Method and device for synchronously degrading organic pollutants through wastewater rotational flow piezoelectric hydrogen production

Abstract

The invention discloses a method and a device for synchronously degrading organic pollutants through wastewater rotational flow piezoelectric hydrogen production, which are characterized in that a catalytic system is uniformly distributed in organic wastewater to form a first solid-liquid mixed system, and the first solid-liquid mixed system is introduced into a hydraulic rotational flow reactor along the tangential direction at a high speed to form a second solid-liquid mixed system; a strong three-dimensional rotating flow field is formed in the hydraulic cyclone reactor, and mechanical stress is provided for an advanced oxidation technology coupling piezoelectric catalysis system, so that the piezoelectric effect is continuously excited to generate hydrogen, and meanwhile, the wastewater is deeply treated; experiments prove that the device and the method provided by the invention realize high-efficiency hydrogen production under the conditions of low energy consumption, low cost and simple operation, and synchronously complete high-efficiency degradation of organic pollutants in wastewater.

Description

Technical Field

[0001] The present invention belongs to the technical fields of wastewater treatment and piezoelectric hydrogen production, and specifically relates to a method and device for synchronously degrading organic pollutants while producing hydrogen by wastewater swirling and piezoelectric effect. Background Art

[0002] Facing a series of climate problems brought about by global warming and a large amount of greenhouse gas emissions, it is imperative to develop low-carbon, clean, and sustainable energy to achieve carbon neutrality. Hydrogen energy has the characteristic of high calorific value and has become an inevitable trend in the future energy development. It is zero-pollution and environmentally friendly, thus greatly promoting the process of carbon neutrality.

[0003] Hydrogen energy has the dual attributes of resources and energy, and is an important carrier for realizing the replacement of fossil energy, building the country's future energy system, and supporting the green and low-carbon transformation of the energy consumption side under the background of carbon neutrality.

[0004] Green hydrogen is the focus of competition in the new round of world scientific and technological revolution and industrial transformation, and is an important support for ensuring national energy security and supporting high-quality economic development. However, there are still core bottleneck problems in the hydrogen energy field in China, such as "the hydrogen production route is not green enough, the scale is not large enough, and the cost is not low enough". It is estimated that by 2060, "green hydrogen" will increase from the current 4% to 70%, reaching 90 million tons, and hydrogen energy will account for 15-25% of the total industrial and transportation energy consumption, with a cumulative carbon reduction of 16 billion tons. Carrying out technological innovation on key technologies and equipment for green hydrogen production is of great significance to the country's ecological civilization construction and carbon neutrality.

[0005] The decomposition of water to produce hydrogen through electrocatalysis, photocatalysis and other paths is the core process for converting fluctuating renewable energy into green hydrogen, but the decomposition of water to produce hydrogen requires a large amount of clean water sources. According to statistics, every 3 million tons of hydrogen production requires 5.5 billion liters of water, which is equivalent to the annual water consumption of 1.6 million people, and most of China's renewable energy is concentrated in the western regions with scarce water resources. At the same time, high-carbon industries such as coal, iron and steel smelting, and petrochemicals have a significant demand for green hydrogen, and "green hydrogen" is used to assist the carbon neutrality development of related industries. After a series of complete processes such as chemical oil removal by adding drugs, traditional wastewater is usually discharged into rivers or the sea, and a small number of enterprises recycle the drained water, while most only meet the environmental discharge standards and fail to convert it into industrial energy for utilization.

[0006] Therefore, if industrial wastewater can be directly used to prepare green hydrogen at low cost and low consumption, on the one hand, it can solve the environmental pollution problems caused by wastewater discharge, and on the other hand, it can solve the large demand for fresh water in water decomposition for hydrogen production, which is of great significance for realizing the mutual feedback of "energy-resources-water".

[0007] The difficulty in hydrogen production from wastewater lies in the fact that actual wastewater is very complex and generally contains some organic molecules with strong electron-withdrawing groups and metal ions, etc. These pollutants will consume both oxidative free radicals and reductive electrons simultaneously, causing a large amount of useless work in the entire wastewater treatment process. This will not only reduce the mineralization rate of organic molecules but also inhibit the generation of H2, posing a huge challenge to the application and promotion of hydrogen evolution from actual wastewater. Currently, the main method for hydrogen production from industrial wastewater at home and abroad is the two-step mode of "wastewater purification treatment - hydrogen production from purified water". Through multi-stage pretreatment processes such as solid sedimentation, organic matter separation, and inorganic matter screening, the purity of water is improved, and then hydrogen production from pure water is carried out. It has defects such as complex processes, high costs, and easy secondary environmental pollution. Therefore, how to achieve hydrogen production from wastewater with low cost, high efficiency, and simple processes has become a technical problem urgently to be solved in the environmental protection field. Summary of the Invention

[0008] In view of the defects existing in the existing wastewater hydrogen production technology, the present invention proposes a method and device for synchronous degradation of organic pollutants by wastewater swirl piezoelectric hydrogen production with simple process, low cost, high efficiency, and energy saving.

[0009] To achieve the above object, the present invention provides the following technical solutions:

[0010] In the first aspect of the present invention, there is provided a method for synchronous degradation of organic pollutants by wastewater swirl piezoelectric hydrogen production, including the following steps:

[0011] S1. Uniformly disperse piezoelectric catalyst particles, Fenton / photo-Fenton catalyst particles, inorganic promoter particles, and an oxidant in the organic wastewater to be treated to obtain a solid-liquid mixture system of the organic wastewater to be treated and the catalyst particles, denoted as the first solid-liquid mixture system, and place it in a storage tank;

[0012] S2. Pump the first solid-liquid mixture system from the storage tank tangentially and at high speed into a hydrocyclone reactor through a water pump, so that the first solid-liquid mixture system forms a violent three-dimensional rotating flow field inside the hydrocyclone reactor, and stimulates the piezoelectric effect of the piezoelectric catalyst particles;

[0013] S3. The piezoelectric effect of the piezoelectric catalyst particles acts on the organic wastewater to generate hydrogen inside the hydrocyclone reactor, and at the same time degrade the organic pollutants in the organic wastewater; the hydrogen quickly moves to the central gas core of the hydrocyclone reactor under the drive of the pressure gradient and is discharged from the top overflow port of the hydrocyclone reactor;

