A piezoelectric catalytic degradation device for water pollutants

Abstract

The application provides a water body pollutant piezoelectric catalytic degradation device, which has the structure of a reactor cavity (1). A top water inlet (2) is arranged at the top of the reactor cavity (1), and a bottom water outlet (3) is arranged at the bottom of the reactor cavity (1). A two-dimensional agitation zone, a one-dimensional penetration zone and a zero-dimensional fluidization zone are arranged in the cavity of the reactor cavity (1), and a bubble fluidization excitation system is arranged outside the cavity of the reactor cavity (1). A hydraulic pulse circulation driving system is arranged outside the cavity of the reactor cavity (1) and is communicated with the top water inlet (2) and the bottom water outlet (3). The two-dimensional agitation zone, the one-dimensional penetration zone and the zero-dimensional fluidization zone are connected in a multi-dimensional cascade structure, so that the overall treatment efficiency of different forms of pollutants can be improved.

Description

Technical Field

[0001] This invention relates to a piezoelectric catalytic degradation device for water pollutants, belonging to the field of piezoelectric catalysis and water pollution control technology. Background Technology

[0002] With the continuous advancement of industrialization, the persistent discharge and accumulation of recalcitrant organic pollutants in water bodies have posed a long-term threat to ecosystem security and human health. Advanced oxidation technologies have attracted widespread attention due to their ability to effectively mineralize recalcitrant organic matter. Piezoelectric catalysis, as one of the emerging technological routes, can convert mechanical energy into electrical energy under external mechanical force, forming a built-in electric field on the surface of piezoelectric materials, promoting the directional separation of electron-hole pairs and generating reactive oxygen species (·OH, ·O2). - (etc.) to achieve the oxidative degradation of pollutants; compared with photocatalysis and electrocatalysis, piezoelectric catalysis does not depend on light conditions, nor does it require a continuous external power source. It is mainly driven by fluid kinetic energy and can achieve continuous operation in all weather conditions. It has good engineering application prospects in complex aquatic environments.

[0003] However, existing piezoelectric catalytic devices still have the following shortcomings in practical applications: First, most existing devices use single-form piezoelectric materials, resulting in a single force form and difficulty in achieving multi-dimensional synergistic excitation, leading to low utilization of the piezoelectric effect. Second, the existing system flow field control structure is imperfect, limiting gas-liquid mass transfer efficiency and making it difficult to form a stable and efficient disturbance environment within the reactor. Third, some devices rely on external high-energy excitation sources such as ultrasound, resulting in high energy consumption, complex equipment, and difficulty in large-scale application. Fourth, existing piezoelectric catalytic devices have limited functions, only possessing catalytic degradation capabilities and lacking the ability to perform tiered synergistic treatment of pollutants of different forms in water, resulting in limited overall purification efficiency. Therefore, there is an urgent need to provide a novel piezoelectric catalytic device that can achieve multi-dimensional synergistic excitation of piezoelectric materials, multi-functional tiered purification, and combined with gas-liquid flow control, in order to improve pollutant degradation efficiency and reduce system energy consumption. Summary of the Invention

[0004] The present invention proposes a piezoelectric catalytic degradation device for water pollutants, which aims to solve the problems of low excitation efficiency of piezoelectric materials and insufficient gas-liquid mass transfer efficiency in the prior art.

[0005] The technical solution of the present invention is a piezoelectric catalytic degradation device for water pollutants, the structure of which includes a reactor cavity 1; a top inlet 2 is provided at the top of the reactor cavity 1, and a bottom outlet 3 is provided at the bottom of the reactor cavity 1; a two-dimensional agitation zone, a one-dimensional penetration zone, a zero-dimensional fluidization zone, and a bubble fluidization excitation system are distributed inside the reactor cavity 1; a hydraulic pulse circulation drive system is provided outside the reactor cavity 1, and the hydraulic pulse circulation drive system connects the top inlet 2 and the bottom outlet 3.

[0006] Furthermore, the two-dimensional turbulence zone, the one-dimensional penetration zone, the zero-dimensional fluidization zone, and the bubble fluidization activation system are arranged sequentially from top to bottom inside the reactor cavity 1.

[0007] Furthermore, the hydraulic pulse circulation drive system includes a circulation pipe 5, a water pump 6, and a pulse controller 7; the top inlet 2 and the bottom outlet 3 are connected through the circulation pipe 5, the water pump 6 is installed on the circulation pipe 5, and the pulse controller 7 is electrically connected to the water pump 6.

[0008] Furthermore, the bubble fluidization activation system includes a micro-nano bubble aeration disc 11, which is horizontally positioned below the zero-dimensional fluidization zone. The micro-nano bubble aeration disc 11 is connected to an air pump 9 outside the reactor cavity 1 via an air inlet pipe 10, which passes through the side wall of the reactor cavity 1. During operation, the water pump 6 drives the water to be drawn out through the bottom outlet 3 and then reintroduced into the top inlet 2 through the circulation pipe 5, forming a water circulation within the body. The pulse controller 7 is electrically connected to the water pump 6 and periodically adjusts the start-stop frequency and flow rate of the water pump 6. The flow rate is adjusted so that the water entering the reactor chamber 1 forms a periodic variable-speed pulsed flow. Driven by the water pump 6 and the pulse controller 7, the pulsed flow is formed in the circulation pipe 5. The gas passes through the surface of the micro-nano bubble aeration disc 11 to form micro-nano bubbles. The micro-nano bubbles pass through the zero-dimensional fluidization zone and the one-dimensional penetration zone from bottom to top, forming a continuous multi-directional excitation on each layer of piezoelectric material. The pulsed water flow and the micro-nano bubbles formed by the micro-nano bubble aeration disc 11 form a counter-current cross-flow coupling in the reactor chamber 1, driving the piezoelectric catalytic reaction to achieve the degradation of pollutants in the water.

[0009] Furthermore, a water distribution plate 4 is provided below the top water inlet 2. The water distribution plate 4 is located between the top water inlet 2 and the two-dimensional turbulence zone. The water distribution plate 4 is fixedly installed on the inner wall of the reactor cavity 1. Several through holes are evenly distributed on the water distribution plate 4.

[0010] Furthermore, a film-like piezoelectric material layer 12 is provided in the two-dimensional agitation zone. The film-like piezoelectric material layer 12 is fixedly arranged in a horizontally laid manner inside the reactor cavity 1, and the membrane surface of the film-like piezoelectric material layer 12 is perpendicular to the water flow direction. The film-like piezoelectric material layer 12 is made of PVDF membrane material with a microporous structure. A fibrous or mesh-like piezoelectric material layer 13 is provided in the one-dimensional penetration zone. An adsorbent is loaded on the surface of the fibrous or mesh-like piezoelectric material layer 13. A granular piezoelectric material layer 14 is provided in the zero-dimensional fluidization zone. An escape-prevention interception net 16 and a lower limit support net 17 are respectively provided on the upper and lower sides of the granular piezoelectric material layer 14. The pore size of both the escape-prevention interception net 16 and the lower limit support net 17 is smaller than the particle diameter in the granular piezoelectric material layer 14. The escape-prevention interception net 16 is fixedly arranged above the granular piezoelectric material layer 14, and the lower limit support net 17 is fixedly arranged below the granular piezoelectric material layer 14.

