CN107651747B - Three-phase single-baffle inner circulation Fenton fluidized bed wastewater treatment device and process - Google Patents

Abstract

The invention discloses a three-phase single baffle inner loop Fenton fluidized bed wastewater treatment device and a process thereof. The device includes a fluidized bed reactor tower body, a circulating pipeline, a water inlet pipeline, a dosing device, a water outlet pipeline, and an air inlet pipe. There is a uniform water distributor at the bottom of the tower; the interface at the side wall of the tower bottom is provided with a dosing device, 1/3 of the side wall is connected to the light source device, and 2/3 of the tower body is equipped with a solid-liquid separator. The following part of the solid-liquid separator is as follows: In the Fenton reaction zone of the fluidized bed, a single baffle is arranged at 1/3 of the diameter of the reaction zone, and a water outlet is opened at the side wall of the settlement zone 10 cm above the circulation interface. The device and its process are simple in operation, high in efficiency, small in floor space and simple in maintenance; the dosage of Fenton reagent is reduced, the chemical sludge is produced less, and the operation cost is low.

Description

A three-phase single-baffle inner-circulating Fenton fluidized bed wastewater treatment device and process

technical field

The invention belongs to the technical field of treating industrial wastewater. It specifically relates to a three-phase single-baffle inner-circulation Fenton fluidized bed processing method for organic wastewater.

Background technique

With the development of society and economy, many industries will produce a large amount of industrial wastewater in the production process, such as pulping wastewater, oily wastewater, etc. These wastewaters have large discharge, high pollutant content, many components, deep color, difficult Degradation and other characteristics, but at present, after relying solely on conventional biochemical and physicochemical methods, there are still some refractory organic substances in the discharged water. Increasingly stringent, more efficient wastewater treatment processes and technologies must be adopted. As a new type of advanced oxidation technology, Fenton technology has attracted more and more attention both inside and outside the industry, and has become the most potential clean water technology. The Fenton system is that H ₂ O ₂ generates hydroxyl radicals with strong oxidizing ability under the catalysis of Fe ²⁺ . When ultraviolet light, visible light, oxygen, oxalate, etc. are introduced into the Fenton system, the generation of hydroxyl radicals can also be increased. Free radical efficiency, has a significant effect on the treatment of organic matter. Since the Fenton system has the advantages of no toxicity of reagents during use, no obstruction of mass transfer in homogeneous system, simple operation, and relatively small investment, it has been widely used in the treatment of toxic and harmful wastewater.

The reason why the Fenton reagent in the Fenton system has a strong oxidizing ability is that H ₂ O ₂ is reduced and decomposed by Fe ²⁺ to generate hydroxyl radicals, and more other radicals are induced. The reaction mechanism is as follows:

Fe ²⁺ +H ₂ O ₂ →Fe ³⁺ +OH ^- + OH

Fe ³⁺ +H ₂ O ₂ →Fe ²⁺ +HO ₂ +H ⁺

Fe ²⁺ + OH→OH ^- +Fe ³⁺

RH+·OH→R·+H ₂ O

R +Fe ³⁺ →R ⁺ +Fe ²⁺

R ⁺ +O ₂ →ROO ⁺ →··→CO ₂ +H ₂ O

From the above chain reaction process, it can be seen that:

(1) Compared with other strong oxidants, hydroxyl radicals have higher redox potential (E=2.80V), and are the strongest oxidants except F ₂ ;

(2) The oxidation of Fenton's reagent has no selectivity and can be applied to the treatment of various organic substances. And the reaction efficiency is high, it can be carried out at normal temperature and pressure, and no complicated reaction system is required;

(3) Since the redox potential of the hydroxyl radical is E=2.80V, when a light source, such as ultraviolet light and visible light is added, electron transition can be excited, and the electron transfer efficiency can be improved, thereby improving the catalytic efficiency.

There are also some problems in the Fenton system at present, such as the low utilization rate of hydrogen peroxide and Fe ²⁺ ions; huge consumption of chemicals and high operating costs. Therefore, more researchers improve these problems through improved Fenton technology, such as optical Fenton, electric Fenton, Fenton fluidized bed and other Fenton combination technologies.

SUMMARY OF THE INVENTION

The purpose of the present invention is to solve the problems of low reaction efficiency and high operating cost of the existing homogeneous Fenton system. By using the heterogeneous Fenton system, improving the structure of the reactor, and adding a light source to improve the reaction efficiency, the consumption of chemicals can be significantly reduced. Utilization of hydrogen peroxide and ferrous ions.

