Electrically-enhanced Fenton-like water treatment method and device system

Abstract

The invention provides an electrically-enhanced Fenton-like water treatment method and device system.The electrically-enhanced Fenton-like water treatment device system comprises an electrically-enhanced Fenton-like catalytic membrane reaction unit, and the electrically-enhanced Fenton-like catalytic membrane reaction unit comprises a sealed insulating shell; the interior of the insulating shell is divided into a cathode part and an anode part by an insulating part, a water inlet is formed in the surface of the insulating shell of the cathode part, and a water outlet is formed in the surface of the insulating shell of the anode part; the cathode part is provided with a cathode, and the anode part is provided with an anode; the cathode is connected with the cathode of the direct-current power supply; the anode is connected with the positive pole of the direct-current power supply; and the material of the cathode comprises a CoFeP / CNTs (CoFeP / Carbon Nanotubes) catalytic membrane. Electrochemistry, a Fenton-like technology and a membrane technology are organically combined, so that the degradation efficiency is effectively improved; the long-term stable operation of the electric strengthening Fenton-like water treatment device system is realized.

Description

Technical Field

[0001] The present invention relates to the field of chemical technology, in particular to the degradation of organic pollutants, and in particular to an electrically enhanced Fenton-type water treatment method and device system. Background Art

[0002] Fenton-like technology has been favored in the treatment of refractory wastewater due to its strong oxidation ability, mild reaction conditions, simple operation and low operating cost. According to the different forms of catalysts, Fenton-like technology is mainly divided into two categories: homogeneous Fenton-like technology and heterogeneous Fenton-like technology. Among them, homogeneous Fenton-like technology uses a variety of transition metal ions (such as Fe 3+ 、Cu 2+ 、Mn 2 + 、Co 2+ Cr 2+ 、Ce 2+ etc.) as homogeneous catalysts to promote the Fenton reaction. However, since the catalyst cannot be effectively recovered, it is not conducive to recycling and reuse. Heterogeneous Fenton-like technologies include dispersed types in which powdered catalysts are added to the solution and loaded types in which the catalysts are loaded on the cathode. Common iron-based dispersed heterogeneous Fenton-like catalysts include zero-valent iron, Fe2O3, Fe3O4, CuO, etc. Heterogeneous Fenton-like technologies are effective technical means for treating antibiotic wastewater, but they have not been widely used due to problems such as low reaction efficiency and poor catalyst regeneration performance.

[0003] CN116813060A discloses a heterogeneous Fenton-like reactor comprising a first water inlet system, a first static mixing catalytic oxidation pipeline, and a first static mixing element; one end of the first static mixing catalytic oxidation pipeline is connected to the first water inlet system, and the other end is provided with a water outlet; the first static mixing element is disposed within the first static mixing catalytic oxidation pipeline; the first static mixing element exhibits Fenton-like catalytic reaction activity; and the ratio of the length to the inner diameter of the first static mixing catalytic oxidation pipeline is 20:1-200:1. This invention effectively couples advanced oxidation technology with direct oxidation transfer technology, ensuring stable effluent quality within a reasonable reagent cost range.

[0004] CN116354546A discloses a deep treatment device for wastewater containing antibiotic-related organic pollutants. The device comprises an advanced oxidation column, a multi-media filter, an ultrafiltration membrane column, and a disinfection module, connected in sequence. The water inlet of the advanced oxidation column is connected to a biological pool and an automatic H2O2 doser. The advanced oxidation column is filled with a heterogeneous Fenton-like Co-Cu catalyst for water oxidation treatment. The multi-media filter uses pressure filtration, the ultrafiltration membrane column uses ultrafiltration membrane filtration, and the disinfection module uses a combination of ultraviolet lamps and disinfectant powder to disinfect the water. This invention achieves deep purification and treatment of wastewater by connecting several reaction columns in series.

[0005] CN110563096A discloses a method and device for strengthening electro-Fenton water treatment, which adds an oxalate reagent package to the electrochemical reduction tank of the electro-Fenton reaction device and sets the cathode as a Ti@TiO2 cathode to achieve Fe 3+ Rapid electroreduction, continuous and rapid replenishment of Fe consumed by the Fenton reaction 2+ , thereby improving the efficiency of pollutant degradation in the electro-reduction Fenton system.

[0006] The Fenton-like water treatment devices disclosed in the prior art have problems such as complex structure, inactivation of active sites, low reaction efficiency, and inability to operate stably for a long time. Therefore, it is of great significance to develop a Fenton-like water treatment device system with a simple structure, high degradation efficiency and long-term stable operation. Summary of the Invention

[0007] In response to the shortcomings of the existing technology, the present invention aims to provide an electrically enhanced Fenton-like water treatment method and device system. By introducing an electrically enhanced Fenton-like catalytic membrane reaction unit, the present invention organically combines electrochemistry, Fenton-like technology, and membrane technology. Pollutants are enriched at the cathode and efficiently degraded in situ, effectively improving degradation efficiency. Through the regeneration of active sites and activation of the catalyst during the degradation process, the electrically enhanced Fenton-like water treatment device system achieves long-term stable operation.

