A microbial-driven fenton oxidation device based on iron cycle

Abstract

A kind of microbial driving-based iron cycle fenton oxidation device, including acid adjusting pool, catalyst mixing pool, oxidation reaction pool for fenton oxidation reaction in sequence, the product of fenton oxidation reaction is separated Fe (OH) 3 sludge in sequence through neutralization reaction pool and precipitation pool, reduced to divalent iron through dissimilatory iron reduction reaction in dissimilatory iron reduction membrane bioreactor and backflow to catalyst mixing pool, by embedding dissimilatory iron reduction membrane bioreactor, realize internal iron cycle of fenton oxidation process, on the one hand, can greatly reduce catalyst dosage, on the other hand, reduce the sludge amount mainly with Fe (OH) 3, under the condition of guaranteeing same effluent water quality, solve the two major problems of large iron reagent dosage and sludge amount existing in traditional fenton oxidation system.

Description

Technical Field

[0001] This utility model belongs to the field of industrial wastewater treatment technology, specifically relating to a microbial-driven iron circulation Fenton oxidation device. Background Technology

[0002] The Fenton reaction is an inorganic chemical reaction, the essence of which is the reaction of Fe(II) ions (Fe... 2+ The chain reaction between hydroxyl radicals and hydrogen peroxide catalyzes the generation of hydroxyl radicals (·OH), which have strong oxidizing power. The hydroxyl radicals (·OH) react with organic matter RH to generate free radicals (R·), which are further oxidized to generate CO2 and H2O, thereby greatly reducing the COD of wastewater.

[0003] The Fenton reaction can oxidize most organic pollutants in water with non-selectivity or low selectivity, and is particularly suitable for the oxidation treatment of organic pollutants that are difficult to degrade biologically, have low biodegradability, or are difficult to treat with general chemical oxidants. It has a wide range of applications in the treatment of wastewater such as dyeing and printing wastewater, oily wastewater, phenolic wastewater, coking wastewater, nitrobenzene-containing wastewater, and diphenylamine wastewater.

[0004] The Fenton reaction has advantages such as the ability to oxidize and destroy a variety of toxic and harmful organic substances, wide applicability, mild reaction conditions, and simple equipment and operation. However, the traditional Fenton reaction method has disadvantages such as the use of large amounts of reagents, large sludge production, and the fact that much of the sludge is hazardous solid waste. Utility Model Content

[0005] This invention addresses the shortcomings of traditional Fenton technology by providing a microbial-driven iron-circulating Fenton oxidation device and a microbial-driven iron-circulating Fenton oxidation method. This method achieves internal iron circulation, reduces the processing cost of Fenton technology, and is a green and low-carbon process.

[0006] The above-mentioned objective of this utility model is achieved through the following technical solution:

[0007] A microbial-driven iron-cycle Fenton oxidation device includes an oxidation reaction tank for Fenton oxidation, an acidification tank, an external sewage pipe and a sulfuric acid delivery pipe connected to a first inlet and a second inlet of the acidification tank, respectively, and an outlet of the acidification tank connected to a first inlet of a catalyst mixing tank. The second inlet of the catalyst mixing tank is connected to a catalyst delivery pipe, and the outlet of the catalyst mixing tank is connected to the first inlet of the oxidation reaction tank. The second inlet of the oxidation reaction tank is connected to an external oxidant delivery pipe, and the outlet of the oxidation reaction tank is connected to the first inlet of a neutralization reaction tank. The second inlet of the neutralization reaction tank is connected to an external alkali delivery pipe, and the outlet of the neutralization reaction tank is connected to the inlet of a sedimentation tank. The clear liquid outlet at the top of the sedimentation tank is connected to an external clear liquid delivery pipe, and a sludge discharge pipe at the bottom of the sedimentation tank is connected to the feed pipe of a buffer tank. The outlet of the buffer tank is connected to an anaerobic sequencing batch reactor (SBR) containing dissimilar iron-reducing bacteria. The outlet of the anaerobic SBR is connected to the inlet of a membrane module, the permeate outlet of the membrane module is connected to a third inlet of the catalyst mixing tank, and the sludge outlet of the membrane module is connected to the buffer tank.

