Water quality advanced treatment device and water quality advanced treatment method

Abstract

The present application relates to a kind of water quality advanced treatment device, the processing device is equipped with the reactor shell for containing water, electrode is equipped in the reactor shell for electrochemical reaction, the reactor shell is also equipped with several suspendable graphite ball, the reactor shell is equipped with reflux pump, for the reflux circulation of water in the reactor shell, the bottom of the reactor shell is equipped with filter isolation net, baffle is located above the filter isolation net, the inlet of circulating pipe is located below the filter isolation net.The present application also relates to a kind of water quality advanced treatment method, the processing method is carried out water quality advanced treatment using the above processing device, graphite ball impacts electrode charging, and forms graphite ball electric field in the whole reaction region.The present application can reduce the cost of device, improve reaction capacity.

Description

Technical Field

[0001] This invention relates to a water deep treatment device and a water deep treatment method. Background Technology

[0002] Electrochemical (electrocatalytic) wastewater treatment removes pollutants or impurities from water by regulating the directional transfer of electrons under an applied electric field, causing specific physical and chemical reactions through these reactions. The physical processes mainly include adsorption, flocculation, and membrane separation, while the chemical processes include direct and indirect electrolysis. Direct electrolysis involves the direct oxidation or reduction of pollutants at the electrodes, while indirect electrolysis utilizes the strong oxidizing or reducing intermediates produced by the electrochemical reaction to degrade or transform pollutants. Specific applications include: Electrochemical oxidation-reduction: Oxidation and reduction reactions occur at different potentials in an electrolytic cell, with oxidation at the anode and reduction at the cathode, typically reducing pollutants to water or other relatively stable substances; Electrochemical conversion and combustion: Direct electrooxidation directly converts pollutants in wastewater into harmless substances, while electrochemical combustion converts pollutants into carbon dioxide and water; Electrochemical resource recovery technology: Valuable substances, such as chlorides and sulfides, are extracted from wastewater using electrolyte reactions, thereby gaining economic value and conserving resources. The advantage of electrochemical wastewater treatment lies in its lack of secondary pollution, hence it is considered a clean process. Compared to traditional physical, biological, and chemical treatment methods, electrochemical treatment is more efficient and environmentally friendly. For example, it can be used at the end of a wastewater treatment system, reducing phosphorus in wastewater to solid precipitates through electrochemical reactions, achieving deep phosphorus removal. The hydroxyl groups generated during electrochemical water electrolysis oxidize pollutants in the water into inorganic substances, further reducing COD. It can also be used at the front end of a wastewater treatment system for pretreatment, utilizing the electrochemical oxidation-reduction capabilities to degrade recalcitrant organic matter in the water, converting it into smaller molecules that are easier for subsequent biological systems to absorb. Simultaneously, iron is released at the anode during electrooxidation. Iron not only helps promote the enrichment of anammox and iron-reducing bacteria, increasing the abundance of functional genes and the activity of related enzymes, but also improves sludge performance and enhances the stability of anammox systems by influencing sludge concentration, heme C content, extracellular polymer content, and granulation degree. Existing electrochemical treatment equipment mainly consists of several parallel electrode plates installed in a tank / pool, alternately connected to the positive and negative terminals of a power source to create an electric field between the positive and negative electrode plates. For example, Chinese patent document CN115650393A discloses an electrochemical phosphorus removal device and its phosphorus removal method, including a phosphorus removal unit. The phosphorus removal unit includes a phosphorus removal tank and a drainage tank. The upper end of the phosphorus removal tank is connected to the upper end of the drainage tank, and a support frame is installed inside the phosphorus removal tank. Multiple electrode plates are installed on the support frame at intervals. By using electrode plates for phosphorus removal, no reagents (physical or chemical) need to be added during the phosphorus removal process of the wastewater.Chinese patent document CN111018201A discloses an electrochemical phosphorus removal device and method. The electrochemical phosphorus removal device sequentially comprises a reaction zone and an electrolysis zone. The reaction zone includes two-stage coagulation reaction tanks separated by baffles. The electrolysis zone includes a receiving tank, a water distribution zone, electrode plates, and induction electrode plates. An overflow tank is provided at the top of the receiving tank. Because the area covered by the electrode plates is limited, electrochemical reactions are difficult to occur outside the electrode plate pairs, affecting the reaction capacity and purification level. Expanding the reaction area requires more electrode plates, leading to a significant increase in cost and operating expenses. Summary of the Invention

[0003] To overcome the aforementioned deficiencies of the prior art, the present invention provides an electrochemical / electrocatalytic water treatment device and a water treatment method using the device, so as to reduce device cost and improve reaction capacity.