[0014] S4. Under the shearing action of the three-dimensional rotating flow field in the hydrocyclone reactor, each catalyst particle revolves around the center of the hydrocyclone reactor, and at the same time, each catalyst particle rotates at a high speed by itself. The high-speed self-rotation of the catalyst particles strengthens the mechanical removal effect on the pollutants attached to their surfaces, thereby realizing the activation of the catalyst. At the same time, the combination of the revolution and self-rotation of the piezoelectric catalyst particles causes the surface of the piezoelectric catalyst particles to be subjected to high-frequency periodic swirling oscillation mechanical stress, further exciting the piezoelectric effect and strengthening the mass transfer process;

[0015] S5. Hydrogen, organic wastewater and a small amount of catalyst particles are discharged from the overflow port of the hydrocyclone reactor and transported to the storage tank through a pipeline. The hydrogen is temporarily stored above the liquid level in the storage tank. The first solid-liquid mixture system after the swirling ends is discharged from the underflow port of the hydrocyclone reactor and returned to the storage tank through a pipeline. The first solid-liquid mixture system returned to the storage tank repeats the above steps S2 - S4 until the entire reaction ends, obtaining a solid-liquid mixture system of organic wastewater and catalyst particles that meets the discharge standards, denoted as the second solid-liquid mixture system;

[0016] S6. After the hydrogen production reaction ends, all the hydrogen in the storage tank is transferred to the hydrogen storage tank. Subsequently, the second solid-liquid mixture system in the storage tank is filtered to obtain catalyst and promoter particles, which are recovered after drying.

[0017] Using advanced oxidation technology to couple with the piezoelectric catalytic system can carry out in-depth treatment of organic wastewater while producing hydrogen, and can realize the "one-step" mode of hydrogen production from wastewater; in the in-depth research of the inventor, it is found that the hydrocyclone reactor can just be used to stimulate the above catalytic system; because the strong three-dimensional rotating flow field in the hydrocyclone reactor can generate very strong swirling oscillation on the solid particles located in this flow field, this strong swirling oscillation acts on the piezoelectric catalytic material particles, can apply periodic directional stress to them, causing them to produce periodic regular deformation, thereby stimulating the above catalytic system, and realizing wastewater treatment while efficiently producing hydrogen; in addition, the catalyst particles carry out self-revolution and coupling movement in the three-dimensional rotating flow field, and the high-speed self-rotation can centrifugally strip the pollutants covering the active sites of the catalyst, thereby realizing the on-line activation of the catalyst, improving the catalytic activity and service life, and further improving the hydrogen production efficiency of wastewater.

[0018] Further, in step S1, the organic wastewater to be treated is simulated pollutant wastewater and / or actual wastewater; the simulated pollutant wastewater is phenolic compound wastewater, antibiotic wastewater, dye wastewater or nitrobenzene compound wastewater; the simulated pollutants are prepared with pure water, tap water, river water, lake water, river water or seawater as solvents; the actual wastewater is industrial wastewater, domestic wastewater, sewage treatment plant effluent or municipal wastewater.

[0019] Further, in step S1, the piezoelectric catalyst is a two-dimensional transition metal chalcogenide with a molecular formula of MX2, where M represents a transition metal element from Group 4 to Group 10, and X is a chalcogen element.

[0020] Further, in step S1, the Fenton / Fenton-like catalyst is a transition metal variable valence ion catalyst.

[0021] Further, in step S1, the Fenton / Fenton-like catalyst is one or more of an Fe source catalyst, a Co source catalyst, a copper source catalyst, a manganese source catalyst, a nickel source catalyst, and a cerium source catalyst.

[0022] Further, in step S1, the inorganic cocatalyst is one or more of metal copper powder, metal iron powder, metal zinc powder, metal cobalt powder, metal tin powder, metal molybdenum powder, divalent iron salts, divalent cobalt salts, and divalent manganese salts.

[0023] Further, in step S1, the oxidant is one or more of hydrogen peroxide, peracetic acid, potassium permanganate, and persulfate.

[0024] Further, in step S1, the persulfate is potassium monopersulfate or potassium persulfate.

[0025] In a second aspect of the present invention, there is provided a device for synchronous degradation of organic pollutants by wastewater swirling piezoelectric hydrogen production for the above-mentioned method of synchronous degradation of organic pollutants by wastewater swirling piezoelectric hydrogen production, including:

[0026] A liquid storage tank for storing the first solid-liquid mixture system; a first liquid outlet is provided at the bottom of the liquid storage tank, a hydrogen detection port and a hydrogen outlet are provided at the top; a first reflux port and a second reflux port are sequentially provided on the upper side wall from top to bottom; a hydrogen output pipeline is provided at the hydrogen outlet.

[0027] A hydrocyclone reactor, a first tangential inlet is provided at a position near the top of its side wall, an overflow port is provided at the top, and an underflow port is provided at the bottom; a first tangential inlet line is provided at the first tangential inlet, an overflow pipeline is provided at the overflow port, and an underflow pipeline is provided at the underflow port; the overflow pipeline is connected to the first reflux port, and the underflow pipeline is connected to the second reflux port.

[0028] A water pump for pumping the first solid-liquid mixture system in the liquid storage tank into the hydrocyclone reactor; the water pump has a pump inlet and a pump outlet, a pump inlet pipeline is provided at the pump inlet, and the pump inlet pipeline is connected to the first liquid outlet; a pump outlet pipeline is provided at the pump outlet, and the pump outlet pipeline is connected to the first tangential inlet line.

[0029] A hydrogen storage tank for storing the produced hydrogen, a hydrogen inlet is provided thereon, and the hydrogen inlet is connected to the hydrogen output pipeline.

[0030] The integrated drying and filtering machine is provided with a second liquid inlet on its side and a second liquid outlet at its bottom; a second liquid inlet pipeline is provided at the second liquid inlet, and the second liquid inlet pipeline is connected to the pump outlet pipeline for filtering the second solid-liquid mixture system in the liquid storage tank after the entire reaction is completed to recover catalyst particles.

[0031] Furthermore, a fan is provided on the hydrogen output pipeline for transferring the hydrogen temporarily stored above the liquid level in the liquid storage tank to the hydrogen storage tank.

