Fenton oxidation reaction device

Abstract

The utility model provides an efficient Fenton oxidation reaction device. The efficient Fenton oxidation reaction device comprises a pretreatment tank, a gradient iron-carbon reaction tank, a dual-Fenton oxidation tank and a TMF deep filtering unit which are sequentially arranged along the water flow direction. The pretreatment pool integrates a cyclone separation and ozone micro-nano bubble coupling technology, and the subsequent load is reduced through the dual effects of physical cutting and pre-oxidation. The iron-carbon reaction tank is of a layered filler structure, upper-layer scrap iron is subjected to microelectrolysis, middle-layer activated carbon-iron powder composite filler enhances electron transfer, lower-layer nanoscale zero-valent iron realizes deep reduction, and the double-Fenton oxidation tank is provided with a coil pipe type temperature control module to maintain the reaction temperature. The TMF unit adopts a polyethersulfone catalytic composite membrane and is matched with a gas-liquid pulse backwashing system to realize filtration-catalysis cooperation. The system effectively solves the complex wastewater treatment problem through stage treatment and intelligent control, and has the technical advantages of high treatment efficiency, stable operation, high pollution resistance and the like.

Description

Technical Field

[0001] This utility model relates to the field of wastewater treatment technology, specifically to a Fenton oxidation reaction device. Background Technology

[0002] Fenton oxidation is a type of advanced oxidation technology that is widely used in wastewater treatment. Under acidic conditions, ferrous sulfate and hydrogen peroxide are added to react and generate hydroxyl radicals. The strong oxidizing properties of the hydroxyl radicals then lead to the oxidative degradation of substances such as alkanes, aromatics, alcohols, and phenols.

[0003] The utility model patent with publication number CN222476320U provides a Fenton oxidation reaction device, which uses an iron-carbon reaction tank filled with iron-carbon packing to replace ferrous sulfate. It decomposes some organic matter by reacting iron and carbon with substances in wastewater through iron-carbon oxidation-reduction. The ferrous ions generated after the reaction of sulfuric acid with iron ions are used to provide ferrous ions for the subsequent Fenton reaction, thereby reducing the wastewater purification cost for enterprises. However, the wastewater after Fenton oxidation in this technology still contains micron-sized suspended solids and / or some non-oxidation-reduction degradation impurities, which need to be further separated. Utility Model Content

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a Fenton oxidation reaction device to solve the technical problem that the prior art is not perfect in purifying impurities that are not degraded by Fenton.

[0005] To achieve the above objectives, the technical solution provided by this utility model is as follows:

[0006] A Fenton reaction device includes a pretreatment tank, an iron-carbon reaction tank, a first Fenton oxidation tank, a second Fenton oxidation tank, and a TMF deep filtration unit connected sequentially along the water flow direction.

[0007] The bottom of the pretreatment tank is equipped with a cyclone separator and a nanobubble generator;

[0008] The iron-carbon reaction tank is filled with a gradient iron-carbon packing material in layers, including an upper layer of large-pore waste iron filings, a middle layer of activated carbon-iron powder composite packing material, and a lower layer of nano-zero-valent iron particles.

[0009] Both the first and second Fenton oxidation tanks are equipped with a stirrer and a coil-type temperature control module.

[0010] The TMF deep filtration unit includes vertically staggered catalytic composite membrane modules, a gas-liquid pulse backwashing system, and a membrane fouling early warning module.

[0011] Furthermore, the catalytic composite membrane module is a polyethersulfone substrate with a catalytic layer loaded on its surface, and the membrane pore size is 0.005~0.05μm.

[0012] Furthermore, the gas-liquid pulse backwashing system includes a high-pressure air tank, a chemical storage tank, and a pulse controller. The high-pressure air tank is connected to an air nozzle, and the chemical storage tank includes an alkali storage tank and an acid storage tank. The alkali storage tank and the acid storage tank are each connected to the air nozzle through a set of dosing pumps and valves via pipelines. The air nozzle is adjusted by the pulse controller to alternate between air sweeping, acid washing, and alkali washing modes.

[0013] Furthermore, the membrane fouling early warning module includes a transmembrane pressure differential sensor and an online turbidity monitor. When the transmembrane pressure differential exceeds a set threshold and / or the effluent turbidity is >1 NTU, the signal is transmitted through an electrically connected programmable logic controller to trigger an automatic backwashing program.

[0014] Furthermore, the agitator includes a central helical shaft and angled blades.

[0015] Furthermore, the lower layer of the gradient iron-carbon filler has a particle size of 50-200 nm and a filling density of 20-40%.

[0016] Furthermore, the coil-type temperature control module incorporates a PTC heating element and a circulating cooling channel, and is electrically connected to a programmable logic controller. The circulating cooling channel is connected to a cold water source, and the PTC heating element is connected to a power supply.

[0017] Furthermore, the micro-nano bubble generator in the pretreatment tank produces bubbles with a diameter of 10-100 μm. The micro-nano bubble generator has a built-in ozone generator, which loads ozone molecules onto the surface of the bubbles and mixes them with the wastewater through a Venturi jet.

