Fenton reaction device for wastewater treatment

Abstract

The invention relates to the technical field of wastewater treatment, in particular to a Fenton reaction device for wastewater treatment, which comprises a plurality of reaction tanks, reaction cavities are formed in the reaction tanks, and the reaction tanks are provided with stirring mechanisms and are respectively used for performing primary oxidation, premixing and secondary oxidation, complex reaction and flocculation reaction treatment on wastewater; the plurality of reaction tanks are communicated in sequence; the agent adding device comprises a first agent adding mechanism and a second agent adding mechanism, the first agent adding mechanism comprises a rotary feeding disc, and the rotary feeding disc rotates in the middle of the reaction tank, is connected with the stirring mechanism and is used for rotationally adding a solid additive dissolving solution or a liquid additive or magnetic powder; and the second additive adding mechanism comprises an atomizing structure arranged in the reaction tank and is used for atomizing and spraying the liquid additive. The chemical mixing device has the effects of improving the chemical mixing efficiency and reducing local non-uniform mixing.

Description

Technical Field

[0001] The present application relates to the technical field of wastewater treatment, and in particular to a Fenton reaction device for wastewater treatment. Background Art

[0002] At present, the Fenton reaction is a classic advanced oxidation technology (AOPs). Its core principle is to use ferrous ions to catalyze the decomposition of hydrogen peroxide (H2O2) to generate highly oxidizing hydroxyl radicals, thereby efficiently decomposing difficult-to-degrade organic matter.

[0003] In the prior art, a Chinese patent with publication number CN116081903A discloses a Fenton method for deep treatment of wastewater, comprising the following steps: 1) adjusting the pH of the wastewater to acidic to obtain acidified wastewater; 2) introducing ozone under an external magnetic field, stirring and mixing, and continuing the reaction for 15 to 30 minutes to obtain primary oxidation wastewater; 3) adding ferrous salt to the primary oxidation wastewater, stirring and mixing, to obtain premixed wastewater; 4) adding hydrogen peroxide to the premixed wastewater, stirring and mixing, and continuing the reaction under an external magnetic field for 30 to 45 minutes to obtain secondary oxidation wastewater; 5) Aerating the secondary oxidation wastewater, and adding carbonate to adjust the pH value of the wastewater to 5-6 to obtain pre-neutralized wastewater; 6) Adding a complexing defluorinating agent to the obtained pre-neutralized wastewater, and adding magnetic powder, stirring and mixing, and continuously reacting for 10-20 minutes to obtain complexing reaction wastewater; 7) Adding alkali solution to the obtained complexing reaction wastewater, stirring and mixing, adjusting the pH value of the complexing reaction wastewater to 6-7, and continuously reacting for 10-15 minutes under stirring conditions to obtain secondary neutralization wastewater; 8) Adding a coagulant to the obtained secondary neutralization wastewater, stirring and mixing, and then precipitating and separating, the supernatant is the purified wastewater.

[0004] However, in implementing the various steps of the above method, a stirring tank is usually used for mixing and stirring. When preparing premixed wastewater, the addition of ferrous salt is usually carried out by dissolving it into a solution and then directly adding it to the stirring tank feed port. The direct addition method leads to a slow mixing rate, which in turn leads to local Fe 2+ Too high concentration will cause Fe 3+ Premature precipitation reduces catalytic efficiency and causes uneven mixing. Summary of the invention

[0005] In order to improve the mixing efficiency of reagents and reduce local uneven mixing, the present application provides a Fenton reaction device for wastewater treatment.

[0006] The present application provides a Fenton reaction device for wastewater treatment, which adopts the following technical solution: A Fenton reaction device for wastewater treatment, comprising: A plurality of reaction tanks are provided, each of which forms a reaction chamber and is provided with a stirring mechanism, and is used for performing primary oxidation, premixing and secondary oxidation, complexation reaction and flocculation reaction on the wastewater, respectively, and the plurality of reaction tanks are connected in sequence; The drug dosing device comprises a first dosing mechanism and a second dosing mechanism, wherein the first dosing mechanism comprises a rotating dosing disk, which rotates in the middle of the reaction tank and is connected to the stirring mechanism, and is used for rotating and dosing a solid additive dissolving solution or a liquid additive or magnetic powder; The second dosing mechanism includes an atomizing structure disposed in the reaction tank, and is used for atomizing and spraying liquid additives.

