CN107986538A - A kind of optoacoustic is electrically coupled can field multi-stage oxidizing-UF membrane collaboration water treatment system and technique - Google Patents

Abstract

The invention relates to a photoacoustic-electric coupling energy field multi-stage oxidation-membrane separation cooperative water treatment system and process, including three parts: a photoacoustic-electric coupling energy field multi-stage oxidation unit, a double-membrane separation unit, and a disinfection and sterilization unit; The electric coupling energy field multistage oxidation unit includes a photoacoustic electric coupling energy field multistage oxidation reactor equipped with a photoacoustic ozone joint oxidation reaction zone and an electrochemical oxidation adsorption reaction zone; the double membrane separation unit consists of a first-stage nanocomposite ultrafiltration It is composed of a membrane and a second-stage nanocomposite nanofiltration membrane; the disinfection and sterilization unit adopts an ultraviolet sterilizer. The present invention utilizes the coupling and synergy existing among technologies such as ozone oxidation, ultraviolet light oxidation, ultrasonic oxidation, activated carbon adsorption, electrochemical oxidation, and membrane separation, and integrates them efficiently to form an inseparable whole. The reaction system can separate and remove organic pollutants in water after multi-stage oxidation degradation, and effectively remove inorganic salts, especially high-valent salt ions.

Description

A photoacoustic electric coupling energy field multi-stage oxidation-membrane separation collaborative water treatment system and its craft

technical field

The invention belongs to the technical field of water supply treatment, and mainly relates to drinking water treatment, in particular to a multi-stage oxidation-membrane separation cooperative water treatment system and process through photoacoustic-electric coupling energy field, especially suitable for treating slightly polluted brackish water.

Background technique

At present, my country is facing the dual dilemma of water quality-based water shortage and water quantity-based water shortage. The problem of micro-pollution of drinking water sources is becoming more and more serious. Dissolved organic pollutants in micro-polluted water source water are difficult to remove under conventional treatment conditions. Exploring a safe and efficient micro-pollution water treatment technology is an effective way to solve water quality-related water shortages At the same time, the shortage of fresh water resources is also one of the problems that need to be solved urgently. Therefore, using unconventional water resources development and utilization technologies such as brackish water desalination to solve the shortage of fresh water resources and provide safe, reliable and hygienic production and domestic water is an important way to alleviate the water consumption. effective solution to water scarcity. Brackish water is generally ground water, but in the arid and semi-arid areas of Northwest inland rivers downstream and the Yellow River Basin, brackish water is mostly surface water, and due to geographical environment, climatic conditions, geological structure, salt accumulation and pollutants Due to comprehensive factors such as discharge, some water quality indicators in the surface water bodies in these areas exceed the Class III water body standards of the "Surface Water Environmental Quality Standards", which are manifested by higher comprehensive index values of organic matter, higher ammonia nitrogen concentration, and complex water body components containing suspended particles and colloidal substances. , algae, organic matter and bacteria and other microorganisms. Therefore, the brackish water in these areas is mostly brackish water that is polluted by non-point sources, causing water quality indicators such as fluoride ions, COD _Mn , ammonia nitrogen, and turbidity to exceed the standard, that is, slightly polluted brackish water.

At present, there are four main types of treatment processes for slightly polluted water at home and abroad, namely enhanced conventional treatment, pretreatment, advanced treatment and combined technology. The enhanced conventional treatment process mainly includes three technologies: enhanced coagulation, sedimentation and enhanced filtration. Although it can improve the removal effect of natural organic pollutants in water, it needs to add more coagulants and other chemicals, resulting in increased costs of chemicals and sludge treatment. , There are also many technical difficulties in the operation and management process. The pretreatment process mainly includes biological pretreatment and chemical oxidation pretreatment. Although it can remove organic matter that is difficult to remove by traditional processes, reduce chlorine consumption in water treatment, and improve effluent water quality, it also has negative effects, such as chemical pre-oxidation that may increase the mutagenicity of the final effluent. Advanced treatment processes include adsorption treatment, photocatalytic oxidation, membrane technology, etc. Among the adsorption treatment technologies, activated carbon, as the most commonly used adsorbent, can effectively remove pollutants such as dissolved organic carbon in water, and has been widely used in water purification treatment processes at home and abroad. Photocatalytic oxidation technology has a strong oxidation ability, can completely mineralize organic matter, and has a good removal effect on phenols and chlorinated organic matter in water, but the photocatalyst is inconvenient to recycle, resulting in limited use. Membrane separation technology includes microfiltration, ultrafiltration, nanofiltration and reverse osmosis, etc. It has the characteristics of large separation coefficient, wide application range, simple device, small footprint, and high degree of automation. It can effectively remove odor and color in water. , precursors of disinfection by-products, microorganisms, viruses and other pollutants. The ozone activated carbon process combines the strong oxidation of ozone with the adsorption of activated carbon, and is a typical combination technology for micro-polluted water treatment. Macromolecular organic matter in water can be oxidized into small molecular organic matter by ozone, which improves the biodegradability of organic matter and is easier to be removed by subsequent activated carbon units.

