Three-dimensional electro-catalytic device for treating reverse osmosis concentrated water in water reuse

Abstract

The utility model discloses a kind of three-dimensional electrocatalytic devices for treating reverse osmosis concentrated water in reclaimed water reuse, it is related to water treatment technical field, including the pretreatment unit, three-dimensional electrocatalytic reaction unit and online cleaning assembly by pipeline communication, multiple parallel alternate equal interval matrix arrangement's anode plate, particle electrode assembly and cathode plate are fixedly arranged in three-dimensional electrocatalytic reaction unit;Reaction zone inner wall is equipped with liquid inlet and liquid discharge port, liquid inlet is communicated with pretreatment unit;Sedimentation zone bottom is equipped with blowdown port;The sidewall of shell is also equipped with circulating pipeline, circulating pump and flow valve are equipped on circulating pipeline, the inlet of circulating pipeline is communicated with the upper layer of reaction zone, the lower layer of reaction zone is communicated with the outlet of circulating pipeline.This application increases reaction area by three-dimensional electrode, supports internal circulation system to strengthen mass transfer, eliminates concentration polarization, combines online cleaning assembly to prevent scale, COD removal rate is ≥90%, it is applicable to depth treatment and reuse of reverse osmosis concentrated water in reclaimed water reuse system.

Description

Technical Field

[0001] This utility model relates to the field of water treatment equipment technology, and in particular to a three-dimensional electrocatalytic device for treating reverse osmosis concentrate by reclaiming wastewater. Background Technology

[0002] With increasing water scarcity and stringent environmental protection requirements, greywater reuse technology has been widely applied in industrial and domestic sectors. Reverse osmosis (RO) technology, a key component of greywater reuse, effectively removes impurities, salts, and microorganisms from water, but it also generates a certain amount of RO concentrate. RO concentrate is characterized by high salinity, high hardness, high organic matter content, and the presence of various heavy metal ions. Direct discharge without effective treatment not only wastes water resources but also causes serious pollution and damage to the ecological environment. Currently, treatment methods for RO concentrate mainly include physicochemical methods, biological methods, and membrane separation methods. Physicochemical methods, such as coagulation sedimentation, adsorption, and ion exchange, can remove some pollutants from the concentrate to a certain extent, but they suffer from low treatment efficiency, high reagent consumption, and the generation of large amounts of sludge, increasing subsequent treatment costs and environmental risks. When treating RO concentrate using biological methods, the high salinity and high content of recalcitrant organic matter inhibit the growth and metabolism of microorganisms, leading to unstable treatment results and difficulty in meeting increasingly stringent discharge standards. While membrane separation methods such as nanofiltration and reverse osmosis can achieve efficient separation and concentration of pollutants in concentrated water, they also suffer from problems such as severe membrane fouling, high operating costs, and large investments.

[0003] However, reverse osmosis concentrate contains high concentrations of salt and recalcitrant organic matter, and excessive calcium hardness easily leads to scaling in the equipment, posing a challenge in the wastewater reuse process. Traditional two-dimensional electrocatalytic devices suffer from limited reaction area, low mass transfer efficiency, and severe concentration polarization, resulting in a reaction efficiency of less than 60%. Furthermore, high calcium and magnesium ions easily form scale on the electrode surface, shortening the equipment's operating cycle to 30-60 days.

[0004] A search revealed a three-dimensional electrocatalytic reaction device disclosed in patent number "CN109607697A". This device includes a shell, with a gas-liquid lifting zone and a three-dimensional electrocatalytic reaction zone sequentially arranged along the direction from the bottom to the top of the shell. It also includes several hollow cathode columns and hollow anode columns nested together, with a catalyst placed in the gap between them. A water distribution device and a gas distribution device are both located in the gas-liquid lifting zone to distribute water and gas into the three-dimensional electrocatalytic reaction zone, and to fluidize the catalyst within the zone. However, while the aforementioned three-dimensional electrocatalytic scheme expands the reaction area through the catalyst (particle electrode), the catalyst (particle electrode) is prone to agglomeration and uneven distribution, and lacks a targeted anti-scaling design, making it difficult to adapt to the harsh operating conditions of reverse osmosis concentrate. Therefore, developing a novel electrocatalytic device for treating reverse osmosis concentrate in wastewater reuse is of significant practical importance and urgent need for improving the treatment efficiency of reverse osmosis concentrate, reducing treatment costs, realizing the recycling of water resources, and protecting the environment. Utility Model Content