[0007] By adopting the above technical scheme, when treating wastewater, firstly, the wastewater is added to a reaction tank for primary oxidation, and then acid is added to the wastewater by rotating the feeding disk to adjust the pH value of the wastewater to acidic to obtain acidified wastewater, and ozone is introduced under the condition of an external magnetic field, stirred and mixed, and the reaction is continued for 15 to 30 minutes to obtain primary oxidation wastewater; then the primary oxidation wastewater is flowed into a reaction tank for premixing, and then a solution prepared by dissolving ferrous salt is added by rotating the feeding disk during stirring to obtain premixed wastewater; then hydrogen peroxide is added to the reaction tank by an atomizing mechanism, stirred and mixed, and a magnetic field is applied outside the reaction tank, and the reaction is continued for 30 to 45 minutes to obtain secondary oxidation wastewater, which is then aerated and carbonate is added to adjust The pH value of the wastewater is adjusted to 5-6 to obtain pre-neutralized wastewater; the pre-neutralized wastewater is passed into a reaction tank for complex reaction, and then a complex defluorinating agent is added through an atomizing structure, and magnetic powder is added through a rotating feeding plate, stirred and mixed, and the reaction is continued for 10-20 minutes to obtain complex reaction wastewater; alkali solution is added to the prepared complex reaction wastewater, stirred and mixed, the pH value of the complex reaction wastewater is adjusted to 6-7, and the reaction is continued for 10-15 minutes under stirring conditions to obtain secondary neutralization wastewater; then the secondary neutralization wastewater is passed into a reaction tank for flocculation reaction, and then a coagulant is added to the prepared secondary neutralization wastewater, and the mixture is stirred and mixed, and then precipitated and separated, and the supernatant is the purified wastewater, and the supernatant is discharged; wherein the premixing and secondary oxidation are carried out in the same reaction tank to improve the utilization rate of the reaction tank.

[0008] The first feeding mechanism and the second feeding mechanism are arranged to make it more convenient to add the dissolved solid additive solution and the liquid additive, and to mix them more evenly. The ferrous salt solution is easily oxidized when in excessive contact with air. In the step of adding the ferrous salt solution, the ferrous salt solution is added by rotating the solution in large droplets or by linear addition, so that the dispersion efficiency is improved, and the contact between the ferrous salt solution and oxygen is reduced, and the waste caused by premature oxidation of the ferrous salt solution is reduced. In addition, the ferrous salt solution is heated and cooled by the rotating addition method, and the ferrous salt solution is heated and cooled by the rotating addition method. 3+Precipitation risk; H2O2 atomization coverage area is increased, free radical utilization rate is improved, thereby making mixing uniform, improving resource utilization, reducing resource waste, improving agent mixing efficiency, and reducing local uneven mixing; and acid and base solvents are added through the first feeding mechanism and the second feeding mechanism, which is convenient for adjusting the pH value, and can make the solution dispersed evenly, facilitating rapid adjustment of the pH value.

[0009] Optionally, the rotation direction of the rotating feeding plate is opposite to the rotation direction of the stirring mechanism.

[0010] By adopting the above technical solution, the stirring mechanism rotates clockwise and the feeding plate rotates counterclockwise to form a shear flow field. The reverse rotation enhances turbulent mixing, further shortens the mixing time of the ferrous salt solution and the wastewater, enhances the catalyst activity, accelerates the mixing, and improves the wastewater treatment effect.

[0011] Optionally, the first dosing mechanism also includes a transmission assembly, the transmission assembly includes a first gear, a second gear and a ring gear, the first gear is coaxially arranged with the stirring mechanism, the second gear rotates on the reaction tank and meshes with the first gear, the ring gear rotates on the reaction tank and meshes with the second gear, and the ring gear is connected to the rotating feeding plate.

