High-recovery-rate short-process salt-resistant reverse osmosis system and treatment method

Abstract

The invention relates to the technical field of water treatment, in particular to a high-recovery-rate short-process salt-tolerant reverse osmosis system and treatment method.The system comprises a pretreatment unit, a sensor monitoring unit, a self-adaptive pressure-flow coupling control unit, an intelligent operation and maintenance unit and a gradient boosting reverse osmosis membrane set. According to the invention, ultrahigh recovery rate and desalination performance are realized, gradient boost membrane module design is combined with concentration polarization inhibition technology, membrane surface flow state distribution is optimized, osmotic pressure influence is significantly reduced, pressure-flow coupling control and concentrated water excess pressure energy recovery technology are integrated, energy dynamic cyclic utilization is realized, energy consumption is reduced, and the method is suitable for industrial production. By monitoring the membrane flux attenuation rate and the transmembrane pressure difference in real time and dynamically optimizing a pulse cleaning strategy, dynamic optimization of high-salinity wastewater treatment is realized, and the problems of low recovery rate, high energy consumption and quick membrane pollution in high-salinity wastewater treatment are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of water treatment, and in particular to a high-recovery, short-process, salt-tolerant reverse osmosis system and a treatment method. Background Art

[0002] With increasingly stringent requirements for zero discharge (ZLD) of industrial wastewater, the efficient treatment of high-salinity wastewater (TDS ≥ 10,000 mg / L) has become a major environmental challenge. Reverse osmosis (RO) technology is widely used for wastewater concentration due to its high desalination capacity, but existing systems still face the following key challenges under high-salinity conditions:

[0003] 1. Low recovery rate and poor operating stability

[0004] Traditional RO systems are limited by osmotic pressure, with recovery rates generally below 75%. High-salt wastewater treatment requires multiple stages in series, resulting in lengthy processes and a surge in energy consumption.

[0005] Under high-salinity conditions, membrane flux decays rapidly, and operating efficiency decreases exponentially with increasing influent salinity, resulting in frequent system start-up and shutdown maintenance.

[0006] 2. Membrane fouling and scaling problems are prominent

[0007] Polyamide composite membranes have poor chlorine resistance (<0.1ppm residual chlorine) and are easily contaminated by organic / inorganic scale (such as CaSO4, SiO2). Chemical cleaning cycles are short (usually 1-3 months), increasing reagent costs and membrane lifespan.

[0008] The uneven distribution of fluid on the concentrate side causes severe concentration polarization, and the local salinity can reach 3-5 times that of the main fluid, accelerating scaling on the membrane surface.

[0009] 3. Insufficient system energy efficiency and intelligence

[0010] The multi-stage RO series process requires an intermediate booster pump, and the power consumption per ton of water is as high as 3.5-4.5kWh / m 3 , the energy recovery rate is less than 30%;

[0011] The lack of real-time control means makes it impossible to dynamically optimize pressure and recovery rate according to changes in influent salinity and temperature, resulting in energy waste or the risk of membrane overload.

[0012] In recent years, researchers have attempted to improve this through the following approaches:

[0013] Membrane material modification: For example, adding graphene can improve the chlorine resistance of polyamide membranes, but the improvement in anti-fouling performance is limited (the flux attenuation rate is still >20% / month);

[0014] Fluid optimization: Using vortex generators to improve the concentrate side flow pattern only alleviates local concentration polarization and does not solve the system-level energy efficiency problem;

[0015] Intermittent operation: Delays contamination through pulse backwashing, but reduces the effective water production time by more than 15%.

[0016] The above methods have not been able to fundamentally break through the high recovery rate (> 85%), low energy consumption (< 2.5kWh / m 3 ), long-term stable operation (chemical cleaning interval > 6 months). No solution has been proposed for related technical problems. Summary of the Invention

[0017] In response to the problems in the related technology, the present invention proposes a high-recovery, short-process, salt-tolerant reverse osmosis system and treatment method to overcome the above-mentioned technical problems existing in the existing related technology. The purpose of the present invention is to achieve ultra-high recovery rate and desalination performance. The gradient boost membrane group design is combined with concentration polarization suppression technology to optimize the flow distribution on the membrane surface, significantly reduce the influence of osmotic pressure, integrate pressure-flow coupling control and concentrated water residual pressure energy recovery technology to achieve dynamic energy recycling and reduce energy consumption. By real-time monitoring of membrane flux attenuation rate and transmembrane pressure difference, dynamic optimization of pulse cleaning strategy is achieved to achieve dynamic optimization of high-salt wastewater treatment, and solve the problems of low recovery rate, high energy consumption and rapid membrane pollution in high-salt wastewater treatment.