At present, the ways and methods of desalination of brackish water used at home and abroad are mainly desalination processes with electrodialysis, reverse osmosis, and nanofiltration as the core. The electrodialysis process has simple process, high desalination rate, and convenient operation, but the water recovery rate is low, and it has no ability to remove uncharged substances such as organic matter, colloid, bacteria, suspended matter, etc., which makes it suitable for desalination of brackish water. Applications in engineering are limited. Reverse osmosis salt water desalination technology has a wide range of applications and safe effluent water quality, but there are harsh pretreatment requirements, strict pretreatment requirements, complex systems, and difficult treatment of the concentrated water produced. While removing salt, it also removes the beneficial to human body. Elements. The cut-off performance of the nanofiltration membrane is between the ultrafiltration membrane and the reverse osmosis membrane. Based on the pore size and chargeability of the nanofiltration membrane, it has special ion selectivity in the separation process, and can intercept small molecular organic compounds that the ultrafiltration membrane cannot intercept. , and can partially penetrate ions that are beneficial to the human body. Due to the small pore size of the nanofiltration membrane, deposition is easy to occur on the membrane, and excessive deposition will cause membrane pollution, which will affect the service life and treatment effect of the membrane. If there is a good solution to the pollution problem in the nanofiltration process, the nanofiltration membrane process The application prospect will be broader.

Compared with conventional water treatment technology, advanced oxidation technology has the advantages of wide application range, fast reaction rate, fast oxidation rate, etc., and has a good application prospect in the field of water treatment. The reaction involves the oxidation process of hydroxyl radicals, which belongs to the advanced oxidation process, also known as advanced oxidation technology. The advanced oxidation process produces a large number of very active hydroxyl radicals. Hydroxyl radicals are intermediate products of the reaction, which can induce subsequent chain reactions. Hydroxyl radicals directly react with pollutants in water and degrade them into carbon dioxide and water. Molecular inorganic substances will not produce secondary pollution. Due to their special advantages, various advanced oxidation technologies are gradually emerging in the field of drinking water treatment. In particular, technologies such as ozone oxidation, photocatalytic oxidation, electrocatalytic oxidation, and ultrasonic catalytic oxidation have attracted widespread attention because of their advantages such as simple equipment, easy control, high treatment efficiency and good effect. The application of ozone in the water treatment process is based on the advantages of strong oxidizing ability and fast reaction of ozone, which can remove various organic pollutants in water. However, ozone alone also has problems such as high cost and low utilization rate. Photocatalytic oxidation alone has problems such as large dosage of photocatalyst, easy agglomeration in water, poisoning and deactivation, and difficulty in cleaning and recycling, which affect the photocatalytic efficiency. The electrochemical treatment ability alone is strong, but the treatment efficiency is low. Single organic matter has its specific optimal degradation frequency and sound intensity when ultrasonically treated alone, but there are different types of organic matter in actual water bodies, so it is necessary to further research and develop ultrasonic reactors with synergistic effects of frequency and sound intensity or the combination of ultrasonic degradation and other technologies. United craft.

Although the application of advanced oxidation technology, membrane method and other technologies in the field of drinking water treatment is increasing year by year, and related research results are also increasing, most of the results focus on the research of a single technology or a typical combined process. The pollutants removed by these technologies Targeted, it is difficult to adapt to the treatment of complex water quality and meet people's increasingly high water treatment needs. To achieve the ideal treatment effect, it should be the coordinated treatment of multiple technologies. Therefore, there is a lack of research on integrated and systematized technologies at this stage, and the existing research cannot meet the requirements of engineering research and development feasibility of processes, equipment, and technologies. This is a technical problem that needs to be solved urgently in this field.

Contents of the invention

Aiming at the problem that the existing technology is difficult to remove some refractory organic pollutants and high-priced inorganic salts in micro-polluted brackish water, the invention provides a photoacoustic-electrical coupling energy field multi-stage oxidation-membrane separation cooperative water treatment system.

