A vacuum electrochemical in-situ dehydration and decontamination system and method for heavy metal dredged contaminated sludge

Abstract

The present invention belongs to the technical field of sludge solidification and remediation of geotechnical engineering and environmental engineering, and in particular, relates to a system and method for vacuum electrochemical in-situ dehydration and decontamination of heavy metal dredged contaminated sludge, including a dredger for collecting contaminated sludge in a river channel and transferring the contaminated sludge to a sludge storage tank; an electroosmosis component, which is arranged in the sludge storage tank, and is used to dehydrate and decontaminate the contaminated sludge transferred to the sludge storage tank; a vacuum component, which is arranged in the sludge storage tank, and is used to provide a vacuum environment when the electroosmosis component dehydrates and decontaminates the contaminated sludge. The present invention utilizes vacuum negative pressure, electromigration and electroosmosis to achieve centralized and rapid treatment of consolidation and drainage of sludge and removal of pollutants; the sludge after in-situ dehydration and decontamination can be utilized as a resource, saving the cost of sludge storage site and reducing the risk of secondary pollution; the vacuum electrochemical in-situ dehydration and decontamination system for dredged sludge can be reused, improving the sustainability and economy of the equipment.

Description

Technical Field

[0001] The invention belongs to the technical field of sludge solidification and restoration in geotechnical engineering and environmental engineering, and in particular relates to a vacuum electrochemical in-situ dehydration and decontamination system and method for heavy metal dredged polluted sludge. Background Art

[0002] Bottom mud is usually produced during dredging of rivers, lakes and ports. It contains a large amount of heavy metal pollutants, which not only threatens the quality of water bodies, but also may be transmitted to humans through the food chain, causing potential harm to public health. Heavy metal dredged polluted mud contains a large amount of water, which not only increases the volume and weight of the mud, but also increases the difficulty of heavy metal pollutant treatment.

[0003] Therefore, it is necessary to design a vacuum electrochemical in-situ dehydration and decontamination system and method for heavy metal dredging contaminated sludge to solve the above problems. Summary of the invention

[0004] The purpose of the present invention is to provide a heavy metal dredged contaminated sludge vacuum electrochemical in-situ dehydration and decontamination system and method to solve the above problems and achieve the purpose of improving the treatment effect of heavy metal pollutants.

[0005] To achieve the above object, the present invention provides the following scheme: a vacuum electrochemical in-situ dehydration and decontamination system for heavy metal dredged contaminated sludge, comprising:

[0006] Dredgers are used to collect polluted sludge from the river and transfer the polluted sludge to sludge storage ponds;

[0007] An electroosmotic component is arranged in the sludge storage tank, and is used for dehydrating and decontaminating the contaminated sludge transferred into the sludge storage tank;

[0008] A vacuum component is arranged in the mud storage tank, and is used to provide a vacuum environment when the electroosmosis component dehydrates and decontaminates the contaminated sludge.

[0009] Preferably, the interior of the sludge storage tank is divided into several treatment chambers by concrete walls, a porous PVC plate is provided at one end of the interior of the treatment chamber, the porous PVC plate and the inner wall of the treatment chamber close to and parallel to it form an anode chamber, a porous steel plate is provided at the other end of the interior of the treatment chamber, the porous steel plate and the inner wall of the treatment chamber close to and parallel to it form a cathode chamber, and each of the treatment chambers is provided with the electroosmosis component and the vacuum component.

[0010] Preferably, the electroosmosis component includes an EKG drainage board, which is arranged between the porous PVC board and the porous steel plate close to one end of the porous PVC board, and the EKG drainage board is electrically connected to the anode of the DC power supply through a wire, and the cathode of the DC power supply is electrically connected to the porous steel plate through the wire.

[0011] Preferably, the side walls of the porous PVC plate and the porous steel plate close to each other are both provided with geotextiles.

