An electrochemical integrated device for phosphorus removal from sewage

Abstract

The utility model discloses an electrochemistry integration device for sewage phosphorus removal. The electrochemistry integration device for sewage phosphorus removal comprises: a water inlet steady flow unit, an electrochemical reaction cavity, a gas-liquid separation system and a water outlet monitoring and reflux unit; the water inlet steady flow unit is used for stabilizing the flow and water quality of raw water, and comprises an equalizing tank, a rough filtration unit, a valve group, a water inlet online monitoring section, a flowmeter and a metering pump; the inlet of the electrochemical reaction cavity is communicated with the outlet of the water inlet steady flow unit, and the electrochemical reaction cavity is provided with an inlet manifold, a flow guide grid, a multi-channel electrode stack, a main flow channel located at the bottom of the cavity for collecting outlet water and an outlet short pipe. The electrochemistry integration device for sewage phosphorus removal provided by the utility model solves the problems of unstable phosphorus removal effect and poor operation reliability of the existing electrochemical phosphorus removal device caused by uneven water distribution, air blockage, lack of closed-loop control and maintenance impact.

Description

Technical Field

[0001] This utility model relates to the field of wastewater treatment technology, and in particular to an electrochemical integrated device for phosphorus removal from wastewater. Background Technology

[0002] Phosphorus is a key pollutant causing eutrophication of water bodies, and the advanced treatment of phosphorus-containing wastewater is a major demand in the environmental protection field. Traditional chemical precipitation methods for phosphorus removal consume large amounts of phosphorus removal agents, produce a large amount of sludge, and the quality of the effluent is easily affected by fluctuations in the raw water. Biological phosphorus removal methods have problems such as slow start-up, complex operation and control, and strong dependence on temperature and carbon source.

[0003] Electrochemical methods (including electroadsorption, electrocatalysis, and electrocoagulation) are an emerging phosphorus removal technology with advantages such as rapid start-up and shutdown, environmental friendliness, and small footprint. However, during engineering scale-up and application, this technology has revealed several common technical challenges: 1. Fluctuations and uneven distribution of influent: Fluctuations in water quality and quantity can lead to uneven loads in the flow channels within the electrode stack, resulting in "short-circuit flow" and "overload in the same area", which reduces the overall reaction efficiency and electrode life.

[0004] 2. Gas trapping and signal interference during the electrochemical reaction: If the gas generated during the electrochemical reaction cannot be discharged in time, it will accumulate at the top of the cavity, causing "gas blockage", resulting in uneven current distribution and severe fluctuations in online monitoring signals such as pH and EC, affecting control stability.

[0005] 3. Lack of intelligent closed-loop control: Most existing devices lack a real-time judgment and feedback mechanism for effluent water quality. When the total phosphorus in the effluent does not meet the standard, manual intervention is usually required, and automatic recirculation and reprocessing cannot be achieved, resulting in unpredictable operating results.

[0006] 4. Impact risks during maintenance: When backflushing or chemical cleaning, the system may face transient pressure shocks and backflow risks. Without dedicated process design and valve group protection, it may easily cause equipment damage or secondary pollution.

[0007] Therefore, it is necessary to provide an electrochemical integrated device for phosphorus removal from wastewater to solve the above-mentioned technical problems. Utility Model Content

[0008] In view of the above situation and to overcome the defects of the existing technology, this utility model provides an electrochemical integrated device for phosphorus removal in wastewater, which can solve the problems of unstable phosphorus removal effect and poor operational reliability caused by uneven water distribution, air blockage, lack of closed-loop control and maintenance impact in existing electrochemical phosphorus removal devices.

[0009] To achieve the above objectives, the technical solution adopted by this utility model is as follows: An integrated electrochemical device for phosphorus removal in wastewater includes: an influent flow stabilization unit, an electrochemical reaction chamber, a gas-liquid separation system, and an effluent monitoring and reflux unit. The influent flow stabilization unit stabilizes the flow rate and water quality of the raw water and includes an equalization tank, a coarse filter unit, valve groups, an online influent monitoring section, a flow meter, and a metering pump. The inlet of the electrochemical reaction chamber is connected to the outlet of the influent flow stabilization unit. The electrochemical reaction chamber is equipped with an inlet manifold, a flow guide grid, a multi-channel electrode stack, a main flow channel at the bottom of the chamber for collecting effluent, and an outlet short pipe. The anode area of ​​the multi-channel electrode stack is equipped with phosphorus removal active materials. The gas-liquid separation system includes a ring pipe located at the top of the electrochemical reaction chamber, an automatic exhaust valve connected to the highest point of the ring pipe, and a gas-liquid separation tank, used to separate and discharge the gas generated during the reaction process; the effluent monitoring and reflux unit includes an online effluent monitoring section, a three-way switching valve, a check valve, and a reflux pump. The inlet and outlet short pipes of the online effluent monitoring section are connected, and the common port of the three-way switching valve is connected to the outlet of the online effluent monitoring section. Its first outlet leads to the product water branch, and the second outlet, after passing through the check valve and the reflux pump, is connected back to the upstream of the metering pump or the equalization tank, thus forming a closed-loop treatment circuit.

