Integrated dynamic membrane bioreactor device for strengthening anaerobic digestion of sludge by lateral flow wall breaking and application of integrated dynamic membrane bioreactor device

Abstract

The invention discloses an integrated dynamic membrane bioreactor device for strengthening anaerobic digestion of sludge by lateral flow wall breaking and application. The integrated dynamic membrane bioreactor device comprises an anaerobic dynamic membrane bioreactor and a sludge electric wall breaking device, the anaerobic dynamic membrane bioreactor adopts a split type and comprises a main reaction zone and a membrane separation zone; the main reaction zone is connected with the membrane separation zone through a sludge pipeline, and a sludge side flow inlet is formed in one side, far away from the membrane separation zone, of the main reaction zone; a sludge side flow outlet is formed in the bottom of the membrane separation area; a water bath heat preservation coil pipe is arranged outside the main reaction zone and the membrane separation zone; and the sludge electric wall breaking device is respectively connected with a sludge side flow outlet of the membrane separation area and a sludge side flow inlet of the main reaction area through a sludge side flow pipeline. The concentrated sludge is subjected to retreatment cell lysis by using the sludge electric wall breaking device, dissolution of organic matters in sludge cells is promoted, the speed limiting steps of cell wall breaking and hydrolytic acidification in the sludge digestion process are broken through, and the anaerobic digestion efficiency of the sludge is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of sludge anaerobic digestion, and relates to an integrated dynamic membrane bioreactor device and application for enhancing sludge anaerobic digestion by side-stream cell wall breaking. Background Art

[0002] When the AnDMBR process is used for sludge anaerobic digestion, the operating concentration can be increased by decoupling the hydraulic retention time and the solid retention time. However, high-concentration sludge is a non-Newtonian fluid with a large viscosity, and the flow pattern and mass transfer in a conventional AnDMBR device are prone to unevenness. As a result, the cell wall breaking and hydrolysis acidification stages are hindered, and studies have shown that this stage is the main rate-limiting step in sludge anaerobic digestion, ultimately reducing the efficiency of the entire reactor.

[0003] Conventional AnDMBR devices generally set up a sludge return pipeline system between the membrane separation area and the main reaction area, and achieve sludge circulation between the two through the suction of a pump. Such devices have many deficiencies. On the one hand, although high sludge concentration operation can be achieved, due to the high sludge concentration and large viscosity, the flow pattern and mass transfer in the reactor are prone to unevenness, thus easily hindering the cell wall breaking and hydrolysis acidification stages. In addition, although the concentrated sludge in the membrane area will return to the main reaction area for further digestion, this process does not break through from the essence of the anaerobic digestion process, and its efficiency is still limited by the rate of the cell wall breaking and hydrolysis acidification steps.

[0004] In order to further improve the efficiency of sludge anaerobic digestion, through in-depth research and analysis, an integrated dynamic membrane bioreactor device for enhancing sludge anaerobic digestion by side-stream cell wall breaking is designed. Summary of the Invention

[0005] Aiming at the problems of high operating concentration in the membrane area and high sludge viscosity existing in the conventional AnDMBR device during operation in the prior art, the purpose of the present invention is to provide an integrated dynamic membrane bioreactor device and application for enhancing sludge anaerobic digestion by side-stream cell wall breaking, which adds a sludge electro cell wall breaking device on the side-stream to reprocess and lyse the returned sludge, promotes the dissolution of intracellular organic matter in the sludge, breaks through the rate-limiting steps of cell wall breaking and hydrolysis acidification in the sludge digestion process, and improves the efficiency of sludge anaerobic digestion.

[0006] To achieve the above purpose, the present invention adopts the following technical solutions:

[0007] The first aspect of the present invention provides an integrated dynamic membrane bioreactor device for enhancing sludge anaerobic digestion by side-stream cell wall breaking, including an anaerobic dynamic membrane bioreactor and a sludge electro cell wall breaking device;

[0008] The anaerobic dynamic membrane bioreactor adopts a split type, which includes a main reaction area and a membrane separation area;

[0009] The main reaction zone is connected to the membrane separation zone through a sludge pipeline, and a sludge side-stream inlet is provided on one side of the main reaction zone away from the membrane separation zone;

[0010] A sludge side-stream outlet is provided at the bottom of the membrane separation zone;

[0011] A water bath heat preservation coil is provided outside the main reaction zone and the membrane separation zone;

[0012] The sludge electro-biological cell disruption device is connected to the sludge side-stream outlet of the membrane separation zone and the sludge side-stream inlet of the main reaction zone respectively through a sludge side-stream pipeline.

