A method and apparatus for vertical pressurized electro-osmotic sludge dewatering based on Ti / SnO2-Sb anodes

Abstract

The application discloses a kind of vertical pressurization electroosmosis sludge dewatering method and device based on Ti / SnO2-Sb anode, belong to sludge treatment technical field, including compression device, support device, main reactor, weighing device;From top to bottom, piston is connected by air compression system, water outlet hole is opened near the center of piston, is connected to weighing device by water delivery hose;Piston bottom is equipped with cathode Ti net, and is connected with direct-current power negative electrode;Cylindrical container bottom is equipped with Ti / SnO2-Sb anode and is connected with direct-current power positive electrode;Base is equipped with circular limit recess, facilitate subsequent determination of mud cake moisture content.The sludge is added between cathode and anode, under the dual action of mechanical pressure and electroosmosis, rapid and efficient dewatering can be realized.The vertical pressurization electroosmosis dewatering device of the application is simple in structure and reasonable in design, compared with traditional noble metal titanium ruthenium iridium electrode, the application of Ti / SnO2-Sb anode can reduce the cost of electroosmosis dewatering and realize sludge reduction simultaneously.

Description

Technical Field

[0001] This invention relates to a vertical pressurized electro-osmosis sludge dewatering method and apparatus based on a Ti / SnO2-Sb anode, belonging to the field of sludge dewatering technology. Technical Background

[0002] With continuous industrial development and increasing demands for higher water quality, the scale and number of wastewater treatment plants are increasing year by year, leading to a continuous increase in sludge production. Sludge, an unavoidable byproduct of biological wastewater treatment, contains various pathogens and parasites, toxic pollutants such as heavy metals (Fe, Co, As, etc.), and various organic pollutants that produce odors and greenhouse gases. Over time, these harmful substances accumulate, and if not properly disposed of, may pose a serious threat to the public environment and human health. Sludge dewatering is a crucial step before disposal, reducing sludge volume to lower the costs of sludge treatment, disposal, and transportation. Therefore, sludge pretreatment is necessary, which will help improve the efficiency of subsequent mechanical dewatering and the stabilization and harmless treatment of the sludge.

[0003] Currently, conventional flocculation conditioning followed by mechanical dewatering only reduces sludge moisture content to around 80%. To further reduce sludge moisture content for subsequent treatment, electro-osmosis technology is being used to improve sludge dewatering efficiency. Electro-osmosis, as a green and environmentally friendly emerging dewatering technology, has advantages such as simple system equipment, small footprint, low operating and maintenance costs, and high controllability of the reaction. However, current electro-osmosis technology is still immature in the field of sludge dewatering, especially due to bottlenecks such as difficulty in adjusting various parameters, difficulty in replacing equipment parts, expensive electrode materials, and dewatering limits in commercially available equipment. This invention presents a vertical pressurized electro-osmosis sludge dewatering method and apparatus based on a Ti / SnO2-Sb anode, which has stable and continuous pressure output, and the components are easy to disassemble for regular cleaning. Furthermore, compared to iridium-ruthenium precious metal coated titanium anodes, the Ti / SnO2-Sb anode not only reduces the concentration of precious metals in the coating solution but also generates more active oxygen than traditional metal stable anodes, further improving sludge dewatering efficiency. In addition, the bottom-up filtrate discharge method can effectively alleviate the problem of excessive drying of sludge near the anode in the later stage of dewatering, thereby increasing the dewatering limit. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing electroosmosis technology, such as the difficulty in adjusting various parameters, the difficulty in replacing equipment parts, the high cost of electrode materials, and the dewatering limit. It provides a method and apparatus for sludge dewatering that is simple in structure, easy to operate, and utilizes vertical pressurized electroosmosis based on Ti / SnO2-Sb anodes, thereby solving the aforementioned problems.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a vertical pressurized electro-osmotic sludge dewatering method and apparatus based on Ti / SnO2-Sb anode, mainly composed of a compression device, a support device, a main reactor, and a weighing device; from top to bottom, there is an air compression system, a cylindrical container with an open top and a piston, with three small water outlet holes near the center of the piston, connected to a conical flask through a water supply hose, a cathode circular mesh at the bottom connected to a DC power supply, a filter cloth below the cathode circular mesh, an anode circular plate at the bottom of the cylindrical container that is sealed to the inner wall of the container, the anode circular plate being connected to the positive terminal of the DC power supply, and a circular limiting groove base at the bottom that is sealed to the protruding circular ring to prevent sludge leakage;

[0006] Sludge is added between the cathode circular mesh and the anode circular plate, pressure is applied to the cathode, and the DC power supply is turned on when the cathode circular mesh comes into contact with the sludge.

