Radial flow type three-dimensional electrode electrolysis reactor for underground water treatment and construction method

Abstract

The invention discloses a radial-flow type three-dimensional electrode electrolysis reactor for underground water treatment and a construction method of the radial-flow type three-dimensional electrode electrolysis reactor. The reactor comprises a reaction bin and a sewage pipe located in the center of the interior of the reaction bin, a plurality of radial flow electrode plates radiating outwards are arranged on the outer portion of the sewage pipe in the circumferential direction at equal intervals in a surrounding mode, a plurality of water outlet holes are formed in the positions, corresponding to the radial flow electrode plates, of the outer wall of the lower portion of the sewage pipe, and the interior of the reaction bin is filled with activated carbon carrier electrode particles loaded with Cu-Ce. The method comprises the steps of S1, sewage injection, S2, particle electrode injection and S3, circular treatment. The three-dimensional electrode is constructed, so that a micro electric field is formed between the cathode and the anode, the mass transfer distance between free radicals and organic matters is greatly shortened, and meanwhile, attachment sites are provided for catalytic active components, so that the active components participate in dissociation of the free radicals and oxidation-reduction reaction of the organic matters; and the reaction rate of the electro-catalysis reaction and the treatment efficiency of the electro-catalysis process are greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of groundwater treatment, and in particular to a radial flow three-dimensional electrode electrolysis reactor for groundwater treatment and a construction method thereof. Background Art

[0002] In recent years, with the continuous optimization of the country's industrial structure, many chemical companies have been shut down and renovated, and the pollution of soil and groundwater at the original site of the factory has become increasingly prominent. In addition, due to the leakage of underground oil storage tanks and the widespread use of organic substances, various organic daily necessities and chemical products will produce toxic and difficult-to-decompose pollutants during production, which has aggravated the phenomenon of organic pollutants entering the soil and groundwater, causing the soil and groundwater environment to gradually deteriorate. Among them, some organic pollutants such as VOCs are highly volatile and not easily soluble in water. They mainly exist in the form of non-aqueous phase liquid (NAPL) in media such as groundwater or soil, and form an immiscible multiphase flow system with other phases. In the underground medium environment, mass transfer occurs between the NAPL phase, liquid phase, solid phase and gas phase through dissolution, adsorption, volatilization, etc., making it difficult to be treated.

[0003] At present, the commonly used methods for the treatment of produced groundwater include advanced oxidation processes, including photochemical oxidation, Fenton process, ozone catalytic oxidation and electrocatalytic oxidation. The principle of electrocatalytic reduction is similar to that of electrocatalytic oxidation, which is divided into direct reaction and indirect reaction, that is, the pollutants are transferred to the electrode surface for electrochemical reaction, or the electrode produces active groups that enter the water body and react with pollutants. Due to the diversity of chlorinated organic matter, there will be more complex by-products in the dechlorination process, such as organic intermediates, chlorine oxygen-containing acids, etc., and some by-products cannot be completely removed by the process of treating target pollutants, so dechlorination by-products and degradation pathways are also one of the hot spots in electrocatalytic research.

[0004] The three-dimensional electrode structure was proposed in the 1960s. Granular or debris-like particle electrodes were added between the traditional anode and the traditional cathode. Due to electrostatic induction, the two ends of the particles carried positive and negative charges respectively. Multiple tiny electrodes could be constructed, shortening the mass transfer distance of free radicals and organic matter, forming a three-dimensional reaction system, and providing attachment sites for catalytic active components.

[0005] At present, there have been many studies on the equipment of the electrocatalytic oxidation method. Some people have improved the structure of the electrolytic cell or the electrode plate, or added some auxiliary means to improve the electrolysis efficiency. For example, the invention patent with the patent publication number CN104372375A has disclosed a water electrolyzer device that can accelerate the separation of oxygen / hydrogen from the electrode plate, which includes a water electrolyzer body, the water electrolyzer body has a storage space for accommodating electrolyte and is equipped with electrodes and electrode plates, and the water electrolyzer device is also provided with a power control unit and an ultrasonic vibration mechanism connected thereto. The invention adds a power control unit and an ultrasonic vibration mechanism to the water electrolyzer. The power control unit can monitor the current and voltage loaded on the electrode plate in real time, and supply the most suitable voltage and current to the electrode plate according to its feedback results, so that the electrolysis reaction reaches the best state and increases the amount of bubbles on the surface of the electrode plate; at the same time, the ultrasonic vibration mechanism transmits the vibration to the electrode plate in the form of ultrasonic waves, so that the electrode plate vibrates, so that the bubbles adhering thereto are forced to vibrate and quickly detach and float, accelerating the generation of oxygen and hydrogen mixed gas, and making it more convenient to use the mixed gas. However, the single method of applying ultrasound has limited effect on improving the efficiency of electrocatalytic oxidation and currently only applies to two-dimensional electrodes, but further research is needed on three-dimensional electrodes. Summary of the invention

[0006] In view of the above-mentioned problems, the present invention provides a radial flow three-dimensional electrode electrolysis reactor for groundwater treatment and a construction method thereof.