[0008] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides an electrically enhanced Fenton water treatment device system, the electrically enhanced Fenton water treatment device system comprising an electrically enhanced Fenton catalytic membrane reaction unit, the electrically enhanced Fenton catalytic membrane reaction unit comprising a sealed insulating shell, the interior of the insulating shell being divided into a cathode portion and an anode portion by an insulating portion, the insulating shell surface of the cathode portion being provided with a water inlet, and the insulating shell surface of the anode portion being provided with a water outlet;

[0010] The cathode portion is provided with a cathode, and the anode portion is provided with an anode; the cathode is connected to the negative electrode of the DC power supply; and the anode is connected to the positive electrode of the DC power supply;

[0011] The material of the cathode includes CoFeP / CNTs catalytic film.

[0012] The present invention introduces an electrically enhanced Fenton-like catalytic membrane reaction unit, organically combining electrochemistry, Fenton-like technology and membrane technology, effectively improving the degradation efficiency and achieving long-term stable operation of the electrically enhanced Fenton-like water treatment device system.

[0013] In the present invention, Fenton-like technology is coupled with membrane separation technology, and a uniform and stable conductive CoFeP / CNTs catalytic membrane is used as the cathode. When sewage flows through the CoFeP / CNTs catalytic membrane, pollutants are enriched at the cathode, thereby enhancing the utilization efficiency of free radicals and achieving efficient degradation of pollutants; the cathode and anode are respectively connected to the negative and positive poles of a DC power supply, forming a micro-electric field between the cathode and the anode, realizing the valence state cycle of metal ions in CoFeP during the degradation process, and further realizing the regeneration of active sites and activation of the catalyst, ensuring the long-term stable operation of the electrically enhanced Fenton-like water treatment device system.

[0014] Preferably, the anode 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.

[0015] Preferably, the insulating portion includes a mesh-shaped insulating gasket or a foam-shaped insulating gasket.

[0016] Preferably, the electrically enhanced Fenton-type water treatment device system further includes a syringe pump.

[0017] As a preferred technical solution of the present invention, the method for preparing the CoFeP / CNTs catalytic film includes:

[0018] The CoFeP powder and CNTs are dispersed in a solvent and filtered onto the surface of a filter membrane to obtain the CoFeP / CNTs catalytic membrane.

[0019] Preferably, the mass ratio of the CoFeP powder to the CNTs is 1:(0.5-1.5).

[0020] Preferably, the D50 particle size of the CoFeP powder is 50 nm-150 nm.

[0021] Preferably, the diameter of the CNTs is greater than 50 nm.

[0022] Preferably, the dispersion method includes ultrasound.

[0023] Preferably, the filtration is performed no less than 2 times.

[0024] As a preferred technical solution of the present invention, the method for preparing the CoFeP powder includes:

[0025] Under an inert atmosphere, a phosphorus source is placed at the upstream end of an inert gas flow, and a mixture of α-Fe2O3 and Co3O4 is placed at the downstream end of the inert gas flow, and phosphating treatment is performed to obtain a phosphide; the phosphide is immersed in water to obtain the CoFeP powder.

[0026] In the present invention, along the direction of the inert gas flow, the position where the inert gas flows first is defined as the upstream end of the inert gas flow, and the position where the inert gas flows later is defined as the downstream end of the inert gas flow.

[0027] Preferably, the molar ratio of α-Fe2O3 to Co3O4 is 1:(0.5-1).

[0028] Preferably, the phosphorus source comprises sodium hypophosphite.

[0029] Preferably, the temperature of the phosphating treatment is 350°C-500°C.

[0030] Preferably, the phosphating treatment time is 2h-5h.

[0031] Preferably, the inert atmosphere has the same composition as the inert gas flow, including nitrogen and / or an inert gas.

[0032] Preferably, the heating rate of the phosphating treatment is 1.5°C / min-4.5°C / min.

[0033] In a second aspect, the present invention provides an electrically enhanced Fenton-like water treatment method, the method using the electrically enhanced Fenton-like water treatment device system as described in the first aspect, the method comprising:

[0034] Sewage, electrolyte solution and Fenton initiator are added to the injection pump respectively, mixed in the injection pump to obtain a reaction liquid, and the reaction liquid is pumped into the electrically enhanced Fenton catalytic membrane reaction unit from the water inlet on the surface of the insulating shell of the cathode part, flows through the cathode part, the insulating layer and the anode part in sequence, and flows out from the water outlet on the surface of the insulating shell of the anode part, thereby completing the treatment of the sewage.

[0035] Preferably, the electrolyte in the electrolyte solution includes any one of Na2SO4, (NH4)2SO4, K2SO4, NaCl, NH4Cl, KCl, NaNO3, NH4NO3 or KNO3, or a combination of at least two of them.

[0036] Preferably, in the electrolyte solution, the concentration of the electrolyte is 0.03M-0.1M.

[0037] Preferably, the Fenton initiator comprises H2O2.

[0038] Preferably, the concentration of pollutants in the reaction solution is 3 mg / L-10 mg / L.

[0039] Preferably, in the reaction solution, the concentration of the Fenton initiator is 100 mg / L-110 mg / L.

