A flow type photoelectric synergistic catalytic filtration system for removing new contaminant wastewater by high-efficiency activated molecular oxygen and application thereof

Abstract

This invention discloses a flow-through photoelectric synergistic catalytic filtration system for efficiently activating molecular oxygen to remove novel pollutants from wastewater. It possesses multiple advantages, including efficient activation of molecular oxygen, photo-electric synergistic enhancement, and enhanced mass transfer through a flow system, thus facilitating the efficient removal of novel pollutants. The flow-through photoelectric synergistic catalytic filtration system comprises a shell, anode and cathode electrodes, and a separator. The shell contains, in sequence, an anode, a non-woven fabric separator, a cathode, and a sealing ring. The anode is a bismuth oxybromine / carbon nitride / smarium-vanadate photoelectrode, and the cathode is a cobalt-iron two-atom confined carbon nanotube electrode. Its broad-spectrum responsive materials and novel catalyst design significantly improve anti-interference capabilities, adapting to complex water quality and low-concentration pollution scenarios. Novel pollutant wastewater can be efficiently removed in this flow-through photoelectric synergistic catalytic filtration system after being irradiated and electrolyzed in a circulating flow mode. The removal rate of ibuprofen can reach 96% within 2 hours. This invention features a simple design, is easy to operate, has low cost and low energy consumption, and solves the problems of low removal efficiency and high energy consumption in ordinary treatment systems. At the same time, it combines the full spectrum utilization of solar energy and a low catalyst dosage design to further reduce operating costs, demonstrating comprehensive advantages of high efficiency, stability, economy and environmental protection.

Description

Technical Field

[0001] This invention relates to a flow-through photoelectric co-catalytic filtration system for removing new pollutants from wastewater by activating molecular oxygen and its application, particularly to a flow-through photoelectric co-catalytic filtration system for treating new pollutants from wastewater by activating molecular oxygen in the air, belonging to the fields of photoelectrochemistry and water treatment technology. Background Technology

[0002] The global aquatic environment currently faces a severe challenge from emerging pollutants (covering over 120,000 trace organic compounds, including perfluorinated compounds, pharmaceuticals, and endocrine disruptors). These pollutants are characterized by chemical diversity, environmental persistence, and bioaccumulation, resulting in conventional physicochemical treatment technologies achieving removal rates of less than 40%, and also suffering from limitations such as high energy consumption and secondary pollution. These pollutants can threaten aquatic ecosystems and human health at concentrations in the ng / L range, and the associated treatment costs are increasing year by year. Therefore, there is an urgent need to develop innovative technologies that are highly efficient in degradation, low in cost, and free from secondary pollution, to address the core challenges of detecting, removing, and controlling these emerging pollutants.

[0003] Advanced oxidation techniques can be used to activate molecular oxygen to produce reactive oxygen species (ROS), which, through energy input (light, electricity, or heat), convert ground-state molecular oxygen into highly reactive singlet oxygen. 1 Oxygen spores (ROS) include superoxide radicals (·O2-) and hydroxyl radicals (·OH). These ROS possess strong oxidizing properties and can efficiently degrade organic pollutants. In recent years, photoelectrocatalysis technology has been widely used in the field of pollutant treatment due to its dual advantages of photocatalysis and electrocatalysis. Green oxidation technology, which utilizes light and electrical energy to drive molecular oxygen activation, generates photogenerated electron-hole pairs under light irradiation through photoelectrocatalysts, which then react with molecular oxygen to generate ROS, achieving the deep treatment of new pollutant wastewater.

[0004] However, conventional photoelectrocatalytic systems for treating novel pollutants are limited by low light energy utilization efficiency, poor catalyst activity and stability, difficulty in controlling intermediate products, system design flaws, and bottlenecks in large-scale application. This results in low treatment efficiency, high costs, and difficulty in achieving long-term stable operation. There is an urgent need to overcome these technical bottlenecks through strategies such as high-efficiency catalyst design, optical near-field catalysis technology, and reactor optimization. The oxygen-self-supplied fluid bipolar electrochemical filtration system invented by Liu Yanbiao et al. includes a shell, a reference electrode, and a titanium ring, anode, polytetrafluoroethylene membrane, cathode, and titanium sheet arranged sequentially inside the shell. After being connected to a three-electrode system, it removes organic micro-pollutants through electrolytic treatment, solving the problems of long reaction time, numerous byproducts, and high energy consumption (Patent No. 117699920A). However, the single catalytic mode of the electrocatalytic system has low efficiency and insufficient treatment depth, while also consuming a large amount of external energy, resulting in low utilization efficiency. Therefore, the existing photoelectrocatalytic systems for removing new pollutants still have the following disadvantages: (1) The static reaction tank design results in low mass transfer efficiency and slow diffusion of reactants, which limits the reaction activity; (2) Byproducts are easily accumulated on the catalyst surface, resulting in poor catalyst stability and shortened lifespan; (3) The system design has low integration, is inconvenient to operate, and has high application costs.