[0008] The catalyst transported by the catalyst transport pipeline as described above is an Fe(II) salt.

[0009] As mentioned above, the oxidant transported by the oxidant transport pipeline is hydrogen peroxide.

[0010] As described above, a heating device and a pH meter are installed in the buffer tank. The buffer tank is also equipped with a pH adjustment port, which is connected to a corresponding external alkali delivery pipeline.

[0011] As mentioned above, the alkali transported by the alkali transport pipeline is sodium hydroxide.

[0012] As mentioned above, the membrane module is an inorganic membrane module.

[0013] As mentioned above, the inorganic membrane module is a silicon carbide membrane module, and the pore size of the silicon carbide membrane does not exceed 40 nm.

[0014] As mentioned above, agitators are installed in the acid adjustment tank, catalyst mixing tank, oxidation reaction tank, and neutralization reaction tank.

[0015] The beneficial technical effects of this utility model are:

[0016] For every 1 kg of ferrous sulfate added, 0.35 kg of Fe(OH)3 is theoretically produced. The Fe(OH)3 sludge produced by the Fenton reaction of this invention is circulated inside the heterogeneous iron reduction membrane bioreactor, reducing the discharge and disposal of this part of the sludge.

[0017] The heterogeneous iron reduction membrane bioreactor combines two process methods: heterogeneous iron reduction bacterial reaction and membrane separation. Through the heterogeneous iron reduction membrane bioreactor, ferric iron can be reduced to Fe(II) and recycled within the Fenton system, which can save about 40-65% of the amount of ferrous sulfate catalyst added.

[0018] In the heterogeneous iron reduction membrane bioreactor, the main bioreactor adopts an anaerobic sequencing batch reactor. Because it has its own static sedimentation process, it reduces the load on subsequent membrane modules and extends the service life of the membrane.

[0019] The installation of membrane modules can, on the one hand, increase the sludge concentration in the anaerobic bioreactor and reduce sludge loss, thereby improving the reduction efficiency of dissimilar iron; on the other hand, it can improve the quality of the circulating iron solution in the system through the interception effect of the membrane.

[0020] Overall, this invention reduces the costs of Fenton reaction reagents and solid waste disposal. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of a microbial-driven iron-cycle Fenton oxidation device.

[0022] In the diagram: 1-Acidity adjustment tank; 2-Catalyst mixing tank; 3-Oxidation reaction tank; 4-Neutralization reaction tank; 5-Sedimentation tank; 6-Dissimilar iron reduction membrane bioreactor; 7-Buffer tank; 8-Anaerobic sequencing batch reactor; 9-Membrane module. Detailed Implementation

[0023] To facilitate understanding and implementation of this utility model by those skilled in the art, the present utility model will be further described in detail below with reference to embodiments. The embodiments described herein are only for illustration and explanation and are not intended to limit the present utility model.

[0024] like Figure 1 As shown, a microbial-driven iron recycling Fenton oxidation device includes, in sequence, an acid adjustment tank 1, a catalyst mixing tank 2, an oxidation reaction tank 3 for the Fenton oxidation reaction, a neutralization reaction tank 4, a precipitation tank 5, and a dissimilar iron reduction membrane bioreactor 6.