[0018] To achieve the above object, the present invention provides the following technical solution: a high-recovery, short-process, salt-tolerant reverse osmosis system, comprising:

[0019] Pretreatment unit: used to remove suspended solids and organic matter in wastewater, including ultrafiltration membrane and activated carbon adsorption unit;

[0020] Sensor monitoring unit: used to detect the influent TDS value, pH value, temperature, membrane flux and transmembrane pressure difference in real time;

[0021] Adaptive pressure-flow coupling control unit: includes a high-pressure pump, a concentrated water return flow regulating valve, and an energy recovery device, used to dynamically adjust system operating parameters;

[0022] Intelligent operation and maintenance unit: predicts membrane fouling trends based on time series data analysis and triggers pulse backwashing and chemical cleaning;

[0023] Gradient boost reverse osmosis membrane group: adopts multi-stage RO membrane structure, combined with segment-level high-pressure pump to achieve concentrated water residual pressure energy recovery.

[0024] Preferably, the adaptive pressure-flow coupling control unit includes:

[0025] Conductivity sensor and pressure transmitter for real-time monitoring of inlet water salinity and membrane module pressure;

[0026] The variable frequency high-pressure pump dynamically adjusts the initial pressure according to the TDS value and sets the base pressure according to the formula P = 0.02 × TDS + 15;

[0027] The energy recovery device transfers the excess pressure of concentrated water to the water inlet side, reducing the system energy consumption to 2.1kWh / m 3 the following.

[0028] Preferably, the intelligent operation and maintenance unit includes:

[0029] The neural network-based PID controller has input parameters including membrane flux decay rate, transmembrane pressure difference and inlet water quality data;

[0030] Pulse recoil module triggers 20-30s gas-water mixed recoil every 4-6 hours of operation;

[0031] Predictive cleaning module extends chemical cleaning cycle to more than 6 months.

[0032] Preferably, the air pressure of the air-water mixed backwash is 0.8-1.2 MPa, and the water pressure is 0.3-0.5 MPa.

[0033] Preferably, the gradient boost reverse osmosis membrane group adopts a multi-stage design, including:

[0034] The first section of RO membrane group has an initial pressure of 45-75 bar;

[0035] The second section of the RO membrane group uses a high-pressure pump to increase the pressure and recover the residual pressure of the concentrated water;

[0036] When the pressure increase exceeds 55%, the segment-level high-pressure pump is triggered to maintain the system recovery rate at 85-92%.

[0037] The present invention also provides the following technical solutions:

[0038] A high-recovery, short-process, salt-tolerant reverse osmosis treatment method comprises the following steps:

[0039] S1. Pretreatment and parameter testing: Remove suspended solids and organic matter through multi-stage filtration, and simultaneously test the inlet water TDS, pH and temperature;

[0040] S2. Dynamic loading of the membrane system: Adjust the initial pressure of the high-pressure pump according to the test data, and determine the base pressure according to the formula P = 0.02 × TDS + 15;

[0041] S3. Gradient pressure recovery control: Increase operating pressure at a rate of 3-5 bar / min, monitor concentrate pressure, and trigger the segment-level high-pressure pumps to maintain a recovery rate of 85-92%;

[0042] S4. Pulse membrane fouling control: Start 20-30s gas-water mixing backwash every 4-6 hours, and the backwash parameters are dynamically optimized by the PID controller;

[0043] S5. Energy recovery and discharge: The residual pressure of the concentrated water is recycled to the water inlet side through the segment-level high-pressure pump, reducing the system energy consumption by 25-40%. Finally, the concentrated water enters the evaporation crystallization unit.

[0044] Preferably, in step S3:

[0045] The concentrated water energy is adjusted in real time by the PID controller to adjust the frequency of the high-pressure pump and the opening of the concentrated water return flow;

[0046] The PID controller is an adaptive neural network model, and its input parameters include membrane flux attenuation rate, transmembrane pressure difference and inlet water quality data.

[0047] Preferably, in step S4:

[0048] The backwash cycle is dynamically adjusted based on the membrane fouling trend, using a mixed pulse mode of 0.8-1.2MPa air pressure and 0.3-0.5MPa water pressure;

[0049] The chemical cleaning cycle is extended to more than 6 months, reducing the frequency of membrane replacement.

