An anaerobic biological treatment device and its operation method for sulfate-containing organic wastewater

Abstract

This invention relates to an anaerobic biological treatment device and operating method for sulfate-containing organic wastewater, belonging to the field of industrial wastewater treatment technology. It includes an inlet tank, a main inlet pipe, a main reaction zone, an external circulator, an automatic dosing device, and a nitrate-containing wastewater storage tank. The inlet tank is connected to one end of the main inlet pipe via a second connecting pipe, and the other end of the main inlet pipe is connected to a water distributor located in the main reaction zone. The main reaction zone is connected to the external circulator via a first connecting pipe, and the external circulator is connected to the main inlet pipe via a third connecting pipe. An automatic dosing device is installed at the top of the external circulator, and the nitrate-containing wastewater storage tank is connected to the external circulator via a fourth connecting pipe. An aeration head is installed at the bottom of the inner cavity of the external circulator. This invention separates the aeration zone and the main reaction zone, avoiding sludge leakage caused by direct aeration, maintaining the stability of the anaerobic system, and features a simple structure, adjustable parameters, and a wide range of applications.

Description

Technical Field

[0001] This invention relates to the field of industrial wastewater treatment technology, specifically to an anaerobic biological treatment device and operating method for sulfate-containing organic wastewater. Background Technology

[0002] Industries such as petrochemicals, pharmaceuticals, printing and dyeing, mining, and food processing generate large amounts of sulfate wastewater during production, characterized by high sulfate concentrations and high chemical oxygen demand (COD). Biological methods are widely used in industrial wastewater treatment due to their simplicity and low operating costs. Compared to aerobic biological methods, anaerobic biological methods require no aeration, have lower operating costs, and offer advantages such as high organic loading, low sludge production, generation of secondary energy (CH4), and resistance to shock loads, making them more suitable for treating high-COD wastewater. However, under anaerobic conditions, high concentrations of sulfate in the wastewater convert to sulfides, inhibiting the activity of methanogenic and acidogenic anaerobic bacteria, reducing organic matter removal efficiency and methane production. Excessive sulfide levels can even lead to system collapse. Controlling sulfate reduction is crucial for improving the performance of anaerobic treatment of sulfate-containing organic wastewater. To address this, researchers have proposed methods such as adjusting pH, modifying the influent carbon-sulfur ratio, creating a microaerobic environment, and adding reagents (such as FeCl3, NaNO3, and MgO2). However, methods such as adjusting pH, modifying the influent carbon-sulfur ratio, and adding chemicals often require large amounts of reagents, which are not only costly but also increase the salinity or organic matter concentration of the wastewater, adversely affecting subsequent treatment units. Direct microaeration has limited effect on improving anaerobic treatment, and it also greatly disturbs the sludge, easily causing sludge runoff.

[0003] Therefore, how to provide an anaerobic biological treatment device and operation method for sulfate-containing organic wastewater is one of the technical problems that urgently need to be solved in this field. Summary of the Invention

[0004] The technical problem solved by this invention is to overcome the shortcomings of the prior art and provide an anaerobic biological treatment device and operation method for sulfate-containing organic wastewater. The aeration zone and the main reaction zone are separated, which can avoid sludge runoff caused by direct aeration and maintain the stability of the anaerobic system. It has the characteristics of simple structure, adjustable parameters, and wide application range.

[0005] To achieve the above objectives, the present invention provides an anaerobic biological treatment device for sulfate-containing organic wastewater, comprising: an inlet tank, a main inlet pipe, a main reaction zone, an external circulator, an automatic dosing device, and a nitrate-containing wastewater storage tank; wherein, the inlet tank is connected to one end of the main inlet pipe via a second connecting pipe, and the other end of the main inlet pipe is connected to a water distributor located in the main reaction zone, for distributing wastewater into the main reaction zone through the water distributor; the main reaction zone is connected to the external circulator via a first connecting pipe, and the external circulator is connected to the main inlet pipe via a third connecting pipe, for forming a circulation between the main reaction zone and the external circulator; an automatic dosing device is provided at the top of the external circulator, and the nitrate-containing wastewater storage tank is connected to the external circulator via a fourth connecting pipe, the automatic dosing device and the nitrate-containing wastewater storage tank being used to provide nitrates; an aeration head is provided at the bottom of the inner cavity of the external circulator.