[0005] This invention proposes a three-dimensional electrocatalytic device for treating reverse osmosis concentrate in wastewater reuse, which solves the problems of easy agglomeration and uneven distribution of particle electrodes in existing three-dimensional electrocatalytic devices, as well as the lack of targeted anti-scaling design.

[0006] A three-dimensional electrocatalytic device for treating reverse osmosis concentrate in wastewater reuse includes a pretreatment unit and a three-dimensional electrocatalytic reaction unit connected by pipelines. The three-dimensional electrocatalytic reaction unit includes a shell and a sealing cover. The sealing cover and the shell are sealed together to form a sealed cavity. The sealed cavity includes a reaction zone and a sedimentation zone. The reaction zone is located above the sedimentation zone. Multiple three-dimensional electrode assemblies are fixedly arranged in parallel and equally spaced intervals in the reaction zone. The three-dimensional electrode assemblies include an anode plate, a particle electrode assembly (37), and a cathode plate arranged in parallel and equally spaced intervals in sequence. The inner wall of the reaction zone is provided with an inlet and an outlet. The inlet is connected to the pretreatment unit. The bottom of the sedimentation zone is provided with a sewage outlet. The side wall of the shell is also provided with a circulation pipe. The circulation pipe is provided with a circulation pump and a flow valve. The inlet of the circulation pipe is connected to the upper layer of the reaction zone, and the outlet of the circulation pipe is connected to the lower layer of the reaction zone.

[0007] Preferably, the distance between the anode plate, the particle electrode assembly and the cathode plate is 8-10 mm.

[0008] Preferably, multiple insulating rods are horizontally arranged in the sealed cavity, and the two ends of the insulating rods are detachably fixed to the inner wall of the housing; the anode plate, cathode plate and particle electrode assembly are fixed on the insulating rods.

[0009] Preferably, the shell located in the sedimentation zone has an inverted conical shape, and an ultrasonic oscillator is provided on the inner wall of the sedimentation zone.

[0010] Preferably, the inner wall of the sealed cavity is provided with a polytetrafluoroethylene coating.

[0011] Preferably, the anode plate is a mesh titanium anode, the cathode plate is a porous titanium cathode, and the particle electrode assembly includes a mesh titanium alloy shell and activated carbon-supported titanium dioxide composite particle filler. Preferably, the particle size of the activated carbon-supported titanium dioxide composite particle filler is 3-5 mm.

[0012] Preferably, the pretreatment unit includes a quartz sand filter and a precision filter connected in sequence, and the outlet of the precision filter is connected to the inlet of the three-dimensional electrocatalytic reaction unit through a pipe.

[0013] Preferably, the particle size of the quartz sand filling in the quartz sand filter is 0.2-1.2 mm, and the particle size of the packing material in the precision filter is 5-8 μm.

[0014] Preferably, the system also includes an online cleaning unit, which includes a cleaning pump, a cleaning pipe, and a chemical storage tank. The inner side of the sealing cover is provided with a spray pipe, and the spray pipe is evenly provided with multiple spray nozzles. The chemical storage tank is connected to the spray pipe through the cleaning pump and the cleaning pipe.

[0015] The beneficial effects of this utility model are: 1. The three-dimensional electrocatalytic device of this utility model adopts a unique three-dimensional electrode arrangement structure design. The modular design of the particle electrode assembly facilitates maintenance and replacement, and can adapt to the treatment needs of concentrated water of different concentrations. The device is equipped with a circulation pipeline to enhance mass transfer, eliminate concentration polarization, and the pretreatment and online cleaning work together to clean the internal components of the equipment online, prevent scale buildup inside the equipment, and extend the continuous operation cycle of the equipment.

