Photocatalysis-coagulation-ultrafiltration integrated short process water treatment device and regulation method

Abstract

This invention discloses an integrated short-process water treatment device and control method for photocatalysis-coagulation-ultrafiltration, belonging to the field of deep purification of drinking water micro-pollution and membrane fouling control technology. It includes: a shell with an inlet at the top, and inside the shell, arranged sequentially from top to bottom, a photocatalytic pre-oxidation module, a coagulation and flocculation module, and an ultrafiltration module; the photocatalytic pre-oxidation module includes a light source and a catalytic component, which degrades organic matter in wastewater entering through the inlet; the coagulation and flocculation module includes a coagulant dosing sub-module and a stirring sub-module, which disperse the coagulant in the wastewater after organic matter degradation; the ultrafiltration module is detachably connected to the inner wall of the shell, and includes a hollow fiber ultrafiltration membrane module and a pulse component. The hollow fiber ultrafiltration membrane module filters the wastewater passing through the coagulation and flocculation module, and the pulse component removes pollutants adhering to the hollow fiber ultrafiltration membrane module. This invention solves the problem of existing processes lacking integrated devices and adaptive control.

Description

Technical Field

[0001] This invention relates to an integrated short-process water treatment device and control method for photocatalysis-coagulation-ultrafiltration, belonging to the field of deep purification of drinking water micro-pollution and membrane fouling control technology. Background Technology

[0002] Currently, urban and rural water supply sources generally exhibit micro-pollution characteristics, with high levels of natural macromolecular organic matter such as humic acid and fulvic acid, trace algal metabolites, and colloidal suspended solids. The traditional long-process "coagulation-sedimentation-filtration-ultrafiltration" method offers stable treatment results, but it requires numerous structures, large land areas, high infrastructure investment, and complex operation and maintenance, making it unsuitable for the land use and investment needs of small rural water plants and newly constructed decentralized water supply projects. In contrast, the short-process "coagulation-ultrafiltration" method eliminates the need for independent sedimentation tanks, relying on coagulated flocs to directly enter the membrane module for filtration. It boasts advantages such as a shorter process, less land area, and faster start-up, thus becoming the mainstream approach.

[0003] In existing short-process coagulation-ultrafiltration (SCAC-UF) water, after being pumped, the raw water first enters the mixing reaction unit. Through mechanical stirring or hydraulic turbulence, the coagulant is rapidly dispersed in the water, completing hydrolysis and charge neutralization reactions. This destabilizes suspended particles, colloidal substances, and some large organic molecules, causing them to coagulate into microflocs. The mixing reaction time is typically controlled within a few minutes. Subsequently, without independent sedimentation, the mixed liquid is directly pumped under pressure or gravity flow into the ultrafiltration membrane module. The membrane module mostly uses hollow fiber or flat-sheet ultrafiltration membranes with a pore size range of 0.01μm-0.1μm. The membrane pores act as a sieve to separate the flocs and trapped pollutants into a solid-liquid mixture. The permeate enters the clear water tank, and the concentrate is discharged from the system as sludge. In terms of operation, this short-process typically employs a constant flux or constant pressure filtration mode, relying on periodic air-water backwashing or physical hydraulic flushing to loosen and remove pollutants from the membrane surface, thus restoring some membrane flux. The entire system tightly integrates the coagulation reaction and membrane separation unit, eliminating the traditional sedimentation transition stage. The overall hydraulic retention time is shortened from 1-2 hours in a conventional long process to less than 30 minutes. The structure is highly integrated, enabling modular layout and rapid start-up.

[0004] However, the existing "coagulation-ultrafiltration" short-process technology still has technical shortcomings in practical engineering applications: regarding UV... 254The characterization of macromolecular soluble organic matter has a weak degradation capacity, and these substances are highly susceptible to adsorption and blockage of membrane pores, inducing irreversible organic fouling. At the same time, the membrane module lacks the ability to actively degrade pollutants, resulting in rapid accumulation of membrane fouling, a high rate of transmembrane pressure gradient rise, frequent chemical cleaning, and shortened membrane life. Secondly, most existing short-process technologies are conducted as separate experimental studies, lacking integrated set technologies that match the device structure and process steps. Laboratory-scale processes are difficult to directly implement into engineering assembly and operation. Furthermore, most existing short-process devices cannot adaptively adjust operating parameters according to actual operating conditions, relying on manual experience for operation, resulting in poor operational stability. Summary of the Invention

[0005] The present invention provides a photocatalytic-coagulation-ultrafiltration integrated short-process water treatment device, comprising: a shell with an inlet at the top and a photocatalytic pre-oxidation module, a coagulation and flocculation module and an ultrafiltration module arranged sequentially from top to bottom inside the shell; The photocatalytic pre-oxidation module includes a light source and a catalytic component. The light source is located on the inner wall of the housing, and the catalytic component is fixed inside the housing. It is used to degrade organic matter in wastewater entering through the inlet under the catalysis of the light source. The organic matter is UV-sensitive. 254 Characterized organic matter; The coagulation and flocculation module includes a coagulant dosing submodule and a stirring submodule; the dosing port of the coagulant dosing submodule extends below the catalytic component; the stirring submodule passes through the catalytic component and is used to disperse the coagulant in the wastewater after the organic matter has been degraded. The ultrafiltration module is detachably connected to the inner wall of the housing. The ultrafiltration module includes a hollow fiber ultrafiltration membrane module and a pulse module. The surface of the hollow fiber ultrafiltration membrane module is provided with a hydrophilic modification layer for filtering wastewater passing through the coagulation and flocculation module. The pulse module is located inside the housing and is disposed on the side of the hollow fiber ultrafiltration membrane module for removing contaminants adhering to the hollow fiber ultrafiltration membrane module.

[0006] Furthermore, it also includes a linkage control module, which includes influent UV... 254 Acquisition unit and influent UV 254 The control unit connected to the acquisition unit; UV inlet water 254 The data collection unit is located at the water inlet of the casing; The control unit is also connected to the light source, coagulant dosing submodule, and pulse assembly. The control unit is used to adjust the UV levels of the influent. 254 The acquisition unit collects signals to adjust the light intensity of the light source, the dosage of the coagulant addition submodule, and the pulse mode of the pulse component.

[0007] Specifically, the linkage control module also includes an influent turbidity acquisition unit connected to the control unit; The inlet turbidity sampling unit is located at the inlet of the casing; The control unit is also connected to the cross-flow control module, which is located outside the housing and connected to the upper and lower ends of the hollow fiber ultrafiltration membrane module. The cross-flow control module is used to regulate the cross-flow rate of the hollow fiber ultrafiltration membrane module. The control unit is also used to adjust the dosage and crossflow velocity of the coagulant dosing submodule based on the signal collected by the influent turbidity acquisition unit.

[0008] Furthermore, the linkage control module also includes an ultrafiltration transmembrane pressure differential acquisition unit connected to the control unit; The ultrafiltration transmembrane pressure difference acquisition unit is located at the upper end of the hollow fiber ultrafiltration membrane module and at the product water outlet of the shell; The control unit is also used to adjust the crossflow velocity and the pulse mode of the pulse component based on the signal acquired by the ultrafiltration transmembrane pressure difference acquisition unit.

[0009] Specifically, the catalytic component is a carrier network with photocatalytic material on its surface; The photocatalytic material is a composite of one of the following: metal oxide, metal sulfide, and metal nitride, and a carbon-based material; the support mesh is one of the following: metal mesh, carbon-based mesh, and glass fiber mesh.

