Multi-section type dynamic membrane sludge concentration integrated equipment and application

Abstract

The invention discloses multi-stage dynamic membrane sludge concentration integrated equipment and application, the multi-stage dynamic membrane sludge concentration integrated equipment comprises multiple stages of dynamic membrane sludge concentration tanks which are arranged in series, and each dynamic membrane sludge concentration tank is internally provided with a dynamic membrane assembly; the first-stage dynamic membrane sludge concentration tank is provided with a sludge inlet, the last-stage dynamic membrane sludge concentration tank is provided with a sludge outlet, the adjacent dynamic membrane sludge concentration tanks are connected through overflow ports, and the overflow port on the previous dynamic membrane sludge concentration tank is higher than the overflow port on the next dynamic membrane sludge concentration tank; a membrane water outlet is formed in the top of each dynamic membrane component; a biogas circulating pipeline connected with biogas is arranged at the bottom of each dynamic membrane component. The sludge concentration effect can be further enhanced, the treatment volume is reduced, and the subsequent treatment of the sludge is economical.

Description

Technical Field

[0001] The invention belongs to the technical field of sludge concentration, and relates to multi-stage dynamic membrane sludge concentration integrated equipment and application. Background Art

[0002] Sludge thickening is one of the important steps in the sludge treatment and disposal process. Its purpose is to reduce the moisture content and volume of the sludge to reduce the treatment and disposal pressure. When dynamic membrane bioreactor technology is applied to sludge thickening, effective sludge thickening can be achieved by decoupling the hydraulic retention time and solid retention time.

[0003] Currently, sewage treatment plants commonly use gravity thickening tanks for sludge thickening. Gravity thickening utilizes the gravity of solid particles in sludge to cause natural sedimentation and compaction. Residual sludge with a moisture content of 99.7% to 99.2% can be reduced to 98% to 97% through gravity thickening. Conventional gravity thickening has numerous drawbacks, including the large floor space required by gravity thickening tanks and high civil engineering investment. Furthermore, sludge has poor settling properties under conventional gravity thickening, resulting in poor sludge thickening results, a low solids content after thickening, and increased chemical and energy consumption for subsequent conditioning and dehydration. Summary of the Invention

[0004] In response to the problem in the prior art that the residual sludge has poor sedimentation performance under conventional gravity concentration, resulting in poor sludge concentration effect, the purpose of the present invention is to provide a multi-stage dynamic membrane sludge concentration integrated equipment and application, which realizes the solid-liquid separation of the sludge, enhances the sludge concentration effect through a series arrangement, and improves the sludge discharge concentration of the system, with the advantages of small footprint, easy operation and advancedness.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A first aspect of the present invention provides a multi-stage dynamic membrane sludge concentration integrated equipment, comprising a plurality of dynamic membrane sludge concentration tanks arranged in series, each of which is provided with a dynamic membrane assembly;

[0007] The first stage dynamic membrane sludge thickening tank is provided with a mud inlet, the last stage dynamic membrane sludge thickening tank is provided with a mud outlet, and adjacent dynamic membrane sludge thickening tanks are connected by overflow ports, and the overflow port on the previous dynamic membrane sludge thickening tank is higher than the overflow port on the next dynamic membrane sludge thickening tank;

[0008] The top of each dynamic membrane component is provided with a membrane water outlet; the bottom of each dynamic membrane component is provided with a biogas circulation pipeline connected with biogas.

[0009] Preferably, the dynamic membrane sludge thickening tank is provided with at least three stages.

[0010] Preferably, the overflow port on the last stage dynamic membrane sludge thickening tank is higher than the sludge discharge port on the last stage dynamic membrane sludge thickening tank.

[0011] Preferably, the dynamic membrane assembly comprises a plurality of flat membranes arranged at equal intervals, and each flat membrane is provided with a flat membrane outlet connected to the membrane outlet.

[0012] Preferably, the flat membrane uses a micromesh substrate with a membrane pore size of 30-100 μm, and the micromesh substrate is selected from non-woven fabrics or nylon mesh.

[0013] Preferably, the biogas circulation pipeline includes a biogas main pipe connected to the biogas and a plurality of biogas branch pipes connected to the biogas main pipe and arranged in parallel at the bottom of the dynamic membrane module; The biogas branch pipe is vertically arranged with the plurality of flat membranes on the dynamic membrane assembly; the biogas branch pipe is provided with a plurality of aeration holes distributed at equal intervals, and the plurality of aeration holes and the plurality of flat membranes are alternately arranged.

[0014] The second aspect of the present invention provides an application of the multi-stage dynamic membrane sludge concentration integrated equipment as described in the first aspect of the present invention in sludge concentration.