[0012] Preferably, the vacuum assembly comprises a vacuum pump, an outlet end of the vacuum pump is fixedly connected to one end of a vacuum pipe, and the other end of the vacuum pipe is connected to the processing chamber.

[0013] Preferably, the dredger is provided with a mud pump, the inlet end of the mud pump extends into the contaminated sludge in the dredger holding tank through a mud inlet pipe, the outlet end of the mud pump is fixedly connected to one end of a conveying pipe, and the other end of the conveying pipe is connected to the treatment chamber.

[0014] Preferably, the anode chamber is filled with a citric acid solution, and the cathode chamber is provided with an automatic water level monitor.

[0015] Preferably, the inner wall of the mud storage tank is provided with a concrete anti-seepage wall.

[0016] Preferably, a mud storage tank cover is provided at the top of the mud storage tank, the part of the mud storage tank cover corresponding to the anode chamber is the anode chamber cover, the part of the mud storage tank cover corresponding to the cathode chamber is the cathode chamber cover, the dredger is connected with the interior of the mud storage tank through the first opening on the mud storage tank cover, and the vacuum component is connected with the interior of the mud storage tank through the second opening on the cathode chamber cover.

[0017] A working method of a vacuum electrochemical in-situ dehydration and decontamination system for heavy metal dredged contaminated sludge, comprising the following steps:

[0018] S1. Build a sludge storage pond beside the river where polluted sludge needs to be treated;

[0019] S2, placing the electroosmosis component and the vacuum component in the mud storage tank and sealing the mud storage tank;

[0020] S3, transferring the polluted sludge to the sludge storage tank by a dredger, and adding an electroosmotic auxiliary solution to the sludge storage tank;

[0021] S4, start the electroosmosis component and the vacuum component to treat the contaminated sludge in the sludge storage tank;

[0022] S5. Repeat S3-S4 until the contaminated sludge is treated.

[0023] Compared with the prior art, the present invention has the following advantages and technical effects:

[0024] 1. The present invention combines vacuum electroosmosis and electric remediation technology, and utilizes vacuum negative pressure, electromigration and electroosmosis to achieve centralized and rapid treatment of sediment consolidation and drainage and pollutant removal;

[0025] 2. The sludge after in-situ dehydration and decontamination can be used as a resource, saving the cost of sludge storage site and reducing the risk of secondary pollution;

[0026] 3. The dredged sludge vacuum electrochemical in-situ dehydration and decontamination system can be reused, which improves the sustainability and economy of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative labor:

[0028] Figure 1 It is an overall schematic diagram of the present invention;

[0029] Figure 2 It is a top view of the mud storage tank of the present invention.

[0030] Among them, 1. dredger; 2. mud pump; 3. conveying pipeline; 4. contaminated sludge; 5. mud storage tank; 6. mud storage tank cover; 7. anode chamber; 8. anode chamber cover; 9. cathode chamber; 10. cathode chamber cover; 11. concrete anti-seepage wall; 12. porous PVC board; 13. porous steel plate; 14. concrete wall; 15. first opening; 16. second opening; 17. EKG drainage board; 18. DC power supply; 19. wire; 20. citric acid solution; 21. vacuum pump; 22. vacuum pipe; 23. geotextile; 24. automatic water level monitoring instrument. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] Reference Figure 1 to Figure 2 As shown, the present invention provides a vacuum electrochemical in-situ dehydration and decontamination system for heavy metal dredged contaminated sludge, comprising

[0034] A dredger 1 is used to collect polluted sludge 4 from a river channel and transfer the polluted sludge 4 to a sludge storage tank 5;

[0035] An electroosmotic component is arranged in the mud storage tank 5, and is used for dehydrating and decontaminating the contaminated sludge 4 transferred to the mud storage tank 5;

[0036] The vacuum component is arranged in the mud storage tank 5, and is used to provide a vacuum environment when the electroosmosis component performs dehydration and decontamination treatment on the contaminated sludge 4.