In order to solve the above problems, the present invention adopts the following technical scheme: a photoacoustic and electric coupling energy field multi-stage oxidation-membrane separation cooperative water treatment system, including a photoacoustic and electric coupling energy field multi-stage oxidation unit, a double-membrane separation unit, a disinfection bacterial unit;

The photoacoustic electric coupling energy field multistage oxidation unit includes a photoacoustic electric coupling energy field multistage oxidation reactor, which is divided into a photoacoustic ozone combined oxidation reaction area, a water distribution area, and an electrochemical oxidation reaction area arranged in sequence by partitions. The adsorption reaction area and the water outlet area; the photoacoustic ozone combined oxidation reaction area communicates with the top of the water distribution area as the first-order reaction area; the electrochemical oxidation adsorption reaction area communicates with the bottom of the water distribution area and the top of the water outlet area as the second-order reaction area; The ozone joint oxidation reaction zone is equipped with ultraviolet lamps, ozone aerators and ultrasonic transducers in zone I; the bottom of the electrochemical oxidation adsorption reaction zone is equipped with ultrasonic transducers in zone II, and the lower part is equipped with porous water distribution plates in zone II. The upper part is equipped with a porous water outlet plate in zone II, and an adsorption filler is sandwiched between the two plates;

The double-membrane separation unit includes a first-stage nanocomposite ultrafiltration membrane and a second-stage nanocomposite nanofiltration membrane; the water inlet end of the first-stage nanocomposite ultrafiltration membrane is connected to a self-priming water inlet pump, and the water outlet end of the first stage nanocomposite ultrafiltration membrane Connect with the water inlet end of the second-stage nanocomposite nanofiltration membrane;

The disinfection and sterilization unit includes an ultraviolet sterilizer, the top of the ultraviolet sterilizer has a water inlet, and the bottom has a water outlet; the top water inlet of the ultraviolet sterilizer is connected to the fresh water outlet of the second-stage nanocomposite nanofiltration membrane , the water outlet at the bottom is used to discharge the purified water.

Preferably, the adsorption filler is granular activated carbon, the surface of which is loaded with zero-valent iron, the adsorption filler is used as a cathode, and the loaded zero-valent iron is used as an anode to form a primary battery to form a micro electric field.

Further, the ozone aerator provides ozone through an ozone generator provided outside the photoacoustic electric coupling energy field multi-stage oxidation reactor, and the ozone generator is connected to a power supply.

Further, it also includes an ultrasonic controller for controlling the ultrasonic transducers in zone I and zone II, the ultrasonic controller is connected to the ultrasonic generator, and the ultrasonic controller and the ultrasonic generator are respectively connected to the power supply.

Another object of the present invention is to provide a process for co-processing some refractory organic pollutants and high-priced inorganic salts in slightly polluted brackish water using the above-mentioned system for photoacoustic-electric coupling energy field multi-stage oxidation-membrane separation, which specifically includes the following steps :

Step (1), stage I reaction: the water to be treated enters the photoacoustic ozone joint oxidation reaction zone, the intermittent multi-frequency ultrasonic waves emitted by the ultrasonic transducer in zone I, the ozone entering the reaction system through the ozone aerator, and ultraviolet rays Under the joint and synergistic action of the ultraviolet light generated by the lamp, hydroxyl radicals are generated in the reaction system, which oxidizes and degrades the organic pollutants in the water body;

Step (2), second-order reaction: the effluent after oxidative degradation in zone I is evenly distributed into the electrochemical oxidation adsorption reaction zone through the water distribution zone, and the intermittent multi-frequency ultrasonic waves emitted by the ultrasonic transducer in zone I are coupled with the adsorption filler Under the synergistic effect, hydroxyl radicals are continuously generated in the reaction system to continue to oxidize and degrade the organic pollutants in the water body, and the degraded small molecular organic matter is physically adsorbed by the adsorption filler; the ozone that does not fully participate in the reaction in step (1) enters the second level Under the joint action of the reaction zone and the adsorption filler, new colloidal particles are produced in the reaction system, and the central colloid core is an insoluble particle formed by Fe(OH) ₃ polymerization, and the insoluble particle adsorbs small molecular organic pollutants;

Step (3), membrane separation: the water treated in the electrochemical oxidation adsorption reaction zone enters the water outlet area to precipitate and discharge the colloidal particles adsorbed with small molecular organic pollutants, and the precipitated effluent is output through a self-priming water inlet pump The macromolecular organic pollutants are removed in the first-stage nanocomposite ultrafiltration membrane of the double-membrane separation unit, and the produced water then enters the second-stage nanocomposite nanofiltration membrane to further remove small molecule organic pollutants and inorganic salts;

Step (4), disinfection and sterilization: the fresh water of the second-stage nano-composite nanofiltration membrane then enters the disinfection and sterilization unit, and is sterilized by an ultraviolet sterilizer before being discharged.

In step (1) of the present invention, the ultrasonic transducer in zone I emits intermittent multi-frequency ultrasonic waves, and the reaction temperature in the entire process reaction system is kept at 20-35 degrees Celsius through intermittent ultrasonic action.

