Electro-Fenton filter reaction device and application

Abstract

The invention provides an electro-Fenton filter reaction device and application. The electro-Fenton filter reaction device comprises a constant-current power supply and a filter reaction device, the filter tank reaction device comprises a filter tank reaction shell; the filter reaction shell is divided into an electrode chamber and a reaction chamber by an insulating layer; an electrode is arranged in the electrode chamber; an iron oxide modified activated carbon layer and a conductive material penetrating through the iron oxide modified activated carbon layer are arranged in the reaction chamber. According to the electro-Fenton filter reaction device disclosed by the invention, pollutant adsorption, synchronous in-situ degradation and catalytic site regeneration are combined, so that the pollutant degradation rate is increased, and the electro-Fenton filter reaction device can stably operate for a long time.

Description

Technical Field

[0001] The invention belongs to the technical field of sewage treatment, and specifically relates to the treatment of organic pollutants in sewage, and in particular to an electro-Fenton filter reaction device and application thereof. Background Art

[0002] Fenton chemical oxidation is the use of hydrogen peroxide (H 2 O 2 ) and ferrous ions (Fe 2+ ) reaction to produce hydroxyl free radicals, which is used to oxidize organic pollutants. It is an advanced oxidation treatment technology.

[0003] According to the different forms of iron-based catalysts, the electro-Fenton method is mainly divided into two categories: homogeneous electro-Fenton technology and heterogeneous electro-Fenton technology. Among them, the homogeneous electro-Fenton technology is not conducive to recycling and reuse because the catalyst cannot be effectively recovered. The heterogeneous electro-Fenton technology includes two types: a dispersed type in which the powder catalyst is added to the solution and a loaded type in which the catalyst is loaded on the cathode. Common iron-based dispersed heterogeneous electro-Fenton catalysts include magnetite, zero-valent iron, pyrite, etc. Emerging iron-based loaded heterogeneous electro-Fenton catalysts include graphite felt loaded Fe 3 O 4 , activated carbon fiber loaded with Fe@Fe 2 O 3 In order to achieve the transfer of electrons to the active sites and effectively improve the reaction efficiency. In recent years, some researchers have used the construction of a penetrating electro-Fenton system to enhance the mass transfer of pollutants and the utilization of free radicals through porous electrodes.

[0004] CN114249398A discloses a method for constructing an efficient electro-Fenton cathode material and its application in water treatment. The method takes carbon fiber as the research object, and in the post-treatment process of carbon fiber, the carbon fiber electrode is obtained by sequentially undergoing pre-oxidation, carbonization, graphitization and activation processes, and has a substrate with a high degree of graphitization, so it has excellent conductivity, and its surface has a large number of grooves and rich nitrogen-containing functional groups, so it has a high specific surface area and good two-electron oxygen reduction activity, thereby obtaining an electro-Fenton cathode material with a suitable pore structure, a high specific surface area, good conductivity and electrochemical activity.

[0005] CN117623458A discloses an electric Fenton system cathode, comprising a columnar polymer aerogel embedded in a shell, an electrode sheet with through holes and a columnar electrode active material; the electrode sheet with through holes is in contact with the columnar electrode active material; the pore size of the columnar polymer aerogel is 0.01 to 10 μm; the columnar electrode active material comprises a covalent organic framework material or a modified material containing a covalent organic framework material. The electric Fenton system cathode of the invention can be placed horizontally, and the cathode is prepared using a columnar polymer aerogel with a suitable pore size to improve the degradation effect; the hydrogen peroxide generated by the cathode reduction reaction generates hydroxyl radicals that degrade pollutants in water under the catalysis of the covalent organic framework material, and the electric Fenton system prepared by the cathode does not produce iron mud during use, and does not need to adjust the pH.

[0006] CN116462312A discloses a bio-electric Fenton component, a circulating well device and a system, including an anode chamber, wherein the anode chamber includes an anode and a cathode arranged staggered from the inside and the outside; the electroactive microorganisms loaded on the surface of the anode conductive carrier particles degrade the organic carbon source in the anode liquid to produce protons and electrons, and the cathode uses oxygen as an electron acceptor and combines with the protons transferred from the anode to generate H 2 O 2 , with Fe 3+ Generates Fe as electron acceptor 2+ , a Fenton-like reaction occurs on the cathode surface and degrades the organic pollutants in the cathode liquid, so that the anolyte injected into the chamber inside the electrode and the cathode liquid in the circulation well are purified at the same time.

[0007] The electro-Fenton systems disclosed in the prior art require complex structures to be implemented, and the electrode materials used are usually carbon felt or carbon fiber, which have a low specific surface area and cannot ensure sufficient catalyst loading and pollutant adsorption, resulting in the inability to effectively improve the pollutant degradation rate of the electrode.

[0008] Therefore, it is of great significance to provide an electro-Fenton system with high pollutant degradation rate, regenerative catalytic sites and simple structure, which is suitable for industrial applications. Summary of the invention

[0009] In view of the shortcomings of the prior art, the purpose of the present invention is to provide an electro-Fenton filter reaction device which combines pollutant adsorption, simultaneous in-situ degradation and catalytic site regeneration, has a high pollutant degradation rate and can achieve long-term stable operation.

[0010] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0011] In a first aspect, the present invention provides an electro-Fenton filter reaction device, the electro-Fenton filter reaction device comprising a constant current power supply and a filter reaction device;

[0012] The filter tank reaction device comprises a filter tank reaction shell; the filter tank reaction shell is divided into an electrode chamber and a reaction chamber by an insulating layer;

[0013] An electrode is arranged in the electrode chamber, and the electrode is connected to the positive electrode of the constant current power supply;

[0014] An iron oxide modified activated carbon layer and a conductive material penetrating the iron oxide modified activated carbon layer are arranged in the reaction chamber; the conductive material is connected to the negative electrode of the constant current power supply.