[0037] According to a further optimization scheme, the interior of the mud storage tank 5 is divided into several treatment chambers by a concrete wall 14, a porous PVC plate 12 is arranged at one end of the interior of the treatment chamber, and the porous PVC plate 12 and the inner wall of the treatment chamber close to and parallel to it form an anode chamber 7, and a porous steel plate 13 is arranged at the other end of the interior of the treatment chamber, and the porous steel plate 13 and the inner wall of the treatment chamber close to and parallel to it form a cathode chamber 9, and each treatment chamber is provided with an electroosmosis component and a vacuum component.

[0038] A further optimized solution is that the electroosmosis component includes an EKG drainage board 17, which is arranged between the porous PVC board 12 and the porous steel board 13 near one end of the porous PVC board 12, and the EKG drainage board 17 is electrically connected to the anode of the DC power supply 18 through the wire 19, and the cathode of the DC power supply 18 is electrically connected to the porous steel plate 13 through the wire 19.

[0039] According to a further optimization scheme, geotextiles 23 are provided on the side walls of the porous PVC plate 12 and the porous steel plate 13 that are close to each other.

[0040] According to a further optimized solution, the vacuum assembly includes a vacuum pump 21, the outlet end of the vacuum pump 21 is fixedly connected to one end of a vacuum pipe 22, and the other end of the vacuum pipe 22 is connected to the processing chamber.

[0041] To further optimize the solution, a mud pump 2 is provided on the dredger 1, the inlet end of the mud pump 2 extends into the contaminated sludge 4 in the holding tank of the dredger 1 through a mud inlet pipe, the outlet end of the mud pump 2 is fixedly connected to one end of a conveying pipe 3, and the other end of the conveying pipe 3 is connected to the processing chamber.

[0042] According to a further optimized solution, the anode chamber 7 is filled with a citric acid solution 20 , and the cathode chamber 9 is provided with an automatic water level monitor 24 .

[0043] To further optimize the solution, a concrete anti-seepage wall 11 is provided on the inner wall of the mud storage tank 5 .

[0044] A further optimized solution is provided with a mud reservoir cover 6 at the top of the mud reservoir 5, the portion of the mud reservoir cover 6 corresponding to the anode chamber 7 is the anode chamber cover 8, the portion of the mud reservoir cover 6 corresponding to the cathode chamber 9 is the cathode chamber cover 10, the dredger 1 is connected with the interior of the mud reservoir 5 through the first opening 15 on the mud reservoir cover 6, and the vacuum component is connected with the interior of the mud reservoir 5 through the second opening 16 on the cathode chamber cover 10.

[0045] A working method of a vacuum electrochemical in-situ dehydration and decontamination system for heavy metal dredged contaminated sludge, comprising the following steps:

[0046] S1. Build a sludge storage pond 5 beside a river where polluted sludge 4 needs to be treated;

[0047] A treatment pool with a length of 1.8 meters, a depth of 1.0 meters, and a width of 3.0 meters was excavated by the river. A 1.0-meter-high, 0.2-meter-thick concrete anti-seepage wall 11 was poured at the bottom and around the treatment pool. A 1.4-meter-long, 1.0-meter-high, 0.2-meter-thick concrete wall 14 was poured every 1.0 meters in the width direction to divide the treatment pool into 3 independent spaces. Each space was divided into sludge storage pools 5, 6, and 7 by burying 1.0-meter-high porous PVC plates 12 and 1.0-meter-high porous steel plates 13. Anode chamber 7 and cathode chamber 9, mud reservoir 5 is 1.0 m long, anode chamber 7 is 0.3 m long, cathode chamber 9 is 0.5 m long, porous steel plate 13 is electrically connected to the cathode of DC power supply 18 through wire 19; EKG drainage board 17 is inserted into each treatment chamber, EKG drainage board 17 is electrically connected to the anode of DC power supply 18 through wire 19, geotextile 23 is laid on porous PVC board 12 and porous steel plate 13, and automatic water level monitor 24 is placed in cathode chamber 9;