[0040] Preferably, the flow rate of the reaction solution is 0.2 mL / min-1 mL / min.

[0041] Preferably, the hydraulic retention time of the reaction solution when flowing through the electrically enhanced Fenton-type catalytic membrane reaction unit is 0.5s-1.5s.

[0042] Preferably, the current of the DC power supply is 0.5 mA / cm2 based on the area of the CoFeP / CNTs catalyst film. 2 -1.5mA / cm 2 .

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] The present invention organically combines electrochemistry, Fenton-like technology and membrane technology by introducing an electrically enhanced Fenton-like catalytic membrane reaction unit, and uses a uniform and stable conductive CoFeP / CNTs catalytic membrane as the cathode to achieve efficient degradation of pollutants. A micro-electric field is formed between the cathode and the anode, realizing the valence cycle of metal ions in CoFeP during the degradation process, thereby ensuring the long-term stable operation of the electrically enhanced Fenton-like water treatment device system. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a structural schematic diagram of the electrically enhanced Fenton water treatment device system provided in Example 1 of the present invention.

[0046] Figure 2 This is a SEM image of CNTs used in Example 1 of the present invention.

[0047] Figure 3 This is an SEM image of the surface of the CoFeP / CNTs catalyst film prepared in Example 1 of the present invention.

[0048] Figure 4 This is a graph showing the change trend over time of the pollutant content in wastewater after treatment by the electrically enhanced Fenton-like water treatment method provided in Example 1 of the present invention and Comparative Examples 1 to 3.

[0049] Among them, 1-electrically enhanced Fenton-type catalytic membrane reaction unit; 11-mesh insulating gasket; 12-cathode part; 121-CoFeP / CNTs catalytic membrane cathode; 13-anode part; 131-RuO2-plated titanium sheet anode; 14-water inlet; 15-water outlet; 2-injection pump; 3-DC power supply. DETAILED DESCRIPTION

[0050] The technical solution of the present invention is further described below by way of specific embodiments. It should be understood by those skilled in the art that the embodiments are merely to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0051] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in this application are intended to cover non-exclusive inclusions.

[0052] In the description of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly indicate the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0053] In a specific embodiment, the present invention provides an electrically enhanced Fenton water treatment device system, the electrically enhanced Fenton water treatment device system includes an electrically enhanced Fenton catalytic membrane reaction unit, the electrically enhanced Fenton catalytic membrane reaction unit includes a sealed insulating shell, the interior of the insulating shell is divided into a cathode portion and an anode portion by an insulating portion, the insulating shell surface of the cathode portion is provided with a water inlet, and the insulating shell surface of the anode portion is provided with a water outlet;

[0054] The cathode portion is provided with a cathode, and the anode portion is provided with an anode; the cathode is connected to the negative electrode of the DC power supply; and the anode is connected to the positive electrode of the DC power supply;

[0055] The material of the cathode includes CoFeP / CNTs catalytic film.

[0056] The present invention introduces an electrically enhanced Fenton-like catalytic membrane reaction unit, organically combining electrochemistry, Fenton-like technology and membrane technology, effectively improving the degradation efficiency and achieving long-term stable operation of the electrically enhanced Fenton-like water treatment device system.

[0057] In the present invention, a uniform and stable conductive CoFeP / CNTs catalytic membrane is used as the cathode, and the Fenton-like technology is coupled with the membrane separation technology to achieve the enrichment of pollutants at the cathode, enhance the utilization efficiency of free radicals, and thus realize the efficient degradation of pollutants; the cathode and the anode are respectively connected to the negative and positive poles of a DC power supply, forming a micro-electric field between the cathode and the anode, realizing the valence state cycle of metal ions in CoFeP during the degradation process, and further realizing the regeneration of active sites and activation of the catalyst, thereby ensuring the long-term stable operation of the electrically enhanced Fenton-like water treatment device system.

[0058] In some embodiments, the anode 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.

[0059] In some embodiments, the insulating portion includes a mesh insulating gasket or a foam insulating gasket.

[0060] In some embodiments, the electrically enhanced Fenton-type water treatment device system further includes a syringe pump.

[0061] As a preferred technical solution of the present invention, the method for preparing the CoFeP / CNTs catalytic film includes:

[0062] The CoFeP powder and CNTs are dispersed in a solvent and filtered onto the surface of a filter membrane to obtain the CoFeP / CNTs catalytic membrane.

[0063] In the present invention, the type of the solvent is not particularly limited, as long as it can achieve uniform dispersion of CoFeP powder and CNTs, including but not limited to water and / or ethanol.

[0064] In the CoFeP / CNTs catalytic film provided by the present invention, the appropriate mass ratio between CoFeP powder and CNTs ensures that the CoFeP / CNTs catalytic film can be uniformly and stably conductive and has a stable structure. Under the action of a micro-electric field, the CoFeP / CNTs catalytic film has good electron transfer ability.

[0065] In some embodiments, the mass ratio of the CoFeP powder to CNTs is 1:(0.5-1.5), for example, it can be 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1.0, 1:1.1, 1:1.2, 1:1.3, 1:1.4 or 1:1.5, including but not limited to the listed values, and other unlisted values within the numerical range are also applicable.

