A method and device for treating wastewater by photoelectric field reinforced iron-carbon based catalytic oxidation

Abstract

The application discloses a kind of photoelectric field reinforced iron-carbon-based catalytic oxidation wastewater treatment method and device, it is related to wastewater treatment technical field, including the following steps: S1: wastewater enters water distribution room, and initial pH value is adjusted;S2: adjusted wastewater enters catalytic oxidation chamber and carries out oxygenation to wastewater, and purification is carried out under the synergistic effect of iron-carbon material and ultraviolet light;S3: wastewater enters electric field room, and strong oxidizing substance is generated, directly oxidizes pollutant, and through electrochemical effect, promote the conversion and removal of nitrogen, while strengthening the cycle of iron ion and phosphorus precipitation reaction.The application realizes the efficient removal of COD, ammonia nitrogen and total phosphorus in water by the synergistic effect of oxidation-reduction effect, adsorption effect of iron-carbon-based catalytic material, photocatalysis cooperation of ultraviolet light and electrochemical reaction of electric field.And through aeration mechanism, the contact adsorption effect of wastewater and catalytic material is improved, and the effect of wastewater treatment by ultraviolet light and catalytic material cooperation is also improved.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, and in particular to a photoelectric field-enhanced iron-carbon-based catalytic oxidation wastewater treatment method and apparatus. Background Technology

[0002] In the field of wastewater treatment, high-concentration, recalcitrant organic wastewater typically has a COD exceeding 10,000 mg / L. For this type of high-concentration organic wastewater, which also contains toxic and harmful substances, commonly used treatment methods include physicochemical methods, membrane methods, and biological methods. Physicochemical methods include micro-electrolysis and Fenton oxidation; membrane methods include ultrafiltration and nanofiltration; and biological treatment technologies include aerobic and anaerobic treatment.

[0003] Current physicochemical methods involve large investments, high costs, limited treatment effects, and poor shock resistance. High concentrations require large amounts of oxidants and may also cause secondary pollution. Membrane methods have high requirements for influent water quality, require huge investments, have low recycling rates, and are prone to fouling and clogging, resulting in short lifespans. Biological treatment technologies are limited by organic matter concentrations, microorganisms have low adaptability to changes in water quality and quantity, nitrogen and phosphorus removal are unsatisfactory, and pollutants in high-concentration, recalcitrant organic wastewater can prevent traditional biological treatment technologies from operating normally for extended periods.

[0004] Iron-carbon packing is the most commonly used iron-carbon based heterogeneous material in micro-electrolysis, but its main problem is easy caking. During long-term operation, Fe²⁺… + Fe³ + The generated hydroxides adhere to the packing surface, forming a passivation layer, leading to a decrease in reaction efficiency. Regular backwashing or packing replacement is necessary. Electrolytic iron-carbon based heterogeneous materials require an acidic pH of 2-3 to operate. Organic matter removal efficiency is low; its main function is to open rings and break chains of organic matter in wastewater. The Fenton oxidation method requires the addition of large amounts of H₂O₂ and FeSO₄, resulting in operating costs as high as 5-20 yuan / ton of wastewater. It also produces a large amount of sludge, increasing sludge treatment costs. It requires first adjusting the pH to 2-3 with acid, followed by neutralization with alkali, resulting in high consumption of acid and alkali reagents. H₂O₂ is a strong oxidizing agent and is prone to decomposition and explosion at high temperatures and with metallic impurities, requiring specialized storage tanks and incurring high storage and transportation costs. If the wastewater contains Cl₂... - (Concentration > 1000 mg / L), ·OH will react with Cl. - The reaction produces Cl2 and ClO. - These substances not only consume ·OH but may also generate halogenated byproducts such as chloroform, increasing toxicity.

[0005] Therefore, existing technologies for treating high-concentration, recalcitrant organic wastewater generally have significant drawbacks: physicochemical methods such as iron-carbon microelectrolysis suffer from problems like packing material caking, decreased efficiency, and the need for a strong acidic operating environment; Fenton oxidation relies on large amounts of expensive reagents, produces toxic byproducts, and incurs high sludge disposal costs; membrane technology, while effective in separation, requires huge investments, is prone to fouling and clogging, and has a short lifespan; traditional biochemical methods suffer from poor microbial tolerance to high concentrations of toxic substances, resulting in weak system shock resistance, poor nitrogen and phosphorus removal, and unstable operation. Overall, these methods are often costly, complex to operate, and may carry the risk of secondary pollution, making it difficult to balance economic efficiency, high efficiency, and long-term operational reliability. Summary of the Invention

[0006] The purpose of this invention is to solve the problems in the prior art by proposing a photoelectric field enhanced iron-carbon based catalytic oxidation wastewater treatment method and apparatus.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A photoelectric field-enhanced method for treating wastewater using iron-carbon-based catalytic oxidation includes the following steps: S1: Wastewater enters the water distribution chamber, where the initial pH value is adjusted according to the water quality. S2: The adjusted wastewater enters the catalytic oxidation chamber and is oxygenated, and is purified under the synergistic effect of iron-carbon materials and ultraviolet light; S2 includes: wastewater enters the catalytic oxidation chamber evenly through a water distribution mechanism, and oxygen is introduced into the wastewater through a micro-nano aerator. The ultraviolet light generated by the ultraviolet light generator works together with the spherical iron-carbon-based catalytic material to generate and enhance the generation of hydroxyl radicals. S3: Wastewater enters the electric field chamber, where the electric field further generates strong oxidizing substances that directly oxidize pollutants and promote the conversion and removal of nitrogen through electrochemical action. The electric field also enhances the cycling of iron ions and the precipitation reaction of phosphorus. S4: The effluent after the reaction treatment enters the solid-liquid separator for mud-water separation.