[0050] Preferably, the final system water recovery rate is ≥90%, and the concentrated water TDS is ≥150,000 mg / L, and can directly enter the evaporation crystallization unit.

[0051] Compared with the prior art, the present invention has the following beneficial effects:

[0052] (1) The present invention is a high-recovery, short-process, salt-tolerant reverse osmosis system and treatment method with ultra-high recovery and desalination performance. It adopts a gradient boost membrane group design combined with concentration polarization suppression technology to optimize the flow distribution on the membrane surface and significantly reduce the influence of osmotic pressure. Under high-salt conditions with TDS ≥ 10,000 ppm, the single-stage reverse osmosis recovery rate is increased from 65-75% of the traditional process to 85-95%, and the desalination rate is stably maintained at ≥ 99.5%. The TDS of concentrated water can reach above 150,000 ppm, directly meeting the feed requirements of the evaporation crystallization unit.

[0053] (2) The present invention is a high-recovery, short-process, salt-tolerant reverse osmosis system and treatment method, which greatly reduces energy consumption, integrates pressure-flow coupling control and concentrated water residual pressure energy recovery technology, and realizes dynamic energy recycling. The system's electricity consumption per ton of water is reduced from 3.5-4.5kWh / m2 of the traditional process. 3 Reduced to 2.1kWh / m 3 Below, energy saving efficiency reaches 40-50%;

[0054] (3) The present invention provides a high-recovery, short-process, salt-tolerant reverse osmosis system and treatment method. By real-time monitoring of the membrane flux attenuation rate and transmembrane pressure difference, the pulse cleaning strategy is dynamically optimized. The chemical cleaning cycle is extended from 1-3 months in traditional processes to more than 6 months, the membrane life is increased by 2-3 times, and the operation and maintenance costs are reduced by 35%;

[0055] (4) The present invention provides a high-recovery, short-process, salt-tolerant reverse osmosis system and treatment method. An adaptive pressure control algorithm combined with multi-parameter feedback achieves dynamic optimization of high-salinity wastewater treatment. It can adapt to a wide range of influent water with a TDS of 5,000-50,000 ppm, and has a recovery rate fluctuation of <±3%, significantly better than the ±10% fluctuation of conventional processes.

[0056] (5) The present invention is a high-recovery, short-process, salt-tolerant reverse osmosis system and treatment method. High-purity concentrated water is directly recycled, and the salt product is added value by coupling evaporation and crystallization. The purity of the crystallized salt reaches the industrial first-level standard GB / T5462-2015. Compared with traditional mixed salt (purity <90%), the added value is increased by 200%. It solves the problems of low recovery rate, high energy consumption, and rapid membrane fouling in the treatment of high-salt wastewater. It has both technological advancement and economic feasibility, and provides a new solution for zero discharge of industrial wastewater. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 is a block diagram of the system of the present invention;

[0058] Figure 2 and Figure 3 This is the data of the embodiment of the present invention. DETAILED DESCRIPTION

[0059] The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present invention.

[0060] Example 1

[0061] See also Figure 1-3 The present invention proposes a high-recovery, short-process, salt-tolerant reverse osmosis system and a treatment method. A high-recovery, short-process, salt-tolerant reverse osmosis system comprises:

[0062] Pretreatment unit: used to remove suspended solids and organic matter in wastewater, including ultrafiltration membrane and activated carbon adsorption unit;

[0063] Sensor monitoring unit: used to detect the influent TDS value, pH value, temperature, membrane flux and transmembrane pressure difference in real time;

[0064] Adaptive pressure-flow coupling control unit: includes a high-pressure pump, a concentrated water return flow regulating valve, and an energy recovery device, used to dynamically adjust system operating parameters;

[0065] Intelligent operation and maintenance unit: predicts membrane fouling trends based on time series data analysis and triggers pulse backwashing and chemical cleaning;

[0066] Gradient boost reverse osmosis membrane group: adopts multi-stage RO membrane structure, combined with segment-level high-pressure pump to achieve concentrated water residual pressure energy recovery.

[0067] Furthermore, the adaptive pressure-flow coupling control unit includes:

[0068] Conductivity sensor and pressure transmitter for real-time monitoring of inlet water salinity and membrane module pressure;

[0069] The variable frequency high-pressure pump dynamically adjusts the initial pressure according to the TDS value and sets the base pressure according to the formula P = 0.02 × TDS + 15;

[0070] The energy recovery device transfers the excess pressure of concentrated water to the water inlet side, reducing the system energy consumption to 2.1kWh / m 3 the following.