[0025] External sewage pipes and sulfuric acid delivery pipes are connected to the first and second inlets of acidification tank 1, respectively. The outlet of acidification tank 1 is connected to the first inlet of catalyst mixing tank 2. The second inlet of catalyst mixing tank 2 is connected to catalyst delivery pipes. The outlet of catalyst mixing tank 2 is connected to the first inlet of oxidation reaction tank 3. The second inlet of oxidation reaction tank 3 is connected to external oxidant delivery pipes. The outlet of oxidation reaction tank 3 is connected to the first inlet of neutralization reaction tank 4. The second inlet of neutralization reaction tank 4 is connected to external alkali delivery pipes. The outlet of neutralization reaction tank 4 is connected to the inlet of sedimentation tank 5. The clear liquid outlet at the top of sedimentation tank 5 is connected to external clear liquid delivery pipes. The sludge discharge pipe at the bottom of sedimentation tank 5 is connected to the inlet of dissimilar iron reduction membrane bioreactor 6 containing dissimilar iron reduction bacteria. The product water outlet of dissimilar iron reduction membrane bioreactor 6 is connected to the third inlet of catalyst mixing tank 2.

[0026] A mixer is installed in the acid conditioning tank 1. Sulfuric acid is added to the acid conditioning tank 1 and mixed with the sewage through mechanical stirring to control the pH of the sewage to 3-4, thereby ensuring the acidic conditions required for the subsequent Fenton reaction.

[0027] The catalyst added to the catalyst mixing tank 2 is Fe(II) salt. The Fe(II) salt comes from two sources: one is the Fe(II) salt contained in the product water of the heterogeneous iron reduction membrane bioreactor 6, and the other is the supplement by adding ferrous sulfate to the second inlet of the catalyst mixing tank 2. The catalyst Fe(II) salt and the sewage flowing into the catalyst mixing tank 2 are mixed by a stirrer installed in the catalyst mixing tank 2.

[0028] An agitator is installed in oxidation reaction tank 3. The added oxidant is hydrogen peroxide (H2O2). Through mechanical stirring, the catalyst, oxidant and sewage are fully mixed, and a Fenton reaction occurs, generating hydroxyl radicals (·OH), which convert the recalcitrant organic matter into easily degradable or harmless substances.

[0029] The alkali added to the second inlet of neutralization reaction tank 4 is sodium hydroxide. The mixture is mechanically mixed using a stirrer to adjust the wastewater after the Fenton reaction to neutral. During this process, Fe(OH)3 sludge will be formed.

[0030] The sedimentation tank 5 performs solid-liquid separation on the neutralized mixed liquid output from the neutralization reaction tank 4. The supernatant is discharged externally, and the precipitated Fe(OH)3 sludge is sent to the heterogeneous iron reduction membrane bioreactor 6 through the sludge discharge pipe as raw material for the heterogeneous iron reduction membrane bioreactor 6.

[0031] The heterogeneous iron reduction membrane bioreactor 6 includes a buffer tank 7, an anaerobic sequencing batch reactor 8, and a membrane module 9 connected in sequence. The feed pipe of the buffer tank 7 serves as the input port of the heterogeneous iron reduction membrane bioreactor 6 and is connected to the sludge discharge pipe of the sedimentation tank 5. The output port of the buffer tank 5 is connected to the anaerobic sequencing batch reactor 8 containing heterogeneous iron reducing bacteria. The effluent port of the anaerobic sequencing batch reactor 8 is connected to the influent port of the membrane module 9. The permeate port of the membrane module 9 serves as the permeate port of the heterogeneous iron reduction membrane bioreactor 6 and is connected to the third input port of the catalyst mixing tank 2. The sludge discharge port of the membrane module 9 is connected to the buffer tank 7.

[0032] This invention embeds a dissimilar iron reduction membrane bioreactor 6 into a traditional Fenton reaction system. The Fe(OH)3 sludge produced in the neutralization reaction tank 4 circulates inside the dissimilar iron reduction membrane bioreactor 6. Excess sludge is discharged periodically. Through the respiration of internal microorganisms, the process of reducing ferric iron to Fe(II) is completed and dissolved in the supernatant of the anaerobic sequencing batch reactor 8. The high-efficiency filtration of the membrane module 9 reduces the loss of dissimilar iron reducing bacteria and improves the quality of the effluent, which acts as a catalyst.