[0008] Furthermore, S4 includes: S41: Add flocculant and stir to allow it to fully react with residual metal ions and suspended solids in the wastewater to form dense flocs; S42: Wastewater is separated from flocs by a separation mechanism, and large flocs settle under gravity. S43: The supernatant undergoes deep sedimentation through inclined tube packing to further remove fine suspended solids, and the clarified effluent is discharged through the effluent weir.

[0009] The present invention also provides a photoelectric field enhanced iron-carbon based catalytic oxidation wastewater treatment device, including a reactor and a solid-liquid separator; The reactor includes a catalytic oxidation chamber and an electric field chamber arranged along the wastewater flow direction. The catalytic oxidation chamber is equipped with catalytic material and a first ultraviolet light generator. A water distribution mechanism is provided at the bottom of the catalytic oxidation chamber, and an aeration mechanism is provided above the water distribution mechanism. The aeration mechanism is used to inject oxygen into the wastewater and drive the wastewater and catalytic material to circulate around the first ultraviolet light generator. An electrode plate and a second ultraviolet light generator are provided inside the electric field chamber. The solid-liquid separator is connected to the reactor and is used for mud-water separation.

[0010] Furthermore, the water distribution mechanism includes a sieve plate, which is located at the bottom of the catalytic oxidation chamber. The sieve plate has multiple sieve holes, which are arranged in a ring shape. The aeration mechanism includes an annular tube, which is located on top of the screen plate. Multiple nozzles are spaced apart on the inner side of the annular tube, and each screen hole is located on the inner side of the annular tube so that each nozzle is horizontally facing upwards from each screen hole.

[0011] Furthermore, the first ultraviolet light generator is positioned above the aeration mechanism and in the middle of the catalytic oxidation chamber, and the catalytic material is distributed around the first ultraviolet light generator. The first ultraviolet light generator includes two lamps arranged in a spiral shape and staggered, with each sieve hole located below the two lamps; The catalyst is an iron-carbon based catalyst and is in the form of spherical particles.

[0012] Furthermore, a water distribution chamber is located at the bottom of the catalytic oxidation chamber, and the interior of the water distribution chamber is equipped with a water inlet pipe and a pH adjustment mechanism.

[0013] Furthermore, the electric field chamber also includes a DC pulse power supply for supplying power to the electrode plates; The electrode plate includes multiple anodes and cathodes arranged in parallel and cross directions, and a second ultraviolet light generator is disposed above each anode and each cathode; A connecting pipe is installed between the electric field chamber and the solid-liquid separator.

[0014] Furthermore, the solid-liquid separator includes an outer chamber and an inner chamber, with the inner chamber connected to the reactor; The interior of the chamber is equipped with stirring blades to agitate and rotate the wastewater; The bottom of the inner chamber is provided with a sedimentation chamber, and a separation mechanism is provided between the inner chamber and the sedimentation chamber. The separation mechanism includes multiple filter plates arranged in a ring. Each filter plate is inclined downward along the direction of wastewater rotation so that the rotating wastewater contacts the lower surface of each filter plate.

[0015] Furthermore, the inner chamber is connected to the outer chamber at the top, and the outer chamber is equipped with inclined tube packing. A water outlet weir is provided on the top side of the solid-liquid separator, and the water outlet weir is connected to the outer chamber.

[0016] The beneficial effects of this invention are as follows: In this invention, the photoelectric field-enhanced iron-carbon-based catalytic oxidation wastewater treatment method achieves highly efficient removal of COD, ammonia nitrogen, and total phosphorus from water through the synergistic effects of the redox and adsorption of iron-carbon-based catalytic materials, photocatalysis under ultraviolet light, and electrochemical reactions under an electric field. By coupling multiple mechanisms of "catalytic oxidation + adsorption flocculation + electrochemical reaction," a highly efficient wastewater treatment system with multi-mechanism synergy is constructed, capable of simultaneously and deeply removing COD, ammonia nitrogen, and total phosphorus. This significantly improves the treatment efficiency of recalcitrant toxic wastewater and, by generating strong oxidizing free radicals in situ, significantly reduces the dependence on chemical agents and operating costs of traditional Fenton processes, while avoiding problems such as packing caking, large sludge production, and secondary pollution.