[0005] Therefore, it is of great significance to develop a flow-through photoelectric co-catalytic filtration system and use it to efficiently activate molecular oxygen to remove new pollutants from wastewater. Summary of the Invention

[0006] The purpose of this invention is to provide a flow-through photoelectric synergistic catalytic filtration system for efficiently activating molecular oxygen to remove new pollutants from wastewater. This system is simple in design, easy to operate, low in cost and energy consumption, and has multiple advantages such as efficient activation of molecular oxygen, photo-electric synergistic enhancement and enhanced mass transfer in the flow system, which is conducive to achieving efficient removal of new pollutants.

[0007] The objective of this invention is achieved through the following technical solution:

[0008] A flow-through photoelectric synergistic catalytic filtration system for efficiently activating molecular oxygen to remove new pollutants from wastewater is characterized by comprising a shell, anode and cathode electrodes, and a separator, wherein the shell is sequentially configured with an anode, a non-woven fabric separator, a cathode, and a sealing ring.

[0009] Preferably, the anode is a bismuth oxybromo / carbon nitride / smarium-vanadate photoelectrode, and the cathode is a cobalt-iron diatomic confined carbon nanotube electrode.

[0010] Preferably, the structure of the bismuth oxybromide / carbon nitride / bismuth samarium vanadate photoanode is a double Z-type heterojunction, and it has full-spectrum response capability.

[0011] Preferably, the preparation method of the bismuth oxybromine / carbon nitride / smarium-bismuth vanadate photoanode includes the following steps: a two-electrode DC current system with a titanium mesh as the cathode and a platinum sheet as the anode, and acetone and iodine solution as the electrolyte solution, wherein bismuth oxybromine / carbon nitride / smarium-bismuth vanadate is loaded in layers by electrodeposition on the surface of the titanium mesh;

[0012] The concentrations of bismuth oxybromide, carbon nitride, and bismuth samarium-vanadate in the electrolyte solution are 0.1–0.5 g / L, and the concentration of iodine is 0.3–0.5 g / L.

[0013] The electrodeposition voltage is 15–32V, and the electrodeposition time is 1–5 minutes.

[0014] Preferably, the preparation method of the cobalt-iron two-atom confined carbon nanotube electrode includes the following steps:

[0015] (1) A cobalt-iron diatomic confined carbon nanotube catalyst was obtained by mixing a nitrogen source and a metal salt solution, drying and then calcining at high temperature.

[0016] (2) Cobalt-iron diatomic confined carbon nanotube powder was loaded onto a carbon felt to obtain a cobalt-iron diatomic confined carbon nanotube electrode.

[0017] Preferably, in the preparation method of the cobalt-iron two-atom confined carbon nanotube electrode, the metal salt solution includes iron nitrate and cobalt nitrate solutions, and the solvent of the metal salt solution includes pure water or ethanol;

[0018] The amount of cobalt and iron added to the metal salt solution is 0.5 wt% to 4 wt% of the nitrogen source;

[0019] The high-temperature calcination temperature is 600–900℃, and the calcination time is 2–4 hours.

[0020] Preferably, the end of the housing near the cathode is provided with a water inlet, and the end of the housing near the anode is provided with a water outlet.

[0021] This invention also provides an application of the above-mentioned flow-through photoelectric synergistic catalytic filtration system in the treatment of new pollutant wastewater, and the specific application method is as follows:

[0022] The new pollutant wastewater and sulfate are mixed to obtain mixed wastewater. The mixed wastewater is then passed into the above-mentioned flow-through photoelectric synergistic catalytic filtration system for irradiation and electrostatic treatment in a circulating flow mode to remove the new pollutants.

[0023] Preferably, the new pollutant comprises one or more of ibuprofen, bisphenol A, phthalates and sulfamethoxazole, and the concentration of the new pollutant in the mixed wastewater is 1-20 mg / L; the concentration of sulfate in the mixed wastewater is 0.05-0.1 mol / L.

[0024] Preferably, the current density of the energizing process is 0.5–4 mA / cm². 2 The power-on treatment time is 0.5–1 hour; the light intensity is 0.2–1 kW / cm². 2 The illumination time is 0.5 to 1 hour.