[0016] 2. The three-dimensional electrocatalytic device of this utility model utilizes parallel alternating and equally spaced anode and cathode main electrode plates and particle electrodes. Compared with the existing technology, it can increase the electrolysis reaction area, improve the removal rate of organic matter and heavy metal ions in reverse osmosis concentrate, achieve effective treatment of concentrate in a shorter time, improve the purity of concentrated water salt after treatment, and make the concentrated water salt recyclable. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a cross-sectional schematic diagram of the three-dimensional electrocatalytic reaction unit of this utility model; Figure 3 This is a schematic diagram of the internal structure of the three-dimensional electrocatalytic reaction unit of this utility model; Component names and serial numbers: 1. Quartz sand filter; 2. Precision filter; 3. Three-dimensional electrocatalytic reaction unit; 31. Shell; 32. Sealing cover; 33. Reaction zone; 34. Sedimentation zone; 35. Anode plate; 36. Cathode plate; 37. Particle electrode assembly; 38. Liquid inlet; 39. Liquid outlet; 310. Sewage outlet; 311. Circulation pipeline; 312. Circulation pump; 313. Flow valve; 314. Insulating rod; 315. Spray pipe; 4. Chemical storage tank; 5. Cleaning pump; 6. Cleaning pipeline. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can be arranged and designed in various different configurations. The following detailed description of the embodiments of this utility model provided in the accompanying drawings is not intended to limit the scope of the claimed utility model, but merely to illustrate selected embodiments of the utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the scope of protection of this utility model.

[0019] Unless otherwise defined, the technical or scientific terms used in this disclosure shall have the ordinary meaning as understood by a person skilled in the art to which this disclosure pertains. The words “comprising” or “including” or similar terms used in this disclosure mean that the element or object preceding the word covers the element or object listed after the word and its equivalents, without excluding other elements or objects.

[0020] like Figures 1-3As shown, a three-dimensional electrocatalytic device for treating reverse osmosis concentrate in wastewater reuse includes a pretreatment unit and a three-dimensional electrocatalytic reaction unit 3 connected by pipelines. The three-dimensional electrocatalytic reaction unit 3 includes a shell 31 and a sealing cover 32. The sealing cover 32 and the shell 31 are sealed together to form a sealed cavity. The sealed cavity includes a reaction zone 33 and a sedimentation zone 34. The reaction zone 33 is located above the sedimentation zone 34. A plurality of parallel three-dimensional electrode assemblies are fixedly arranged in the reaction zone 33. The three-dimensional electrode assembly includes sequentially parallel three-dimensional electrode assemblies. The reaction zone 33 includes an anode plate 35, a particle electrode assembly 37, and a cathode plate 36. The inner wall of the reaction zone 33 is provided with an inlet 38 and an outlet 39, the inlet 38 being connected to a pretreatment unit. The sedimentation zone 34 has a drain outlet 310 at its bottom, with a shut-off valve at the drain outlet 310. The side wall of the housing 31 is also provided with a circulation pipe 311, which is equipped with a circulation pump 312 and a flow valve 313. The inlet of the circulation pipe 311 connects to the upper layer of the reaction zone 33, and the outlet of the circulation pipe 311 connects to the lower layer of the reaction zone 33. This device increases the reaction area through three-dimensional electrodes and is equipped with a circulation pipe 311, whose circulation flow rate is 2-3 times that of the inlet 38, which can enhance mass transfer, eliminate concentration polarization, and achieve a COD removal rate of ≥90%. Overall, this application can increase the electrolysis reaction area by 2-3 times compared with traditional devices, and improve the removal rate of organic matter and heavy metal ions in reverse osmosis concentrate by 30%-50% compared with traditional treatment methods. It can achieve effective treatment of concentrate in a shorter time, and the salt purity of the treated concentrate can reach 99.5%. It is suitable for the deep treatment and reuse of reverse osmosis concentrate in the reclaimed water system.

[0021] Specifically, the distance between the anode plate 35, the particle electrode assembly and the cathode plate 36 is 8-10 mm, and the anode plate 35 and the cathode plate 36 are electrically connected to an adjustable DC power supply.