[0017] The photoelectric field enhanced iron-carbon based catalytic oxidation wastewater treatment device promotes the catalytic material to circulate with the wastewater through an aeration mechanism. On the one hand, it improves the contact adsorption effect between the wastewater and the catalytic material. On the other hand, the wastewater and the catalytic material circulate together around the first ultraviolet light generator, which facilitates the synergistic treatment of wastewater by the ultraviolet light emitted by the first ultraviolet light generator and the catalytic material, thereby improving the synergistic effect of ultraviolet light and catalytic material in wastewater treatment. Attached Figure Description

[0018] Figure 1 This is a three-dimensional structural schematic diagram of a photoelectric field-enhanced iron-carbon-based catalytic oxidation wastewater treatment device proposed in this invention; Figure 2 This is a cross-sectional structural schematic diagram of a photoelectric field-enhanced iron-carbon-based catalytic oxidation wastewater treatment device proposed in this invention; Figure 3 This is a three-dimensional structural diagram of the catalytic oxidation chamber of a photoelectric field-enhanced iron-carbon-based catalytic oxidation wastewater treatment device proposed in this invention; Figure 4 This is a three-dimensional structural diagram of the separation mechanism of a photoelectric field-enhanced iron-carbon-based catalytic oxidation wastewater treatment device proposed in this invention.

[0019] In the diagram: 1 Water distribution chamber, 101 Water inlet pipe, 2 Aeration mechanism, 201 Air inlet pipe, 202 Annular pipe, 2021 Nozzle, 3 Catalytic oxidation chamber, 301 Catalytic material, 302 Water distribution mechanism, 3021 Screen, 4 First ultraviolet light generator, 401 Lamp tube, 5 Electric field chamber, 501 Electrode plate, 6 Second ultraviolet light generator, 7 Connecting pipe, 8 Solid-liquid separator, 801 Outer shell, 802 Inner shell, 9 Drive motor, 10 Outlet weir, 11 Inclined tube packing, 12 Stirring blade, 13 Separation mechanism, 1301 Filter plate, 14 Sludge discharge pipe. Detailed Implementation

[0020] The technical solution of this patent will be further described in detail below with reference to specific embodiments.

[0021] The embodiments of this patent are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this patent, and should not be construed as limiting this patent.

[0022] In the description of this patent, it should be understood that the terms “center,” “upper,” “lower,” “front,” “back,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” and “outer,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this patent and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this patent.

[0023] In the description of this patent, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection or setting, a detachable connection or setting, or an integral connection or setting. Those skilled in the art can understand the specific meaning of the above terms in this patent according to the specific circumstances.

[0024] Reference Figure 1-4 A photoelectric field-enhanced iron-carbon-based catalytic oxidation wastewater treatment method is applied to wastewater treatment to ensure the economy, efficiency and long-term reliability of wastewater treatment.

[0025] The photoelectric field-enhanced iron-carbon-based catalytic oxidation wastewater treatment method includes the following steps: S1: Wastewater first enters the water distribution chamber 1 at the bottom of the photoelectrophotovoltaic reactor through the inlet pipe 101. The initial pH value is adjusted according to the water quality. Then, the wastewater is distributed through the sieve plate of the water distribution structure 302, so that the wastewater enters the catalytic oxidation chamber 3 of the photoelectrophotovoltaic reactor evenly.

[0026] S2: When wastewater enters the catalytic oxidation chamber 3 through the sieve 3021, it is oxygenated by the aeration mechanism 2. At the same time, the wastewater and the catalytic material 301 are driven to circulate around the first ultraviolet light generator 4. The photons generated by the first ultraviolet light generator 4 can break the covalent bonds of oxygen molecules, causing free oxygen atoms to generate O3. Under the iron circulation effect of the catalytic material 301, the activation energy of catalytic oxidation of pollutants is reduced, and O3 is converted into hydroxyl radicals ·OH, which have stronger oxidizing power, higher reactivity, non-selectivity, and stronger oxidizing power, thus significantly improving the pollutant removal efficiency.

[0027] Among them, the iron-carbon-based heterogeneous catalytic material has a huge specific surface area and strong adsorption capacity, non-selectively adsorbing various pollutants in wastewater. This causes pollutants in the water to first transfer to the surface of the catalytic material, exhibiting localized high-concentration enrichment, thus increasing the probability and efficiency of oxidation and decomposition. An iron-carbon micro-electrolysis cell effect occurs on the material surface, generating ·OH. Simultaneously, under ultraviolet light conditions, ultraviolet light activates photogenerated carriers, and UV irradiation promotes the generation of Fe²⁺ by iron-carbon micro-electrolysis. + Rapid oxidation to Fe³ + At the same time, Fe³ + It can also be reduced to Fe² by photogenerated electrons. + To form highly efficient Fe² + / Fe³ + The cycle continuously generates highly oxidizing ·OH. The energy of UV radiation can excite electron transitions on the surface of iron-carbon based materials, lowering the reaction activation energy, increasing the electron transfer rate between iron and carbon, and enhancing the redox degradation ability of pollutants. Some pollutants can be directly photolyzed by UV radiation, while the Fe³⁺ produced by the iron-carbon system... + Intermediate products work synergistically with UV to further mineralize recalcitrant organic matter into CO2 and H2O, thereby improving the overall removal rate.

