Anaerobic sludge treatment and recovery system

Abstract

The utility model discloses an anaerobic sludge treatment recovery system relates to wastewater treatment technical field, including anaerobic reactor, anaerobic sedimentation tank and membrane bioreactor, and the water outlet of anaerobic sedimentation tank is communicated with anaerobic reactor, and anaerobic sedimentation tank is equipped with sludge outlet and wastewater outlet, and the import of sludge outlet and anaerobic reactor is communicated through first sludge conveying pipe, and membrane bioreactor is communicated with wastewater outlet, and membrane bioreactor is used to separate into thick liquid and clear liquid with the water of going in, and the import of the thick liquid outlet of membrane bioreactor and anaerobic reactor is communicated through second sludge conveying pipe. The application recovers anaerobic sludge to anaerobic reactor as far as possible, maintains the sludge concentration in anaerobic reactor at higher level, and high sludge concentration makes the gas production of anaerobic reactor increase, guarantees the suspended solids concentration of effluent at very low level through membrane bioreactor, and improves the sludge problem of anaerobic reactor as a whole.

Description

Technical Field

[0001] This utility model relates to the field of wastewater treatment technology, and in particular to an anaerobic sludge treatment and recycling system. Background Technology

[0002] The process of producing fuel ethanol from the tail gas of silicon-manganese alloys through biological fermentation generates organic wastewater with high COD and high ammonia nitrogen levels. COD, short for Chemical Oxygen Demand, is a crucial indicator for assessing water pollution levels. Anaerobic biological treatment is the core of wastewater treatment, with anaerobic sludge converting organic matter in the wastewater into methane.

[0003] In anaerobic biological treatment, the water quality is mixed in an equalization tank. Wastewater enters the treatment zone from the distributor at the bottom of the anaerobic reactor via an anaerobic influent pump. This wastewater entering the anaerobic reactor is referred to as the influent. In the treatment zone of the anaerobic reactor, the influent mixes and reacts with high-concentration granular sludge, where over 90% of the organic matter is decomposed into biogas. The reacted wastewater is then separated by a three-phase separator, and the separated sludge is returned to the bottom of the anaerobic reactor. The anaerobic reactor itself is also equipped with a circulation pipe, one purpose of which is to dilute the high COD concentration of the influent.

[0004] However, when the influent flow rate increases or the influent COD fluctuates, the anaerobic sludge load increases, the number of microorganisms in the anaerobic reactor increases, which in turn causes the sludge to deteriorate, the sludge settling ability to decrease, and ultimately causes sludge leakage, which urgently needs to be improved. Utility Model Content

[0005] To address the aforementioned problems, this application provides an anaerobic sludge treatment and recycling system.

[0006] This application provides an anaerobic sludge treatment and recycling system, including an anaerobic reactor, an anaerobic sedimentation tank, and a membrane bioreactor. The anaerobic sedimentation tank is connected to the outlet of the anaerobic reactor and has a sludge outlet and a wastewater outlet. The sludge outlet is connected to the inlet of the anaerobic reactor through a first sludge conveying pipe. The membrane bioreactor is connected to the wastewater outlet and is used to separate the influent into concentrated liquid and clear liquid. The concentrated liquid outlet of the membrane bioreactor is connected to the inlet of the anaerobic reactor through a second sludge conveying pipe.

[0007] In some embodiments, the membrane bioreactor includes a shell and an MBR membrane element. The shell has an inlet connected to a wastewater outlet, a concentrate outlet, and a clear liquid outlet. The MBR membrane element includes a frame and an MBR membrane in an enclosed area connected to the frame. Multiple MBR membrane elements are arranged opposite each other. The multiple MBR membrane elements are sequentially and parallelly installed inside the shell and located between the inlet and the clear liquid outlet.

[0008] In some embodiments, the housing includes a main housing and a sealing cap. The main housing has an opening on the top side. Multiple MBR membrane elements are installed sequentially and parallelly within the main housing. The frame is detachably connected to the main housing. The main housing has an observation window. The sealing cap is detachably connected to the main housing at the opening.

[0009] In some embodiments, the anaerobic sedimentation tank is equipped with an inclined plate settler, and the anaerobic sedimentation tank is equipped with an overflow weir opposite to the inclined plate settler. The wastewater outlet is located on the side of the overflow weir away from the inclined plate settler.