[0007] The technical solution of the present invention is:

[0008] A radial flow three-dimensional electrode electrolysis reactor for groundwater treatment, comprising a reaction chamber, a sewage pipe located at the center of the reaction chamber, a plurality of radial flow electrode plates radiating outwards arranged at equal intervals around the outside of the sewage pipe, and a plurality of water outlet holes arranged on the lower outer wall of the sewage pipe at positions corresponding to the radial flow electrode plates;

[0009] A plurality of slots are provided on the inner side of the radial current electrode plate, and a group of stirring plates are provided corresponding to each of the slots. The stirring plates include a plurality of stirring plates arranged at equal intervals in the circumferential direction. Each stirring plate on the same stirring plate group is fixedly connected by a rotating ring, and the rotating ring is rotatably sleeved on the outside of the sewage pipe. Each rotating ring is driven to rotate synchronously by a driving motor;

[0010] The top of the reaction chamber is provided with a top cover, the middle of the top cover is provided with an opening, the sewage pipe runs through the opening, a first water outlet pipe is provided on the side wall of the reaction chamber near the bottom of the top cover, the end of the first water outlet pipe is connected to a water pump, the water outlet end of the water pump is provided with a return pipe, and the return pipe is connected to the top of the sewage pipe;

[0011] The reaction chamber is filled with particle electrodes, and a feeding pipe is arranged on one side of the upper part of the reaction chamber.

[0012] Furthermore, each of the rotating rings is fixedly connected by two symmetrically arranged first connecting rods, the first connecting rods extend to the outer side of the upper part of the reaction chamber, and a second connecting rod is provided at the end of each first connecting rod. A turntable is commonly connected to the end of each second connecting rod, and the center of the turntable coincides with the center of the sewage pipe. A limit block is provided on the inner wall of the rotating ring, and the limit block is slidably connected to a limit groove corresponding to the outer wall of the sewage pipe.

[0013] Description: The rotating ring is controlled by the first connecting rod and the second connecting rod, so that it can rotate under the drive of the turntable, and the limit block and the limit groove maintain its stability during rotation.

[0014] Furthermore, the outer wall of the turntable is provided with a tooth groove, and a driving gear is meshed and connected to one side of the outer wall of the turntable through the tooth groove. The driving gear is driven to rotate by the driving motor, and the rear side of the driving motor is fixedly connected to the external wall through a fixing rod.

[0015] Description: The turntable is driven to rotate through the cooperation of the tooth groove and the driving gear.

[0016] Furthermore, a plurality of support blocks of the same height are evenly spaced at the bottom of the turntable, the tops of the support blocks are slidably connected to the slide grooves provided at the bottom of the turntable, and the support blocks are fixedly arranged on the upper surface of the top cover.

[0017] Note: The support blocks are used to maintain the stability of the turntable when it rotates.

[0018] Furthermore, there are 6 to 8 radial current electrode plates, there are 3 stirring plate groups, and there are 4 to 6 stirring plates on each stirring plate group.

[0019] Description: By optimizing and adjusting the number of radial flow electrode plates, the treatment effect on contaminated groundwater can be further improved. Generally, the more electrode plates are set, the greater the current and the better the treatment effect. However, in the present invention, setting too many radial flow electrode plates will cause the temperature to rise, the rotation efficiency to decrease, and the failure rate to increase. Therefore, it is necessary to set their number reasonably; the setting of the stirring plate group is similar. If too many are set, a larger space will be occupied, thereby compressing the movement space of the activated carbon carrier electrode particles. If too few are set, the stirring effect cannot be well achieved.

[0020] Furthermore, the water outlet holes distributed between two adjacent rotating rings have the same aperture diameter. According to the position distribution of the water outlet holes, a first water outlet area is formed between the rotating ring located at the top and the rotating ring located in the middle, a second water outlet area is formed between the rotating ring located in the middle and the rotating ring located at the bottom, and a third water outlet area is formed below the rotating ring located at the bottom. The aperture diameter of the water outlet holes gradually decreases from the first water outlet area to the third water outlet area. The aperture diameter of the water outlet holes in the first water outlet area is 20-30 mm, the aperture diameter of the water outlet holes in the second water outlet area is 10-20 mm, and the aperture diameter of the water outlet holes in the third water outlet area is 5-10 mm.

[0021] Note: By dividing the water outlet areas into multiple areas and optimizing the distribution of the water outlet hole diameters, the water can be discharged more evenly. As the water naturally flows downward, the water outlets at the lower water outlets have a longer contact time with the electrode plate. Therefore, the water outlet holes are designed to have a gradually decreasing diameter from top to bottom, distributing more water in the upper half of the radial flow electrode plate, thereby increasing the contact time between the water flow and pollutants and the electrode plate and improving the treatment efficiency.

[0022] Furthermore, a second water outlet pipe and an air duct are provided on the side wall at the bottom of the reaction chamber, a foam outlet is provided on one side of the top cover, the power cords provided on the sides of the radial flow electrode plates are all connected to an external power supply after passing through the top cover, a fixing block is provided at the bottom of the radial flow electrode plate, a fixing groove provided inside the fixing block is clamped with the bottom of the radial flow electrode plate, and the rear side wall of the fixing block is fixedly connected to the inner wall of the reaction chamber.