[0006] Furthermore, the main reaction zone is covered with a water bath heating layer, the bottom of the side wall of the water bath heating layer is connected to a water bath heating inlet pipe, and the top of the side wall of the water bath heating layer is connected to a water bath heating outlet pipe.

[0007] Furthermore, a three-phase separator is provided at the top of the main reaction zone, and a main reaction zone outlet pipe is provided on one side of the three-phase separator.

[0008] Furthermore, the inner cavity at the top of the external circulator is divided into a dosing zone and an exhaust zone by a partition. The dosing zone corresponds to the position of the automatic dosing device, and the exhaust zone is connected to a gas purifier through an exhaust pipe.

[0009] Furthermore, the bottom of the external circulator is provided with an inclined return port, which is connected to the third connecting pipe.

[0010] Furthermore, a first valve and a first inlet pump are sequentially installed on the second connecting pipe along the water flow direction.

[0011] Furthermore, a third valve, a reflux pump, and a fourth valve are sequentially installed on the third connecting pipe along the water flow direction.

[0012] Furthermore, a second valve and a second water inlet pump are sequentially installed on the fourth connecting pipe along the water flow direction.

[0013] Furthermore, a check valve is provided on the first connecting pipe.

[0014] An operation method for an anaerobic biological treatment device for sulfate-containing organic wastewater includes: storing the sulfate-containing organic wastewater in an inlet tank; injecting hot water at 30-40℃ into a water bath heating layer to maintain a constant temperature in the anaerobic reactor; opening the first valve, the first inlet pump, and the check valve, allowing the wastewater to enter the main reaction zone through a distributor; when the water level rises to the height of the connecting pipe, the wastewater enters the external circulator; opening the second valve, the second inlet pump, and / or the automatic dosing device; when the water level reaches 1 / 4 of the height of the external circulator, starting the aeration pump; under atmospheric pressure, the water levels in the main reaction zone and the external circulator are equal; when the water level rises to the outlet pipe of the main reaction zone, opening the third and fourth valves, starting the return pump, and recirculating the wastewater internally; as the influent volume increases, the treated effluent is discharged through the outlet pipe of the main reaction zone; the biogas generated in the main reaction zone is collected after passing through a three-phase separator; the exhaust gas generated by the aeration of the external circulator accumulates in the exhaust zone, and under a certain pressure, it is discharged into the atmosphere after absorbing H2S through a gas purifier.

[0015] The beneficial effects of this invention are as follows:

[0016] This invention enhances the treatment effect of sulfate-containing organic wastewater by synergistically inhibiting sulfate reduction during anaerobic treatment with microaerobic nitrate. When sulfate and nitrate ions coexist, anaerobic microorganisms preferentially use nitrate as an electron acceptor. The addition of nitrate stimulates the growth of denitrifying bacteria in the anaerobic biological system, effectively competitively inhibiting sulfate-reducing bacteria and suppressing their activity. Furthermore, the nitrate reduction process generates alkalinity, raising the system pH, and converting H2S generated by the sulfur reduction reaction into HS-H2S. - and S 2- This reduces the inhibitory effect of sulfides on microorganisms. Creating a microaerobic environment can also inhibit the activity of sulfate-reducing bacteria, while aeration can reduce the partial pressure of hydrogen sulfide in the liquid phase, thus lowering its concentration. The synergistic effect of microaerobic and nitrate can reduce the dosage of nitrate reagents and enhance the strengthening effect of microaerobic alone. The device of this invention separates the aeration zone and the main reaction zone, which can avoid sludge leakage caused by direct aeration, maintain the stability of the anaerobic system, and has the characteristics of simple structure, adjustable parameters, and wide application range. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the present invention.