[0010] Specifically, the hollow fiber ultrafiltration membrane module is made of one of the following materials: polyethersulfone, polyvinylidene fluoride, polyacrylonitrile, and polyvinyl chloride; the hydrophilic modification layer contains a composite of inorganic nanomaterials and carbon-based materials, and the water contact angle of both the inorganic nanomaterials and the carbon-based materials is less than 90°.

[0011] On the other hand, the present invention also provides a method for regulating an integrated short-process water treatment device of photocatalysis-coagulation-ultrafiltration, including: S1, Collect UV data from incoming water 254 UV inlet water 254 Compared with the preset first threshold and second threshold, the first threshold is less than the second threshold; based on the comparison result, the light intensity of the light source, the reference dosage of the coagulant dosing submodule and the pulse mode of the pulse component are determined; S2. Collect the influent turbidity and compare it with the preset third and fourth thresholds. If the third threshold is less than the fourth threshold, adjust the current baseline dosage and set the current crossflow velocity based on the comparison results. S3. Collect the transmembrane pressure difference of the hollow fiber ultrafiltration membrane module, compare the transmembrane pressure difference with the preset fifth threshold and sixth threshold, and the fifth threshold is less than the sixth threshold; based on the comparison result, correct the current crossflow velocity and pulse mode.

[0012] Specifically, S1 includes: S11, When the UV inlet water is present 254When the load is ≤ the first threshold, it is determined to be the first organic load range. The control unit controls the light source to operate at the first light intensity, the coagulant dosing submodule to operate at the first dosing amount, and the pulse component to operate in the first pulse mode. S12, When the first threshold is less than the influent UV 254 When the load is ≤ the second threshold, it is determined to be in the second organic load range. The control unit controls the light source to operate at the second light intensity, the coagulant dosing submodule to operate at the second dosing amount, and the pulse component to operate in the second pulse mode. The second light intensity is greater than the first light intensity, and the second dosing amount is greater than the first dosing amount. S13, When the UV inlet water is present 254 When the load exceeds the second threshold, it is determined to be in the third organic load range. The control unit controls the light source to operate at the third light intensity, the coagulant dosing submodule to operate at the third dosing amount, and the pulse component to operate in the third pulse mode. The third light intensity is greater than the second light intensity, and the third dosing amount is greater than the second dosing amount.

[0013] Specifically, S2 includes: S21. When the influent turbidity is less than or equal to the third threshold, it is determined to be in the first turbidity range. The control unit controls the coagulant dosing submodule to reduce the dosing amount by the first ratio based on the dosage corresponding to the current organic load range, and controls the cross-flow control module to operate at the first cross-flow velocity. S22. When the third threshold < influent turbidity ≤ fourth threshold, it is determined to be the second turbidity range. The control unit controls the coagulant dosing submodule to keep the dosing amount corresponding to the current organic load range unchanged, and controls the cross-flow control module to run at the second cross-flow velocity. S23. When the influent turbidity is greater than the fourth threshold, it is determined to be in the third turbidity range. The control unit controls the coagulant dosing submodule to increase the second ratio based on the dosing amount corresponding to the current organic load range, and controls the cross-flow control module to operate at the third cross-flow velocity.

[0014] Specifically, S3 includes: S31. When the transmembrane pressure difference of ultrafiltration is less than or equal to the fifth threshold, it is determined to be the first pressure difference interval. The control unit controls the cross-flow control module to keep the cross-flow velocity corresponding to the current organic load interval unchanged, and controls the pulse component to keep the pulse mode corresponding to the current organic load interval unchanged. S32. When the fifth threshold < ultrafiltration transmembrane pressure difference ≤ the sixth threshold, it is determined to be the second pressure difference range. The control unit controls the cross-flow control module to increase the first flow rate increment based on the cross-flow velocity corresponding to the current organic load range, and controls the pulse component to switch to continuous operation mode and increase the first voltage increment. S33. When the transmembrane pressure difference is greater than the sixth threshold, it is determined to be the third pressure difference range. The control unit controls the cross-flow control module to increase the cross-flow velocity to the upper limit value, controls the pulse component to run continuously at the highest voltage, and outputs a chemical cleaning reminder signal.

[0015] The integrated photocatalysis-coagulation-ultrafiltration short-process water treatment device and control method of the present invention have the following advantages compared with the prior art: The photocatalytic-coagulation-ultrafiltration integrated short-process water treatment device provided by this invention utilizes a 365nm ultraviolet LED and a TiO2 / rGO catalytic mesh installed on the upper part of the shell. Wastewater undergoes photocatalytic pre-oxidation to remove UV radiation. 254 The characterized organic matter is broken down into smaller molecules, solving the problem of weak removal capacity of conventional coagulation for such organic matter, and reducing the organic pollution load of subsequent ultrafiltration membranes from the source. Simultaneously, the stirring submodule extends below the catalytic component through the dosing port of the catalytic component and coagulant dosing submodule, allowing the wastewater to immediately contact and rapidly disperse with the coagulant after photocatalytic pre-oxidation, avoiding time delays and intermediate transfer losses between photocatalysis and coagulation, and ensuring the compactness and continuity of the process chain. By setting a pulse component on the side of the hollow fiber ultrafiltration membrane component, the pulsed electric field effectively… This invention inhibits the adhesion of colloidal particles and microorganisms to the surface and surrounding areas of the hollow fiber ultrafiltration membrane, slows down the rise of transmembrane pressure difference, and extends the chemical cleaning cycle and service life of the hollow fiber ultrafiltration membrane module. The invention integrates the above-mentioned photocatalytic pre-oxidation module, coagulation and flocculation module and ultrafiltration module into the same housing from top to bottom, forming an integrated short-process structure. It eliminates the sedimentation tank and intermediate filter tank in the traditional process, greatly reduces the equipment footprint, and lowers infrastructure investment and operation and maintenance costs. It is especially suitable for scenarios with limited land use, such as the upgrading and renovation of small urban water plants and centralized water supply in rural areas.

[0016] The method for controlling the integrated short-process water treatment device of photocatalysis-coagulation-ultrafiltration provided by this invention involves real-time acquisition of UV data from the influent. 254 It compares the light intensity of the light source with preset first and second thresholds, and automatically determines the light intensity of the light source, the baseline dosage of the coagulant, and the pulse mode of the pulse component based on the comparison results. This achieves adaptive matching of ultraviolet light intensity, coagulant dosage, and pulse electric field parameters with the organic load of the influent, avoiding the lag and inaccuracy of manual experience-based control, and solving the technical problem of the lack of active organic matter degradation capability in existing processes; through UV... 254 Based on graded control, the influent turbidity is further collected and compared with preset third and fourth thresholds. The coagulant dosage is automatically adjusted according to the comparison results, and a cross-flow velocity is set. This achieves dynamic adjustment of the coagulant dosage based on the influent suspended solids concentration, ensuring coagulation effect while avoiding waste and increased membrane fouling caused by excessive reagent dosage. Through UV... 254Based on graded regulation and turbidity correction, the transmembrane pressure difference is further collected and compared with the preset fifth and sixth thresholds. According to the comparison results, the crossflow velocity and pulse mode are automatically corrected, realizing the adaptive adjustment of membrane surface scouring intensity and pulse electric field parameters according to the membrane fouling state. This effectively delays the occurrence of irreversible membrane fouling, significantly reduces the frequency of chemical cleaning, and extends the continuous operation cycle of the membrane module. Through the above three-level progressive regulation method, the device can achieve unattended automated operation under seasonal water quality changes, greatly reducing manual dependence and operation and maintenance difficulty. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the integrated short-process water treatment device for photocatalysis-coagulation-ultrafiltration provided in an embodiment of the present invention. Figure 2 The present invention provides a control method for a short-process water treatment device based on an integrated photocatalysis-coagulation-ultrafiltration system.