[0025] The flow rate of the mixed wastewater into the flow-through photoelectric synergistic catalytic filtration system is 1–5 mL / min.

[0026] Compared with the prior art, the present invention has the following advantages:

[0027] (1) The flow-through photoelectric synergistic catalytic filtration system overcomes the efficiency bottleneck of a single catalytic mode by enhancing mass transfer through photo-electric synergistic enhancement and flow system, and achieves efficient degradation of new pollutants;

[0028] (2) Its wide-spectrum response materials and novel catalyst design significantly improve anti-interference ability and adapt to complex water quality and low-concentration pollution scenarios;

[0029] (3) At the same time, the design of full-spectrum solar energy utilization and low catalyst usage further reduces operating costs, demonstrating the comprehensive advantages of high efficiency, stability, economy and environmental protection. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the flow-through photoelectric synergistic catalytic filtration system described in this invention;

[0031] Figure 2 The graph shows the degradation efficiency of ibuprofen in water by the system in Experiment Example 1. Detailed Implementation

[0032] To facilitate understanding by those skilled in the art, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] Example 1

[0034] (1) Preparation of bismuth oxybromide / carbon nitride / smarium-bismuth vanadate photoelectrode: 5 mmol Bi(NO3)3·5H2O was added to 10 mL CH3COOH and stirred for 25 min at room temperature to obtain precursor A; the corresponding molar amount of NH4VO3 was added to 60 mL deionized water and stirred in an 80℃ water bath until completely dissolved to obtain a transparent chrysanthemum-colored liquid to prepare precursor B; B was added to A to form an orange-chrysanthemum-colored suspension, and then 4 wt% of 0.05 mol / L Sm(NO3)3·6H2O solution was added. The pH of the mixed solution was adjusted to 7 with 1 mol / L NaOH. After magnetic stirring for 30 min, it was transferred to a 100 mL hydrothermal reactor and hydrothermally reacted under optimized process. After filtration, it was washed three times alternately with deionized water and anhydrous ethanol, dried at 60℃, and finally annealed in a tube furnace at 300℃ for 2 h to obtain samarium-bismuth vanadate powder. Three photoanode materials (bismuth oxybromide, carbon nitride, and samarium-bismuth vanadate) were dispersed in 35 mL of acetone solution, and 50 mg of iodine was added for ultrasonic dispersion. The materials were then sequentially deposited layer by layer onto a titanium mesh under a constant voltage of 32 V, with each layer electrodeposited for 1 min. After deposition, the electrode sheets were dried in an oven to obtain a bismuth oxybromide / carbon nitride / samarium-bismuth vanadate photoelectrode.

[0035] (2) Preparation of cobalt-iron diatom-confined carbon nanotube electrode: 20g of melamine was dissolved in 100mL of ethanol, and then 0.723g of Fe(NO3)3·9H2O and 0.412g of Co(NO3)2·6H2O were added to the ethanol solution. The mixture was stirred for 2h to fully dissolve and load the precursor solution. The thoroughly mixed precursor solution was heated in a water bath at 60℃ to evaporate the ethanol. After evaporation to dryness, the precursor material was dried in a forced-air drying oven at 60℃ for 12h to obtain the precursor material. Finally, the obtained precursor material was placed in a tube furnace under a nitrogen atmosphere and calcined at 700℃ for 2h to obtain the cobalt-iron diatom-confined carbon nanotube catalyst. 30mg of the cobalt-iron diatom-confined carbon nanotube catalyst was weighed and ultrasonically dispersed in a water-Nafion solution. The catalyst was then uniformly coated onto a carbon felt to prepare the cobalt-iron diatom-confined carbon nanotube electrode.

[0036] (3) Assembly of the flow-through photoelectric synergistic catalytic filtration system: The bismuth oxybromide / carbon nitride / smarium-bismuth vanadate photoelectrode prepared in step (1) is used as the anode, and the cobalt-iron two-atom confined carbon nanotube electrode prepared in step (2) is used as the cathode to assemble the flow-through photoelectric synergistic catalytic filtration system. Specifically, the anode, non-woven fabric partition, cathode, and sealing ring are sequentially arranged in the shell, and an inlet is set at the end of the shell near the cathode, and an outlet is set at the end of the shell near the anode. The photoelectric synergistic catalytic filtration system is powered by a two-electrode DC system and a xenon lamp. The wires set at both ends of the inlet and outlet are connected to the working electrode clamps of the two-electrode system, and then the anode and cathode are connected to be energized. The xenon lamp irradiates the upper end of the anode placement side.