[0015] In the electric-Fenton filter reaction device provided by the present invention, the electrodes and the conductive material are respectively connected to the positive electrode and the negative electrode of the constant current power supply, the conductive material runs through the iron oxide modified activated carbon layer, the current generated by the constant current power supply is conducted to the activated carbon layer, a micro-electric field is formed in the reaction chamber, and the micro-electric field is used to realize the circulation of the valence state of metal ions, thereby realizing the regeneration of active sites and the activation of catalysts, and realizing the long-term stable operation of the electric-Fenton filter reaction device. The present invention realizes the adsorption of pollutants and the synchronous in-situ degradation of pollutants under the action of the micro-electric field through a simple filter structure, greatly improving the degradation efficiency of pollutants.

[0016] Preferably, the electrode comprises any one of a graphite electrode, a titanium ruthenium electrode, a titanium iridium electrode, a ruthenium dioxide electrode, an iridium dioxide electrode or a ruthenium iridium electrode. Typical but non-limiting combinations include: a combination of a titanium ruthenium electrode and a titanium iridium electrode, a combination of a titanium ruthenium electrode and a ruthenium dioxide electrode, a combination of a titanium ruthenium electrode and an iridium dioxide electrode, a combination of a titanium ruthenium electrode and a ruthenium iridium electrode, a combination of a titanium iridium electrode and a ruthenium dioxide electrode, or a combination of an iridium dioxide electrode and a ruthenium iridium electrode.

[0017] Preferably, the iron oxide modified activated carbon layer comprises iron oxide modified activated carbon.

[0018] The iron element loaded on the iron oxide modified activated carbon in the present invention can realize the circulation of metal ion valence under the action of micro-electric field. 2+ Can be with H 2 O 2 The reaction generates hydroxyl radicals to degrade organic pollutants. 3+ Under the action of the micro-electric field, it is reduced to make up for the Fe consumed by the degradation reaction. 2+ .

[0019] Preferably, the iron-containing compound in the iron oxide-modified activated carbon includes Fe 3 O 4 , Fe 2 O 3 or FeO, any one or a combination of at least two thereof, preferably Fe 3 O 4 .

[0020] In the present invention, Fe is selected 3 O 4 , Fe 2 O 3 Or FeO and other iron-containing compounds to modify the activated carbon, and use it in the electro-Fenton filter reaction device, which has higher activity and better stability, and is more conducive to the long-term use of the electro-Fenton filter reaction device.

[0021] Fe 3 O 4 Contains Fe 2+ and Fe 3+ , which increases the Fe content in the system at the beginning of the reaction. 2+ Concentration can more effectively improve the degradation efficiency of organic pollutants.

[0022] In the present invention, the conductive material is connected to the negative electrode of the constant current power supply to transfer electrons to the iron oxide modified activated carbon, and Fe 3+ Reduction to Fe 2+ , in order to realize the circulation of metal ion valence states and ensure the long-term use of the electro-Fenton filter reaction device.

[0023] Preferably, the conductive material includes any one of titanium wire, carbon fiber rod, graphite rod or titanium rod, or a combination of at least two of them.

[0024] Preferably, the titanium wire is a spiral titanium wire.

[0025] In the present invention, the purpose of providing the insulating layer is to achieve electrical insulation between the electrode chamber and the reaction chamber. The electrode chamber and the reaction chamber are allowed to communicate with each other to allow water flow or gas and other substances to pass through.

[0026] Preferably, the insulating layer comprises a mesh insulating gasket or a foam insulating gasket.

[0027] When the electro-Fenton filter reactor provided by the present invention is in use, sewage enters the filter reactor, and organic pollutants in the sewage are adsorbed by the iron oxide modified activated carbon, and are in situ degraded on the surface of the iron oxide modified activated carbon under the action of the micro-electric field and the electro-Fenton reaction to generate CO 2 and water.

[0028] Preferably, the electro-Fenton filter reaction device further comprises a water inlet and a water outlet arranged on the filter reaction shell.

[0029] Preferably, the water inlet is arranged at a position of the filter tank reaction shell corresponding to the bottom of the reaction chamber; the water outlet is arranged at a position of the filter tank reaction shell corresponding to the top of the reaction chamber.

[0030] Preferably, the filter tank reaction shell is also provided with an exhaust device.

[0031] Preferably, the exhaust device is arranged at a position of the filter tank reaction shell corresponding to the top of the reaction chamber.

[0032] Preferably, the exhaust device is a one-way exhaust port.

[0033] In the present invention, a constant current is applied between the electrode chamber and the reaction chamber by a constant current power supply to form a micro-electric field in the reaction chamber, thereby achieving in-situ degradation of organic pollutants on the surface of iron oxide-modified activated carbon and circulation of metal ion valence states.

[0034] Preferably, the current of the constant current power supply is set according to the volume of the reaction chamber. Based on the volume of the reaction chamber, the current applied per unit volume is 0.29mA / mL-1.43mA / mL, for example, 0.29mA / mL, 0.35mA / mL, 0.4mA / mL, 0.45mA / mL, 0.5mA / mL, 0.55mA / mL, 0.6mA / mL, 0.65mA / mL, 0.7mA / mL, 0.8mA / mL, 0.9mA / mL, 10mA / mL, 20mA / mL, 25mA / mL, 26mA / mL, 27mA / mL, 28mA / mL, 29mA / mL, 30mA / mL, 31mA / mL, 32mA / mL, 33mA / mL, 34mA / mL, 36mA / mL, 37mA / mL, 38mA / mL, 39mA / mL, 40mA / mL, 41mA / mL, 42mA / mL, 43mA / mL, 44mA / mL, 45mA / mL, 46mA / mL, 48mA / mL, 49mA / mL, 50mA / mL, 51mA / mL, 52mA / mL, 53mA / mL, 54mA / mL, 55mA / mL, 56mA / mL, 57mA / mL, 58mA / mL, 59mA / mL, 60mA / mL, 61mA / mL, 62mA / mL, 64mA / mL, 65mA / mL, 66mA / mL, 67mA / mL, 68mA / mL, 71m The range of the concentration of the aqueous phase is preferably 0.75mA / mL, 0.8mA / mL, 0.85mA / mL, 0.9mA / mL, 0.95mA / mL, 1mA / mL, 1.05mA / mL, 1.1mA / mL, 1.15mA / mL, 1.2mA / mL, 1.25mA / mL, 1.3mA / mL, 1.35mA / mL or 1.43mA / mL, including but not limited to the listed values, and other values ​​not listed in the numerical range are also applicable. Preferably, it is 0.5-0.9mA / mL.