In step (2) of the present invention, the ultrasonic transducer in zone II emits ultrasonic waves periodically to desorb and regenerate the adsorption filler.

A photoacoustic-electric coupling energy field multi-stage oxidation-membrane separation cooperative water treatment process of the present invention is suitable for treating slightly polluted brackish water.

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

1. The present invention integrates various technologies efficiently by utilizing the coupling and synergy among technologies such as ozone oxidation, ultraviolet light oxidation, ultrasonic oxidation, activated carbon adsorption, electrochemical oxidation, and membrane separation to form an inseparable whole. The combined and synergistic reaction system strengthens the removal effect of the reaction system on organic pollutants in water. The water treatment in the reaction system specifically passes through three treatment units, which can separate and remove the organic pollutants in the water body after multi-stage oxidation degradation, and at the same time effectively remove the inorganic salts in the water body, especially high-priced salt ions, and realize various Process synergy, complement each other, and the efficient combination of advanced oxidation and activated carbon adsorption enhances the pretreatment effect of water body, strengthens the separation effect of the membrane separation unit, significantly improves the water quality entering the membrane separation unit, reduces membrane pollution, and prolongs the life of the membrane separation unit. The cleaning cycle of the membrane is shortened, thereby increasing the service life of the membrane.

2. The first-order reaction of the present invention: the ultrasonic transducer in the first zone emits intermittent multi-frequency ultrasonic waves, which ensures a suitable reaction temperature in the entire process reaction system through intermittent ultrasonic action, and then strengthens the treatment effect of the process on low-temperature water in winter . Under the intensification of intermittent multi-frequency ultrasonic waves, ultrasonic waves, ozone and ultraviolet light all generate high concentrations of hydroxyl radicals in the reaction system to oxidize and degrade organic pollutants; and the combined effect of intermittent multi-frequency ultrasonic waves, ozone and ultraviolet light will Multistage oxidative degradation of organic pollutants. Among them, the ultraviolet light is fully mixed with the water body under the intensification of the ultrasonic wave, which improves the contact oxidation efficiency between the ultraviolet light and the organic pollutants in the water body, and accelerates the redox reaction rate in the reaction system; at the same time, under the combined action of the ultraviolet light and ozone , more hydroxyl radicals are generated in the reaction system to oxidize and degrade organic pollutants.

3. The second-order reaction of the present invention: the adsorption filler is granular activated carbon, and its surface is loaded with zero-valent iron. The adsorption filler is used as the cathode, and the zero-valent iron is used as the anode to form a primary battery to form a micro-electric field. Under the synergistic effect of emitting ultrasonic waves and adsorbing filler particles, a Fenton-like reaction occurs in the reaction system, and hydroxyl radicals are continuously generated, which continue to oxidize organic pollutants, and the ultrasonic waves emitted by the ultrasonic transducer in zone I form a combination of ultrasonic field and micro-electric field. Under the coupling synergy, the ultrasonic field strengthens the mass transfer of the micro-electric field, increases the concentration of hydroxyl radicals in the reaction system, and strengthens the treatment effect of the reaction system on organic pollutants, so that organic pollutants can participate in direct or indirect redox The reaction degrades. After the ozone that does not fully participate in the reaction in the first-level reaction zone enters the second-level reaction zone, it not only continues to oxidize and degrade organic pollutants, but also forms a joint action between ozone and the adsorption filler particles in the adsorption filler to form a central colloidal particle, which is composed of many Fe (OH) ₃ is an insoluble particle with a huge specific surface area, which can adsorb and remove small molecular organic pollutants after oxidative degradation from the system, which not only further improves the removal effect of organic pollutants and the utilization of ozone Efficiency, and effectively treat the ozone that does not fully participate in the reaction in the first-level reaction zone, thereby avoiding the subsequent nanocomposite ultrafiltration membrane and nanocomposite nanofiltration membrane oxidized by residual ozone, reducing the membrane separation effect and reducing the service life of the membrane. In the present invention, organic pollutants are degraded by multistage oxidation and then adsorbed and removed under the combined action of intermittent multi-frequency ultrasonic wave, ozone, micro-electric field and active carbon in zone I.

Membrane separation of the present invention: the water treated in the second-stage reaction zone enters the water outlet area to precipitate the colloidal particles produced, and the sediment is discharged through the emptying valve; the precipitated water enters the double-membrane separation unit through the self-priming water inlet pump , first enter the first-stage nanocomposite ultrafiltration membrane to remove organic pollutants with relatively large molecular weight after multi-stage oxidation in the I and II reaction zones, and then enter the second-stage nanocomposite nanofiltration membrane to further remove small molecular organic pollutants. Pollutants and inorganic salts; the concentrated water of the first-stage nanocomposite ultrafiltration membrane is discharged through the drain valve, and the concentrated water of the second stage nanocomposite nanofiltration membrane is discharged through the drain valve. Furthermore, under the synergistic effect of photoacoustic-electric coupling energy field multi-stage oxidation and membrane separation, the multi-stage oxidative degradation and removal of organic pollutants in water, as well as the effective removal of inorganic salts, especially high-priced salt ions, have been strengthened. The effect of the reaction system on the removal of organic pollutants and inorganic salts in water.