[0010] Preferably, the inlet manifold consists of a main pipe connected to the inlet of the electrochemical reaction chamber and several equally spaced parallel branches. Each branch is provided with a throttling orifice or micro-valve at the end, and the flow guide is a removable and washable grid or mesh structure.

[0011] Preferably, the multi-channel electrode stack consists of anode plates and cathode plates stacked alternately and spaced by an insulating sealing frame to form multiple parallel inter-plate flow channels. The electrode plates have a mesh or perforated plate structure, and the thickness of the insulating sealing frame determines the width of the flow channels, which ranges from 1 to 10 mm.

[0012] Preferably, the phosphorus removal active layer is a lanthanum-containing compound active layer supported on the anode surface, wherein the lanthanum-containing compound is lanthanum hydroxide or a complex of lanthanum hydroxide and a conductive support.

[0013] Preferably, the top annular pipe is arranged circumferentially along the top surface of the cavity and has a slight slope pointing to its highest point, where the automatic exhaust valve is located; the top annular pipe also serves as a spray distribution pipe for top flushing or backflushing cleaning, and has a cleaning fluid inlet that is linked to the valve assembly.

[0014] Preferably, the gas-liquid separator is provided with an energy dissipation baffle zone, a gravity settling zone and a demisting unit in sequence along the airflow direction inside the gas-liquid separator, and a drain port is provided at the bottom of the separator and a clean gas discharge port is provided at the top.

[0015] Preferably, the inlet online monitoring section is equipped with pH, ​​conductivity (EC) and temperature sensors, whose monitoring signals are used for closed-loop control of the metering pump and interlocking with the valve group. The outlet online monitoring section is equipped with total phosphorus (TP), turbidity, pH, conductivity (EC) and temperature sensors, whose monitoring signals are interlocked with the three-way switching valve.

[0016] Preferably, the three-way switching valve is an electric three-way ball valve, which uses an L-shaped flow channel to switch the outlet water between the product water branch and the return water branch.

[0017] Preferably, the electrochemical reaction chamber is further provided with a busbar for uniformly distributing power to the multi-channel electrode stack and an adjustable pressure plate for ensuring the sealing of the electrode stack.

[0018] Compared with the prior art, the present invention has the following beneficial effects: (1) This utility model ensures the flow uniformity of the multi-channel electrode stack by setting up a two-stage distribution and rectification design of inlet manifold and flow guide grid, avoids local overload, and improves the overall reaction efficiency and electrode material utilization rate. (2) This utility model, through the design of the top ring pipe and gas-liquid separator, can automatically and continuously remove reaction gas, effectively prevent gas blockage, and ensure uniform current distribution and stability of online monitoring signals; (3) By setting up the linkage between online monitoring, three-way valve and reflux pump, this utility model realizes real-time judgment and automatic feedback control of effluent water quality, ensuring that the final water production meets the standards and greatly improving the reliability of operation; (4) The valve group design of this utility model integrates multiple modes such as operation, backflushing and CIP. The top ring pipe also serves as a cleaning channel, realizing smooth and safe switching between different working conditions, reducing maintenance difficulty and equipment impact risk; (5) This utility model integrates multiple functional units into one device with a reasonable layout, reduces reliance on external pipelines, occupies a small area, and is very suitable for engineering applications. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the electrochemical integrated device for phosphorus removal from wastewater provided by this utility model.

[0020] The corresponding names of the attached figures are as follows: 1-Equalization tank; 2-Coarse filtration unit; 3-Valve group; 4-Inlet online monitoring section; 5-Flow meter; 6-Metering pump; 7-Reserved functional section; 8-Inlet manifold; 9-Flow guide grid; 10-Multi-channel electrode stack; 11-Main channel; 12-Phosphorus removal active layer; 13-Pressure plate; 14-Manifold; 15-Top ring pipe; 16-Outlet short pipe; 17-Gas-liquid separator; 18-Automatic air vent valve; 19-Effluent online monitoring section; 20-Three-way switching valve; 21-Check valve; 22-Return pump. Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments. The embodiments of the present invention include, but are not limited to, the following embodiments.