[0011] Furthermore, the piezoelectric material in the film-like piezoelectric material layer 12, the fibrous or mesh-like piezoelectric material layer 13, and the particulate piezoelectric material layer 14 is PVDF material or PVDF composite material with a supported co-catalyst; the co-catalyst is selected from one or a combination of several of carbon-based nanomaterials, metal-organic frameworks (MOFs), transition metal compounds, and single-atom catalysts.

[0012] Furthermore, a piezoelectric catalytic degradation device for water pollutants further includes a gas-liquid regulation component; the gas-liquid regulation component is disposed between a two-dimensional agitation zone and a one-dimensional penetration zone; the gas-liquid regulation component includes a flow guide array 8, a flow guide plate fixing component 20, and a lateral exhaust valve 15; the flow guide plate fixing component 20 is fixed to the inner wall of the reactor cavity 1.

[0013] Furthermore, the flow guiding array 8 is composed of several inclined flow guiding plates. Each flow guiding plate is fixed to the inner wall of the reactor cavity 1 by the flow guiding plate fixing assembly 20. The flow guiding plates are arranged at a certain angle to the horizontal plane, and gaps are maintained between adjacent flow guiding plates to allow fluid to pass through.

[0014] Furthermore, the lateral exhaust valve 15 is disposed on the side wall of the reactor cavity 1, and the position of the lateral exhaust valve 15 corresponds to the inclined high end of the flow guide array 8.

[0015] The beneficial effects of this invention are: 1) This invention constructs a multi-dimensional cascade structure consisting of a two-dimensional agitation zone, a one-dimensional penetration zone, and a zero-dimensional fluidization zone. Each zone uses PVDF-based piezoelectric materials as the catalytic core and has piezoelectric filtration, piezoelectric adsorption degradation, and cavitation piezoelectric Fenton oxidation functions, forming a three-stage synergistic purification system of piezoelectric filtration, piezoelectric adsorption degradation, and cavitation piezoelectric Fenton oxidation, which is beneficial to improving the overall treatment efficiency of pollutants of different forms. 2) In this invention, the surface of the fibrous or mesh piezoelectric material layer 13 is loaded with adsorbent. After the pollutants are adsorbed and enriched, they are degraded in situ by the active free radicals generated by piezoelectric catalysis. The adsorption sites are then regenerated, forming an adsorption-degradation-regeneration closed loop, which is beneficial to extend the service life of the adsorbent and continuously enhance the catalytic degradation efficiency. 3) In this invention, the particulate piezoelectric material layer 14 adopts a core-shell structure composed of PVDF material and iron-based material, with piezoelectric electrons driving Fe. 3+ →Fe 2+ The recycling process, combined with the in-situ generated H2O2, forms a piezoelectric-Fenton coupling system, enabling the continuous recycling of iron, avoiding the problem of iron sludge accumulation in the traditional Fenton process, and improving the efficiency of deep oxidation degradation. 4) This invention regulates the movement path of bubbles by setting an inclined flow guide array 8, and discharges unbroken bubbles with the side exhaust valve 15, which effectively avoids gas resistance and prolongs the residence time of micro-nano bubbles, thus improving gas-liquid contact efficiency and piezoelectric excitation effect. 5) This invention mainly relies on fluid kinetic energy to drive the piezoelectric catalytic reaction, without relying on an external high-energy excitation source, and can achieve continuous operation in all weather conditions. The system has low energy consumption and is suitable for long-term stable engineering applications. 6) The present invention adopts a layered modular structure design, with the layers sealed and connected by a detachable buckle assembly 18. The catalyst material of each layer can be extracted and replaced independently, making maintenance convenient and helping to reduce the operation and maintenance cost of the device. Attached Figure Description

[0016] Appendix Figure 1 This is a schematic cross-sectional view of the overall structure of the present invention.

[0017] Appendix Figure 2 This is a partially enlarged structural diagram of the gas-liquid control component described in this invention.

[0018] Appendix Figure 3 This is a schematic diagram of the structure of different morphologies of piezoelectric materials in the multidimensional piezoelectric cascade catalytic region described in this invention.

[0019] Appendix Figure 4 This is a schematic diagram of the bubble fluidization excitation system and the zero-dimensional fluidization zone described in this invention.

[0020] Appendix Figure 5 This is a schematic diagram of the hydraulic pulse circulation drive system described in this invention.

[0021] In the attached diagram, 1 is the reactor chamber, 2 is the top inlet, 3 is the bottom outlet, 4 is the water distribution plate, 5 is the circulation pipe, 6 is the water pump, 7 is the pulse controller, 8 is the flow guide array, 9 is the air pump, 10 is the air inlet pipe, 11 is the micro-nano bubble aeration disc, 12 is the film-like piezoelectric material layer, 13 is the fibrous or mesh-like piezoelectric material layer, 14 is the granular piezoelectric material layer, 15 is the side exhaust valve, 16 is the escape prevention interception net, 17 is the lower limit support net, 18 is the detachable buckle assembly, 19 is the support base, and 20 is the flow guide plate fixing assembly. Detailed Implementation

[0022] A piezoelectric catalytic degradation device for water pollutants includes a reactor chamber 1; a top inlet 2 is provided at the top of the reactor chamber 1, and a bottom outlet 3 is provided at the bottom of the reactor chamber 1; the interior of the reactor chamber 1 is provided with a two-dimensional agitation zone, a one-dimensional penetration zone, a zero-dimensional fluidization zone, and a bubble fluidization excitation system; a hydraulic pulse circulation drive system is provided outside the reactor chamber 1, and the hydraulic pulse circulation drive system connects the top inlet 2 and the bottom outlet 3.

[0023] The two-dimensional agitation zone, one-dimensional penetration zone, zero-dimensional fluidization zone, and bubble fluidization activation system are arranged sequentially from top to bottom inside the reactor cavity 1; the two-dimensional agitation zone, one-dimensional penetration zone, and zero-dimensional fluidization zone are all constructed using PVDF (…). Jubilee Polyvinylidene fluoride membrane Using piezoelectric materials as the catalytic core, each material possesses different physicochemical purification functions and forms corresponding stress responses to different fluid disturbance modes.