[0004] The technical solution of the present invention is: a water quality deep treatment device, which is provided with a reactor shell for containing water, an electrode for electrochemical reaction is provided inside the reactor shell, and a number of graphite balls are also provided.

[0005] Furthermore, the graphite spheres are suspendable graphite spheres.

[0006] Preferably, the graphite spheres are hollow graphite spheres. The hollow design reduces the weight of the graphite spheres, thus enabling them to suspend in water.

[0007] Preferably, the electrode is an electrocatalytic reaction module composed of positive and negative electrode plates, with one positive and one negative electrode plate in the same electrocatalytic reaction module, having equal areas and being parallel to each other.

[0008] Preferably, the positive and negative electrodes in the same electrocatalytic reaction module can be fixedly connected as one unit by an electrode fixing plate and a pad. The electrode fixing plate is provided with two hanging strips for hanging, and the electrocatalytic reaction module is hung on the bracket inside the reactor shell by the hanging strips.

[0009] Preferably, the reactor shell is equipped with a water level sensor for sensing the water level height or the water level reaching a certain position, so as to perform corresponding control operations.

[0010] Preferably, the reactor shell is equipped with a reflux pump for reflux circulation of water within the reactor shell, and the reflux circulation enables mixing and agitation of the water within the reactor shell.

[0011] Preferably, the reactor shell is provided with an inlet pipe and a circulation pipe, and a deflector plate is provided at the lower part of the reactor shell. The inlet pipe extends vertically into the reactor shell from the top and extends above the deflector plate. The distance between its outlet and the deflector plate should ensure that the effluent can be effectively guided upward and outward by the deflector plate. The circulation pump is connected in series with the circulation pipe. The inlet of the circulation pipe is located below the deflector plate, and the outlet of the circulation pipe is connected to the inlet pipe.

[0012] Preferably, a filter screen is provided at the bottom of the reactor shell to isolate graphite balls in the water, the baffle plate is located above the filter screen, and the inlet of the circulation pipe is located below the filter screen.

[0013] A method for advanced water treatment is disclosed in this invention. The method employs any of the advanced water treatment devices disclosed herein, using an intermittent operating mode. Water to be treated is introduced into the reactor shell. Once a set height is reached, the water intake is stopped, the electrode power supply is switched on, and hydraulic agitation is implemented. This causes graphite spheres inside the reactor shell to move with the water flow. During collisions with the electrodes, these spheres acquire electrical charges, which in turn charge the graphite spheres, forming a corresponding electric field throughout the reaction area. Treatment is terminated after the set treatment time or desired effect is achieved, and the treated water is then drawn out, completing one treatment cycle.

[0014] The beneficial effects of this invention are as follows: Due to the inclusion of charged and suspendable graphite spheres, these spheres acquire charge upon impact with the electrode plates. Since the graphite spheres are distributed throughout the water within the reactor shell, a certain intensity of electric field (weak relative to the electric field between the positive and negative electrode plates) is generated in the entire reaction area within the reactor shell. This weak electric field, in synergy with the strong electric field between the electrode plates, participates in / enhances the electrocatalytic / electrochemical reactions in all reaction areas and helps to achieve balanced reactions in all parts. Simultaneously, due to the synergistic effect of the weak electric field throughout the entire area, the strong electric field between the electrode plates does not need to be excessively strong, thus avoiding excessive reactions in localized areas. Therefore, a large power supply is not required, which also helps to reduce the consumption of electrode materials and electricity, and helps to avoid overloading subsequent processing equipment (e.g., filtration devices) due to excessive precipitation of electrode metal ions. Field experiments show that compared to the same processing equipment and operating mode without graphite spheres, the inclusion of graphite spheres significantly improves the reaction effect, shortens the reaction time, and allows for the use of smaller electrode currents. Attached Figure Description

[0015] Figure 1 This is a schematic diagram illustrating the structure and working principle of the advanced water treatment device of the present invention; Figure 2 This is a schematic diagram illustrating one usage method of the advanced water treatment device of the present invention; Figure 3 This is a schematic diagram (side view) of the electrocatalytic reaction module of the present invention. Figure 4 This is a schematic diagram (front view) of the electrocatalytic reaction module and its suspension method of the present invention. Detailed Implementation