[0033] Furthermore, the buffer tank 7 is also equipped with a stirrer (for adjusting water quality and preventing sludge deposition), a heating device, and a pH meter. The heating device in the buffer tank 7 is used to adjust the temperature in real time. The buffer tank 7 is also equipped with a pH adjustment port, which is connected to a corresponding external alkali delivery pipeline. The pH meter is used to monitor the acid-base environment in the buffer tank 7 in real time, and alkali (such as sodium hydroxide) is added through the pH adjustment port to adjust the acid-base environment in the buffer tank 7. Through heating, pH adjustment, and stirring homogenization, a suitable biological reaction environment for dissimilatory iron-reducing bacteria is created, thereby improving the reaction efficiency in the anaerobic sequencing batch reactor 8. In addition, the buffer tank 7 is used to provide buffer volume to regulate water flow, and a water pump is also provided to distribute the flow rate according to the operating sequence of the anaerobic sequencing batch reactor 8.

[0034] The heterogeneous iron reduction membrane bioreactor 6 uses an anaerobic sequencing batch reactor 8, which employs a single reactor to complete the sequential operation of water intake, reaction, sedimentation and drainage.

[0035] The anaerobic sequencing batch reactor 8 adopts an intermittent operation mode. The four reaction processes of water inlet, reaction, sedimentation and drainage constitute one operating cycle, which is carried out in a loop. The cycle length can be adjusted according to the actual situation.

[0036] The anaerobic sequencing batch reactor 8 is equipped with a stirrer; when the water influent begins, the stirrer starts working to ensure that the dissimilatory iron reducing bacteria and Fe(OH)3 sludge are fully mixed, and the stirrer stops working after the reaction process is completed.

[0037] The anaerobic sequencing batch reactor 8 has a closed structure, ensuring that the dissimilar iron-reducing bacteria are in an anaerobic state, thus facilitating their growth.

[0038] The supernatant after sedimentation in the anaerobic sequencing batch reactor 8 is discharged to the membrane module 9 through a decanter. The anaerobic sequencing batch reactor 8 does not require a water distribution system, external solids recirculation, or any short-circuiting phenomenon, making it simple and reliable to operate; moreover, it does not require a separate sedimentation tank, and solid-liquid separation can be initially carried out within the anaerobic sequencing batch reactor 8, reducing fouling of the subsequent membrane module 9;

[0039] The membrane module 9 is equipped with conventional equipment such as a water pump and a cleaning device. The membrane module 9 is an inorganic membrane module. In this embodiment, the inorganic membrane module is a silicon carbide membrane module. The pore size of the silicon carbide membrane does not exceed 40 nm. The effluent from the decanter connected to the anaerobic sequencing batch reactor 8 is connected to the inlet pipe of the membrane module 9 through a water pump. The permeate from the membrane module 9 is connected to the third inlet of the catalyst mixing tank 2 through a pipeline to provide the required oxidant Fe(II) salt for the subsequent Fenton reaction, thereby realizing internal iron circulation.

[0040] The membrane module 9 requires periodic backwashing and chemical cleaning, and is equipped with a cleaning device. The wastewater discharged after cleaning is piped to the buffer tank 7.

[0041] The iron reduction rate of the heterogeneous iron reduction membrane bioreactor 6 is approximately 40-65%.

[0042] Example 2

[0043] A microbial-driven iron cycling Fenton oxidation method, utilizing the microbial-driven iron cycling Fenton oxidation device described in Example 1, comprises the following steps:

[0044] Step 1: External sewage and sulfuric acid enter the acid adjustment tank 1 of the microbial-driven iron circulation Fenton oxidation device. Under mechanical stirring, the sulfuric acid and sewage are fully mixed, and the pH value is adjusted to 3-4. The resulting acidic sewage flows into the catalyst mixing tank 2.