[0018] In the figure:

[0019] 1-Inlet tank, 2-First valve, 3-Second connecting pipe, 4-First inlet pump, 5-Main inlet pipe, 6-Water distributor, 7-Water bath heating inlet pipe, 8-Water bath heating layer, 9-Main reaction zone, 10-Water bath heating outlet pipe, 11-Main reaction zone outlet pipe, 12-Three-phase separator, 13-First connecting pipe, 14-Check valve, 15-External circulator, 16-Dosing area, 17-Exhaust area, 18-Dosing port, 19-Automatic dosing device, 20-Exhaust pipe, 21-Gas purifier, 22-Aeration pump, 23-Aeration head, 24-Nitrate-containing wastewater storage tank, 25-Second valve, 26-Fourth connecting pipe, 27-Second inlet pump, 28-Return port, 29-Third connecting pipe, 30-Third valve, 31-Return pump, 32-Fourth valve. Detailed Implementation

[0020] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0022] In this application, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0023] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0024] Furthermore, the terms "installation," "setup," "equipped with," "connection," "linking," and "socketing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0025] like Figure 1 As shown, this invention provides an anaerobic biological treatment device for sulfate-containing organic wastewater, comprising: an inlet tank 1, a main inlet pipe 5, a main reaction zone 9, an external circulator 15, an automatic dosing device 19, and a nitrate-containing wastewater storage tank 24; wherein, the inlet tank 1 is connected to one end of the main inlet pipe 5 via a second connecting pipe 3, and the other end of the main inlet pipe 5 is connected to a water distributor 6 disposed in the main reaction zone 9, for conveying wastewater into the main reaction zone 9 through the water distributor 6; the main reaction zone 9 is connected to the external circulator 15 via a first connecting pipe 13, and the external circulator 15 is connected to the main inlet pipe 5 via a third connecting pipe 29, for connecting the main reaction zone 9 with the external circulator 15. A circulation system is formed; the top of the external circulator 15 is equipped with a dosing port 18, and the automatic dosing device 19 is located above the dosing port 18. The nitrate-containing wastewater storage tank 24 is connected to the external circulator 15 through a fourth connecting pipe 26. The automatic dosing device 19 and the nitrate-containing wastewater inlet tank 24 are used to provide nitrates to inhibit sulfate activity and control the amount of nitrate added. An aeration head 23 is provided at the bottom of the inner cavity of the external circulator 15. The aeration head 23 is connected to an aeration pump 22 through a pipeline. The aeration head 23 at the bottom of the external circulator 15 provides oxygen to the internal return water, reduces the concentration of sulfides in the aqueous phase, and also acts as a stirrer to accelerate the dissolution of the solid reagents in the automatic dosing device 19. The wastewater NO3 in the nitrate-containing wastewater storage tank 24 - -N concentration should be higher than 150 mg / L. Aeration pump 22 controls the dissolved oxygen in external circulator 15, with dissolved oxygen concentration controlled at 0.6–0.7 mg / L. Water bath heating layer 8 temperature is controlled at 30–40℃. The sludge layer height in main reaction zone 9 should be 1 / 4 to 1 / 2 of the total height of main reaction zone 9.

[0026] To further optimize the technical solution, the main reaction zone 9 is covered with a water bath heating layer 8. The bottom end of the side wall of the water bath heating layer 8 is connected to a water bath heating inlet pipe 7, and the top end of the side wall of the water bath heating layer 8 is connected to a water bath heating outlet pipe 10.

[0027] To further optimize the technical solution, a three-phase separator 12 is provided at the top of the main reaction zone 9, and a main reaction zone water outlet pipe 11 is provided on one side of the three-phase separator 12.

[0028] To further optimize the technical solution, the inner cavity at the top of the external circulator 15 is divided into a dosing zone 16 and an exhaust zone 17 by a partition. The dosing zone 16 corresponds to the position of the automatic dosing device 19. The exhaust zone 16 is connected to a gas purifier 21 via an exhaust pipe 20, which is used to absorb hydrogen sulfide gas released during the aeration process, thereby achieving gas purification. The width of the exhaust zone 17 at the top of the external circulator 15 is 2-50 cm wider than the width at the bottom. The absorbent for the gas purifier 21 is either a 2 mol / L NaOH solution or a Ca(OH)2 solution, preferably a NaOH solution.

[0029] To further optimize the technical solution, the bottom of the external circulator 15 is provided with an inclined return port 28, which is connected to the third connecting pipe 29. The chamfer of the inclined return port is 50° to 75°.

[0030] To further optimize the technical solution, the second connecting pipe 3 is provided with a first valve 2 and a first water inlet pump 4 in sequence along the water flow direction.