[0012] By adopting the above technical solution, when the stirring mechanism is stirring and rotating, the first gear is driven to rotate, so that the first gear drives the second gear to rotate, the second gear drives the ring gear to rotate, and the ring gear drives the rotating feeding disk to rotate, so that the stirring mechanism and the rotating feeding disk rotate in opposite directions, the movement trajectories of the wastewater and the dissolved solid additive are in opposite directions, and a collision occurs, thereby increasing the contact and contact time between the wastewater and the solid additive dissolved solution, and the collision can accelerate the mixing effect, increase the mixing efficiency, and improve the wastewater treatment effect.

[0013] Optionally, the atomization structure is arranged on the outside of the rotating feeding disk.

[0014] By adopting the above technical scheme, when adding liquid hydrogen peroxide, it can be added simultaneously with the ferrous salt solution, or the ferrous salt can be dissolved and stirred for reaction first, and then the hydrogen peroxide can be added; in other reaction tanks, the timing of adding the solid additive dissolving solution and the liquid additive can be adjusted according to the process requirements. When adding at the same time, or when there is an overlapping addition time, the solid additive dissolving solution is rotated and separated to contact and collide with the atomized liquid additive, so that the liquid additive adheres to the solid additive dissolving solution and then mixes with the wastewater, which is convenient for improving the reaction efficiency and making the solid additive dissolving solution and the liquid additive mixed evenly, thereby improving the wastewater treatment effect; and for solutions with high requirements for acid-base environment, through the mixed addition of the first dosing mechanism and the second dosing mechanism, the solution can adapt to the acid-base environment in advance, quickly start the catalytic effect, reduce the addition of acid-base regulating liquid, and improve resource utilization.

[0015] Optionally, the atomization structure includes a ring tube, an atomizing nozzle and a supply assembly, the ring tube is arranged in the reaction tank, the ring tube is connected to the supply assembly, the supply assembly is arranged on the reaction tank, and is used to provide liquid reactants; the atomizing nozzle is provided in plurality and is evenly arranged on the ring tube, and the end of the atomizing nozzle close to the bottom of the reaction tank is close to the rotating feeding plate.

[0016] By adopting the above technical solution, the agent supply component supplies liquid additives into the annular tube and forms a spray through the atomizing nozzle, which fully contacts the wastewater, thereby improving the mixing effect of the liquid additives, improving the reaction efficiency, and improving the treatment of wastewater.

[0017] Optionally, a reflux mechanism is provided on the reaction tank, and the reflux mechanism includes an inlet pipe, a reflux pump and a return pipe, the inlet pipe is arranged at the bottom of the reaction tank; the reflux pump is arranged on the reaction tank, the water inlet end is connected to the inlet pipe, and the water outlet end is connected to the return pipe; the return pipe is arranged at the upper part of the side wall of the reaction tank and is connected to the reaction chamber.

[0018] By adopting the above technical solution, during the stirring process, or when adding a solid additive dissolving solution and / or adding a liquid additive, the reflux pump is started, and the reflux pump pumps out the waste water in the reaction tank through the water inlet pipe, and then returns it to the upper layer of the reaction tank through the return pipe, thereby increasing the mixing effect and making the addition of the solid additive dissolving solution or the liquid additive more uniform, thereby improving the reaction efficiency.

[0019] Optionally, one end of the water return pipe located in the reaction chamber has a flat outlet and is located on a side of the atomization structure close to the bottom of the reaction tank.

[0020] By adopting the above technical solution, the flat outlet increases the contact area between the sprayed wastewater and the solid additive solution or liquid additive, further improving the mixing effect, facilitating the oxidation reaction, and improving the mixing effect.

[0021] Optionally, a guide plate is provided in the reaction tank to guide the water sprayed from the return pipe and form a laminar flow.

[0022] By adopting the above technical solution and setting the guide plate, the sprayed water area is larger, which further increases the contact area with the solid additive solution or liquid additive, makes the mixing more uniform, improves the reaction efficiency and reaction effect, and at the same time, can also reduce the waste of reactants.

[0023] Optionally, the guide plate is arranged around the stirring mechanism, and one end close to the stirring mechanism is inclined close to the bottom of the reaction tank.

[0024] By adopting the above technical scheme, the wastewater mixed with the solid additive solution and / or the liquid additive is approached to the stirring mechanism through the guide plate, so that the stirring mechanism rotates and beats the mixed wastewater, thereby improving the reaction effect, and makes the wastewater approach the outside of the reaction tank, causing impact on the wastewater in the reaction tank, thereby improving the mixing reaction effect.