[0032] Furthermore, valves are provided on the first tangential inlet line, the second liquid inlet pipeline, and the hydrogen output pipeline.

[0033] Furthermore, a hydrogen concentration detector is provided at the hydrogen detection port.

[0034] The hydrogen concentration detector can detect the hydrogen concentration in the liquid storage tank to ensure that all the hydrogen in the liquid storage tank is transferred to the hydrogen storage tank.

[0035] Compared with the prior art, the present invention has at least the following beneficial effects:

[0036] 1. The method and device for synchronous degradation of organic pollutants by wastewater swirl piezoelectric hydrogen production provided by the present invention achieve efficient hydrogen production under the conditions of low energy consumption, low cost, and simple operation; by exciting the piezoelectric effect in the hydrocyclone reactor, the present invention can be industrially scaled up and has practical applicability; at the same time, the catalyst is easily contaminated in the organic wastewater, resulting in the loss of active sites, while the shear force generated by the turbulent flow field inside the three-dimensional rotating flow field and the self-rotation coupling movement of the particles can desorb the pollutants from the catalyst particles, thereby prolonging the service life of the catalyst and significantly increasing the hydrogen production.

[0037] 2. The method and device for synchronous degradation of organic pollutants by wastewater swirl piezoelectric hydrogen production provided by the present invention degrade the organic pollutants in the organic wastewater while producing hydrogen in the organic wastewater; the catalyst system adopted in the method for synchronous degradation of organic pollutants by wastewater hydrogen production of the present invention couples piezoelectric catalysis through advanced oxidation technology. In the method of the present invention, the piezoelectric effect is excited inside the hydrocyclone reactor. While producing hydrogen, the oxidant is activated in the presence of Fenton / Fenton-like catalysts to generate reactive oxygen species, which oxidize and decompose the organic pollutants to achieve the effect of wastewater treatment.

[0038] 3. The method and device for synchronous degradation of organic pollutants by wastewater swirl piezoelectric hydrogen production provided by the present invention have the advantages of simple operation and small floor area; the first solid-liquid mixture system circulates continuously in the entire process system under the control of the water pump, and the entire reaction process will pass through the hydrocyclone reactor countless times, avoiding multi-stage series connection and realizing the simplicity and high efficiency of the equipment. Description of the Drawings

[0039] Figure 1 It is a schematic process flow diagram of the wastewater cyclone piezoelectric hydrogen production and synchronous degradation of organic pollutants of the present invention.

[0040] Figure 2 It is a bar chart of hydrogen production amount of industrial wastewater cyclone piezoelectric hydrogen production and synchronous degradation of organic pollutants in Example 1 of the present invention.

[0041] Figure 3 It is a schematic diagram of COD degradation amount of industrial wastewater cyclone piezoelectric hydrogen production and synchronous degradation of organic pollutants in Example 1 of the present invention.

[0042] Figure 4 It is a schematic diagram of hydrogen production amount of the method of the present invention for hydrogen production from various wastewaters and synchronous degradation of organic pollutants.

[0043] Figure 5 It is a schematic diagram of degradation results of the method of the present invention for hydrogen production from various wastewaters and synchronous degradation of organic pollutants.

[0044] In the figure: 10 - liquid storage tank; 11 - first liquid outlet; 12 - hydrogen detection port; 121 - hydrogen concentration detector; 13 - hydrogen outlet; 131 - hydrogen output pipeline; 14 - first return port; 15 - second return port;

[0045] 20 - hydrocyclone reactor; 21 - first tangential inlet; 211 - first tangential inlet line; 22 - overflow port; 221 - overflow pipeline; 23 - underflow port; 231 - underflow pipeline;

[0046] 30 - water pump; 31 - pump inlet; 311 - pump inlet pipeline; 32 - pump outlet; 321 - pump outlet pipeline;

[0047] 40 - drying and filtering integrated machine; 41 - second inlet; 411 - second inlet pipeline; 42 - second outlet;

[0048] 50 - hydrogen storage tank; 51 - hydrogen inlet;

[0049] 60 - fan;

[0050] 71 - first valve; 72 - second valve; 73 - third valve. Detailed Embodiments

[0051] The present invention will be further described below in conjunction with specific embodiments. However, it should be understood that these embodiments are only used to illustrate the present invention and do not constitute a limitation to the scope of the present invention.

[0052] Using an advanced oxidation technology to couple a piezoelectric catalysis system, deep treatment of organic wastewater can be carried out while hydrogen production, and a "one-step" mode of hydrogen production from wastewater can be achieved; in the in-depth research of the inventor, it is found that a hydrocyclone reactor can be exactly used to stimulate the above-mentioned catalysis system; a strong three-dimensional rotating flow field will be generated inside the hydrocyclone reactor, which can generate a very strong swirling oscillation on the solid particles located in this flow field. This strong swirling oscillation acts on the piezoelectric catalytic material particles, can apply a periodic directional stress to them, make them produce a periodic regular deformation, thereby stimulating the above-mentioned catalysis system, and realizing wastewater treatment while efficiently producing hydrogen; in addition, the catalyst particles perform a self-rotation coupling movement in the three-dimensional rotating flow field, and the high-speed self-rotation can centrifugally peel off the pollutants covering the active sites of the catalyst, thereby realizing the online activation of the catalyst, improving the catalytic activity and service life, and further improving the hydrogen production efficiency of wastewater. Based on the above research and findings, the present invention has developed a method and device for synchronously degrading organic pollutants and producing hydrogen from wastewater by swirling piezoelectricity, which has the advantages of high efficiency, energy saving, simple process, low cost, small floor area, etc., and effectively solves the problems existing in the prior art.