[0018] In the diagram, 1 is the inlet; 2 is the shell; 3 is the photocatalytic pre-oxidation module; 31 is the light source; 32 is the catalytic component; 4 is the coagulation and flocculation module; 41 is the coagulant dosing submodule; 411 is the reagent storage tank; 412 is the precision metering pump; 42 is the stirring submodule; 420 is the first vertical stirring shaft; 421 is the high-speed stirring paddle; 422 is the frame-type low-speed stirring paddle; 423 is the second vertical stirring shaft; 43 is the pH electrode; 5 is the ultrafiltration module; 51 is the hollow fiber ultrafiltration membrane module; 52 is the pulse module; 6 is the linkage control module; 60 is the control unit; and 61 is the inlet UV filter. 254 Acquisition unit; 62 is the influent turbidity acquisition unit; 63 is the ultrafiltration transmembrane pressure difference acquisition unit; 631 is the pressure transmitter at the straight-through short pipe 8; 632 is the pressure transmitter at the product water outlet 9; 7 is the cross-flow control module; 71 is the cross-flow circulation pump; 8 is the straight-through short pipe; 9 is the product water outlet; 10 is the sewage outlet; 11 is the quartz sleeve; 12 is the first perforated flow guide baffle; 13 is the second perforated flow guide baffle; 14 is the solid sealed partition baffle. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0020] One embodiment of the present invention provides a short-process water treatment device integrating photocatalysis-coagulation-ultrafiltration, such as... Figure 1As shown, it includes: a shell 2 with a water inlet 1 at the top, and a photocatalytic pre-oxidation module 3, a coagulation and flocculation module 4 and an ultrafiltration module 5 arranged sequentially from top to bottom inside the shell 2; The photocatalytic pre-oxidation module 3 includes a light source 31 and a catalytic component 32. The light source 31 is disposed on the inner wall of the housing 2, and the catalytic component 32 is fixed inside the housing 2. It is used to degrade organic matter in wastewater entering through the inlet 1 under the catalysis of the light source 31. The organic matter is UV-sensitive. 254 Characterized organic matter; In this embodiment of the invention, the organic material is UV. 254 Characterized organic compounds; using UV... 254 As a detection indicator, it has the advantages of fast detection speed and low cost, and is convenient for real-time monitoring; and UV 254 The characterized organic matter specifically refers to macromolecular organic matter with a particle size of 0.5 nm to 5 nm. This type of macromolecular organic matter causes severe membrane fouling and is difficult to remove effectively by conventional coagulation processes. Furthermore, its size is similar to that of ultrafiltration membrane pores, making it highly susceptible to adsorption onto the membrane surface or clogging of the pores. Therefore, UV... 254 Characterizing this type of organic matter can not only sensitively reflect the load of macromolecular organic pollutants in water, but also provide effective control targets for subsequent photocatalytic pre-oxidation and coagulation processes.

[0021] Specifically, the catalytic component 32 is a carrier network with photocatalytic material on its surface; The photocatalytic material is a composite material formed by a metal oxide, metal sulfide, or metal nitride and a carbon-based material; the support mesh is a metal mesh, a carbon-based mesh, or a glass fiber mesh.

[0022] For example, the photocatalytic material in this embodiment of the invention is a TiO2 / rGO composite sol, and the supporting mesh is an industrial pure titanium mesh; wherein the preparation method of the TiO2 / rGO catalytic mesh is as follows: S1. Cut the titanium mesh into a circular sample that fits the inner diameter of the shell 2. Clean it with acetone, anhydrous ethanol and deionized water at room temperature for 15 minutes each to remove surface oil, oxide layer and impurities. Then place it in a vacuum oven at 60℃ for 1 hour to dry. S2. In this embodiment of the invention, tetrabutyl titanate is preferably used as the TiO2 precursor. In practical applications, it can also be a titanium source precursor such as tetraisopropyl titanate, titanium tetrachloride, or titanium sulfate. 10 mL of tetrabutyl titanate is measured and slowly added dropwise to 40 mL of anhydrous ethanol. The mixture is magnetically stirred for 20 min to ensure uniform mixing. A complexing stabilizer is added to the stirred solution. In this embodiment of the invention, glacial acetic acid is preferably used as the complexing stabilizer. In practical applications, it can also be a similar complexing stabilizer such as acetylacetone, triethanolamine, or ammonia. 5 mL of glacial acetic acid is added to the stirred solution and the mixture is stirred continuously until the solution is completely transparent. Then, 20 mL of rGO (Reduced Graphene Oxide) dispersion with a concentration of 2 mg / mL is added, and the mixture is ultrasonically dispersed for 2 h under ice-water bath conditions to obtain a uniform and stable TiO2 / rGO composite sol. S3. Vertically and completely immerse the pretreated titanium mesh from S1 into the TiO2 / rGO composite sol, let it stand for 10 seconds, and then pull it upwards at a uniform speed of 0.5 cm / s. After natural surface drying at room temperature, repeat the immersion coating 3 times according to the same parameters to ensure that the coating thickness is uniform. After the immersion coating is completed, place it in a 60℃ oven for constant temperature drying for 30 minutes, and then transfer it to a UV curing box for curing with 365nm UV irradiation for 30 minutes to ensure that the catalyst layer is firmly bonded to the titanium mesh substrate. After cooling, set aside for subsequent assembly or replacement.

[0023] In this embodiment of the invention, the light source 31 preferably employs a 365nm ultraviolet LED array. The ultraviolet light, in synergy with the photocatalytic material, breaks down and opens the chains of large molecules of humic acid and algal metabolites in the water, converting them into easily coagulated small molecules, thus reducing the organic pollution load on the membrane at the source. Furthermore, the 365nm wavelength ultraviolet light is in the strong absorption region of TiO2, which can excite TiO2 to generate photogenerated electron-hole pairs required for the photocatalytic reaction. rGO can act as a highly efficient electron capture acceptor and electron transport channel, rapidly transferring and separating photogenerated electrons, effectively suppressing the recombination of electron-hole pairs, allowing more holes to participate in the oxidation reaction, significantly improving photocatalytic efficiency. Simultaneously, the LED supports instant on / off switching, has adjustable light intensity, is small in size, and has a long lifespan. Moreover, the ultraviolet LED array is encapsulated in a quartz sleeve 11, which isolates it from the water flow, ensuring long-term stable operation of the ultraviolet LED in complex aquatic environments. This embodiment of the invention does not impose specific limitations on the light source 31, as long as it can excite the photocatalytic reaction and is well-matched with the photocatalytic material. The ultraviolet LED array is also connected to the linkage control module 6 via a signal line. In operation, the linkage control module 6 adjusts the signal according to the UV output at the inlet 1. 254 Real-time UV data of influent collected by the acquisition unit 254 The signal outputs a light intensity control command to the driver power supply of the ultraviolet LED.

[0024] The coagulation and flocculation module 4 includes a coagulant dosing submodule 41 and a stirring submodule 42; the dosing port of the coagulant dosing submodule 41 extends into the bottom of the catalytic component 32; the stirring submodule 42 passes through the catalytic component 32 and is used to disperse the coagulant in the wastewater after the organic matter has been degraded.

[0025] In this embodiment of the invention, the coagulant dosing submodule 41 is a reagent storage tank 411 and a precision metering pump 412 connected to the reagent storage tank 411. The precision metering pump 412 can control the amount of reagent added. In this embodiment of the invention, the coagulant is preferably PAC (Polyaluminium Chloride). In practical applications, it can also be inorganic coagulants such as aluminum sulfate, ferrous sulfate, and polyferric sulfate.