[0028] S3: Wastewater enters electric field chamber 5 under the influence of upflow. Due to the presence of Fe in the electric field... 2+ ←→Fe 3+ Cyclic activity promotes electrode reactions through electron transfer mediators and active species (such as H2O2 and S2O8). 2- The dual activation effect of O3, Fe3O4, C, etc. enhances electric field oxidation and catalytic oxidation respectively, which efficiently degrades pollutants and significantly improves the synergistic degradation efficiency of pollutants compared with traditional electrocatalytic oxidation.

[0029] In this process, the strong oxidizing substances (such as ·OH, Cl2) generated at the anode of the electric field under the action of a DC pulsed electric field directly oxidize ammonia nitrogen (NH3-N) and organic nitrogen into nitrogen gas (N2), or first convert them into nitrite (NO2). - ), which is further oxidized to nitrate (NO3). - This process achieves the removal or transformation of ammonia nitrogen. Electrochemical reduction of NO3 occurs on the cathode surface. - and NO2 - It is reduced to N2, ultimately achieving "electrochemical denitrification".

[0030] Total phosphorus (TP) and dissolved phosphorus (such as PO4³) in wastewater - Then the newly generated Fe² released in the system + Fe³ + Metal ions, and PO4³⁺ in water -The reaction combines to form precipitates with extremely low solubility, such as Fe3(PO4)2 and FePO4, thereby removing total phosphorus. The electric field also accelerates this reaction. At the anode, a strong oxidizing agent can decompose organic phosphorus (such as phospholipids and organic phosphates), converting them into soluble inorganic phosphorus (PO4³⁺). - Then, it is removed through a chemical precipitation reaction. The cathode reaction consumes H₂. + Or generate OH - This increases the pH value of the water, promoting the growth of Fe³⁺. + With PO4³ - The precipitation reaction indirectly assists in the removal of phosphorus.

[0031] The electric field-enhanced iron-carbon-based material system accelerates the conduction and migration of electrons, which significantly increases the yield of ·OH and the probability of contact with pollutants. At the same time, the reaction rate and the volume of the reaction site are also significantly increased. This allows the recalcitrant organic matter in wastewater to be efficiently and rapidly decomposed into harmless small molecules (CO2 and H2O) and shortens the reaction time.

[0032] S3: After the reactor reaction, the effluent enters the solid-liquid separator 8. The wastewater enters the inner chamber 802 through the connecting pipe 7. The stirring blades 12 rotate inside the inner chamber 802, causing the wastewater in the inner chamber 802 to react with the added flocculant to form coarse and dense alum flocs, mainly composed of residual Fe. 3+ The reaction produces Fe(OH)3 and iron hydroxyl complexes, which are formed through bridging.

[0033] In this embodiment, an iron-carbon based heterogeneous catalytic material (Fe / C composite material, Fe3O4-C with supported metal, etc.) is added to or filled into the reaction system to utilize its "micro-cell effect" (iron as the anode and carbon as the cathode) to generate Fe²⁺. + The material contains ·OH groups, and the active sites on the surface of the material can adsorb pollutants, thereby removing organic matter, nitrogen, and phosphorus from wastewater.

[0034] Introducing ultraviolet (UV) light into the system further enhances the process. By introducing 180nm UV light, the catalyst on the surface of the iron-carbon material (TiO2 / Fe-C composite material) is activated to generate more ·OH, and Fe²⁺ is promoted to produce more ·OH. + To Fe³ + Transformation, enhancing the oxidative decomposition of COD.

[0035] In some embodiments, a cathode and anode (titanium-based RuIr anode, stainless steel or Ti cathode) are inserted into the system, and a low-voltage DC electric field with a current intensity of 10 mA / cm is applied. 2 -500mA / cm 2To create a main electric field, this invention also incorporates iron-carbon based materials between the electrodes, thus generating a new local micro-electric field within the main electric field. This change significantly improves the reaction interface of the electrodes. Polarization charge accumulates at the interface between the iron-carbon based catalyst and the water, forming a local micro-electric field near the interface. This micro-electric field accelerates the adsorption and reaction of surrounding ions or pollutants, thereby reducing the energy consumption of the main electric field. Under the drive of the external electric field, charged ions in the system accumulate within the pores of the material, forming a concentration gradient and charge-rich region, which in turn generates a local micro-electric field. The formation of this micro-electric field increases the electrode area and electric field strength, allowing for an increase in the spacing between the main electric field electrodes and significantly saving electrode material.

[0036] Under the influence of an electric field, H2O or OH on the anode surface... - It loses electrons and directly generates ·OH, the reaction formula is: H2O-e - →·OH+H + The ·OH generated in this way is highly reactive and directly adsorbed onto the electrode surface, which can quickly oxidize pollutants in wastewater.

