A bipolar membrane mediated electrocatalytic reduction oxidation device, system and method thereof

Abstract

The application relates to a bipolar membrane-mediated electrocatalytic reduction oxidation device, system and method thereof for water treatment, the device comprising a cathode chamber, a first porous Ti4O7 bifunctional electrode, a first polytetrafluoroethylene gasket, a bipolar membrane, a second polytetrafluoroethylene gasket, a second porous Ti4O7 bifunctional electrode and an anode chamber which are sequentially assembled; the cathode chamber and the anode chamber are communicated and are configured as a cascade reaction channel; the first porous Ti4O7 bifunctional electrode and the second porous Ti4O7 bifunctional electrode are respectively connected with a power supply, electrocatalytic reactions occur in the cathode chamber and the anode chamber, and a voltage is provided for the bipolar membrane; the bipolar membrane is used for dissociating water into H + and OH – and migrating to the cathode and the anode respectively; the first polytetrafluoroethylene gasket and the second polytetrafluoroethylene gasket are used for isolating the porous Ti4O7 bifunctional electrode and the bipolar membrane. The application can treat halogenated antibiotics in low-conductivity water without additional addition of electrolyte.

Description

Technical Field

[0001] This invention relates to the field of water treatment technology, specifically to a bipolar membrane-mediated electrocatalytic reduction oxidation device, system, and method for treating halogenated antibiotics in water using bipolar membrane-mediated electrocatalytic reduction oxidation. Background Technology

[0002] Halogenated antibiotics are widely used to treat bacterial infections in humans, animals, and plants. However, only 20%–30% are metabolized by the circulatory system during use, with the remainder excreted into the environment in their original form or as intermediate products. Due to their strong environmental persistence and biotoxicity, conventional physicochemical and biological treatment processes are ineffective in removing them, leading to their widespread detection in surface and groundwater environments. Furthermore, the migration and transformation of these pollutants in the natural environment can induce the spread of antibiotic resistance genes, threatening ecosystem security and human health. Research results indicate that the total concentration of antibiotics in surface and groundwater in typical oases in my country ranges from 17.37 to 84.09 ng∙L⁻¹. -1 and 16.38~277.41ng∙L -1 The study also detected various halogenated antibiotics, such as chloramphenicol and fluoroquinolones. Therefore, developing green and efficient antibiotic water treatment technologies is of great significance for water security and aquatic ecological environment protection.

[0003] Electrocatalytic oxidation technology has advantages such as strong oxidizing power, mild reaction conditions, and high degree of automation. It can achieve efficient removal of recalcitrant organic matter by directly or indirectly generating hydroxyl radicals (•OH) through electrochemistry. However, electrocatalytic oxidation technology has difficulty breaking the carbon-halogen bonds in the molecular structure of antibiotics, and it is easy to generate halogenated intermediates that are more toxic than the parent compound.

[0004] Hydrogen-mediated (•H) electrocatalytic reduction technology outperforms electrocatalytic oxidation technology in dehalogenation efficiency and selectivity. It can selectively remove halogen groups before the ring-opening destructive process of halogenated antibiotics, effectively avoiding the generation of toxic byproducts and preventing the spread of resistance genes, thus providing a reliable process for the safe treatment of halogenated antibiotic wastewater. However, the products after electrocatalytic reduction dehalogenation usually retain the benzene ring molecular structure, making them difficult to effectively mineralize.

[0005] Electrochemical reduction oxidation technology can generate •H at the cathode to initiate a hydrodehalogenation reaction, and then generate •OH at the anode to oxidize and decompose the intermediates after dehalogenation. The synergistic effect of •H / •OH can effectively reduce the reaction energy barrier, which is beneficial to simultaneously improve the dehalogenation and mineralization efficiency. However, when treating halogenated antibiotics in water with low conductivity, electrochemical reduction oxidation technology still has the following technical problems: (1) Reduction and oxidation active species are prone to mutual quenching and self-sacrifice reaction, resulting in low current efficiency; (2) The use of ion exchange membranes leads to alkaline or acidic solutions in the anode and cathode chambers, which increases the overpotential of reduction and oxidation reactions; (3) The conductivity of polluted water bodies (surface water, recycled water, medical wastewater, etc.) is low (< 200 μS / cm), and external electrolytes are required to improve conductivity. However, the addition of external electrolytes limits the competitiveness and application range of electrocatalysis, increases costs, and is prone to secondary pollution.

[0006] Therefore, developing a novel, efficient, and low-consumption electrocatalytic reduction-oxidation system has become an urgent need for the electrochemical deep treatment of halogenated antibiotics in water with low conductivity. Summary of the Invention

[0007] In view of the above, in order to solve at least one of the above-mentioned technical problems, the present invention provides a bipolar membrane-mediated electrocatalytic reduction oxidation device and a method for treating halogenated antibiotics in water, so as to achieve efficient, economical, non-secondary pollution-free, and non-electrolyte-addition-required treatment of halogenated antibiotics in water, thereby solving the problems of difficulty and low efficiency in degrading low concentrations of antibiotics in water.