[0024] The hydraulic pulse circulation drive system includes a circulation pipe 5, a water pump 6, and a pulse controller 7; the top water inlet 2 and the bottom water outlet 3 are connected through the circulation pipe 5, the water pump 6 is installed on the circulation pipe 5, and the pulse controller 7 is electrically connected to the water pump 6.

[0025] The bubble fluidization activation system includes a micro-nano bubble aeration disc 11, which is horizontally positioned below the zero-dimensional fluidization zone. The micro-nano bubble aeration disc 11 is connected to an air pump 9 outside the reactor cavity 1 via an air inlet pipe 10, which passes through the side wall of the reactor cavity 1. The surface of the micro-nano bubble aeration disc 11 is uniformly covered with micropores. During operation, the water pump 6 drives water to be drawn out through the bottom outlet 3 and then reintroduced into the top inlet 2 via the circulation pipe 5, forming a water circulation system. The pulse controller 7 is electrically connected to the water pump 6, and by periodically adjusting the start / stop frequency and flow rate of the water pump 6, the flow rate of water entering the reactor cavity 1 is controlled. The water flow forms a periodic variable-speed pulsed water flow, which is driven by the water pump 6 and the pulse controller 7 to form a pulsed water flow in the circulation pipe 5; the gas is sheared by the micro-nano bubble aeration disc 11 after being uniformly distributed with micro-pores to form micro-nano bubbles. The micro-nano bubbles pass through the zero-dimensional fluidization zone and the one-dimensional penetration zone from bottom to top, forming a continuous multi-directional excitation on each layer of piezoelectric material; the pulsed water flow and the micro-nano bubble flow formed by the micro-nano bubble aeration disc 11 form a reverse cross-flow coupling in the reactor cavity 1, which applies alternating stress to each layer of piezoelectric material in the one-dimensional penetration zone and the zero-dimensional fluidization zone, driving the piezoelectric catalytic reaction to achieve the degradation of water pollutants.

[0026] The periodic pulsed water flow from top to bottom creates axial hindrance to the upward motion of the bubbles: the axial upward velocity of the bubbles relative to reactor cavity 1, Ub,z, can be expressed as Ub,z = Uslip + Ul,z, where Uslip is the terminal slip velocity of the bubble and Ul,z is the average axial velocity of the liquid phase; under the continuous downward action of the pulsed water flow, Ul,z takes a negative value, and Ub,z decreases accordingly. The residence time of the bubbles in each catalytic zone is correspondingly extended, which is beneficial to enhancing the gas-liquid contact efficiency and piezoelectric excitation effect.

[0027] A water distribution plate 4 is provided below the top water inlet 2. The water distribution plate 4 is positioned between the top water inlet 2 and the two-dimensional turbulence zone. The water distribution plate 4 is fixedly installed on the inner wall of the reactor cavity 1. Several through holes are evenly distributed on the water distribution plate 4. During operation, the water flow generates transient velocity changes under the periodic regulation of the pulse controller 7. The fluid inertia and pressure wave superimposed in the circulation pipe 5 form a water hammer effect, which applies vertical impact stress to the film piezoelectric material layer 12 in the two-dimensional turbulence zone, driving the film surface to undergo periodic bending deformation and output piezoelectric potential. The periodic variable speed pulse water flow inside the circulation pipe 5 enters the reactor cavity 1 from the top water inlet 2 and is evenly dispersed by the water distribution plate 4 to form a uniformly distributed downward water flow. This is beneficial for the uniform force on each position of the film piezoelectric material layer 12 in the two-dimensional turbulence zone, while avoiding damage to the piezoelectric material caused by concentrated water flow impact. The water hammer effect is used to apply vertical impact stress to the two-dimensional turbulence zone.

[0028] The two-dimensional agitation zone contains a membrane piezoelectric material layer 12, which is horizontally laid out and fixed inside the reactor cavity 1. The membrane surface of the membrane piezoelectric material layer 12 is perpendicular to the water flow direction. The membrane piezoelectric material layer 12 is made of PVDF membrane material with a microporous structure, which has the dual functions of membrane filtration and piezoelectric catalysis. When water flows from top to bottom through the membrane surface of the membrane piezoelectric material layer 12, large molecular pollutants and suspended particles are physically trapped on the membrane surface due to the limitation of membrane pore size, thus achieving effective interception of large molecular pollutants in the water. The pollutants trapped on the membrane surface form a local high-concentration enrichment layer near the membrane surface, which significantly increases the probability of collision and contact with the active free radicals generated in situ. While trapping large molecular pollutants in the water, a piezoelectric potential is generated, realizing a synergistic enhancement effect of filtration and piezoelectric catalytic degradation, which is beneficial to improving the primary degradation efficiency.

[0029] The pulsed water flow, uniformly dispersed from top to bottom by the water distribution plate 4, impacts the membrane surface. Utilizing the water hammer effect, a two-dimensional bending vibration stress is generated within the plane of the piezoelectric membrane layer 12, causing periodic bending deformation of the piezoelectric membrane material. Under the bending stress, the β-phase crystal form of the PVDF membrane material exhibits ordered arrangement of dipole moments along the stress direction, forming a piezoelectric potential difference across the membrane and establishing a built-in electric field. This drives the directional separation of charge carriers within the material: conduction band electrons react with dissolved oxygen in the water to generate superoxide anion free radicals (·O2). - The valence band hole reacts with water molecules to generate hydroxyl radicals (·OH), and ·OH reacts with ·O2. - The synergistic effect allows for the initial oxidation and degradation of pollutants trapped and enriched on the membrane surface; the mechanical disturbance generated by piezoelectric vibration also helps to alleviate membrane fouling and extend the effective service life of the membrane.

[0030] The one-dimensional penetration zone is provided with a fibrous or mesh-like piezoelectric material layer 13, which is arranged in a certain direction and fixed inside the reactor cavity 1. The surface of the fibrous or mesh-like piezoelectric material layer 13 is loaded with an adsorbent, which is selected from one or a combination of carbon-based nanomaterials or metal-organic frameworks (MOFs). During operation, the adsorbent loaded on the surface of the fibrous or mesh-like piezoelectric material layer 13 enriches dissolved pollutants. The enriched pollutants are degraded in situ by active free radicals generated by piezoelectric catalysis. The adsorption sites are released and regenerated, forming a closed loop of adsorption enrichment-in-situ degradation-site regeneration, which is beneficial to extend the service life of the adsorbent and continuously enhance the catalytic degradation efficiency.