[0037] Under the influence of an electric field (including a main electric field and a micro electric field), electrons are enriched on the cathode surface. O2 gains electrons and undergoes a reduction reaction to generate H2O2. H2O2 then reacts under the electric field or with the catalyst Fe²⁺. + Under the influence of the electric field, it decomposes into ·OH, forming a "field-enhanced Fenton reaction": O2 + 2H2O + 2e - →H₂O₂ + 2OH⁻ - (Cathode reduction to produce H2O2) H2O2 + Fe² + →·OH+OH - +Fe³ + (H2O2 decomposes to produce ·OH) Under the synergistic effect of light and electric fields, the catalytic material (TiO2 / Fe-C composite material) and transition metal oxides (MnO2, Co3O4) in the system are activated, and the electron-hole separation efficiency is significantly increased. After photoelectric synergistic excitation, the catalytic material generates holes (h... + They migrate to the surface and oxidize H2O or OH. - The formation of ·OH groups, coupled with the suppression of electron-hole recombination by the electric field, prolongs the existence time of ·OH groups and significantly increases their formation amount. Ultimately, this results in a significant increase in the quantity and existence time of highly active ·OH groups in the system, thereby significantly enhancing the oxidative decomposition capacity of pollutants in wastewater.

[0038] In some embodiments, an enterprise's electroplating wastewater has a COD concentration of 3139 mg / L, an NH3-N concentration of 359 mg / L, a TP concentration of 757 mg / L, a TN concentration of 616 mg / L, and a pH of 1.0. The treatment effect of the method of this invention on this wastewater is as follows: Take 1000ml of electroplating wastewater, adjust the pH to 3-4, add 300ml of spherical iron-carbon based catalyst material with a diameter of 5-8mm, add a RuIrTi-Ti electrode with a plate spacing of 20mm, and control the current density to 5.2mA / cm². 2 An electric field was constructed by connecting a pulsed DC power supply. After continuous reaction for 2 hours, a sample was taken and NaOH was added to adjust the pH to neutral. After natural precipitation and solid-liquid separation, the supernatant was taken to detect the concentrations of COD, NH3-N, TP, and TN. The COD concentration decreased to 734.5 mg / L, with a COD removal rate of 76.6%; the NH3-N concentration decreased to 45.6 mg / L, with an NH3-N removal rate of 87.3%; the TP concentration decreased to 0.76 mg / L, with a TP removal rate of 99.9%; and the TN concentration decreased to 123.8 mg / L, with a TN removal rate of 79.9%.

[0039] In some embodiments, the pharmaceutical wastewater generated by a certain enterprise during normal production mainly originates from equipment cleaning and floor wastewater during the production process. The main pollutants in the wastewater are organic matter, nitrogen and phosphorus, and suspended solids. However, due to the use of organic solvents such as chloroform, petroleum ether, acetonitrile, acetone, and dichloromethane in the production process, which are generally toxic to microorganisms, the wastewater has a COD concentration of 1383 mg / L, an NH3-N concentration of 451 mg / L, a TP concentration of 68.6 mg / L, and a pH of 9.85. The treatment effect of the method of this invention on this wastewater is as follows: 1L of pharmaceutical wastewater was taken for experiments #1 and #2, respectively. First, 4ml / L of PAC and 3ml / L of PAM were added to the raw water, and the mixture was stirred thoroughly for coagulation and sedimentation. 800ml of the coagulated and precipitated effluent was taken from each experiment, and 300ml of spherical iron-carbon based catalyst material (5-8mm in diameter) was added. A RuIrTi-Ti electrode with a 20mm spacing was then added, and the current density was 7.8mA / cm². 2 After continuous reaction for 1 hour with DC power, a sample was taken and PAM was added for coagulation and precipitation. After precipitation, the supernatant was taken to detect the concentrations of COD, NH3-N, and TP. The experimental results are shown in Table 1.

[0040] Table 1

[0041] As can be seen from Table 1, the method of the present invention has a good removal effect on toxic, recalcitrant, and unsuitable for biochemical treatment of industrial wastewater (such as electroplating wastewater and pharmaceutical wastewater).

[0042] In some embodiments, the COD removal efficiency can reach 70%-95%, and it is especially suitable for recalcitrant organic wastewater (such as electroplating and pharmaceutical wastewater), and can oxidize long-chain organic matter into small molecule acids or CO2 and H2O.

[0043] Among them, the ·OH generated by the iron-carbon microcell, the photogenerated carriers activated by ultraviolet light, and the oxide species (·OH, O2) at the anode of the electric field - These substances work together to attack the chemical bonds of organic pollutants (such as C, C, and CN bonds), breaking them down into harmless small molecules. Carbon materials (such as activated carbon and graphene) have a high specific surface area, which adsorbs some organic matter, providing a "local high-concentration environment" for the oxidation reaction and improving the oxidation efficiency.

[0044] In some embodiments, the ammonia nitrogen removal effect is achieved through catalytic oxidation (·OH, ClO). - "+ electric field desorption" removes 80%-98% of the material, avoiding the "low-temperature failure" problem of traditional nitrification and denitrification.

[0045] Among them, ·OH, ClO - (Cl under electric field) - (Oxidation to generate) NH4 + Gradually oxidize to N2 (main path) to avoid generating NO2. - NO3 - Secondary pollutants; OH generated at the cathode - Increase local pH and promote NH4 + It is converted into NH3 and then removed by electric field migration.