[0022] Example 1: like Figure 1 As shown, this utility model provides an integrated electrochemical device for phosphorus removal from wastewater, comprising: an influent flow stabilization unit, an electrochemical reaction chamber, a gas-liquid separation system, and an effluent monitoring and reflux unit. The influent flow stabilization unit is used to stabilize the flow rate and water quality of the raw water, and includes an equalization tank 1, a coarse filter unit 2, a valve group 3, an online influent monitoring section 4, a flow meter 5, and a metering pump 6. The inlet of the electrochemical reaction chamber is connected to the outlet of the influent flow stabilization unit. The electrochemical reaction chamber is equipped with an inlet manifold 8, a flow guide grid 9, a multi-channel electrode stack 10, a main flow channel 11 located at the bottom of the chamber for collecting effluent, and an outlet short pipe 16. The anode area of ​​the multi-channel electrode stack 10 is equipped with phosphorus removal active material. Layer 12; The gas-liquid separation system includes a ring pipe installed at the top of the electrochemical reaction chamber, an automatic exhaust valve 18 connected to the high point of the ring pipe, and a gas-liquid separation tank 17, used to separate and discharge the gas generated during the reaction process; The effluent monitoring and reflux unit includes an online effluent monitoring section 19, a three-way switching valve 20, a check valve 21, and a reflux pump 22. The inlet and outlet short pipes 16 of the online effluent monitoring section 19 are connected, and the common port of the three-way switching valve 20 is connected to the outlet of the online effluent monitoring section 19. Its first outlet leads to the product water branch, and the second outlet, after passing through the check valve 21 and the reflux pump 22, is reconnected to the upstream of the metering pump 6 or the equalization tank 1, thereby forming a closed-loop processing circuit.

[0023] Furthermore, the inlet manifold 8 consists of a main pipe connected to the inlet of the electrochemical reaction chamber and several equally spaced parallel branches. Each branch is equipped with a throttling orifice or a micro-valve at its end, and the flow guide 9 is a removable and washable grid or mesh structure.

[0024] Furthermore, the multi-channel electrode stack 10 is composed of multiple identical unit modules stacked repeatedly. Each unit module includes, from top to bottom: a cathode plate, an upper insulating sealing frame, an anode plate, and a lower insulating sealing frame. Both the anode and cathode plates are made of highly conductive materials. To promote water flow and ion migration, the electrode plates preferably adopt a mesh, perforated plate, or porous plate structure. The insulating sealing frame is made of an insulating, corrosion-resistant, and somewhat elastic material (such as polytetrafluoroethylene (PTFE), polypropylene (PP), or rubber), and is ring-shaped, placed between the two electrode plates. Its thickness precisely defines the width of the flow channel between the plates. This width is a key parameter affecting reaction efficiency and pressure drop, and is usually designed to be between 1-10 mm depending on the water quality and throughput requirements. By aligning multiple of the above unit modules, a repeating structure of "cathode plate-sealing frame-anode plate-sealing frame-cathode plate..." is formed. Sufficient clamping force is applied to both sides of the entire stack via pressure plates 13, causing the insulating sealing frame to elastically deform, thereby forming a reliable seal between all electrode plates and preventing water leakage between flow channels. All anode plates are connected in parallel to the positive terminal of the DC power supply via busbars 14, and all cathode plates are connected in parallel to the negative terminal of the DC power supply, ensuring that the current is evenly distributed to each electrode reaction unit. The multi-channel electrode stack 10 adopts a modular stacked design of "electrode plate-sealing frame". The flow channel width is precisely defined by the sealing frame, resulting in a stable structure, reliable sealing, and easy assembly and maintenance.

[0025] Furthermore, the phosphorus removal active layer 12 is a lanthanum-containing compound active layer supported on the anode surface, wherein the lanthanum-containing compound is lanthanum hydroxide or a complex of it and a conductive support.

[0026] Furthermore, the top ring pipe 15 is arranged circumferentially along the top surface of the cavity and has a slight slope pointing to its highest point, where the automatic exhaust valve 18 is located; the top ring pipe 15 also serves as a spray distribution pipe for top flushing or backflushing cleaning, and has a cleaning liquid inlet that is linked with the valve group 3.

[0027] Furthermore, the gas-liquid separator 17 is provided with an energy dissipation baffle zone, a gravity settling zone and a demisting unit in sequence along the airflow direction. The bottom of the tank is provided with a drain port and the top is provided with a clean gas discharge port.