[0066] In some embodiments, the D50 particle size of the CoFeP powder is 50 nm-150 nm, for example, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 110 nm, 120 nm, 130 nm, 140 nm or 150 nm, including but not limited to the listed values, and other unlisted values within the numerical range are also applicable.

[0067] In the present invention, if the diameter of the CNTs is too small, the structure of the catalyst membrane will be unstable and the distribution between the catalyst and the CNTs will be uneven.

[0068] In some embodiments, the diameter of the CNTs is above 50 nm, for example, 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 90 nm or 100 nm, including but not limited to the listed values, and other values not listed within the numerical range are also applicable.

[0069] In some embodiments, the dispersing method includes ultrasound.

[0070] In some embodiments, the ultrasound time is 0.5h-10h, for example, it can be 0.5h, 1h, 1.5h, 2h, 2.5h, 3h, 4h, 5h, 6h, 7h, 8h, 9h or 10h, including but not limited to the listed values, and other unlisted values within the numerical range are also applicable.

[0071] In some embodiments, the solid-to-liquid ratio of the CoFeP powder to the CNTs to the solvent is 1 mg / mL-10 mg / mL, for example, 1 mg / mL, 2 mg / mL, 3 mg / mL, 4 mg / mL, 5 mg / mL, 6 mg / mL, 7 mg / mL, 8 mg / mL, 9 mg / mL or 10 mg / mL, including but not limited to the listed values, and other values not listed within the numerical range are also applicable.

[0072] In the present invention, the material of the filter membrane is not particularly limited, including but not limited to any one of PVDF, polyethylene, polypropylene or ceramic.

[0073] In the present invention, when the CoFeP powder and CNTs are filtered to the surface of the filter membrane, the method of filtering in batches is beneficial for preparing a CoFeP / CNTs catalytic membrane capable of uniform and stable conductivity.

[0074] In some embodiments, the number of filtrations is no less than 2 times, for example, 2 times, 3 times, 4 times, 5 times, 6 times, or 7 times, including but not limited to the listed values, and other unlisted values within the numerical range are also applicable.

[0075] In some embodiments, the method for preparing the CoFeP powder comprises:

[0076] Under an inert atmosphere, a phosphorus source is placed at the upstream end of an inert gas flow, and a mixture of α-Fe2O3 and Co3O4 is placed at the downstream end of the inert gas flow, and phosphating treatment is performed to obtain a phosphide; the phosphide is immersed in water to obtain the CoFeP powder.

[0077] In the method for preparing CoFeP powder provided by the present invention, impurities are effectively removed by immersing the phosphide after phosphating in water, thereby obtaining a structurally stable CoFeP powder to ensure catalytic efficiency during the degradation process. The immersion time is not particularly limited and can be 10 to 20 hours, for example, 10 hours, 11 hours, 12 hours, 13 hours, 14 hours, 15 hours, 16 hours, 17 hours, 18 hours, 19 hours, or 20 hours.

[0078] In some embodiments, the molar ratio of α-Fe2O3 to Co3O4 is 1:(0.5-1), for example, it can be 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9 or 1:1, including but not limited to the listed values, and other unlisted values within the numerical range are also applicable.

[0079] In some embodiments, the phosphorus source includes sodium hypophosphite. In the present invention, the mass of sodium hypophosphite is much greater than the mass of α-Fe2O3 and Co3O4 to ensure sufficient phosphating to obtain CoFeP. The mass ratio of sodium hypophosphite to α-Fe2O3 and Co3O4 is not particularly limited, but preferably the mass of sodium hypophosphite is at least 5 times the total mass of α-Fe2O3 and Co3O4.

[0080] In some embodiments, the temperature of the phosphating treatment is 350°C-500°C, for example, it can be 350°C, 370°C, 390°C, 410°C, 430°C, 450°C, 470°C, 490°C or 500°C, including but not limited to the listed values, and other unlisted values within the numerical range are also applicable.

[0081] In some embodiments, the phosphating treatment time is 2h-5h, for example, 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.

[0082] In some embodiments, the inert atmosphere has the same composition as the inert gas flow, including nitrogen and / or an inert gas, wherein the inert gas includes helium and / or argon.

[0083] In some embodiments, the heating rate of the phosphating treatment is 1.5°C / min-4.5°C / min, for example, it can be 1.5°C / min, 2°C / min, 2.5°C / min, 3°C / min, 3.5°C / min, 4°C / min or 4.5°C / min, including but not limited to the listed values, and other unlisted values within the numerical range are also applicable.

[0084] In another specific embodiment, the present invention provides an electrically enhanced Fenton-like water treatment method, the method using the electrically enhanced Fenton-like water treatment device system as described in the first aspect, the method comprising:

[0085] Sewage, electrolyte solution and Fenton initiator are added to the injection pump respectively, mixed in the injection pump to obtain a reaction liquid, and the reaction liquid is pumped into the electrically enhanced Fenton catalytic membrane reaction unit from the water inlet on the surface of the insulating shell of the cathode part, flows through the cathode part, the insulating layer and the anode part in sequence, and flows out from the water outlet on the surface of the insulating shell of the anode part, thereby completing the treatment of the sewage.