[0045] Step 2: In the initial stage of external wastewater inflow, a preset dose of catalyst is added to the second inlet of the catalyst mixing tank 2, and then the catalyst addition is paused. This allows the initially inflowing wastewater to mix with the externally added catalyst for subsequent Fenton reactions. The subsequent catalyst mainly comes from the Fe(II) salt-rich permeate of the heterogeneous iron reduction membrane bioreactor 6. When the concentration of ferrous iron in the permeate of the membrane module 9 is lower than the concentration threshold, it is considered that the catalyst dosage is insufficient, and the catalyst is added to the second inlet of the catalyst mixing tank 2 until the concentration of ferrous iron in the permeate of the membrane module 9 reaches the concentration threshold, at which point the catalyst addition is paused. During this process, the acidic wastewater and the catalyst, i.e., the Fe(II) salt, are fully mixed through the action of the agitator to obtain wastewater containing the catalyst.

[0046] Step 3: Hydrogen peroxide (H2O2) is added to oxidation reaction tank 3, and simultaneously, wastewater containing the catalyst enters oxidation reaction tank 3 for Fenton oxidation, producing a mixed liquor after Fenton oxidation treatment containing Fe(OH)3 sludge; wherein, the catalyst Fe(II) salt and hydrogen peroxide (H2O2) form Fenton reagent, and hydrogen peroxide (H2O2) reacts with Fe... 2+ Under the catalysis of , highly reactive hydroxyl radicals ·OH are generated. Hydroxyl radicals ·OH have extremely strong oxidizing power. They can effectively oxidize and degrade recalcitrant organic pollutants in wastewater. At the same time, Fe(II) salts are oxidized to generate trivalent iron.

[0047] In oxidation reaction tank 3, the oxidant Fe(II) salt reacts with the oxidant (hydrogen peroxide H2O2) as follows:

[0048] Fe 2+ +H₂O₂→Fe 3+ +(OH) — +OH,

[0049] Step 4: The mixed liquid after Fenton oxidation treatment enters the neutralization reaction tank 4. Under the action of the agitator, the alkali flowing into the second inlet of the neutralization reaction tank 4 is fully mixed with the mixed liquid after Fenton oxidation treatment, and a neutralization reaction occurs, so that the pH value of the wastewater is adjusted to 6-7, and a neutralized mixed liquid is obtained.

[0050] Step 5: Sedimentation tank 5 performs solid-liquid separation on the neutralized mixed liquid output from neutralization reaction tank 4. The Fe(OH)3 sludge in the neutralized mixed liquid is transported to the heterogeneous iron reduction membrane bioreactor 6 through the sludge discharge pipe. The supernatant obtained from solid-liquid separation is discharged through the supernatant outlet connected to the external supernatant delivery pipe.

[0051] In this embodiment, the sedimentation tank 5 is equipped with a water distribution channel, an inclined tube sedimentation zone, an effluent weir, and an effluent trough. The neutral treatment mixture enters the inclined tube sedimentation zone through the water distribution channel. Under static conditions, the Fe(OH)3 sludge in the neutral treatment mixture is separated from the water. The supernatant is discharged sequentially through the effluent weir, effluent trough, and clear liquid outlet at the top of the inclined tube sedimentation zone. The Fe(OH)3 sludge is then transported to the buffer tank 7 of the heterogeneous iron reduction membrane bioreactor 6 by a water pump or gravity through the sludge discharge pipe.

[0052] Step 6: Fe(OH)3 sludge enters buffer tank 7 through sludge discharge pipe. Fe(OH)3 sludge is heated and homogenized by mechanical stirring in buffer tank 7 before entering anaerobic sequencing batch reactor 8.

[0053] Step 7: Under the action of dissimilatory iron-reducing bacteria in the anaerobic sequencing batch reactor 8, ferric iron in Fe(OH)3 sludge is reduced to Fe(II) salt, and the supernatant containing Fe(II) flows out through the decanter to the membrane module 9.