[0026] In this embodiment of the invention, the actual PAC dosage parameters were determined based on the results of beaker experiments: 1000 mL of representative raw water from the site was placed in a standard beaker of a six-unit electric stirrer; PAC dosage gradients of 5 mg / L, 8 mg / L, 12 mg / L, 15 mg / L, and 20 mg / L were set, with three parallel samples per group; the actual operating conditions of the device were simulated: rapid stirring at 300 rpm for 60 s, flocculation stirring at 180 rpm for 5 min; static sedimentation for 30 min, and collection of the supernatant 2 cm below the liquid surface; turbidity and UV of each group were measured. 254 And DOC (Dissolved Organic Carbon), and calculate their respective removal rates; simultaneously satisfying UV... 254 The actual addition parameters are those corresponding to the highest removal rate, floc fractal dimension stable at 1.6-1.8, and pH of the system stable at 6.5-7.8 after coagulation reaction. These actual addition parameters are entered into the linkage control module 6 as the benchmark for on-site operation. In this embodiment of the invention, the actual addition parameters obtained are 7 mg / L-12 mg / L.

[0027] In this embodiment of the invention, the coagulation and flocculation module 4 is also provided with a pH electrode 43, which is connected to the linkage control module 6 via a signal line, and is used to collect the acidity and alkalinity signal of the water after photocatalytic pre-oxidation.

[0028] In this embodiment of the invention, the stirring submodule 42 includes a first vertical stirring shaft 420 and a high-speed stirring paddle 421 disposed on the first vertical stirring shaft 420. The first vertical stirring shaft 420 is controlled by a first drive motor. The first vertical stirring shaft 420, the high-speed stirring paddle 421, and the first drive motor are disposed in a rapid mixing zone. The first vertical stirring shaft 420 extends from the top of the cavity of the rapid mixing zone. The high-speed stirring paddle 421 is used for rapid stirring, so that the coagulant is rapidly dispersed in the wastewater after the organic matter has been degraded. The submodule also includes a second vertical stirring shaft 423 and a frame-type low-speed stirring paddle 422 disposed on the second vertical stirring shaft. The second vertical stirring shaft 423 is controlled by a second drive motor. The second vertical stirring shaft 423, the frame-type low-speed stirring paddle 422, and the second drive motor are disposed in a flocculation growth zone. The second vertical stirring shaft 423 extends from the top of the cavity of the flocculation growth zone. The frame-type low-speed stirring paddle 422 is used for flocculation stirring, further forming a stable floc with a dense structure that is not easily penetrated by the membrane pores.

[0029] The first and second drive motors mentioned above are independently frequency-controlled and are connected to the linkage control module 6 via signal lines. The control unit 60 of the linkage control module 6 adjusts the influent turbidity and influent UV based on the influent turbidity and UV. 254 The system outputs speed control commands to the first drive motor and the second drive motor respectively, based on the pH signal, to adjust the different stirring speeds required for the rapid mixing and flocculation processes. This ensures that the speed of the high-speed stirring paddle 421 meets the high-shear destabilization requirements of the mixing stage, while the speed of the frame-type low-speed stirring paddle 422 meets the differentiated hydraulic conditions for low-shear floc growth during the flocculation stage.

[0030] In this embodiment of the invention, a first perforated flow guide baffle 12 is provided between the rapid mixing zone and the catalytic component 32. This baffle evenly distributes the effluent flowing through the catalytic component 32 into the rapid mixing zone, while simultaneously blocking upper-layer ultraviolet light from penetrating downwards, preventing ultraviolet light from irradiating the rapid mixing zone and thus preventing the coagulant from photodegrading or becoming ineffective under ultraviolet light. A second perforated flow guide baffle 13 is provided between the rapid mixing zone and the flocculation growth zone. This baffle eliminates water flow eddies in the rapid mixing zone, provides stable flow conditions for floc growth, and simultaneously blocks residual ultraviolet light, protecting the flocs from harmful radiation. The influence of light irradiation; a solid sealed partition plate 14 is set between the flocculation growth zone and the hollow fiber ultrafiltration membrane module 51. The solid sealed partition plate 14 is a non-porous whole plate structure with a straight short pipe 8 at its center. The effluent from the flocculation growth zone enters the ultrafiltration module 5 only through the connecting short pipe 8. The solid sealed partition plate 14 is used to completely isolate the stirring disturbance of the flocculation growth zone from the hydraulic conditions of the ultrafiltration module 5, ensuring the stability and accuracy of the pressure measurement at the inlet of the ultrafiltration module 5, and avoiding the interference of pressure fluctuations caused by stirring in the flocculation zone with the subsequent transmembrane pressure difference acquisition.

[0031] The ultrafiltration module 5 is detachably connected to the inner wall of the housing 2. The ultrafiltration module 5 includes a hollow fiber ultrafiltration membrane assembly 51 and a pulse assembly 52. ​​The surface of the hollow fiber ultrafiltration membrane assembly 51 is provided with a hydrophilic modified layer for filtering wastewater passing through the coagulation and flocculation module 4. The pulse assembly 52 is located inside the housing 2 and is disposed on the side of the hollow fiber ultrafiltration membrane assembly 51 for removing contaminants adhering to the hollow fiber ultrafiltration membrane assembly 51.

[0032] Specifically, the hollow fiber ultrafiltration membrane module 51 is made of one of polyethersulfone, polyvinylidene fluoride, polyacrylonitrile, and polyvinyl chloride; a hydrophilic modification layer is loaded on the outer surface of the hollow fiber ultrafiltration membrane. The hydrophilic modification layer is composed of inorganic nanomaterials and carbon-based materials. The overall water contact angle of this composite is less than 90°, and it has hydrophilic properties.

[0033] In this embodiment of the invention, the hollow fiber ultrafiltration membrane module 51 preferably uses a commercially available polyethersulfone hollow fiber ultrafiltration base membrane; the hydrophilic modification layer preferably uses a TiO2 / GO modification solution, which, while performing hydrophilic modification, also achieves photocatalytic self-cleaning and improves photocatalytic efficiency; the specific preparation method is as follows: S1. Take a commercial polyethersulfone hollow fiber ultrafiltration membrane, and use deionized water to ultrasonically clean the commercial polyethersulfone hollow fiber ultrafiltration membrane at room temperature for 20 minutes to remove the factory protective agent and surface dust; rinse 3 times with anhydrous ethanol, and dry in a vacuum oven at 40℃ for 1 hour for later use. S2. Place 100 mL of TiO2 hydrosol in a stirring container, and slowly add 10 mL of 2 mg / mL GO (Graphene Oxide) dispersion while continuously stirring. Mix well, and then add a dispersion stabilizer. In this embodiment of the invention, the dispersion stabilizer is preferably PVP (Polyvinylpyrrolidone). In practical applications, it can also be a colloidal dispersion stabilizer such as polyethylene glycol, hexadecyltrimethylammonium bromide, or sodium dodecylbenzenesulfonate. Add 0.5 g of PVP to the mixed solution of TiO2 hydrosol and graphene oxide dispersion, and stir magnetically at room temperature for 1 h until the system is free of agglomeration and completely homogeneous to obtain the modified solution.