Description of drawings

Figure 1 is a schematic diagram of a multi-stage oxidation-membrane separation cooperative water treatment system with photoacoustic and electric coupling energy field of the present invention;

Fig. 2 is a photoacoustic electric coupling energy field multi-stage oxidation-membrane separation collaborative water treatment process flow chart of the present invention.

In the figure: 1. Photoacoustic electric coupling energy field multi-stage oxidation reactor; 2. Nanocomposite ultrafiltration membrane; 3. Nanocomposite nanofiltration membrane; 4. UV sterilizer; 5. Photoacoustic ozone combined oxidation reaction zone; 6. Water distribution area; 7. Electrochemical oxidation adsorption reaction area; 8. Outlet area; 9. Ozone generator; 10. Ozone aerator; 11. Ultraviolet lamp; ;14. Ultrasonic controller; 15. Ultrasonic transducer in Zone Ⅰ; 16. Porous water distribution plate in Zone Ⅱ; 17. Adsorption packing; 18. Ultrasonic transducer in Zone Ⅱ; 19. Porous water outlet plate in Zone Ⅱ; 21. Empty valve; 22. The first-stage nanocomposite ultrafiltration membrane concentrated water drain valve; 23. The second stage nanocomposite nanofiltration membrane concentrated water drain valve.

Detailed ways

In order to better understand the present invention, the technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and specific embodiments. Apparently, the described embodiments are a part of the embodiments of the present invention, but not all of them, and the protection scope of the present invention is not limited to the following embodiments.

As shown in Figure 1, a photoacoustic electric coupling energy field multistage oxidation-membrane separation collaborative water treatment system includes the following processing units: photoacoustic electric coupling energy field multistage oxidation unit, double membrane separation unit, disinfection and sterilization unit ;

The photoacoustic electric coupling energy field multistage oxidation unit includes a photoacoustic electric coupling energy field multistage oxidation reactor 1, and the reactor is sequentially separated into a photoacoustic ozone combined oxidation reaction zone 5, a water distribution zone 6, The electrochemical oxidation and adsorption reaction zone 7, the water outlet zone 8, the photoacoustic ozone combined oxidation reaction zone 5 is used as the first-level reaction zone, and the electrochemical oxidation and adsorption reaction zone 7 is used as the second-level reaction zone; the left side of the photoacoustic ozone combined oxidation reaction zone 5 The lower part is provided with a water inlet, and the right side is provided with a zone I water outlet partition 12; the top of the I zone water outlet partition 12 communicates with the water distribution area 6; the bottom of the right partition of the water distribution area 6 communicates with the electrochemical oxidation adsorption reaction area 7 Communication; the top of the right partition of the electrochemical oxidation adsorption reaction zone 7 communicates with the water outlet area 8; the lower part of the water outlet area 8 is connected to the emptying valve 21, and the upper part of the water outlet area 8 is connected to the water inlet end of the self-priming water inlet pump 20.

The photoacoustic ozone joint oxidation reaction zone 5 is equipped with an ultraviolet lamp 11, an ozone aerator 10 and an ultrasonic transducer 15 in zone I; the bottom of the electrochemical oxidation adsorption reaction zone 7 is provided with an ultrasonic transducer 18 in zone II 1. The lower part is equipped with a porous water distribution plate 16 in zone II, and the upper part is equipped with a porous water outlet plate 19 in zone II. Adsorption filler 17 is sandwiched between the porous water distribution plate 16 in zone II and the porous water outlet plate 19 in zone II. The adsorption filler 17 is granular activated carbon. The surface is loaded with zero-valent iron, the adsorption filler is used as the cathode, and the zero-valent iron is loaded as the anode to form a primary battery to form a micro electric field. The ozone aerator 10 communicates with the ozone generator 9 outside the photoacoustic electric coupling energy field multi-stage oxidation reactor 1 through pipelines, and ozone is provided by the ozone generator 9, and the ozone generator 9 is connected with a power supply; the outside of the ultraviolet lamp 11 has The supporting quartz sleeve, the quartz sleeve is fixedly connected to the top of the photoacoustic-electric coupling energy field multi-stage oxidation reactor 1; the ultrasonic transducer 15 in zone I and the ultrasonic transducer 18 in zone II are controlled by an ultrasonic controller 14, The ultrasonic controller 14 is connected to the ultrasonic generator 13, and the ultrasonic controller 14 and the ultrasonic generator 13 are respectively connected to a power supply.