[0053] Example 1. Method and device for synchronously degrading organic pollutants and producing hydrogen from wastewater by swirling piezoelectricity

[0054] 1.1. Method for synchronously degrading organic pollutants and producing hydrogen from wastewater by swirling piezoelectricity

[0055] This embodiment provides a method for synchronously degrading organic pollutants and producing hydrogen from wastewater by swirling piezoelectricity, which includes the following steps:

[0056] S1. Uniformly disperse piezoelectric catalyst particles, Fenton / Fenton-like catalyst particles, inorganic promoter particles and an oxidant in the organic wastewater to be treated to obtain a solid-liquid mixed system of the organic wastewater to be treated and catalyst particles, denoted as the first solid-liquid mixed system, and place it in a storage tank;

[0057] S2. Pump the first solid-liquid mixed system from the storage tank tangentially into the hydrocyclone reactor through a water pump, so that the first solid-liquid mixed system forms a violent three-dimensional rotating flow field inside the hydrocyclone reactor, and stimulates the piezoelectric effect of the piezoelectric catalyst particles;

[0058] There is an extremely strong directional shear force in this three-dimensional rotating flow field. Such a shear force applies a swirling oscillation mechanical stress (periodic directional mechanical stress) to the piezoelectric catalyst particles, causing the piezoelectric catalyst particles to undergo regular periodic deformation, and then stimulating the piezoelectric effect of the piezoelectric catalyst particles.

[0059] S3. The piezoelectric effect of the piezoelectric catalyst particles acts on the organic wastewater to generate hydrogen inside the hydrocyclone reactor. Meanwhile, the organic pollutants in the organic wastewater are degraded. Due to the existence of a radial pressure gradient inside the hydrocyclone reactor, the central pressure is the lowest, forming a negative pressure zone. Driven by the pressure gradient, hydrogen quickly moves to the central gas core and is discharged from the top overflow port of the hydrocyclone reactor, thus achieving timely removal and separation.

[0060] S4. Under the shearing action of the three-dimensional rotating flow field of the hydrocyclone reactor, each catalyst particle will revolve around the center of the hydrocyclone reactor, and at the same time, each catalyst particle itself will also rotate at a high speed. The high-speed self-rotation of the catalyst particles strengthens the mechanical removal effect on the pollutants attached to their surfaces, thereby exposing the active sites of the catalyst particles, and then realizing the activation of the catalyst. At the same time, the combination of the revolution and self-rotation of the piezoelectric catalyst particles makes the surface of the piezoelectric catalyst particles subject to high-frequency periodic swirling oscillation mechanical stress, further stimulating the piezoelectric effect and strengthening the mass transfer process.

[0061] The catalyst particles are evenly dispersed in the organic wastewater, and their active sites will be invaded by complex pollutants. The pollutants attached to the active sites are likely to make the piezoelectric catalyst lose its activity, thereby reducing the hydrogen production performance. In step S4, after the piezoelectric catalyst particles enter the hydrocyclone reactor, the three-dimensional rotating flow field inside the hydrocyclone reactor will give the catalyst particles a shearing action, making the piezoelectric catalyst particles revolve around the center of the hydrocyclone reactor while rotating at a high speed by themselves. The high-speed self-rotation can centrifugally peel off the pollutants covering the active sites, thereby realizing the on-line activation of the catalyst, improving the catalytic activity and service life, and further improving the hydrogen production efficiency of the wastewater.

[0062] S5. Hydrogen, organic wastewater and a small amount of catalyst particles are discharged from the overflow port of the hydrocyclone reactor and transported to the liquid storage tank through a pipeline. Hydrogen is temporarily stored above the liquid level in the liquid storage tank. The first solid-liquid mixture system after the swirling ends is discharged from the underflow port of the hydrocyclone reactor and transported back to the liquid storage tank through a pipeline. The first solid-liquid mixture system returned to the liquid storage tank repeats the above steps S2 - S4 until the whole reaction ends, obtaining a solid-liquid mixture system of organic wastewater and catalyst particles that meet the discharge standards, denoted as the second solid-liquid mixture system.

[0063] The hydrogen gas flowing out from the overflow port of the hydrocyclone reactor enters the liquid storage tank along the pipeline and is stored above the liquid level; the first solid-liquid mixture system after the swirling ends is discharged from the underflow port of the hydrocyclone reactor and transported back to the liquid storage tank through the pipeline. At the same time, the first solid-liquid mixture system in the liquid storage tank will be pumped back into the hydrocyclone reactor again to carry out piezoelectric catalytic hydrogen production; the whole process is carried out cyclically, and the first solid-liquid mixture system continuously enters the hydrocyclone reactor, thus continuously stimulating the piezoelectric reaction to generate hydrogen; the Fenton / Fenton-like catalyst also continuously generates reactive oxygen species (ROS) during the cyclic process to degrade organic pollutants and achieve the advanced treatment of organic wastewater; the hydrocyclone reactor plays a core strengthening role throughout the process until the reaction ends; finally, an organic wastewater and a solid-liquid mixture system of catalyst particles that meet the discharge standards are obtained, denoted as the second solid-liquid mixture system.

[0064] S6. After the hydrogen production reaction ends, all the hydrogen gas in the liquid storage tank is transferred to the hydrogen storage tank, and then the second solid-liquid mixture system in the liquid storage tank is filtered to obtain catalyst and promoter particles, which are recovered after drying.

[0065] In a preferred embodiment of the present invention, the organic wastewater to be treated in step S1 is simulated pollutant wastewater and / or actual wastewater. The simulated pollutant wastewater is phenolic compound wastewater, antibiotic wastewater, dye wastewater or nitrobenzene compound wastewater; the simulated pollutants are prepared with pure water, tap water, river water, lake water, river water or seawater as the solvent; the actual wastewater is industrial wastewater, domestic wastewater, effluent from a sewage treatment plant or municipal wastewater.

[0066] Furthermore, in step S1, the piezoelectric catalyst is a two-dimensional transition metal chalcogenide with the molecular formula MX2, where M represents a transition metal element from Group 4 to Group 10, and X represents a chalcogen element, specifically, for example, molybdenum disulfide (MoS2), tungsten disulfide (WS2), tungsten selenide (WSe2), etc.; the Fenton / Fenton-like catalyst is a transition metal variable valence ion catalyst, including one or a combination of more of Fe source catalysts, Co source catalysts, copper source catalysts, manganese source catalysts, nickel source catalysts, cerium source catalysts, specifically, for example, FeO, Fe3O4, CoCl2, etc.; the inorganic promoter includes one or a combination of more of metal copper powder, metal iron powder, metal zinc powder, metal cobalt powder, metal tin powder, metal molybdenum powder, divalent iron salts, divalent cobalt salts, divalent manganese salts, specifically, for example, Fe, FeSO4, CoSO4, MnCl2, etc.; the oxidant is one or a combination of more of hydrogen peroxide, peracetic acid, potassium permanganate, persulfates (such as potassium monopersulfate, potassium persulfate, etc.), specifically, for example, potassium monopersulfate, potassium persulfate, KMnO4, etc.