[0054] The dissimilar iron reduction membrane bioreactor 6 maintains a certain concentration of dissimilar iron-reducing bacteria. These bacteria completely oxidize organic matter intracellularly, generating electrons which are then transferred via the intracellular respiratory chain to the extracellular insoluble iron oxide electron acceptor, reducing it to Fe(II) and generating energy to sustain microbial growth. If acetate is used as the organic matter involved in the oxidation, the reaction is as follows:

[0055] CH3COO- + 8Fe(OH)3 + 15H + →8Fe 2+ +2HCO3-+20H2O,

[0056] In the traditional Fenton process: the ratio of iron salt dosage to chemical oxygen demand (COD) dosage is: c(Fe 2+ The ratio of Fe(II) salt to COD (mg / L) is 1:10 to 2:1. When the COD concentration is high, the dosage of Fe(II) salt is larger. Simultaneously, for every 1 kg of ferrous sulfate added, 0.35 kg of Fe(OH)3 is theoretically produced. When the dosage of ferric salt is large, a large amount of sludge mainly composed of Fe(OH)3 is generated. The costs of reagents and sludge disposal are high. Taking the Fenton deep treatment of coking wastewater as an example, the cost of ferric salt and sludge disposal is approximately 3 to 10 yuan.

[0057] Based on the electron transfer characteristics of the dissimilar iron reduction process and the removal efficiency of the product Fe(II) for various pollutants, this invention introduces it into the Fenton process. By using the effluent from the dissimilar iron reduction membrane bioreactor 6 as a catalyst to enter the catalyst mixing tank 2, internal iron circulation is achieved, reducing the amount of external catalyst Fe(II) salt added. This is expected to replace the traditional method of supplying Fe(II) while reducing the amount of Fe(OH)3 sludge and better controlling costs. The amount of Fe(II) salt added can be reduced by 40-65%, and the amount of sludge reduced by about 35-60%.

[0058] Step 8: The permeate from membrane module 9 enters catalyst mixing tank 2 as a catalyst to achieve internal iron circulation. In this embodiment, the wastewater from membrane module 9 is returned to buffer tank 7.

[0059] This invention enables microbial-driven iron cycling. The catalyst has two sources: one is the Fe(II) salt solution produced by the dissimilar iron reduction membrane bioreactor 6, and the other is purchased ferrous sulfate, thereby reducing the dosage of purchased drugs.

[0060] The sedimentation tank 5 is used for solid-liquid separation. The settled sludge is mainly Fe(OH)3 sludge, which is discharged after dewatering. This invention sends the efficiently settled Fe(OH)3 sludge to the heterogeneous iron reduction membrane bioreactor 6 for treatment, where a portion of the Fe(OH)3 sludge undergoes valence conversion, reducing sludge production and thus achieving sludge reduction.

[0061] Preventing the loss of organisms is crucial for anaerobic processes, and inappropriate external capture and recirculation facilities for escaping organisms will negatively impact biological treatment efficiency. This invention utilizes a membrane as an external capture and recirculation facility for escaping organisms, forming an anaerobic membrane bioreactor. Its interception efficiency is far greater than that of traditional sedimentation tanks and other facilities, effectively increasing the sludge concentration in the anaerobic process section, thereby improving its reaction efficiency. Simultaneously, it enhances effluent quality, ensuring that the Fe(II) salt-containing permeate contains fewer impurities, thus maximizing its efficiency as a catalyst.

[0062] For the dissimilar iron reduction membrane bioreactor 6, the commonly used anaerobic process often suffers from problems such as water distribution blockage, poor sedimentation effect, and poor shock resistance. This utility model takes into account the problems that the feed to the bioreactor is Fe(OH)3 sludge and that the cultivation and domestication of dissimilar iron reducing bacteria is relatively difficult. Therefore, an anaerobic sequencing batch reactor 8 is selected as the main bioreactor, which can solve the problems of water distribution blockage and shock load resistance. The anaerobic sequencing batch reactor 8 has the advantages of shock resistance, strong adaptability, flexible operation, good solid-liquid separation effect, and good sludge performance.

