0080] 4. The effluent from the second anoxic zone 3 enters the aerobic zone 4. The aerobic zone 4 is provided with a microporous aeration hose 141, a fluidized bed filler 42, an aeration valve 143, an aeration flow meter 144, and a blower 145. The volume calculation formula of the aerobic zone 4 is as follows:

[0081] V4=Y t θ c (S0-S e ) / 2*(X*f * (1+K d* θc ))

[0082] S0 is the influent BOD5; S e is the effluent BOD5; Y t is the total sludge yield coefficient, which is between 0.6 and 0.8; X is the suspended solid concentration of the mixed liquor, which is between 6000 and 8000 mg / L; f is the ratio coefficient of VSS to SS in the mixed liquor, which is between 0.6 and 0.8; K d θ is the sludge self-oxidation metabolism coefficient, and its value is between 0.03-0.05. c It is the sludge age, and its value is between 13 and 20.

[0083] The calculation formula of the internal reflux pump 8 ratio is as follows:

[0084] R2=(N0-N e ) / N0 / (1-(N0-N e ) / N0)

[0085] N0 is the total nitrogen in the influent, N e is the effluent total nitrogen,

[0086] A DO online detector 1 46 is set in the aerobic zone 4. When the DO value is greater than 1.5 mg / L, the opening of the aeration valve 1 43 is reduced by 5% until the DO value is between 0.8 and 1.5 mg / L, and the opening is ensured to remain unchanged. When the opening of the aeration valve 1 43 is 5%, and the DO value still cannot be between 0.8 and 1.5 mg / L, the blower 1 45 Hz is reduced until the DO value is between 0.8 and 1.5 mg / L.

[0087] Microporous aeration hose 1 41 Service area 0.3m 2 / m, ventilation volume 0.5m 3 / (h·m), oxygen utilization rate can reach 30-50%, and the aeration hose can be regularly held and deflated to solve the problem of scaling and clogging of traditional aeration.

[0088] The fluidized bed filler 42 is a three-layer hollow circle, each circle has one edge inside and 36 edges outside, the specific surface area can reach 600, and the double specific area is as high as 860 or more.

[0089] Contribution rate of nitrification in aerobic zone 4 to remove ammonia nitrogen

[0090]

[0091] 5. The effluent from the aerobic zone 4 enters the micro-aerobic zone 5. The micro-aerobic zone 5 is provided with a microporous aeration hose 2 54, an electrolytic cell 55, a pulsed DC power supply 56, an aeration valve 2 57, an aeration flow meter 2 58, and a blower 2 59. The volume calculation formula of the micro-aerobic zone 5 is as follows:

[0092] V3=Y t θ c (S0-S e ) / 2*(X*f*(1+K d *θ c ))

[0093] Where: S0 is the influent BOD5; S e is the effluent BOD5; Y t is the total sludge yield coefficient, ranging from 0.6 to 0.8; X is the suspended solids concentration of the mixed liquor, ranging from 8000 to 12000 mg / L; f is the ratio coefficient of VSS to SS in the mixed liquor, ranging from 0.6 to 0.8; K d θ is the sludge self-oxidation metabolism coefficient, and its value is between 0.03-0.05. c It is the sludge age, and its value is between 13 and 20.

[0094] A DO online detector 2 51 is set in the micro-aerobic zone 5. When the DO value is greater than 0.6 mg / L, the opening of the aeration valve 2 57 is reduced by 5% until the DO value is between 0.2 and 0.6 mg / L, and the opening is ensured to remain unchanged. When the opening of the aeration valve 2 57 is 5%, and the DO value still cannot be between 0.2 and 0.6 mg / L, the blower 2 59 Hz is reduced until the DO value is between 0.2 and 0.6 mg / L.

[0095] The micro-oxygen zone 5 is provided with an electrochemical reaction device 52, which strengthens the electron transfer of the microbial system through the action of the electric field. The iron ions precipitated from the electrode participate in the synthesis and expression of many genes and enzymes, and can act as electron acceptors in the electron transfer chain and ligand of the enzyme, ensuring the smooth progress of the microbial metabolic process, and realizing the enrichment and directional regulation of the dominant functional bacteria. In addition, the active substances such as OH and [H] generated by electrochemistry will attack the difficult-to-degrade organic matter to open the ring and break the chain, further reducing the COD of the effluent. The insoluble iron hydroxide generated by electrochemistry will complex the phosphate in the system, further reducing the total phosphorus of the effluent, and achieving the effluent COD less than 30mg / L, the total nitrogen less than 5mg / L, and the total phosphorus less than 0.2mg / L.