[0067] The hydrogen production process of the present invention is carried out in a hydrocyclone reactor; the first solid-liquid mixture system in the liquid storage tank is pumped out by a water pump and pumped into the hydrocyclone reactor at high speed tangentially, so that a strong three-dimensional rotating flow field is generated in the hydrocyclone reactor; during the process that the piezoelectric catalyst particles follow the three-dimensional rotating flow field and rotate inside the hydrocyclone reactor, they will be subjected to periodic mechanical stress, resulting in lattice distortion, and the positive and negative charge centers of its crystal will shift to form a polarization electric field, realizing the separation of positive and negative charges, and making the H2O and H adsorbed on the surface of the piezoelectric catalyst particles + reduced to H2 by piezoelectric electrons; the piezoelectric holes are captured by the inorganic cocatalyst in the catalytic system (oxygen will not be generated during the hydrogen production process), thus realizing a more efficient charge separation efficiency. At the same time, oxidants such as potassium persulfate are activated to generate reactive oxygen species (ROS) in the presence of Fenton / Fenton-like catalysts, realizing the deep treatment of organic pollutants in organic wastewater.

[0068] 1.2 Device for synchronously degrading organic pollutants by wastewater swirling piezoelectric hydrogen production

[0069] The device for synchronously degrading organic pollutants by wastewater swirling piezoelectric hydrogen production in this embodiment is used for the process method in 1.1 above, as Figure 1 shown, the device includes:

[0070] A liquid storage tank 10 for storing the first solid-liquid mixture system; a first liquid outlet 11 is provided at the bottom of the liquid storage tank 10, a hydrogen detection port 12 and a hydrogen outlet 13 are provided at the top; a first return port 14 and a second return port 15 are successively provided on the upper side wall from top to bottom; a hydrogen output pipeline 131 is provided at the hydrogen outlet 13;

[0071] A hydrocyclone reactor 20, a first tangential inlet 21 is provided at a position near the top of its side wall, an overflow port 22 is provided at the top, and a bottom flow port 23 is provided at the bottom; a first tangential inlet pipeline 211 is provided at the first tangential inlet 21, an overflow pipeline 221 is provided at the overflow port 22, and a bottom flow pipeline 231 is provided at the bottom flow port 23; the overflow pipeline 221 is connected to the first return port 14, and the bottom flow pipeline 231 is connected to the second return port 15;

[0072] A water pump 30 for pumping the first solid-liquid mixture system in the liquid storage tank 10 into the hydrocyclone reactor 20; the water pump 30 has a pump inlet 31 and a pump outlet 32, a pump inlet pipeline 311 is provided at the pump inlet 31, and the pump inlet pipeline 311 is connected to the first liquid outlet 11; a pump outlet pipeline 321 is provided at the pump outlet 32, and the pump outlet pipeline 321 is connected to the first tangential inlet pipeline 211;

[0073] A hydrogen storage tank 50 for storing the produced hydrogen, a hydrogen inlet 51 is provided thereon, and the hydrogen inlet 51 is connected to the hydrogen output pipeline 131;

[0074] The integrated drying and filtering machine 40 is provided with a second liquid inlet 41 on its side and a second liquid outlet 42 at its bottom; a second liquid inlet pipeline 411 is provided at the second liquid inlet 41, and the second liquid inlet pipeline 411 is connected to the pump outlet pipeline 321 for filtering the second solid-liquid mixture system in the liquid storage tank 10 after the whole reaction to recover the catalyst particles;

[0075] The blower 60 is arranged on the hydrogen output pipeline 131 for transferring the hydrogen temporarily stored above the liquid level in the liquid storage tank to the hydrogen storage tank 50;

[0076] The valves are used to control the flow directions of gases and liquids; including a first valve 71, a second valve 72 and a third valve 73. The first valve 71 is arranged on the first tangential inlet line 211, the second valve 72 is arranged on the second liquid inlet pipeline 411, and the third valve 73 is arranged on the hydrogen output pipeline 131.

[0077] When producing hydrogen from wastewater, the first valve 71 is opened, the second and third valves are closed, and the first solid-liquid mixture system in the liquid storage tank 10 is pumped into the hydrocyclone reactor 20 by the water pump 30 to stimulate the piezoelectric effect of the piezoelectric catalyst particles. The piezoelectric electrons on the surface of the piezoelectric catalyst and its surface H2O, H +Hydrogen is produced by the action. In the presence of a Fenton / photo-Fenton catalyst, the oxidant is activated into reactive oxygen species, which act on organic pollutants, degrading the organic pollutants in the organic wastewater. Under the shearing action of the three-dimensional rotating flow field of the hydrocyclone reactor 20, each catalyst particle will revolve around the center of the hydrocyclone reactor 20, and at the same time, each catalyst particle itself will rotate at a high speed. The high-speed rotation of the catalyst particles strengthens the mechanical removal effect on the pollutants attached to their surfaces, thereby exposing the active sites of the catalyst particles, and then realizing the on-line activation of the catalyst. At the same time, the combination of the revolution and rotation of the piezoelectric catalyst particles causes the surface of the piezoelectric catalyst particles to be subjected to high-frequency periodic swirling oscillation mechanical stress, further exciting the piezoelectric effect and strengthening the mass transfer process. Hydrogen, the organic wastewater, and a small amount of catalyst particles are discharged from the overflow port 22 of the hydrocyclone reactor 20 and transported to the liquid storage tank 10 through the overflow pipeline 221. The hydrogen is temporarily stored above the liquid level in the liquid storage tank 10. The first solid-liquid mixture system after the swirling ends is discharged from the underflow port 23 of the hydrocyclone reactor 20 and returned to the liquid storage tank 10 through the underflow pipeline 231. The first solid-liquid mixture system returned to the liquid storage tank 10 re-enters the hydrocyclone reactor 20 under the action of the water pump 30 for catalytic hydrogen production and degradation of organic pollutants. After the whole reaction ends, an organic wastewater that meets the discharge standards and a second solid-liquid mixture system of the catalyst and the promoter particles are obtained. Open the third valve 73 and the fan 60, and transfer the hydrogen stored above the liquid level in the liquid storage tank 10 from the hydrogen outlet 13 through the hydrogen output pipeline 131 and the hydrogen inlet 51 to the hydrogen storage tank 50 for storage. When the hydrogen concentration at the hydrogen detection port 12 is detected to be 0, close the first valve 71 and open the second valve 72. Under the action of the water pump 30, pump the second solid-liquid mixture system in the hydrocyclone reactor 20 into the drying and filtering integrated machine 40. The filtered organic wastewater that meets the discharge standards is discharged from the second liquid outlet 42, and the catalyst and promoter particles are dried and recycled for use.