[0028] Furthermore, the inlet online monitoring section 4 is equipped with sensors for pH, conductivity (EC) and temperature, and its monitoring signals are used for closed-loop control of metering pump 6 and interlocking with valve group 3. The outlet online monitoring section 19 is equipped with sensors for total phosphorus (TP), turbidity, pH, conductivity (EC) and temperature, and its monitoring signals are interlocked with three-way switching valve 20.

[0029] Furthermore, the three-way switching valve 20 is an electric three-way ball valve, which uses an L-shaped flow channel to switch the outlet water between the product water branch and the return water branch.

[0030] Furthermore, the electrochemical reaction chamber is also equipped with a busbar 14 for uniformly distributing power to the multi-channel electrode stack 10 and an adjustable pressure plate 13 for ensuring the sealing of the electrode stack.

[0031] Furthermore, a reserved functional section 7 is reserved at the front end of the inlet manifold 8 for the subsequent upgrade of the device to add other equipment, thereby facilitating the upgrade and modification of the subsequent equipment.

[0032] Raw water first enters equalization tank 1 to equalize water volume and quality, and to initially remove some dissolved gases. Then, the water flows through coarse filtration unit 2 (such as a basket filter) to remove larger particles, protecting subsequent precision components. After passing through valve group 3, a portion of the water flows into the bypass flow tank of the inlet online monitoring section 4, where pH, conductivity (EC), and temperature (T) are monitored in real time. The main water flow is metered by flow meter 5 and then delivered to the electrochemical reaction chamber by metering pump 6 at a precisely set flow rate.

[0033] At the inlet of the reaction chamber, water flows into the inlet manifold 8. This manifold distributes the water flow evenly through its multiple equidistant parallel branches and throttling structures at the ends of the branches. Subsequently, the water flows through a removable and washable guide grid 9, further trapping fine impurities and rectifying the fluid flow before entering the multi-channel electrode stack 10 in an optimal flow state. These measures ensure the uniformity of the flow rate in the multi-channel electrode stack 10, prevent local overload, and improve the overall reaction efficiency and electrode material utilization rate.

[0034] Inside the electrode stack, water flows through a narrow channel between the anode and cathode plates. The phosphorus-removing active layer 12 on the anode surface efficiently adsorbs phosphate ions through coordination and complexation mechanisms under the influence of an electric field, achieving deep phosphorus removal. The treated liquid, after the reaction is complete, collects in the main flow channel 11 at the bottom of the chamber and is discharged through the outlet short pipe 16.

[0035] After discharge, the treated liquid enters the online monitoring section 19 for continuous monitoring of total phosphorus (TP), turbidity, pH, EC, and temperature. The control system presets a total phosphorus threshold (e.g., 0.5 mg / L) and a time delay (e.g., 30 seconds) to prevent fluctuations. If the test data consistently meets the standards, the electric three-way switching valve 20 is switched to the product water outlet, and qualified product water is discharged or reused. If the test results fail to meet the standards, the three-way switching valve 20 immediately switches to the return outlet. The substandard water is then pumped back to the mixing point upstream of the metering pump 6 or below the liquid level in the equalization tank 1 via the check valve 21 (to prevent backflow) by the return pump 22. It is then mixed with the raw water and treated again until it meets the standards. Through the linkage between online monitoring, the three-way valve, and the return pump 22, real-time judgment and automatic feedback control of the effluent quality are achieved, ensuring that the final product water meets the standards and significantly improving operational reliability.

[0036] Meanwhile, the gas generated by the electrochemical reaction accumulates at the top of the chamber, is collected by the slightly sloping top annular pipe 15, and directed to the automatic exhaust valve 18 at the highest point. The gas, along with a small amount of entrained liquid droplets, enters the gas-liquid separator 17. After internal energy dissipation, gravity settling, and demisting, the clean gas is discharged from the top of the separator, while the separated liquid flows back to the system's low-pressure point from the bottom. The design of the top annular pipe 15 and the gas-liquid separator 17 automatically and continuously removes the reaction gas, effectively preventing gas blockage and ensuring uniform current distribution and stability of the online monitoring signal.

[0037] Valve assembly 3 offers three valve positions: Run, Backflush, and CIP, allowing switching between different operating conditions, i.e., switching between different liquid flow channels. During top flushing, cleaning fluid is sprayed from the nozzle of the top ring pipe 15 to clean the electrode surface; during backflushing, cleaning fluid flows in the reverse direction from the main flow channel 11 to flush away deposits; during chemical cleaning (CIP), a specific agent (such as dilute alkali) is circulated through a dedicated pipeline, and the waste liquid after cleaning is directly discharged into the neutralization or waste liquid system, without entering the product water / return loop. After cleaning, the valve assembly switches back to the Run position, and waits for continuous confirmation of water quality compliance in the effluent monitoring section before switching back to the product water mode. Valve assembly 3 integrates multiple modes including Run, Backflush, and CIP, with the top ring pipe 15 also serving as a cleaning channel, achieving smooth and safe switching between different operating conditions, reducing maintenance difficulty and equipment impact risks.