[0023] Note: The stability of the radial current electrode plate during operation is maintained by setting the fixing block.

[0024] Furthermore, the particle electrode is an activated carbon carrier electrode particle loaded with Cu-Ce, and the preparation method of the activated carbon carrier electrode particle loaded with Cu-Ce is:

[0025] S1. Pretreatment: Take the activated carbon powder and wash it with deionized water three times, immerse it completely in a hydrochloric acid solution with a molar concentration of 1 mol / L, ultrasonically treat it for 30 to 40 minutes, soak it for 1 to 2 hours, take it out, wash it with deionized water until the pH is neutral, dry it in an oven at 100 to 105°C for 1 to 2 hours, and take out the pretreated activated carbon powder for use;

[0026] S2. Cu-Ce loading: Mix Cu(NO3)2 solution and Ce(NO3)2 solution with molar concentration of 40-50 mmol / L in a weight ratio of 1:1 to obtain an impregnation salt solution, and immerse the pretreated activated carbon powder in the impregnation salt solution for 20-24 hours, then place it in an oven at 100-105°C for drying for 1-2 hours, and then place it in a muffle furnace for calcination at 500-550°C for 2-3 hours. After taking it out, wash it three times with deionized water, place it in an oven at 100-105°C for drying for 1-2 hours, and obtain activated carbon carrier electrode particles loaded with Cu-Ce after cooling.

[0027] Description: Through the preferred Cu-Ce loaded activated carbon carrier electrode particles, the Cu and Ce bimetallics have a bimetallic synergistic effect and have excellent catalytic activity, which has a significant enhancement effect on the effect of electrocatalytic oxidation treatment of organic wastewater.

[0028] Furthermore, in S1, the particle size of the activated carbon powder is less than 50 μm, the ultrasonic power is 80-100 Hz, and the weight ratio of the activated carbon powder to the hydrochloric acid is 1:1-2.

[0029] Description: Ultrasonic treatment is used to promote the acid washing effect on activated carbon powder.

[0030] On the other hand, the present invention also provides a method for constructing a radial flow three-dimensional electrode electrolysis reactor for groundwater treatment, comprising the following steps:

[0031] S1. Sewage injection: The sewage to be treated is injected into the sewage pipe and enters the reaction chamber through the outlet hole (21) on the sewage pipe. Then, the radial flow electrode plate is energized so that the sewage flows out from the center to the outside in a radial flow pattern. The current density is adjusted to 70-100 A / m 2 ;

[0032] S2. Particle electrode injection: Add particle electrodes into the reaction chamber through the feeding tube, with the added amount being 200-240 g / L of sewage;

[0033] S3, circulation treatment: turn on the water pump to extract the sewage that rises to the first outlet pipe, and re-inject it into the sewage pipe through the reflux pipe to form a continuous circulation treatment. The hydraulic retention time is 40 to 100 minutes, and the water pump flow rate is 1 to 3L / h.

[0034] The beneficial effects of the present invention are:

[0035] (1) The present invention constructs a three-dimensional electrode by adding Cu-Ce-loaded activated carbon carrier electrode particles into a radial flow electrolyzer, thereby forming a micro-electric field between the anode and cathode, greatly shortening the mass transfer distance between free radicals and organic matter, and providing attachment sites for catalytic active components, so that the active components participate in the dissociation of free radicals and the redox reaction of organic matter, greatly improving the reaction rate of the electrocatalytic reaction and the processing efficiency of the electrocatalytic process, thereby effectively solving the problem of large electrode plate spacing at a radial flow electrolyzer reactor far away from the water inlet pipe, and providing a solution to reduce the cost of electrocatalytic electrode materials.

[0036] (2) The present invention arranges the radial flow electrode plates in a radial shape in the reaction chamber, which can effectively utilize the electrode area and improve the treatment effect. At the same time, the rotatable stirring plate group increases the sewage flow rate when it rotates continuously, promotes the contact efficiency between the Cu-Ce-loaded activated carbon carrier electrode particles and the sewage, improves the convective mass transfer of pollutants to the radial flow electrode plates, and enhances the treatment effect.

[0037] (3) The present invention also improves and innovates the particle electrode of the prior art, and prepares Cu-Ce loaded activated carbon carrier electrode particles to replace the particle electrode of the prior art. The Cu and Ce bimetallics therein have a bimetallic synergistic effect and have excellent catalytic activity. They have a significant enhancing effect on the effect of electrocatalytic oxidation treatment of organic wastewater and have good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic diagram of the overall structure of a radial flow three-dimensional electrode electrolysis reactor for groundwater treatment according to the present invention;

[0039] Figure 2 This is a front view of a radial flow three-dimensional electrode electrolysis reactor for groundwater treatment according to the present invention;

[0040] Figure 3 It is a schematic diagram of the internal structure of a radial flow three-dimensional electrode electrolysis reactor for groundwater treatment according to the present invention;

[0041] Figure 4 It is a top view of a radial flow three-dimensional electrode electrolysis reactor for groundwater treatment of the present invention;

[0042] Figure 5 It is a schematic structural diagram of a water outlet hole on a sewage pipe of a radial flow three-dimensional electrode electrolysis reactor for groundwater treatment according to the present invention;

[0043] Figure 6 It is a schematic diagram of the connection structure between the radial flow electrode plate and the fixed block of a radial flow type three-dimensional electrode electrolysis reactor for groundwater treatment of the present invention;

[0044] Figure 7It is a schematic diagram of the connection structure of the limit block and the limit groove of a radial flow type three-dimensional electrode electrolysis reactor for groundwater treatment of the present invention;

[0045] Figure 8 The present invention is a schematic diagram of the connection structure between a turntable and a driving gear of a radial flow three-dimensional electrode electrolysis reactor for groundwater treatment.