[0034] S3. The pretreated polyethersulfone hollow fiber ultrafiltration membrane is vertically fixed on the dip-coating support and immersed in the modification solution at a uniform speed of 0.5 cm / s. After wetting for 10 seconds, it is slowly pulled out. Each layer is air-dried at room temperature for 30 minutes. The dip-coating is repeated 3 times to ensure that the modification solution evenly covers the membrane surface and the inner wall of the micropores. After coating, the membrane is irradiated with 365 nm ultraviolet light for 20 minutes to achieve cross-linking and curing of the interface between the modification solution and the polyethersulfone hollow fiber ultrafiltration membrane. After rinsing with deionized water to remove free TiO2 and GO nanoparticles, the membrane is dried at 40°C and assembled into a hollow fiber ultrafiltration membrane module 51 with a hydrophilic modification layer on the surface for later use.

[0035] In this embodiment of the invention, the pulse component 52 preferably adopts a titanium-plated ruthenium pulse electrode. This electrode applies a low-voltage alternating electric field to change the surface potential of colloids and microbial particles in the water, inhibiting pollutants from adhering to the surface of the hollow fiber ultrafiltration membrane. It works synergistically with the hydrophilic modification layer to construct a dual anti-pollution system of material modification and electric field desorption. In practical applications, the electric field desorption of the ultrafiltration module can also use conductive electrodes with other coatings as pulse electrodes, such as titanium-plated iridium dioxide electrodes, titanium-plated lead oxide electrodes, graphite electrodes, copper electrodes, etc. Among them, copper electrodes are only suitable for short-term operation in neutral, low-corrosion water bodies. In addition to electrode-type pulse components, plasma pulse oxidation components that directly apply pulse discharge to the water body can also be used as pretreatment units to achieve synergistic degradation of pollutants.

[0036] The hollow fiber ultrafiltration membrane assembly 51, pulse assembly 52, stirring sub-module 42 and catalytic assembly 32 with hydrophilic modified layers on their surfaces are sequentially placed into the housing 2 to complete the assembly.

[0037] Furthermore, it also includes a linkage control module 6, which includes an influent UV filter. 254 Acquisition unit 61 and influent UV 254 The acquisition unit 61 is connected to the control unit 60; UV inlet water 254 The collection unit 61 is located at the water inlet 1 of the housing 2; The control unit 60 is also connected to the light source 31, the coagulant dosing submodule 41, and the pulse assembly 52. ​​The control unit 60 is used to adjust the UV of the influent. 254 The signals acquired by the acquisition unit 61 control the light intensity of the light source 31, the amount of coagulant added by the coagulant addition submodule 41, and the pulse mode of the pulse component 52.

[0038] In an embodiment of the present invention, the influent UV... 254 The acquisition unit 61 is located at the lower end of the water inlet 1 and is connected to the linkage control module 6 via a signal line. The control unit 60 of the linkage control module 6 receives the incoming water UV data. 254 The signal sends control commands to the light source 31, the coagulant dosing submodule 41, and the pulse component 52.

[0039] Furthermore, the linkage control module 6 also includes an influent turbidity acquisition unit 62 connected to the control unit 60; The inlet turbidity collection unit 62 is installed at the inlet 1 of the housing 2; The control unit 60 is also connected to the cross-flow control module 7, which is located outside the housing 2 and connected to the upper and lower ends of the hollow fiber ultrafiltration membrane assembly 51, and is used to regulate the cross-flow rate of the hollow fiber ultrafiltration membrane assembly 51. The control unit 60 is also used to adjust the dosage and crossflow velocity of the coagulant dosing submodule 41 based on the signal collected by the influent turbidity acquisition unit 62.

[0040] In this embodiment of the invention, the influent turbidity acquisition unit 62 is disposed at the influent UV. 254 Below the collection unit 61, the raw water first flows through the inlet UV. 254 The water flows from the collection unit 61 to the influent turbidity collection unit 62 to complete the water quality parameter collection. The influent turbidity collection unit 62 is connected to the linkage control module 6 via a signal line. The control unit 60 of the linkage control module 6 sends control commands to the coagulant dosing submodule 41 and the cross-flow control module 7 based on the received influent turbidity signal.

[0041] In this embodiment of the invention, the cross-flow control module 7 is a variable frequency cross-flow circulation pump 71. The input end of the cross-flow circulation pump 71 is connected to the lower end of the hollow fiber ultrafiltration membrane module 51, and the output end of the cross-flow circulation pump 71 is connected to the straight short pipe 8 at the upper end of the hollow fiber ultrafiltration membrane module 51. The control module can dynamically adjust the cross-flow velocity of the hollow fiber ultrafiltration membrane module 51 by controlling the cross-flow circulation pump 71. In practical applications, the control module increases the output frequency of the frequency converter, thereby increasing the rotation speed and circulation flow of the cross-flow circulation pump 71 and thus increasing the cross-flow velocity of the hollow fiber ultrafiltration membrane module 51. Conversely, the control module decreases the output frequency of the frequency converter, thereby decreasing the rotation speed and circulation flow of the cross-flow circulation pump 71 and thus decreasing the cross-flow velocity of the hollow fiber ultrafiltration membrane module 51.

[0042] Furthermore, the linkage control module 6 also includes an ultrafiltration transmembrane pressure differential acquisition unit 63 connected to the control unit 60; The ultrafiltration transmembrane pressure difference acquisition unit 63 is located at the upper end of the hollow fiber ultrafiltration membrane module 51 and at the product water outlet 9 of the shell 2; The control unit 60 is also used to adjust the crossflow velocity and the pulse mode of the pulse component 52 based on the signal acquired by the ultrafiltration transmembrane pressure difference acquisition unit 63.

[0043] In this embodiment of the invention, the ultrafiltration transmembrane pressure difference acquisition unit 63 includes two pressure transmitters, respectively located at the straight-through short pipe 8 at the upper end of the hollow fiber ultrafiltration membrane module 51 and at the product water port 9 of the housing 2. The pressure transmitter 631 at the straight-through short pipe 8 is used to acquire the pressure signal at the inlet end of the hollow fiber ultrafiltration membrane module 51; the pressure transmitter 632 at the product water port 9 is used to acquire the pressure signal at the product water end of the hollow fiber ultrafiltration membrane module 51. These two pressure transmitters are respectively connected to the control unit 60 of the linkage control module 6 via signal lines. In operation, the pressure transmitters convert the real-time sensed physical pressure signal into an electrical signal and transmit it to the control unit 60; the control unit 60 calculates the real-time transmembrane pressure difference based on the received electrical signal.

[0044] In this embodiment of the invention, the reference input of the linkage control module 6 is set according to the following parameters: water sample is taken and allowed to stand for 10 minutes, then the supernatant is collected, and the turbidity is measured sequentially using a portable turbidimeter, and the UV is measured using an ultraviolet spectrophotometer and a 1cm quartz cuvette. 254 Acidity was determined in situ using a laboratory pH meter; alkalinity was determined using acid-base titration; and Ca²⁺ was determined using atomic absorption spectrophotometry. + Concentration and Mg² + The concentration and DOC are detected using a total organic carbon analyzer. The above detection data serve as the reference input for the linkage control module 6. The linkage control module 6 adaptively adjusts each operating parameter according to the reference input to achieve unattended automated operation.