[0035] Preferably, the method for preparing the iron oxide-modified activated carbon in the iron oxide-modified activated carbon layer comprises the following steps:

[0036] The activated carbon and the iron salt solution are mixed to obtain a mixed solution, a precipitant is added, and the iron oxide modified activated carbon is reacted to obtain the mixed solution.

[0037] The present invention realizes the preparation of iron oxide modified activated carbon by a simple chemical precipitation method, and the prepared iron oxide is uniformly loaded on the surface of the activated carbon, which greatly simplifies the preparation process, reduces the preparation cost, and can be prepared on a large scale.

[0038] Preferably, the particle size of the activated carbon is 10 mesh-60 mesh, for example, it can be 10 mesh, 15 mesh, 20 mesh, 25 mesh, 30 mesh, 35 mesh, 40 mesh, 45 mesh, 50 mesh, 55 mesh or 60 mesh, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0039] In the present invention, activated carbon with a larger specific surface area is selected as a carrier, which, on the one hand, adsorbs organic pollutants in sewage, and, on the other hand, degrades the organic pollutants in situ under the action of electrochemistry.

[0040] Preferably, the specific surface area of ​​the activated carbon is greater than 1000 m 2 / g, for example, it can be 1000m 2 / g, 1050m 2 / g、1100m 2 / g, 1150m 2 / g、1200m 2 / g, 1250m 2 / g、1300m 2 / g, 1350m 2 / g、1400m 2 / g, 1450m 2 / g、1500m 2 / g, 1550m 2 / g or 1600m 2 / g, including but not limited to the listed values, other values ​​not listed in the numerical range are also applicable, preferably greater than 1400m 2 / g.

[0041] Preferably, the iron salt solution comprises any one of ferric chloride, ferrous chloride, ferrous sulfate, ferrous sulfate, ferric nitrate, ferrous nitrate, ferric acetate, and ferrous acetate, or a combination of at least two thereof. Typical but non-limiting combinations include a combination of ferric chloride and ferrous chloride, a combination of ferric sulfate and ferrous sulfate, a combination of ferric nitrate and ferrous nitrate, or a combination of ferric acetate and ferrous acetate.

[0042] Preferably, in the iron salt solution, Fe 3+ The molar concentration is 0mmol / L-40mmol / L, for example, it can be 0mmol / L, 5mmol / L, 10mmol / L, 15mmol / L, 20mmol / L, 25mmol / L, 30mmol / L, 35mmol / L or 40mmol / L, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0043] Fe 2+ The molar concentration is 0-40mmol / L, for example, it can be 0mmol / L, 5mmol / L, 10mmol / L, 15mmol / L, 20mmol / L, 25mmol / L, 30mmol / L, 35mmol / L or 40mmol / L, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0044] Preferably, in the iron salt solution, Fe 3+ with Fe 2+ The molar concentration ratio is 2:1.

[0045] Preferably, in the mixed solution, the concentration of activated carbon is 6 g / L-20 g / L, for example, it can be 6 g / L, 7 g / L, 8 g / L, 9 g / L, 10 g / L, 12 g / L, 14 g / L, 16 g / L, 18 g / L, 20 g / L, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0046] Preferably, calculated according to the mass of the iron element, the mass percentage of iron element in the iron oxide modified activated carbon is 1%-10%, for example, it can be 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5% or 10%, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable, preferably 1.5%-4%.

[0047] Preferably, the precipitating agent comprises any one of sodium hydroxide, potassium hydroxide, sodium bicarbonate or sodium carbonate, or a combination of at least two thereof. Typical but non-limiting combinations include a combination of sodium hydroxide and potassium hydroxide, a combination of potassium hydroxide and sodium bicarbonate, a combination of sodium bicarbonate and sodium carbonate, or a combination of sodium hydroxide and sodium carbonate.

[0048] Preferably, the molar concentration of the precipitant is 2mol / L-10mol / L, for example, it can be 2mol / L, 3mol / L, 4mol / L, 5mol / L, 6mol / L, 7mol / L, 8mol / L, 9mol / L or 10mol / L, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0049] In the present invention, the precipitant is added to the mixed solution at a uniform speed to ensure that the iron element can be evenly loaded on the surface of the activated carbon matrix.

[0050] Preferably, the precipitant is added at a rate of 2 mL / min-30 mL / min, for example, 2 mL / min, 3 mL / min, 4 mL / min, 5 mL / min, 6 mL / min, 7 mL / min, 8 mL / min, 9 mL / min, 10 mL / min, 11 mL / min, 12 mL / min, 13 mL / min, 14 mL / min, 15 mL / min, 20 mL / min, 25 mL / min or 30 mL / min, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable, preferably 5 mL / min-15 mL / min.

[0051] Preferably, in the process of obtaining the iron oxide-modified activated carbon by the reaction, the reaction method includes stirring and standing.

[0052] Preferably, the stirring temperature is 30°C-90°C, for example, it can be 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C or 90°C, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0053] Preferably, the stirring time is 0.5h-5h, for example, it can be 0.5h, 1h, 1.5h, 2h, 2.5h, 3h, 3.5h, 4h, 4.5h or 5h, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0054] Preferably, the standing time is 1 h-6 h, for example, 1 h, 1.5 h, 2 h, 2.5 h, 3 h, 3.5 h, 4 h, 4.5 h, 5 h, 5.5 h or 6 h, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0055] Preferably, after the reaction is completed, the iron oxide-modified activated carbon is further washed and dried.

[0056] Preferably, the washing comprises washing the iron oxide-modified activated carbon to neutrality.

[0057] In the present invention, the process of drying the iron oxide modified activated carbon should avoid the Fe 2+ Oxidized.

[0058] Preferably, the drying comprises drying under an inert atmosphere or freeze drying, preferably freeze drying.

[0059] In a second aspect, the present invention provides an application of the electro-Fenton filter reaction device as described in the first aspect, wherein the electro-Fenton filter reaction device is applied to the degradation of organic pollutants.