[0086] In some embodiments, the electrolyte in the electrolyte solution includes any one of Na2SO4, (NH4)2SO4, K2SO4, NaCl, NH4Cl, KCl, NaNO3, NH4NO3 or KNO3, or a combination of at least two of them. Typical but non-limiting combinations include a combination of Na2SO4 and (NH4)2SO4, a combination of K2SO4 and NaCl, a combination of NH4Cl and KCl, a combination of NaNO3 and NH4NO3, or a combination of KNO3 and Na2SO4.

[0087] In some embodiments, in the electrolyte solution, the concentration of the electrolyte is 0.03M-0.1M, for example, it can be 0.03M, 0.04M, 0.05M, 0.06M, 0.07M, 0.08M, 0.09M or 0.1M, including but not limited to the listed values, and other unlisted values within the numerical range are also applicable.

[0088] In some embodiments, the Fenton initiator comprises H2O2.

[0089] In some embodiments, the concentration of the pollutant in the reaction solution is 3 mg / L-10 mg / L, for example, it can be 3 mg / L, 4 mg / L, 5 mg / L, 6 mg / L, 7 mg / L, 8 mg / L, 9 mg / L or 10 mg / L, including but not limited to the listed values, and other unlisted values within the numerical range are also applicable.

[0090] In some embodiments, in the reaction solution, the concentration of the Fenton initiator is 100 mg / L-110 mg / L, for example, it can be 100 mg / L, 101 mg / L, 102 mg / L, 103 mg / L, 104 mg / L, 105 mg / L, 106 mg / L, 107 mg / L, 108 mg / L, 109 mg / L or 110 mg / L, including but not limited to the listed values, and other unlisted values within the numerical range are also applicable.

[0091] In some embodiments, the flow rate of the reaction solution is 0.2 mL / min-1 mL / min, for example, it can be 0.2 mL / min, 0.3 mL / min, 0.4 mL / min, 0.5 mL / min, 0.6 mL / min, 0.7 mL / min, 0.8 mL / min, 0.9 mL / min or 1 mL / min, including but not limited to the listed values, and other unlisted values within the numerical range are also applicable.

[0092] In some embodiments, the hydraulic retention time of the reaction solution when flowing through the electrically enhanced Fenton-type catalytic membrane reaction unit is 0.5s-1.5s, for example, it can be 0.5s, 0.6s, 0.7s, 0.8s, 0.9s, 1s, 1.1s, 1.2s, 1.3s, 1.4s or 1.5s, including but not limited to the listed values, and other unlisted values within the numerical range are also applicable.

[0093] In some embodiments, the current of the DC power supply is 0.5 mA / cm2 based on the area of the CoFeP / CNTs catalyst film. 2 -1.5mA / cm 2 , for example, it can be 0.5 mA / cm 2 , 0.6mA / cm 2 , 0.7mA / cm 2 , 0.8mA / cm 2 , 0.9mA / cm 2 , 1mA / cm 2 , 1.1mA / cm 2 , 1.2mA / cm 2 , 1.3mA / cm 2 , 1.4mA / cm 2 or 1.5mA / cm 2 , including but not limited to the listed values, other unlisted values within the numerical range are also applicable.

[0094] Example 1

[0095] This embodiment provides an electrically enhanced Fenton water treatment device system, such as Figure 1As shown, it includes an electrically enhanced Fenton-type catalytic membrane reaction unit 1, an injection pump 2 and a DC power supply 3.

[0096] The electrically enhanced Fenton-type catalytic membrane reaction unit 1 includes a sealed insulating shell, the interior of which is divided into a cathode portion 12 and an anode portion 13 by a mesh insulating gasket 11. A water inlet 14 is provided on the surface of the insulating shell of the cathode portion 12, and a water outlet 15 is provided on the surface of the insulating shell of the anode portion 13.

[0097] The cathode portion is provided with a CoFeP / CNTs catalytic film cathode 121, and the anode portion is provided with a RuO2-plated titanium sheet anode 131; the cathode 121 is connected to the negative electrode of the DC power supply 3; the anode 131 is connected to the positive electrode of the DC power supply 3.

[0098] The preparation method of the CoFeP / CNTs catalytic film comprises:

[0099] (1) Preparation of CoFeP powder: In a nitrogen atmosphere tube furnace, a nitrogen flow is continuously introduced. A mixture of sodium hypophosphite, 1.9 mmol of α-Fe2O3 and 1.2 mmol of Co3O4 is placed in a porcelain boat in a mass ratio of 5:1. The sodium hypophosphite is placed at the upstream end of the nitrogen flow, and the mixture of α-Fe2O3 and Co3O4 is placed at the downstream end of the nitrogen flow. -1 The phosphide was then ultrasonically dispersed in water, immersed in water for 12 hours, washed with water and ethanol, and dried to obtain CoFeP powder with a D50 particle size of 100 nm.

[0100] (2) Preparation of CoFeP / CNTs catalytic membrane: CoFeP powder prepared in step (1) and CNTs with a diameter of 55 nm were dispersed in a solvent in a mass ratio of 1:1, crushed and ultrasonicated for 30 min, and then vacuum filtered onto the surface of a PVDF filter membrane in 4 steps, and dried to obtain the CoFeP / CNTs catalytic membrane. The SEM image of the CNTs used in this example is shown in FIG. Figure 2 As shown in the SEM image of the surface of the prepared CoFeP / CNTs catalyst film Figure 3 shown.