[0031] To further optimize the technical solution, a third valve 30, a reflux pump 31, and a fourth valve 32 are sequentially installed on the third connecting pipe 29 along the water flow direction. The reflux pump 31 controls the reflux ratio and is used to adjust the dissolved oxygen in the main reaction zone 9. The flow rate of the reflux pump 31 should be 1 to 2 times the flow rate of the first inlet pump 4, preferably 1.

[0032] To further optimize the technical solution, the fourth connecting pipe 26 is provided with a second valve 25 and a second water inlet pump 27 in sequence along the water flow direction.

[0033] To further optimize the technical solution, a check valve 14 is provided on the first connecting pipe 13.

[0034] The nitrate used in the automatic dosing device 28 is either KNO3 or NaNO3, and the system concentration is 100-200 mg NO3. - -N / L dosage. When nitrate-containing wastewater cannot completely replace the reagent, the dosage of the reagent added by the automatic dosing device 19 is calculated according to formula (1):

[0035] q m =(q v1 +qv2 C1-q v2 ·C2 (1)

[0036] Where q m q represents the mass flow rate of the reagent, in mg / h. v1 and q v2 C1 and C2 are the volumetric flow rates of the first inlet pump 4 and the second inlet pump 27, respectively, in L / h; C1 and C2 are the nitrate nitrogen concentrations added to the system and the nitrate nitrogen concentrations in the nitrate wastewater storage tank 24, respectively, in mg / L.

[0037] When the nitrate-containing wastewater completely replaces the reagent, the automatic dosing device 19 is turned off, and the flow rate of the second inlet pump 27 is calculated according to formula (2):

[0038] qv2=qv1·C1 / (C2-C1) (2)

[0039] When the wastewater does not contain nitrates, the dosage of the reagent in the automatic dosing device 28 is calculated according to formula (3):

[0040] q m =q v1 ·C1 (3).

[0041] This invention also provides an operation method for an anaerobic biological treatment device for sulfate-containing organic wastewater, comprising: storing sulfate-containing organic wastewater in an inlet tank; injecting hot water at 30-40℃ into a water bath heating layer to maintain a constant temperature in the anaerobic reactor; opening the first valve, the first inlet pump, and the check valve, allowing the wastewater to enter the main reaction zone through a distributor; when the water level rises to the height of the connecting pipe, the wastewater enters the external circulator; opening the second valve, the second inlet pump, and / or the automatic dosing device; when the water level reaches 1 / 4 of the height of the external circulator, starting the aeration pump; under atmospheric pressure, the water levels in the main reaction zone and the external circulator are equal; when the water level rises to the outlet pipe of the main reaction zone, opening the third and fourth valves, starting the return pump, and recirculating the wastewater internally; as the inflow increases, the treated effluent is discharged through the outlet pipe of the main reaction zone; the biogas generated in the main reaction zone is collected after passing through a three-phase separator; the exhaust gas generated by the aeration of the external circulator accumulates in the exhaust zone, and under a certain pressure, it is discharged into the atmosphere after absorbing H2S through a gas purifier.

[0042] This invention enhances the treatment effect of sulfate-containing organic wastewater by synergistically inhibiting sulfate reduction during anaerobic treatment with microaerobic nitrate. When sulfate and nitrate ions coexist, anaerobic microorganisms preferentially use nitrate as an electron acceptor. The addition of nitrate stimulates the growth of denitrifying bacteria in the anaerobic biological system, effectively competitively inhibiting sulfate-reducing bacteria and suppressing their activity. Furthermore, the nitrate reduction process generates alkalinity, raising the system pH, and converting H2S generated by the sulfur reduction reaction into HS-H2S. - and S 2-This reduces the inhibitory effect of sulfides on microorganisms. Creating a microaerobic environment can also inhibit the activity of sulfate-reducing bacteria, while aeration can reduce the partial pressure of hydrogen sulfide in the liquid phase, thus lowering its concentration. The synergistic effect of microaerobic and nitrate can reduce the dosage of nitrate reagents and enhance the strengthening effect of microaerobic alone. The device of this invention separates the aeration zone and the main reaction zone, which can avoid sludge leakage caused by direct aeration, maintain the stability of the anaerobic system, and has the characteristics of simple structure, adjustable parameters, and wide application range.