[0071] Furthermore, the intelligent operation and maintenance unit includes:

[0072] The neural network-based PID controller has input parameters including membrane flux decay rate, transmembrane pressure difference and inlet water quality data;

[0073] Pulse recoil module triggers 20-30s gas-water mixed recoil every 4-6 hours of operation;

[0074] Predictive cleaning module extends chemical cleaning cycle to more than 6 months.

[0075] Furthermore, the air pressure of the air-water mixed backwash is 0.8-1.2 MPa, and the water pressure is 0.3-0.5 MPa.

[0076] Furthermore, the gradient boost reverse osmosis membrane group adopts a multi-stage design, including:

[0077] The first section of RO membrane group has an initial pressure of 45-75 bar;

[0078] The second section of the RO membrane group uses a high-pressure pump to increase the pressure and recover the residual pressure of the concentrated water;

[0079] When the pressure increase exceeds 55%, the segment-level high-pressure pump is triggered to maintain the system recovery rate at 85-92%.

[0080] The present invention also provides the following technical solutions:

[0081] A high-recovery, short-process, salt-tolerant reverse osmosis treatment method comprises the following steps:

[0082] S1. Pretreatment and parameter testing: Remove suspended solids and organic matter through multi-stage filtration, and simultaneously test the inlet water TDS, pH and temperature;

[0083] S2. Dynamic loading of the membrane system: Adjust the initial pressure of the high-pressure pump according to the test data, and determine the base pressure according to the formula P = 0.02 × TDS + 15;

[0084] S3. Gradient pressure recovery control: Increase operating pressure at a rate of 3-5 bar / min, monitor concentrate pressure, and trigger the segment-level high-pressure pumps to maintain a recovery rate of 85-92%;

[0085] S4. Pulse membrane fouling control: Start 20-30s gas-water mixing backwash every 4-6 hours, and the backwash parameters are dynamically optimized by the PID controller;

[0086] S5. Energy recovery and discharge: The residual pressure of the concentrated water is recycled to the water inlet side through the segment-level high-pressure pump, reducing the system energy consumption by 25-40%. Finally, the concentrated water enters the evaporation crystallization unit.

[0087] Furthermore, in step S3:

[0088] The concentrated water energy is adjusted in real time by the PID controller to adjust the frequency of the high-pressure pump and the opening of the concentrated water return flow;

[0089] The PID controller is an adaptive neural network model, and its input parameters include membrane flux attenuation rate, transmembrane pressure difference and inlet water quality data.

[0090] Furthermore, in step S4:

[0091] The backwash cycle is dynamically adjusted based on the membrane fouling trend, using a mixed pulse mode of 0.8-1.2MPa air pressure and 0.3-0.5MPa water pressure;

[0092] The chemical cleaning cycle is extended to more than 6 months, reducing the frequency of membrane replacement.

[0093] Furthermore, the final system water recovery rate is ≥90%, and the concentrated water TDS is ≥150,000 mg / L, which can directly enter the evaporation crystallization unit.

[0094] Take the treatment of high-salt chemical wastewater from coal chemical industry as an example:

[0095] Influent conditions: TDS: 10,000ppm, COD: 40mg / L, pH: 8.3.

[0096] Implementation parameters:

[0097] The operating pressure is 65 bar, the recovery rate is 85-92%, and the desalination rate is greater than 95%.

[0098] Membrane element arrangement: 3 sections with 6 elements, concentrated water return rate 15%.

[0099] Effect data:

[0100] The conductivity of produced water is less than 1000ppm, meeting the GB / T 19923-2024 industrial reuse standard;

[0101] System energy consumption 2.3kWh / m 3 , annual operation and maintenance costs are reduced by 32%.

[0102] Step 1: Pressure Dynamic Control

[0103] According to the formula P = 0.02 × 32000 + 15 = 655 bar → the initial pressure is set to 65 bar

[0104] High-pressure pump inverter startup curve: 0→65bar linear pressure increase takes 780 seconds.

[0105] Step 2: Gradient pressure increase and reflux

[0106] Pressure increase rate: 3-5 bar / min (total running time 13 minutes to 65 bar)

[0107] When the conductivity of the concentrated water increased from 65,000 μS / cm to 74,800 μS / cm (an increase of 15%), 15% concentrated water reflux was started.