[0046] In some embodiments, the total phosphorus removal efficiency reaches over 90%, primarily due to the release of Fe²⁺ from iron-carbon materials. + / Fe³ + With PO4³ - Fe3(PO4)2 and FePO4 precipitates are formed, and phosphorus is adsorbed on the material surface. The electric field further promotes the aggregation of the precipitates.

[0047] Among them, Fe² released by iron-carbon materials + (Oxidized to Fe³) + ) and PO4³ in water - The reaction produces a sparingly soluble ferric phosphate precipitate; Hydroxyl groups (-OH) on the surface of iron-carbon materials and PO4³ - Coordinate bonds are formed, and the electric field promotes the formation of PO4³ - It migrates towards the positive electrode, enhancing adsorption.

[0048] This invention also provides a photoelectric field-enhanced iron-carbon-based catalytic oxidation wastewater treatment device, including a reactor and a solid-liquid separator 8; The reactor includes a water distribution chamber 1, a catalytic oxidation chamber 3, and an electric field chamber 5 arranged along the wastewater flow direction.

[0049] The water distribution chamber 1 is located at the bottom of the catalytic oxidation chamber 3. Inside the water distribution chamber 1 is an inlet pipe 101 and a pH adjustment mechanism. The inlet pipe 101 has multiple outlets to ensure that wastewater enters the water distribution chamber 1 evenly. The pH adjustment mechanism includes a reagent addition port, located on one side of the water distribution chamber 1, for convenient addition of pH adjustment reagents into the chamber.

[0050] In some embodiments, a pH measuring instrument is provided inside the water distribution chamber 1 to measure the pH value of the wastewater inside the water distribution chamber 1.

[0051] A water distribution mechanism 302 is provided at the bottom of the catalytic oxidation chamber 3, and an aeration mechanism 2 is provided above the water distribution mechanism 302.

[0052] In some embodiments, the water distribution mechanism 302 includes a sieve plate disposed at the bottom of the catalytic oxidation chamber 3. The sieve plate is provided with a plurality of sieve holes 3021, and each sieve hole 3021 is arranged in a ring so that the wastewater inside the water distribution chamber 1 enters the interior of the catalytic oxidation chamber 3 evenly through each sieve hole.

[0053] In some embodiments, the aeration mechanism 2 includes an annular tube 202 disposed on the top of the sieve plate. A plurality of nozzles 2021 are spaced apart on the inner side of the annular tube 202, and each sieve hole is located on the inner side of the annular tube 202, so that each nozzle 2021 is horizontally oriented above each sieve hole 3021.

[0054] When wastewater enters the catalytic oxidation chamber 3 evenly through each sieve hole 3021, each nozzle 2021 sprays oxygen towards the center position. That is, while injecting oxygen into the wastewater entering the catalytic oxidation chamber 3, it pushes the wastewater to flow towards the center position. As a result, the wastewater at the bottom of the catalytic oxidation chamber 3 flows from the outside to the center position and flows upward in the middle of the catalytic oxidation chamber 3, while the wastewater on the outside falls to the position of the annular pipe 202 and returns to the center position of the catalytic oxidation chamber 3 through the oxygen sprayed by the nozzle 2021, so that the wastewater forms a cycle inside the catalytic oxidation chamber 3.

[0055] In some embodiments, the annular pipe 202 is connected to an external fan to inject air or oxygen into the interior of the annular pipe 202.

[0056] The catalytic oxidation chamber 3 is equipped with a catalytic material 301 and a first ultraviolet light generator 4.

[0057] In some embodiments, the first ultraviolet light generator 4 is disposed above the aeration mechanism 2 and located in the middle of the catalytic oxidation chamber 3, and the catalytic material 301 is distributed around the first ultraviolet light generator 4. When the aeration mechanism 2 pushes the wastewater to flow towards the center of the catalytic oxidation chamber 3, it also pushes the catalytic material 301 to flow accordingly. On the one hand, this improves the contact adsorption effect between the wastewater and the catalytic material 301. On the other hand, since the first ultraviolet light generator 4 is located in the middle of the catalytic oxidation chamber 3, the wastewater and the catalytic material 301 will circulate around the first ultraviolet light generator 4 together, thereby facilitating the synergistic treatment of the wastewater by the ultraviolet light emitted by the first ultraviolet light generator 4 and the catalytic material 301, thus improving the wastewater treatment effect.

[0058] The photons generated by the first ultraviolet light generator 4 can break the covalent bonds of oxygen molecules, causing free oxygen atoms to generate O3. Under the iron cycling action of the catalytic material 301, the activation energy of catalytic oxidation of pollutants is reduced, and O3 is converted into hydroxyl radicals ·OH, which have stronger oxidizing power, higher reactivity, non-selectivity, and stronger oxidizing power, thus significantly improving the pollutant removal efficiency.