[0015] The present invention has the following beneficial effects: 1. The present invention introduces dynamic membrane bioreactor technology based on the sludge treatment process, utilizes the sludge layer deposited on the surface of the macroporous substrate in the initial filtration stage to achieve the function of solid-liquid separation, and realizes the step-by-step concentration of sludge through multi-stage dynamic membrane sludge thickening tanks arranged in series. The residual sludge with a moisture content of 99.7% to 99.2% can be gradually concentrated to 95% to 96%, and membrane fouling is controlled according to the subcritical flux operation mode. According to the subcritical flux operation mode, a low operating flux is adopted at high sludge concentration, and a high operating flux is adopted at low sludge concentration, thereby avoiding the problem of a decrease in operating flux caused by an increase in sludge concentration. In addition, it can effectively solve the problem of poor sludge concentration effect caused by poor settling performance of residual sludge under conventional gravity concentration, and has a smaller footprint and is easier to achieve automated control. 2. The present invention adopts dynamic membrane bioreactor technology, relying on the dynamic membrane formed on the support layer to decouple and separate the HRT and SRT, thus achieving solid-liquid separation of sludge. It has the advantages of small footprint, easy operation, advanced technology, economy and low carbon. The arrangement of multi-stage dynamic membrane sludge thickening tanks in series further enhances the sludge concentration effect, increases the sludge discharge concentration of the system, and provides a technical foundation for the treatment and disposal of high-concentration sludge. 3. The present invention takes the dynamic membrane bioreactor technology as the main body, and uses the sludge layer deposited on the surface of the macroporous substrate at the initial stage of filtration to realize the function of solid-liquid separation, greatly reducing the initial investment. At the same time, the macroporous substrate requires a small filtration pressure, low energy consumption, and simple membrane cleaning steps. By decoupling the HRT (hydraulic retention time) and SRT (solid retention time), the floor area of the equipment and the civil engineering cost are reduced. The multi-stage dynamic membrane excess sludge concentration process strengthens the sludge concentration effect and reduces the pressure of subsequent treatment and disposal. 4. The present invention uses the dynamic membrane technology for sludge solid-liquid separation, and at the same time arranges a multi-stage dynamic membrane sludge concentration tank, which further improves the sludge concentration effect, and has the characteristics of advanced nature, easy operation, and small floor area, effectively improving the operation efficiency and stability of the system. In addition, the system design is applicable to various treatment scenarios with a sludge concentration of 30 - 60 g / L, has broad application potential, provides a reliable solution for the efficient treatment and resource utilization of sludge, and can be promoted. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Other features, objects, 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:

[0017] Figure 1 It is a schematic structural diagram of the multi-stage dynamic membrane sludge concentration integrated equipment of the present invention;

[0018] Wherein, 1. The first-stage dynamic membrane sludge concentration tank; 11. The sludge inlet; 12. The overflow port; 2. The second-stage dynamic membrane sludge concentration tank; 21. The overflow port; 3. The third-stage dynamic membrane sludge concentration tank; 31. The sludge discharge port; 4. The membrane water outlet; 5. The dynamic membrane module; 51. The flat membrane; 52. The flat membrane water outlet; 6. The biogas circulation pipeline; 61. The biogas branch pipe; 62. The gas diffusion hole. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] 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.

[0020] Combined with Figure 1 As shown, the present invention provides a multi-stage dynamic membrane sludge concentration integrated equipment, including a multi-stage dynamic membrane sludge concentration tank arranged in series, and a dynamic membrane module 5 is provided in each dynamic membrane sludge concentration tank. A sludge inlet 11 is provided on the first-stage dynamic membrane sludge concentration tank, a sludge discharge port is provided on the last-stage dynamic membrane sludge concentration tank, and adjacent dynamic membrane sludge concentration tanks are connected through an overflow port. The overflow port on the previous dynamic membrane sludge concentration tank is higher than the overflow port on the subsequent dynamic membrane sludge concentration tank. A membrane water outlet 4 is provided at the top of each dynamic membrane module 5; a biogas circulation pipeline 6 connected to biogas is provided at the bottom of each dynamic membrane module.

[0021] The present invention introduces the dynamic membrane bioreactor technology on the basis of the sludge treatment process, uses the sludge layer deposited on the surface of the membrane module at the initial stage of filtration to achieve solid-liquid separation, and realizes the step-by-step concentration of sludge through a multi-stage dynamic membrane sludge thickening tank arranged in series. The excess sludge with a water content of 99.7% - 99.2% can be gradually concentrated to 95% - 96%. In addition, membrane fouling can be controlled according to the sub-critical flux operation mode.

[0022] Combined with Figure 1 As shown, in a specific scheme, at least three stages of dynamic membrane sludge thickening tanks are provided.