[0010] In some implementations, the anaerobic sludge treatment and recovery system also includes an equalization tank for receiving upstream water, with the outlet of the equalization tank connected to the inlet of the anaerobic reactor.

[0011] In some implementations, the outlet of the equalization tank is connected to the inlet of the anaerobic reactor via an inlet pipe, which is equipped with at least one of a flow meter, a pH meter, and an OPR meter.

[0012] In some embodiments, the anaerobic sludge treatment and recovery system further includes a gas-liquid separator connected to the gas outlet of the anaerobic reactor, and the liquid outlet of the gas-liquid separator connected to the inlet of the anaerobic reactor via a third sludge conveying pipe.

[0013] In some implementations, the gas outlet of the gas-liquid separator is connected to a biogas pressure stabilizing cabinet.

[0014] In some implementations, the anaerobic sludge treatment and recovery system also includes an AO tank, which is connected to the clear liquid outlet of the membrane bioreactor.

[0015] In some implementations, an online sludge concentration meter is installed in the connecting pipe between the AO tank and the clear liquid outlet.

[0016] The beneficial effects of this application are as follows: It provides an anaerobic sludge treatment and recovery system, including an anaerobic reactor, an anaerobic sedimentation tank, and a membrane bioreactor. Upstream organic wastewater enters the anaerobic reactor through the inlet. The wastewater is thoroughly mixed and reacted with the anaerobic sludge within the reactor. The organic matter in the wastewater is decomposed into biogas, which is output from the vent of the anaerobic reactor. The sludge-water mixture is separated by a three-phase separator within the anaerobic reactor, with the anaerobic sludge returning to the bottom of the reactor. The treated wastewater enters the anaerobic sedimentation tank, where most of the anaerobic sludge settles and is further returned to the anaerobic reactor via a first sludge conveying pipe. Wastewater containing a small amount of anaerobic sludge is sent from the wastewater outlet of the anaerobic sedimentation tank to the membrane bioreactor, where it is separated by the MBR membrane. The process produces a concentrated sludge solution containing a relatively large amount of anaerobic sludge and a clarified sludge solution containing a relatively small amount of anaerobic sludge. The concentrated sludge solution is returned to the anaerobic reactor through a second sludge conveying pipe, while the clarified sludge solution can be further processed. By applying the scheme described in this application, anaerobic sludge is recycled back into the anaerobic reactor as much as possible, maintaining a high sludge concentration within the reactor. The MLSS concentration in the anaerobic reactor can be controlled to be consistently greater than 40 g / L. The high sludge concentration increases the biogas production of the anaerobic reactor by 15% to 20%. The membrane bioreactor ensures that the suspended solids concentration in the effluent is kept at an extremely low level, controlling the SS concentration in the effluent to be less than 5 mg / L. Overall, this improves the sludge problem in the anaerobic reactor, thereby increasing the treatment capacity of the anaerobic reactor. While reducing production costs, it can generate more biogas for subsequent processes. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model.

[0018] Figure 1 This is a schematic diagram of an anaerobic sludge treatment and recycling system provided in this application.

[0019] Attached diagram labels: 100-Anaerobic reactor, 200-Anaerobic sedimentation tank, 210-First sludge conveying pipe, 300-Membrane bioreactor, 310-Second sludge conveying pipe, 400-AO tank, 500-Gas-liquid separator, 510-Third sludge conveying pipe, 600-Equalization tank, 610-Inlet pipe. Detailed Implementation

[0020] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0021] Furthermore, reference numerals and / or reference letters may be repeated in different examples in this application. Such repetition is for simplification and clarity purposes and does not in itself indicate a relationship between the various embodiments and / or settings discussed. In addition, this application provides examples of various specific processes and materials; however, those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0022] Please refer to Figure 1 This application discloses an anaerobic sludge treatment and recycling system, including an anaerobic reactor 100, an anaerobic sedimentation tank 200, and a membrane bioreactor 300.