[0007] Preferably, the cathode circular mesh is made of Ti, the cathode circular mesh has prismatic holes, and the anode circular plate is made of Ti / SnO2-Sb.

[0008] Preferably, a filter cloth is provided on the cathode circular mesh, the filter cloth material is nylon, and the mesh count of the filter cloth is 240. 300.

[0009] Preferably, the power-on time is 20 minutes. 30 minutes, energized voltage is 20 25V.

[0010] Preferably, the mechanical pressure of the piston is provided by an air compression system, and the mechanical pressure is 400 kPa. 500 kPa.

[0011] Preferably, the piston is provided with three water outlet holes, which are arranged in an equilateral triangle.

[0012] Preferably, the sludge filtrate is discharged from bottom to top.

[0013] Preferably, the cathode circular mesh is installed at the bottom of the piston, and the anode circular plate is installed at the bottom of the cylindrical container; both the cathode circular mesh and the anode circular plate are detachable.

[0014] Preferably, the cylindrical container with openings at both ends is located on a circular limiting groove base, and a protruding ring is provided 10mm from the bottom of the cylindrical container. The protruding ring and the circular limiting groove base are connected by a flange, and the cylindrical container, the protruding ring and the circular limiting groove base are all made of PC.

[0015] Preferably, the inner diameter of the cylindrical container is 70mm, the distance between the cylindrical container and the support rod is 14mm, and the groove depth of the circular limiting groove base is 10mm.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0017] This invention features a simple structure, reasonable design, and reasonable operation and maintenance costs. The employed air compression system boasts continuously adjustable pressure, allowing it to adapt to diverse application needs and offering greater flexibility compared to pressure provided by heavy objects. Furthermore, the air compression system is safer to operate. When the pressure exceeds the set value, the air system automatically cuts off the air supply, preventing dangers caused by excessive pressure.

[0018] Compared to titanium anodes with iridium-ruthenium noble metal coatings, the Ti / SnO2-Sb anode used in this invention not only reduces the concentration of noble metals in the coating solution but also improves the catalytic activity of the electrode, generating more free radicals of greater content and variety, which helps to further improve the sludge dewatering performance.

[0019] The bottom-up filtrate discharge method of this invention can effectively alleviate the problem of excessive drying of sludge near the anode in the later stage of dehydration, thereby increasing the dehydration limit. In addition, the upward discharge of filtrate through the outlet hole on the piston creates a communicating vessel between the cylindrical container and the conical flask. Therefore, in addition to electric field force and mechanical pressure, the system will further promote the transfer of water through siphon effect. Attached Figure Description

[0020] To facilitate a better understanding by those skilled in the art, the present invention will now be described in detail with reference to the accompanying drawings.

[0021] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0022] Figure 2 This is a top view of the piston.

[0023] Explanation of reference numerals in the attached figures:

[0024] 1. DC power supply; 2. Air compression system; 3. Support rod; 4. Piston; 5. Water outlet; 6. Wire hole; 7. Cathode circular mesh; 8. Filter cloth; 9. Sludge; 10. Cylindrical container; 11. Protruding ring; 12. Anode circular plate; 13. Circular limiting groove base; 14. Water delivery hose; 15. Conical flask; 16. Electronic balance. Detailed Implementation

[0025] The present invention will be further described below with reference to the accompanying drawings and specific preferred embodiments, but this does not limit the scope of protection of the present invention.

[0026] Example

[0027] The materials and instruments used in the following examples are all commercially available. (The electroosmosis device was custom-made by a chemical instrument manufacturer.)

[0028] Example 1:

[0029] Figure 1 This is a schematic diagram of the overall structure of the present invention. A method and apparatus for vertical pressurized electro-osmotic sludge dewatering based on Ti / SnO2-Sb anode mainly consists of a compression device, a support device, a main reactor, and a weighing device. From top to bottom, the apparatus consists of an air compression system 2, a cylindrical container 10 with an open top, and a piston 4. Three small water outlet holes 5 are opened near the center of the piston 4 and connected to a conical flask 15 through a water supply hose 14. A cathode circular mesh 7 is provided at the bottom and connected to a DC power supply 1. A filter cloth 8 is provided below the cathode circular mesh 7. An anode circular plate 12 is provided at the bottom of the cylindrical container 10 and is sealed to the inner wall of the container. The anode circular plate 12 is connected to the positive terminal of the DC power supply 1. A circular limiting groove base 13 is provided at the bottom and is sealed to the protruding circular ring 11 to prevent sludge leakage.