[0101] This embodiment also provides a method for treating sewage using the electrically enhanced Fenton-type water treatment device system provided in this embodiment, comprising:

[0102] Add wastewater containing SDZ (sulfadiazine), 0.05M Na2SO4 electrolyte solution and H2O2 into syringe pump 2 to obtain a reaction solution with an SDZ concentration of 5 mg / L and an H2O2 concentration of 102 mg / L;

[0103] The cathode 12 and anode 13 of the electrically enhanced Fenton-like catalytic membrane reaction unit 1 are connected to the negative and positive electrodes of the DC power supply 3, respectively. The current of the DC power supply is adjusted to 1 mA / cm based on the area of the prepared CoFeP / CNTs catalytic membrane. 2 ;

[0104] Set the flow rate of the reaction solution to 0.6 mL min -1 The hydraulic retention time is 0.98s. The reaction liquid is pumped into the electrically enhanced Fenton-type catalytic membrane reaction unit from the water inlet 14, flows through the CoFeP / CNTs catalytic membrane cathode 121, the mesh insulating gasket 11 and the RuO2-plated titanium sheet anode 131 in sequence, and is discharged from the water outlet 15 to complete the sewage treatment.

[0105] Example 2

[0106] This embodiment provides an electrically enhanced Fenton-type water treatment device system, which is the same as Example 1 except that the RuO2-plated titanium sheet anode is replaced by a ruthenium dioxide anode, the mesh insulating gasket is replaced by a foam insulating gasket, and the preparation method of the CoFeP / CNTs catalytic membrane is different from that of Example 1.

[0107] The preparation method of the CoFeP / CNTs catalytic film comprises:

[0108] (1) Preparation of CoFeP powder: In a nitrogen atmosphere tube furnace, a nitrogen flow was continuously introduced. A mixture of sodium hypophosphite, 1.9 mmol of α-Fe2O3 and 1 mmol of Co3O4 was placed in a porcelain boat at a mass ratio of 5.5:1. The sodium hypophosphite was placed at the upstream end of the nitrogen flow, and the mixture of α-Fe2O3 and Co3O4 was placed at the downstream end of the nitrogen flow. The mixture was heated at 1.5 °C min -1 The phosphide was then ultrasonically dispersed in water, immersed in water for 10 h, washed with water and ethanol, and dried to obtain CoFeP powder with a D50 particle size of 50 nm.

[0109] (2) Preparation of CoFeP / CNTs catalytic membrane: The CoFeP powder prepared in step (1) and CNTs with a diameter of 50 nm were dispersed in a solvent at a mass ratio of 1:0.5, crushed and ultrasonicated for 30 minutes, and then vacuum filtered twice onto the surface of a polyethylene filter membrane, and dried to obtain the CoFeP / CNTs catalytic membrane.

[0110] This embodiment also provides a method for treating sewage using the electrically enhanced Fenton-type water treatment device system provided in this embodiment, comprising:

[0111] The sewage containing ofloxacin, 0.03M Na2SO4 electrolyte solution and H2O2 were added to the syringe pump to obtain a reaction solution with an ofloxacin concentration of 3 mg / L and an H2O2 concentration of 100 mg / L;

[0112] The cathode and anode of the electrically enhanced Fenton-like catalytic membrane reaction unit were connected to the negative and positive electrodes of a DC power supply, respectively. The current of the DC power supply was adjusted to 0.5 mA / cm based on the area of the prepared CoFeP / CNTs catalytic membrane. 2 ;

[0113] Set the flow rate of the reaction solution to 0.2 mL min -1 , the hydraulic retention time is 0.5s, and the reaction liquid is pumped from the water inlet into the electrically enhanced Fenton-type catalytic membrane reaction unit, flows through the CoFeP / CNTs catalytic membrane cathode, foam insulating gasket and ruthenium dioxide anode in sequence, and is discharged from the water outlet to complete the sewage treatment.

[0114] Example 3

[0115] This embodiment provides an electrically enhanced Fenton-type water treatment device system, which is the same as Example 1 except that the preparation method of the CoFeP / CNTs catalytic membrane is different from that of Example 1.

[0116] The preparation method of the CoFeP / CNTs catalytic film comprises:

[0117] (1) Preparation of CoFeP powder: In a nitrogen atmosphere tube furnace, a nitrogen flow is continuously introduced. Sodium hypophosphite and a mixture of 1 mmol of α-Fe2O3 and 1 mmol of Co3O4 are placed in a porcelain boat at a mass ratio of 5.5:1. Sodium hypophosphite is placed at the upstream end of the nitrogen flow, and the mixture of α-Fe2O3 and Co3O4 is placed at the downstream end of the nitrogen flow. -1 The phosphide was then ultrasonically dispersed in water, immersed in water for 20 h, washed with water and ethanol, and dried to obtain CoFeP powder with a D50 particle size of 150 nm.