[0023] As the core of wastewater treatment, the anaerobic reactor 100 receives upstream organic wastewater through its inlet. The wastewater is thoroughly mixed and reacted with anaerobic sludge within the reactor, where organic matter is decomposed into biogas. This biogas is then output from the vent of the reactor 100. The sludge-water mixture is separated by a three-phase separator within the reactor 100, and the anaerobic sludge returns to the bottom of the reactor. The anaerobic sedimentation tank 200 is connected to the vent of the reactor 100, allowing the treated wastewater to enter.

[0024] Anaerobic sedimentation tank 200 allows most of the anaerobic sludge in the wastewater to settle. Anaerobic sedimentation tank 200 is equipped with a sludge outlet and a wastewater outlet. The sludge outlet is connected to the inlet of anaerobic reactor 100 through a first sludge conveying pipe 210. The settled anaerobic sludge is sent back to anaerobic reactor 100 through the first sludge conveying pipe 210. Membrane bioreactor 300 is connected to the wastewater outlet. Wastewater containing a small amount of anaerobic sludge is sent from the wastewater outlet of anaerobic sedimentation tank 200 to membrane bioreactor 300.

[0025] Wastewater containing a small amount of anaerobic sludge is used as the influent to the membrane bioreactor 300. The influent is separated into concentrated liquid and clarified liquid by the MBR membrane in the membrane bioreactor 300. The concentrated liquid contains a relatively large amount of anaerobic sludge, while the clarified liquid contains a relatively small amount. The anaerobic sludge content in the concentrated liquid is also at a lower level. The clarified liquid is discharged from the clarified liquid outlet of the membrane bioreactor 300, and the concentrated liquid is discharged from the concentrated liquid outlet of the membrane bioreactor 300. The concentrated liquid outlet of the membrane bioreactor 300 is connected to the inlet of the anaerobic reactor 100 through a second sludge conveying pipe 310. The concentrated liquid is returned to the anaerobic reactor 100 through the second sludge conveying pipe 310, while the clarified liquid can be used for further treatment.

[0026] By applying the scheme of this application, anaerobic sludge is recycled into the anaerobic reactor 100 as much as possible, maintaining the sludge concentration in the anaerobic reactor 100 at a high level. In practical applications, the MLSS concentration in the anaerobic reactor 100 can be controlled to be stably greater than 40 g / L. MLSS, also known as mixed liquor suspended solids concentration, is an important indicator of anaerobic sludge performance. By controlling the sludge concentration in the anaerobic reactor 100 to a high level, the gas production of the anaerobic reactor 100 can be increased by 15% to 20%. On the other hand, by applying the scheme of this application, the suspended solids concentration in the effluent is ensured to be at an extremely low level through the membrane bioreactor 300. In practical applications, the SS concentration in the effluent can be controlled to be less than 5 mg / L. SS stands for Suspended Solids.

[0027] In summary, the proposed solution improves the sludge problem of the anaerobic reactor 100 as a whole, thereby increasing the processing capacity of the anaerobic reactor 100. While reducing production costs, it can generate more biogas for subsequent processes.

[0028] In some implementation methods, please refer to Figure 1 The anaerobic sludge treatment and recovery system also includes a gas-liquid separator 500, which is connected to the gas outlet of the anaerobic reactor 100. The liquid outlet of the gas-liquid separator 500 is connected to the inlet of the anaerobic reactor 100 via a third sludge conveying pipe 510. Biogas generated during the anaerobic reaction is output from the gas outlet of the anaerobic reactor 100, carrying a sludge-water mixture. The biogas enters the gas-liquid separator 500, where it separates from the sludge-water mixture. The sludge-water mixture is then sent back to the bottom of the anaerobic reactor 100 via the third sludge conveying pipe 510.

[0029] The separated biogas can be sent to a biogas pressure stabilizing unit, and there is a corresponding connection between the gas outlet of the gas-liquid separator 500 and the biogas pressure stabilizing unit. As a key device for storing, balancing, and controlling biogas flow and pressure, the biogas pressure stabilizing unit plays a vital role in the industrial field.

[0030] In some implementation methods, please refer to Figure 1 The anaerobic sludge treatment and recovery system also includes AO tank 400, which is the core structure of the anaerobic-aerobic biological treatment process in wastewater treatment. AO stands for Anaerobic-Oxic, which is an abbreviation for anaerobic-aerobic process. AO tank 400 is connected to the clear liquid outlet of membrane bioreactor 300. Wastewater treated by membrane bioreactor 300 enters AO tank 400 for further treatment.