[0031] Regarding the adsorption enrichment and in-situ regeneration mechanism, carbon-based nanomaterials or metal-organic frameworks (MOFs) enrich dissolved pollutants in water onto the material surface through π-π stacking, electrostatic attraction, and pore confinement, forming a locally high-concentration adsorption layer. This compresses the interfacial distance between the pollutants and the active free radicals generated in-situ by piezoelectric catalysis to the molecular scale. The adsorption enrichment concentration can be increased by several orders of magnitude compared to the bulk solution concentration, thus significantly improving the free radical utilization efficiency, which is beneficial for achieving efficient and deep degradation of low-concentration dissolved pollutants. The pollutants enriched on the adsorbent surface undergo high-concentration regeneration under piezoelectric catalysis. Oxidative degradation occurs under in-situ attack by free radicals, and pollutant molecules are decomposed into small molecule products or completely mineralized. The adsorption sites are released and regenerated accordingly. The regenerated adsorption sites continue to adsorb and enrich new pollutant molecules in the solution, driving the closed-loop operation of adsorption enrichment-in-situ degradation-site regeneration. This closed-loop mechanism significantly extends the service life of the adsorbent compared to traditional simple adsorption processes. In traditional adsorption processes, the adsorbent needs to be replaced as a whole once it is saturated. However, in this invention, the adsorption sites are continuously regenerated in situ through piezoelectric catalysis, which helps to reduce operation and maintenance costs and maintain a continuous and stable adsorption and purification capacity.

[0032] Regarding the multidirectional composite stress polarization mechanism, the one-dimensional penetration region is located at the counter-current intersection of the top-down pulsed water flow and the bottom-up micro-nano bubble flow. The gas and liquid phases simultaneously apply multidirectional alternating stress to the fibrous or mesh piezoelectric material layer 13. When the fluid penetrates the fiber or mesh gaps, tensile and compressive alternating stresses are generated along the fiber axis, exciting the d33 axial polarization mode of the PVDF material. When bubbles penetrate the mesh, they collide with and rupture against the fibers or mesh material, and the rupture impact force acts laterally on the material, exciting the d31 in-plane polarization mode. Both polarization modes occur simultaneously on the same material. In the superposition, the beta phase CF dipole moments are ordered in both the axial and in-plane directions, and the piezoelectric potential output amplitude is more favorable than that excited by any single stress direction. The formation of this dual-mode composite polarization state requires a gas-liquid reverse crossflow structure as a necessary prerequisite. A single pulse water flow device can only excite d31 polarization, and a single aeration device can only excite d33 polarization. Neither of them can generate a synchronous composite stress state of axial tension and transverse impact on the fiber material when they operate independently. The reverse crossflow structure of this invention is an irreplaceable structural condition for realizing this dual-mode superposition.

[0033] The fiber surface of the fibrous or mesh-like piezoelectric material layer 13 is surface functionalized to have aerophilic properties. When micro-nano bubbles reach the fiber surface, the gas-liquid-solid three-phase contact causes a pinning effect on the aerophilic fiber surface, and the bubbles are captured and retained on the fiber surface, thus constructing a gas-liquid-solid three-phase micro-reaction interface in situ. At this gas-liquid-solid three-phase micro-reaction interface, the local dissolved oxygen concentration of high-pressure oxygen in the bubbles towards the liquid phase is higher than that of the bulk solution, and OH⁻ is relatively enriched at the interface. The two work together to improve the generation efficiency of superoxide anion free radicals at the interface. The impact energy released when the bubbles burst directly acts on the fiber surface, stimulating piezoelectric catalysis in situ, realizing the in-situ conversion of bubble kinetic energy, and reducing the dissipation loss of impact energy propagating in the liquid phase.

[0034] Regarding the construction mechanism of the gas-liquid-solid three-phase micro-reaction interface, the surface of the fibrous or mesh-like piezoelectric material layer 13 is hydrophobic and gas-philic. When the bubble reaches the fiber surface, the gas-liquid-solid three-phase contact undergoes a pinning effect, and the bubble is retained on the fiber surface, thus constructing the gas-liquid-solid three-phase micro-reaction interface in situ. At this gas-liquid-solid three-phase micro-reaction interface, the local dissolved oxygen concentration of high-pressure oxygen inside the bubble towards the liquid phase side of the interface is significantly higher than that of the bulk solution, and the OH- concentration at the interface is relatively enriched. The synergy of these two factors is conducive to improving the efficiency of superoxide anion free radical generation at the interface. At the same time, the impact energy released when the bubble bursts directly acts on the fiber surface, in-situ stimulating piezoelectric catalysis near the interface, realizing the in-situ conversion and utilization of the bubble's mechanical energy. This helps to reduce the dissipation loss of impact energy propagating in the liquid phase, enabling a higher proportion of the bubble's kinetic energy to be converted into piezoelectric potential and active free radicals.

[0035] The one-dimensional penetration zone is located at the confluence of the downward-flowing pulsed water flow and the upward-flowing micro-nano bubble flow, where the gas and liquid phases apply multi-directional alternating stress to the fibrous or mesh piezoelectric material layer 13. During the process of the fluid penetrating the gaps between the fibers or mesh, the fluid creates alternating tensile and compressive stresses along the fiber axis. When bubbles penetrate the mesh, they collide with and rupture against the fibers or mesh, and the resulting impact force acts laterally on the material, causing the fibrous or mesh piezoelectric material layer 13 to simultaneously bear the multi-directional superposition of axial tensile and compressive stresses and lateral impact stresses. Specifically, the d33 axial polarization mode of the PVDF material is excited. When bubbles penetrate the mesh, they collide with and rupture against the fibers or mesh, and the rupture impact force acts laterally on the material, exciting the d31 in-plane polarization mode. The two polarization modes are simultaneously superimposed on the same material, and the β-phase CF dipole moments are orderly arranged in both the axial and in-plane directions. The piezoelectric potential output amplitude is higher than that excited by any single stress direction, achieving deep degradation of dissolved pollutants.

[0036] The zero-dimensional fluidized region is provided with a particulate piezoelectric material layer 14; the particles in the particulate piezoelectric material layer 14 adopt a core-shell structure, including a rigid supporting core and a piezoelectric composite shell composed of PVDF material and iron-based material.

[0037] The iron-based material is a commercially available iron-based material in the field, including any one or a combination of Fe3O4, alpha-Fe2O3, zero-valent iron, etc., which can be selected according to actual needs; the rigid support core provides sufficient mechanical strength for the particles, which is conducive to maintaining the structural integrity of the particles during fluidized collision; the piezoelectric composite shell is composed of PVDF material and iron-based material, which generates piezoelectric effect when subjected to impact stress and drives the valence state transformation of iron in the iron-based material; the particles form a fluidized state in the zero-dimensional fluidization region under the impact of micro-nano bubbles and water flow disturbance, and random collisions occur between particles and between particles and bubbles. The collision points are distributed at various points on the particle surface, generating multi-directional local stress and realizing multi-directional excitation at the zero-dimensional scale.