[0008] Through continuous research, the inventors have discovered that bipolar membrane (BPM)-mediated electrochemical technology, as an emerging ion-exchange membrane electrolysis technology, can solve the aforementioned technical problems faced by electrocatalytic reduction oxidation technology. The bipolar membrane consists of a cation exchange layer (CEL), an anion exchange layer (AEL), and an intermediate interface layer (IL), wherein the intermediate interface layer (IL) is a water dissociation catalyst with a thickness of several nanometers, capable of dissociating water into H+ under reverse bias. + and OH – They migrate towards the anode and cathode respectively; simultaneously, water from both sides of the bipolar membrane passes through the cation exchange layer (CEL) and anion exchange layer (AEL) to enter the intermediate interface layer (IL) to replenish the water consumed. The H+ generated by the in-situ dissociation of water in the bipolar membrane... + / OH –Bipolar membranes can act as electrolyte ions to compensate for the low conductivity in water bodies with low electrolyte concentrations, thus avoiding the need for additional electrolytes. Furthermore, by flexibly adjusting the pH at the electrode interfaces on both sides of the membrane, the cathode and anode can operate under their respective ideal pH conditions, eliminating the need for external acid or alkali regulation. In water treatment and related membrane electrochemistry fields, the most typical engineering application of bipolar membranes is the in-situ generation and separation of acids and alkalis. Traditional electrocatalytic technologies generally rely on the addition of electrolytes such as Na₂SO₄ and NaCl to reduce resistance, or require the wastewater itself to have high conductivity (high-salinity wastewater). Electrochemical water treatment technologies have formed a "high conductivity" path dependency. Furthermore, the H⁺ / OH⁻ generated by BPM dissociation of water is a "locally generated" ion flux, rather than providing a uniform high concentration of migrating ions in the bulk phase as an added electrolyte. Therefore, bipolar membrane technology and electrocatalytic reduction / oxidation technology have long been separated in terms of application objectives, engineering prerequisites, and key control parameters. Bipolar membranes are typically used for acid-base preparation or ion separation, not to replace supporting electrolytes or support electrode reaction currents; while electrocatalytic reduction / oxidation technologies generally rely on high conductivity or added electrolytes. Consequently, due to the inherent thinking of those skilled in the art, existing technologies lack a technical path for in-situ generation of H⁺ / OH⁻ to compensate for conductivity, and no technicians have attempted to introduce bipolar membranes into electrocatalytic reduction-oxidation systems for low-conductivity organic polluted water.

[0009] Furthermore, the inventors have discovered that, in terms of electrode material selection, Magnéli phase titanium suboxide (Ti4O7) exhibits good chemical stability, no heavy metal leaching, and high conductivity (1500 S∙cm). –1 Ti4O7 electrodes, which are comparable to graphite in size and cost-effective, exhibit high hydrogen evolution (-0.8V vs. RHE) and oxygen evolution (2.5V vs. RHE) overpotentials, making them highly efficient dual-function electrodes for reduction and oxidation in water treatment. The microstructure of Ti4O7 can be controlled through a simple calcination method to form a self-supporting microporous electrode, thereby enhancing mass transfer efficiency and further accelerating redox reaction kinetics. Furthermore, the inventors optimized the structure of the bipolar membrane-mediated electrocatalytic reduction-oxidation system, finding that a porous Ti4O7 bifunctional electrode with a pore size range of 10–80 μm, preferably 20 μm, and a thickness range of 0.5–3 mm, preferably 2 mm, can be used in the electrocatalytic reduction-oxidation cascade reaction system of this invention. Within this range, it can reduce interfacial ohmic impedance under low conductivity conditions; enhance the effective migration of H⁺ / OH⁻ generated by BPM to the electrode interface; and improve the residence and mass transfer efficiency of reactants at the electrode / membrane interface.

[0010] Therefore, the inventors have improved the electrocatalytic performance by utilizing the water dissociation characteristics of bipolar membranes and constructing an electrocatalytic reduction oxidation device with a bifunctional Ti4O7 electrode.

[0011] According to a first aspect of the present invention, an embodiment of the present invention provides a bipolar membrane-mediated electrocatalytic reduction oxidation device for water treatment, comprising a cathode chamber, a first porous Ti4O7 bifunctional electrode, a first polytetrafluoroethylene gasket, a bipolar membrane, a second polytetrafluoroethylene gasket, a second porous Ti4O7 bifunctional electrode, and an anode chamber assembled in sequence.

[0012] The cathode chamber and the anode chamber are connected, forming a cascade reaction pathway in which electrocatalytic reduction and electrocatalytic oxidation reactions occur respectively;

[0013] The first porous Ti4O7 bifunctional electrode and the second porous Ti4O7 bifunctional electrode are respectively used to be electrically connected to the power supply, so that electrocatalytic reactions can occur in the cathode chamber and the anode chamber respectively, and provide voltage to the bipolar membrane;

[0014] The bipolar membrane is used to dissociate water into H+. + and OH – And migrate towards the cathode and anode respectively;

[0015] The first polytetrafluoroethylene gasket is used to isolate the first porous Ti4O7 bifunctional electrode and the bipolar membrane; the second polytetrafluoroethylene gasket is used to isolate the second porous Ti4O7 bifunctional electrode and the bipolar membrane.

[0016] In one embodiment, the cathode chamber is used for the electrocatalytic reduction of halogenated antibiotics in the water to be treated under the action of the first porous T4O7 bifunctional electrode to generate a dehalogenated intermediate; the anode chamber is used for the electrocatalytic oxidation of the dehalogenated intermediate under the action of the second porous T4O7 bifunctional electrode.

[0017] In one embodiment, the cathode chamber has a cathode chamber inlet and a cathode chamber outlet, and the anode chamber has an anode chamber inlet and an anode chamber outlet, with the cathode chamber outlet connected to the anode chamber inlet.

[0018] In one embodiment, the cathode chamber has a cathode chamber liquid flow passage for water to be treated to flow therethrough, the cathode chamber liquid flow passage being connected to the cathode chamber inlet and the cathode chamber outlet respectively; the anode chamber has an anode chamber liquid flow passage for water to be treated to flow therethrough, the anode chamber liquid flow passage being connected to the anode chamber inlet and the anode chamber outlet respectively.

[0019] In one embodiment, the cathode chamber is constructed as a semi-shell with a cathode chamber flow path; the anode chamber is constructed as a semi-shell with an anode chamber flow path. Preferably, the liquid flow path in the anode chamber is S-shaped; preferably, the liquid flow path in the cathode chamber is S-shaped.

[0020] In one embodiment, the first porous Ti4O7 bifunctional electrode is electrically connected to the negative terminal of the controllable power supply; the second porous Ti4O7 bifunctional electrode is electrically connected to the positive terminal of the controllable power supply.