[0025] Optionally, a beating plate is provided on the stirring mechanism, and the beating plate rotates with the stirring mechanism and beats the water flowing down from the guide plate.

[0026] By adopting the above technical solution, the beating plate rotates to hit the mixed wastewater or breaks up the prematurely formed flocs, thus avoiding the premature formation of Fe 3+ Sedimentation improves the complexing effect and breaks up large particles, which facilitates the full reaction of the carboxylic acid iron complex with organic pollutants, improves the wastewater treatment effect, makes the floc particle size uniformly reduced, shortens the sedimentation time, and at the same time can reduce the sludge moisture content and improve the filter press efficiency.

[0027] In summary, the present application includes at least one of the following beneficial technical effects: 1. Through multiple tanks to carry out different reaction processes, the generation of by-products is reduced, so that the COD removal rate is improved. The addition method of solid additives dissolving solution and liquid additives improves the mixing uniformity and reduces the waste of reagents; 2. The rotating feeding plate and stirring mechanism rotate in opposite directions, and the diversion laminar flow is set to improve the reaction efficiency and reduce energy consumption; 3. Through the use of beating plates for crushing and closed-loop diversion, the sludge volume is reduced and the filter pressing cost is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a diagram of the connection system between the reaction tanks in the embodiment of the present application; Figure 2 It is a display diagram of the reaction tank in the embodiment of the present application; Figure 3 is a cross-sectional view of a reaction tank in an embodiment of the present application; Figure 4 It is a display diagram of the ring tube in the embodiment of the present application; Figure 5 is a cross-sectional view of a rotating feeding plate in an embodiment of the present application; Figure 6 It is a three-dimensional structural diagram of the rotating feeding plate in the embodiment of the present application; Figure 7 It is a display diagram of the feeding hole in the embodiment of the present application; Figure 8 yes Figure 5 A partial enlarged view of area A in the middle.

[0029] Reference numerals: 100, reaction tank; 110, first tank; 120, second tank; 130, third tank; 140, fourth tank; 150, venturi mixer; 170, waste pipe; 180, liquid discharge pipe; 190, reaction chamber; 200, stirring mechanism; 210, rotating shaft; 220, motor; 230, paddle; 300, first dosing mechanism; 310, rotating feeding plate; 311, cylindrical barrel; 312, dispersion plate; 313, fixed plate; 3 14. delivery area; 315. storage chamber; 316. feeding hole; 320. transmission assembly; 321. first gear; 322. second gear; 323. gear ring; 330. rotating frame; 340. feeding bin; 400. second dosing mechanism; 410. annular pipe; 420. atomizing nozzle; 500. reflux mechanism; 510. water inlet pipe; 520. reflux pump; 530. water return pipe; 610. guide plate; 620. beating plate; 630. support frame. DETAILED DESCRIPTION

[0030] The following combination Figures 1 to 8 This application is described in further detail.

[0031] This embodiment discloses a Fenton reaction device for wastewater treatment.

[0032] Reference Figure 1 and Figure 2The Fenton reaction device of the present invention comprises a plurality of reaction tanks 100 connected in series, a reagent dosing device and a matching stirring mechanism 200, a reflux mechanism 500 and a diversion structure; the plurality of reaction tanks 100 are sequentially connected along the flow direction of the wastewater through a Venturi mixer 150, and are respectively used for primary oxidation, premixing and secondary oxidation, complex reaction and flocculation reaction, and also comprises a liquid discharge pipe 180 for discharging supernatant and a waste discharge pipe 170 for discharging waste materials arranged on the last reaction tank 100; wherein the premixing and secondary oxidation stages share the same reaction tank 100, and the stirring mechanism 200 and the reagent dosing device cooperate to complete the uniform or mixed addition of the solid additive dissolving solution and the liquid additive, and complete each process step.