[0030] Sludge 9 is added between the cathode circular mesh 7 and the anode circular plate 12, and pressure is applied to the cathode. When the cathode circular mesh 7 comes into contact with the sludge 9, the DC power supply 1 is turned on.

[0031] Furthermore, the anode disc 12 is based on Ti, and the coating materials used are SnO2 and Sb. Compared with traditional metal oxide coated titanium anodes, the Ti / SnO2-Sb electrode has greater current efficiency and catalytic activity, and exhibits higher electrochemical stability and sustainability. In addition, it generates more free radicals than other electrodes, which will help to break down extracellular polymers and internal cells in sludge, further improving sludge dewatering performance.

[0032] Furthermore, the cathode circular mesh 7 is provided with a filter cloth 8, which can trap sludge and prevent sludge 9 from entering the weighing device along with water through the filter cloth 8.

[0033] Furthermore, the compression force of the piston 4 is provided by the air compression system 2. The air compression system 2 is designed to be stable and can operate continuously. They are generally able to adapt to different working conditions and requirements and can be adjusted according to specified pressure and speed to improve the reliability of the system.

[0034] Furthermore, the piston 4 is provided with three water outlet holes 5, which are arranged in an equilateral triangle. The uniform distribution of the water outlet holes 5 ensures the pressure balance between the inner and outer cavities of the piston 4, which can effectively prevent damage to the piston 4 caused by uneven pressure. In addition, the uniformly distributed water outlet holes 5 can better dissipate heat, reduce the deformation or cracks of the piston 4 caused by thermal stress, thereby improving the durability and service life of the piston 4 and the safety of the entire system operation.

[0035] Furthermore, the sludge filtrate is discharged from bottom to top, with negatively charged sludge migrating towards the anode and cations and water migrating towards the cathode. The anode is positioned at the bottom to prevent the dewatering limit problem caused by excessive drying of the sludge near the anode in the later stages of dewatering.

[0036] Furthermore, the cathode circular mesh 7 is installed at the bottom of the piston 4, and the anode circular plate 12 is installed at the bottom of the cylindrical container 10. Both the cathode circular mesh 7 and the anode circular plate 12 are detachable, which facilitates regular cleaning and replacement.

[0037] Furthermore, the cylindrical container 10 with an open upper end is located on the circular limiting groove base 13 to prevent the cylindrical container 10 from shifting during pressurization; the cylindrical container 10 can be disassembled separately to facilitate cleaning the sludge remaining in the cylindrical container 10 after the experiment and to measure the moisture content of the sludge 9; the cylindrical container 10 and the circular limiting groove base 13 are made of PC, which has better impact resistance and heat resistance than plexiglass, and can effectively cope with the extrusion deformation and high temperature problems generated during pressurized electroosmosis.

[0038] Example 2:

[0039] A vertical pressurized electro-osmotic sludge dewatering method based on Ti / RuO2 anodes includes the following steps:

[0040] (1) The residual sludge taken from a sewage treatment plant in Changsha City was screened to remove larger impurities. After settling for 12 hours, the sludge moisture content was 94.5% to 95.5% and the sludge pH was 6.50.

[0041] (2) Pour 80g of well-stirred sludge 9 into the electro-osmosis device.

[0042] (3) Start the air compression system 2, set the pressure value to 400 kPa, and when the cathode circular mesh 7 comes into contact with the sludge 9, turn on the DC power supply 1 and set the voltage value to 25 V.

[0043] (4) First, pressurize and electroosmosis simultaneously for 15 minutes, then pressurize alone for 5 minutes, and finally pressurize and electroosmosis simultaneously for 10 minutes.

[0044] (5) Turn off the air compression system 2 and DC power supply 1, turn on the pressurized electroosmosis device, and take out the pressed sludge 9 from the circular limit groove base 13.

[0045] (6) The sludge 9 was placed in an oven and dried for 24 hours. The moisture content of the sludge cake was calculated to be 73.73% by weight.

[0046] Example 3:

[0047] The sludge dewatering equipment structure and steps are the same as in Example 2. A vertical pressurized electro-osmosis sludge dewatering method based on Ti / SnO2-Sb anode includes the following steps:

[0048] (1) The residual sludge taken from a sewage treatment plant in Changsha City was screened to remove larger impurities. After settling for 12 hours, the sludge moisture content was 94.5% to 95.5% and the sludge pH was 6.50.