[0013] Preferably, sludge pumps are provided on the sludge side-stream pipelines on both sides of the sludge electro-biological cell disruption device.

[0014] Preferably, the volume ratio of the membrane separation zone to the main reaction zone is 1:6 to 1:9.

[0015] Preferably, a sludge inlet is provided on one side of the main reaction zone, a stirrer is provided inside, and a biogas outlet is provided at the top;

[0016] A membrane frame, a membrane module and a biogas circulation pipeline are integrated inside the membrane separation zone. A membrane water outlet and a biogas outlet are provided at the top of the membrane separation zone, and a sludge discharge port is provided at the bottom of the membrane separation zone.

[0017] The second aspect of the present invention provides an application of the integrated dynamic membrane bioreactor device for side-stream disruption enhanced sludge anaerobic digestion as described in the first aspect of the present invention in sludge anaerobic digestion.

[0018] The present invention has the following beneficial effects: 1. By combining an anaerobic dynamic membrane bioreactor with an electro-biological cell disruption device into an integrated equipment, the present invention enables the concentrated digested sludge to be re-circulated into the digestion system after being disrupted, improving the rate of cell disruption and hydrolysis acidification processes during sludge anaerobic digestion, and enabling the disrupted sludge to be digested again, realizing further reduction and resource utilization of sludge. Thus, the digestion efficiency of the entire device is improved, providing guarantee for the long-term efficient operation of the reactor; 2. Compared with conventional AnDMBR devices, the present invention integrates an electro-biological cell disruption device, breaking through the key rate-limiting steps during sludge anaerobic digestion, effectively improving the treatment performance of the system; through the action of high-frequency microwaves, the dissolution of intracellular organic matter and the peeling process of adherent extracellular polymers and cells are strengthened, further reducing the viscosity of sludge, thereby greatly improving the anaerobic digestion efficiency; in terms of VS digestion rate, the equipment of the present invention shows higher stability, and the digestion rate can stably reach more than 45%, the methane production rate is increased to more than 0.5 L / g VS, and the operation effect is long-term stable and reliable, applicable to different types of sludge treatment scenarios and can be promoted; 3. The present invention enhances the anaerobic digestion process of sludge through side-stream cell wall breaking, achieving efficient sludge reduction and resource utilization while improving the anaerobic digestion efficiency. During the sludge treatment process, the concentrated sludge is refluxed to the main reaction zone for re-digestion after electro-mechanical cell wall breaking, improving the utilization efficiency of organic matter, reducing the final sludge discharge of the system, and providing an economical and efficient solution for sludge treatment and disposal. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Other features, objectives, and advantages of the present invention will become more apparent by reading the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0020] Figure 1 It is a schematic structural diagram of the AnDMBR used in the integrated dynamic membrane bioreactor device for side-stream cell wall breaking enhanced anaerobic digestion of sludge according to the present invention;

[0021] Among them, 1 is the main reaction zone; 11 is the sludge inlet; 12 is the side-stream sludge inlet; 2 is the membrane separation zone; 21 is the membrane effluent outlet; 22 is the sludge discharge port; 23 is the side-stream sludge outlet; 3 is the sludge electro-mechanical cell wall breaking device; 31 is the side-stream sludge pipeline; 32 is the sludge pump. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] In order to better understand the above technical solutions of the present invention, the technical solutions of the present invention will be further described below in conjunction with embodiments.