[0033] A plurality of reaction tanks 100 are arranged in a straight line, preferably four in this embodiment, and are named as the first tank 110, the second tank 120, the third tank 130 and the fourth tank 140 according to the reaction order. The adjacent tank bodies are connected through a venturi mixer 150, and the lower end of the reaction tank 100 for the pre-reaction and the upper end of the reaction tank 100 for the post-reaction are connected. The tank body is made of 316L stainless steel, the inner wall is polished (Ra≤0.8μm), the volume is 2-5m³, and it is configured according to the processing scale. A cylindrical reaction chamber 190 is formed inside each reaction tank 100, and a feeding port for pH adjustment with a sealing cover is provided on the top, and a slag discharge valve is provided at the bottom. The height of the premixing and secondary oxidation reaction tank 100 is 1.2 times that of other tank bodies to extend the reaction residence time, and an external magnetization device, a magnetization device electromagnet, is arranged on the outside of the reaction tank 100 for adjustment according to the magnetic field requirements.

[0034] The waste pipe 170 is fixedly connected to the bottom wall of the reaction tank 100 and is connected to the reaction chamber 190, and a control valve is provided. The liquid discharge pipe 180 is located on the side wall of the reaction tank 100 and close to the upper part, and one end is located in the reaction tank 100, and the end located in the reaction tank 100 extends toward the bottom wall of the reaction tank 100, and a plurality of water inlet holes are opened on the side wall, and the water inlet holes are evenly distributed along the length direction thereof; and booster pumps are provided on both the liquid discharge pipe 180 and the waste discharge pipe 170 to facilitate liquid and waste discharge.

[0035] An aeration mechanism is provided in the reaction tank 100, and the aeration mechanism includes an aeration head and an air source. The aeration head is provided inside the reaction tank 100 and close to the bottom, and the air source is provided on the outside and connected to the aeration head. The air source is used to supply air or ozone to form an aeration effect. Whether aeration is required and what kind of gas to be aerated can be selected according to the process steps.

[0036] Reference Figure 3The stirring mechanism 200 includes a support frame 630 fixedly connected to the reaction tank 100, a vertically arranged rotating shaft 210 and three groups of blades 230, and the three groups of blades 230 are arranged along the length direction of the rotating shaft 210. The rotating shaft 210 is rotatably connected to the top wall of the reaction tank 100, and is coaxial with the reaction tank 100, and is rotatably connected to the support frame 630, and the top of the rotating shaft 210 passes through the support frame 630 and is connected to the motor 220; the part of the rotating shaft 210 located in the reaction tank 100 is fixedly connected to a plurality of slapping plates 620, and the slapping plates 620 are arranged at equal intervals along the circumference of the rotating shaft 210, and the slapping plates 620 are rectangular steel plates, and are located above the liquid level of the reaction tank 100.

[0037] The reflux mechanism 500 includes an inlet pipe 510, a reflux pump 520 and a return pipe 530. The inlet pipe 510 is arranged at the bottom center of the reaction tank 100 and is connected to the inside of the reaction tank 100 through a three-way control valve. The venturi mixer 150 is connected to the other outlet of the three-way control valve. The return pump is detachably connected to the side wall of the reaction tank 100 by bolts, and the inlet pipe 510 is connected to the inlet of the reflux pump 520. The return pipe 530 is inserted from the side wall of the tank body and is located at the upper part of the reaction tank 100. The end of the return pipe 530 is higher than the height of the flapping plate 620 and the paddle 230. The long side of the flat outlet at the end is arranged horizontally. The outlet plane corresponds to the guide structure, which is the guide plate 610. The guide plate 610 is an arc-shaped stainless steel plate, which is radially arranged around the rotating shaft 210 at an inclination angle of 15°, and the end close to the rotating shaft 210 is close to the bottom of the reaction tank 100. The upper end is flush with the flat outlet of the return pipe 530, and the jet direction is toward the guide plate 610, and there is a 3° angle with the guide plate 610; and the lower end of the guide plate 610 is 40mm-50mm higher than the height of the flapping plate 620. The flow rate of the reflux pump 520 is adjustable, and the maximum circulation volume is 3 times the tank volume / hour.