[0037] Experimental Example 1

[0038] The anode and cathode prepared in Example 1 and the assembled flow-through photoelectrocatalytic filtration system were used to treat wastewater containing a novel pollutant, ibuprofen, at a concentration of 20 mg / L. Sodium sulfate was also added to the wastewater to achieve a molar concentration of 0.05 mol / L, and the current density was set to 4 mA / cm². 2 The total reaction time was 2 hours. A circulating flow operation mode was used to treat the wastewater. The mixed liquid was introduced into the inlet of the flow-through photoelectric synergistic catalytic filtration system, first flowing through the cathode, then through the anode. The effluent flowed into a beaker, and a peristaltic pump continuously returned the mixed liquid in the beaker to the cathode. Experimental results (e.g.) Figure 2 As shown in the figure, the flow-through photoelectric co-catalytic filtration system can achieve a removal rate of 96% for ibuprofen, a typical new pollutant, within 2 hours.

Claims

1. A flow-through photoelectric co-catalytic filtration system for efficiently removing new pollutants from wastewater by activating molecular oxygen, characterized in that: It includes a shell, a cathode, an anode, and a separator. The shell is sequentially configured with an anode, a non-woven fabric separator, a cathode, and a sealing ring. The anode is a bismuth oxybromine / carbon nitride / smarium-bismuth vanadate photoelectrode, and the cathode is a cobalt-iron two-atom confined carbon nanotube electrode. The structure of the bismuth oxybromide / carbon nitride / smarium-vanadate photoanode is a double Z-type heterojunction, and it has full-spectrum response capability; The preparation method of bismuth oxybromine / carbon nitride / smarium-bismuth vanadate photoanode includes the following steps: a two-electrode DC current system with a titanium mesh as the cathode and a platinum sheet as the anode, and acetone and iodine solution as the electrolyte solution, and layered electrodeposition of bismuth oxybromine / carbon nitride / smarium-bismuth vanadate on the surface of the titanium mesh; The preparation method of cobalt-iron two-atom confined carbon nanotube electrode includes the following steps: (1) Melamine and metal salt solution were mixed, dried and then calcined at high temperature to obtain cobalt-iron two-atom confined carbon nanotube catalyst; (2) Cobalt-iron diatomic confined carbon nanotube powder was loaded onto carbon felt to obtain cobalt-iron diatomic confined carbon nanotube electrode.

2. The flow-through photoelectric co-catalytic filtration system for removing new pollutants from wastewater with highly efficient activated molecular oxygen as described in claim 1, characterized in that: The shell has an inlet at the end near the cathode and an outlet at the end near the anode.

3. The flow-through photoelectric co-catalytic filtration system for removing new pollutants from wastewater with highly efficient activated molecular oxygen as described in claim 1, characterized in that: The concentration of iodine is 0.3~0.5 g / L, the electrodeposition voltage is 15~32 V, and the electrodeposition time is 1~5 min.

4. The flow-through photoelectric co-catalytic filtration system for removing new pollutants from wastewater with highly efficient activated molecular oxygen as described in claim 1, characterized in that: The metal salt solution includes ferric nitrate and cobalt nitrate solutions, and the solvent for the metal salt solution includes pure water or ethanol; the amount of cobalt and iron added in the metal salt solution is 0.5 wt% to 4 wt% of melamine; the high-temperature calcination temperature is 600 to 900°C, and the calcination time is 2 to 4 h.

5. An application of the flow-through photoelectric synergistic catalytic filtration system according to any one of claims 1-4 in the treatment of new pollutant wastewater, wherein the specific application method is as follows: the new pollutant wastewater and sulfate are mixed to obtain mixed wastewater, and the mixed wastewater is passed into the flow-through photoelectric synergistic catalytic filtration system according to any one of claims 1-4 for irradiation and electro-treatment to remove the new pollutants in a circulating flow mode.

6. The application of the flow-through photoelectric co-catalytic filtration system as described in claim 5 in the treatment of new pollutant wastewater, characterized in that: The new pollutant includes one or more of ibuprofen, bisphenol A, phthalates and sulfamethoxazole, and the concentration of the new pollutant in the mixed wastewater is 1~20 mg / L, and the concentration of sulfate in the mixed wastewater is 0.05~0.1 mol / L.

7. The application of the flow-through photoelectric co-catalytic filtration system as described in claim 5 in the treatment of new pollutant wastewater, characterized in that: The current density for the energizing process is 0.5~4 mA / cm². 2 The power treatment time is 0.5~1 h, the light irradiation time is 0.5~1 h, and the flow rate of the mixed wastewater into the flow-through photoelectric synergistic catalytic filtration system is 1~5 mL / min.

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