[0016] See Figures 1-4 The advanced water treatment device of this invention can be improved based on existing electrochemical wastewater treatment devices. According to actual needs, several sets of positive and negative electrode plates are arranged inside the reactor shell 10. Simultaneously, an appropriate amount of graphite spheres 20 are loaded. The graphite spheres have a hollow structure so that they can be suspended in the flowing water inside the reactor shell during the reaction process. The density of the graphite spheres (the density when evenly distributed in water) should ensure the formation of an effective graphite sphere electric field (derived from the weak electric field of the charged graphite spheres), and should not affect the water flow and water treatment capacity due to excessive graphite sphere density. The optimal amount of graphite spheres can be determined experimentally. The apparent density of the hollow graphite spheres should be the same as or approximately the same as the density of water, so that at least in the presence of water flow, the graphite spheres can be suspended in the water and move with the water.

[0017] The size of graphite spheres can be around 1 cm (diameter or equivalent diameter). Depending on the actual needs and the preparation process of the graphite spheres, other sizes of graphite spheres can also be used.

[0018] Graphite spheres contain graphite and are capable of carrying an electrical charge. Depending on the specific needs, they can be made entirely of graphite or partially of graphite.

[0019] The electrocatalytic reaction module 30 installed inside the reactor shell can be one or more, for example, two, depending on the size of the space / reaction area inside the reactor shell and the reaction requirements.

[0020] The reactor shell can be made of fiberglass to achieve insulation and reduce costs.

[0021] The reactor shell can be a cylindrical tank / cylinder shape, or any other suitable shape.

[0022] The matching positive and negative electrodes 31 can be fixedly connected as a whole through the electrode fixing plate 32 and the pad 33 to form an integrated electrocatalytic reaction module for easy installation and use.

[0023] The electrode fixing plate is plate-shaped and has electrode mounting holes (rectangular through holes conforming to the shape of the electrodes) for passing through the positive and negative electrode plates. The middle part of the positive and negative electrode plates passes through the corresponding electrode mounting holes and is fixedly connected to the electrode fixing plate (any suitable form of fastener or snap-fit / limiting structure can be used for fixing).

[0024] The electrode plate fixing plate is provided with two hanging strips 36 for hanging, and the electrocatalytic reaction module is suspended on the bracket 38 inside the reactor shell by the hanging strips. The hanging strips can be set at / connected to both ends of the electrode plate fixing plate, and the top of the hanging strip is provided with a hook (a hook-shaped structure for suspension / hanging) 37, so as to be suspended on the bracket by the hook.

[0025] Two parallel support strips (e.g., angle steel) can be installed on the bracket to suspend the electrocatalytic reaction module. Hanging holes for hooks are provided on the support strips (conformable to the hook tip to allow insertion while preventing significant wobbling; the position of the hanging holes on the support strips is adapted to the size of the hooks; when the hook tip is inserted into the hanging hole, the side of the hanging strip is in contact with the side of the support strip). During assembly, the two hanging strips of the reaction module are placed downwards between the two support strips, so that the hooks (hooks) at the top of the two hanging strips are precisely inserted into their respective hanging holes, thereby achieving suspension and positioning. Using strips ensures that the hanging strips and support strips are in planar contact, guaranteeing stability.

[0026] The hanging strip and the electrode plate fixing plate can also be connected by a hook. For example, a lower hook is installed at the lower end of the hanging strip, with the hook end facing upwards. Fixing plate hanging holes matching the lower hook are opened at both ends of the electrode plate fixing plate. The hook end of the lower hook is inserted into the fixing plate hanging hole from the lower end of the fixing plate hanging hole, thereby realizing the connection / hanging of the hanging strip to the electrode plate fixing plate.

[0027] A pad 33, which also functions as a lifting lug, is provided between the tops of the positive and negative electrode plates to support the proper spacing between them. The pad is fixedly connected to the top of the positive and negative electrode plates. Through the coordinated fixing action of the pad and the electrode plate fixing plate, the positive and negative electrodes can be more firmly fixed into one unit. The upper part of the pad protrudes from the top of the positive and negative electrode plates and is provided with a through hole 34 to form a lifting lug for easy hoisting.

[0028] The reactor shell is equipped with a water level sensor for sensing water level height or sensing when the water level reaches a set height, so as to perform corresponding control operations.