[0118] (2) Preparation of CoFeP / CNTs catalytic membrane: The CoFeP powder prepared in step (1) and CNTs with a diameter of 60 nm were dispersed in a solvent at a mass ratio of 1:1.5, crushed and ultrasonicated for 30 minutes, and then vacuum filtered five times onto the surface of a polyethylene filter membrane, and dried to obtain the CoFeP / CNTs catalytic membrane.

[0119] This embodiment also provides a method for treating sewage using the electrically enhanced Fenton-type water treatment device system provided in this embodiment, comprising:

[0120] Sewage containing SDZ (sulfadiazine), 0.1 M Na2SO4 electrolyte solution, and H2O2 were added to the syringe pump to obtain a reaction solution with an SDZ concentration of 10 mg / L and an H2O2 concentration of 110 mg / L;

[0121] The cathode and anode of the electrically enhanced Fenton-like catalytic membrane reaction unit were connected to the negative and positive electrodes of a DC power supply, respectively. The current of the DC power supply was adjusted to 1.5 mA / cm based on the area of the prepared CoFeP / CNTs catalytic membrane. 2 ;

[0122] Set the flow rate of the reaction solution to 1 mL min -1 , the hydraulic retention time is 1.5s, and the reaction liquid is pumped from the water inlet into the electrically enhanced Fenton-type catalytic membrane reaction unit, flows through the CoFeP / CNTs catalytic membrane cathode, the mesh insulating gasket and the RuO2-plated titanium sheet anode in sequence, and is discharged from the water outlet to complete the sewage treatment.

[0123] Example 4

[0124] This embodiment provides an electrically enhanced Fenton-type water treatment device system, which is the same as that of Example 1 except that CNTs with a diameter of 40 nm are selected during the preparation of the CoFeP / CNTs catalytic membrane.

[0125] This embodiment provides an electrically enhanced Fenton-like water treatment method, which is the same as Example 1 except that the electrically enhanced Fenton-like water treatment device system provided in this embodiment is used.

[0126] Example 5

[0127] This embodiment provides an electrically enhanced Fenton-type water treatment device system, which is the same as Example 1 except that during the preparation of CoFeP powder, CoFeP powder with a D50 particle size of 35 nm is prepared.

[0128] This embodiment provides an electrically enhanced Fenton-like water treatment method, which is the same as Example 1 except that the electrically enhanced Fenton-like water treatment device system provided in this embodiment is used.

[0129] Example 6

[0130] This embodiment provides an electrically enhanced Fenton-type water treatment device system, which is the same as Example 1 except that during the preparation of CoFeP powder, CoFeP powder with a D50 particle size of 175 nm is prepared.

[0131] This embodiment provides an electrically enhanced Fenton-like water treatment method, which is the same as Example 1 except that the electrically enhanced Fenton-like water treatment device system provided in this embodiment is used.

[0132] Example 7

[0133] This embodiment provides an electrically enhanced Fenton-type water treatment device system, which is the same as Example 1 except that the obtained phosphide is not immersed in water during the preparation of CoFeP powder.

[0134] This embodiment provides an electrically enhanced Fenton-like water treatment method, which is the same as Example 1 except that the electrically enhanced Fenton-like water treatment device system provided in this embodiment is used.

[0135] Example 8

[0136] This embodiment provides an electrically enhanced Fenton-type water treatment device system, which is the same as Example 1 except that during the preparation of the CoFeP / CNTs catalytic membrane, the dispersion of CoFeP powder and CNTs is vacuum filtered only once to the surface of the PVDF filter membrane.

[0137] This embodiment provides an electrically enhanced Fenton-like water treatment method, which is the same as Example 1 except that the electrically enhanced Fenton-like water treatment device system provided in this embodiment is used.

[0138] Comparative Example 1

[0139] This comparative example provides an electrically enhanced Fenton-type water treatment method, which is the same as Example 1 except that a DC power supply is not used to apply current to the electrically enhanced Fenton-type catalytic membrane reaction unit and a Fenton initiator H2O2 is not added.

[0140] Comparative Example 2

[0141] This comparative example provides an electrically enhanced Fenton-type water treatment method, which is the same as Example 1 except that the Fenton initiator H2O2 is not added.

[0142] Comparative Example 3

[0143] This comparative example provides an electrically enhanced Fenton-type water treatment method, which is the same as Example 1 except that no DC power supply is used to apply current to the electrically enhanced Fenton-type catalytic membrane reaction unit.

[0144] Performance testing:

[0145] The content of pollutants in the sewage treated by the electrically enhanced Fenton-like water treatment method provided in all the above examples and comparative example 1 was tested, and the test method was as follows:

[0146] Sampling was performed every 10 minutes to test the content of pollutants in the treated water and the residual rate of pollutants was calculated: residual rate of pollutants = 100% - concentration after treatment ÷ initial concentration × 100%. The test results are shown in Table 1.

[0147] The changes in the content of pollutants in the wastewater after treatment by the electrically enhanced Fenton-like water treatment method provided in Example 1 and Comparative Examples 1 to 3 over time are shown in FIG. Figure 4 .