[0038] Regarding the mechanism of particle fluidization and omnidirectional stress excitation, particles form a fluidized state in the zero-dimensional fluidization region under the impact of micro- and nano-bubbles and the disturbance of water flow. Random collisions occur between particles and between particles and bubbles. The collision points are statistically uniformly distributed throughout the particle surface, generating isotropic three-dimensional volumetric stress. While exciting the d33 axial polarization mode, it also has the d31 in-plane polarization component, which is conducive to achieving more complete beta phase polarization excitation than unidirectional stress, making the piezoelectric potential output approach the maximum value. The high degree of freedom of particle motion is the core feature that distinguishes zero-dimensional structures from film and fibrous fixed materials: film and fibrous materials are constrained by the structure due to fixed installation, while particle materials can rotate and collide freely in three-dimensional space in the fluidized state. The direction of the force in each collision is random, thus achieving true omnidirectional stress excitation in the sense of time integration. This characteristic is not possessed by film and fibrous fixed materials.

[0039] In terms of the cavitation mechanism, micro- and nano-bubbles are geometrically confined within the interparticle gaps, and the cavitation effect generated during bubble collapse is more significant than in open spaces: the geometric constraint of the interparticle gaps increases the local pressure peak during bubble collapse, instantly creating a local extreme environment. Under extreme conditions, water molecules undergo homolytic cleavage to directly generate hydroxyl radicals, with the reaction formula H2O = ·OH + ·H. This process does not rely on piezoelectric potential and can independently contribute to the source of hydroxyl radicals. The spatial constraint of the bubble collapse location by the interparticle gaps is conducive to concentrating the release of cavitation energy near the particle surface, allowing the hydroxyl radicals generated by cavitation to directly act on residual pollutants near the particle surface, reducing the diffusion loss of free radicals in the liquid phase and improving the effective utilization rate of free radicals.

[0040] Regarding the piezoelectric-Fenton coupling mechanism, particle collisions excite the PVDF piezoelectric composite shell to generate a piezoelectric potential, establishing a built-in electric field that drives the directional separation of charge carriers. The separated piezoelectric electrons are efficiently captured by the empty d orbitals of the transition metal in the iron-based material. The capture efficiency of empty d orbitals for electrons is significantly higher than that of general conductor interfaces, which can greatly reduce the charge transfer barrier and drive the valence state transformation of iron. The reaction formula is Fe 3+ + e- = Fe 2+ To achieve Fe 3+ / Fe 2+ Recycling and regeneration; regenerated Fe 2+ Together with H2O2 generated in situ from the in-situ reduction of dissolved oxygen by piezoelectric electrons, they form a piezoelectric-Fenton coupling system, with the reaction equations being O2 + 2H2O and H2O, respectively. + + 2e- = H2O2 and Fe 2+ + H2O2= Fe 3+ + ·OH + OH- continuously generate hydroxyl radicals to deeply oxidize and degrade residual pollutants; in this coupled system, Fe 3+ / Fe2+ The cycle is self-driven by a piezoelectric process, requiring no external reducing agent. Iron ions continuously exert a catalytic effect in the closed cycle, effectively avoiding the drawbacks of the traditional Fenton process due to Fe. 2+ The problem of secondary pollution caused by continuous consumption and the accumulation of iron sludge.

[0041] Regarding the structural dependence of the triple synergistic effect, the synergistic superposition of cavitation, piezoelectric catalysis, and Fenton oxidation in the zero-dimensional fluidized zone has a clear structural premise. All three depend on the micro-reaction environment in which core-shell particles and bubbles coexist in the interparticle gaps. The triple synergistic state cannot be achieved without any structural element. The cavitation effect depends on the confined collapse of micro- and nano-bubbles in the interparticle gaps. Without the interparticle layer gap constraint, the cavitation intensity is greatly reduced when bubbles collapse in the open liquid phase. The piezoelectric-Fenton coupling depends on the direct solid-phase contact conduction between piezoelectric electrons and iron-based materials. If the iron-based materials and PVDF materials are arranged separately, the piezoelectric electrons must be conducted through the liquid phase. Since the liquid phase resistance is much higher than that of the solid phase, the charge transfer efficiency is greatly reduced. When the three occur simultaneously on the same core-shell particle surface, the hydroxyl radicals generated by each mechanism are highly enriched and superimposed near the particle surface. The synergistic oxidation efficiency is much higher than the sum of the individual effects of each mechanism, which is conducive to the deep mineralization of residual recalcitrant pollutants in the zero-dimensional fluidized zone.

[0042] The granular piezoelectric material layer 14 is provided with an escape-prevention interception net 16 and a lower limit support net 17 on its upper and lower sides, respectively. The aperture of both the escape-prevention interception net 16 and the lower limit support net 17 is smaller than the particle diameter in the granular piezoelectric material layer 14, which confines the particles within the zero-dimensional fluidization region, ensuring the independence and stability of the functional regions of each catalytic material layer. The escape-prevention interception net 16 is fixedly set above the granular piezoelectric material layer 14 to prevent particles from escaping into the one-dimensional penetration region with the rising flow of bubbles. The lower limit support net 17 is fixedly set below the granular piezoelectric material layer 14 to prevent particles from settling into the micro-nano bubble aeration disk 11 area, ensuring that the particles are stably fluidized within the zero-dimensional fluidization region, and ensuring the independence and stability of the functional regions of each catalytic material layer.

[0043] During operation, the collapse of micro- and nano-bubbles within the zero-dimensional fluidization region generates cavitation, instantly creating a localized high-temperature and high-pressure environment. Under extreme conditions, water molecules undergo homolytic cleavage to generate ·OH, directly participating in the oxidative degradation of residual pollutants. Simultaneously, particle collisions excite the PVDF piezoelectric composite shell to generate a piezoelectric potential. Piezoelectric electrons are conducted through the iron-based material, transferring Fe... 3+ Reduced to Fe 2+ This achieves the recycling and regeneration of iron; the regenerated Fe 2+ The H2O2 generated in situ by the piezoelectric reduction of dissolved oxygen forms a piezoelectric-Fenton coupling system, continuously generating ·OH to deeply oxidize and degrade residual pollutants; in this coupling system, iron ions are piezoelectrically driven to achieve Fe 3+ / Fe2+ The recycling process effectively avoids the secondary pollution problem caused by the accumulation of iron sludge in the traditional Fenton process; the synergistic effect of cavitation, piezoelectric catalysis and Fenton oxidation is conducive to the complete mineralization of residual pollutants.