[0023] Combined with Figure 1 As shown, in the multi-stage dynamic membrane sludge thickening tank, the overflow port on the last-stage dynamic membrane sludge thickening tank is higher than the sludge discharge port on the last-stage dynamic membrane sludge thickening tank; therefore, the height of the sludge liquid level in the multi-stage dynamic membrane sludge thickening tank decreases in series order, which is convenient for the sludge to automatically enter the subsequent dynamic membrane sludge thickening tank through the overflow port under the action of gravity for continuous concentration. For example, the sludge liquid level of the first-stage dynamic membrane sludge thickening tank 1 is higher than that of the second-stage dynamic membrane sludge thickening tank 2, and the sludge liquid level of the second-stage dynamic membrane sludge thickening tank 2 is higher than that of the third-stage dynamic membrane sludge thickening tank 3.

[0024] Combined with Figure 1 As shown, the dynamic membrane module 5 includes a plurality of flat membranes �1 arranged at equal intervals, and each flat membrane �1 is provided with a flat membrane water outlet �2 connected to the membrane water outlet 4. The flat membrane �1 uses a micro-mesh substrate with a membrane pore size of 30 - 100 μm, and the micro-mesh substrate is selected from non-woven fabric or nylon mesh.

[0025] Combined with Figure 1 As shown, the biogas circulation pipeline 6 includes a biogas main pipe connected to biogas and a plurality of biogas branch pipes 61 arranged in parallel at the bottom of the dynamic membrane module 5 and connected to the biogas main pipe; the biogas branch pipes 61 are vertically arranged with a plurality of flat membranes � in the dynamic membrane module 5; a plurality of equally spaced aeration holes 62 are provided on the biogas branch pipes 61, and the plurality of aeration holes are alternately arranged with the plurality of flat membranes.

[0026] The above multi-stage dynamic membrane sludge thickening integrated equipment is applicable to a sludge thickening system with an influent sludge concentration of 3 - 8 g / L; taking the three-stage dynamic membrane sludge thickening tank arranged in series as an example, when it is applied to sludge thickening, at normal temperature, according to the sub-critical flux operation mode, the membrane flux of the first-stage dynamic membrane sludge thickening tank is 25 - 35 L / (m 2 ·h), the membrane flux of the second-stage dynamic membrane sludge thickening tank is 15 - 25 L / (m 2 ·h), and the membrane flux of the third-stage dynamic membrane sludge thickening tank is 5 - 15 L / (m 2· h), it can effectively decouple the hydraulic retention time and the solid retention time of the system, and the sludge discharge concentration is 50 - 60 g / L. In addition, due to the small filtration resistance of the dynamic membrane, it can operate in a constant pressure or constant flow mode. In the constant pressure mode, there is no need to equip a dedicated outlet water pump, and the filtration is driven by the head loss between the reactor water level and the outlet water level. In the constant flow mode, the filtration flux remains constant under the action of a peristaltic / suction pump. Under long-term operating conditions, the dynamic membrane is easy to clean and regenerate, and only simple physical cleaning is required to restore the filtration performance of the dynamic membrane.

[0027] Example 1

[0028] In this example, the multi-stage dynamic membrane sludge thickening integrated equipment of the present invention is adopted, which includes a first-stage dynamic membrane sludge thickening tank 1, a second-stage dynamic membrane sludge thickening tank 2, and a third-stage dynamic membrane sludge thickening tank 3 arranged in series. Each dynamic membrane sludge thickening tank is provided with a dynamic membrane module 5. The first-stage dynamic membrane sludge thickening tank 1 is provided with a sludge inlet 11, and a sludge discharge port 31 is provided at a position near the bottom of the third-stage dynamic membrane sludge thickening tank 3; adjacent dynamic membrane sludge thickening tanks are connected through an overflow port, and the overflow port on the previous dynamic membrane sludge thickening tank is higher than the overflow port on the subsequent dynamic membrane sludge thickening tank, that is, the overflow port 12 of the first-stage dynamic membrane sludge thickening tank 1 is higher than the overflow port 21 of the second-stage dynamic membrane sludge thickening tank 2, and the overflow port 21 of the second-stage dynamic membrane sludge thickening tank 2 is higher than the sludge discharge port 31 of the third-stage dynamic membrane sludge thickening tank 3. A membrane water outlet 4 is provided at the top of each dynamic membrane module 5, and a biogas circulation pipeline 6 connected to biogas is provided at the bottom; the dynamic membrane module includes a plurality of flat membranes 51 arranged at equal intervals, and each flat membrane 51 is provided with a flat membrane water outlet 52 connected to the membrane water outlet 4. The biogas circulation pipeline 6 includes a biogas main pipe and a plurality of parallel biogas branch pipes 61; the biogas branch pipes 61 are perpendicular to the plurality of flat membranes 51 on the dynamic membrane module 5; a plurality of equally spaced gas holes 62 are provided on the biogas branch pipes 61, and the plurality of gas holes 62 and the plurality of flat membranes 51 are arranged alternately.