[0021] In one embodiment, the pore size of the first porous Ti4O7 bifunctional electrode is 10-80 μm, preferably 20-70 μm, 30-60 μm, or 40-50 μm, and most preferably, the pore size of the first porous Ti4O7 bifunctional electrode is 20 μm; the pore size of the second porous Ti4O7 bifunctional electrode is 10-80 μm, preferably 20-70 μm, 30-60 μm, or 40-50 μm, and most preferably, the pore size of the second porous Ti4O7 bifunctional electrode is 20 μm; and / or,

[0022] In one embodiment, the thickness of the first porous Ti4O7 bifunctional electrode is 0.5~3 mm, preferably 0.6~2.9 mm, 0.7~2.8 mm, 0.8~2.6 mm, 0.9~2.5 mm, 1.0~2.4 mm, 1.1~2.3 mm, 1.2~2.2 mm, 1.3~2.1 mm, 1.4~2.0 mm, 1.5~1.9 mm, or 1.6~1.8 mm. Most preferably, the thickness of the first porous Ti4O7 bifunctional electrode is 2 mm; and / or,

[0023] In one embodiment, the thickness of the second porous Ti4O7 bifunctional electrode is 0.5~3mm, preferably 0.6~2.9mm, 0.7~2.8mm, 0.8~2.6mm, 0.9~2.5mm, 1.0~2.4mm, 1.1~2.3mm, 1.2~2.2mm, 1.3~2.1mm, 1.4~2.0mm, 1.5~1.9mm, 1.6~1.8mm, and most preferably, the thickness of the second porous Ti4O7 bifunctional electrode is 2mm.

[0024] In one embodiment, the first polytetrafluoroethylene (PTFE) gasket has a mounting hole in its center for mounting the first porous Ti4O7 bifunctional electrode, and the second PTFE gasket has a mounting hole in its center for mounting the second porous Ti4O7 bifunctional electrode. And / or,

[0025] In one embodiment, the thickness of the first polytetrafluoroethylene gasket is 0.5~5 mm, preferably 0.6~4.5 mm, 0.7~4.0 mm, 0.8~3.5 mm, 0.9~2.5 mm, or 1.0~2.0 mm, and most preferably, the thickness of the second polytetrafluoroethylene gasket is 2 mm. And / or,

[0026] In one embodiment, the thickness of the first polytetrafluoroethylene gasket is 0.5~5 mm, preferably 0.6~4.5 mm, 0.7~4.0 mm, 0.8~3.5 mm, 0.9~2.5 mm, or 1.0~2.0 mm, and most preferably, the thickness of the second polytetrafluoroethylene gasket is 2 mm. And / or,

[0027] In one embodiment, the thickness of the bipolar film is 50~300μm, preferably 60~290μm, 70~280μm, 80~270μm, 90~260μm, 100~250μm, 110~240μm, 120~230μm, 130~220μm, 140~210μm, 150~200μm, 160~190μm, 170~180μm, and most preferably 130μm.

[0028] In one embodiment, no additional electrolytes are added to the water.

[0029] According to a second aspect of the present invention, an embodiment of the present invention provides a bipolar membrane-mediated electrocatalytic reduction oxidation system, comprising a pump, a storage tank, a controllable power supply, and an electrocatalytic reduction oxidation device as described above;

[0030] The pump is used to deliver water to be treated to the electrocatalytic reduction oxidation device;

[0031] The storage tank is used to store the water to be treated;

[0032] The controllable power supply is used to power the electrocatalytic reduction oxidation device, and the power supply voltage is adjustable.

[0033] According to a third aspect of the present invention, embodiments of the present invention provide a method for treating halogenated antibiotics in water by bipolar membrane-mediated electrocatalytic reduction oxidation. The method utilizes the aforementioned electrocatalytic reduction oxidation device, which comprises a cathode chamber, a first porous Ti4O7 bifunctional electrode, a first polytetrafluoroethylene (PTFE) gasket, a bipolar membrane, a second PTFE gasket, a second porous Ti4O7 bifunctional electrode, and an anode chamber assembled sequentially. The cathode chamber and the anode chamber are connected, configured as a cascade reaction pathway in which electrocatalytic reduction and electrocatalytic oxidation reactions occur respectively. The method includes the following steps:

[0034] (S1) The halogenated antibiotic in the water to be treated is electrocatalytically reduced and nucleophilically dehalogenated in the cathode chamber to generate a dehalogenated intermediate. The bipolar membrane catalyzes the dissociation of water to produce H2O. + ;

[0035] (S2) The water to be treated, containing the dehalogenated intermediate, flows from the cathode chamber into the anode chamber;

[0036] (S3) The dehalogenated intermediate in the water to be treated is electrocatalytically oxidized and decomposed in the anode chamber, and the bipolar membrane catalyzes the dissociation of water to produce OH-. – ;

[0037] (S4) The treated water is discharged from the outlet of the anode chamber.

[0038] In one embodiment, the current density through the first porous Ti4O7 bifunctional electrode ranges from 1 to 100 A / m. 2 Preferably 1-100A / m 2 5-90A / m 2 10-80A / m 2 15-70A / m 2 20-60A / m 2 30-50A / m 2 Most preferably, the current density through the first porous Ti4O7 bifunctional electrode is 40 A / m. 2 ; and / or

[0039] In one embodiment, the current density of the second porous Ti4O7 bifunctional electrode ranges from 1 to 100 A / m. 2 Preferably 1-100A / m 2 5-90A / m 2 10-80A / m 2 15-70A / m 2 20-60A / m 2 30-50A / m 2 Most preferably, the current density through the second porous Ti4O7 bifunctional electrode is 40 A / m. 2 .

[0040] The beneficial effects of the embodiments of the present invention are:

[0041] 1. This invention breaks through the bottleneck of requiring the addition of electrolytes and producing toxic byproducts in the electrocatalytic treatment of halogenated antibiotics in water with low conductivity (0.1~200 μS / cm). It eliminates the need for additional electrolytes and broadens the applicability of electrocatalytic technology.

[0042] 2. Nucleophilic-electrophilic cascade reactions are beneficial for the deep removal of halogenated antibiotics from water, solving the problem of easy quenching of reductively oxidized active species.