[0044] The piezoelectric materials in the film-like piezoelectric material layer 12, the fibrous or mesh-like piezoelectric material layer 13, and the granular piezoelectric material layer 14 are PVDF materials or PVDF composite materials with supported co-catalysts. PVDF (polyvinylidene fluoride) is an organic piezoelectric polymer with piezoelectric properties. When its β-phase crystal form deforms under external force, it can generate charge accumulation on the material surface. The CF bond dipole moments are arranged in an orderly manner along the stress direction, generating charge accumulation on the material surface and forming a piezoelectric potential, which is beneficial for driving the catalytic reaction. Compared with inorganic piezoelectric materials, PVDF materials have better flexibility and are easy to process into various forms such as film, fiber, and granules, which are suitable for the construction requirements of the multidimensional piezoelectric cascade structure of this invention. The co-catalyst is selected from one or a combination of carbon-based nanomaterials, metal-organic frameworks (MOFs), transition metal compounds, and single-atom catalysts. The co-catalyst is loaded on the surface of the PVDF material, which is beneficial for improving the catalytic activity of the piezoelectric material and the generation efficiency of active free radicals, and further enhancing the degradation effect on water pollutants.

[0045] A piezoelectric catalytic degradation device for water pollutants, the structure of which further includes a gas-liquid regulation component; the gas-liquid regulation component is disposed between a two-dimensional agitation zone and a one-dimensional penetration zone; the gas-liquid regulation component includes a flow guide array 8, a flow guide plate fixing component 20, and a lateral exhaust valve 15; the flow guide plate fixing component 20 is fixed to the inner wall of the reactor cavity 1, and the flow guide plate fixing component 20 is used to support and fix the flow guide array 8 to ensure that the flow guide array 8 maintains a stable tilt angle during device operation.

[0046] The flow guiding array 8 consists of several inclined flow guiding plates. Each flow guiding plate is fixed to the inner wall of the reactor cavity 1 by the flow guiding plate fixing assembly 20. The flow guiding plates are arranged at a certain angle to the horizontal plane, preferably at an angle of 20° to 45°. A gap is maintained between adjacent flow guiding plates to allow fluid to pass through. When the micro-nano bubbles moving from bottom to top reach the flow guiding array 8, they are obliquely intercepted by the inclined flow guiding plates. The bubble movement path changes from vertical upward to non-linear movement along the inclined plane, which prolongs the residence time of the bubble in the one-dimensional penetration zone and increases the contact area between the bubble and the fiber or mesh material. This is beneficial for the impact energy released when the bubble breaks to be fully transferred to the piezoelectric material.

[0047] The guide vanes are further preferably arranged at a 30° angle to the horizontal plane, with gaps remaining between adjacent guide vanes for fluid passage. Through optimization analysis, a 30° tilt angle achieves the best balance between the bubble path extension effect, the degree of axial velocity suppression, and fluid resistance: compared to a larger tilt angle, a 30° tilt angle reduces the axial velocity of the bubbles by a greater extent (by 50%), resulting in a more significant bubble retention effect; compared to a smaller tilt angle, a 30° tilt angle still ensures the non-linear movement path of the bubbles along the inclined plane and the effective contact sweep area with the guide vanes, while avoiding excessive fluid resistance due to an excessively small tilt angle, which would affect the overall hydraulic performance of the device. Therefore, 30° is the optimal tilt angle value for the guide array 8 of this invention.

[0048] Regarding the geometric mechanism of bubble path extension, when the micro-nano bubbles moving from bottom to top reach the flow guide array 8, they are obliquely intercepted by the inclined flow guides, and the direction of bubble movement changes from vertical upward to non-linear movement along the inclined plane. Taking the inclined angle theta of the flow guide as 30° and the horizontal projection width of the flow guide as W as an example, the actual movement path length of the bubble along the inclined plane is Lpath = W / cos(theta). When theta is 30°, Lpath is about 1.15W. The actual movement path of the bubble is about 15% longer than the vertical crossing path within the same horizontal distance. The contact sweep area between the bubble and the surface of each flow guide is Scontact = n × Lpath × db, where n is the number of flow guides that the bubble crosses and db is the equivalent diameter of the bubble. The oblique movement significantly increases the contact area compared to the end point contact during vertical crossing, which is beneficial for the impact energy released when the bubble breaks to be fully transferred to the fibrous or mesh piezoelectric material layer 13.

[0049] Regarding the hydrodynamic mechanism of bubble axial velocity suppression, the bubble is continuously constrained by the guide plate on the inclined plane, and its equivalent axial upward velocity is reduced to Ub,z,eff = Ub,zx sin(theta). When theta is 30°, the axial upward velocity is reduced by 50% compared with the free upward state, and the residence time of the bubble in the guide zone is correspondingly extended. This suppression effect is superimposed with the axial obstruction effect of the pulsed water flow on the bubble, which together prolongs the effective contact time of the bubble in the one-dimensional penetration zone and the guide zone, enhances the frequency of collision and rupture events between the bubble and the fibrous or mesh piezoelectric material layer 13, and thus improves the piezoelectric excitation effect. The bubbles that fail to rupture in the guide zone converge along the inclined plane and are discharged from the reactor cavity 1 through the lateral exhaust valve 15, realizing a balanced design of controllable retention and prevention of gas resistance, avoiding the accumulation of gas affecting the smooth counter-current movement of the pulsed water flow and the micro-nano bubble flow in the reactor cavity 1.

[0050] The lateral exhaust valve 15 is located on the side wall of the reactor cavity 1. The position of the lateral exhaust valve 15 corresponds to the inclined high end of the flow guide array 8. Bubbles that fail to break in the one-dimensional penetration zone converge along the inclined surface of the flow guide array 8 and are discharged from the reactor cavity 1 through the lateral exhaust valve 15, thus avoiding the accumulation of gas and forming gas resistance, and ensuring the smooth counter-current movement of the pulse water flow and the micro-nano bubble flow in the reactor cavity 1.

[0051] The reactor chamber 1 is equipped with a support base 19 at its bottom. The reactor chamber 1 shell is vertically divided into several independent sections, which are sealed together by detachable fastening components 18 to prevent short circuits between the sections and facilitate independent disassembly and replacement of each catalytic material layer. This allows for drawer-style independent disassembly and assembly of the two-dimensional agitation zone, one-dimensional penetration zone, and zero-dimensional fluidization zone. When a catalytic material layer needs to be replaced or maintained, the detachable fastening component 18 of the corresponding section is loosened, and the section is pulled out along the guide groove. The corresponding film-like piezoelectric material layer 12, fibrous or mesh-like piezoelectric material layer 13, and granular piezoelectric material layer 14 are then removed and replaced. After replacement, the section is pushed back in and the detachable fastening component 18 is fastened to restore operation. The entire disassembly and assembly process is simple to operate, which helps reduce the operation and maintenance costs of the device and is suitable for long-term stable engineering applications.