[0096] The micro-oxygen zone 5 is provided with an online iron ion detector 53, and the voltage of the pulse DC power supply 56 is adjusted in time according to the iron ion concentration. The system sets the iron ion concentration to 10-30 mg / L. When the iron ion concentration is greater than 50 mg / L, the voltage of the pulse DC power supply 56 is reduced until the iron ion concentration is 10-30 mg / L; when the iron ion concentration is less than 10 mg / L, the voltage of the pulse DC power supply 56 is increased until the iron ion concentration is 10-30 mg / L; the calculation formula of iron ions and the voltage of the pulse DC power supply 56 is as follows:

[0097] C=28It / F / V

[0098] Where: C is the mass concentration of iron ions, mg / L; I is the current density, A / cm 2 ; t is the hydraulic retention time of micro-oxygen zone 5, s; F is the Faraday constant, 96 487C / mol; V is the volume of micro-oxygen zone 5, L.

[0099] 6. The effluent from the micro-aerobic zone 5 enters the sedimentation zone 6. The sedimentation tank adopts a rectangular circumferential inlet and outlet sedimentation tank and is equipped with a sludge return pump 7. This unit is mainly used to achieve rapid separation of mud and water. The calculation formula for the sedimentation zone 6 is as follows:

[0100] S=Q*(1+R1) / q

[0101] S is the area of ​​the sedimentation zone 6, q is the surface load, which is generally 0.8-2m 3 / (m 2 *h), Q is the designed processing flow, m 3 / h.

[0102] The length L of the sedimentation tank is the same as that of the biological tank.

[0103] Sedimentation tank width B = S / L,

[0104] The calculation formula of sludge return pump 7 ratio is as follows:

[0105] R1=X / (X1-X)

[0106] X is the concentration of suspended solids in the mixed liquor, which is between 6000-8000 mg / L; X1 is the concentration of return sludge, which is between 8000-12000 mg / L;

[0107] The calculation formula for the contribution rate of ammonia nitrogen removal by assimilation in the secondary sedimentation tank is as follows:

[0108]

[0109] 7. The water produced from the sedimentation tank overflows into the tubular ultraviolet disinfector, and the bacteria and viruses in the water are killed before being discharged in compliance with the standards.

[0110] The contents of various substances in sewage sample 1 before and after treatment are shown in Table 1.

[0111] Table 1 Concentration of various substances before and after treatment of sewage sample 1

[0112]

[0113] As can be seen from Table 1, the concentrations of various substances in sewage sample 1 before treatment were COD 200-300 mg / L, ammonia nitrogen 40-50 mg / L, TN 40-60 mg / L, and TP 1-5 mg / L; after treatment, COD < 30 mg / L, ammonia nitrogen < 2 mg / L, TN < 8 mg / L, and TP < 0.2 mg / L. During the treatment process, the removal rate of ammonia nitrogen assimilation reached 68.1%, the removal rate of denitrification phosphorus removal reached 52.9%, the removal rate of denitrification phosphorus removal reached 68.5%, and the removal rate of electrochemical phosphorus removal reached 11.5%.

[0114] Example 2

[0115] The sewage electrochemical coupled microbial treatment method and device in this embodiment are the same as those in Example 1. The sewage treated in this embodiment is sewage sample 2.

[0116] The contents of various substances in sewage sample 2 before and after treatment are shown in Table 2.

[0117] Table 2 Concentration of various substances before and after treatment of sewage sample 2

[0118]

[0119] As can be seen from Table 2, the concentrations of various substances in sewage sample 2 before treatment were COD150-200 mg / L, ammonia nitrogen40-50 mg / L, TN40-50 mg / L, and TP1-6 mg / L; the COD in the effluent after treatment was <30 mg / L, ammonia nitrogen<1 mg / L, TN<8 mg / L, and TP<0.2 mg / L, among which the removal rate of ammonia nitrogen assimilation reached 64.1%, the removal rate of denitrification phosphorus removal reached 55.9%, the removal rate of denitrification phosphorus removal reached 66.5%, and the removal rate of electrochemical phosphorus removal reached 13.5%.

[0120] Comparative Example 1

[0121] The wastewater sample 1 was treated by the traditional nitrification and denitrification treatment method, and its nitrogen removal efficiency was only 13.5%, and the aerobic phosphorus removal efficiency was only 19.1%.

[0122] Comparative Example 2

[0123] The wastewater sample 2 was treated by the traditional nitrification and denitrification treatment method, and its nitrogen removal efficiency was only 11.5%, and the aerobic phosphorus removal efficiency was only 17.1%.