[0060] Preferably, when the electro-Fenton filter reaction device is used for the degradation of organic pollutants, the hydraulic retention time is 0.1 min-10 min, for example, it can be 0.1 min, 0.2 min, 0.4 min, 0.6 min, 0.8 min, 1 min, 2 min, 3 min, 4 min, 5 min, 6 min, 7 min, 8 min, 9 min or 10 min, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0061] Preferably, the pH range of the organic pollutant is 2-4, for example, the pH may be 2, 2.2, 2.4, 2.6, 2.8, 3, 3.2, 3.4, 3.6, 3.8 or 4, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0062] Preferably, when the electro-Fenton filter reaction device is used for the degradation of organic pollutants, H 2 O 2 As an initiator.

[0063] Preferably, the H 2 O 2 The relationship between the amount added and the total amount of the organic pollutants satisfies: 2 O 2 / COD=2-20, for example H 2 O 2 / COD can be 2, 4, 6, 8, 10, 12, 14, 16, 18 or 20, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0064] Compared with the prior art, the present invention has the following beneficial effects:

[0065] The present invention provides an electric-Fenton filter reaction device. A micro-electric field is formed in a reaction chamber through the design of an external power supply and a filter structure. The present invention realizes the adsorption of pollutants and the synchronous in-situ degradation of pollutants under the action of the micro-electric field through a simple filter structure, greatly improving the degradation efficiency of pollutants. In addition, the micro-electric field is used to realize the circulation of metal ion valence states, thereby realizing the regeneration of active sites and the activation of catalysts, so that the electric-Fenton filter reaction device can operate stably for a long time. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Figure 1 It is a schematic diagram of the structure of the electro-Fenton filter reaction device provided in Example 1 of the present invention.

[0067] Among them, 1-titanium ruthenium electrode; 2-mesh insulating gasket; 3-Fe 3 O 4 Modified activated carbon layer; 4- spiral titanium wire; 5- constant current power supply; 6- water inlet; 7- water outlet; 8- one-way exhaust port.

[0068] Figure 2 This is a SEM photograph of unloaded activated carbon in Example 1 of the present invention.

[0069] Figure 3 is Fe in Example 1 of the present invention 3 O 4 SEM images of modified activated carbon.

[0070] Figure 4 This is a flow chart of the circulation flow test in Application Example 1 of the present invention.

[0071] Figure 5 It is the degradation curve of sulfadiazine in Application Examples 1 to 7 of the present invention and Comparative Application Examples 1 to 4.

[0072] Figure 6 It is the degradation curve of ofloxacin in Application Examples 1 to 7 of the present invention and Comparative Application Examples 1 to 4.

[0073] Figure 7 This is a flow chart of the unidirectional flow test in Application Example 8 of the present invention.

[0074] Figure 8 It is the penetration curve of sulfadiazine in Application Example 8 of the present invention and Comparative Application Examples 5 to Comparative Application Examples 8. DETAILED DESCRIPTION

[0075] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0076] Example 1

[0077] This embodiment provides a Figure 1 The electro-Fenton filter reaction device shown in the figure comprises a constant current power supply 5 and a filter reaction device, wherein the filter reaction device comprises a titanium ruthenium electrode 1, a mesh insulating gasket 2, a Fe 3 O 4 Modified activated carbon layer 3 and spiral titanium wire 4. The electro-Fenton filter reaction device also includes a water inlet 6, a water outlet 7 and a one-way exhaust port 8. The current applied per unit volume of the reactor is 0.57 mA / mL

[0078] The Fe 3 O 4 Fe in modified activated carbon layer 3 O 4 The preparation method of modified activated carbon comprises the following steps:

[0079] (1) The specific surface area of ​​30 mesh is 1419m 2 / g of activated carbon is dried and mixed with ferric chloride and ferrous chloride iron salt solutions to obtain a mixed solution, wherein Fe 3+ The molar concentration of Fe is 31.2mmol / L. 2+ The molar concentration is 15.6mmol / L, and the concentration of activated carbon in the mixed solution is 7.5g / L.

[0080] (2) The mixed solution obtained in step (1) was heated and maintained at 70° C., 5 mol / L sodium hydroxide solution was uniformly added at a rate of 10 mL / min, stirred for 1 h, allowed to stand for 2 h, filtered, and the resulting precipitate was washed to neutrality, freeze-dried, and the Fe 3 O 4 Modified activated carbon.

[0081] The Fe prepared in this example 3 O 4 The mass ratio of iron in the modified activated carbon is 2%. The SEM photo of the activated carbon used in this example is as follows: Figure 2 As shown, the prepared Fe 3 O 4 The SEM images of modified activated carbon are shown in Figure 3 shown.

[0082] Example 2

[0083] This embodiment provides an electro-Fenton filter reaction device, which includes a constant current power supply and a filter reaction device, and the filter reaction device includes a titanium iridium electrode, a foam insulating gasket, a Fe 3 O 4 Modified activated carbon layer and carbon fiber rod. The electro-Fenton filter reaction device also includes a water inlet, a water outlet and a one-way exhaust port. The current applied per unit volume of the reactor is 0.29 mA / mL.

[0084] The Fe 3 O 4 Fe in modified activated carbon layer 3 O 4 The preparation method of modified activated carbon comprises the following steps:

[0085] (1) The specific surface area of ​​10 mesh is 1628m 2 / g of activated carbon is dried and mixed with ferric chloride and ferrous chloride iron salt solutions to obtain a mixed solution, wherein Fe 3+ The molar concentration of Fe is 27mmol / L. 2+ The molar concentration is 13.5mmol / L, and the concentration of activated carbon in the mixed solution is 6g / L.

[0086] (2) The mixed solution obtained in step (1) was heated and maintained at 30° C., 2 mol / L potassium hydroxide solution was uniformly added at a rate of 5 mL / min, stirred for 0.5 h, allowed to stand for 1 h, filtered, and the resulting precipitate was washed to neutrality, freeze-dried, and the Fe 3 O 4 Modified activated carbon.