[0029] The inlet pipe 11 of the reactor extends vertically into the reactor shell from the top and extends above the baffle plate (or water distributor) 16. The distance between its outlet and the baffle plate should ensure that the effluent can be effectively guided upward and outward by the baffle plate. The circulation pump 25 is connected in series with the circulation pipe 26. The inlet of the circulation pipe is located below the baffle plate (it can extend directly to the baffle plate inside the reactor shell, or it can be connected to the reactor shell wall located vertically below the baffle plate). The outlet of the circulation pipe is connected to the inlet pipe.

[0030] The deflector plate is a curved surface with an upward curve at the periphery, and its axis of rotation coincides with the axis of the reactor shell. The water inlet pipe inside the reactor shell extends vertically and is vertical, and its axis also coincides with the axis of the reactor shell. As a result, the water flowing out of the water inlet pipe outlet is evenly distributed to all sides by the action of the deflector plate.

[0031] The bottom of the reactor shell (the area near the bottom of the reactor shell) is equipped with a filter screen 22 to isolate graphite balls in the water. If necessary, it can also isolate other impurities. The size of the mesh can be set according to actual needs.

[0032] The baffle plate is located above the filter screen, and the inlet of the circulation pipe is located below the filter screen, so that the water entering the circulation pipe does not contain graphite balls.

[0033] The reactor's outlet pipe 12 can be connected to the filter device 40's inlet pipe 41, through which water is introduced into the filter device. The filter device is equipped with filter materials / filter layers 42 such as quartz sand to remove impurities from the water.

[0034] The reactor shell can be a tank, and the filtration device can also be tank-shaped.

[0035] The required pipelines can be configured according to actual needs, and pumps, valves 51 and various required testing instruments can be installed. For example, safety valves 52 can be installed on the top of the closed reactor shell (e.g., tank) and the top of the sealed filter device. The reaction device and the filter device can be configured with gas and water backwashing pipelines 55 and sewage discharge pipelines 56, etc.

[0036] The basic working principle of this electrocatalytic reactor (treatment device) is as follows: It operates intermittently, introducing water to be treated into the reactor shell. Once the set height is reached, the water intake is stopped, the electrode power supply is switched on, and hydraulic agitation (or stirring; when using a circulating pump for hydraulic agitation, the circulating pump is turned on) is implemented. This causes the graphite spheres inside the reactor shell to move with the water flow, gaining charge from the electrodes during collisions. This charge on the graphite spheres then forms a corresponding electric field throughout the entire reaction area (the area inside the reactor shell containing water). Once the set treatment time or treatment effect is achieved, the treatment is terminated (the electrode power supply is switched off, and the hydraulic agitation is stopped). The treated water is then drawn out, completing one treatment cycle.

[0037] The system employs an intermittent flow / intermittent operation, with each batch of reactions carried out in a batch, each reaction lasting 20 minutes or other suitable time, and the process is repeated continuously.

[0038] The area containing the anode and cathode electrodes is the main reaction zone. Graphite spheres loaded inside the tank (or other reactor shell) rotate and flow with the water flow within the tank. These spheres collide with the positive and negative electrodes, acquiring / carrying a certain amount of charge, which is then released as the water flows. While electrocatalysis occurs in the main reaction zone, other areas undergo micro-electrolysis reactions following the graphite spheres, forming a large source cell that fills the entire fiberglass tank area. This facilitates the formation of a stable reactor.

[0039] This device can be used for advanced water treatment, such as phosphorus removal from biochemically treated water, or further purification of total phosphorus, suspended solids, and chemical oxygen demand, and can be used as pretreatment in wastewater treatment systems.

[0040] The operation is as follows: Water to be treated is injected into the reaction chamber (the space inside the reactor shell) through the inlet pipe. A level sensor, detecting when the set liquid level is reached, outputs a signal upon contact with the water. The control device then shuts off the inlet, connects the electrode power supply, and initiates the electrocatalytic / electrochemical reaction. Simultaneously, a circulation pump draws liquid from below the filter screen inside the shell. The circulating liquid flows back through the circulation pipe and inlet pipe to above the filter screen inside the shell, towards the distributor (baffle plate). Guided by the distributor, it flows obliquely upwards and outwards, blowing up the graphite spheres inside the reactor and circulating them within the container. Upon collision with the electrodes, the graphite spheres accept the charge from the electrodes, carrying the charge and transferring it to other graphite spheres in contact with them. This charge then enters the water and participates in the water reaction. After the reaction time is reached, the outlet electric valve starts to discharge water, closing after emptying. The inlet electric valve opens to fill with water, closing after full. The reactor then continues its cycle. The typical reactor reaction time is 5-60 minutes.