[0048] S2, placing the electroosmosis component and the vacuum component in the mud storage tank 5 and sealing the mud storage tank 5;

[0049] The sludge storage tank 5, the anode chamber 7 and the cathode chamber 9 are sealed by the sludge storage tank cover 6, the anode chamber cover 8 and the cathode chamber cover 10, the vacuum pump 21 is connected to the second opening 16 of the cathode chamber cover 10 through the vacuum pipe 22 by a threaded connection, and the delivery pipe 3 is connected to the first opening 15 of the anode chamber cover 8 by a threaded connection;

[0050] S3, transferring the polluted sludge 4 to the sludge storage tank 5 by the dredger 1, and adding an electroosmotic auxiliary solution into the sludge storage tank 5;

[0051] The heavy metal dredged polluted sludge 4 in the river is dredged onto the dredger 1 by the dredger 1; the sludge pump 2 is turned on, and the heavy metal dredged polluted sludge 4 in the dredger 1 is transported to the sludge storage tank 5 through the transport pipeline 3 until the sludge storage tank 5 is filled to 80% of its capacity; the anode chamber cover 8 is opened, and a 1% concentration citric acid solution 20 is injected to 80% of the capacity of the anode chamber 7, and then the anode chamber cover 8 is closed;

[0052] S4, start the electroosmosis component and the vacuum component to treat the contaminated sludge 4 in the sludge storage tank 5;

[0053] Start the vacuum pump 21 and the DC power supply 18. Under the action of vacuum pressure and electric field, the water and pollutants in the heavy metal dredged contaminated sludge 4 migrate from the EKG drainage board 17 to the porous steel plate 13, and flow into the cathode chamber 9 through the holes in the porous PVC plate 12. At the same time, the citric acid solution 20 enters the heavy metal dredged contaminated sludge 4 in the sludge storage tank 5 through the holes in the porous PVC plate 12 under the action of vacuum pressure, thereby improving the conductivity of the soil and forming soluble chelates with heavy metal ions, thereby improving the dehydration and decontamination efficiency. The automatic level monitor 24 monitors the increase of sewage in the cathode chamber 9. When the hourly increase of the sewage level in the cathode chamber 9 is less than 5% of the existing sewage level, it is considered that the treatment process is basically completed, the vacuum pump 21 and the DC power supply 18 are turned off, the cathode chamber cover 10 is opened, and the wastewater is pumped out by a water pump, the anode chamber cover 8 is opened, and the remaining citric acid solution 20 is pumped out by a water pump for subsequent use, the mud storage tank cover 6 is opened, and the treated sludge is excavated and moved to the stacking area or the transport vehicle to ensure the safe transfer and resource utilization of the sludge;

[0054] S5. Repeat S3-S4 until the contaminated sludge 4 is completely treated.

[0055] Repeat S3-S4 until all heavy metal dredged contaminated sludge is treated. 4. After each treatment cycle, check the equipment status and operating parameters, check the sealing of pipes and connectors, and ensure the stable operation of the system and the good condition of the equipment.

[0056] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0057] The embodiments described above are only descriptions of the preferred embodiments of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should fall within the protection scope of the present invention.