[0043] Example 1

[0044] When there is no nitrate-containing wastewater, the reagents are added entirely by the automatic dosing device 19. Sulfate-containing organic wastewater is stored in the inlet tank 1, and hot water at 30-40℃ is injected into the water bath heating layer 25 to maintain a constant temperature in the anaerobic reactor. The first valve 2, the first inlet pump 4, and the check valve 14 are opened, and the wastewater enters the main reaction zone 9 through the distributor 6. When the water level rises to the height of the first connecting pipe 13, the wastewater enters the external circulator 15, and the automatic dosing device 19 is activated. When the water level reaches 1 / 4 of the height of the external circulator 15, the aeration pump 22 is activated. Under atmospheric pressure, the water levels in the main reaction zone 9 and the external circulator 15 are equal. When the water level rises to the main reaction zone outlet pipe 11, the third valve 30 and the fourth valve 32 are opened, and the return pump 31 is activated, allowing the wastewater to circulate internally. As the inflow increases, the treated effluent is discharged through the main reaction zone outlet pipe 11. The biogas produced in the main reaction zone 9 is collected after passing through the three-phase separator 12. The exhaust gas generated by the external circulator 15 aeration is collected in the exhaust zone 17, and after being absorbed by the gas purifier 21 under a certain pressure, it is discharged into the atmosphere.

[0045] Example 2

[0046] When nitrate-containing wastewater can replace part of the reagents, the automatic dosing device 19 and the second inlet pump 27 need to be turned on. Sulfate-containing organic wastewater is stored in the inlet tank 1, and hot water at 30-40℃ is injected into the water bath heating layer 25 to maintain a constant temperature in the anaerobic reactor. The first valve 2, the first inlet pump 4, and the check valve 14 are opened, and the wastewater enters the main reaction zone 9 through the distributor 6. Nitrate-containing wastewater is stored in the nitrate-containing wastewater storage tank 24. When the liquid level in the main reaction zone 9 reaches the height of the first connecting pipe 13, the second valve 25, the second inlet pump 27, and the automatic dosing device 19 are opened. When the liquid level reaches 1 / 4 of the height of the external circulator 15, the aeration pump 22 is turned on. Under atmospheric pressure, the liquid levels in the main reaction zone 9 and the external circulator 15 are equal. When the liquid level rises to the outlet pipe 11 of the main reaction zone, the third valve 30 and the fourth valve 32 are opened, and the reflux pump 31 is activated, initiating internal wastewater circulation. As the influent volume increases, the treated effluent is discharged through the outlet pipe 11 of the main reaction zone. The biogas produced in the main reaction zone 9 is collected after passing through the three-phase separator 12. The waste gas generated by the aeration in the external circulator 15 accumulates in the exhaust zone 17 and, under certain pressure, is discharged into the atmosphere after H2S is absorbed by the gas purifier 21.

[0047] Example 3

[0048] When nitrates in the nitrate-containing wastewater can completely replace the reagents, the automatic dosing device 19 is turned off. Sulfate-containing organic wastewater is stored in the inlet tank 1, and hot water at 30-40℃ is injected into the water bath heating layer 25 to maintain a constant temperature in the anaerobic reactor. The first valve 2, the first inlet pump 4, and the check valve 14 are opened, and the wastewater enters the main reaction zone 9 through the distributor 6. The second valve 25 and the second inlet pump 27 are opened to pump the nitrate-containing wastewater stored in the nitrate-containing wastewater storage tank 24 into the external circulator 15. When the liquid level reaches 1 / 4 of the height of the external circulator 15, the aeration pump 22 is turned on. Under atmospheric pressure, the liquid levels in the main reaction zone 9 and the external circulator 15 are equal. When the liquid level rises to the main reaction zone outlet pipe 11, the third valve 30 and the fourth valve 32 are opened, and the return pump 31 is turned on, allowing the wastewater to circulate internally. As the inflow increases, the treated effluent is discharged through the main reaction zone outlet pipe 11. The biogas produced in the main reaction zone 9 is collected after passing through the three-phase separator 12. The waste gas generated by the aeration of the external circulator 15 is collected in the exhaust zone 17, and after being absorbed by the gas purifier 21 under a certain pressure, it is discharged into the atmosphere.