[0043] 3. The porous bifunctional Ti4O7 electrode has high hydrogen and oxygen evolution overpotentials, which can reduce side reactions and improve the degradation efficiency of halogenated antibiotics in water. Furthermore, under optimal operation, the Ti4O7 anode and cathode can be switched by reversing the electrodes, thereby preventing the anode from passivating into TiO2 and causing a decrease in catalytic activity.

[0044] 4. The electrocatalytic reduction oxidation system of the present invention is small in size and easy to disassemble and maintain. Attached Figure Description

[0045] Figure 1 This is a schematic diagram illustrating the composition of a bipolar membrane-mediated electrocatalytic reduction-oxidation system and the process for treating halogenated antibiotics in water, according to an embodiment of the present invention.

[0046] Figure 2 This is a schematic diagram of the structure of the cathode chamber of a bipolar membrane-mediated electrocatalytic reduction oxidation device according to an embodiment of the present invention. The cathode chamber has an S-shaped flow path; the anode chamber and the cathode chamber can have the same structure.

[0047] Figure 3 This is a schematic diagram illustrating the principle of a bipolar membrane-mediated electrocatalytic reduction oxidation device for treating halogenated antibiotics in water.

[0048] Figure 4 This is a schematic diagram of the structure of a polytetrafluoroethylene gasket in a bipolar membrane-mediated electrocatalytic reduction oxidation device according to an embodiment of the present invention. An electrode is placed in the center of the gasket. It serves to fix the electrode and prevent leakage of the device.

[0049] Figure 5 This is a porous Ti4O7 bifunctional electrode of a bipolar membrane-mediated electrocatalytic reduction oxidation device according to an embodiment of the present invention.

[0050] Figure 6 These are experimental data from an embodiment of the present invention on the treatment of sodium diclofenac (DCF) in water with low conductivity using a bipolar membrane-mediated electrocatalytic reduction-oxidation system. The data were obtained at a current density of 40 A / m. 2 Under these conditions, the concentration of sodium diclofenac (DCF) in ultra-low conductivity water (<0.1 μS / cm) changes over time. It is evident that the system of this invention can still achieve 40 A / m in ultra-low conductivity water. 2 The reaction current.

[0051] Figure 7 These are experimental data from an embodiment of the present invention on the treatment of sulfamethoxazole (SMX) in water with ultra-low conductivity (<0.1 μS / cm) using a bipolar membrane-mediated electrocatalytic reduction-oxidation system. The data were obtained at a current density of 40 A / m. 2 The change of sulfamethoxazole (SMX) concentration in water over time under certain conditions.

[0052] Figure 8 The signals at the cathode interface [DMPO-•H] and the anode interface [DMPO-•OH] (applied voltage = 3.5V) show strong ▪H and ▪OH signal peaks, indicating that strongly reducing ▪H and strongly oxidizing ▪OH free radicals are stably present in the system of this embodiment.

[0053] Figure 9 It is a bipolar membrane-mediated electrocatalytic reduction oxidation device for electrodes with different porosities, including 10µm, 50µm and 80µm, and the change of sodium dichlorophenate (DCF) concentration in deionized water over time.

[0054] Figure 10 This is a bipolar membrane-mediated electrocatalytic reduction oxidation device used to study the changes in sodium dichlorophenate (DCF) concentration over time in actual water bodies, including tap water, surface water, and marine aquaculture wastewater. Detailed Implementation

[0055] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. However, those skilled in the art will understand that this invention is not limited to the accompanying drawings and the following embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0056] Reference Figure 1-5 This embodiment proposes a bipolar membrane-mediated electrocatalytic reduction oxidation system, including a pump 1, a storage tank 2, a controllable power supply 3, and a bipolar membrane-mediated electrocatalytic reduction oxidation device 4.

[0057] The pump 1 is used to deliver water containing halogenated antibiotics to the electrocatalytic reduction oxidation device.

[0058] The storage tank 2 is used to store the water to be treated.

[0059] The controllable power supply 3 is used to supply power to the electrocatalytic reduction oxidation device, and the power supply voltage is adjustable.

[0060] The electrocatalytic reduction oxidation device 4 is used to treat the water containing the halogenated antibiotic.

[0061] Preferably, no additional electrolytes are added to the water to be treated.

[0062] The output voltage of the controllable power supply 3 is adjustable to regulate the applied voltage to the porous Ti4O7 bifunctional electrode and bipolar membrane, providing a stable and adjustable applied voltage to ensure that the bipolar membrane is under reverse bias and to maintain the electrocatalytic reduction and oxidation reactions.

[0063] The electrocatalytic reduction-oxidation device includes a cathode chamber 41, a first porous Ti4O7 bifunctional electrode 42, a first polytetrafluoroethylene (PTFE) gasket 43, a bipolar membrane 44, a second PTFE gasket 45, a second porous Ti4O7 bifunctional electrode 46, and an anode chamber 47, which are assembled sequentially. The cathode chamber 41 and the anode chamber 47 are connected, forming a cascade reaction pathway in which electrocatalytic reduction and electrocatalytic oxidation reactions occur, respectively. It should be noted that "sequential assembly" does not mean that the present invention is limited to adding other accessories to the electrocatalytic reduction-oxidation device; it only indicates the main core components and their arrangement included in the electrocatalytic reduction-oxidation device of this embodiment of the invention.

[0064] The cathode chamber 41 is used for the electrocatalytic reduction reaction of the halogenated antibiotic to generate a dehalogenated intermediate; the anode chamber 47 is used for the electrocatalytic oxidation reaction of the dehalogenated intermediate; the cathode chamber 41 and the anode chamber 47 are connected to form a cascade reaction pathway in which the electrocatalytic reduction reaction and the electrocatalytic oxidation reaction occur respectively.