[0022] Specifically, multiple insulating rods 314 are horizontally arranged in the sealed cavity, and both ends of the insulating rods 314 are detachably fixed to the inner wall of the housing 31; the anode plate 35, cathode plate 36, and particle electrode assembly are fixed on the insulating rods 314. This facilitates the maintenance and replacement of the anode plate 35, cathode plate 36, and particle electrode assembly.

[0023] Specifically, the shell 31 located in the sedimentation zone 34 has an inverted cone shape, which makes the sludge discharge smoother and less prone to clogging. The inner wall of the sedimentation zone 34 is equipped with an ultrasonic oscillator for oscillation to assist in sludge discharge.

[0024] Specifically, the inner wall of the sealed cavity is coated with polytetrafluoroethylene to effectively prevent the shell 31 from becoming conductive and corroded.

[0025] Specifically, the anode plate 35 is a mesh titanium anode, the cathode plate 36 is a porous titanium cathode, and the particle electrode assembly 37 includes a mesh titanium alloy shell and activated carbon-supported titanium dioxide composite particle filler, the particle size of which is 3-5 mm.

[0026] Specifically, the pretreatment unit includes a quartz sand filter 1 and a precision filter 2 connected in sequence. The outlet of the precision filter 2 is connected to the inlet 38 of the three-dimensional electrocatalytic reaction unit 3 via a pipe. The quartz sand filled in the quartz sand filter 1 has a particle size of 0.2-1.2 mm, and the filler particle size in the precision filter 2 is 5 μm. This is used to filter and remove suspended solids and colloidal particles from the wastewater, reducing the risk of subsequent electrode contamination. It is worth noting that both the quartz sand filter 1 and the precision filter 2 are commercially available filters capable of achieving the same effect; they are existing technologies, and their specific structural details are not elaborated in this application.

[0027] Specifically, it also includes an online cleaning unit, which includes a cleaning pump 5, a cleaning pipe 6, and a chemical storage tank 4. The inner side of the sealing cover 32 is provided with a spray pipe 315, and the spray pipe 315 is evenly provided with multiple spray nozzles. The chemical storage tank 4 is connected to the spray pipe 315 through the cleaning pump 5 and the cleaning pipe 6. By regularly spraying the chemical agent to clean the online cleaning components, it is possible to effectively prevent scale buildup and blockage of internal components, thus extending the continuous operation cycle of the equipment to more than 120 days. In this embodiment, the chemical agent is a commercially available conventional compound alkaline cleaning agent: a mixture of 1-2% NaOH + 0.1-0.5% special low-foaming surfactant. Alternatively, any other commercially available cleaning agent that can achieve the same effect can be used.

[0028] Working process and principle: Wastewater first undergoes dual filtration through a quartz sand filter 1 and a precision filter 2 to remove suspended solids and colloidal particles. The filtered wastewater then enters the three-dimensional electrocatalytic reaction unit 3 through the inlet, where it is electrolyzed by the anode plate 35 and the cathode plate 36. The particle electrode assembly 37 assists in enhancing the electrolysis reaction, oxidizing, decomposing, or reducing organic matter in the wastewater to precipitate it into sludge. Simultaneously with the electrolysis reaction, the circulation pump 312 is activated, driving the wastewater to circulate internally, eliminating concentration polarization within the three-dimensional electrocatalytic reaction unit 3, enhancing mass transfer, and increasing electrolysis efficiency. After electrolysis, the supernatant is discharged through the drain port 39. After drainage, the shut-off valve at the sewage outlet 310 is opened, and the ultrasonic oscillator is activated to discharge the sludge and other mixture precipitated in the sedimentation zone 34 through the sewage outlet 310. After drainage and sewage discharge, the cleaning pump 5 is activated to evenly spray cleaning agents into the internal components of the three-dimensional electrocatalytic reaction unit 3 through the spray pipe 315 for cleaning.

[0029] The above description is a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the technical scope disclosed in this utility model, based on the technical solution and concept of this utility model, should be covered within the protection scope of the claims of this utility model.