[0045] In practical applications, the aforementioned integrated short-process water treatment device combining photocatalysis, coagulation, and ultrafiltration also needs to be cleaned. This invention also provides a membrane resistance separation and graded cleaning operation process, as detailed below: S1. Resistance Measurement: The initial reference flux was measured by introducing 20°C clean water into the device under no-load conditions. The baseline flux control range is During normal operation, the transmembrane pressure difference is recorded in real time, and a series filtration resistance model is used to decompose the resistance into four types: inherent membrane resistance. Concentration polarization resistance Reversible filter cake resistance Irreversible hole resistance Among them, the inherent resistance of the membrane The stable value is (1.2-1.8)×10¹²m - ¹; Concentration polarization resistance under normal operating conditions Reversible filter cake resistance accounts for 10%-20% of the total resistance. Irreversible hole resistance accounts for 20%-40% of the total resistance. It accounts for less than 15% of the total resistance; when the irreversible orifice resistance If the irreversible fouling is 15% or more of the total resistance, or the flux after backwashing only recovers to 85% or less of the baseline flux, or the transmembrane pressure difference after backwashing increases by ≥0.05MPa from the baseline, it is judged to be too high. S2. The parameters for routine periodic air-water backwashing are as follows: air flushing intensity 40L / ( ), lasting 1 minute; water flushing intensity 15L / ( ), lasting 2 minutes; S3. When irreversible contamination is high, start online chemical cleaning: prepare a compound cleaning solution of 0.1wt% sodium hypochlorite and 0.05wt% citric acid, clean in a closed loop for 20 minutes, then soak statically for 10 minutes; rinse with clean water until the pH of the influent and effluent is close to neutral. S4. Restart the flux measurement, requiring a flux recovery rate of ≥95%. If the flux recovery rate is less than 95%, repeat the above-mentioned graded cleaning steps.

[0046] On the other hand, embodiments of the present invention also provide a control method for a short-process water treatment device based on an integrated photocatalysis-coagulation-ultrafiltration system, including: S1, Collect UV data from incoming water 254 UV inlet water 254 Compared with the preset first threshold and second threshold, the first threshold is less than the second threshold; based on the comparison result, the light intensity of the light source 31, the reference dosage of the coagulant dosing submodule 41 and the pulse mode of the pulse component 52 are determined. Specifically, the incoming water UV 254 The comparison with preset first and second thresholds includes: S11, When the UV inlet water is present 254 When the load is ≤ the first threshold, it is determined to be the first organic matter load range. The control unit 60 controls the light source 31 to operate at the first light intensity, the coagulant dosing submodule 41 to operate at the first dosing amount, and the pulse component 52 to operate in the first pulse mode. S12, When the first threshold is less than the influent UV 254 When the load is ≤ the second threshold, it is determined to be in the second organic matter load range. The control unit 60 controls the light source 31 to operate at the second light intensity, the coagulant dosing submodule 41 to operate at the second dosing amount, and the pulse component 52 to operate in the second pulse mode. The second light intensity is greater than the first light intensity, and the second dosing amount is greater than the first dosing amount. S13, When the UV inlet water is present 254 When the load exceeds the second threshold, it is determined to be in the third organic load range. The control unit 60 controls the light source 31 to operate at the third light intensity, the coagulant dosing submodule 41 to operate at the third dosing amount, and the pulse component 52 to operate in the third pulse mode. The third light intensity is greater than the second light intensity, and the third dosing amount is greater than the second dosing amount. In this embodiment of the invention, the first threshold is 0.08 cm. - ¹, the second threshold mentioned above is 0.15cm - ¹; When the measured UV 254 ≤0.08cm - At time ¹, the low organic load range is reached; at this time, the control unit 60 controls the light intensity of the 365nm ultraviolet LED to operate at a light intensity of 10mW / cm²-15mW / cm²; the PAC dosage is reduced to 5mg / L-7mg / L based on the actual dosage parameters of 7mg / L-12mg / L; the titanium-plated ruthenium pulse electrode operates in the first pulse mode: the pulse electric field cycles intermittently for 3 minutes and stops for 5 minutes, with a voltage of 5V-7V; When 0.08cm - ¹<UV 254≤0.15cm - At time ¹, the organic matter load range is reached; at this time, the control unit 60 controls the light intensity of the 365nm ultraviolet LED to operate at a light intensity of 15mW / cm²-25mW / cm²; the PAC dosage remains unchanged at the actual dosage parameters of 7mg / L-12mg / L; the titanium-plated ruthenium pulse electrode operates in the second pulse mode: the pulse electric field cycles intermittently for 4 minutes and stops for 3 minutes, with a voltage of 7V-10V; When UV 254 >0.15cm - ¹ During the high organic load range, the control unit 60 controls the light intensity of the 365nm ultraviolet LED to operate at the highest level of 25mW / cm²-35mW / cm²; the PAC dosage is increased to 12mg / L-20mg / L based on the actual dosage parameters of 7mg / L-12mg / L; the titanium-plated ruthenium pulse electrode operates in the third pulse mode: the pulse electric field is continuously turned on and off, and the intermittent shutdown is canceled, with a voltage of 10V-15V.

[0047] S2. Collect the influent turbidity and compare it with the preset third and fourth thresholds. If the third threshold is less than the fourth threshold, adjust the current baseline dosage and set the current crossflow velocity based on the comparison results. Specifically, the influent turbidity is compared with preset third and fourth thresholds, including: S21. When the influent turbidity is less than or equal to the third threshold, it is determined to be the first turbidity range. The control unit 60 controls the coagulant dosing submodule 41 to reduce the first ratio based on the dosing amount corresponding to the current organic load range, and controls the cross-flow control module 7 to operate at the first cross-flow velocity. S22. When the third threshold < influent turbidity ≤ fourth threshold, it is determined to be the second turbidity range. The control unit 60 controls the coagulant dosing submodule 41 to keep the dosing amount corresponding to the current organic load range unchanged, and controls the cross-flow control module 7 to run at the second cross-flow velocity. S23. When the influent turbidity is greater than the fourth threshold, it is determined to be in the third turbidity range. The control unit 60 controls the coagulant dosing submodule 41 to increase the second ratio based on the dosing amount corresponding to the current organic load range, and controls the cross-flow control module 7 to operate at the third cross-flow velocity. In this embodiment of the invention, the third threshold is 5 NTU and the fourth threshold is 15 NTU. When the influent turbidity is ≤5 NTU, it is in the low turbidity range. The control unit 60 controls the PAC dosage to be reduced by 10% based on the dosage corresponding to the current organic load range. The cross-flow circulation pump 71 is controlled to maintain the cross-flow velocity at a low level of 0.6 m / s-0.8 m / s. When 5 NTU < influent turbidity ≤ 15 NTU, it is in the medium turbidity range; the control unit 60 controls the PAC dosage to maintain the dosage corresponding to the current organic load range; and controls the cross-flow circulation pump 71 to maintain the cross-flow velocity at the standard setting of 0.8 m / s-1.2 m / s. When the influent turbidity is >15 NTU, it is in the high turbidity range; the control unit 60 controls the PAC dosage to be increased by 20% based on the dosage corresponding to the current organic load range; the cross-flow circulation pump 71 is controlled to increase the cross-flow velocity to a high level of 1.2 m / s-1.8 m / s to enhance the hydraulic shear scouring of the membrane surface.

[0048] S3. Collect the ultrafiltration transmembrane pressure difference of the hollow fiber ultrafiltration membrane module 51, compare the ultrafiltration transmembrane pressure difference with the preset fifth threshold and sixth threshold, and the fifth threshold is less than the sixth threshold; based on the comparison result, correct the current crossflow velocity and pulse mode.