[0023] Combined with Figure 1 As shown, the present invention provides an integrated dynamic membrane bioreactor device for side-stream cell wall breaking enhanced anaerobic digestion of sludge, including an anaerobic dynamic membrane bioreactor and a sludge electro-mechanical cell wall breaking device 3. The anaerobic dynamic membrane bioreactor adopts a split type, which includes a main reaction zone 1 and a membrane separation zone 2; the main reaction zone 1 and the membrane separation zone 2 are connected by a sludge pipeline, and a side-stream sludge inlet 12 is provided on the side of the main reaction zone 1 away from the membrane separation zone 2; a side-stream sludge outlet 23 is provided at the bottom of the membrane separation zone 2; a water bath heat preservation coil is provided outside the main reaction zone 1 and the membrane separation zone 2, and the water bath heat preservation coil is used to maintain the digestion temperature. The sludge electro-mechanical cell wall breaking device 3 is connected to the membrane separation zone 2 and the main reaction zone 1 respectively through a side-stream sludge pipeline 31; the sludge electro-mechanical cell wall breaking device 3 is used to electro-mechanically break the concentrated sludge treated by the membrane separation zone 2 and then return it to the main reaction zone 1. In the present invention, the sludge in the main reaction zone 1 is pumped to the membrane separation zone 2 after anaerobic digestion, and solid-liquid separation is achieved through a dynamic membrane in the membrane separation zone 2. A part of the separated concentrated sludge is discharged, and the other part is pumped to the sludge electro-mechanical cell wall breaking device 3 for electro-mechanical cell wall breaking treatment and circulated to the main reaction zone 1 for re-digestion, breaking through the rate-limiting steps of cell wall breaking and hydrolysis acidification in sludge digestion, improving the anaerobic digestion efficiency of the system, and achieving higher digestion performance than conventional AnDMBR devices.

[0024] Combine Figure 1 As shown, the sludge electrolytic wall-breaking device 3 forms a sludge circulation channel with the main reaction zone 1 and membrane separation zone 2 via sludge sidestream pipes 31. Sludge pumps 32 are installed on the sludge sidestream pipes 31 on both sides of the sludge electrolytic wall-breaking device 3. The sludge electrolytic wall-breaking device 3 transmits electromagnetic waves at a frequency of 10 GHz to 100 GHz, promoting the dissolution of intracellular organic matter and the separation of fixed extracellular polymers from cells, reducing sludge viscosity, and returning the broken sludge to the main reaction zone 1 for further digestion.

[0025] Combine Figure 1 As shown, the main reaction zone 1 has a mud inlet 11 on one side, an internal agitator, and a biogas outlet at the top. The membrane separation zone 2 integrates a detachable membrane frame, a membrane assembly (consisting of multiple flat membranes arranged at equal intervals, with a substrate made of nylon, polyester, or stainless steel mesh), and a biogas circulation pipeline (including an aeration tube assembly below the membrane assembly and a detachable external circulation pipeline connected to the aeration tube assembly). The membrane separation zone 2 has a membrane water outlet 21 and a biogas outlet at the top, and a mud outlet 22 at the bottom.

[0026] Combine Figure 1 As shown, the volume ratio of the membrane separation zone 2 to the main reaction zone 1 is 1:6~1:9. The dynamic membrane solid-liquid separation effect is used to decouple the HRT and SRT, thereby increasing the sludge concentration of the reaction system and maintaining it at 30~60 g / L.

[0027] When the above-mentioned integrated dynamic membrane bioreactor device for side-stream wall breaking to enhance sludge anaerobic digestion is applied to sludge anaerobic digestion, the VS digestion rate of the system can reach more than 45%, and the methane yield can reach more than 0.5 L / g VS. During the sludge anaerobic digestion process, the sludge flow rate from the main reaction zone 1 to the membrane zone is Q, and the side-stream sludge flow rates from the membrane separation zone 2 to the sludge electric wall breaking device 3 and from the sludge electric wall breaking device 3 to the main reaction zone 1 are both 0.5~0.75Q.

[0028] Example 1

[0029] In this embodiment, an integrated dynamic membrane bioreactor device for enhancing anaerobic digestion of sludge by side-stream wall breaking of the present invention is adopted, which includes an anaerobic dynamic membrane bioreactor and a sludge electric wall breaking device. The anaerobic dynamic membrane bioreactor adopts a split type, with a main reactant volume of 625L and a membrane separation zone volume of 75L. The membrane separation zone integrates a membrane frame, 5 flat membranes arranged at equal intervals, and a biogas circulation pipeline. The sludge electric wall breaking device is connected to the membrane separation zone and the main reaction zone respectively through a sludge side-stream pipeline, and a sludge pump is provided on the sludge side-stream pipeline.