[0087] The Fe prepared in this example 3 O 4 The mass ratio of iron element in the modified activated carbon is 1.5%.

[0088] Example 3

[0089] This embodiment provides an electro-Fenton filter reaction device, the electro-Fenton filter reaction device includes a constant current power supply and a filter reaction device, the filter reaction device includes a ruthenium dioxide electrode, a mesh insulating gasket, a Fe 3 O 4 Modified activated carbon layer and graphite rod. The electro-Fenton filter reaction device also includes a water inlet, a water outlet and a one-way exhaust port. The current applied per unit volume of the reactor is 1.43 mA / mL.

[0090] The Fe 3 O 4 Fe in modified activated carbon layer 3 O 4 The preparation method of modified activated carbon comprises the following steps:

[0091] (1) The specific surface area of ​​60 mesh is 1450m 2 / g of activated carbon is dried and mixed with ferric chloride and ferrous chloride iron salt solutions to obtain a mixed solution, wherein Fe 3+ The molar concentration of Fe is 40mmol / L. 2+ The molar concentration is 20mmol / L, and the concentration of activated carbon in the mixed solution is 20g / L.

[0092] (2) The mixed solution obtained in step (1) was heated and maintained at 45° C., 10 mol / L sodium hydroxide solution was uniformly added at a rate of 15 mL / min, stirred for 2 h, allowed to stand for 3 h, filtered, and the resulting precipitate was washed to neutrality, freeze-dried, and the Fe3 O 4 and Fe 2 O 3 Modified activated carbon.

[0093] The Fe prepared in this example 3 O 4 The mass ratio of iron element in the modified activated carbon is 4%.

[0094] Example 4

[0095] This embodiment provides an electro-Fenton filter reaction device, which includes a constant current power supply and a filter reaction device, and the filter reaction device includes an iridium dioxide electrode, a foam insulating gasket, a Fe 3 O 4 and Fe 2 O 3 Modified activated carbon layer and titanium rod. The electro-Fenton filter reaction device also includes a water inlet, a water outlet and a one-way exhaust port. The current applied per unit volume of the reactor is 0.72 mA / mL.

[0096] The Fe 3 O 4 and Fe 2 O 3 Fe in modified activated carbon layer 3 O 4 The preparation method of modified activated carbon comprises the following steps:

[0097] (1) The specific surface area of ​​40 mesh is 1570m 2 / g of activated carbon is dried and mixed with iron salt solutions of ferric sulfate and ferrous sulfate to obtain a mixed solution, wherein Fe 3+ The molar concentration of Fe is 20mmol / L. 2+ The molar concentration is 8mmol / L, and the concentration of activated carbon in the mixed solution is 10g / L.

[0098] (2) The mixed solution obtained in step (1) was heated and maintained at 60° C., 7 mol / L sodium carbonate solution was uniformly added at a rate of 2 mL / min, stirred for 3 h, allowed to stand for 4 h, filtered, and the resulting precipitate was washed to neutrality, and dried in Ar to obtain the Fe 3 O 4 Modified activated carbon.

[0099] The Fe prepared in this example 3 O 4 and Fe 2 O 3 The mass ratio of iron element in the modified activated carbon is 1%.

[0100] Example 5

[0101] This embodiment provides an electro-Fenton filter reaction device, which includes a constant current power supply and a filter reaction device, and the filter reaction device includes a titanium iridium electrode, a mesh insulating gasket, a Fe 2 O 3 Modified activated carbon layer and spiral titanium wire. The electro-Fenton filter reaction device also includes a water inlet, a water outlet and a one-way exhaust port. The current applied per unit volume of the reactor is 0.86 mA / mL.

[0102] The Fe 2 O 3 Fe in modified activated carbon layer 3 O 4 The preparation method of modified activated carbon comprises the following steps:

[0103] (1) The specific surface area of ​​50 mesh is 1480m 2 / g of activated carbon was dried and mixed with ferric acetate solution to obtain a mixed solution, wherein Fe 3+ The molar concentration is 40mmol / L, and the concentration of activated carbon in the mixed solution is 15g / L.

[0104] (2) The mixed solution obtained in step (1) was heated and maintained at 90° C., 8 mol / L sodium bicarbonate solution was uniformly added at a rate of 30 mL / min, stirred for 5 h, allowed to stand for 6 h, filtered, and the resulting precipitate was washed to neutrality, freeze-dried, and the Fe 2 O 3 Modified activated carbon.

[0105] The Fe prepared in this example 2 O 3 The mass ratio of iron element in the modified activated carbon is 10%.

[0106] Example 6

[0107] This embodiment provides an electro-Fenton filter reaction device, which includes a constant current power supply 5 and a filter reaction device, wherein the filter reaction device includes a titanium ruthenium electrode 1, a mesh insulating gasket 2, a Fe 3 O 4 and FeO modified activated carbon layer 3 and spiral titanium wire 4. The electro-Fenton filter reaction device also includes a water inlet 6, a water outlet 7 and a one-way exhaust port 8. The current applied per unit volume of the reactor is 0.57 mA / mL.

[0108] The Fe 3 O 4FeO modified activated carbon layer 3 O 4 The preparation method of modified activated carbon comprises the following steps:

[0109] (1) The specific surface area of ​​30 mesh is 1419m 2 / g of activated carbon is dried and mixed with ferric chloride and ferrous chloride iron salt solutions to obtain a mixed solution, wherein Fe 3+ The molar concentration of Fe is 25mmol / L. 2+ The molar concentration is 25mmol / L, and the concentration of activated carbon in the mixed solution is 7.5g / L.

[0110] (2) The mixed solution obtained in step (1) was heated and maintained at 70° C., 5 mol / L potassium hydroxide solution was uniformly added at a rate of 10 mL / min, stirred for 1 h, allowed to stand for 2 h, filtered, and the resulting precipitate was washed to neutrality, freeze-dried, and the Fe 3 O 4 Modified activated carbon.

[0111] The Fe prepared in this example 3 O 4 In FeO-modified activated carbon, the mass ratio of iron element is 2%.