[0018] The advantages and beneficial effects of this utility model are as follows:

[0019] 1. The pretreatment tank adopts a cyclone separation and ozone micro-nano bubble coupling technology. Through the physical cutting effect of 30-50μm bubbles and ozone oxidation, large particulate matter is removed and organic pollutants are pre-oxidized, reducing the load on subsequent treatment.

[0020] 2. The iron-carbon reaction tank uses layered packing to achieve graded treatment of pollutants: the upper layer of 2-5mm waste iron filings treats macromolecular organic matter through micro-electrolysis; the middle layer of iron powder-activated carbon composite packing (Fe / C mass ratio 3:1) generates a galvanic cell effect to enhance electron transfer; the bottom layer of nano-zero-valent iron (average particle size 80nm) utilizes its high specific surface area (>20m²) to achieve graded treatment of pollutants. 2 / g) achieves deep reduction of recalcitrant pollutants, with an overall COD removal rate 35% higher than that of traditional iron-carbon beds.

[0021] 3. The coil-type temperature control module controls the reaction temperature within the optimal range, ensuring the efficiency of the Fenton reaction and avoiding the exothermic reaction of the redox process and the changes in catalyst activity caused by the diurnal temperature difference.

[0022] 4. The surface of the catalytic composite membrane module is loaded with a Fe-Mn bimetallic catalyst to achieve a synergistic effect of filtration and catalytic oxidation. The gas-liquid pulse backwashing system improves the membrane flux recovery rate of the TMF depth filtration unit by alternately injecting compressed air and acid / alkali solutions via pulses. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of this utility model;

[0024] In the picture:

[0025] 1-Pretreatment tank, 2-Iron-carbon reaction tank, 3-First Fenton oxidation tank, 4-Second Fenton oxidation tank, 5-TMF depth filtration unit, 6-Cyclone separator, 7-Nano bubble generator, 8-Iron-carbon packing, 9-Agitator, 10-Coil-type temperature control module, 11-Catalytic composite membrane module, 12-Gas-liquid pulse backwashing system, 13-Membrane fouling early warning module, 14-High-pressure air tank, 15-Reagent storage tank, 16-Pulse controller, 17-Transmembrane differential pressure sensor, 18-Turbidity online monitor, 19-Central spiral shaft, 20-Inclined blade, 21-Venturi jet injector. Detailed Implementation

[0026] The specific embodiments of this utility model will be further described below with reference to the accompanying drawings and examples. The following examples are only used to more clearly illustrate the technical solution of this utility model and should not be construed as limiting the scope of protection of this utility model.

[0027] Example 1

[0028] This embodiment provides a high-efficiency Fenton oxidation reactor for treating organic wastewater containing phenol with a COD of 2000 mg / L from a chemical industrial park. The specific implementation steps are as follows:

[0029] Wastewater first enters pretreatment tank 1, where it undergoes physical separation via hydrocyclone separator 6 at a flow rate of 0.8-1.2 m / s to remove suspended solids with a particle size >50 μm. Nanobubble generator 7 is then activated, producing ozone micro-nanobubbles with a diameter of 30-50 μm (ozone concentration 5-8 mg / L). These micro-nanobubbles are thoroughly mixed with the wastewater via Venturi jet injector 21, with a residence time of 15-20 minutes. This ozone pre-oxidation degrades some phenol into smaller organic molecules, reducing COD by approximately 15%.

[0030] The pretreated wastewater flows into iron-carbon reaction tank 2. The gradient packing in the tank operates as follows: Upper layer: Filled with 2-5mm scrap iron (porosity ≥60%), wastewater retention time 30 minutes, pH adjusted to 3-4, producing Fe²⁺ and [H] through micro-electrolysis, initially decomposing macromolecular organic matter. Middle layer: Activated carbon-iron powder composite packing (Fe / C mass ratio 3:1), wastewater retention time 40 minutes, utilizing the galvanic cell effect to enhance electron transfer, further degrading medium-molecular-weight pollutants. Lower layer: Nano-zero-valent iron particles (average particle size 80 nm, packing density 30%), through high specific surface area catalytic reduction reaction, converting recalcitrant substances (such as chlorinated organics) into easily oxidizable products, increasing COD removal rate to 50%.

[0031] After the iron-carbon reaction returns to its original state, the wastewater sequentially enters the first Fenton oxidation tank 3 and the second Fenton oxidation tank 4, where 30% hydrogen peroxide (dosage 0.5-1.0 mL / L) is added and the stirrer 9 is started. The coil-type temperature control module 10 maintains the reaction temperature at 35-40℃ through PTC heating elements and prevents overheating through a circulating cooling channel (cooling water flow rate 10 L / min).

[0032] The wastewater undergoes a two-stage Fenton reaction with a total residence time of 2 hours. Hydroxyl radicals (·OH) oxidize and degrade the remaining organic matter, ultimately reducing the COD to below 150 mg / L. After oxidation, the wastewater enters the TMF deep filtration unit 5, where vertically staggered polyethersulfone catalytic composite membranes (pore size 0.01 μm) are used for filtration at an operating pressure of 0.2-0.4 MPa, retaining micron-sized suspended solids and colloids.