[0078] Further, a hydrogen concentration detector 121 for detecting the hydrogen concentration above the liquid level in the liquid storage tank 10 is provided at the hydrogen detection port 12 at the top of the liquid storage tank 10 to ensure that all the hydrogen in the liquid storage tank 10 is transferred to the hydrogen storage tank 50.

[0079] The water pump 30 can be used to provide power for the circulation of the first solid-liquid mixture system in the whole reaction process, and at the same time can be used to control the flow rate of the first solid-liquid mixture system, so as to adjust the reaction in real time. After the whole reaction ends, the second solid-liquid mixture system is pumped into the drying and filtering integrated machine 40 by the water pump 30, the catalyst particles and the promoter particles are dried and recycled, and the filtered organic wastewater that meets the discharge standards is discharged.

[0080] In this embodiment, the hydrocyclone reactor can be selected from the hydrocyclones known in the prior art, and different structures of hydrocyclones can be replaced according to the different catalyst particles and water quality used.

[0081] Application Example 1

[0082] The 20 L of industrial wastewater to be treated used in this embodiment was sampled from the factory site, and the initial COD was 1580 mg / L. The specific experimental steps and effect descriptions are as follows:

[0083] S11. 12 g of MoS2 (piezoelectric catalyst particles), 8 g of Fe powder (inorganic co-catalyst particles), 8 g of FeO (Fenton / Fenton-like catalyst particles), and 80 mmol of potassium monopersulfate PMS (oxidant) were uniformly dispersed in 20 L of the organic wastewater to be treated, denoted as the first solid-liquid mixture system, and placed in the storage tank 10.

[0084] S12. The first solid-liquid mixture system was pumped tangentially from the storage tank 10 into the hydrocyclone reactor 20 through the water pump 30, so that the first solid-liquid mixture system formed a violent three-dimensional rotating flow field inside the hydrocyclone reactor 20, stimulating the piezoelectric effect of the piezoelectric catalyst particles MoS2.

[0085] S13. The piezoelectric effect of the piezoelectric catalyst particles MoS2 acts on the organic wastewater to generate hydrogen inside the hydrocyclone reactor 20, and at the same time degrades the organic pollutants in the organic wastewater. Due to the radial pressure gradient inside the hydrocyclone reactor, the central pressure is the smallest, forming a negative pressure zone. The hydrogen quickly moves to the central gas core under the drive of the pressure gradient and is discharged from the top overflow port 22 of the hydrocyclone reactor 20, thus realizing timely removal and separation.

[0086] S14. Under the shearing action of the three-dimensional rotating flow field of the hydrocyclone reactor 20, each catalyst particle will revolve around the center of the hydrocyclone reactor 20, and at the same time each catalyst particle itself will rotate at a high speed. The high-speed rotation of the catalyst particles strengthens the mechanical removal effect on the pollutants attached to its surface, thereby exposing the active sites of the catalyst particles, and then realizing the online activation of the catalyst; at the same time, the combination of the revolution and rotation of the piezoelectric catalyst particles MoS2 makes the surface of the piezoelectric catalyst particles MoS2 receive high-frequency periodic swirling oscillating mechanical stress, further stimulating the piezoelectric effect and strengthening the mass transfer process.

[0087] S15. Hydrogen, organic wastewater and a small amount of catalyst particles are discharged from the overflow port 22 of the hydrocyclone reactor 20 and transported through a pipeline to the liquid storage tank 10. The hydrogen is temporarily stored above the liquid level in the liquid storage tank 10. The first solid-liquid mixture system after the cyclone ends is discharged from the underflow port 23 of the hydrocyclone reactor 20 and transported back to the liquid storage tank 10 through a pipeline. The first solid-liquid mixture system returned to the liquid storage tank 10 repeats the above steps S12 - S14. After 4 hours of reaction, an organic wastewater and a solid-liquid mixture system of catalyst particles that meet the discharge standards are obtained, denoted as the second solid-liquid mixture system.

[0088] S16. All the hydrogen in the liquid storage tank 10 is transferred to the hydrogen storage tank 50. Subsequently, the second solid-liquid mixture system in the liquid storage tank 10 is filtered to obtain catalyst and promoter particles, which are recovered after drying.

[0089] Figure 2 This is a bar chart showing the hydrogen production amount of the hydrocyclone piezoelectric hydrogen production for synchronous degradation of organic pollutants in industrial wastewater in this embodiment. From Figure 2 it can be seen that the hydrogen production amount of the hydrocyclone piezoelectric industrial wastewater for 4 hours in this embodiment is about 70 mmol.

[0090] Figure 3 This is a schematic diagram showing the COD degradation amount of the hydrocyclone piezoelectric hydrogen production for synchronous degradation of organic pollutants in industrial wastewater in this embodiment. From Figure 3 it can be seen that for the piezoelectric degradation of organic pollutants in industrial wastewater for 4 hours in this embodiment, the COD concentration in the industrial wastewater is reduced from 1580 mg / L to 103 mg / L.

[0091] In summary, by using the method of wastewater hydrocyclone piezoelectric hydrogen production for synchronous degradation of organic pollutants of the present invention, the advanced oxidation technology coupled with the piezoelectric catalytic system is well excited through the hydrocyclone reactor, realizing efficient hydrogen production while synchronously degrading organic pollutants in organic wastewater, and achieving the "one-step" mode of wastewater hydrogen production.