[0065] The first porous Ti4O7 bifunctional electrode 42 is electrically connected to the negative terminal of the controllable power supply 3; the second porous Ti4O7 bifunctional electrode 46 is electrically connected to the positive terminal of the controllable power supply 3. Thus, under the applied voltage of the controllable power supply 3, the first porous Ti4O7 bifunctional electrode 42 and the second porous Ti4O7 bifunctional electrode 46 serve as the electrocatalytic reduction electrode and the electrocatalytic oxidation electrode, respectively, and also provide voltage to the bipolar membrane 44 located between them. The porous structure of the Ti4O7 bifunctional electrode allows the water to be treated to permeate. The pore size of the first porous Ti4O7 bifunctional electrode 42 is 10-80 μm, preferably 20-70 μm, 30-60 μm, or 40-50 μm, and most preferably 20 μm; the pore size of the second porous Ti4O7 bifunctional electrode 46 is 10-80 μm, preferably 20-70 μm, 30-60 μm, or 40-50 μm, and most preferably 20 μm. The thickness of the first porous Ti4O7 bifunctional electrode 42 is 0.5~3mm, preferably 0.6~2.9mm, 0.7~2.8mm, 0.8~2.6mm, 0.9~2.5mm, 1.0~2.4mm, 1.1~2.3mm, 1.2~2.2mm, 1.3~2.1mm, 1.4~2.0mm, 1.5~1.9mm, 1.6~1.8mm, and most preferably, the thickness of the first porous Ti4O7 bifunctional electrode 42 is 20μm. The thickness of the second porous Ti4O7 bifunctional electrode 42 is 0.5~3mm, preferably 0.6~2.9mm, 0.7~2.8mm, 0.8~2.6mm, 0.9~2.5mm, 1.0~2.4mm, 1.1~2.3mm, 1.2~2.2mm, 1.3~2.1mm, 1.4~2.0mm, 1.5~1.9mm, 1.6~1.8mm, and most preferably, the thickness of the second porous Ti4O7 bifunctional electrode 46 is 2mm. In one embodiment, using a porous Ti4O7 bifunctional electrode, if a DC controllable power supply with polarity switching function is used, or if an external circuit switching module is used to interchange the positive and negative connections of the electrode and the power supply, the long-term operational stability of the Ti4O7 electrode can be improved. The Ti4O7 bifunctional electrode used in this invention can be prepared using a plasma spraying process, such as... Figure 5 The porous Ti4O7 bifunctional electrode shown has a diameter of 25 cm, a pore size of 20 μm, and a thickness of 2 mm.

[0066] See Figure 4The first PTFE gasket 43 is used to isolate the first porous Ti4O7 bifunctional electrode 42 and the bipolar film 44; the second PTFE gasket 45 is used to isolate the second porous Ti4O7 bifunctional electrode 46 and the bipolar film 44. In one embodiment, the first PTFE gasket 43 has a mounting hole in its center for mounting the first porous Ti4O7 bifunctional electrode 42, and the second PTFE gasket 45 has a mounting hole in its center for mounting the second porous Ti4O7 bifunctional electrode 46. The main functions of the first PTFE gasket 43 and the second PTFE gasket 45 are to fix the electrodes, seal the reactor, adjust the thickness of the first PTFE gasket 43 and the second PTFE gasket 45, and respectively adjust the distance between the first porous Ti4O7 bifunctional electrode 42 and the second porous Ti4O7 bifunctional electrode 46 and the bipolar film 44. The thickness of the first polytetrafluoroethylene gasket 43 is 0.5~5mm, preferably 0.6~4.5mm, 0.7~4.0mm, 0.8~3.5mm, 0.9~2.5mm, 1.0~2.0mm, and most preferably, the thickness of the second polytetrafluoroethylene gasket 45 is 2mm; the thickness of the first polytetrafluoroethylene gasket 43 is 0.5~5mm, preferably 0.6~4.5mm, 0.7~4.0mm, 0.8~3.5mm, 0.9~2.5mm, 1.0~2.0mm, and most preferably, the thickness of the second polytetrafluoroethylene gasket 45 is 2mm.

[0067] The bipolar membrane 44 is used to dissociate water into H+. + and OH – They migrate to the cathode and anode respectively. The bipolar membrane 44 consists of an anion exchange layer, a cation exchange layer, and an intermediate interface layer, wherein the intermediate interface layer is a water dissociation catalyst. The thickness of the bipolar membrane is 50~300μm, preferably 60~290μm, 70~280μm, 80~270μm, 90~260μm, 100~250μm, 110~240μm, 120~230μm, 130~220μm, 140~210μm, 150~200μm, 160~190μm, 170~180μm, and most preferably, the thickness of the bipolar membrane 44 is 130μm. When the controllable power supply 3 is turned on, the bipolar membrane 44 can dissociate water into H+. + and OH – They migrate towards the anode and cathode respectively; simultaneously, water on both sides of the bipolar membrane 44 enters the intermediate interface layer through the cation exchange layer and anion exchange layer to replenish the water consumed. The H2 produced by the in-situ dissociation of water in the bipolar membrane 44... + / OH –It can act as an electrolyte ion to solve the technical problem of low conductivity in water with low concentration of electrolytes, thereby avoiding the need to add extra electrolytes; it can also make the cathode and anode work under their own ideal pH conditions by flexibly adjusting the pH of the electrode interfaces on both sides of the bipolar membrane 44, thus avoiding the need for external acid or alkali regulation.

[0068] The cathode chamber 41 has a cathode chamber inlet 411 and a cathode chamber outlet 412, and the anode chamber 47 has an anode chamber inlet 471 and an anode chamber outlet 472. The cathode chamber outlet is connected to the anode chamber inlet 471.

[0069] The cathode chamber 41 has a cathode chamber liquid flow passage for the water to be treated to flow therethrough, and the cathode chamber liquid flow passage is connected to the cathode chamber inlet 411 and the cathode chamber outlet 412, respectively. The halogenated antibiotics in the water to be treated undergo nucleophilic dehalogenation and reduction reaction in the cathode chamber 41 under the action of the first porous T4O7 bifunctional electrode 42, generating a dehalogenated intermediate; simultaneously, the bipolar membrane 44 catalyzes the dissociation of water to produce H₂. + H + Migration towards the cathode adjusts the pH and compensates for the lower conductivity in water bodies with low electrolyte concentrations. In one embodiment, such as Figure 2 As shown, the cathode chamber 41 is constructed as a semi-shell with a cathode chamber flow passage; preferably, the cathode chamber liquid flow passage is S-shaped.