[0124] The specific implementation of the present invention described above does not constitute a limitation on the protection scope of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A sewage electrochemical coupled microbial treatment method, characterized in that: The steps include: S1. Pump the sewage into the anaerobic zone. Sugar source accumulating microorganisms convert organic matter into internal carbon, ammonia assimilation bacteria convert ammonia nitrogen into internal nitrogen source, and phosphorus-releasing bacteria release a large amount of phosphoric acid while taking organic matter as internal carbon source. Calculate the internal carbon source conversion rate, the contribution rate of ammonia nitrogen removal by assimilation, and the contribution rate of denitrification to adjust the frequency of the sludge return pump; S2, pumping the effluent from the anaerobic zone into the first anoxic zone, wherein the ammonia assimilation bacteria further convert the ammonia nitrogen into an internal nitrogen source, and the denitrifying phosphorus-accumulating bacteria absorb the extracellular phosphate and reduce the nitrate nitrogen to nitrogen gas, thereby achieving simultaneous denitrification and phosphorus removal, calculating the denitrification contribution rate of the denitrification and phosphorus removal process, and adjusting the frequency of the internal reflux pump; S3, pump the effluent from the first anoxic zone into the second anoxic zone, and then into the aerobic zone for nitrification and ammonia nitrogen removal reaction. At the same time, the phosphate of phosphorus-absorbing bacteria is converted into intracellular substances, and the contribution rate of nitrification in the aerobic zone is calculated to maintain the DO value within the range of 0.8-1.5mg / L; S4, the effluent from the aerobic zone enters the micro-aerobic zone, where the trace nitrogen and phosphorus are reduced under the action of electrochemical reaction and microorganisms, maintaining the DO value within the range of 0.2-0.6 mg / L and the iron ion concentration within the range of 10-30 mg / L; S5. The water from the micro-oxygen zone enters the sedimentation zone for mud and water separation.

2. A sewage electrochemical coupled microbial treatment device as claimed in claim 1, characterized in that: It comprises an anaerobic zone, a first anoxic zone, a second anoxic zone, an aerobic zone, a microaerobic zone and a precipitation zone which are arranged in sequence. The microaerobic zone is provided with a DO online detector 2, an electrochemical reaction device and an iron ion online detector.

3. The device according to claim 2, characterized in that A sludge return pump is arranged between the anaerobic zone and the sedimentation zone, and an internal return pump is arranged between the first anoxic zone and the micro-aerobic zone.

4. The device according to claim 2, characterized in that The aerobic zone is provided with a microporous aeration hose 1, a fluidized bed filler, an aeration valve 1, an aeration flow meter 1 and a blower 1.

5. The device according to claim 4, characterized in that A DO online detector 1 is provided in the aerobic zone. When the DO value is greater than 1.5 mg / L, the opening of the aeration valve 1 is reduced by 5% until the DO value is within the range of 0.8-1.5 mg / L, and the opening is ensured to remain unchanged. When the opening of the aeration valve 1 is 5%, and the DO value still cannot be within the range of 0.8-1.5 mg / L, the blower is reduced by 1 Hz until the DO value is within the range of 0.8-1.5 mg / L.

6. The device according to claim 4, characterized in that The service area of ​​the microporous aeration hose 1 is 0.3m 2 / m, ventilation volume 0.5m 3 / (hm), oxygen utilization rate is 30-50%.

7. The device according to claim 2, characterized in that The micro-oxygen zone is provided with a microporous aeration hose 2, an electrolytic cell, a pulsed DC power supply, an aeration valve 2, an aeration flow meter 2 and a blower 2.

8. The device according to claim 7, characterized in that When the DO value measured by the DO online detector 2 is greater than 0.6 mg / L, the opening of the aeration valve 2 is reduced by 5% until the DO value is between 0.2 and 0.6 mg / L, and the opening is ensured to remain unchanged; when the opening of the aeration valve 2 is 5%, and the DO value still cannot be between 0.2 and 0.6 mg / L, the blower 2 Hz is reduced until the DO value is between 0.2 and 0.6 mg / L.

9. The device according to claim 2, characterized in that The iron ion online detector timely adjusts the pulse DC power supply voltage according to the iron ion concentration. When the iron ion concentration in the iron ion online detector is greater than 50 mg / L, the pulse DC power supply voltage is reduced until the iron ion concentration is within the range of 10-30 mg / L; when the iron ion concentration is less than 10 mg / L, the pulse DC power supply voltage is increased until the iron ion concentration is within the range of 10-30 mg / L.

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