[0092] The following application examples verify the universality of the process method of the wastewater hydrocyclone piezoelectric hydrogen production for synchronous degradation of organic pollutants in Example 1; it is proved by experiments that the method of the hydrocyclone piezoelectric wastewater hydrogen production for synchronous degradation of organic pollutants of the present invention can be used for the hydrogen production and synchronous degradation of pollutants in various wastewaters. Among them, (1) is p-nitrochlorobenzene organic wastewater, (2) is p-nitrophenol organic wastewater, (3) is enrofloxacin organic wastewater, (4) is rhodamine B organic wastewater, (5) is phenol organic wastewater, (6) is nitrobenzene organic wastewater, specifically as follows:

[0093] Application Example 2

[0094] Different from Application Example 1, this embodiment is used for (1) p-nitrochlorobenzene organic wastewater; the specific differences are as follows:

[0095] 20 L of wastewater to be treated, with the concentration of p-nitrochlorobenzene in the wastewater being 40 mg / L, the dosage of the piezoelectric catalyst WS2 being 24 g, the dosage of the inorganic co-catalyst component Zn being 16 g, the dosage of the Fenton-like Fenton catalyst CoCl2 being 16 g, and the dosage of the oxidant potassium persulfate (PDS) being 160 mmol;

[0096] React for 4 h, and record its hydrogen production and the degradation rate of p-nitrochlorobenzene in the final organic wastewater, as shown in Figure 4 (Hydrogen production), Figure 5 (Degradation rate of p-nitrochlorobenzene).

[0097] Application Example 3

[0098] Different from Application Example 1, this example is used for (2) p-nitrophenol organic wastewater; the specific difference is:

[0099] 20 L of wastewater to be treated, with the concentration of p-nitrophenol in the wastewater being 40 mg / L, the dosage of the piezoelectric catalyst WS2 being 24 g, the dosage of the inorganic co-catalyst component Zn being 16 g, the dosage of the Fenton-like Fenton catalyst CoCl2 being 16 g, and the dosage of the oxidant potassium persulfate (PDS) being 160 mmol;

[0100] React for 4 h, and record its hydrogen production and the degradation rate of p-nitrophenol in the final organic wastewater, as shown in Figure 4 (Hydrogen production), Figure 5 (Degradation rate of p-nitrophenol).

[0101] Application Example 4

[0102] Different from Application Example 1, this example is used for (3) enrofloxacin organic wastewater; the specific difference is:

[0103] 20 L of wastewater to be treated, with the concentration of enrofloxacin in the wastewater being 40 mg / L, the dosage of the piezoelectric catalyst WS2 being 24 g, the dosage of the inorganic co-catalyst component Zn being 16 g, the dosage of the Fenton-like Fenton catalyst CoCl2 being 16 g, and the dosage of the oxidant potassium persulfate (PDS) being 160 mmol;

[0104] React for 4 h, and record its hydrogen production and the degradation rate of enrofloxacin in the final organic wastewater, as shown in Figure 4 (Hydrogen production), Figure 5 (Degradation rate of enrofloxacin).

[0105] Application Example 5

[0106] Different from Application Example 1, this example is used for (4) rhodamine B organic wastewater; the specific difference is:

[0107] 20 L of wastewater to be treated, the concentration of Rhodamine B in the wastewater is 40 mg / L, the dosage of piezoelectric catalyst WSe2 is 24 g, the dosage of inorganic co-catalyst component FeSO4 is 16 g, the dosage of Fenton-like Fenton catalyst Fe3O4 is 16 g, and the dosage of oxidant potassium persulfate (PDS) is 160 mmol;

[0108] React for 4 h, record its hydrogen production and the degradation rate of Rhodamine B in the final organic wastewater, see Figure 4 (Hydrogen production), Figure 5 (Rhodamine B degradation rate).

[0109] Application Example 6

[0110] Different from Application Example 1, this example is used for (5) phenol organic wastewater; the specific difference is that:

[0111] 20 L of wastewater to be treated, the concentration of phenol in the wastewater is 40 mg / L, the dosage of piezoelectric catalyst WSe2 is 24 g, the dosage of inorganic co-catalyst component FeSO4 is 16 g, the dosage of Fenton-like Fenton catalyst Fe3O4 is 16 g, and the dosage of oxidant potassium persulfate (PDS) is 160 mmol;

[0112] React for 4 h, record its hydrogen production and the degradation rate of phenol in the final organic wastewater, see Figure 4 (Hydrogen production), Figure 5 (Phenol degradation rate).

[0113] Application Example 7

[0114] Different from Application Example 1, this example is used for (6) nitrobenzene organic wastewater; the specific difference is that:

[0115] 20 L of wastewater to be treated, the concentration of nitrobenzene in the wastewater is 40 mg / L, the dosage of piezoelectric catalyst WSe2 is 24 g, the dosage of inorganic co-catalyst component FeSO4 is 16 g, the dosage of Fenton-like Fenton catalyst Fe3O4 is 16 g, and the dosage of oxidant potassium persulfate (PDS) is 160 mmol;

[0116] React for 4 h, record its hydrogen production and the degradation rate of nitrobenzene in the final organic wastewater, see Figure 4 (Hydrogen production), Figure 5 (Nitrobenzene degradation rate).

[0117] Figure 4 It can be seen that under the water quality conditions with different pollutants, good hydrogen production can be achieved;

[0118] Figure 5 It can be seen that the method of the present invention can achieve efficient degradation of different organic pollutants.

[0119] In summary, the method of the present invention activates the advanced oxidation coupled piezoelectric catalysis system through the action of swirl flow, and can achieve the deep treatment of organic pollutants in common organic wastewater while ensuring efficient hydrogen production.