[0063] Currently, membrane modules used in membrane bioreactors generally employ organic membranes. Organic membranes are typically cleaned with citric acid or low-concentration hydrochloric acid, and they have poor acid and alkali resistance, while also introducing other ions into the system. This invention uses an inorganic membrane (silicon carbide membrane), which has strong acid and alkali resistance, can be cleaned with sulfuric acid, has strong acid resistance, and does not introduce other ions, thus effectively controlling the quality of its effluent as a catalyst.

[0064] The specific embodiments described herein are merely illustrative examples illustrating the spirit of this utility model. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of this utility model or exceeding the scope defined by the appended claims.

Claims

1. A microbially driven iron circulation Fenton oxidation device, comprising an oxidation reaction tank (3) for the Fenton oxidation reaction, characterized in that, It also includes an acid conditioning tank (1), an external sewage pipe and a sulfuric acid conveying pipe connected to the first inlet and the second inlet of the acid conditioning tank (1) respectively, and the outlet of the acid conditioning tank (1) connected to the first inlet of the catalyst mixing tank (2); the second inlet of the catalyst mixing tank (2) is connected to the catalyst conveying pipe, the outlet of the catalyst mixing tank (2) is connected to the first inlet of the oxidation reaction tank (3), the second inlet of the oxidation reaction tank (3) is connected to the external oxidant conveying pipe, the outlet of the oxidation reaction tank (3) is connected to the first inlet of the neutralization reaction tank (4), and the second inlet of the neutralization reaction tank (4) is connected to the external oxidant conveying pipe. The inlet is connected to an external alkali delivery pipeline, the outlet of the neutralization reaction tank (4) is connected to the inlet of the sedimentation tank (5), the clear liquid outlet at the top of the sedimentation tank (5) is connected to an external clear liquid delivery pipeline, and the sludge discharge pipeline at the bottom of the sedimentation tank (5) is connected to the feed pipe of the buffer tank (7). The outlet of the buffer tank (7) is connected to an anaerobic sequencing batch reactor (8) containing dissimilar iron reducing bacteria. The outlet of the anaerobic sequencing batch reactor (8) is connected to the inlet of the membrane module (9). The product water outlet of the membrane module (9) is connected to the third inlet of the catalyst mixing tank (2), and the sludge outlet of the membrane module (9) is connected to the buffer tank (7).

2. The microbial-driven iron circulation Fenton oxidation device according to claim 1, characterized in that, The catalyst transported by the catalyst transport pipeline is Fe(II) salt.

3. The microbial-driven iron circulation Fenton oxidation device according to claim 1, characterized in that, The oxidant transported by the oxidant transport pipeline is hydrogen peroxide.

4. The microbial-driven iron circulation Fenton oxidation device according to claim 3, characterized in that, The buffer tank (7) is equipped with a heating device and a pH meter. The buffer tank (7) is also equipped with a pH adjustment port, which is connected to the corresponding external alkali delivery pipeline.

5. The microbial-driven iron circulation Fenton oxidation device according to claim 1, characterized in that, The alkali transported by the alkali transport pipeline is sodium hydroxide.

6. The microbial-driven iron circulation Fenton oxidation device according to claim 1, characterized in that, The membrane module (9) is an inorganic membrane module.

7. A microbially driven iron circulation Fenton oxidation device according to claim 6, characterized in that, The inorganic membrane module is a silicon carbide membrane module, and the pore size of the silicon carbide membrane does not exceed 40 nm.

8. A microbially driven iron circulation Fenton oxidation device according to claim 4, characterized in that, Agitators are installed in the acid conditioning tank (1), catalyst mixing tank (2), oxidation reaction tank (3), and neutralization reaction tank (4).

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