Therefore, in the improved heterogeneous Fenton process of the present invention, relying on the fluidized bed Fenton reactor, the purpose is achieved through the improved catalyst and optimized reaction adjustment, and its specific scheme is as follows:

A three-phase single baffle inner loop Fenton fluidized bed treatment device, comprising a fluidized bed reactor tower body 1, a circulation pipeline 2, a water inlet pipeline 3, a dosing pipeline 4, a water outlet pipeline 5, and an air inlet pipe 9, which is characterized by:

The top of the fluidized-bed reactor tower body 1 is open, the sidewall of the fluidized-bed reactor tower body close to the open top is provided with a water outlet pipeline 5, and the bottom of the fluidized-bed reactor tower body is provided with uniform distribution pipes. Water device 11, the water distributor is communicated with the water inlet 16 located at the bottom of the fluidized bed reactor tower body, and a solid-liquid separator is installed horizontally at the height of the tower body above 1/2 (preferably 2/3). 12. The circulation interface 15 provided on the side wall of the fluidized bed reactor tower body close to the solid-liquid separator 12 above the solid-liquid separator 12; the solid-liquid separator 12 The bed reactor tower body 1 is divided into upper and lower parts, and the part below the solid-liquid separator 12 is the fluidized bed Fenton reaction zone. A vertical single baffle 14, one side of the single baffle 14 is fixed on the side wall of the column body 1 of the fluidized bed reactor; one end of the circulation pipeline 2 is connected to the fluidized bed The side wall above the solid-liquid separator of the reactor tower is connected with the circulation interface 15, and the other end is connected with the water inlet 16 at the bottom of the tower body. The circulation pipeline 2 is arranged with a stop valve in the middle. 8, the connecting pipeline 31 communicates with the water inlet pipeline 3, and a pressurizing pump 61 is arranged between the connecting pipeline 31 and the water inlet pipeline 3; the circulation pipeline 2. A circulating pump 21 is provided between the position close to the water inlet 16 and the connecting pipeline;

The fluidized bed Fenton reaction zone is provided with a feed port 17 near the side wall of the tower body of the uniform water distributor; the dosing pipeline 4 includes a FeSO ₄ dosing pipeline 41 and a hydrogen peroxide dosing pipeline 42. The FeSO ₄ dosing pipeline and the hydrogen peroxide dosing pipeline are respectively connected to the feed port 17 through the corresponding pressurizing pumps 63 and 64, and the air intake pipe 9 is also connected to the feed port through the air pump 62. 17 Connected.

Preferably, the plane on which the single baffle plate 14 of the present invention is located falls at 2/3 of the diameter of the circular section passing through the central axis of the fluidized bed reactor tower body 1 perpendicular to the plane.

Further, in the present invention, the FeSO ₄ dosing pipeline 41 , the hydrogen peroxide dosing pipeline 42 , the connecting pipeline 31 , and the air intake pipe 7 are all provided with corresponding flow meters.

Further, the circulation pipeline 2 , the dosing pipeline 4 , the water outlet pipeline 5 , and the air intake pipe 9 of the present invention are all provided with stop valves.

Further, the dosing pipeline 4 and the water outlet pipeline 5 of the present invention are both equipped with filter screens, and the mesh number of the filter screens is 200-300 meshes.

Further, the uniform water distributor 11 of the present invention is in the shape of a round cake, and water outlet holes are evenly distributed on the surface of the round cake.

Further, 30-50 holes are evenly opened on the round cake-shaped surface of the present invention, and each hole diameter is 2-10 mm.

Further, the water outlet pipeline 5 of the present invention is located on the side wall of the column body of the fluidized bed reactor above the circulation interface 15 .

Further, the present invention provides a process for treating wastewater by applying the three-phase single-baffle inner-circulating Fenton fluidized bed treatment device, comprising the following steps:

(1) Dilute the waste water to be treated to a COD of 400-900 mg/L, adjust the pH to 3-4, and inject it into the fluidized bed reactor through the water inlet pipeline 3, the connecting pipeline 31 and the circulating pump 21 in turn, and connect the The flowmeter on the pipeline controls the waste water flow to be 20-50mL/min; before the reaction starts, iron filings that account for 5-10wt% of the diluted waste water are blown into the reactor through the _FeSO4 dosing pipeline 41;

(2) When the liquid level of the waste water rises to approach the solid-liquid separator 12, turn on the light source device 13, close the water inlet pipe 31, the circulating pump 21 continues to work, and open the air inlet pipe 9, at this time, the blown air pushes the waste water to fluidize Circulating flow in the bed Fenton reaction zone, and keeping the air flow at 200-1000mL/min by controlling the flow meter;