The double-membrane separation unit includes a first-stage nanocomposite ultrafiltration membrane 2 and a second-stage nanocomposite nanofiltration membrane 3; The water outlet of the water inlet pump is connected, and the water outlet of the first-stage nanocomposite ultrafiltration membrane 2 is connected to the water inlet of the second-stage nanocomposite nanofiltration membrane 3 . Concentrated water drain valves are respectively provided at the bottoms of the first-stage nanocomposite ultrafiltration membrane 2 and the second-stage nanocomposite nanofiltration membrane 3 .

The first-stage nanocomposite ultrafiltration membrane 2 is a nanomaterial composite membrane. The nanomaterial is one or more of nanomaterials such as carbon nanotubes, graphene, and zeolite. The introduction of different types of nanomaterials improves the first-stage nanocomposite membrane. Ultrafiltration membrane 2 has hydrophilic properties and organic pollution resistance; the nanomaterials are chemically modified, and the dispersion of nanoparticles and the compatibility with the polymer membrane matrix are improved after modification, thereby further improving the first-level nanocomposite Separation performance of ultrafiltration membrane 2. The second-level nanocomposite nanofiltration membrane 3 is a nanomaterial composite membrane, and the nanomaterial is one or more of nanomaterials such as carbon nanotubes, graphene, and zeolite. The introduction of different types of nanomaterials improves the second-level nanocomposite membrane. The membrane flux and desalination and desalination performance of the nanofiltration membrane 3; the nanomaterials are chemically modified, and the dispersion of the nanoparticles and the compatibility with the polymer membrane matrix are improved after modification, which further improves the second-level nanocomposite Separation performance of nanofiltration membrane 3.

The disinfection and sterilization unit includes an ultraviolet sterilizer 4, the top of the ultraviolet sterilizer 4 has a water inlet, and the bottom has a water outlet. The fresh water outlet is connected, and the outlet at the bottom is used to discharge the purified water.

As shown in Figure 2, a photoacoustic electric coupling energy field multi-stage oxidation-membrane separation collaborative water treatment process specifically includes the following steps:

Step (1): Stage I reaction: After the water to be treated enters the photoacoustic electric coupling energy field multistage oxidation unit, in the stage I reaction zone, the ultrasonic transducer 15 in zone I emits intermittent multi-frequency ultrasonic waves, and in the intermittent multi-frequency Under the action of ultrasound, the reaction occurs , the reaction system produces a high concentration of hydroxyl radicals to oxidize and degrade the organic pollutants in the water; and the intermittent emission of ultrasonic waves provides a certain reaction time for the hydroxyl radicals generated by the ultrasonic action, reducing the excessive accumulation of hydroxyl radicals and free The probability of combination strengthens the effect of ultrasonic treatment on organic pollutants in water; through the intermittent ultrasonic action, the appropriate reaction temperature in the entire process reaction system is guaranteed, thereby strengthening the treatment effect of the process on low-temperature water in winter.

In the first-level reaction zone, ozone decomposes unstablely under the action of ultrasonic waves: , , , a high concentration of hydroxyl radicals are produced in the reaction system, which oxidizes and degrades organic pollutants; the ultraviolet light is fully mixed with the water body under the action of ultrasonic waves, which improves the contact oxidation efficiency of ultraviolet light and organic pollutants in the water body, and ultrasonic transmission The energy of the ultraviolet light will strengthen the effect of ultraviolet light on organic pollutants, reduce the band gap energy of organic pollutants, and speed up the breakage of related groups. A more oxidizing group is formed, and then chemically reacts with organic pollutants. The specific reaction is: , which strengthens the treatment effect of the reaction system on organic pollutants; under the combined action of ultraviolet light and ultrasonic waves emitted by the ultrasonic transducer 15 in zone I, a reaction occurs: , , , a high concentration of hydroxyl radicals is produced in the reaction system, which strengthens the oxidation effect of ultraviolet light on organic pollutants; under the combined action of ultraviolet light and ozone, the reaction occurs: , , more hydroxyl radicals are generated in the reaction system to oxidize and degrade organic pollutants.