[0046] Among them, 1-reaction chamber, 11-first water outlet pipe, 12-feeding pipe, 13-second water outlet pipe, 14-air guide pipe, 2-sewage pipe, 21-water outlet hole, 22-limiting groove, 3-radial flow electrode plate, 31-slot, 32-power cord, 33-fixing block, 34-fixing groove, 4-stirring plate group, 41-stirring plate, 42-rotating ring, 43-first connecting rod, 44-second connecting rod, 45-limiting block, 5-driving motor, 51-driving gear, 52-fixing rod, 6-top cover, 61-opening, 62-foam outlet, 7-water pump, 71-reflux pipe, 8-turntable, 81-tooth groove, 82-support block, 83-slide. DETAILED DESCRIPTION

[0047] Example 1

[0048] like Figure 1 and Figure 3 As shown, a radial flow three-dimensional electrode electrolysis reactor for groundwater treatment includes a reaction chamber 1, a sewage pipe 2 located at the center of the reaction chamber 1, 8 radial flow electrode plates 3 radiating outward are arranged around the sewage pipe 2 at equal intervals in the circumferential direction, and a plurality of water outlet holes 21 are arranged on the lower outer wall of the sewage pipe 2 corresponding to the positions of the radial flow electrode plates 3;

[0049] like Figure 2 to Figure 4 , Figure 7 As shown, three slots 31 are provided on the inner side of the radial current electrode plate 3, and a group of stirring plate groups 4 are provided corresponding to each slot 31. The stirring plate group 4 includes four stirring plates 41 arranged at equal intervals in the circumferential direction. The stirring plates 41 on the same stirring plate group 4 are fixedly connected by a rotating ring 42, and the rotating ring 42 is rotatably sleeved on the outside of the sewage pipe 2. The rotating rings 42 are fixedly connected by two symmetrically arranged first connecting rods 43. The first connecting rods 43 extend to the outer side of the upper part of the reaction chamber 1. The ends of the first connecting rods 43 are provided with second connecting rods 44. The ends of the second connecting rods 44 are commonly connected with a turntable 8. The center of the turntable 8 coincides with the center of the sewage pipe 2. A limit block 45 is provided on the inner wall of the rotating ring 42. The limit block 45 is slidably connected to the limit groove 22 corresponding to the outer wall of the sewage pipe 2.

[0050] like Figure 3 and Figure 8As shown, each rotating ring 42 is driven to rotate synchronously by a driving motor 5, a tooth groove 81 is provided on the outer wall of the turntable 8, a driving gear 51 is meshed and connected to one side of the outer wall of the turntable 8 through the tooth groove 81, and the driving gear 51 is driven to rotate by the driving motor 5, the driving motor 5 is a commercially available gear reduction motor, and the rear side of the driving motor 5 is fixedly connected to the external wall through a fixing rod 52, and a plurality of support blocks 82 of the same height are evenly spaced at the bottom of the turntable 8, and the top of the support block 82 is slidably connected to a slide groove 83 provided at the bottom of the turntable 8, and the support block 82 is fixedly arranged on the upper surface of the top cover 6;

[0051] like Figure 3 and Figure 5 As shown, the apertures of the water outlet holes 21 distributed between two adjacent rotating rings 42 are the same. According to the position distribution of the water outlet holes 21, a first water outlet area is formed between the rotating ring 42 located at the top and the rotating ring 42 located in the middle, a second water outlet area is formed between the rotating ring 42 located in the middle and the rotating ring 42 located below, and a third water outlet area is formed below the rotating ring 42 located below. The apertures of the water outlet holes 21 gradually decrease from the first water outlet area to the third water outlet area. The apertures of the water outlet holes 21 in the first water outlet area are 25 mm, the apertures of the water outlet holes 21 in the second water outlet area are 15 mm, and the apertures of the water outlet holes 21 in the third water outlet area are 8 mm.