[0052] The reactor chamber 1 is a vertically arranged cylindrical container made of corrosion-resistant material.

[0053] When the device of this invention is running, the water to be treated enters the reactor chamber 1 through the top inlet 2. The hydraulic pulse circulation drive system and the bubble fluidization excitation system respectively form a periodic pulse water flow from top to bottom and a micro-nano bubble flow from bottom to top. The two form a counter-current coupling within the reactor chamber 1. The two-dimensional turbulence zone, the one-dimensional penetration zone, and the zero-dimensional fluidization zone together form a multi-dimensional piezoelectric cascade catalytic zone, which generates alternating stress excitation on each layer of PVDF-based piezoelectric material in the multi-dimensional piezoelectric cascade catalytic zone, driving the piezoelectric material to generate a piezoelectric potential and generate active free radicals. The water is sequentially purified through three stages of piezoelectric filtration interception, piezoelectric adsorption degradation, and cavitation piezoelectric Fenton oxidation, achieving cascade synergistic degradation of pollutants of different forms. The water treated by the multi-dimensional piezoelectric cascade catalytic zone is discharged through the bottom outlet 3, completing the catalytic water treatment process.

[0054] The water flow undergoes a three-stage purification process: piezoelectric filtration, piezoelectric adsorption degradation, and cavitation piezoelectric Fenton oxidation. Specifically, in the two-dimensional agitation zone, a film-like piezoelectric material layer 12 traps macromolecular pollutants and generates a piezoelectric potential, with in-situ active free radicals performing preliminary degradation on the trapped pollutants. In the one-dimensional penetration zone, the adsorbent enriches dissolved pollutants and then undergoes in-situ degradation via piezoelectric catalysis, with continuous regeneration of adsorption sites. In the zero-dimensional fluidization zone, cavitation impact excites the piezoelectric-Fenton coupling system for deep oxidation and degradation of residual pollutants. The treated water is then discharged through the bottom outlet 3.

[0055] In this invention, a three-dimensional purification system is constructed, consisting of a two-dimensional turbulence zone, a one-dimensional penetration zone, and a zero-dimensional fluidization zone. Within this system, each zone exhibits a close upstream and downstream material flow connection and interfacial chemical coupling mechanism. The overall purification efficiency generated by the synergistic effect of the three-dimensional purification system differs from the simple summation of the individual zone's effects. The spatial cascade arrangement of the three-dimensional purification system creates a structural synergistic effect that no individual functional zone possesses—the membrane retention in the two-dimensional turbulence zone provides irreplaceable protection for the downstream adsorption capacity, a protection determined by its upstream structural position, an effect that no single membrane or adsorption layer can produce. The gas-liquid countercurrent cross-flow structure simultaneously generates d33 and d31 dual-mode composite polarization on the fiber material in the one-dimensional penetration zone. This dual-mode superposition is physically impossible to achieve with a single pulse device or a single aeration device. In the zero-dimensional fluidization zone, the direct solid-phase contact between the PVDF in the core-shell particles and the iron-based material enables efficient piezoelectric electron conduction and Fe... 3+ / Fe 2+ The cyclic regeneration process allows cavitation, piezoelectric catalysis, and Fenton oxidation to occur simultaneously on the same particle surface, resulting in a triple synergistic oxidation efficiency that far exceeds the sum of the individual effects of each mechanism.

[0056] The three-stage purification system of this invention generates a synergistic effect mechanism at four levels during the overall operation, constituting a piezoelectric catalytic degradation device for water pollutants with multi-dimensional piezoelectric cascade and gas-liquid cross-flow synergy.

[0057] First, the cascaded guidance of material flow and the synergistic effect of site protection: the two-dimensional agitation zone traps and initially breaks bonds of macromolecular pollutants, eliminating steric hindrance for adsorption and enrichment in the one-dimensional penetration zone, allowing the adsorbent channels to preferentially capture intermediate products and soluble pollutants with suitable molecular weights; the in-situ degradation products after adsorption and enrichment in the one-dimensional penetration zone enter the zero-dimensional fluidization zone in the form of small molecules, which are more easily mineralized by the piezoelectric-Fenton system; the relay relationship of upstream and downstream material flow ensures that each zone always treats the most suitable pollutant form, and the catalytic efficiency of each zone is in a relatively optimal state; if the three zones operate independently, each zone must face mixed pollutant forms, the blockage effect of macromolecules on adsorption sites will continuously weaken the efficiency of the one-dimensional zone, and the upstream and downstream synergistic protection mechanism will also disappear, and the overall efficiency will inevitably be lower than that of the cascade synergistic state.

[0058] Second, the spatial enrichment and precise matching of active free radicals work synergistically. The active free radicals generated in the two-dimensional agitation zone preferentially act on high-concentration macromolecular pollutants trapped on the membrane surface. The membrane surface trapping and enrichment effect makes the interfacial contact probability between free radicals and pollutants significantly higher than the random collision probability in the bulk solution. The active free radicals generated in the one-dimensional penetration zone act on the adsorption and enrichment of medium-concentration soluble pollutants on the fiber surface. The adsorption and enrichment effect also significantly improves the utilization efficiency of free radicals. The zero-dimensional fluidization zone forms an extremely high local free radical concentration near the particle surface through the cavitation-piezoelectric-Fenton triple mechanism, specifically targeting the low-concentration recalcitrant residual pollutants remaining after the first two stages of treatment. The free radical generation positions and the corresponding spatial enrichment positions of pollutants in the three regions achieve a step-by-step precise matching, forming a cascade amplification effect of high-concentration free radicals acting on high-concentration pollutants. A single functional layer cannot simultaneously optimize the spatial distribution of free radicals for the needs of three different concentration forms: macromolecular trapping, soluble enrichment, and recalcitrant deep mineralization.

[0059] Third, the multidimensional superposition and synergy of piezoelectric polarization modes; the two-dimensional oscillation region mainly excites the d31 in-plane polarization mode, the one-dimensional penetration region simultaneously excites the d33 and d31 dual-mode composite polarization, and the zero-dimensional fluidization region realizes isotropic omnidirectional polarization excitation—the three polarization modes are spatially connected in series within the same device, and the overall beta phase polarization degree and the cumulative generation of active free radicals are conducive to exceeding the level of any single polarization mode device; it is particularly worth noting that the realization of the simultaneous superposition of the d33 and d31 dual modes in the one-dimensional penetration region depends on the gas-liquid countercurrent crossflow structure to simultaneously generate axial tensile and transverse impact stresses on the fiber material. This is a systematic product of the overall device structural design, and neither a single pulse drive device nor a single aeration device can simultaneously generate this dual-mode composite polarization state on the same material.