[0038] Reference Figure 4 and Figure 5The drug dosing device includes a first dosing mechanism 300 and a second dosing mechanism 400; the first dosing mechanism 300 and the second dosing mechanism 400 are both provided in plurality and correspond to a plurality of reaction tanks 100 respectively; wherein the first dosing mechanism 300 is used for adding a solid additive dissolving solution, and includes a rotating frame 330, a rotating feeding disk 310, a feeding bin 340 and a transmission assembly 320, the rotating frame 330 is fixedly connected to the support frame 630, and a connecting ring is integrally provided on the rotating frame 330, and the connecting ring is arranged around the rotating shaft 210 and is rotatably connected to the rotating shaft 210; the rotating feeding disk 310 includes two cylindrical barrels 311, a fixed disk 310, and a rotating frame 330. 3 and a plurality of dispersion plates 312, the two cylindrical barrels 311 are concentrically sleeved, the length of the outer cylindrical barrel 311 is shorter than the length of the inner cylindrical barrel 311, the fixed disk 313 is fixedly connected to one end of the inner cylindrical barrel 311 located in the reaction chamber 190, and is rotatably connected to the rotating shaft 210, the plurality of dispersion plates 312 are fixedly connected to the fixed disk 313, and connect the outer cylindrical barrel 311 and the inner cylindrical barrel 311, the plurality of dispersion plates 312 are arranged at equal intervals along the circumference of the fixed disk 313, and form a plurality of delivery areas 314 that are not connected to each other, the channel formed between the two cylindrical barrels 311 is a storage cavity 315, and the storage cavity 315 is connected to the delivery area 314.

[0039] Reference Figure 6 and Figure 7 , a plurality of feeding holes 316 are provided on the outer cylindrical tube 311, the feeding holes 316 are located in the rotating frame 330 and outside the reaction tank 100, and the feeding holes 316 are connected to the storage chamber 315; a plurality of feeding bins 340 are provided, and each is provided with an electromagnetic control valve, the discharge end of the feeding bin 340 is fixedly connected to the rotating frame 330, and extends to the outer cylindrical tube 311 of the rotating feeding disk 310, and is rotatably sealed and connected to and communicated with a side of the rotating feeding disk 310 where the feeding holes 316 are provided; the transmission assembly 320 is provided on the rotating shaft 210 of the stirring mechanism 200, is connected to the rotating frame 330 and the rotating feeding disk 310, and drives the rotating feeding disk 310 to rotate, and the rotation direction of the rotating feeding disk 310 is opposite to the rotation direction of the rotating shaft 210.

[0040] Reference Figure 8 The transmission assembly 320 includes a first gear 321 coaxially fixed on the rotating shaft 210 of the stirring mechanism 200, a second gear 322 meshing with the first gear 321, and a ring gear 323 whose inner circumference is meshing with the second gear 322, wherein the second gear 322 is detachably rotatably connected to the support frame 630 by bolts, the ring gear 323 is rotatably connected to the support frame 630, and the ring gear 323 is fixedly connected to the rotating feeding plate 310, driving the rotating feeding plate 310 to rotate in the opposite direction of the rotating shaft 210.

[0041] The second dosing mechanism 400 is used to atomize liquid dosing agents, and includes a ring tube 410, an atomizing nozzle 420, and a dosing assembly. The ring tube 410 is arranged horizontally around the outer edge of the rotating feeding disk 310, and the height of the ring tube 410 is higher than the lower surface of the rotating feeding disk 310; the ring tube 410 is fixed to the inner wall of the tank body by a bracket, and 12 atomizing nozzles 420 are evenly welded on its periphery, and the nozzles are tilted downward 30° to the edge of the feeding disk. The dosing assembly includes a metering pump and a liquid storage tank, which are arranged on the outside of the reaction tank 100 and connected to the ring tube 410 by a hose, and are used to supplement the liquid additive to the ring tube 410.

[0042] The reagents are added in coordination with the rotating feeding disc 310 and the atomizing structure to achieve efficient mixing and reaction; the first dosing mechanism 300 is used for adding solutions that are easily oxidized or used in large quantities, and large droplets or linear water columns are formed by the rotating dosing of the rotating feeding disc 310; the second dosing mechanism 400 is used for adding solutions that are not easily oxidized, are added in small quantities or last for a long time, and filtering is required during addition to reduce clogging; for the addition of the same solution, the first dosing mechanism 300 and the second dosing mechanism 400 can be mixed and added to improve the addition efficiency, and the addition of the pH value adjusting solvent can also be added through the above two structures.