[0052] A top cover 6 is provided on the top of the reaction chamber 1, an opening 61 is provided in the middle of the top cover 6, the sewage pipe 2 passes through the opening 61, a first water outlet pipe 11 is provided on the side wall of the reaction chamber 1 near the bottom of the top cover 6, a water pump 7 is connected to the end of the first water outlet pipe 11, a return pipe 71 is provided at the water outlet end of the water pump 7, and the return pipe 71 is connected to the top of the sewage pipe 2;

[0053] like Figure 3 and Figure 6 As shown, the power lines 32 provided on the side of the radial current electrode plate 3 are all connected to the external power supply after passing through the top cover 6, and the bottom of the radial current electrode plate 3 is provided with a fixing block 33, and the fixing groove 34 provided inside the fixing block 33 is clamped with the bottom of the radial current electrode plate 3, and the rear side wall of the fixing block 33 is fixedly connected to the inner wall of the reaction chamber 1

[0054] like Figure 1 and Figure 2 As shown, the reaction chamber 1 is filled with a particle electrode, which is activated carbon powder. The particle size of the activated carbon powder is less than 50 μm. A feeding pipe 12 is provided on one side of the upper portion of the reaction chamber 1. A second water outlet pipe 13 and an air duct 14 are provided on the bottom side wall of the reaction chamber 1. A foam outlet 62 is provided on one side of the top cover 6.

[0055] Example 2

[0056] The difference between this embodiment and embodiment 1 is that:

[0057] Six radial flow electrode plates 3 radiating outward are arranged around the outside of the sewage pipe 2 at equal intervals in the circumferential direction, and the stirring plate group 4 includes four stirring plates 41 arranged at equal intervals in the circumferential direction.

[0058] Example 3

[0059] The difference between this embodiment and embodiment 1 is that:

[0060] The aperture size distribution of the water outlet holes 21 in the first water outlet area is 20 mm, the aperture size distribution of the water outlet holes 21 in the second water outlet area is 10 mm, and the aperture size distribution of the water outlet holes 21 in the third water outlet area is 5 mm.

[0061] Example 4

[0062] The difference between this embodiment and embodiment 1 is that:

[0063] The aperture size distribution of the water outlet holes 21 in the first water outlet area is 30 mm, the aperture size distribution of the water outlet holes 21 in the second water outlet area is 20 mm, and the aperture size distribution of the water outlet holes 21 in the third water outlet area is 10 mm.

[0064] Note: When the volume of contaminated groundwater to be treated is larger, the aperture of the water outlet hole 21 is larger, and the aperture distribution of the three water outlet areas should be proportional. The parameters in Example 1 or Examples 3 to 4 are reasonably selected according to the volume of contaminated groundwater to be treated.

[0065] Example 5

[0066] The difference between this embodiment and embodiment 1 is that the particle electrode is an activated carbon carrier electrode particle loaded with Cu-Ce, and the preparation method of the activated carbon carrier electrode particle loaded with Cu-Ce is:

[0067] S1. Pretreatment: Take activated carbon powder and wash it three times with deionized water. The particle size of the activated carbon powder is less than 50 μm. It is completely immersed in a hydrochloric acid solution with a molar concentration of 1 mol / L. The weight ratio of activated carbon powder to hydrochloric acid is 1:1. After ultrasonic treatment for 30 minutes, continue to soak for 1 hour and then take it out. The ultrasonic power is 80 Hz. Wash it with deionized water until the pH is neutral. Place it in a 100°C oven and dry it for 1 hour. Take out the pretreated activated carbon powder for use;

[0068] S2. Cu-Ce loading: Mix Cu(NO3)2 solution and Ce(NO3)2 solution with molar concentration of 40 mmol / L in a weight ratio of 1:1 to obtain an impregnation salt solution. Immerse the pretreated activated carbon powder in the impregnation salt solution for 20 hours, then dry it in an oven at 100°C for 1 hour, and then calcine it in a muffle furnace at 500°C for 2 hours. After taking it out, wash it three times with deionized water, dry it in an oven at 100°C for 1 hour, and obtain activated carbon carrier electrode particles loaded with Cu-Ce after cooling.

[0069] Example 6

[0070] The difference between this embodiment and embodiment 5 is that the particle electrode is an activated carbon carrier electrode particle loaded with Cu-Ce, and the preparation method of the activated carbon carrier electrode particle loaded with Cu-Ce is:

[0071] S1. Pretreatment: Take activated carbon powder and wash it three times with deionized water. The particle size of the activated carbon powder is less than 50 μm. It is completely immersed in a hydrochloric acid solution with a molar concentration of 1 mol / L. The weight ratio of activated carbon powder to hydrochloric acid is 1:2. After ultrasonic treatment for 40 minutes, continue to soak for 2 hours and then take it out. The ultrasonic power is 100 Hz. Wash it with deionized water until the pH is neutral. Place it in a 105°C oven and dry it for 2 hours. Take out the pretreated activated carbon powder for use;

[0072] S2. Cu-Ce loading: Mix Cu(NO3)2 solution and Ce(NO3)2 solution with molar concentration of 50 mmol / L in a weight ratio of 1:1 to obtain an impregnation salt solution. Immerse the pretreated activated carbon powder in the impregnation salt solution for 24 hours, then dry it in an oven at 105°C for 2 hours, and then calcine it in a muffle furnace at 550°C for 3 hours. After taking it out, wash it three times with deionized water, dry it in an oven at 105°C for 2 hours, and obtain activated carbon carrier electrode particles loaded with Cu-Ce after cooling.

[0073] Note: In Examples 5 and 6, the selected parameters are all routine adjustments within a reasonable range. Any set of parameters selected in Examples 5 and 6 can achieve similar technical effects. In the future, we will further study the effects of the concentration of the impregnating salt solution and the calcination temperature.