[0049] (2) Pour 80g of well-stirred sludge 9 into the electro-osmosis device.

[0050] (3) Start the air compression system 2, set the pressure value to 400 kPa, and when the cathode circular mesh 7 comes into contact with the sludge 9, turn on the DC power supply 1 and set the voltage value to 25 V.

[0051] (4) First, pressurize and electroosmosis simultaneously for 15 minutes, then pressurize alone for 5 minutes, and finally pressurize and electroosmosis simultaneously for 10 minutes.

[0052] (5) Turn off the air compression system 2 and DC power supply 1, turn on the pressurized electroosmosis device, and take out the pressed sludge 9 from the circular limit groove base 13.

[0053] (6) The sludge 9 was placed in an oven and dried for 24 hours. The moisture content of the sludge cake was calculated to be 61.88% by weight.

[0054] The examples above only illustrate one or more embodiments of the present invention, and the descriptions are relatively specific and detailed, but these descriptions should not be construed as limiting the scope of the present invention. It should be emphasized that, while adhering to the inventive concept, those skilled in the art can still make some changes and modifications, and these changes and modifications all fall within the protection scope of the present invention. Therefore, the scope of the present invention should be determined by the contents listed in the claims.

Claims

1. A vertical pressurized electro-osmotic sludge dewatering device based on a Ti / SnO2-Sb anode, characterized in that: The device includes an air compression system (2), a cylindrical container (10) with openings at both ends, and a DC power supply (1). A piston (4) is installed inside the cylindrical container (10), and the mechanical pressure of the piston (4) is provided by the air compression system (2). The piston (4) has three water outlets (5), which are connected to a conical flask (15) via a water delivery hose (14). The cylindrical container (10) also contains a cathode circular mesh (7) and a filter cloth (8). The cathode circular mesh (7) is located below the piston (4) and is connected to the negative terminal of the DC power supply (1). The filter cloth (8) is located below the cathode. Below the circular mesh (7); the bottom of the cylindrical container (10) is provided with an anode circular plate (12), the anode circular plate (12) is sealed to the inner wall of the cylindrical container (10), the anode circular plate (12) is connected to the positive terminal of the DC power supply (1), and the material of the anode circular plate (12) is Ti / SnO2-Sb; a circular limiting groove base (13) is provided below the cylindrical container (10), and a protruding ring (11) is provided at the bottom of the cylindrical container (10). The protruding ring (11) and the circular limiting groove base (13) are sealed and fitted to prevent the sludge (9) in the cylindrical container (10) from leaking out.

2. The vertical pressurized electro-osmotic sludge dewatering device based on a Ti / SnO2-Sb anode according to claim 1, characterized in that, The cathode circular mesh (7) is made of Ti and has rhomboid holes.

3. The vertical pressurized electro-osmotic sludge dewatering device based on a Ti / SnO2-Sb anode according to claim 2, characterized in that, The filter cloth (8) is made of nylon and has a mesh count of 240 to 300.

4. The vertical pressurized electro-osmotic sludge dewatering device based on a Ti / SnO2-Sb anode according to claim 1, characterized in that, The three water outlets (5) are arranged in an equilateral triangle.

5. The vertical pressurized electro-osmotic sludge dewatering device based on a Ti / SnO2-Sb anode according to claim 1, characterized in that, Both the cathode circular mesh (7) and the anode circular plate (12) are detachable.

6. The vertical pressurized electro-osmotic sludge dewatering device based on a Ti / SnO2-Sb anode according to claim 1, characterized in that, The cylindrical container (10), the protruding ring (11), and the circular limiting groove base (13) are all made of PC.

7. A method for vertical pressurized electro-osmosis sludge dewatering based on a Ti / SnO2-Sb anode, employing the vertical pressurized electro-osmosis sludge dewatering device based on a Ti / SnO2-Sb anode as described in any one of claims 1-6, characterized in that, Includes the following steps: Sludge (9) is added between the cathode circular mesh (7) and the anode circular plate (12). Pressure is applied to the cathode circular mesh (7). When the cathode circular mesh (7) comes into contact with the sludge (9), the DC power supply (1) is turned on. The power supply time is 20 min to 30 min and the power supply voltage is 20 to 25 V.

8. The vertical pressurized electro-osmotic sludge dewatering method based on a Ti / SnO2-Sb anode according to claim 7, characterized in that, The mechanical pressure provided by the air compression system (2) is 400 kPa to 500 kPa.

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