[0049] Specifically, the ultrafiltration transmembrane pressure difference is compared with preset fifth and sixth thresholds, including: S31. When the ultrafiltration transmembrane pressure difference is less than or equal to the fifth threshold, it is determined to be the first pressure difference interval. The control unit 60 controls the cross-flow control module 7 to keep the cross-flow velocity corresponding to the current organic load interval unchanged, and controls the pulse component 52 to keep the pulse mode corresponding to the current organic load interval unchanged. S32. When the fifth threshold < ultrafiltration transmembrane pressure difference ≤ the sixth threshold, it is determined to be the second pressure difference range. The control unit 60 controls the cross-flow control module 7 to increase the first flow rate increment based on the cross-flow velocity corresponding to the current organic load range, and controls the pulse component 52 to switch to continuous operation mode and increase the first voltage increment. S33. When the transmembrane pressure difference is greater than the sixth threshold, it is determined to be the third pressure difference range. The control unit 60 controls the cross-flow control module 7 to increase the cross-flow velocity to the upper limit value, controls the pulse component 52 to run continuously at the highest voltage, and outputs a chemical cleaning reminder signal.

[0050] In this embodiment of the invention, the transmembrane pressure difference of ultrafiltration is based on the initial pressure difference of the cleaned hollow fiber ultrafiltration membrane module 51, which is 0.03MPa-0.05MPa. The fifth threshold is determined to be 0.01MPa (an increase of less than 50% from the baseline), and the sixth threshold is determined to be 0.15MPa (an increase of less than 200% from the baseline). When the transmembrane pressure difference of ultrafiltration is <0.01MPa, it is in the normal range. The control unit 60 controls the cross-flow circulation pump 71 to keep the cross-flow velocity constant according to the current organic load range; and controls the titanium-plated ruthenium pulse electrode to keep the pulse mode constant according to the current organic load range. When 0.01MPa < ultrafiltration transmembrane pressure difference ≤ 0.15MPa, it is a warning range. Control unit 60 controls cross-flow circulation pump 71 to increase the cross-flow velocity by 0.3m / s-0.5m / s based on the cross-flow velocity corresponding to the current organic load range; controls the titanium-plated ruthenium pulse electrode to switch to continuous operation mode and increases the voltage by 2V-3V; and simultaneously shortens the air-water backwashing cycle. When the transmembrane pressure difference of ultrafiltration is >0.15MPa, it is in the heavily polluted range. The control unit 60 controls the cross-flow circulation pump 71 to increase the cross-flow velocity to the upper limit of 1.8m / s; controls the titanium-plated ruthenium pulse electrode to run continuously at the highest voltage of 15V, and outputs a chemical cleaning reminder signal.

[0051] This invention also provides a method of using an integrated photocatalysis-coagulation-ultrafiltration short-process water treatment device, comprising: S1. Pre-start inspection: All pipeline seals, electrode wiring, coagulant level, and all sensors of the linkage control module are calibrated to be normal. S2. Open the valve of inlet 1 to allow water to enter at a low speed and purge the air from inside the device. S3. Start the ultraviolet LED and preheat for 3 minutes, then turn on the stirring submodule 42; S4, the linkage control module 6 retrieves the actual addition parameters of the coagulant and starts the precision metering pump 412 for automatic addition; S5. Raw water first passes through photocatalytic pre-oxidation module 3, where large organic molecules are degraded through the synergistic effect of ultraviolet-catalysis. It then enters coagulation and flocculation module 4, where it is first rapidly mixed with coagulant and then forms stable and dense flocs. The floc-containing water does not undergo sedimentation and directly enters ultrafiltration module 5 to complete solid-liquid separation. Clean water is continuously produced from the product outlet 9, and the pollutants on the membrane surface are discharged from the drain outlet 10 under the dual action of its own photocatalytic self-cleaning and pulsed electric field. S6. During daily operation, the linkage control module 6 adjusts the input UV based on the water inlet. 254 The light intensity of the ultraviolet LED, the dosage of PAC, the cross-flow velocity and the pulse mode are adaptively adjusted based on the influent turbidity and the ultrafiltration transmembrane pressure difference. S7 and the linkage control module 6 automatically clean the device by monitoring the membrane resistance in real time.

[0052] Taking a typical rural slightly polluted raw water source as an example, the device and method described in this invention are verified as follows: The raw water quality parameters are as follows: turbidity is 12 NTU, UV... 254 It is 0.18cm - ¹, pH 7.5, water temperature 20℃; according to the beaker experiment method provided in the embodiments of the present invention, multiple PAC addition gradients were set up for coagulation optimization experiments, under UV... 254Under the constraints of achieving the highest removal rate, floc fractal dimension between 1.6 and 1.8, and a stable pH of 6.5 to 7.8 after coagulation, the actual PAC dosage was determined to be 7 mg / L. The raw water was fed into the device and operated continuously for 30 days. The operating parameters were as follows: 365nm ultraviolet light intensity 25mW / cm², high-speed stirring paddle 421 speed 300rpm, stirring time 50s, frame-type low-speed stirring paddle 422 speed 180rpm, stirring time 5min; cross-flow velocity 1.2m / s, and pulse electric field off.

[0053] After 30 days of continuous operation, samples were taken for testing. The turbidity of the effluent remained stable below 0.06 NTU, and the UV index of the effluent was [missing value]. 254 Reduced to 0.05cm - ¹The ultrafiltration transmembrane pressure difference rise is less than 12%, and no chemical cleaning is required within a 30-day operating cycle.

[0054] The above results indicate that the integrated short-process water treatment device and control method of photocatalysis-coagulation-ultrafiltration provided in this embodiment of the invention has a good treatment effect on conventional rural slightly polluted raw water, with stable effluent quality, low membrane fouling rate, and can achieve long-term stable operation.

[0055] The photocatalytic-coagulation-ultrafiltration integrated short-process water treatment device provided in this embodiment of the invention utilizes a 365nm ultraviolet LED and a TiO2 / rGO catalytic mesh installed on the upper part of the shell 2. Wastewater undergoes photocatalytic pre-oxidation to remove UV radiation. 254 The characterized organic matter is broken down into smaller molecules, solving the problem of weak removal capacity of conventional coagulation for such organic matter, and reducing the organic pollution load of subsequent ultrafiltration membranes from the source; at the same time, the stirring submodule 42 extends into the bottom of the catalytic component 32 through the dosing port of the coagulant dosing submodule 41, so that the wastewater can immediately contact the coagulant and disperse rapidly after photocatalytic pre-oxidation, avoiding the time delay and intermediate transfer loss between photocatalysis and coagulation, and ensuring the compactness and continuity of the process chain; by setting the pulse component 52 on the side of the hollow fiber ultrafiltration membrane component 51, the pulse electricity is used to The field effectively inhibits the adhesion of colloidal particles and microorganisms on and near the surface of the hollow fiber ultrafiltration membrane, slows down the rise of transmembrane pressure difference, and extends the chemical cleaning cycle and service life of the hollow fiber ultrafiltration membrane module 51. The present invention integrates the above-mentioned photocatalytic pre-oxidation module 3, coagulation and flocculation module 4 and ultrafiltration module 5 from top to bottom into the same housing 2 to form an integrated short-process structure, eliminating the sedimentation tank and intermediate filter tank in the traditional process, greatly reducing the equipment footprint, lowering infrastructure investment and operation and maintenance costs, and is especially suitable for scenarios with limited land use such as upgrading and renovation of small urban water plants and centralized water supply in rural areas.