[0074] Example 7

[0075] This embodiment describes a method for constructing a radial flow three-dimensional electrode electrolysis reactor for groundwater treatment according to embodiment 5, comprising the following steps:

[0076] S1. Sewage injection: The sewage to be treated is injected into the sewage pipe 2, and enters the reaction chamber 1 through the water outlet 21 on the sewage pipe 2. Then, the radial flow electrode plate 3 is energized to form a radial flow pattern from the center to the outside when the sewage flows out. The current density is adjusted to 80A / m 2 ;

[0077] S2, particle electrode injection: add particle electrodes into the reaction chamber 1 through the feeding pipe 12, and the added amount is 220g / L sewage;

[0078] S3, circulation treatment: turn on the water pump 7 to extract the sewage that rises to the first outlet pipe 11, and re-inject it into the sewage pipe 2 through the reflux pipe 71 to form a continuous circulation treatment. The hydraulic retention time is 60 minutes, and the flow rate of the water pump 7 is 2L / h.

[0079] Example 8

[0080] The difference between this embodiment and embodiment 7 is that:

[0081] S1. Sewage injection: The sewage to be treated is injected into the sewage pipe 2, and enters the reaction chamber 1 through the water outlet 21 on the sewage pipe 2. Then, the radial flow electrode plate 3 is energized to form a radial flow pattern from the center to the outside when the sewage flows out. The current density is adjusted to 70A / m 2 ;

[0082] S2, particle electrode injection: add particle electrodes into the reaction chamber 1 through the feeding pipe 12, and the added amount is 200g / L sewage;

[0083] S3, circulation treatment: start the water pump 7 to extract the sewage that rises to the first outlet pipe 11, and re-inject it into the sewage pipe 2 through the return pipe 71 to form a continuous circulation treatment. The hydraulic retention time is 40 minutes, and the flow rate of the water pump 7 is 1L / h.

[0084] Example 9

[0085] The difference between this embodiment and embodiment 7 is that:

[0086] S1. Sewage injection: The sewage to be treated is injected into the sewage pipe 2, and enters the reaction chamber 1 through the water outlet 21 on the sewage pipe 2. Then, the radial flow electrode plate 3 is energized to form a radial flow pattern from the center to the outside when the sewage flows out. The current density is adjusted to 100A / m 2 ;

[0087] S2, particle electrode injection: add particle electrodes into the reaction chamber 1 through the feeding pipe 12, and the added amount is 240g / L sewage;

[0088] S3, circulation treatment: turn on the water pump 7 to extract the sewage that rises to the first outlet pipe 11, and re-inject it into the sewage pipe 2 through the return pipe 71 to form a continuous circulation treatment. The hydraulic retention time is 100 minutes and the flow rate of the water pump 7 is 3L / h.

[0089] Note: In Examples 8 and 9, optimization is mainly performed for different sewage volumes. When the sewage volume is large, the parameters in Example 9 are selected, and when the sewage volume is small, the parameters in Example 8 are selected.

[0090] Working principle:

[0091] Next, we further illustrate the working principle of a radial flow three-dimensional electrode electrolysis reactor for groundwater treatment of the present invention in combination with the construction method in Example 5.

[0092] When performing S3 circulation treatment, it is necessary to rotate the stirring plate group 4 to improve the contact efficiency between the activated carbon carrier electrode particles loaded with Cu-Ce and the sewage, turn on the driving motor 5 to drive the driving gear 51 to rotate, thereby driving the turntable 8 to rotate under the meshing action of the tooth groove 81, so that it drives each rotating ring 42 to rotate through the second connecting rod 44 and the first connecting rod 43, and at the same time, the limit block 45 rotates in the limit groove 22 to maintain the overall stability of each rotating ring 42 and the stirring plate group 4, and at the same time, the rotation and stirring of each stirring plate 41 can be realized, and when the stirring plate 41 rotates, it avoids affecting the radial flow electrode plate 3 through the groove 31.

[0093] Experimental Example 1

[0094] Next, we test the actual sewage treatment effect of a radial flow three-dimensional electrode electrolytic reactor for groundwater treatment in Example 5 of the present invention, and compare it with an ordinary electrolytic cell reactor. The ordinary electrolytic cell reactor of Comparative Example 1 is only provided with the same radial flow electrode plate 3 as in Example 1, without adding Cu-Ce loaded activated carbon carrier electrode particles. The detection method is: qualitative and semi-quantitative analysis of the sample to be tested is performed by 7890B gas chromatography-2YF-DC-019 mass spectrometry, and the detected compounds are automatically identified by Masshunter software, and the matching degree is higher than 80%; according to the "Water and Wastewater Detection and Analysis Methods (Fourth Edition)", the metal ion content in the solution is determined by iCAP7400DuoMFC inductively coupled plasma emission spectrometer. The results are shown in Table 1.

[0095] Table 1 Comparison of the treatment results of the present invention and the comparative example

[0096]

[0097] It can be seen that the reactor of the present invention has significantly improved the COD removal rate of contaminated groundwater. At the same time, the electrode plate area used to treat unit volume of wastewater is greatly reduced, and the power consumption for treating the same volume of contaminated groundwater is slightly higher than that of the ordinary electrolyzer reactor.