Claims

1. An electrochemical integrated device for phosphorus removal from wastewater, characterized in that, include: Inlet water flow stabilization unit, electrochemical reaction chamber, gas-liquid separation system and outlet water monitoring and reflux unit; The inlet flow stabilization unit is used to stabilize the flow rate and water quality of the raw water, including a balance tank (1), a coarse filter unit (2), a valve group (3), an inlet online monitoring section (4), a flow meter (5), and a metering pump (6). The inlet of the electrochemical reaction chamber is connected to the outlet of the water inlet stabilization unit. The electrochemical reaction chamber is provided with an inlet manifold (8), a flow guide grid (9), a multi-channel electrode stack (10), a main channel (11) located at the bottom of the chamber for collecting outflow water, and an outlet short pipe (16). The anode area of ​​the multi-channel electrode stack (10) is provided with a phosphorus removal active layer (12). The gas-liquid separation system includes a ring pipe located at the top of the electrochemical reaction chamber, an automatic exhaust valve (18) connected to the high point of the ring pipe, and a gas-liquid separation tank (17) for separating and discharging the gas generated during the reaction process. The effluent monitoring and reflux unit includes an online effluent monitoring section (19), a three-way switching valve (20), a check valve (21), and a reflux pump (22). The inlet of the online effluent monitoring section (19) is connected to the outlet short pipe (16). The common port of the three-way switching valve (20) is connected to the outlet of the online effluent monitoring section (19). The first outlet of the three-way switching valve (20) leads to the product water branch. The second outlet of the three-way switching valve (20) is connected back to the upstream of the metering pump (6) or the equalization tank (1) after passing through the check valve (21) and the reflux pump (22).

2. The electrochemical integrated device for phosphorus removal from wastewater according to claim 1, characterized in that, The inlet manifold (8) consists of a main pipe connected to the inlet of the electrochemical reaction chamber and several parallel branches connected at equal intervals. The end of each branch is provided with a throttling orifice or a micro valve. The guide grid (9) is a detachable and washable grid or mesh structure.

3. The electrochemical integrated device for phosphorus removal from wastewater according to claim 1, characterized in that, The multi-channel electrode stack (10) consists of anode plates and cathode plates stacked alternately and interspersed by an insulating and sealed frame to form multiple parallel inter-plate flow channels. The electrode plates are mesh or perforated plate structures.

4. The electrochemical integrated device for phosphorus removal from wastewater according to claim 3, characterized in that, The phosphorus removal active layer (12) is a lanthanum-containing compound active layer loaded on the anode surface.

5. The electrochemical integrated device for phosphorus removal from wastewater according to claim 1, characterized in that, The top ring pipe (15) is arranged circumferentially along the top surface of the cavity, and the top ring pipe (15) is provided with a cleaning fluid inlet and is linked with the valve group (3).

6. An electrochemical integrated device for phosphorus removal from wastewater according to claim 1 or 5, characterized in that, The gas-liquid separator (17) is provided with an energy dissipation deflection zone, a gravity settling zone and a demisting unit in sequence along the airflow direction. The gas-liquid separator (17) is provided with a drain port at the bottom and a clean gas discharge port at the top.

7. The electrochemical integrated device for phosphorus removal from wastewater according to claim 1, characterized in that, The inlet online monitoring section (4) is equipped with pH, ​​conductivity and temperature sensors. Its monitoring signals are used to perform closed-loop control of the metering pump (6) and interlock with the valve group (3). The outlet online monitoring section (19) is equipped with total phosphorus, turbidity, pH, conductivity and temperature sensors. Its monitoring signals are interlocked with the three-way switching valve (20).

8. The electrochemical integrated device for phosphorus removal from wastewater according to claim 1, characterized in that, The three-way switching valve (20) is an electric three-way ball valve, which realizes the switching of water output between the production water branch and the return water branch.

9. An electrochemical integrated device for phosphorus removal from wastewater according to claim 1, characterized in that, The electrochemical reaction chamber is also provided with a busbar (14) for uniformly distributing power to the multi-channel electrode stack (10) and a pressure plate (13) for ensuring the sealing of the multi-channel electrode stack (10).

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