(3) After the liquid level reaches above the solid-liquid separator 12 and submerges the circulation interface 15, part of the waste water re-enters the reactor through the circulation pipeline 2. At this time, the water inlet pipeline 31 and the dosing pipeline 4 are opened, and the configuration is completed. _The H ₂ O ₂ aqueous solution is blown into the reactor from the _hydrogen peroxide dosing pipeline 42, and the flow rate is controlled to be 5-10 mL/min. mol/L;

At the same time, the prepared FeSO ₄ aqueous solution and/or the iron-supported solid catalyst solution is blown into the reactor from the FeSO ₄ dosing pipeline 41, and the H 2 O 2 in the prepared H ₂ O ₂ aqueous solution is mixed with the prepared H ₂ O ₂ aqueous solution. The _FeSO4 aqueous solution and/or the iron-supported solid catalyst solution has a material ratio of Fe ²⁺ of 5 to 20:1; the iron-supported solid catalyst is a solid catalyst with a Fe ²⁺ load of 5 to 10%. ;

At this time, the effluent of the uniform water distributor 11 maintains a certain rising speed, the liquid in the fluidized bed reactor circulates on both sides of the single baffle 14, and the iron-supported solid catalyst and iron filings are in a fluidized state; Fe ²⁺ and H ₂ The Fe ³⁺ generated by the oxidation reaction of O ₂ is adsorbed on the surface of the iron-supported solid catalyst and iron filings in the form of crystalline precipitation;

(4) After passing through the solid-liquid separator, the iron filings and the iron-supported solid catalyst in the wastewater are separated, and the treated clean water overflows from the overflow hole of the water outlet pipeline.

Further, the iron-supported solid catalyst of the present invention uses granular activated carbon, brick particles or quartz sand with particle diameters of 2 to 4 mm as the carrier, and the ^FeSO ₄ solution is prepared by impregnation calcination or co-precipitation method. In the above-mentioned carrier, the Fe ²⁺ loading amount is controlled to be 5-10%, which is the iron-supported solid catalyst.

Generally, the flow rate when iron filings are blown into the reactor through the FeSO ₄ dosing pipeline 41 before the reaction starts can be determined according to the flow rate of the pump, and the iron filings only need to be injected into the reactor.

Usually, the FeSO ₄ aqueous solution and/or the iron-supported solid catalyst solution play a role in catalyzing the reaction, and the calculated amount can be passed into the reactor, and the flow rate is recommended to be 0.1-5 mL/min.

Compared with the homogeneous Fenton system, the heterogeneous circulating fluidized bed Fenton system of the present invention has the following advantages:

1. Due to its larger specific surface area, the solid catalyst can provide more active sites, so that more iron can be loaded on it, thereby improving the reaction efficiency, and due to the improvement of the charge transfer efficiency, the use of hydrogen peroxide is significantly reduced , which can well promote the homogeneous reaction.

2. The internal circulation process in the fluidized bed reactor improves the solid-liquid mass transfer efficiency. In the fluidized bed reaction zone, the solid catalyst and iron filings are pushed up when the liquid flows upward, and the existence of a single baffle makes the density difference between the two sides, so that the liquid flows to the other side, so that the solid-liquid circulates directly in the reactor, improving the The mass transfer efficiency between solid and liquid is improved, which also significantly improves the reaction efficiency of heterophase Fenton.

3. Providing a light source in the reaction zone can play a synergistic effect on the Fenton reaction. Due to the relatively narrow band gap of iron, visible light can excite electron transitions on iron atoms to form electron-hole pairs. The strong oxidizing property can improve the electron transfer efficiency and play a good role in boosting the Fenton reaction.

Description of drawings

Figure 1 is a process flow diagram of the three-phase single-baffle inner-circulating Fenton fluidized bed for the treatment of organic wastewater.

In Figure 1, 1-fluidized bed reactor tower, 11-uniform water distributor, 12-solid-liquid separator, 13-light source device, 14-single baffle, 15-circulation interface, 16-water inlet, 17 - Feed port, 2-circulation device, 21-circulation pump, 3-water inlet pipeline, 31-connecting pipeline, 4-dosing pipeline, 41-FeSO ₄ -dosing pipeline, 42-hydrogen peroxide dosing pipeline , 5-water outlet pipeline, 61-pressurizing pump, 62-air pump, 63-FeSO ₄ -dosing pipeline pressurizing pump, 64-hydrogen peroxide dosing pipeline pressurizing pump, 7-flow meter, 8-stop valve , 9 - intake pipe. There are several in the flowmeter and globe valve diagrams, only one of which is marked.