[0070] The anode chamber 47 has an anode chamber liquid flow passage 460 for the flow of water to be treated therein, the anode chamber liquid flow passage 460 being connected to the anode chamber inlet 471 and the anode chamber outlet 472, respectively. The dehalogenated intermediates in the water to be treated are oxidized and decomposed in the anode chamber 47 under the action of the second porous T4O7 bifunctional electrode 42, undergoing an electrophilic reaction; simultaneously, the bipolar membrane 44 catalyzes the dissociation of water to produce OH-. – OH – The water migrates towards the anode, adjusting the pH and compensating for the lower conductivity in the water. The treated effluent is then discharged from the anode chamber outlet 472. In one embodiment, the anode chamber 47 is constructed as a semi-shell with an anode chamber flow passage 460; preferably, the anode chamber liquid flow passage 460 is S-shaped.

[0071] Thus, the cathode chamber 41 and the anode chamber 47 form a connected liquid flow path, constituting a cascade reaction path. The water to be treated enters the cathode chamber 41 through the inlet of the pump 1, undergoes electrochemical catalytic reduction, and then flows out from the cathode chamber outlet 412. It then enters the anode chamber 47 through the anode chamber inlet 471, undergoes electrochemical catalytic oxidation, and is discharged from the anode chamber outlet 472. Simultaneously with the electrochemical catalytic reduction and oxidation, the bipolar membrane 44 catalyzes the dissociation of water, generating H₂. + and OH – They migrate to the cathode and anode respectively to adjust the pH value and compensate for the low conductivity in water with low concentration of electrolytes, thereby enabling the technical solution of the present invention to be used for the removal of halogenated antibiotics in water with low conductivity.

[0072] The systems and apparatus of this invention are not limited to water containing halogenated antibiotics, but can also be used to treat other contaminated water. Due to the characteristics of the systems and apparatus of this invention, they are particularly advantageous when treating water containing halogenated antibiotics with low conductivity.

[0073] Reference Figure 1-5 This invention also proposes a method for treating halogenated antibiotics in water using a bipolar membrane-mediated electrocatalytic reduction oxidation. The method utilizes an electrocatalytic reduction oxidation device comprising a cathode chamber 41, a first porous Ti4O7 bifunctional electrode 42, a first polytetrafluoroethylene (PTFE) gasket 43, a bipolar membrane 44, a second PTFE gasket 45, a second porous Ti4O7 bifunctional electrode 46, and an anode chamber 47, assembled sequentially. The cathode chamber 41 and the anode chamber 47 are connected, forming a cascade reaction pathway where electrocatalytic reduction and electrocatalytic oxidation reactions occur respectively. The method includes the following steps:

[0074] (S1) The halogenated antibiotic in the water to be treated is electrocatalytically reduced and dehalogenated in the cathode chamber 41 to generate a dehalogenated intermediate. The bipolar membrane 44 catalyzes the dissociation of water to produce H2O. + ;

[0075] (S2) The water to be treated, containing the dehalogenated intermediate, flows from the cathode chamber 41 into the anode chamber 47;

[0076] (S3) The dehalogenated intermediate in the water to be treated is electrocatalytically oxidized and decomposed in the anode chamber 47, and the bipolar membrane 44 catalyzes the dissociation of water to produce OH-. – ;

[0077] (S4) The treated water is discharged from the outlet 472 of the anode chamber.

[0078] The current density through the first porous Ti4O7 bifunctional electrode 42 ranges from 1 to 100 A / m. 2 Preferably 1-100A / m 2 5-90A / m 2 10-80A / m 2 15-70A / m 2 20-60A / m 2 30-50A / m 2 Most preferably, the current density through the first porous Ti4O7 bifunctional electrode 42 is 40 A / m. 2 The current density of the second porous Ti4O7 bifunctional electrode 42 ranges from 1 to 100 A / m. 2 Preferably 1-100A / m 2 5-90A / m 2 10-80A / m 2 15-70A / m 2 20-60A / m 2 30-50A / m 2 Most preferably, the current density through the second porous Ti4O7 bifunctional electrode 46 is 40 A / m. 2 .

[0079] Example 1: Water quality indicators of water to be treated containing halogenated antibiotics: water conductivity 0.1 μS / cm, sodium diclofenac (DCF) concentration 1.00 mg / L, sulfamethoxazole (SMX) concentration 1.00 mg / L, pH 7.14.

[0080] Key parameters of a bipolar membrane-mediated electrocatalytic reduction-oxidation system:

[0081] The first porous Ti4O7 bifunctional electrode 42 has a pore size of 20 μm, a thickness of 2 mm, and a current density of 40 A / m².

[0082] The second porous Ti4O7 bifunctional electrode 46 has a pore size of 20 μm, a thickness of 2 mm, and a current density of 40 A / m².

[0083] Bipolar membrane: 130μm thick. Purchased from Hangzhou Lanran Technology Co., Ltd., model: Bipolar membrane BP-2.

[0084] The thickness of the first polytetrafluoroethylene gasket 43 is 2 mm, and the thickness of the second polytetrafluoroethylene gasket 45 is 2 mm.

[0085] Reference Figure 1-6 The water containing halogenated antibiotics was treated using the bipolar membrane-mediated electrocatalytic reduction oxidation system described above. The specific steps are as follows:

[0086] (S1) Cathode Chamber Treatment: The water to be treated is pumped into the cathode chamber 41 at a rate of 50 mL / min using pump 1. The halogenated antibiotics in this low-conductivity water are electrocatalytically reduced within the cathode chamber 41 under the action of the first porous T4O7 bifunctional electrode 42, undergoing nucleophilic dehalogenation to obtain a dehalogenation intermediate. Simultaneously, the water to be treated permeates through the first porous T4O7 bifunctional electrode 42 and the first polytetrafluoroethylene gasket 43. Under the catalysis of the bipolar membrane 44, the water dissociates to produce H₂. + H + The flow rate of the water to be treated is not limited to this speed. By increasing the effective reaction area of ​​the porous T4O7 bifunctional electrode, increasing the processing flow rate of a single module, or by using multiple electrocatalytic reduction oxidation modules in series, the overall processing capacity of the system can be easily scaled up linearly. This scale-up method is a conventional engineering technique in the field of electrochemical reactors.