[0043] Each reaction tank 100 is provided with a stirring mechanism 200, whose rotating shaft 210 vertically penetrates the center of the tank body and drives the rotating feeding plate 310 to rotate in the opposite direction through the transmission assembly 320. The water inlet pipe 510 arranged at the bottom of the reaction tank 100 and the return pipe 530 with a flat outlet arranged on the top side wall realize circulation mixing through the reflux pump 520. The guide plate 610 is arranged obliquely around the stirring mechanism 200, and cooperates with the flapping plate 620 to enhance the floc breaking effect, while forming a laminar flow, and cooperates with the atomization structure and the rotating feeding plate 310 to increase the contact between the wastewater and the solid additive solution and / or liquid additive.

[0044] When treating wastewater, the following steps are followed: first, the pH value of the wastewater is adjusted to acidic, and then an oxidation step is performed, and a pH adjuster can be mixed and added through the first dosing mechanism 300 and / or the second dosing mechanism 400.

[0045] Primary oxidation: Acidified wastewater is injected from the top of the first reaction tank 100, and the stirring mechanism 200 rotates clockwise at 120 rpm. At the same time, ozone is introduced from the aeration head at the bottom of the tank. At this time, the rotating feeding plate 310 is driven by the transmission assembly 320 to rotate counterclockwise at 80 rpm to form a shear flow field. The second gear 322 can also be removed to stop the rotation of the rotating feeding plate 310.

[0046] Premixing and secondary oxidation: After the wastewater flows into the second reaction tank 100, the ferrous salt solution is evenly scattered through the rotating feeding plate 310. By adjusting the supply speed, it can be controlled to form large droplets or linear water columns. The ferrous salt solution and the wastewater rotating in the opposite direction collide and dissolve violently to form premixed wastewater; after 15 minutes, the atomizing nozzle 420 is turned on, and the 30% hydrogen peroxide solution forms a conical mist curtain to cover the falling area of ​​the rotating feeding plate 310. At the same time, the reflux pump 520 extracts the bottom wastewater at 2 times the flow rate and sprays it to the guide plate 610 in a fan shape through the flat outlet. The water flows down along the guide plate 610 in a laminar flow, contacts and mixes with the atomized hydrogen peroxide, and the wastewater continues to fall and is broken by the flapping plate 620 to generate micro-vortices, which promotes Fe 2+ Fully contact with H2O2; and during the process of adding hydrogen peroxide and stirring, an external magnetic field is applied, and the reaction is continued for 30 to 45 minutes to form secondary oxidation wastewater.

[0047] Secondary aeration: aerate the secondary oxidation wastewater with an aeration head. Ozone aeration or air aeration can be used for aeration. In this embodiment, ozone aeration is preferably used. Then, carbonate is added through the feed port above the reaction tank 100 or the first dosing mechanism 300 and / or the second dosing mechanism 400 to adjust the pH value to 5-6 to obtain pre-neutralized wastewater. Complex reaction; the pre-neutralized wastewater is passed into a reaction tank 100 for complex reaction, and then a complex defluorinating agent is added through an atomizing structure, and magnetic powder is added through a rotating feeding disk 310, wherein the complex defluorinating agent and the magnetic powder are added simultaneously, and the magnetic powder is interfered by the rotating feeding disk 310, rotates and contacts with the complex defluorinating agent, and then enters the wastewater, and is continuously stirred and mixed, and the reaction is continuously carried out for 10 to 20 minutes to obtain complex reaction wastewater; alkali solution is added to the prepared complex reaction wastewater, and the mixture is stirred and mixed, and the pH value of the complex reaction wastewater is adjusted to 6 to 7, and the reaction is continuously carried out for 10 to 15 minutes under stirring conditions to obtain secondary neutralization wastewater.

[0048] Flocculation reaction: the secondary neutralization wastewater is then passed into the reaction tank 100 for flocculation reaction, and then a coagulant is added to the obtained secondary neutralization wastewater, and the mixture is stirred and mixed, and then precipitated and separated. The supernatant is the purified wastewater, and the supernatant and the generated precipitate are discharged separately.