[0031] In some implementations, an online sludge concentration meter is installed on the connecting pipe between the AO tank 400 and the clarified liquid outlet. This meter allows for online monitoring of the sludge concentration in the wastewater flowing through the pipe. Because the online sludge concentration meter readings are correlated with the treatment efficiency of the membrane bioreactor 300, poor performance can lead to higher readings on the online sludge concentration meter, facilitating timely on-site inspection and intervention. In actual production, an alarm can be triggered when the online sludge concentration meter reading exceeds 100 mg / L. A corresponding alarm is installed and linked to the online sludge concentration meter; details regarding the alarm settings are not elaborated here.

[0032] In some implementation methods, please refer to Figure 1 The anaerobic sludge treatment and recovery system also includes an equalization tank 600, which receives upstream water. The outlet of the equalization tank 600 is connected to the inlet of the anaerobic reactor 100. After the upstream water is mixed evenly in the equalization tank 600, it is pumped to the bottom of the anaerobic reactor 100 by an anaerobic feed pump. The function of the equalization tank 600 is to homogenize and mix the upstream water, control the COD of the influent to the anaerobic reactor 100 to stabilize, and improve the sludge loss problem.

[0033] In some embodiments, the outlet of the equalization tank 600 is connected to the inlet of the anaerobic reactor 100 via an inlet pipe 610. An anaerobic feed pump is installed in the inlet pipe 610. The inlet pipe 610 is equipped with at least one of a flow meter, a pH meter, and an OPR meter. The pH meter measures the pH value of the influent to the anaerobic reactor 100, and the OPR meter (oxidation-reduction potentiometer) measures the oxidation-reduction potential of the influent to the anaerobic reactor 100. In some schemes, all three devices—flow meter, pH meter, and OPR meter—are installed in the inlet pipe 610 to measure parameters of the influent to the anaerobic reactor 100, making the parameters of the influent to the anaerobic reactor 100 controllable.

[0034] The term "Membrane Bioreactor 300" can also be used interchangeably with "MBR." MBR stands for Membrane Bio-Reactor, a novel water treatment device that combines membrane separation technology with biological treatment. Its core component replaces the traditional secondary sedimentation tank with a membrane module, achieving efficient separation of sludge and water through ultrafiltration / microfiltration technology. In some embodiments, the membrane bioreactor 300 includes a shell and MBR membrane elements. The shell has an inlet connected to a wastewater outlet, a concentrate outlet, and a clarified liquid outlet. The MBR membrane elements include a frame and an MBR membrane in an enclosed area connected to the frame. The MBR membrane refers to a microporous filtration membrane used to achieve efficient separation of mud and water. Multiple MBR membrane elements are arranged opposite each other, and the multiple MBR membrane elements are installed in parallel and spaced apart in sequence inside the shell and between the inlet and the clarified liquid outlet.

[0035] In some embodiments, the housing includes a main housing and a sealing cap. The main housing has an opening on the top side. Multiple MBR membrane elements are installed sequentially and parallelly within the main housing. The frame is detachably connected to the main housing. The main housing has an observation window. The sealing cap is detachably connected to the main housing at the opening.

[0036] The observation window allows monitoring of the MBR membrane's usage and pressure differential. When an individual MBR membrane exhibits severe fouling, the operator can detach the sealing cap from the outer shell, remove the corresponding MBR membrane module from the main shell, replace it with a new one, or use a pre-prepared MBR membrane module, and reinstall it into the main shell. The sealing cap is then reinstalled, completing the replacement of the individual MBR membrane module and allowing the membrane bioreactor 300 to continue operating normally.

[0037] In some implementations, the MBR membrane element and the main shell can be connected by a slot. The main shell has multiple slots, each corresponding to a different MBR membrane element to be installed. The MBR membrane element passes through the slot, and the multiple slots define a precise installation position for each MBR membrane element.

[0038] With multiple MBR membrane modules installed sequentially and in parallel intervals within the housing, the spacing between the MBR membranes of two adjacent MBR membrane modules can be increased to 15 mm.