[0060] Fourth, the multi-stage confinement and synergistic conversion of bubble energy: After the bubble is generated from the micro-nano bubble aeration disc 11, it undergoes three stages of effective energy conversion: fluidization excitation due to particle gap confinement, collision and rupture at the gas-liquid-solid three-phase interface in the one-dimensional penetration zone, and oblique interception by the flow guide array 8 to extend the contact path. Particle gap confinement increases the cavitation intensity during bubble collapse; the three-phase interface pinning effect causes the impact energy of bubble collapse to act on the piezoelectric material on the fiber surface in situ; the flow guide array 8 extends the effective contact time of the bubble in the catalytic zone; relying on the synergistic effect of the spatial arrangement of each structural unit, the kinetic energy of the bubble from generation to discharge is effectively converted into piezoelectric excitation energy and cavitation oxidation energy. The effective conversion rate of bubble energy is significantly higher than the result of any single-stage confinement structure acting alone due to the superposition of the confinement effects of the three stages.

Claims

1. A piezoelectric catalytic degradation device for water pollutants, characterized in that: The reactor includes a reactor cavity (1); the top of the reactor cavity (1) is provided with a top inlet (2) and the bottom of the reactor cavity (1) is provided with a bottom outlet (3); the reactor cavity (1) has a two-dimensional agitation zone, a one-dimensional penetration zone, a zero-dimensional fluidization zone, and a bubble fluidization activation system distributed inside the cavity; the reactor cavity (1) is provided with a hydraulic pulse circulation drive system outside the cavity, and the hydraulic pulse circulation drive system connects the top inlet (2) and the bottom outlet (3).

2. The piezoelectric catalytic degradation device for water pollutants according to claim 1, characterized in that: The two-dimensional turbulence zone, one-dimensional penetration zone, zero-dimensional fluidization zone, and bubble fluidization activation system are arranged sequentially from top to bottom inside the reactor cavity (1).

3. The piezoelectric catalytic degradation device for water pollutants according to claim 1, characterized in that: The hydraulic pulse circulation drive system includes a circulation pipe (5), a water pump (6), and a pulse controller (7); the top inlet (2) and the bottom outlet (3) are connected through the circulation pipe (5), the water pump (6) is installed on the circulation pipe (5), and the pulse controller (7) is electrically connected to the water pump (6).

4. The piezoelectric catalytic degradation device for water pollutants according to claim 1, characterized in that: The bubble fluidization activation system includes a micro-nano bubble aeration disc (11), which is horizontally positioned below the zero-dimensional fluidization zone. The micro-nano bubble aeration disc (11) is connected to an air pump (9) outside the reactor cavity (1) via an air inlet pipe (10). The air inlet pipe (10) passes through the side wall of the reactor cavity (1). During operation, the water pump (6) drives the water to be drawn out through the bottom outlet (3) and then sent back into the top inlet (2) through the circulation pipe (5), forming a water internal circulation. The pulse controller (7) is electrically connected to the water pump (6) and periodically adjusts the start-up of the water pump (6). The frequency and flow rate are adjusted to form a periodic variable-speed pulse water flow in the reactor cavity (1). Driven by the water pump (6) and the pulse controller (7), a pulse water flow is formed in the circulation pipe (5). Gas forms micro-nano bubbles on the surface of the micro-nano bubble aeration disc (11). The micro-nano bubbles pass through the zero-dimensional fluidization zone and the one-dimensional penetration zone from bottom to top, forming a continuous multi-directional excitation on each layer of piezoelectric material. The pulse water flow and the micro-nano bubbles formed by the micro-nano bubble aeration disc (11) form a reverse cross-flow coupling in the reactor cavity (1), driving the piezoelectric catalytic reaction to achieve the degradation of water pollutants.

5. The piezoelectric catalytic degradation device for water pollutants according to claim 1, characterized in that: A water distribution plate (4) is provided below the top water inlet (2). The water distribution plate (4) is located between the top water inlet (2) and the two-dimensional turbulence zone. The water distribution plate (4) is fixedly installed on the inner wall of the reactor cavity (1). Several through holes are evenly distributed on the water distribution plate (4).

6. The piezoelectric catalytic degradation device for water pollutants according to claim 1, characterized in that: The two-dimensional agitation zone contains a film-like piezoelectric material layer (12), which is fixedly arranged in a horizontally laid manner inside the reactor cavity (1), with the membrane surface of the film-like piezoelectric material layer (12) perpendicular to the water flow direction; the film-like piezoelectric material layer (12) is made of PVDF membrane material with a microporous structure; the one-dimensional penetration zone contains a fibrous or mesh-like piezoelectric material layer (13); the surface of the fibrous or mesh-like piezoelectric material layer (13) is loaded with an adsorbent; the zero-dimensional fluidization zone contains... A granular piezoelectric material layer (14) is provided; an escape-proof interception net (16) and a lower limit support net (17) are respectively provided on the upper and lower sides of the granular piezoelectric material layer (14). The aperture of both the escape-proof interception net (16) and the lower limit support net (17) is smaller than the particle diameter in the granular piezoelectric material layer (14); the escape-proof interception net (16) is fixedly set above the granular piezoelectric material layer (14), and the lower limit support net (17) is fixedly set below the granular piezoelectric material layer (14).

7. The piezoelectric catalytic degradation device for water pollutants according to claim 6, characterized in that: The piezoelectric materials in the film-like piezoelectric material layer (12), the fibrous or mesh-like piezoelectric material layer (13), and the particulate piezoelectric material layer (14) are PVDF materials or PVDF composite materials with supported catalysts; the catalysts are selected from one or a combination of several of carbon-based nanomaterials, metal-organic frameworks (MOFs), transition metal compounds, and single-atom catalysts.

8. The piezoelectric catalytic degradation device for water pollutants according to claim 1, characterized in that: It also includes a gas-liquid control component; the gas-liquid control component is disposed between the two-dimensional turbulence zone and the one-dimensional penetration zone; the gas-liquid control component includes a flow guide array (8), a flow guide plate fixing component (20), and a side exhaust valve (15); the flow guide plate fixing component (20) is fixed to the inner wall of the reactor cavity (1).

9. The piezoelectric catalytic degradation device for water pollutants according to claim 8, characterized in that: The flow guide array (8) consists of several inclined flow guide plates. Each flow guide plate is fixed to the inner wall of the reactor cavity (1) by a flow guide plate fixing assembly (20). The flow guide plates are arranged at a certain angle to the horizontal plane, and a gap is maintained between adjacent flow guide plates for fluid to pass through.

10. The piezoelectric catalytic degradation device for water pollutants according to claim 8, characterized in that: The lateral exhaust valve (15) is located on the side wall of the reactor cavity (1), and the position of the lateral exhaust valve (15) corresponds to the inclined high end of the flow guide array (8).

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