[0112] Example 7

[0113] This embodiment provides an electro-Fenton filter reaction device. In the process of preparing activated carbon modified by removing iron oxides from the electro-Fenton filter reaction device, the specific surface area of ​​the activated carbon used is 500m 2 / g, the rest are the same as in Example 1.

[0114] Comparative Example 1

[0115] This comparative example provides an electro-Fenton filter reaction device. In addition to 3 O 4 Except that the modified activated carbon layer is replaced with activated carbon loaded with zero-valent iron, the rest is the same as Example 1.

[0116] Comparative Example 2

[0117] This comparative example provides an electro-Fenton filter reaction device, which is the same as Example 1 except that the constant current power supply does not apply current.

[0118] The electro-Fenton filter reaction device of the present invention is used to treat sewage containing organic pollutants (sulfadiazine and ofloxacin).

[0119] First, the wastewater is pretreated. The purpose of the pretreatment is to ensure the comparability of the test results, and it is not a limitation on the application of the electro-Fenton filter reaction device in the present invention. The pretreatment includes adjusting the initial concentration of sulfadiazine in the wastewater to 10 mg / L, the initial concentration of ofloxacin to 10 mg / L, adding an appropriate amount of electrolyte (0.05M Na 2 SO 4 )Adjust the conductivity and adjust the pH of the sewage to 3.

[0120] Application Example 1

[0121] This application example uses the electro-Fenton reaction device provided in Example 1 to perform circulating flow treatment on wastewater containing organic pollutants (sulfadiazine and ofloxacin) to test the degradation rate of antibiotics in the wastewater as a function of reaction time.

[0122] Test conditions: Water containing pollutants enters the reaction chamber from the water inlet at the bottom of the filter tank reaction shell, is discharged from the water outlet at the top of the filter tank reaction shell, passes through the circulation pump, and re-enters the reaction chamber through the water inlet. The circulation flow test process is as follows Figure 4 As shown. 1 mM H 2 O 2 As the initiator of the Fenton reaction, H 2 O 2 The relationship between the amount added and the total amount of the organic pollutants is: 2 O 2 / COD=4. During the degradation reaction, the pretreated wastewater circulates in the reactor through a circulation pump, and the hydraulic retention time is 0.1min.

[0123] Application Example 2

[0124] This application example uses the electro-Fenton reaction device provided in Example 2 to perform circulating flow treatment on wastewater containing organic pollutants (sulfadiazine and ofloxacin) and tests how the degradation rate of antibiotics in the wastewater changes with reaction time.

[0125] The test conditions are the same as those in Application Example 1.

[0126] Application Example 3

[0127] This application example uses the electro-Fenton reaction device provided in Example 3 to perform circulating flow treatment on wastewater containing organic pollutants (sulfadiazine and ofloxacin) to test the degradation rate of antibiotics in the wastewater as a function of reaction time.

[0128] The test conditions are the same as those in Application Example 1.

[0129] Application Example 4

[0130] This application example uses the electro-Fenton reaction device provided in Example 4 to perform circulating flow treatment on wastewater containing organic pollutants (sulfadiazine and ofloxacin) and tests how the degradation rate of antibiotics in the wastewater changes with reaction time.

[0131] The test conditions are the same as those in Application Example 1.

[0132] Application Example 5

[0133] This application example uses the electro-Fenton reaction device provided in Example 5 to perform circulating flow treatment on wastewater containing organic pollutants (sulfadiazine and ofloxacin) and tests how the degradation rate of antibiotics in the wastewater changes with reaction time.

[0134] The test conditions are the same as those in Application Example 1.

[0135] Application Example 6

[0136] This application example uses the electro-Fenton reaction device provided in Example 6 to perform circulating flow treatment on wastewater containing organic pollutants (sulfadiazine and ofloxacin) to test the degradation rate of antibiotics in the wastewater as a function of reaction time.

[0137] The test conditions are the same as those in Application Example 1.

[0138] Application Example 7

[0139] This application example uses the electro-Fenton reaction device provided in Example 7 to perform circulating flow treatment on wastewater containing organic pollutants (sulfadiazine and ofloxacin) to test the degradation rate of antibiotics in the wastewater as a function of reaction time.

[0140] The test conditions are the same as those in Application Example 1.

[0141] Application Example 8

[0142] This application example uses the electro-Fenton reaction device provided in Example 1 to perform unidirectional flow treatment on wastewater containing organic pollutants (sulfadiazine) to test the penetration point of the electro-Fenton filter reaction device.

[0143] Test conditions: Water containing pollutants enters the reaction chamber from the water inlet set at the bottom of the filter tank reaction shell and is discharged from the water outlet set at the top of the filter tank reaction shell. The one-way flow test process is as follows: Figure 7 As shown. 1 mM H 2 O 2 As an initiator of the Fenton reaction, during the degradation reaction, the hydraulic retention time of the pretreated wastewater from the inlet to the outlet in the reactor was 2.2 minutes.

[0144] Comparative application example 1

[0145] This comparative application example uses the electro-Fenton reaction device provided in Comparative Example 1 to perform circulating flow treatment on wastewater containing organic pollutants (sulfadiazine and ofloxacin) to test the degradation rate of antibiotics in the wastewater as a function of reaction time.

[0146] The test conditions are the same as those in Application Example 1.

[0147] Comparative Application Example 2

[0148] This comparative application example uses the electro-Fenton reaction device provided in Comparative Example 2 to perform circulating flow treatment on wastewater containing organic pollutants (sulfadiazine and ofloxacin) to test the degradation rate of antibiotics in the wastewater as a function of reaction time.

[0149] The test conditions are the same as those in Application Example 1.

[0150] Comparative Application Example 3

[0151] This comparative application example uses the electro-Fenton reaction device provided in Example 1 to perform circulating flow treatment on wastewater containing organic pollutants (sulfadiazine and ofloxacin) to test the degradation rate of antibiotics in the wastewater as a function of reaction time.

[0152] The test conditions were as follows except that 1 mM H 2 O 2 Except for being used as the initiator of Fenton reaction, the rest is the same as that of Application Example 1.

