Vertical pressurization electroosmosis sludge dewatering method and device based on Ti / SnO2-Sb anode

Abstract

The invention discloses a vertical pressurization electroosmosis sludge dewatering method and device based on a Ti / SnO2-Sb anode, and belongs to the technical field of sludge treatment.The vertical pressurization electroosmosis sludge dewatering device comprises a compression device, a supporting device, a main body reactor and a weighing device; from top to bottom, an air compression system is connected with the piston, and a water outlet hole is formed close to the center of the piston and connected to a weighing device through a water conveying hose; a cathode Ti net is arranged at the bottom of the piston and connected with the cathode of the direct-current power supply; a Ti / SnO2-Sb anode is arranged at the bottom of the cylindrical container and is connected with the positive electrode of the direct-current power supply; a round limiting groove is formed in the base, so that subsequent measurement of the water content of the mud cake is facilitated. Sludge is added between the cathode and the anode, and rapid and efficient dehydration can be realized under the dual effects of mechanical pressure and electroosmosis. The vertical pressurization electroosmosis dehydration device is simple in structure and reasonable in design, and compared with a traditional precious metal titanium ruthenium iridium electrode, the Ti / SnO2-Sb anode can reduce the electroosmosis dehydration cost and synchronously achieve sludge reduction.

Description

Technical Field

[0001] The invention relates to a vertical pressurized electro-osmosis sludge dehydration method and device based on Ti / SnO2-Sb anode, belonging to the technical field of sludge dehydration treatment. Technical Background

[0002] With the continuous development of industrialization and people's demand for higher water quality, the scale and number of sewage treatment plants have increased year by year, and the sludge output has also been increasing. As an inevitable product of biological wastewater treatment, sludge contains a variety of pathogens or parasites, toxic pollutants such as heavy metals (Fe, Co, As and other species), and a variety of organic pollutants that can produce odors and greenhouse gases. Over time, these harmful substances will gradually enrich, and if they are not properly disposed of, they may pose a serious threat to the public environment and human health. Sludge dewatering is an important step before disposal. By reducing the volume of sludge, the cost of sludge treatment, disposal and transportation can be reduced. Therefore, it is necessary to pretreat the sludge, which will help to improve the efficiency of mechanical dewatering, as well as the stabilization and harmless treatment of sludge.

[0003] At present, through conventional flocculation conditioning-mechanical dehydration, the sludge moisture content is only reduced to about 80%. In order to further reduce the sludge moisture content for its subsequent treatment and disposal, electroosmosis technology is used to improve the sludge dehydration efficiency. As a green and environmentally friendly emerging dehydration technology, electro-dehydration has the advantages of simple system equipment, small footprint, low operation and maintenance costs, and high reaction controllability. However, the current electro-osmosis technology is still immature in the field of sludge dehydration, especially the various parameters of the market equipment are not easy to adjust, the equipment parts are difficult to replace, the electrode materials are expensive, and there are bottlenecks such as dehydration limits. The present invention provides a vertical pressurized electro-osmosis sludge dehydration method and device based on Ti / SnO2-Sb anode, which has stable and continuous pressure output, and each component is easy to disassemble and convenient for regular cleaning; and compared with the iridium ruthenium precious metal coated titanium anode, the Ti / SnO2-Sb anode used not only reduces the concentration of precious metals in the coating solution, but also can produce more active oxygen than the traditional metal stable anode, further improving the sludge dehydration efficiency. In addition, the bottom-up filtrate discharge method can effectively alleviate the problem of excessive drying of sludge near the anode in the late stage of dehydration, thereby increasing the dehydration limit. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the existing electro-osmosis technology, such as the difficulty in adjusting various parameters, the difficulty in replacing equipment parts, the expensive electrode materials and the dehydration limit, and to provide a method and device for sludge dehydration using vertical pressurized electro-osmosis based on Ti / SnO2-Sb anode, which is simple in structure and easy to operate, so as to solve the above-mentioned problems.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a vertical pressurized electro-osmosis sludge dehydration method and device based on Ti / SnO2-Sb anode, which is mainly composed of a compression device, a support device, a main reactor, and a weighing device; from top to bottom, they are an air compression system, a cylindrical container with an opening at the upper end, and a piston, three water outlet holes are opened near the center of the piston, and are connected to a conical flask through a water hose, a cathode round net is provided at the bottom, and is connected to a DC power supply, a filter cloth is provided under the cathode round net, an anode circular plate is provided at the bottom of the cylindrical container, and is sealed and connected to the inner wall of the container, the anode circular plate is connected to the positive pole of the DC power supply, and a circular limiting groove base is provided at the bottom and is sealed and fitted with a protruding circular ring to prevent sludge from leaking;

[0006] Sludge is added between the cathode cylinder and the anode circular plate, pressure is applied to the cathode, and the DC power supply is turned on when the cathode cylinder contacts the sludge.

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

[0008] Preferably, a filter cloth is provided on the cathode round screen, the filter cloth is made of nylon, and the mesh number of the filter cloth is 240-300.