Step (2): Level II reaction: the water after oxidative degradation in the level I reaction zone is evenly distributed into the level II reaction zone through the water distribution zone 6, and the adsorption filler 17 is granular activated carbon, and its surface is loaded with zero-valent iron to adsorb the filler As the cathode, the zero-valent iron is loaded as the anode to form a primary battery to form a micro-electric field. Under the synergistic effect of the ultrasound emitted by the ultrasonic transducer 15 in zone I and the coupling of the adsorption filler particles, a Fenton-like reaction occurs in the reaction system, and hydroxyl radicals are continuously generated. : , , , , , which strengthens the oxidative degradation effect of the reaction system on organic pollutants; organic pollutants can participate in direct or indirect redox reactions: , so that it is degraded; the ultrasonic transducer 15 in zone I emits ultrasonic waves to form the coupling synergistic effect of the ultrasonic field and the micro-electric field, and the ultrasonic field strengthens the mass transfer of the micro-electric field and reacts , , , The concentration of hydroxyl radicals in the reaction system is increased, and the treatment effect of the reaction system on organic pollutants is enhanced; the degraded small molecular organic matter enters the micropores of the adsorption filler particles and is physically adsorbed. After the ozone that does not fully participate in the reaction in the photoacoustic ozone combined oxidation reaction zone 5 enters the electrochemical oxidation adsorption reaction zone 7, the reaction occurs under the joint action of ozone and adsorption filler particles: , anodic reaction , , when there In the presence of , , (neutral or alkaline solution), , new colloidal particles are produced in the reaction system, and the central colloid core is an insoluble particle with a large specific surface area formed by the polymerization of many Fe(OH) ₃ , which makes it easy to adsorb small molecular organic pollutants; the second-order reaction The ultrasonic transducers 18 in zone II in the zone regularly emit ultrasonic waves so that the adsorption filler 17 can be desorbed and regenerated periodically.

Steps (1) and (2) completed the multi-stage oxidation and adsorption removal of organic pollutants in water under the coupling synergy of ozone oxidation, ultraviolet light oxidation, ultrasonic oxidation, electrochemical oxidation, and activated carbon adsorption technology, which strengthened the The effect of the reaction system on the removal of organic pollutants in water.

Step (3): The water treated in the second-stage reaction zone enters the water outlet area 8 to precipitate the colloidal particles produced, and the sediment is discharged through the emptying valve 21; the settled effluent enters the double membrane through the self-priming water inlet pump 20 The separation unit first enters the first-stage nanocomposite ultrafiltration membrane 2 to remove organic pollutants with relatively large molecular weights after multi-stage oxidation in the I and II reaction zones, and then the produced water enters the second-stage nanocomposite nanofiltration membrane 3 for further Remove small molecule organic pollutants and inorganic salts; the concentrated water of the first-stage nanocomposite ultrafiltration membrane 2 is discharged through the drain valve 22, and the concentrated water of the second stage nanocomposite nanofiltration membrane 3 is discharged through the drain valve 23; Under the coupling synergistic effect of multi-stage oxidation of acoustic-electric coupling energy field and membrane separation, the organic pollutants and inorganic salts, especially high-valent salt ions in the water body after multi-stage oxidation degradation have been effectively removed, and the reaction system has strengthened the effect on the water body. The removal effect of organic pollutants and inorganic salts.

Step (4): The fresh water from the second-stage nano-composite nanofiltration membrane 3 then enters the disinfection and sterilization unit, and the effluent after being sterilized by the ultraviolet sterilizer 4 is used as drinking water.

Claims (8)