[0153] Comparative Application Example 4

[0154] This comparative application example uses the electro-Fenton reaction device provided in Comparative Example 2 to perform circulating flow treatment on wastewater containing organic pollutants (sulfadiazine and ofloxacin) to test the degradation rate of antibiotics in the wastewater as a function of reaction time.

[0155] The test conditions were as follows except that 1 mM H 2 O 2 Except for being used as the initiator of Fenton reaction, the rest is the same as that of Application Example 1.

[0156] Comparative Application Example 5

[0157] This comparative application example uses the electro-Fenton reaction device provided in Comparative Example 1 to perform unidirectional flow treatment on wastewater containing organic pollutants (sulfadiazine) to test the penetration point of the electro-Fenton filter reaction device.

[0158] The test conditions are the same as those in Application Example 8.

[0159] Comparative Application Example 6

[0160] This comparative application example uses the electro-Fenton reaction device provided in Comparative Example 2 to perform unidirectional flow treatment on wastewater containing organic pollutants (sulfadiazine) to test the penetration point of the electro-Fenton filter reaction device.

[0161] The test conditions are the same as those in Application Example 8.

[0162] Comparative Application Example 7

[0163] This comparative application example uses the electro-Fenton reaction device provided in Example 1 to perform unidirectional flow treatment on wastewater containing organic pollutants (sulfadiazine) to test the penetration point of the electro-Fenton filter reaction device.

[0164] The test conditions were as follows except that 1 mM H 2 O 2 Except for being used as an initiator for the Fenton reaction, the rest is the same as in Application Example 8.

[0165] Comparative Application Example 8

[0166] This comparative application example uses the electro-Fenton reaction device provided in Comparative Example 2 to perform unidirectional flow treatment on wastewater containing organic pollutants (sulfadiazine) to test the penetration point of the electro-Fenton filter reaction device.

[0167] The test conditions were as follows except that 1 mM H 2 O 2 Except for being used as an initiator for the Fenton reaction, the rest is the same as in Application Example 8.

[0168] Performance Test:

[0169] The degradation rates of sulfadiazine and ofloxacin in the wastewater treated by Example 1 to Example 7 and Comparative Example 1 to Comparative Example 6 were tested at 1-minute intervals. The test method was to extract 0.5 mL of the reaction solution, quench it with excess methanol, filter it with a 0.22 μm PTFE membrane, and then perform high performance liquid chromatography (HPLC) detection. The test results are shown in Table 1 and Figure 5-Figure 6 shown.

[0170] The penetration point of ofloxacin degradation in the electro-Fenton filter reaction device in Example 8 and Comparative Application Examples 7-12 was tested. The test method was to extract 0.5 mL of the reaction solution, quench it with excess methanol, filter it with a 0.22 μm PTFE membrane, and then perform high performance liquid chromatography (HPLC) detection. The test results are shown in Tables 2 and Figure 8 shown.

[0171] Table 1

[0172] Sulfadiazine degradation rate within 2 minutes / % Ofloxacin degradation rate within 2 minutes / % Application Example 1 100 100 Application Example 2 99.2 99.5 Application Example 3 98.4 99 Application Example 4 87.4 89.4 Application Example 5 80.5 87.5 Application Example 6 82.0 88.0 Application Example 7 73.0 75.0 Comparative application example 1 50.4 49.4 Comparative Application Example 2 72.2 62.2 Comparative Application Example 3 47.3 47.9 Comparative Application Example 4 39.1 35.0

[0173] Table 2

[0174]

[0175]

[0176] According to the data results of Application Examples 1 to 6 of the present invention, when the electric-Fenton filter reaction device provided by the present invention is applied to the degradation of organic pollutants, the activated carbon with a large specific surface area has a strong adsorption capacity for organic pollutants, and the adsorbed pollutants are degraded in situ under the action of the micro-electric field, which greatly improves the degradation efficiency of the pollutants. In addition, the micro-electric field is used to realize the circulation of the valence state of metal ions, thereby realizing the regeneration of active sites and the activation of catalysts, so that the electric-Fenton filter reaction device can operate stably for a long time. In the present invention, the degradation efficiency of organic pollutants can be as high as 100% within 2 minutes.

[0177] According to the data results of Application Example 7, when the specific surface area is only 500m 2 / g of activated carbon acts as a carrier, the degradation efficiency of the prepared electro-Fenton filter reaction device for organic pollutants is significantly reduced.

[0178] According to the data results of Application Example 1 and Comparative Application Examples 1 to Comparative Application Examples 4, in the electro-Fenton filter reaction provided by the present invention, iron oxide-modified activated carbon is used to adsorb and degrade organic pollutants, and the degradation effect is far better than that of zero-valent iron-loaded activated carbon; in Comparative Application Example 2, if the constant current power supply does not apply current, the valence state cycle of metal ions cannot be achieved, and the catalytic active sites cannot be effectively regenerated, so the degradation efficiency decreases, and the long-term stable operation of the electro-Fenton filter reaction system cannot be maintained; in Comparative Application Example 3, no H is added 2 O 2 , which is only the direct electro-oxidation effect of the electric field. It can be seen that the electro-oxidation effect is weak and cannot induce a Fenton-like reaction. This shows that the use of a constant current power supply to apply current to form a micro-electric field in the present invention can only promote the occurrence of a Fenton-like reaction and improve the degradation effect, but cannot replace H 2 O 2 Initiate a Fenton-like reaction; in comparative application example 4, no H 2 O 2 Without applying current, there is only a simple adsorption effect of the iron oxide modified activated carbon, which cannot achieve the degradation of organic pollutants and the degradation effect is significantly deteriorated.

[0179] According to the data results of Application Example 8 and Comparative Application Example 5-Comparative Application Example 8, the effect of using zero-valent iron-loaded activated carbon in Comparative Application Example 5 is not as good as the Fenton degradation effect of iron oxide-modified activated carbon, so it reaches the breakthrough point faster; in Comparative Application Example 6, no current is applied, and the catalytic active sites cannot be effectively regenerated, so the degradation efficiency decreases and reaches the breakthrough point faster; in Comparative Application Example 7, no H is added 2 O 2 , it cannot induce a Fenton-like reaction, it is only a direct electro-oxidation effect of the electric field, and it can be seen that the electro-oxidation effect is weak; compared with Application Example 8, no H is added 2 O 2Without applying current, there is only a simple adsorption effect of the iron oxide-modified activated carbon, which cannot achieve the degradation of sulfadiazine or the regeneration of active sites, so it reaches the penetration point faster.