[0148] Table 1

[0149]

[0150] According to the test results of Examples 1 to 8 and Comparative Examples 1 to 3, the present invention organically combines electrochemistry, Fenton-like technology and membrane technology by introducing an electrically enhanced Fenton-like catalytic membrane reaction unit, and uses a uniform and stable conductive CoFeP / CNTs catalytic membrane as the cathode, thereby significantly improving the degradation efficiency of pollutants; a micro-electric field is formed between the cathode and the anode, realizing the valence cycle of metal ions in CoFeP during the degradation process, and ensuring the long-term stable operation of the electrically enhanced Fenton-like water treatment device system.

[0151] The applicant declares that the above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention fall within the scope of protection and disclosure of the present invention.

Claims

1. An electrically enhanced Fenton water treatment system, characterized in that: The electrically enhanced Fenton water treatment device system includes an electrically enhanced Fenton catalytic membrane reaction unit, which includes a sealed insulating shell. The interior of the insulating shell is divided into a cathode part and an anode part by an insulating part. The insulating shell surface of the cathode part is provided with a water inlet, and the insulating shell surface of the anode part is provided with a water outlet. The cathode portion is provided with a cathode, and the anode portion is provided with an anode; the cathode is connected to the negative electrode of the DC power supply; and the anode is connected to the positive electrode of the DC power supply; The material of the cathode includes CoFeP / CNTs catalytic film.

2. The electrically enhanced Fenton-type water treatment device system according to claim 1, characterized in that: The anode 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; And / or, the insulating portion includes a mesh insulating gasket or a foam insulating gasket.

3. The electrically enhanced Fenton-type water treatment device system according to claim 1 or 2, characterized in that: The electrically enhanced Fenton water treatment device system also includes a syringe pump.

4. The electrically enhanced Fenton-type water treatment device system according to any one of claims 1 to 3, characterized in that: The preparation method of the CoFeP / CNTs catalytic film comprises: The CoFeP powder and CNTs are dispersed in a solvent and filtered onto the surface of a filter membrane to obtain the CoFeP / CNTs catalytic membrane.

5. The electrically enhanced Fenton-type water treatment device system according to claim 4, characterized in that: The mass ratio of the CoFeP powder to the CNTs is 1:(0.5-1.5); and / or, the CoFeP powder has a D50 particle size of 50 nm to 150 nm; and / or, the diameter of the CNTs is greater than 50 nm; and / or, the dispersing method includes ultrasound; And / or, the number of times of filtration is not less than 2 times.

6. The electrically enhanced Fenton-type water treatment device system according to claim 4, characterized in that: The preparation method of the CoFeP powder comprises: Under an inert atmosphere, a phosphorus source is placed at the upstream end of an inert gas flow, and a mixture of α-Fe2O3 and Co3O4 is placed at the downstream end of the inert gas flow, and phosphating treatment is performed to obtain a phosphide; the phosphide is immersed in water to obtain the CoFeP powder.

7. The electrically enhanced Fenton-type water treatment device system according to claim 6, characterized in that: The molar ratio of α-Fe2O3 to Co3O4 is 1:(0.5-1); and / or, the phosphorus source comprises sodium hypophosphite; And / or, the temperature of the phosphating treatment is 350° C.-500° C.; And / or, the phosphating treatment time is 2h-5h; and / or, the inert atmosphere and the inert gas flow have the same composition as that of nitrogen and / or an inert gas; And / or, the heating rate of the phosphating treatment is 1.5°C / min-4.5°C / min.

8. An electrically enhanced Fenton-type water treatment method, characterized in that: The method uses the electrically enhanced Fenton-type water treatment device system according to any one of claims 1 to 7, and the method comprises: Sewage, electrolyte solution and Fenton initiator are added to the injection pump respectively, mixed in the injection pump to obtain a reaction liquid, and the reaction liquid is pumped into the electrically enhanced Fenton catalytic membrane reaction unit from the water inlet on the surface of the insulating shell of the cathode part, flows through the cathode part, the insulating layer and the anode part in sequence, and flows out from the water outlet on the surface of the insulating shell of the anode part, thereby completing the treatment of the sewage.

9. The electrically enhanced Fenton-like water treatment method according to claim 8, characterized in that: The electrolyte in the electrolyte solution includes any one of Na2SO4, (NH4)2SO4, K2SO4, NaCl, NH4Cl, KCl, NaNO3, NH4NO3 or KNO3, or a combination of at least two thereof; and / or, in the electrolyte solution, the concentration of the electrolyte is 0.03M-0.1M; and / or, the Fenton initiator comprises H2O2; and / or, in the reaction solution, the concentration of the pollutants is 3 mg / L-10 mg / L; And / or, in the reaction solution, the concentration of the Fenton initiator is 100 mg / L-110 mg / L.

10. The electrically enhanced Fenton-like water treatment method according to claim 9, characterized in that: The flow rate of the reaction solution is 0.2mL / min-1mL / min; And / or, the hydraulic retention time of the reaction solution when flowing through the electrically enhanced Fenton-type catalytic membrane reaction unit is 0.5s-1.5s; And / or, based on the area of the CoFeP / CNTs catalyst film, the current of the DC power supply is 0.5 mA / cm 2 -1.5mA / cm 2 .

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