[0098] Experimental Example 2

[0099] Next, we test the actual sewage treatment effect of a radial flow three-dimensional electrode electrolysis reactor for groundwater treatment in Example 5 of the present invention, and conduct an in-depth study on the influence of the concentration of the mixed salt solution. In Comparative Example 2, the molar concentration of the mixed salt solution is 0.5 mmol / L, and the molar concentration of the mixed salt solution in Comparative Example 3 is 15 mmol / L. The results are shown in Table 2.

[0100] Table 2 Comparison of the treatment results of the present invention and the comparative example

[0101] Case COD removal rate % The present invention 92.39 Comparative Example 2 85.25 Comparative Example 3 86.37

[0102] It can be observed that in the range of 0-50 mmol / L, as the impregnation concentration of the particle electrode preparation increases, due to the Cu 2+ and Ce 3+ As the content of active components increases, the catalytic ability of the particle electrode is enhanced, and the COD removal rate increases. When the impregnation concentration reaches 50mmol / L. Cu 2+ The leaching concentration reaches a certain level. Continuing to increase the leaching concentration will cause Cu 2+ Leaching is more serious. Excessive leaching concentration will cause the loss of active components, resulting in unstable catalytic effect, and on the other hand, the leached metal ions will cause secondary pollution to the target water body. Therefore, 50mmol / L is selected as the optimal immersion concentration.

[0103] Example 3

[0104] Next, we test the actual sewage treatment effect of a radial flow three-dimensional electrode electrolysis reactor for groundwater treatment in Example 5 of the present invention, and conduct an in-depth study on the influence of calcination temperature. In Comparative Example 4, the calcination temperature is 400°C, and in Comparative Example 5, the calcination temperature is 600°C. The results are shown in Table 3.

[0105] Table 3 Comparison of the treatment results of the present invention and the comparative example

[0106] Case COD removal rate % The present invention 92.39 Comparative Example 4 90.75 Comparative Example 5 91.21

[0107] It can be observed that when the calcination temperature is between 400℃ and 500℃, as the temperature increases, Cu 2+ and Ce 3+ The binding ability with the activated carbon surface is enhanced, the catalytic degradation effect is significantly improved, and the leaching concentration is reduced; above 500℃, as the temperature increases, the COD removal effect decreases, and Cu 2+ The leaching concentration increased slightly, which may be due to the structural collapse at high temperature and the shedding of active metal oxides on the surface, which made Cu 2+ and Ce 3+ The catalytic ability of the active components is weakened. The experimental phenomena and the optimum temperature range are close to those described in the literature. Therefore, 500°C is selected as the optimal temperature for calcining activated carbon.

Claims

1. A radial flow three-dimensional electrode electrolysis reactor for groundwater treatment, characterized in that: It comprises a reaction chamber (1), a sewage pipe (2) located at the center of the reaction chamber (1), a plurality of radial flow electrode plates (3) radiating outwards are arranged at equal intervals around the outside of the sewage pipe (2), and a plurality of water outlet holes (21) are arranged on the lower outer wall of the sewage pipe (2) at positions corresponding to the radial flow electrode plates (3); The radial current electrode plate (3) is provided with a plurality of slots (31) on the inner side, and a group of stirring plate groups (4) are provided corresponding to each of the slots (31), and the stirring plate group (4) includes a plurality of stirring plates (41) arranged at equal intervals in the circumferential direction, and each of the stirring plates (41) on the same stirring plate group (4) is fixedly connected via a rotating ring (42), and the rotating ring (42) is rotatably sleeved on the outside of the sewage pipe (2), and each of the rotating rings (42) is driven to rotate synchronously by a driving motor (5); The top of the reaction chamber (1) is provided with a top cover (6), the middle of the top cover (6) is provided with an opening (61), the sewage pipe (2) passes through the opening (61), a first water outlet pipe (11) is provided on the side wall of the reaction chamber (1) near the bottom of the top cover (6), the end of the first water outlet pipe (11) is connected to a water pump (7), the water outlet end of the water pump (7) is provided with a return pipe (71), and the return pipe (71) is connected to the top of the sewage pipe (2); The reaction chamber (1) is filled with particle electrodes, and a feeding pipe (12) is provided on one side of the upper part of the reaction chamber (1).

2. The radial flow three-dimensional electrode electrolysis reactor for groundwater treatment according to claim 1, characterized in that: Each of the rotating rings (42) is fixedly connected by two symmetrically arranged first connecting rods (43), the first connecting rods (43) extending to the outer side of the upper part of the reaction chamber (1), the end of each first connecting rod (43) is provided with a second connecting rod (44), the end of each second connecting rod (44) is commonly connected to a rotating disk (8), the center of the rotating disk (8) coincides with the center of the sewage pipe (2), a limit block (45) is provided on the inner wall of the rotating ring (42), and the limit block (45) is slidably connected to a limit groove (22) correspondingly provided on the outer wall of the sewage pipe (2).