[0059] In some embodiments, the first ultraviolet light generator 4 includes two lamps 401 arranged in a spiral shape and staggered, with each sieve hole located below the two lamps 401. The spiral shape of the lamps 401 can enhance the ultraviolet light irradiation effect, and this shape of the lamps 401 can be matched with the circulation path of wastewater and catalyst material 301. When wastewater and catalyst material 301 flow upward from the middle of the catalytic oxidation chamber 3, they will pass through the spiral lamps 401. The spiral shape of the lamps 401 can ensure that wastewater and catalyst material 301 are always fully irradiated by ultraviolet light during the upward process, thereby ensuring the synergistic treatment effect of ultraviolet light and catalyst material 301 on wastewater.

[0060] In some embodiments, the catalyst material 301 is an iron-carbon based catalyst material and is in the form of spherical particles. The spherical particles of the catalyst material 301 have a large surface area ratio, which facilitates its adsorption of pollutants inside the wastewater. At the same time, the spherical catalyst material 301 can easily circulate with the wastewater inside the catalytic oxidation chamber 3, avoiding damage to the internal components of the catalytic oxidation chamber 3.

[0061] The electric field chamber 5 is equipped with an electrode plate 501 and a second ultraviolet light generator 6.

[0062] In some embodiments, the electric field chamber 5 further includes a DC pulse power supply for supplying power to the electrode plate 501.

[0063] In some embodiments, the electrode plate 501 includes a plurality of parallel and intersecting anodes and cathodes arranged vertically, and the second ultraviolet light generator 6 is disposed above each anode and cathode and arranged horizontally to ensure that the ultraviolet light is not blocked by the electrode plate 501.

[0064] Because Fe exists in the electric field 2+ ←→Fe 3+ Cyclic activity promotes electrode reactions through electron transfer mediators and active species (such as H2O2 and S2O8). 2- The dual activation effect of O3, Fe3O4, C, etc. enhances electric field oxidation and catalytic oxidation respectively, which efficiently degrades pollutants and significantly improves the synergistic degradation efficiency of pollutants compared with traditional electrocatalytic oxidation.

[0065] The solid-liquid separator 8 includes an outer chamber 801 and an inner chamber 802, with the inner chamber 802 connected to the electric field chamber 5 via a connecting pipe 7. Wastewater from the reaction can enter the inner chamber 802 through the connecting pipe 7 for sedimentation.

[0066] In some embodiments, the interior of the inner chamber 802 is provided with a stirring blade 12, and a drive motor 9 is provided at the top of the inner chamber 802. The output shaft of the drive motor 9 is connected to the stirring blade 12 to drive the stirring blade 12 to rotate, thereby causing the wastewater to be stirred and rotated.

[0067] The top of the inner chamber 802 is equipped with a chemical inlet, which allows flocculant to be added into the inner chamber 802. After the flocculant is added, the stirring blade 12 can be rotated by the drive motor 9, thereby mixing the wastewater with the flocculant and producing flocculent sediment.

[0068] In some embodiments, a sedimentation chamber is provided at the bottom of the inner chamber 802, and a separation mechanism 13 is provided between the inner chamber 802 and the sedimentation chamber. The separation mechanism 13 includes a plurality of filter plates 1301 arranged in a ring, and each filter plate 1301 is inclined downward along the direction of wastewater rotation.

[0069] Wastewater rotates and flows under the stirring of the agitator blades 12. Since each filter plate 1301 is inclined downward along the direction of wastewater rotation, as the wastewater rotates with the stirring of the agitator blades 12, the flocculent precipitate will spiral down. The rotating wastewater carries the spirally descending flocculent precipitate to contact the lower surface of each filter plate 1301. The flocculent precipitate is intercepted by the inclined filter plates 1301 and thus enters the sedimentation chamber at the bottom of the inner chamber 802, improving the sedimentation effect of the flocculent precipitate.

[0070] In some embodiments, a drain outlet is provided at the bottom of the sedimentation chamber to facilitate the discharge of settled sludge.

[0071] In some embodiments, the upper part of the inner chamber 802 is connected to the outer chamber 801, the outer chamber 801 is provided with inclined tube packing 11, and the top of one side of the solid-liquid separator 8 is provided with a water outlet weir 10, which is connected to the outer chamber 801.

[0072] The supernatant in the inner chamber 802 enters the outer chamber 801 and passes through the inclined tube packing 11. The inclined tubes utilize the "shallow sedimentation principle," which shortens the particle settling distance, increases the settling velocity, increases the sedimentation area, improves the water flow state, avoids water flow turbulence, and improves sedimentation efficiency. Finally, the effluent is discharged from the effluent weir 10 at the top of the solid-liquid separator 8, completing the wastewater purification process.

[0073] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for treating wastewater by photoelectric field-enhanced iron-carbon-based catalytic oxidation, characterized in that, Includes the following steps: S1: Wastewater enters the water distribution chamber, where the initial pH value is adjusted according to the water quality. S2: The adjusted wastewater enters the catalytic oxidation chamber and is oxygenated, and is purified under the synergistic effect of iron-carbon materials and ultraviolet light; S3: Wastewater enters the electric field chamber, where the electric field further generates strong oxidizing substances that directly oxidize pollutants and promote the conversion and removal of nitrogen through electrochemical action. The electric field also enhances the cycling of iron ions and the precipitation reaction of phosphorus. S4: The effluent after the reaction treatment enters the solid-liquid separator for mud-water separation.