[0087] (S2) Under the action of pump 1, the water to be treated containing the dehalogenation intermediate enters the anode chamber 47 from the cathode chamber drain port 412 and the anode chamber inlet port 471;

[0088] (S3) Anode Chamber Treatment: The dehalogenated intermediate in the water to be treated is oxidized and decomposed by •OH generated under the action of the second porous T4O7 bifunctional electrode 42 in the anode chamber 47, undergoing an electrophilic reaction. At the same time, the water to be treated permeates through the second porous T4O7 bifunctional electrode 46 and the second polytetrafluoroethylene gasket 45, and under the catalysis of the bipolar membrane 44, the water dissociates to produce OH. – OH – They migrate toward the anode, adjusting the pH and compensating for the lower conductivity in the water.

[0089] (S4) The treated water is discharged from the outlet 472 of the anode chamber.

[0090] Comparative Example 1

[0091] The processing method is basically the same as in Example 1, except that the bipolar membrane in the electrocatalytic reduction oxidation device is replaced with a proton exchange membrane.

[0092] Comparative Example 2

[0093] The processing method is the same as in Example 1, except that the electrocatalytic reduction oxidation device does not have a bipolar membrane.

[0094] The treatment results of the water containing halogenated antibiotics in the examples and comparative examples are shown in the table below:

[0095] Experimental results show that the bipolar membrane (BPM) dielectric catalytic reduction oxidation system of this invention can still effectively degrade low concentrations of halogenated antibiotics in water under low electrolyte concentration conditions, and can operate stably at low operating voltage, demonstrating the good conductivity of the system and helping to improve the efficiency of electrochemical reactions in water with low conductivity.

[0096] Example 2: Refer to Figure 8 The water quality parameters for the water to be treated, containing halogenated antibiotics, were as follows: sodium diclofenac (DCF) concentration of 1.00 mg / L, water source from deionized water, and an electrode with a porosity of 20 µm. The treatment system and method used were basically the same as in Example 1.

[0097] Comparative Example 3

[0098] The processing method is basically the same as in Example 2, except that a 10µm electrode is used.

[0099] Comparative Example 4

[0100] The processing method is basically the same as in Example 2, except that a 50µm electrode is used.

[0101] Comparative Example 5

[0102] The processing method is basically the same as in Example 2, except that an 80µm electrode is used.

[0103] The treatment results of the water containing halogenated antibiotics in the examples and comparative examples are shown in the table below:

[0104] Experimental results show that when the electrode pore diameter is 20µm, the bipolar membrane (BPM) dielectric catalytic reduction oxidation system of this invention has the lowest operating voltage while ensuring effective degradation performance, thereby significantly reducing the energy consumption of the system.

[0105] Example 3

[0106] Reference Figure 9 The water quality parameters for the water to be treated, containing halogenated antibiotics, were as follows: sodium diclofenac (DCF) concentration of 1.00 mg / L, and the water source was ordinary tap water (150 µS / cm). The treatment system and method used were basically the same as in Example 1, except for the water source.

[0107] Comparative Example 6

[0108] The treatment method is basically the same as in Example 2, except that the water source is surface water - effluent from a sewage treatment plant (230µS / cm).

[0109] Comparative Example 7

[0110] The treatment method is basically the same as in Example 2, except that the water source is seawater (3000 µS / cm) from a marine aquaculture farm in Yantai.

[0111] The treatment results of the water containing halogenated antibiotics in the examples and comparative examples are shown in the table below:

[0112] Experimental results show that the bipolar membrane (BPM) mediated electrocatalytic reduction oxidation system of this invention can effectively degrade low concentrations of halogenated antibiotics in water with different water qualities, and the effect is significant.

[0113] The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A bipolar membrane-mediated electrocatalytic reduction-oxidation device for water treatment, characterized in that, It includes a cathode chamber, a first porous Ti4O7 bifunctional electrode, a first polytetrafluoroethylene gasket, a bipolar membrane, a second polytetrafluoroethylene gasket, a second porous Ti4O7 bifunctional electrode, and an anode chamber, which are assembled in sequence. The cathode chamber and the anode chamber are connected, forming a cascade reaction pathway in which electrocatalytic reduction and electrocatalytic oxidation reactions occur respectively; The first porous Ti4O7 bifunctional electrode and the second porous Ti4O7 bifunctional electrode are respectively used to be electrically connected to the power supply, so that electrocatalytic reactions can occur in the cathode chamber and the anode chamber respectively, and provide voltage to the bipolar membrane; The bipolar membrane is used to dissociate water into H+. + and OH – And migrate towards the cathode and anode respectively; The first polytetrafluoroethylene gasket is used to isolate the first porous Ti4O7 bifunctional electrode and the bipolar membrane; the second polytetrafluoroethylene gasket is used to isolate the second porous Ti4O7 bifunctional electrode and the bipolar membrane.

2. The electrocatalytic reduction apparatus as described in claim 1, characterized in that, The cathode chamber is used for the electrocatalytic reduction of halogenated antibiotics in the water to be treated under the action of the first porous T4O7 bifunctional electrode to generate a dehalogenated intermediate; the anode chamber is used for the electrocatalytic oxidation of the dehalogenated intermediate under the action of the second porous T4O7 bifunctional electrode.

3. The electrocatalytic reduction apparatus as described in claim 1 or 2, characterized in that, The cathode chamber has a cathode chamber inlet and a cathode chamber outlet, and the anode chamber has an anode chamber inlet and an anode chamber outlet. The cathode chamber outlet is connected to the anode chamber inlet.