[0180] The applicant declares that the above is only a specific implementation of the present invention, but the protection scope of the present invention is not limited thereto. The technicians in the technical field should understand that any changes or substitutions that can be easily thought of by the technicians in the technical field within the technical scope disclosed by the present invention are within the protection scope and disclosure scope of the present invention.

Claims

1. An electro-Fenton filter reaction device, characterized in that: The electric Fenton filter reaction device comprises a constant current power supply and a filter reaction device; The filter tank reaction device comprises a filter tank reaction shell; the filter tank reaction shell is divided into an electrode chamber and a reaction chamber by an insulating layer; An electrode is arranged in the electrode chamber, and the electrode is connected to the positive electrode of the constant current power supply; An iron oxide modified activated carbon layer and a conductive material penetrating the iron oxide modified activated carbon layer are arranged in the reaction chamber; the conductive material is connected to the negative electrode of the constant current power supply.

2. The electro-Fenton filter reaction device according to claim 1, characterized in that: The electrode includes any one of a graphite electrode, a titanium ruthenium electrode, a titanium iridium electrode, a ruthenium dioxide electrode, an iridium dioxide electrode or a ruthenium iridium electrode; Preferably, the iron oxide modified activated carbon layer comprises iron oxide modified activated carbon; Preferably, in the iron oxide modified activated carbon, the iron-containing compound includes any one or a combination of at least two of Fe3O4, Fe2O3 or FeO, preferably Fe3O4; Preferably, the conductive material includes any one of titanium wire, carbon fiber rod, graphite rod or titanium rod, or a combination of at least two thereof; Preferably, the titanium wire is a spiral titanium wire.

3. The electro-Fenton filter reaction device according to claim 1 or 2, characterized in that: The insulating layer includes a mesh insulating gasket or a foam insulating gasket.

4. The electro-Fenton filter reaction device according to any one of claims 1 to 3, characterized in that: The electro-Fenton filter reaction device also includes a water inlet and a water outlet arranged on the filter reaction shell; The water inlet is arranged at a position of the filter tank reaction shell corresponding to the bottom of the reaction chamber; the water outlet is arranged at a position of the filter tank reaction shell corresponding to the top of the reaction chamber; Preferably, the filter tank reaction shell is also provided with an exhaust device; Preferably, the exhaust device is arranged at a position of the filter tank reaction shell corresponding to the top of the reaction chamber; Preferably, the exhaust device is a one-way exhaust port.

5. The electro-Fenton filter reaction device according to any one of claims 1 to 4, characterized in that: The current of the constant current power supply is set according to the volume of the reaction chamber. Based on the volume of the reaction chamber, the current applied per unit volume is 0.29 mA / mL-1.43 mA / mL, preferably 0.5-0.9 mA / mL.

6. The electro-Fenton filter reaction device according to any one of claims 1 to 5, characterized in that: The method for preparing the iron oxide modified activated carbon in the iron oxide modified activated carbon layer comprises the following steps: The activated carbon and the iron salt solution are mixed to obtain a mixed solution, a precipitant is added, and the iron oxide modified activated carbon is reacted to obtain the mixed solution.

7. The electro-Fenton filter reaction device according to claim 6, characterized in that: The particle size of the activated carbon is 10 mesh to 60 mesh; Preferably, the specific surface area of ​​the activated carbon is greater than 1000 m 2 / g, preferably greater than 1400m 2 / g; Preferably, the iron salt in the iron salt solution includes any one of ferric chloride, ferrous chloride, ferric sulfate, ferrous sulfate, ferric nitrate, ferrous nitrate, ferrous acetate or ferrous acetate, or a combination of at least two thereof; Preferably, in the iron salt solution, Fe 3+ The molar concentration is 0mmol / L-40mmol / L, Fe 2+ The molar concentration is 0mmol / L-40mmol / L; Preferably, in the iron salt solution, Fe 3+ with Fe 2+ The molar concentration ratio is 2:1; Preferably, in the mixed solution, the concentration of activated carbon is 6 g / L-20 g / L; Preferably, calculated based on the mass of the iron element, the mass percentage of the iron element in the iron oxide modified activated carbon is 1%-10%, preferably 1.5%-4%; Preferably, the precipitant comprises any one of sodium hydroxide, potassium hydroxide, sodium bicarbonate or sodium carbonate, or a combination of at least two thereof; Preferably, the molar concentration of the precipitant is 2 mol / L-10 mol / L; Preferably, the precipitant is added at a rate of 2 mL / min-30 mL / min, preferably 5 mL / min-15 mL / min.

8. The electro-Fenton filter reaction device according to claim 6 or 7, characterized in that: In the process of obtaining the iron oxide modified activated carbon by the reaction, the reaction method includes stirring and standing; Preferably, the stirring temperature is 30°C-90°C; Preferably, the stirring time is 0.5h-5h; Preferably, the standing time is 1h-6h; Preferably, after the reaction is completed, the method further comprises washing and drying the iron oxide-modified activated carbon; Preferably, the washing comprises washing the iron oxide-modified activated carbon to neutrality; Preferably, the drying comprises drying under an inert atmosphere or freeze drying, preferably freeze drying.

9. An application of the electro-Fenton filter reaction device according to any one of claims 1 to 8, characterized in that: The electro-Fenton filter reaction device is used for the degradation of organic pollutants.

10. The use of the electro-Fenton filter reaction device as claimed in claim 9, characterized in that: When the electro-Fenton filter reaction device is used for the degradation of organic pollutants, the hydraulic retention time is 0.1min-10min; Preferably, the pH range of the organic pollutants is 2-4; Preferably, when the electro-Fenton filter reaction device is used for the degradation of organic pollutants, H2O2 needs to be added as an initiator; Preferably, the relationship between the amount of H2O2 added and the total amount of organic pollutants satisfies: H2O2 / COD=2-20.

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