Claims

1. A three-dimensional electrocatalytic device for treating reverse osmosis concentrate in wastewater reuse, comprising a pretreatment unit and a three-dimensional electrocatalytic reaction unit (3) connected by pipelines, characterized in that: The three-dimensional electrocatalytic reaction unit (3) includes a shell (31) and a sealing cap (32). The sealing cap (32) and the shell (31) are closed to form a sealed cavity. The sealed cavity includes a reaction zone (33) and a precipitation zone (34). The reaction zone (33) is located above the precipitation zone (34). Multiple three-dimensional electrode assemblies are fixedly arranged in parallel and equally spaced positions in the reaction zone (33). The three-dimensional electrode assembly includes an anode plate (35), a particle electrode assembly (37), and a cathode plate (36) arranged in parallel and equally spaced positions in sequence. The inner wall of the reaction zone (33) is provided with an inlet (38) and a outlet (39), and the inlet (38) is connected to the pretreatment unit; the bottom of the sedimentation zone (34) is provided with a drain outlet (310); the side wall of the shell (31) is also provided with a circulation pipe (311), and the circulation pipe (311) is provided with a circulation pump (312) and a flow valve (313). The inlet of the circulation pipe (311) is connected to the upper layer of the reaction zone (33), and the outlet of the circulation pipe (311) is connected to the lower layer of the reaction zone (33).

2. The three-dimensional electrocatalytic device for treating reverse osmosis concentrate in wastewater reuse according to claim 1, characterized in that: The distance between the anode plate (35), the particle electrode assembly (37) and the cathode plate (36) is 8-10 mm.

3. The three-dimensional electrocatalytic device for treating reverse osmosis concentrate in wastewater reuse according to claim 1, characterized in that: Multiple insulating rods (314) are horizontally arranged in the sealed cavity. The two ends of the insulating rods (314) are detachably fixed to the inner wall of the housing (31). The anode plate (35), cathode plate (36) and particle electrode assembly are fixed on the insulating rods (314).

4. The three-dimensional electrocatalytic device for treating reverse osmosis concentrate in wastewater reuse according to claim 1, characterized in that: The shell (31) located in the sedimentation zone (34) has an inverted cone shape, and the inner wall of the sedimentation zone (34) is provided with an ultrasonic oscillator.

5. The three-dimensional electrocatalytic device for treating reverse osmosis concentrate in wastewater reuse according to claim 1, characterized in that: The inner wall of the sealed cavity is coated with polytetrafluoroethylene.

6. The three-dimensional electrocatalytic device for treating reverse osmosis concentrate in wastewater reuse according to claim 1, characterized in that: The anode plate (35) is a mesh titanium anode, the cathode plate (36) is a porous titanium cathode, and the particle electrode assembly (37) includes a mesh titanium alloy shell and activated carbon-supported titanium dioxide composite particle filler filled in the shell.

7. The three-dimensional electrocatalytic device for treating reverse osmosis concentrate in wastewater reuse according to claim 6, characterized in that: The particle size of the activated carbon-supported titanium dioxide composite particle filler is 3-5 mm.

8. A three-dimensional electrocatalytic device for treating reverse osmosis concentrate in wastewater reuse according to any one of claims 1-7, characterized in that: The pretreatment unit includes a quartz sand filter (1) and a precision filter (2) connected in sequence. The outlet of the precision filter (2) is connected to the inlet (38) of the three-dimensional electrocatalytic reaction unit (3) through a pipe.

9. A three-dimensional electrocatalytic device for treating reverse osmosis concentrate in wastewater reuse according to claim 8, characterized in that: The quartz sand filter (1) is filled with quartz sand with a particle size of 0.2-1.2 mm, and the precision filter (2) is filled with filler with a particle size of 5-8 μm.

10. A three-dimensional electrocatalytic device for treating reverse osmosis concentrate in water reuse according to any one of claims 1-7, characterized in that: It also includes an online cleaning unit, which includes a cleaning pump (5), a cleaning pipe (6) and a chemical storage tank (4). The inner side of the sealing cover (32) is provided with a spray pipe (315), and multiple spray nozzles are evenly provided on the spray pipe (315). The chemical storage tank (4) is connected to the spray pipe (315) through the cleaning pump (5) and the cleaning pipe (6).

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