[0108] Step 3: Smart Recoil

[0109] PID model output recoil cycle: 90 seconds pulse recoil every 5 hours

[0110] Membrane flux recovery rate after backflushing: 98.3% (compared to 91.7% of traditional timed backflushing).

[0111] Step 4: Energy Recovery

[0112] Concentrated water pressure recovery efficiency: 92%

[0113] {Inlet pressure 32 bar → Concentrated water pressure 32 bar → High pressure 62 bar [62-32 bar, actual output 30 bar]};

[0114] System comprehensive energy consumption: 2.4kWh / m 3 (Comparison value of traditional system is 3.8kWh / m 3 ).

[0115] The effect verification data is shown in Table 1 below:

[0116]

[0117]

[0118] Table 1 Effect verification data

[0119] The present invention has ultra-high recovery rate and desalination performance. It adopts gradient boost membrane group design combined with concentration polarization suppression technology to optimize the flow distribution on the membrane surface and significantly reduce the influence of osmotic pressure. Under high-salt conditions with TDS ≥ 10,000 ppm, the single-stage reverse osmosis recovery rate is increased from 65-75% of the traditional process to 85-95%, and the desalination rate is stably maintained at ≥ 99.5%. The TDS of concentrated water can reach above 150,000 ppm, directly meeting the feed requirements of the evaporation crystallization unit; it greatly reduces energy consumption, integrates pressure-flow coupling control and concentrated water residual pressure energy recovery technology, realizes dynamic energy recycling, and the system power consumption per ton of water is reduced from 3.5-4.5 kWh / m 3 Reduced to 2.1kWh / m 3 By dynamically optimizing pulse cleaning strategies through real-time monitoring of membrane flux decay and transmembrane pressure, the system extends the chemical cleaning cycle from 1-3 months in traditional processes to over 6 months, increasing membrane life by 2-3 times and reducing operation and maintenance costs by 35%. An adaptive pressure control algorithm, combined with multi-parameter feedback, dynamically optimizes high-salinity wastewater treatment, accommodating a wide range of influent TDS levels from 5,000 to 50,000 ppm. The system achieves a recovery rate fluctuation of <±3%, significantly superior to the ±10% fluctuation observed in traditional processes. High-purity concentrated water is directly recycled, coupled with evaporation and crystallization to increase the value of the salt product. The purity of the crystallized salt meets the GB / T 5462-2015 industrial grade 1 standard, representing a 200% increase in added value compared to traditional mixed salt (purity <90%). This addresses the challenges of low recovery, high energy consumption, and rapid membrane fouling in high-salinity wastewater treatment. Combining technological advancement with economic feasibility, it provides a novel solution for zero industrial wastewater discharge.

[0120] Alternative 1: Modification of the flow channel geometry

[0121] Technical features: The linear guide groove is changed to a spiral pattern or fractal structure

[0122] Implementation effect:

[0123] The spiral guide groove induces concentrated water swirl, reducing the boundary layer thickness (concentration polarization coefficient decreases by 18%);

[0124] Fractal structure optimizes flow field distribution uniformity (the flow velocity difference across the membrane is reduced from ±15% to ±7%);

[0125] Example data: The recovery rate of the spiral guide groove system is increased to 93% (compared to 90% of the original design).

[0126] Alternative 2: Energy Recovery Device Replacement

[0127] Technical features: The PX supercharger is replaced by a turbine-type energy recovery device (ERD) or a hydraulic motor.

[0128] Implementation effect:

[0129] Turbine ERD is suitable for large flow scenarios (>500m 3 / d), energy recovery efficiency ≥85%;

[0130] The hydraulic motor realizes direct conversion of pressure energy into mechanical energy, reducing power loss;

[0131] Example data: Turbine ERD system comprehensive energy consumption 2.6kWh / m 3 (Compared to the PX solution’s 2.4kWh / m 3 ).

[0132] Alternative 3: Optimizing the pressure regulation formula

[0133] Technical features: The original formula P = 0.02 × TDS + 15 is changed to a piecewise function:

[0134] When TDS≤25,000ppm, P=0.018×TDS+18

[0135] When TDS>25,000ppm, P=0.022×TDS+12

[0136] Implementation effect: Adapt to the nonlinear osmotic pressure changes in different salinity ranges and reduce energy consumption in high-salinity sections.

[0137] Example data: When TDS=40,000ppm, energy consumption is reduced by 7% (2.2kWh / m 3 vs the original plan 2.4kWh / m 3 ).