[0049] In other embodiments, in the premixing and secondary oxidation steps, hydrogen peroxide and ferrous salt dissolved solution can be added at the same time. When adding, the input ratio is controlled so that hydrogen peroxide and ferrous salt dissolved solution are evenly mixed and then enter the wastewater. Premixing and secondary oxidation are carried out simultaneously, so that the reaction efficiency is improved and the waste of reagents can be reduced.

[0050] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A Fenton reaction device for wastewater treatment, characterized in that: include: A plurality of reaction tanks (100) are provided, each of which forms a reaction chamber (190) therein and is provided with a stirring mechanism (200), and is used to perform primary oxidation, premixing and secondary oxidation, complex reaction and flocculation reaction treatment on the wastewater, respectively; the plurality of reaction tanks (100) are connected in sequence; A drug dosing device comprises a first dosing mechanism (300) and a second dosing mechanism (400), wherein the first dosing mechanism (300) comprises a rotating dosing disk (310), the rotating dosing disk (310) rotates in the middle of the reaction tank (100), is connected to the stirring mechanism (200), and is used for rotatingly dosing a solid additive dissolving solution or a liquid additive or magnetic powder; The second dosing mechanism (400) comprises an atomizing structure arranged in the reaction tank (100) and used for atomizing and spraying liquid additives.

2. The Fenton reaction device for wastewater treatment according to claim 1, characterized in that: The rotation direction of the rotating feeding disk (310) is opposite to the rotation direction of the stirring mechanism (200).

3. The Fenton reaction device for wastewater treatment according to claim 2, characterized in that: The first dosing mechanism (300) further comprises a transmission assembly (320), the transmission assembly (320) comprising a first gear (321), a second gear (322) and a ring gear (323), the first gear (321) being coaxially arranged with the stirring mechanism (200), the second gear (322) rotating on the reaction tank (100) and meshing with the first gear (321), the ring gear (323) rotating on the reaction tank (100) and meshing with the second gear (322), and the ring gear (323) being connected to the rotating dosing plate (310).

4. The Fenton reaction device for wastewater treatment according to claim 1, characterized in that: The atomization structure is arranged on the outside of the rotating feeding disk (310).

5. The Fenton reaction device for wastewater treatment according to any one of claims 1 to 4, characterized in that: The atomization structure comprises an annular tube (410), an atomizing nozzle (420) and a reagent supply assembly. The annular tube (410) is arranged in the reaction tank (100). The annular tube (410) is connected to the reagent supply assembly. The reagent supply assembly is arranged on the reaction tank (100) and is used to provide liquid reactants. A plurality of atomizing nozzles (420) are arranged evenly on the annular tube (410). One end of the atomizing nozzle (420) close to the bottom of the reaction tank (100) is close to the rotating feeding disk (310).

6. The Fenton reaction device for wastewater treatment according to claim 1, characterized in that: The reaction tank (100) is provided with a reflux mechanism (500), the reflux mechanism (500) comprising a water inlet pipe (510), a reflux pump (520) and a water return pipe (530), the water inlet pipe (510) being arranged at the bottom of the reaction tank (100); the reflux pump (520) being arranged on the reaction tank (100), with a water inlet end connected to the water inlet pipe (510) and a water outlet end connected to the water return pipe (530); the water return pipe (530) being arranged at an upper portion of a side wall of the reaction tank (100) and being in communication with the reaction chamber (190).

7. The Fenton reaction device for wastewater treatment according to claim 6, characterized in that: One end of the water return pipe (530) located in the reaction chamber (190) has a flat outlet and is located on a side of the atomization structure close to the bottom of the reaction tank (100).

8. The Fenton reaction device for wastewater treatment according to claim 6, characterized in that: A guide plate (610) is provided in the reaction tank (100) for guiding the water sprayed out of the return pipe (530) and forming a laminar flow.

9. The Fenton reaction device for wastewater treatment according to claim 8, characterized in that: The guide plate (610) is arranged around the stirring mechanism (200), and one end close to the stirring mechanism (200) is inclined close to the bottom of the reaction tank (100).

10. The Fenton reaction device for wastewater treatment according to claim 8, characterized in that: The stirring mechanism (200) is provided with a beating plate (620), and the beating plate (620) rotates with the stirring mechanism (200) and beats the water flowing down from the guide plate (610).

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