1. A photoacoustic-electrical coupling energy field multi-stage oxidation-membrane separation collaborative water treatment system, characterized in that: it includes a photoacoustic-electrical coupling energy field multi-stage oxidation unit, a double-membrane separation unit, and a disinfection unit; The photoacoustic electric coupling energy field multistage oxidation unit includes a photoacoustic electric coupling energy field multistage oxidation reactor (1), which is divided into sequentially arranged photoacoustic ozone combined oxidation reaction zones (5), The water distribution area (6), the electrochemical oxidation adsorption reaction area (7) and the water outlet area (8); the photoacoustic ozone combined oxidation reaction area (5) is connected to the top of the water distribution area (6) as the first-level reaction area; the electrochemical oxidation adsorption The reaction zone (7) is connected to the bottom of the water distribution zone (6) and the top of the water outlet zone (8) as a secondary reaction zone; the photoacoustic ozone combined oxidation reaction zone (5) is equipped with ultraviolet lamps (11), ozone aeration device (10) and ultrasonic transducer (15) in Zone I; the bottom of the electrochemical oxidation adsorption reaction zone (7) is equipped with an ultrasonic transducer in Zone II (18), and the lower part is equipped with a porous water distribution plate in Zone II (16) , The upper part is equipped with a porous water outlet plate (19) in zone II, and an adsorption filler (17) is sandwiched between the two plates; The double-membrane separation unit includes a first-stage nanocomposite ultrafiltration membrane (2) and a second-stage nanocomposite nanofiltration membrane (3); the water inlet end of the first-stage nanocomposite ultrafiltration membrane (2) and the self-priming The water inlet pump (20) is connected, and the outlet end of its produced water is connected to the water inlet end of the second-stage nanocomposite nanofiltration membrane (3); The disinfection and sterilization unit includes an ultraviolet sterilizer (4), the top of the ultraviolet sterilizer (4) has a water inlet, and the bottom has a water outlet; the top water inlet of the ultraviolet sterilizer (4) is connected to the second stage The nanocomposite nanofiltration membrane (3) is connected to the fresh water outlet, and its bottom outlet is used to discharge the purified water. 2. A photoacoustic electric coupling energy field multi-stage oxidation-membrane separation collaborative water treatment system according to claim 1, characterized in that: the adsorption filler (17) is granular activated carbon, and its surface is loaded with zero-valent iron, with The adsorption filler is the cathode, and the loaded zero-valent iron is the anode to form the primary battery to form a micro electric field. 3. A photoacoustic electric coupling energy field multi-stage oxidation-membrane separation collaborative water treatment system according to claim 1, characterized in that: the ozone aerator (10) reacts through the photoacoustic electric coupling energy field multi-stage oxidation reaction An ozone generator (9) provided outside the device (1) provides ozone, and the ozone generator (9) is connected to a power supply. 4. A photoacoustic electric coupling energy field multi-stage oxidation-membrane separation collaborative water treatment system according to claim 1, characterized in that it also includes an ultrasonic transducer (15) for controlling the ultrasonic transducer (15) in zone I and the ultrasonic wave in zone II The ultrasonic controller (14) of the transducer (18), the ultrasonic controller (14) is connected to the ultrasonic generator (13), and the ultrasonic controller (14) and the ultrasonic generator (13) are respectively connected to a power supply. 5. A photoacoustic electric coupling energy field multi-stage oxidation-membrane separation collaborative water treatment process according to any one of claims 1-4, characterized in that it specifically comprises the following steps: Step (1), stage I reaction: the water to be treated enters the photoacoustic ozone joint oxidation reaction zone (5), and the intermittent multi-frequency ultrasonic waves emitted by the ultrasonic transducer (15) in zone I pass through the ozone aerator (10 ) the ozone entering the reaction system and the ultraviolet light generated by the ultraviolet lamp (11) produce hydroxyl radicals in the reaction system under the combined synergistic effect of the three, and oxidize and degrade the organic pollutants in the water body; Step (2), second-order reaction: the effluent after oxidative degradation in zone I is uniformly distributed through the water distribution zone (6) and enters the electrochemical oxidation adsorption reaction zone (7). Under the coupling and synergistic effect of multi-frequency ultrasonic wave and adsorption filler (17), hydroxyl radicals are continuously generated in the reaction system, and continue to oxidize and degrade organic pollutants in the water body, and the degraded small molecule organic matter is physically adsorbed by the adsorption filler; the steps ( 1) Ozone that does not fully participate in the reaction enters the second-stage reaction zone and under the joint action of the adsorption filler, produces new colloidal particles in the reaction system. The central colloid core is an insoluble particle formed by Fe(OH) ₃ polymerization. The insoluble particles adsorb small molecular organic pollutants; Step (3), membrane separation: the water treated in the electrochemical oxidation adsorption reaction zone (7) enters the effluent zone (8) to precipitate and discharge the colloidal particles adsorbed with small molecular organic pollutants, and the effluent after precipitation passes through The self-priming water inlet pump (20) is output to the first-stage nano-composite ultrafiltration membrane (2) of the double-membrane separation unit to remove macromolecular organic pollutants, and the produced water then enters the second-stage nano-composite nanofiltration membrane (3) for further Remove small molecule organic pollutants and inorganic salts; Step (4), disinfection and sterilization: the fresh water from the second-stage nanocomposite nanofiltration membrane (3) then enters the disinfection and sterilization unit, and the water is sterilized by the ultraviolet sterilizer (4) and then discharged. 6. A photoacoustic electric coupling energy field multi-stage oxidation-membrane separation collaborative water treatment process according to claim 5, characterized in that: in step (1), the ultrasonic transducer (15) in zone I emits intermittent Multi-frequency ultrasonic waves keep the reaction temperature in the entire process reaction system at 20-35 degrees Celsius through intermittent ultrasonic action. 7. A photoacoustic electric coupling energy field multi-stage oxidation-membrane separation collaborative water treatment process according to claim 5, characterized in that: in step (2), the ultrasonic transducer (18) in zone II regularly emits ultrasonic waves Desorb and regenerate the adsorption filler (17). 8. A photoacoustic electric coupling energy field multi-stage oxidation-membrane separation collaborative water treatment process according to claim 5, characterized in that it is suitable for treating slightly polluted brackish water.