[0049] This invention can reduce anaerobic sulfate reduction and sulfide formation through micro-aerobic nitrate synergy, thereby enhancing the performance of anaerobic biological treatment of sulfate organic wastewater, achieving a COD removal rate of over 90%. The reactor is equipped with an external circulator that integrates reagent preparation, oxygenation, and liquid hydrogen sulfide stripping functions, featuring a simple structure and wide applicability.

[0050] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the technical scope of the present invention. Therefore, any minor modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. An anaerobic biological treatment device for sulfate-containing organic wastewater, characterized in that, include: The system comprises an inlet tank, a main inlet pipe, a main reaction zone, an external circulator, an automatic dosing device, and a nitrate-containing wastewater storage tank. The inlet tank is connected to one end of the main inlet pipe via a second connecting pipe, and the other end of the main inlet pipe is connected to a water distributor located within the main reaction zone, used to deliver wastewater into the main reaction zone through the water distributor. The main reaction zone is connected to the external circulator via a first connecting pipe, and the external circulator is connected to the main inlet pipe via a third connecting pipe, used to create a circulation system between the main reaction zone and the external circulator. An automatic dosing device is installed at the top of the external circulator, and the nitrate-containing wastewater storage tank is connected to the external circulator via a fourth connecting pipe. The automatic dosing device and the nitrate-containing wastewater storage tank are used to provide nitrates. An aeration head is installed at the bottom of the inner cavity of the external circulator. The inner cavity at the top of the external circulator is divided into a dosing zone and an exhaust zone by a partition. The dosing zone corresponds to the position of the automatic dosing device, and the exhaust zone is connected to a gas purifier through an exhaust pipe.

2. The anaerobic biological treatment device for sulfate-containing organic wastewater as described in claim 1, characterized in that, The main reaction zone is covered by a water bath heating layer. The bottom of the side wall of the water bath heating layer is connected to a water bath heating inlet pipe, and the top of the side wall of the water bath heating layer is connected to a water bath heating outlet pipe.

3. An anaerobic biological treatment device for sulfate-containing organic wastewater as described in claim 1 or 2, characterized in that, A three-phase separator is installed at the top of the main reaction zone, and a main reaction zone outlet pipe is installed on one side of the three-phase separator.

4. The anaerobic biological treatment device for sulfate-containing organic wastewater as described in claim 1, characterized in that, The bottom of the external circulator is provided with an inclined return port, which is connected to the third connecting pipe.

5. The anaerobic biological treatment device for sulfate-containing organic wastewater as described in claim 1, characterized in that, The second connecting pipe is equipped with a first valve and a first inlet pump in sequence along the water flow direction.

6. The anaerobic biological treatment device for sulfate-containing organic wastewater as described in claim 1, characterized in that, The third connecting pipe is equipped with a third valve, a reflux pump, and a fourth valve in sequence along the water flow direction.

7. The anaerobic biological treatment device for sulfate-containing organic wastewater as described in claim 1, characterized in that, The fourth connecting pipe is equipped with a second valve and a second water inlet pump in sequence along the water flow direction.

8. The anaerobic biological treatment device for sulfate-containing organic wastewater as described in claim 1, characterized in that, The first connecting pipe is equipped with a check valve.

9. The method for operating an anaerobic biological treatment device for sulfate-containing organic wastewater as described in any one of claims 1-8, characterized in that, include: Sulfate-containing organic wastewater is stored in the inlet tank. Hot water at 30-40℃ is injected into the water bath heating layer to maintain a constant temperature in the main reaction zone. The first valve, first inlet pump, and check valve are opened, allowing wastewater to enter the main reaction zone through the distributor. When the water level rises to the height of the first connecting pipe, the wastewater enters the external circulator. The second valve, second inlet pump, and / or automatic dosing device are then opened. When the water level reaches 1 / 4 of the height of the external circulator, the aeration pump is activated. Under atmospheric pressure, the water levels in the main reaction zone and the external circulator are equal. When the water level rises to the outlet pipe of the main reaction zone, the third and fourth valves are opened, and the return pump is activated, initiating internal wastewater circulation. As the inflow increases, the treated effluent is discharged through the outlet pipe of the main reaction zone. The biogas generated in the main reaction zone is collected after passing through a three-phase separator. The exhaust gas generated by the external circulator aeration system accumulates in the exhaust zone and, under certain pressure, is discharged into the atmosphere after H2S absorption by a gas purifier.

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