2. The photoelectric field-enhanced iron-carbon-based catalytic oxidation wastewater treatment method according to claim 1, characterized in that: S2 includes: Wastewater enters the catalytic oxidation chamber evenly through a water distribution mechanism, and oxygen is introduced into the wastewater through a micro-nano aerator. The ultraviolet light generated by the ultraviolet light generator works together with the spherical iron-carbon-based catalytic material to generate and enhance the formation of hydroxyl radicals.

3. The photoelectric field-enhanced iron-carbon-based catalytic oxidation wastewater treatment method according to claim 1, characterized in that: S4 includes: S41: Add flocculant and stir to allow it to fully react with residual metal ions and suspended solids in the wastewater to form dense flocs; S42: Wastewater is separated from flocs by a separation mechanism, and large flocs settle under gravity. S43: The supernatant undergoes deep sedimentation through inclined tube packing to further remove fine suspended solids, and the clarified effluent is discharged through the effluent weir.

4. A photoelectric field-enhanced iron-carbon-based catalytic oxidation wastewater treatment device, characterized in that: Includes reactors and solid-liquid separators (8); The reactor includes a catalytic oxidation chamber (3) and an electric field chamber (5) arranged along the wastewater flow direction. The catalytic oxidation chamber (3) is equipped with a catalytic material (301) and a first ultraviolet light generator (4). The bottom of the catalytic oxidation chamber (3) is equipped with a water distribution mechanism (302), and an aeration mechanism (2) is provided above the water distribution mechanism. The aeration mechanism (2) is used to inject oxygen into the wastewater and drive the wastewater and the catalytic material (301) to circulate around the first ultraviolet light generator (4). The electric field chamber (5) is equipped with an electrode plate (501) and a second ultraviolet light generator (6). The solid-liquid separator (8) is connected to the reactor and is used for mud-water separation.

5. The photoelectric field-enhanced iron-carbon based catalytic oxidation wastewater treatment device according to claim 4, characterized in that: The water distribution mechanism (302) includes a sieve plate, which is disposed at the bottom of the catalytic oxidation chamber (3). The sieve plate is provided with a plurality of sieve holes (3021), and each of the sieve holes (3021) is arranged in a ring. The aeration mechanism (2) includes an annular tube (202) disposed on the top of the sieve plate. Multiple nozzles (2021) are spaced apart on the inner side of the annular tube (202). Each sieve hole (3021) is located on the inner side of the annular tube (202) so that each nozzle (2021) is horizontally facing the top of each sieve hole.

6. The photoelectric field-enhanced iron-carbon-based catalytic oxidation wastewater treatment device according to claim 5, characterized in that: The first ultraviolet light generator (4) is disposed above the aeration mechanism (2) and in the middle of the catalytic oxidation chamber (3), and the catalytic material (301) is distributed around the first ultraviolet light generator (4); The first ultraviolet light generator (4) includes two lamp tubes (401), which are spirally arranged and staggered, and each of the sieve holes (3021) is located below the two lamp tubes (401); The catalyst material (301) is an iron-carbon based catalyst material and is in the form of spherical particles.

7. The photoelectric field-enhanced iron-carbon-based catalytic oxidation wastewater treatment device according to claim 4, characterized in that: The bottom of the catalytic oxidation chamber (3) is provided with a water distribution chamber (1), and the water distribution chamber (1) is provided with an inlet pipe (101) and a pH adjustment mechanism.

8. The photoelectric field-enhanced iron-carbon-based catalytic oxidation wastewater treatment device according to claim 4, characterized in that: The electric field chamber (5) also includes a DC pulse power supply for supplying power to the electrode plate (501); The electrode plate (501) includes a plurality of parallel and cross-arranged anodes and cathodes, and the second ultraviolet light generator (6) is disposed above each of the anodes and cathodes; A connecting pipe (7) is provided between the electric field chamber (5) and the solid-liquid separator (8).

9. The photoelectric field-enhanced iron-carbon based catalytic oxidation wastewater treatment device according to claim 4, characterized in that: The solid-liquid separator (8) includes an outer chamber (801) and an inner chamber (802), the inner chamber (802) being connected to the reactor; The inner chamber (802) is equipped with stirring blades (12) to stir and rotate the wastewater; The bottom of the inner chamber (802) is provided with a sedimentation chamber, and a separation mechanism (13) is provided between the inner chamber (802) and the sedimentation chamber. The separation mechanism (13) includes a plurality of filter plates (1301) arranged in a ring. Each filter plate (1301) is inclined downward along the direction of wastewater rotation so that the rotating wastewater contacts the lower surface of each filter plate (1301).

10. The photoelectric field-enhanced iron-carbon-based catalytic oxidation wastewater treatment device according to claim 9, characterized in that: The inner chamber (802) is connected to the outer chamber (801) above. The outer chamber (801) is provided with inclined tube packing (11). The solid-liquid separator (8) is provided with a water outlet weir (10) on one side top. The water outlet weir (10) is connected to the outer chamber (801).

Images