3. The radial flow three-dimensional electrode electrolysis reactor for groundwater treatment according to claim 2, characterized in that: The outer wall of the turntable (8) is provided with a tooth groove (81), and a driving gear (51) is meshedly connected to one side of the outer wall of the turntable (8) through the tooth groove (81); the driving gear (51) is driven to rotate by the driving motor (5), and the rear side of the driving motor (5) is fixedly connected to the external wall through a fixing rod (52).

4. The radial flow three-dimensional electrode electrolysis reactor for groundwater treatment according to claim 2, characterized in that: A plurality of support blocks (82) of the same height are arranged at equal intervals at the bottom of the turntable (8); the top of the support block (82) is slidably connected to a slide groove (83) arranged at the bottom of the turntable (8); and the support block (82) is fixedly arranged on the upper surface of the top cover (6).

5. The radial flow three-dimensional electrode electrolysis reactor for groundwater treatment according to claim 1, characterized in that: The number of the radial current electrode plates (3) is 6 to 8, the number of the stirring plate groups (4) is 3, and the number of the stirring plates (41) on each stirring plate group (4) is 4 to 6.

6. A radial flow three-dimensional electrode electrolysis reactor for groundwater treatment according to claim 5, characterized in that: The water outlet holes (21) distributed between two adjacent rotating rings (42) have the same aperture. According to the position distribution of the water outlet holes (21), a first water outlet area is formed between the rotating ring (42) located at the top and the rotating ring (42) located in the middle, a second water outlet area is formed between the rotating ring (42) located in the middle and the rotating ring (42) located at the bottom, and a third water outlet area is formed below the rotating ring (42) located at the bottom. The apertures of the water outlet holes (21) gradually decrease from the first water outlet area to the third water outlet area. The apertures of the water outlet holes (21) in the first water outlet area are distributed in a range of 20 to 30 mm, the apertures of the water outlet holes (21) in the second water outlet area are distributed in a range of 10 to 20 mm, and the apertures of the water outlet holes (21) in the third water outlet area are distributed in a range of 5 to 10 mm.

7. The radial flow three-dimensional electrode electrolysis reactor for groundwater treatment according to claim 1, characterized in that: The bottom side wall of the reaction chamber (1) is provided with a second water outlet pipe (13) and an air guide pipe (14); one side of the top cover (6) is provided with a foam outlet (62); the power lines (32) provided on the sides of the radial flow electrode plates (3) are all connected to an external power source after passing through the top cover (6); a fixing block (33) is provided at the bottom of the radial flow electrode plates (3); a fixing groove (34) provided inside the fixing block (33) is clamped with the bottom of the radial flow electrode plates (3); and the rear side wall of the fixing block (33) is fixedly connected to the inner wall of the reaction chamber (1).

8. The radial flow three-dimensional electrode electrolysis reactor for groundwater treatment according to claim 1, characterized in that: The particle electrode is an activated carbon carrier electrode particle loaded with Cu-Ce, and the preparation method of the activated carbon carrier electrode particle loaded with Cu-Ce is: S1. Pretreatment: Take the activated carbon powder and wash it with deionized water three times, immerse it completely in a hydrochloric acid solution with a molar concentration of 1 mol / L, ultrasonically treat it for 30 to 40 minutes, soak it for 1 to 2 hours, take it out, wash it with deionized water until the pH is neutral, dry it in an oven at 100 to 105°C for 1 to 2 hours, and take out the pretreated activated carbon powder for use; S2. Cu-Ce loading: Mix Cu(NO3)2 solution and Ce(NO3)2 solution with molar concentration of 40-50 mmol / L in a weight ratio of 1:1 to obtain an impregnation salt solution, and immerse the pretreated activated carbon powder in the impregnation salt solution for 20-24 hours, then place it in an oven at 100-105°C for drying for 1-2 hours, and then place it in a muffle furnace for calcination at 500-550°C for 2-3 hours. After taking it out, wash it three times with deionized water, place it in an oven at 100-105°C for drying for 1-2 hours, and obtain activated carbon carrier electrode particles loaded with Cu-Ce after cooling.

9. A radial flow three-dimensional electrode electrolysis reactor for groundwater treatment according to claim 8, characterized in that: In S1, the particle size of the activated carbon powder is less than 50 μm, the ultrasonic power is 80-100 Hz, and the weight ratio of the activated carbon powder to the hydrochloric acid is 1:1-2.

10. The method for constructing a radial flow three-dimensional electrode electrolysis reactor for groundwater treatment according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1. Sewage injection: The sewage to be treated is injected into the sewage pipe (2), and enters the reaction chamber (1) through the water outlet (21) on the sewage pipe (2). Then, the radial flow electrode plate (3) is energized so that the sewage flows out in a radial flow pattern from the center to the outside. The current density is adjusted to 70-100 A / m 2 ; S2. Particle electrode injection: adding particle electrodes into the reaction chamber (1) through the feeding pipe (12), with the added amount being 200-240 g / L of sewage; S3, circulation treatment: start the water pump (7) to extract the sewage that rises to the first outlet pipe (11), and re-inject it into the sewage pipe (2) through the return pipe (71), forming a continuous circulation treatment, the hydraulic retention time is 40 to 100 minutes, and the flow rate of the water pump (7) is 1 to 3L / h.

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