[0138] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A high recovery rate, short process, salt tolerance reverse osmosis system, characterized in that: include: Pretreatment unit: used to remove suspended solids and organic matter in wastewater, including ultrafiltration membrane and activated carbon adsorption unit; Sensor monitoring unit: used to detect the influent TDS value, pH value, temperature, membrane flux and transmembrane pressure difference in real time; Adaptive pressure-flow coupling control unit: includes a high-pressure pump, a concentrated water return flow regulating valve, and an energy recovery device, used to dynamically adjust system operating parameters; Intelligent operation and maintenance unit: predicts membrane fouling trends based on time series data analysis and triggers pulse backwashing and chemical cleaning; Gradient boost reverse osmosis membrane group: adopts multi-stage RO membrane structure, combined with segment-level high-pressure pump to achieve concentrated water residual pressure energy recovery.

2. The reverse osmosis system according to claim 1, characterized in that: The adaptive pressure-flow coupling control unit includes: Conductivity sensor and pressure transmitter for real-time monitoring of inlet water salinity and membrane module pressure; The variable frequency high-pressure pump dynamically adjusts the initial pressure according to the TDS value and sets the base pressure according to the formula P = 0.02 × TDS + 15; The energy recovery device transfers the excess pressure of concentrated water to the water inlet side, reducing the system energy consumption to 2.1kWh / m 3 the following.

3. The reverse osmosis system according to claim 1, characterized in that: The intelligent operation and maintenance unit includes: The neural network-based PID controller has input parameters including membrane flux decay rate, transmembrane pressure difference and inlet water quality data; Pulse recoil module triggers 20-30s gas-water mixed recoil every 4-6 hours of operation; Predictive cleaning module extends chemical cleaning cycle to more than 6 months.

4. The reverse osmosis system according to claim 3, characterized in that: The air pressure of the air-water mixed backwash is 0.8-1.2 MPa, and the water pressure is 0.3-0.5 MPa.

5. The reverse osmosis system according to claim 1, characterized in that: The gradient boost reverse osmosis membrane group adopts a multi-stage design, including: The first section of RO membrane group has an initial pressure of 45-75 bar; The second section of the RO membrane group uses a high-pressure pump to increase the pressure and recover the residual pressure of the concentrated water; When the pressure increase exceeds 55%, the segment-level high-pressure pump is triggered to maintain the system recovery rate at 85-92%.

6. A high-recovery, short-flow, salt-tolerant reverse osmosis treatment method based on any one of the reverse osmosis systems of claims 1-5, characterized in that: The following steps are involved: S1. Pretreatment and parameter testing: Remove suspended solids and organic matter through multi-stage filtration, and simultaneously test the inlet water TDS, pH and temperature; S2. Dynamic loading of the membrane system: Adjust the initial pressure of the high-pressure pump according to the test data, and determine the base pressure according to the formula P = 0.02 × TDS + 15; S3. Gradient pressure recovery control: Increase operating pressure at a rate of 3-5 bar / min, monitor concentrate pressure, and trigger the segment-level high-pressure pumps to maintain a recovery rate of 85-92%; S4. Pulse membrane fouling control: Start 20-30s gas-water mixing backwash every 4-6 hours, and the backwash parameters are dynamically optimized by the PID controller; S5. Energy recovery and discharge: The residual pressure of the concentrated water is recycled to the water inlet side through the segment-level high-pressure pump, reducing the system energy consumption by 25-40%. Finally, the concentrated water enters the evaporation crystallization unit.

7. The reverse osmosis treatment method according to claim 6, characterized in that: In step S3: The concentrated water energy is adjusted in real time by the PID controller to adjust the frequency of the high-pressure pump and the opening of the concentrated water return flow; The PID controller is an adaptive neural network model, and its input parameters include membrane flux attenuation rate, transmembrane pressure difference and inlet water quality data.

8. The reverse osmosis treatment method according to claim 6, characterized in that: In step S4: The backwash cycle is dynamically adjusted based on the membrane fouling trend, using a mixed pulse mode of 0.8-1.2MPa air pressure and 0.3-0.5MPa water pressure; The chemical cleaning cycle is extended to more than 6 months, reducing the frequency of membrane replacement.

9. The reverse osmosis treatment method according to claim 6, characterized in that: The final system water recovery rate is ≥90%, and the concentrated water TDS is ≥150,000 mg / L, which can directly enter the evaporation crystallization unit.

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