[0009] Preferably, the power-on time is 20 min to 30 min, and the power-on voltage is 20 to 25 V.

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

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

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

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

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

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

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The invention has a simple structure, reasonable design, and objective operation and maintenance costs. The air compression system used has the characteristic of continuously adjustable pressure. Compared with the pressure provided by heavy objects, the air compression system can adapt to different application requirements, thereby achieving higher flexibility. In addition, the operation of the air compression system is safer. When the pressure exceeds the set value, the air system can automatically cut off the air supply to avoid the danger caused by excessive pressure.

[0018] Compared with the iridium-ruthenium noble metal coated titanium anode, the Ti / SnO2-Sb anode used in the present invention not only reduces the concentration of noble metals in the coating solution, but also improves the catalytic activity of the electrode, generates more free radicals and types, and helps to further improve the sludge dewatering performance.

[0019] The bottom-up filtrate discharge method of the present invention can effectively alleviate the problem of excessive drying of sludge near the anode in the late stage of dehydration, thereby increasing the dehydration limit. In addition, the filtrate is discharged upward through the water outlet hole on the piston, so that a connecting vessel is formed between the columnar container and the conical flask. Therefore, in addition to the electric field force and mechanical pressure, the system will further promote the transfer of water through siphon action. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

[0022] Figure 2 Top view of the piston.

[0023] Description of reference numerals:

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

[0025] The present invention is further described below in conjunction with the accompanying drawings and specific preferred embodiments, but the protection scope of the present invention is not limited thereby.

[0026] Example

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

[0028] Embodiment 1:

[0029] Figure 1 The figure is a schematic diagram of the overall structure of the present invention. A vertical pressurized electro-osmosis sludge dehydration method and device based on Ti / SnO2-Sb anode is mainly composed of a compression device, a support device, a main reactor, and a weighing device; from top to bottom, there are an air compression system 2, a cylindrical container 10 with an opening at the upper end, and a piston 4, three water outlet holes 5 are opened near the center of the piston 4, and are connected to a conical flask 15 through a water hose 14, a cathode round screen 7 is provided at the bottom and is connected to a DC power supply 1, a filter cloth 8 is provided under the cathode round screen 7, an anode circular plate 12 is provided at the bottom of the cylindrical container 10 and is sealed and connected to the inner wall of the container, the anode circular plate 12 is connected to the positive pole of the DC power supply 1, and a circular limiting groove base 13 is provided at the bottom and is sealed and fitted with a protruding ring 11 to prevent sludge from leaking;

[0030] Sludge 9 is added between the cathode round screen 7 and the anode circular plate 12, and pressure is applied to the cathode. When the cathode round screen 7 contacts the sludge 9, the DC power supply 1 is turned on.

[0031] Furthermore, the anode circular plate 12 is based on Ti, and the coating materials used are SnO2 and Sb. Compared with the traditional metal oxide coated titanium anode, the Ti / SnO2-Sb electrode has greater current efficiency and catalytic activity, and exhibits higher electrochemical stability and sustainability; in addition, the free radical content it produces is higher than that of other electrodes, which will help to break down the extracellular polymers and internal cells of the sludge, and further improve the sludge dewatering performance.

[0032] Furthermore, a filter cloth 8 is provided on the cathode round screen 7, and the filter cloth 8 can intercept the sludge and prevent the sludge 9 from entering the weighing device along with the water through the filter cloth 8.

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

[0034] Furthermore, the piston 4 is provided with three water outlet holes 5, and the three water outlet holes 5 are arranged in an equilateral triangle. The uniform distribution of the water outlet holes 5 ensures that the pressure in the inner and outer cavities of the piston 4 is balanced, and can effectively avoid damage to the piston 4 caused by uneven pressure; in addition, the evenly distributed water outlet holes 5 can better conduct heat and reduce 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, the negatively charged sludge migrates to the anode, and the cations and water migrate to the cathode. The anode is arranged at the bottom, which can prevent the dehydration limit problem caused by excessive drying of the sludge near the anode in the late stage of dehydration.

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

[0037] Furthermore, the cylindrical container 10 with an opening at the upper end is located on a circular limiting groove base 13 to prevent the cylindrical container 10 from shifting when pressurized; the cylindrical container 10 can be disassembled separately, which is convenient for cleaning the sludge remaining in the cylindrical container 10 after the experiment and measuring the water content in the sludge 9; the cylindrical container 10 and the circular limiting groove base 13 are made of PC. Compared with plexiglass, PC has better impact resistance and heat resistance, and can effectively deal with the extrusion deformation and high temperature problems generated during the pressurized electro-osmosis process.

[0038] Embodiment 2:

[0039] A vertical pressurized electro-osmosis sludge dewatering method based on Ti / RuO2 anode comprises the following steps:

[0040] (1) The residual sludge was taken from a sewage treatment plant in Changsha. Large impurities were removed through a sieve. After settling for 12 hours, the sludge had a moisture content of 94.5% to 95.5% and a pH of 6.50.

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

[0042] (3) Start the air compression system 2 and set the pressure value to 400 kPa. When the cathode round screen 7 contacts the sludge 9, turn on the DC power supply 1 and set the voltage value to 25 V.