4. The electrocatalytic reduction apparatus as described in claim 3, characterized in that, The cathode chamber has a cathode chamber liquid flow passage for the water to be treated to flow therein, and the cathode chamber liquid flow passage is connected to the cathode chamber inlet and the cathode chamber outlet respectively; the anode chamber has an anode chamber liquid flow passage for the water to be treated to flow therein, and the anode chamber liquid flow passage is connected to the anode chamber inlet and the anode chamber outlet respectively.

5. The electrocatalytic reduction apparatus as described in claim 4, characterized in that, The cathode chamber is constructed as a semi-shell with a cathode chamber flow path; the anode chamber is constructed as a semi-shell with an anode chamber flow path. Preferably, the liquid flow path in the anode chamber is S-shaped; preferably, the liquid flow path in the cathode chamber is S-shaped.

6. The electrocatalytic reduction apparatus as described in claim 1, characterized in that, The first porous Ti4O7 bifunctional electrode is electrically connected to the negative terminal of the controllable power supply; the second porous Ti4O7 bifunctional electrode is electrically connected to the positive terminal of the controllable power supply. Preferably, the pore size of the first porous Ti4O7 bifunctional electrode is 10-80 μm, more preferably 20-70 μm, 30-60 μm, or 40-50 μm, and most preferably 20 μm; the pore size of the second porous Ti4O7 bifunctional electrode is 10-80 μm, more preferably 20-70 μm, 30-60 μm, or 40-50 μm, and most preferably 20 μm; and / or, The thickness of the first porous Ti4O7 bifunctional electrode is 0.5~3 mm, preferably 0.6~2.9 mm, 0.7~2.8 mm, 0.8~2.6 mm, 0.9~2.5 mm, 1.0~2.4 mm, 1.1~2.3 mm, 1.2~2.2 mm, 1.3~2.1 mm, 1.4~2.0 mm, 1.5~1.9 mm, 1.6~1.8 mm, and most preferably, the thickness of the first porous Ti4O7 bifunctional electrode is 2 mm; and / or, The thickness of the second porous Ti4O7 bifunctional electrode is 0.5~3mm, preferably 0.6~2.9mm, 0.7~2.8mm, 0.8~2.6mm, 0.9~2.5mm, 1.0~2.4mm, 1.1~2.3mm, 1.2~2.2mm, 1.3~2.1mm, 1.4~2.0mm, 1.5~1.9mm, 1.6~1.8mm, and most preferably, the thickness of the second porous Ti4O7 bifunctional electrode is 2mm.

7. The electrocatalytic reduction apparatus as described in claim 1, characterized in that, The first PTFE gasket has a mounting hole in its center for mounting the first porous Ti4O7 bifunctional electrode, and the second PTFE gasket has a mounting hole in its center for mounting the second porous Ti4O7 bifunctional electrode. And / or, The thickness of the first PTFE gasket is 0.5~5 mm, preferably 0.6~4.5 mm, 0.7~4.0 mm, 0.8~3.5 mm, 0.9~2.5 mm, or 1.0~2.0 mm, and most preferably, the thickness of the second PTFE gasket is 2 mm. And / or, The thickness of the first PTFE gasket is 0.5~5 mm, preferably 0.6~4.5 mm, 0.7~4.0 mm, 0.8~3.5 mm, 0.9~2.5 mm, or 1.0~2.0 mm, and most preferably, the thickness of the second PTFE gasket is 2 mm. And / or, The thickness of the bipolar film is 50~300μm, preferably 60~290μm, 70~280μm, 80~270μm, 90~260μm, 100~250μm, 110~240μm, 120~230μm, 130~220μm, 140~210μm, 150~200μm, 160~190μm, 170~180μm, and most preferably 130μm.

8. The electrocatalytic reduction apparatus as described in claim 1, characterized in that, No additional electrolytes are added to the water.

9. A bipolar membrane-mediated electrocatalytic reduction-oxidation system, characterized in that, Includes a pump, a storage tank, a controllable power supply, and an electrocatalytic reduction oxidation device as described in any one of claims 1-8; The pump is used to deliver water to be treated to the electrocatalytic reduction oxidation device; The storage tank is used to store the water to be treated; The controllable power supply is used to power the electrocatalytic reduction oxidation device, and the power supply voltage is adjustable.

10. A method for treating halogenated antibiotics in water by bipolar membrane-mediated electrocatalytic reduction oxidation, the method utilizing an electrocatalytic reduction oxidation device comprising, in sequence, a cathode chamber, a first porous Ti4O7 bifunctional electrode, a first polytetrafluoroethylene (PTFE) gasket, a bipolar membrane, a second PTFE gasket, a second porous Ti4O7 bifunctional electrode, and an anode chamber, wherein the cathode chamber and the anode chamber are connected, configured as a cascade reaction pathway in which electrocatalytic reduction and electrocatalytic oxidation reactions occur respectively, the method comprising the following steps: (S1) The halogenated antibiotic in the water to be treated is electrocatalytically reduced and nucleophilically dehalogenated in the cathode chamber to generate a dehalogenated intermediate. The bipolar membrane catalyzes the dissociation of water to produce H2O. + ; (S2) The water to be treated, containing the dehalogenated intermediate, flows from the cathode chamber into the anode chamber; (S3) The dehalogenated intermediate in the water to be treated is electrocatalytically oxidized and decomposed in the anode chamber, and the bipolar membrane catalyzes the dissociation of water to produce OH-. – ; (S4) The treated water is discharged from the outlet of the anode chamber. Preferably, the current density through the first porous Ti4O7 bifunctional electrode is in the range of 1-100 A / m. 2 Preferably 1-100A / m 2 5-90A / m 2 10-80A / m 2 15-70A / m 2 20-60A / m 2 30-50A / m 2 Most preferably, the current density through the first porous Ti4O7 bifunctional electrode is 40 A / m. 2 Preferably, the current density of the second porous Ti4O7 bifunctional electrode is in the range of 1-100 A / m. 2 Preferably 1-100A / m 2 5-90A / m 2 10-80A / m 2 15-70A / m 2 20-60A / m 2 30-50A / m 2 Most preferably, the current density through the second porous Ti4O7 bifunctional electrode is 40 A / m. 2 .

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