[0033] The membrane fouling early warning module 13 monitors the transmembrane pressure difference (threshold set at 50 kPa) and effluent turbidity (threshold 1 NTU) in real time. When either indicator exceeds the standard, the gas-liquid pulse backwashing system 12 is activated. The chemical storage tank 15 includes an acid storage tank and an alkali storage tank.

[0034] Air scavenging mode: High-pressure air tank 14 releases 0.6 MPa compressed air for 30 seconds to clear physical blockages on the membrane surface.

[0035] Pickling mode: Pump 1% dilute hydrochloric acid into the acid storage tank and soak for 10 minutes to dissolve inorganic scale.

[0036] Alkaline washing mode: 1% sodium hydroxide is pumped into the alkaline storage tank and soaked for 10 minutes to remove organic pollutants. After backwashing, the membrane flux recovery rate is ≥95%, and the final effluent turbidity is <0.5 NTU, COD <50 mg / L, meeting the discharge standards.

[0037] Example 2:

[0038] For a certain dyeing and printing wastewater (containing azo dyes, COD 3500 mg / L), the operating parameters were adjusted as follows: The ozone concentration in the pretreatment tank was increased to 10 mg / L, the micro-nano bubble diameter was set to 20-30 μm, and the pre-oxidation time was extended to 25 minutes, resulting in a 20% reduction in COD. In the iron-carbon reaction tank, the nano-zero-valent iron packing density in the lower layer was increased to 40%, and the reaction pH was adjusted to 2.5, improving the reduction efficiency of recalcitrant dyes by 30%. In the double Fenton oxidation tank, the hydrogen peroxide dosage was increased to 1.2 mL / L, and the reaction temperature was controlled at 38-42℃, achieving a total COD removal rate of 98%.

[0039] Each unit is linked by a programmable logic controller (PLC) to adjust the flow rate, reagent dosage, and temperature in real time. The membrane fouling early warning module 13 is interconnected with the pulse controller 16 to achieve fully automatic backwashing and ensure continuous and stable operation of the system.

[0040] The wastewater treated by this device achieves a total COD removal rate of >95%, a suspended solids content of <10 mg / L, and an operating cost that is 25% lower than that of the traditional Fenton process. The catalytic composite membrane module 11 has a lifespan of more than 2 years and exhibits significant anti-fouling performance.

[0041] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A Fenton oxidation reaction apparatus, characterized in that, The system includes a pretreatment tank (1), an iron-carbon reaction tank (2), a first Fenton oxidation tank (3), a second Fenton oxidation tank (4), and a TMF deep filtration unit (5) connected sequentially along the water flow direction. The pretreatment tank (1) is equipped with a cyclone separator (6) and a nano bubble generator (7). The iron-carbon reaction tank (2) is filled with a gradient iron-carbon packing material (8) in layers, including an upper layer of large-pore waste iron filings, a middle layer of activated carbon-iron powder composite packing material, and a lower layer of nano zero-valent iron particles. The first Fenton oxidation tank (3) and the second Fenton oxidation tank (4) are both equipped with a stirrer (9) and a coil-type temperature control module (10). The TMF deep filtration unit (5) includes a vertically staggered catalytic composite membrane module (11), a gas-liquid pulse backwashing system (12), and a membrane fouling early warning module (13).

2. The Fenton oxidation reactor according to claim 1, characterized in that, The catalytic composite membrane module (11) is a polyethersulfone substrate with a catalytic layer loaded on the surface and a membrane pore size of 0.005~0.05μm.

3. The Fenton oxidation reaction apparatus according to claim 1, characterized in that, The gas-liquid pulse backwashing system (12) includes a high-pressure air tank (14), a chemical storage tank (15), and a pulse controller (16), which can alternate between gas sweeping, acid washing, and alkaline washing modes.

4. The Fenton oxidation reactor according to claim 1, characterized in that, The membrane fouling early warning module (13) includes a transmembrane pressure differential sensor (17) and an online turbidity monitor (18). When the transmembrane pressure differential exceeds a set threshold and / or the effluent turbidity is >1 NTU, an automatic backwashing program is triggered.

5. The apparatus according to claim 1, characterized in that, The agitator (9) includes a central helical shaft (19) and tilting blades (20).

6. The apparatus according to claim 1, characterized in that, The lower layer of the gradient iron-carbon filler (8) has a particle size of 50-200 nm and a filling density of 20-40%.

7. The apparatus according to claim 1, characterized in that, The coil-type temperature control module (10) has a built-in PTC heating element and a circulating cooling channel.

8. The apparatus according to claim 1, characterized in that, The micro-nano bubble generator (7) in the pretreatment tank (1) produces bubbles with a diameter of 10-100μm. The micro-nano bubble generator has a built-in ozone generator, which loads ozone molecules on the surface of the bubbles and mixes them with wastewater through a Venturi jet (21).

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