[0043] (4) First, pressurize and electro-osmosis are performed simultaneously for 15 minutes, then pressurize separately for 5 minutes, and finally pressurize and electro-osmosis are performed simultaneously for 10 minutes.

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

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

[0046] Embodiment 3:

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

[0048] (1) The residual sludge was taken from a sewage treatment plant in Changsha. Large impurities were removed through a sieve. After settling for 12 hours, the sludge had a moisture content of 94.5% to 95.5% and a pH of 6.50.

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

[0050] (3) Start the air compression system 2 and set the pressure value to 400 kPa. When the cathode round screen 7 contacts the sludge 9, turn on the DC power supply 1 and set the voltage value to 25 V.

[0051] (4) First, pressurize and electro-osmosis are performed simultaneously for 15 minutes, then pressurize separately for 5 minutes, and finally pressurize and electro-osmosis are performed simultaneously for 10 minutes.

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

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

[0054] The above examples only show one or several embodiments of the present invention, and the descriptions are relatively specific and detailed, but these descriptions cannot be considered to limit the scope of the present invention. It should be emphasized that under the premise of following the concept of the present invention, ordinary technicians in this field can still make some changes and improvements, and these changes and improvements belong to the protection scope of the present invention. Therefore, the scope of the present invention should be based on the contents listed in the claims.

Claims

1. A vertical pressurized electro-osmosis sludge dehydration method and device based on Ti / SnO2-Sb anode, characterized in that: It is mainly composed of a compression device, a supporting device, a main reactor, and a weighing device; from top to bottom, it is an air compression system (2), a cylindrical container (10) with openings at both ends, and a piston (4); three water outlet holes (5) are opened near the center of the piston (4), which are connected to a conical flask (15) through a water hose (14); a cathode round screen (7) is provided at the bottom and is connected to a DC power supply (1); a filter cloth (8) is provided under the cathode round screen (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 pole of the DC power supply (1); a circular limiting groove base (13) is provided at the bottom and is sealed to the protruding ring (11) to prevent the sludge (9) from leaking out; Sludge (9) is added between the cathode round screen (7) and the anode round plate (12), and pressure is applied to the cathode. When the cathode round screen (7) contacts the sludge (9), the DC power supply (1) is turned on.

2. A vertical pressurized electro-osmosis sludge dehydration method and device based on Ti / SnO2-Sb anode according to claim 1, characterized in that: The material of the cathode round screen (7) is Ti, the cathode round screen (7) has prismatic holes, and the material of the anode circular plate (12) is Ti / SnO2-Sb.

3. A method and device for vertical pressurized electro-osmosis sludge dehydration based on Ti / SnO2-Sb anode according to claim 2, characterized in that: A filter cloth (8) is arranged on the cathode round screen (7). The filter cloth (8) is made of nylon and has a mesh size of 240 to 300.

4. A vertical pressurized electro-osmosis sludge dehydration method and device based on Ti / SnO2-Sb anode according to claim 1, characterized in that: The power-on time is 20 minutes to 30 minutes, and the power-on voltage is 20 to 25V.

5. A vertical pressurized electro-osmosis sludge dehydration method and device based on Ti / SnO2-Sb anode according to claim 1, characterized in that: The mechanical pressure of the piston (4) is provided by an air compression system (2), and the mechanical pressure is 400 kPa to 500 kPa.

6. A vertical pressurized electro-osmosis sludge dehydration method and device based on Ti / SnO2-Sb anode according to claim 1, characterized in that: The piston (4) is provided with three water outlet holes (5), and the three water outlet holes (5) are arranged in an equilateral triangle.

7. A vertical pressurized electro-osmosis sludge dehydration method and device based on Ti / SnO2-Sb anode according to claim 1, characterized in that: The filtrate of the sludge (9) is discharged from bottom to top.

8. A method and device for vertical pressurized electro-osmosis sludge dehydration based on Ti / SnO2-Sb anode according to claim 1, characterized in that: The cathode round screen (7) is installed at the bottom of the piston (4), and the anode round plate (12) is installed at the bottom of the cylindrical container (10). Both the cathode round screen (7) and the anode round plate (12) are detachable.

9. A vertical pressurized electro-osmosis sludge dehydration method and device based on Ti / SnO2-Sb anode according to claim 1, characterized in that: The cylindrical container (10) with openings at both ends is located on a circular limiting groove base (13); a protruding ring (11) is provided on the cylindrical container (10) at a distance of 10 mm from the bottom thereof; the protruding ring (11) and the circular limiting groove base (13) are connected via a flange; and the cylindrical container (10), the protruding ring (11) and the circular limiting groove base (13) are all made of PC.

10. According to the vertical pressurized electro-osmosis sludge dehydration method and device based on Ti / SnO2-Sb anode according to claim 9, the inner diameter of the cylindrical container (10) is 70 mm, the cylindrical container (10) is 14 mm away from the support rod (3), and the groove depth of the circular limiting groove base (13) is 10 mm.

Images