[0030] During the anaerobic digestion of sludge by the integrated dynamic membrane bioreactor device with side-stream cell disruption to enhance sludge anaerobic digestion, the influent sludge concentration is 49 g / L. The sludge is digested in the main reaction zone and then pumped to the membrane separation zone. After the separation of sludge and water in the membrane separation zone, a part of the concentrated sludge is discharged, and the other part is recycled to the sludge electro-disruption device for electro-disruption treatment. The sludge electro-disruption device emits electromagnetic waves with a frequency of 30 GHz to promote the dissolution of intracellular organic matter and the detachment of attached extracellular polymers from cells, reduce the sludge viscosity. The disrupted sludge returns to the main reaction zone for re-digestion. Finally, the VS digestion rate of the entire system even reaches 48.3%, and the methane production rate increases to 0.525 L / g VS. The sludge flow rate from the main reaction zone to the membrane zone is Q, and the side-stream sludge flow rates from the membrane zone to the side-stream cell disruption device and from the disruption device to the main reaction zone are both 0.75Q.

[0031] Example 2

[0032] Most of this example is the same as Example 1. The difference is that the volume of the main reaction chamber of the anaerobic dynamic membrane bioreactor is 625 L, the volume of the membrane separation zone is 100 L, and there are 8 equally spaced flat membranes in the membrane separation zone. When treating sludge by anaerobic digestion, the VS digestion rate of the entire system can reach 56.9%, and the biogas production rate can reach 0.81 L / g VS.

[0033] In summary, based on the sludge anaerobic digestion process with sludge cell disruption, the present invention develops an integrated equipment that combines a sludge electro-disruption device and an anaerobic dynamic membrane bioreactor, realizing the electro-disruption of the concentrated sludge recycled from the membrane separation zone and then re-recycling it into the digestion system, promoting the dissolution of intracellular organic matter in the sludge, breaking through the rate-limiting steps of cell disruption and hydrolysis acidification in sludge digestion, and effectively avoiding open-lid membrane cleaning, improving the efficiency of sludge anaerobic digestion. When treating sludge by anaerobic digestion, the VS digestion rate of the integrated dynamic membrane bioreactor device with side-stream cell disruption to enhance sludge anaerobic digestion of the present invention reaches more than 45%, and the methane production rate reaches more than 0.5 L / g VS.

[0034] Those of ordinary skill in the art in this technical field should recognize that the above embodiments are only used to illustrate the present invention, rather than to limit the present invention. As long as it is within the scope of the essential spirit of the present invention, changes and modifications to the above embodiments will fall within the scope of the claims of the present invention.

Claims

1. An integrated dynamic membrane bioreactor device for side-flow breaking wall and enhancing anaerobic digestion of sludge, characterized in that, It includes an anaerobic dynamic membrane bioreactor and a sludge electro-rupture device; The anaerobic dynamic membrane bioreactor is of a split type, which includes a main reaction zone and a membrane separation zone; The main reaction zone is connected to the membrane separation zone through a sludge pipeline, and a sludge side-stream inlet is provided on one side of the main reaction zone away from the membrane separation zone; A sludge side-stream outlet is provided at the bottom of the membrane separation zone; A water bath heat preservation coil is provided outside the main reaction zone and the membrane separation zone; The sludge electro-rupture device is connected to the sludge side-stream outlet of the membrane separation zone and the sludge side-stream inlet of the main reaction zone respectively through sludge side-stream pipelines.

2. The integrated dynamic membrane bioreactor device for side-stream cell wall breaking and enhanced anaerobic digestion of sludge according to claim 1, characterized in that, Sludge pumps are provided on the sludge side-stream pipelines on both sides of the sludge electro-rupture device.

3. The integrated dynamic membrane bioreactor device for side-stream cell wall breaking and enhanced anaerobic digestion of sludge according to claim 1, characterized in that, The volume ratio of the membrane separation zone to the main reaction zone is 1:6 to 1:

9.

4. The integrated dynamic membrane bioreactor device for side-stream cell wall breaking and enhanced anaerobic digestion of sludge according to claim 1, wherein A mud inlet is provided on one side of the main reaction zone, a stirrer is provided inside, and a biogas outlet is provided at the top; The membrane separation zone internally integrates a membrane frame, a membrane module and a biogas circulation pipeline. A membrane water outlet and a biogas outlet are provided at the top of the membrane separation zone, and a sludge discharge port is provided at the bottom of the membrane separation zone.

5. Application of an integrated dynamic membrane bioreactor device for side-stream rupture enhanced sludge anaerobic digestion as described in any one of claims 1 to 4 in sludge anaerobic digestion.

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