[0039] Regarding MBR membranes, a hydrophilic and oleophobic coating can be applied to the surface of the membrane fibers, which has a beneficial anti-fouling effect. A possible implementation scheme is PVDF+TiO2, where PVDF refers to polyvinylidene fluoride and TiO2 refers to titanium dioxide. PVDF serves as the matrix material, and titanium dioxide modification improves membrane performance.

[0040] In some embodiments, the anaerobic sedimentation tank 200 is equipped with an inclined plate settler, which allows wastewater and settled sludge to move and separate in the shallow sedimentation layer. The anaerobic sedimentation tank 200 is equipped with an overflow weir opposite the inclined plate settler. The overflow weir is a structure used to control liquid overflow. It maintains the liquid level by restricting the flow of wastewater and ensures that the liquid overflows evenly. The wastewater outlet is located on the side of the overflow weir away from the inclined plate settler. The overflowed wastewater is sent from the waste outlet to the membrane bioreactor 300 for treatment.

[0041] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0042] Although preferred embodiments of the present invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the present invention.

[0043] Obviously, those skilled in the art can make various modifications and variations to this utility model without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this utility model and their equivalents, this utility model also intends to include these modifications and variations.

Claims

1. An anaerobic sludge treatment and recycling system, characterized in that, include: Anaerobic reactor; An anaerobic sedimentation tank is connected to the outlet of the anaerobic reactor. The anaerobic sedimentation tank is provided with a sludge outlet and a wastewater outlet. The sludge outlet is connected to the inlet of the anaerobic reactor through a first sludge conveying pipe. and A membrane bioreactor is connected to the wastewater outlet. The membrane bioreactor is used to separate the influent into concentrated liquid and clear liquid. The concentrated liquid outlet of the membrane bioreactor is connected to the inlet of the anaerobic reactor through a second sludge conveying pipe.

2. The anaerobic sludge treatment and recycling system as described in claim 1, characterized in that, The membrane bioreactor includes: The outer casing has an inlet connected to the wastewater outlet, and the outer casing also has a concentrated liquid outlet and a clarified liquid outlet; and An MBR membrane module includes a frame and an MBR membrane connected to the frame in an enclosed area. Multiple MBR membrane modules are arranged opposite each other and are sequentially and parallelly installed inside the housing and located between the inlet and the clear liquid outlet.

3. The anaerobic sludge treatment and recycling system as described in claim 2, characterized in that, The outer casing includes: The main housing has an opening on the top side. Multiple MBR membrane elements are sequentially and parallelly spaced within the main housing. The frame is detachably connected to the main housing. The main housing has an observation window. A sealing cap is detachably connected to the main shell at the opening.

4. The anaerobic sludge treatment and recycling system as described in claim 1, characterized in that, The anaerobic sedimentation tank is equipped with an inclined plate settler, and the anaerobic sedimentation tank is equipped with an overflow weir opposite to the inclined plate settler. The wastewater outlet is located on the side of the overflow weir away from the inclined plate settler.

5. The anaerobic sludge treatment and recycling system as described in claim 1, characterized in that, The anaerobic sludge treatment and recycling system also includes: An equalization tank is used to receive water from upstream, and the outlet of the equalization tank is connected to the inlet of the anaerobic reactor.

6. The anaerobic sludge treatment and recycling system as described in claim 5, characterized in that, The outlet of the equalization tank is connected to the inlet of the anaerobic reactor via an inlet pipe, and the inlet pipe is equipped with at least one of a flow meter, a pH meter, and an OPR meter.

7. The anaerobic sludge treatment and recycling system according to any one of claims 1-6, characterized in that, The anaerobic sludge treatment and recycling system also includes: A gas-liquid separator is connected to the gas outlet of the anaerobic reactor, and the liquid outlet of the gas-liquid separator is connected to the inlet of the anaerobic reactor through a third sludge conveying pipe.

8. The anaerobic sludge treatment and recycling system as described in claim 7, characterized in that, The outlet of the gas-liquid separator is connected to a biogas pressure stabilizing cabinet.

9. The anaerobic sludge treatment and recycling system as described in claim 7, characterized in that, The anaerobic sludge treatment and recycling system also includes: The AO tank is connected to the clear liquid outlet of the membrane bioreactor.

10. The anaerobic sludge treatment and recycling system as described in claim 9, characterized in that, An online sludge concentration meter is installed in the connecting pipe between the AO tank and the clear liquid outlet.

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