[0056] The control method for the integrated short-process water treatment device of photocatalysis-coagulation-ultrafiltration provided in this embodiment of the invention involves real-time acquisition of UV data from the influent. 254 It compares the light intensity of the light source 31 with the preset first and second thresholds, and automatically determines the light intensity of the coagulant, the baseline dosage of the coagulant, and the pulse mode of the pulse component 52 based on the comparison results. This achieves adaptive matching of ultraviolet light intensity, coagulant dosage, and pulse electric field parameters with the organic load of the influent, avoiding the lag and inaccuracy of manual experience-based control, and solving the technical problem of the lack of active organic matter degradation capability in existing processes. 254 Based on graded control, the influent turbidity is further collected and compared with preset third and fourth thresholds. The coagulant dosage is automatically adjusted according to the comparison results, and a cross-flow velocity is set. This achieves dynamic adjustment of the coagulant dosage based on the influent suspended solids concentration, ensuring coagulation effect while avoiding waste and increased membrane fouling caused by excessive reagent dosage. Through UV... 254 Based on graded regulation and turbidity correction, the transmembrane pressure difference is further collected and compared with the preset fifth and sixth thresholds. According to the comparison results, the crossflow velocity and pulse mode are automatically corrected, realizing the adaptive adjustment of membrane surface scouring intensity and pulse electric field parameters according to the membrane fouling state. This effectively delays the occurrence of irreversible membrane fouling, significantly reduces the frequency of chemical cleaning, and extends the continuous operation cycle of the membrane module. Through the above three-level progressive regulation method, the device can achieve unattended automated operation under seasonal water quality changes, greatly reducing manual dependence and operation and maintenance difficulty.

[0057] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A control method for a short-process water treatment device based on photocatalysis-coagulation-ultrafiltration integrated system, characterized in that, The device includes: a shell with a water inlet at the top, and a photocatalytic pre-oxidation module, a coagulation and flocculation module and an ultrafiltration module arranged sequentially from top to bottom inside the shell; The photocatalytic pre-oxidation module includes a light source and a catalytic component. The light source is disposed on the inner wall of the housing, and the catalytic component is fixed inside the housing. It is used to degrade organic matter in wastewater entering through the inlet under the catalysis of the light source. The organic matter is UV-sensitive. 254 Characterized organic matter; The coagulation and flocculation module includes a coagulant dosing submodule and a stirring submodule; the dosing port of the coagulant dosing submodule extends below the catalytic component; the stirring submodule passes through the catalytic component and is used to disperse the coagulant in the wastewater after the organic matter has been degraded. The ultrafiltration module is detachably connected to the inner wall of the housing. The ultrafiltration module includes a hollow fiber ultrafiltration membrane assembly and a pulse assembly. The surface of the hollow fiber ultrafiltration membrane assembly is provided with a hydrophilic modification layer for filtering wastewater passing through the coagulation and flocculation module. The pulse assembly is located inside the housing and is disposed on the side of the hollow fiber ultrafiltration membrane assembly for removing contaminants adhering to the hollow fiber ultrafiltration membrane assembly. It also includes a linkage control module, which includes influent UV... 254 The acquisition unit and the influent UV 254 The control unit connected to the acquisition unit; the inlet UV 254 The acquisition unit is located at the water inlet of the housing; the control unit is also connected to the light source, the coagulant dosing submodule and the pulse assembly; The control unit is used to determine the influent UV. 254 The acquisition unit collects signals to regulate the light intensity of the light source, the dosage of the coagulant dosing submodule, and the pulse mode of the pulse component; the control unit is also connected to the cross-flow control module, which is located outside the housing and connected to the upper and lower ends of the hollow fiber ultrafiltration membrane component, and is used to regulate the cross-flow velocity of the hollow fiber ultrafiltration membrane component; The regulation method specifically includes: S11, when the inlet UV 254 When the load is ≤ the first threshold, it is determined to be the first organic load range. The control unit controls the light source to operate at the first light intensity, the coagulant dosing submodule to operate at the first dosing amount, and the pulse component to operate in the first pulse mode. S12, When the first threshold is less than the influent UV 254 When the light intensity is less than or equal to the second threshold, it is determined to be in the second organic matter load range. The control unit controls the light source to operate at the second light intensity, the coagulant dosing submodule to operate at the second dosing amount, and the pulse component to operate in the second pulse mode. The second light intensity is greater than the first light intensity, and the second dosing amount is greater than the first dosing amount. S13, when the inlet UV 254 When the threshold is greater than the second threshold, it is determined to be in the third organic matter load range. The control unit controls the light source to operate at the third light intensity, the coagulant dosing submodule to operate at the third dosing amount, and the pulse component to operate in the third pulse mode. The third light intensity is greater than the second light intensity, and the third dosing amount is greater than the second dosing amount. S21. When the influent turbidity is less than or equal to the third threshold, it is determined to be in the first turbidity range. The control unit controls the coagulant dosing submodule to reduce the dosing amount by the first ratio based on the dosing amount corresponding to the current organic load range, and controls the cross-flow control module to operate at the first cross-flow velocity. S22. When the third threshold < influent turbidity ≤ fourth threshold, it is determined to be the second turbidity range. The control unit controls the coagulant dosing submodule to keep the dosing amount corresponding to the current organic load range unchanged, and controls the cross-flow control module to run at the second cross-flow velocity. S23. When the influent turbidity is greater than the fourth threshold, it is determined to be in the third turbidity range. The control unit controls the coagulant dosing submodule to increase the second ratio based on the dosing amount corresponding to the current organic load range, and controls the cross-flow control module to operate at the third cross-flow velocity. S31. When the transmembrane pressure difference of ultrafiltration is less than or equal to the fifth threshold, it is determined to be the first pressure difference interval. The control unit controls the cross-flow control module to keep the cross-flow velocity corresponding to the current organic load interval unchanged, and controls the pulse component to keep the pulse mode corresponding to the current organic load interval unchanged. S32. When the fifth threshold < ultrafiltration transmembrane pressure difference ≤ the sixth threshold, it is determined to be the second pressure difference interval. The control unit controls the cross-flow control module to increase the first flow rate increment based on the cross-flow velocity corresponding to the current organic load interval, and controls the pulse component to switch to continuous operation mode and increase the first voltage increment. S33. When the transmembrane pressure difference of ultrafiltration is greater than the sixth threshold, it is determined to be the third pressure difference range. The control unit controls the cross-flow control module to increase the cross-flow rate to the upper limit value, controls the pulse component to run continuously at the highest voltage, and outputs a chemical cleaning reminder signal.

2. The control method for the integrated short-process water treatment device based on photocatalysis-coagulation-ultrafiltration as described in claim 1, characterized in that, The linkage control module also includes an influent turbidity acquisition unit connected to the control unit; The water turbidity collection unit is located at the water inlet of the housing; The control unit is also used to adjust the dosage of the coagulant dosing submodule and the crossflow velocity based on the signal collected by the influent turbidity acquisition unit.

3. The control method for the integrated short-process water treatment device based on photocatalysis-coagulation-ultrafiltration as described in claim 2, characterized in that, The linkage control module also includes an ultrafiltration transmembrane pressure differential acquisition unit connected to the control unit; The ultrafiltration transmembrane pressure difference acquisition unit is located at the upper end of the hollow fiber ultrafiltration membrane module and at the product water outlet of the shell; The control unit is also used to adjust the crossflow velocity and the pulse mode of the pulse component based on the signal acquired by the ultrafiltration transmembrane pressure difference acquisition unit.

4. The control method for the integrated short-process water treatment device based on photocatalysis-coagulation-ultrafiltration as described in claim 1, characterized in that, The catalytic component is a support mesh with photocatalytic material on its surface; The photocatalytic material is a composite of one of the following: metal oxide, metal sulfide, and metal nitride, and a carbon-based material; the support mesh is one of the following: metal mesh, carbon-based mesh, and glass fiber mesh.

5. The control method for the integrated short-process water treatment device based on photocatalysis-coagulation-ultrafiltration as described in claim 1, characterized in that, The hollow fiber ultrafiltration membrane module is made of one of the following materials: polyethersulfone, polyvinylidene fluoride, polyacrylonitrile, and polyvinyl chloride.

Images