[0029] The multi-stage dynamic membrane sludge thickening integrated equipment uses a dynamic membrane module with a polyester mesh with a pore size of 38 μm as the base material. When applied to sludge thickening, for a sludge thickening system with an influent concentration of 3 - 8 g / L, the equipment operates in a constant flow mode, and the membrane fluxes of the first-stage dynamic membrane sludge thickening tank 1, the second-stage dynamic membrane sludge thickening tank 2, and the third-stage dynamic membrane sludge thickening tank 3 are set to 30 L / (m 2 · h), 20 L / (m 2 · h), 10 L / (m 2· h), it reached stability after running for 10 days. The sludge concentrations in the three dynamic membrane sludge thickening tanks were maintained at 16.9 ± 2.6 g / L, 33.4 ± 1.7 g / L, and 54.2 ± 2.1 g / L respectively, and the membrane pressures in the thickening tanks were maintained below 5 kPa, below 10 kPa, and below 35 kPa respectively.

[0030] Example 2

[0031] In this example, most of it is the same as Example 1. The difference is that the membrane fluxes of the first - stage dynamic membrane sludge thickening tank 1, the second - stage dynamic membrane sludge thickening tank 2, and the third - stage dynamic membrane sludge thickening tank 3 are set to 35 L / (m 2 · h), 25 L / (m 2 · h), 15 L / (m 2 · h) respectively. It reached stability after running for 8 days. The sludge concentrations in the three dynamic membrane sludge thickening tanks were maintained at 19.2 ± 1.4 g / L, 35.3 ± 2.9 g / L, and 58.5 ± 2.4 g / L respectively, and the membrane pressures in the thickening tanks were maintained below 8 kPa, below 13 kPa, and below 35 kPa respectively.

[0032] In summary, the present invention uses the dynamic membrane bioreactor technology for decoupling and separation regulation of HRT and SRT, and arranges multiple - stage dynamic membrane sludge thickening tanks in series, thereby realizing step - by - step sludge thickening, strengthening the sludge thickening effect, and can gradually thicken the excess sludge with a moisture content of 99.7% - 99.2% to 95% - 96%, and controlling membrane fouling according to the sub - critical flux operation mode.

[0033] 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 - described embodiments will fall within the scope of the claims of the present invention.

Claims

1. A multi-stage dynamic membrane sludge concentration integrated equipment, characterized in that It includes a multi-stage dynamic membrane sludge thickening tank arranged in series, and a dynamic membrane module is provided in each dynamic membrane sludge thickening tank; A sludge inlet is provided on the first-stage dynamic membrane sludge thickening tank, a sludge discharge port is provided on the last-stage dynamic membrane sludge thickening tank, and adjacent dynamic membrane sludge thickening tanks are connected through an overflow port. The overflow port on the previous dynamic membrane sludge thickening tank is higher than the overflow port on the subsequent dynamic membrane sludge thickening tank; A membrane water outlet is provided at the top of each dynamic membrane module; a biogas circulation pipeline connected to biogas is provided at the bottom of each dynamic membrane module.

2. The multi-stage dynamic membrane sludge concentration integrated equipment according to claim 1, characterized in that, The dynamic membrane sludge thickening tank is provided with at least 3 stages.

3. The multi-stage dynamic membrane sludge concentration integrated equipment according to claim 1, characterized in that, The overflow port on the last-stage dynamic membrane sludge thickening tank is higher than the sludge discharge port on the last-stage dynamic membrane sludge thickening tank.

4. The multi-stage dynamic membrane sludge concentration integrated equipment according to claim 1, characterized in that, The dynamic membrane module includes a plurality of flat membranes arranged at equal intervals, and a flat membrane water outlet connected to the membrane water outlet is provided on each flat membrane.

5. The multi-stage dynamic membrane sludge concentration integrated equipment according to claim 4, characterized in that, The flat membrane adopts a micro-mesh substrate with a membrane pore size of 30 - 100 μm, and the micro-mesh substrate is selected from non-woven fabric or nylon mesh.

6. The multi-stage dynamic membrane sludge concentration integrated equipment according to claim 1, characterized in that The biogas circulation pipeline includes a biogas main pipe connected to biogas and a plurality of biogas branch pipes arranged in parallel at the bottom of the dynamic membrane module and connected to the biogas main pipe; The biogas branch pipes are perpendicular to the plurality of flat membranes on the dynamic membrane module; a plurality of equally spaced aeration holes are provided on the biogas branch pipes, and the plurality of aeration holes and the plurality of flat membranes are arranged alternately.

7. Application of the multi-stage dynamic membrane sludge thickening integrated equipment as described in any one of claims 1 - 6 in sludge thickening.

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