[0120] The above embodiments are only for illustrating the technical concept and characteristics of the present invention, and the purpose is to enable those who are familiar with this technology to understand the content of the present invention and implement it accordingly, and it cannot be used to limit the protection scope of the present invention. Any equivalent transformation or modification made according to the spirit of the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for synchronously degrading organic pollutants and producing hydrogen by wastewater cyclone piezoelectricity, characterized in that It includes the following steps: S1. Uniformly disperse piezoelectric catalyst particles, Fenton / Fenton-like catalyst particles, inorganic promoter particles, and an oxidant in the organic wastewater to be treated to obtain a solid-liquid mixture system of the organic wastewater to be treated and the catalyst particles, denoted as the first solid-liquid mixture system, and place it in a liquid storage tank; S2. Use a water pump to pump the first solid-liquid mixture system from the liquid storage tank tangentially and at high speed into a hydrocyclone reactor, so that the first solid-liquid mixture system forms a violent three-dimensional rotating flow field inside the hydrocyclone reactor, and stimulates the piezoelectric effect of the piezoelectric catalyst particles; S3. The piezoelectric effect of the piezoelectric catalyst particles acts on the organic wastewater, generating hydrogen inside the hydrocyclone reactor, and simultaneously degrading the organic pollutants in the organic wastewater; The hydrogen quickly moves to the central gas core of the hydrocyclone reactor under the drive of the pressure gradient and is discharged from the top overflow port of the hydrocyclone reactor; S4. Under the shearing action of the three-dimensional rotating flow field inside the hydrocyclone reactor, each catalyst particle revolves around the center of the hydrocyclone reactor, and at the same time each catalyst particle rotates at high speed by itself. The high-speed rotation of the catalyst particles strengthens the mechanical removal effect on the pollutants attached to its surface, thereby realizing the activation of the catalyst; At the same time, the combination of the revolution and rotation of the piezoelectric catalyst particles makes the surface of the piezoelectric catalyst particles receive high-frequency periodic swirling oscillation mechanical stress, further stimulating the piezoelectric effect and strengthening the mass transfer process; S5. Hydrogen, organic wastewater, and a small amount of catalyst particles are discharged from the overflow port of the hydrocyclone reactor and transported to the liquid storage tank through a pipeline. The hydrogen is temporarily stored above the liquid level in the liquid storage tank; The first solid-liquid mixture system after the swirling ends is discharged from the underflow port of the hydrocyclone reactor and transported back to the liquid storage tank through a pipeline. The first solid-liquid mixture system returned to the liquid storage tank repeats the above steps S2 to S4 until the entire reaction ends, obtaining a solid-liquid mixture system of organic wastewater and catalyst particles that meets the discharge standards, denoted as the second solid-liquid mixture system; S6. After the hydrogen production reaction ends, transfer all the hydrogen in the liquid storage tank to a hydrogen storage tank, and then filter the second solid-liquid mixture system in the liquid storage tank to obtain catalyst and promoter particles, which are recovered after drying.

2. The method according to claim 1, wherein In step S1, the organic wastewater to be treated is simulated pollutant wastewater and / or actual wastewater; The simulated pollutant wastewater is phenolic compound wastewater, antibiotic wastewater, dye wastewater, or nitrobenzene compound wastewater; The simulated pollutant is prepared with pure water, tap water, river water, lake water, river water, or seawater as the solvent; The actual wastewater is industrial wastewater, domestic wastewater, sewage treatment plant effluent, or municipal wastewater.

3. The method according to claim 1, wherein In step S1, the piezoelectric catalyst is a two-dimensional transition metal chalcogenide, and its molecular formula is MX2, where M represents a transition metal element from Group 4 to Group 10, and X is a chalcogen element.

4. The method according to claim 1, characterized in that, In step S1, the Fenton / Fenton-like catalyst is a transition metal variable valence ion catalyst.

5. The method according to claim 1, wherein In step S1, the Fenton / Fenton-like catalyst is one or more of Fe source catalyst, Co source catalyst, copper source catalyst, manganese source catalyst, nickel source catalyst, and cerium source catalyst.

6. The method according to claim 1, characterized in that, In step S1, the inorganic promoter is one or more of metallic copper powder, metallic iron powder, metallic zinc powder, metallic cobalt powder, metallic tin powder, metallic molybdenum powder, divalent iron salts, divalent cobalt salts, and divalent manganese salts.

7. The method according to claim 1, characterized in that In step S1, the oxidant is one or more of hydrogen peroxide, peracetic acid, potassium permanganate, and persulfates.

8. The method according to claim 7, wherein The persulfate is potassium monopersulfate or potassium persulfate.

9. An apparatus for synchronously degrading organic pollutants and generating hydrogen by wastewater swirling piezoelectricity, characterized in that, For the method according to any one of claims 1 to 8, it includes: A liquid storage tank for storing the first solid-liquid mixture system; the bottom of the liquid storage tank is provided with a first liquid outlet, the top is provided with a hydrogen detection port and a hydrogen outlet; the upper side wall is sequentially provided with a first reflux port and a second reflux port from top to bottom; a hydrogen output pipeline is provided at the hydrogen outlet. A hydrocyclone reactor, the side wall of which is provided with a first tangential inlet near the top, the top is provided with an overflow port, and the bottom is provided with an underflow port; a first tangential inlet line is provided at the first tangential inlet, an overflow pipeline is provided at the overflow port, and an underflow pipeline is provided at the underflow port; the overflow pipeline is connected to the first reflux port, and the underflow pipeline is connected to the second reflux port. A water pump for pumping the first solid-liquid mixture system in the liquid storage tank into the hydrocyclone reactor; the water pump has a pump inlet and a pump outlet, a pump inlet pipeline is provided at the pump inlet, and the pump inlet pipeline is connected to the first liquid outlet; a pump outlet pipeline is provided at the pump outlet, and the pump outlet pipeline is connected to the first tangential inlet line. A hydrogen storage tank for storing the produced hydrogen, which is provided with a hydrogen inlet, and the hydrogen inlet is connected to the hydrogen output pipeline. A drying and filtering integrated machine, the side of which is provided with a second liquid inlet, and the bottom is provided with a second liquid outlet; a second liquid inlet pipeline is provided at the second liquid inlet, and the second liquid inlet pipeline is connected to the pump outlet pipeline, and is used for filtering the second solid-liquid mixture system in the liquid storage tank after the whole reaction to recover the catalyst particles.

10. The device according to claim 9, characterized in that, A fan is provided on the hydrogen output pipeline for transferring the hydrogen temporarily stored above the liquid level in the liquid storage tank to the hydrogen storage tank.

11. The device according to claim 9, characterized in that, Valves are provided on the first tangential inlet line, the second liquid inlet pipeline, and the hydrogen output pipeline.

12. The device according to claim 9, characterized in that, A hydrogen concentration detector is provided at the hydrogen detection port.

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