[0041] In synergy with the strong current region of the main electrode reaction area, the weak electric field region formed by the presence of charged graphite particles in the region far from the electrode also participates in the electrocatalytic reaction. Furthermore, because of the presence of the graphite electric field, the strong electric field electrode region does not need to continuously increase the power supply, thus avoiding excessive reaction. At the same time, it also saves on the loss of electrical energy and electrode (sacrificial electrode), reducing the consumption of electrode materials and electricity, and avoiding the overload operation of downstream filtration devices and other equipment caused by excessive metal ion precipitation.

[0042] The system operates intermittently, and the purification time for each batch of water can be adjusted according to changes in water quality.

[0043] By using a circulating pump, the flow of water within the tank can be increased, increasing the chances of contact between the electrodes. The water force is used to propel the graphite spheres, causing charge transfer through collisions with the electrodes, thus making the electrocatalytic reaction more complete.

[0044] Automatic air and water washing can be performed inside the reactor (shell). The wastewater generated from the washing can be discharged to the next stage for centralized treatment, such as to a sedimentation tank. The interior of the filtration device (which can be called a sand filter chamber) can also be backwashed as needed, for example, by performing air and water backwashing daily. The washing wastewater can also be discharged to a sedimentation tank.

[0045] The supernatant from the sedimentation tank can be returned to the reactor and purified together with the influent through electrocatalytic purification.

[0046] Unless otherwise specified, the preferred and optional technical means disclosed in this invention can be arbitrarily combined to form several different specific embodiments when one preferred or optional technical means is a further limitation of another technical means.

Claims

1. A water treatment device comprising a reactor shell for containing water, wherein electrodes for electrochemical reactions are disposed within the reactor shell, characterized in that... The reactor shell also contains several hollow graphite spheres with an apparent density similar to that of water. The density of the graphite spheres is designed to ensure the formation of an effective electric field without negatively impacting water flow or treatment capacity due to excessive density. The goal is to generate a sufficiently strong electric field throughout the reaction zone by charging the graphite spheres. This electric field, in conjunction with the strong electric field between the electrode plates, participates in and enhances the electrocatalytic / electrochemical reactions in the entire reaction zone. The reactor's inlet pipe extends vertically from the top of the reactor shell, reaching the return deflector plate. Above, the distance between the outlet and the return deflector plate should ensure that the effluent can be effectively guided upward and outward by the return deflector plate. The return deflector plate is a curved surface with an upward-curving periphery, and its axis of rotation coincides with the axis of the reactor shell. A circulation pump is connected in series with the circulation pipe. The inlet of the circulation pipe is located below the return deflector plate, and the outlet of the circulation pipe is connected to the inlet pipe. Through circulation and return, the power of the circulation pump increases the flow of water in the tank, increases the contact opportunity of the electrode reaction, and uses water power to drive the graphite balls to flow, generating charge transfer through collision with the electrodes.

2. The water deep treatment device as described in claim 1, characterized in that... The electrode is an electrocatalytic reaction module composed of positive and negative electrode plates. There is one positive and one negative electrode plate in the same electrocatalytic reaction module, with equal area and parallel to each other.

3. The water deep treatment device as described in claim 2, characterized in that... The positive and negative electrodes in the same electrocatalytic reaction module are fixedly connected as one unit by an electrode fixing plate and a pad. The electrode fixing plate is provided with two hanging strips for hanging, and the electrocatalytic reaction module is suspended on the bracket inside the reactor shell by the hanging strips.

4. The water deep treatment device according to any one of claims 1-3, characterized in that... The reactor shell is equipped with a water level sensor for sensing water level height or water level arrival.

5. The water deep treatment device according to any one of claims 1-3, characterized in that... The bottom of the reactor shell is equipped with a filter screen, the baffle plate is located above the filter screen, and the inlet of the circulation pipe is located below the filter screen.

6. A method for advanced water treatment, characterized in that... The water quality deep treatment device according to any one of claims 1-5 is used for deep water treatment. It adopts an intermittent working mode, introduces the water to be treated into the reactor shell, stops the water intake after reaching the set height, connects the electrode power supply, and implements hydraulic agitation, so that the graphite balls in the water move with the water flow. During the collision with the electrode, they gain charge from the electrode, and then form a corresponding electric field in the entire reaction area through the charge of the graphite balls. When the set treatment time or treatment effect is reached, the treatment is terminated, and the treated water is drawn out to complete one treatment cycle.

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