Claims

1. A vacuum electrochemical in-situ dehydration and decontamination system for heavy metal dredged contaminated sludge, characterized in that: include A dredger (1) is used to collect polluted sludge (4) from a river channel and transfer the polluted sludge (4) to a sludge storage pond (5); An electroosmotic component is arranged in the sludge storage tank (5), and is used to perform a dehydration and decontamination treatment on the contaminated sludge (4) transferred into the sludge storage tank (5); A vacuum component is arranged in the mud storage tank (5), and is used to provide a vacuum environment when the electroosmosis component performs a dehydration and decontamination treatment on the contaminated sludge (4); The interior of the sludge storage tank (5) is divided into a plurality of treatment chambers by a concrete wall (14), a porous PVC plate (12) is provided at one end of the interior of the treatment chamber, the porous PVC plate (12) and the inner wall of the treatment chamber close to and parallel to it form an anode chamber (7), and a porous steel plate (13) is provided at the other end of the interior of the treatment chamber, the porous steel plate (13) and the inner wall of the treatment chamber close to and parallel to it form a cathode chamber (9), and each of the treatment chambers is provided with the electroosmosis component and the vacuum component; The electroosmotic assembly comprises an EKG drainage plate (17), wherein the EKG drainage plate (17) is arranged between the porous PVC plate (12) and the porous steel plate (13) near one end of the porous PVC plate (12), the EKG drainage plate (17) is electrically connected to the anode of a DC power source (18) via a wire (19), and the cathode of the DC power source (18) is electrically connected to the porous steel plate (13) via the wire (19); The anode chamber (7) is filled with a citric acid solution (20), and the cathode chamber (9) is provided with an automatic water level monitor (24).

2. A heavy metal dredged contaminated sludge vacuum electrochemical in-situ dehydration and decontamination system according to claim 1, characterized in that: The side walls of the porous PVC plate (12) and the porous steel plate (13) that are close to each other are both provided with geotextiles (23).

3. The vacuum electrochemical in-situ dehydration and decontamination system for heavy metal dredged contaminated sludge according to claim 1 is characterized in that: The vacuum component comprises a vacuum pump (21), the outlet end of the vacuum pump (21) being fixedly connected to one end of a vacuum pipeline (22), and the other end of the vacuum pipeline (22) being connected to the processing chamber.

4. The vacuum electrochemical in-situ dehydration and decontamination system for heavy metal dredged contaminated sludge according to claim 1 is characterized in that: The dredger (1) is provided with a mud delivery pump (2), the inlet end of the mud delivery pump (2) extends into the contaminated sludge (4) in the holding tank of the dredger (1) through a mud inlet pipe, the outlet end of the mud delivery pump (2) is fixedly connected to one end of a delivery pipe (3), and the other end of the delivery pipe (3) is connected to the treatment chamber.

5. The vacuum electrochemical in-situ dehydration and decontamination system for heavy metal dredged contaminated sludge according to claim 1 is characterized in that: The inner wall of the mud storage tank (5) is provided with a concrete anti-seepage wall (11).

6. The vacuum electrochemical in-situ dehydration and decontamination system for heavy metal dredged contaminated sludge according to claim 1 is characterized in that: A mud storage tank cover (6) is provided at the top of the mud storage tank (5); the portion of the mud storage tank cover (6) corresponding to the anode chamber (7) is the anode chamber cover (8); the portion of the mud storage tank cover (6) corresponding to the cathode chamber (9) is the cathode chamber cover (10); the dredger (1) is connected to the interior of the mud storage tank (5) through a first opening (15) on the mud storage tank cover (6); and the vacuum component is connected to the interior of the mud storage tank (5) through a second opening (16) on the cathode chamber cover (10).

7. A working method of the vacuum electrochemical in-situ dehydration and decontamination system for heavy metal dredged contaminated sludge according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1. Build a sludge storage pond (5) beside the river where the polluted sludge (4) needs to be treated; S2, placing the electroosmosis component and the vacuum component in the mud storage tank (5) and sealing the mud storage tank (5); S3, transferring the contaminated sludge (4) to a sludge storage tank (5) by means of a dredger (1), and adding an electroosmotic auxiliary solution into the sludge storage tank (5); S4, starting the electroosmosis component and the vacuum component to treat the contaminated sludge (4) in the sludge storage tank (5); S5. Repeat S3-S4 until the contaminated sludge (4) is completely treated.

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