Detailed ways

The present invention will be further described below with reference to the specific accompanying drawing 1 and the embodiments, but the protection scope of the present invention is not limited to this.

The present invention adopts the three-phase single baffle inner loop Fenton fluidized bed treatment device shown in FIG. 1 to realize the treatment of waste water, including the fluidized bed reactor tower body 1 (diameter 15cm, height 100cm), circulation pipeline 2, Water inlet pipe 3, dosing pipe 4, water outlet pipe 5, air inlet pipe 9. The top of the tower body of the fluidized bed reactor is open, and the bottom of the tower body is provided with a uniform water distributor 11. The uniform water distributor 11 is in the shape of a round cake, and there are water outlet holes evenly distributed on the surface, with 30-50 uniform openings. The aperture is 2-10mm. A solid-liquid separator 12 is installed at 2/3 of the height of the tower body. The side wall of the tower body above the solid-liquid separator 12 is provided with a circulation interface 15. The height of the circulation interface is 2/3 of the height of the tower body; it is located 10cm above the circulation interface. The area is the settlement area, and the water outlet pipeline 5 is located on the side wall of the tower body in the settlement area.

The lower part of the solid-liquid separator is the fluidized bed Fenton reaction zone, a light source device 13 is arranged on one side of the Fenton reaction zone, the light source device is an ultraviolet light source, and the height of the light source device is 1/3 of the height of the tower body; There is also a vertical single baffle 14 in the zone, one side of the single baffle is fixed on the side wall of the column body of the fluidized bed reactor, and the plane where the single baffle 14 is located falls on the The said plane is perpendicular to 2/3 of the diameter of the circular section passing through the central axis of the column body of the fluidized bed reactor, and the length and width are respectively 15cm and 10cm; The circulation interface 15 provided on the side wall above the solid-liquid separator of the reactor tower body is connected, and the other end is connected with the water inlet 16 located at the bottom of the fluidized bed reactor tower body, and the circulation pipeline 2 is arranged in the middle There is a connecting pipeline 31 provided with a cut-off valve 8, the connecting pipeline is communicated with the water inlet pipeline 3, and a pressurizing pump 61 is arranged between the connecting pipeline and the water inlet pipeline; the circulation pipeline 2 is close to the water inlet. A circulating pump 21 is arranged between the connecting pipeline;

The fluidized bed Fenton reaction zone is provided with a feed port 17 near the side wall of the tower body of the uniform water distributor; the dosing pipeline 4 includes a FeSO ₄ dosing pipeline 41 and a hydrogen peroxide dosing pipeline 42, so The FeSO ₄ dosing pipeline and the hydrogen peroxide dosing pipeline are respectively connected to the feeding port through the pressurizing pumps 63 and 64 , and the air inlet pipe is also connected to the feeding port 17 through the air pump 62 . In order to monitor the feeding situation of each pipeline, the FeSO ₄ dosing pipeline, the hydrogen peroxide dosing pipeline, the connecting pipeline and the intake pipe are all equipped with corresponding flow meters, and the circulation device, the dosing pipeline and the water outlet pipeline are all provided with cut-off valve 8.

Example 1

The petrochemical wastewater is treated with a three-phase single-baffle inner loop Fenton fluidized bed, and injected into the reactor through a wastewater pump (ie, a pressurized pump connected to the pipeline), and the COD of the wastewater is 408 mg/L after dilution. The pH of the wastewater is adjusted to 3, the volume of the diluted wastewater is 10L, and the flow rate of the wastewater is controlled to be 20mL/min. The required volume of hydrogen peroxide in the pharmaceutical storage tank is 100 mL (concentration is 0.1 mol/L), and the required volume of FeSO ₄ ·7H ₂ O aqueous solution is 20 mL (concentration is 0.1 mol/L). Check the opening and closing of each valve before the Fenton fluidized bed starts to run. When it is confirmed to be correct, turn on the waste water pump and blow 50g iron filings into the reactor through the FeSO ₄ dosing pipeline. When the amount of waste water is close to the solid-liquid separator, close the inlet and outlet. The water pipeline and the circulating pump continue to work, open the air intake pipe, at this time the blown air pushes the waste water to circulate in the reaction zone, and the air flow is kept at 200mL/min by controlling the flow meter, and the liquid level reaches above the solid-liquid separator and is submerged. After the circulation interface, part of the waste water re-enters the reactor through the circulation pipeline. At this time, the water inlet pipeline (flow rate 20mL/min) and the dosing pipeline are opened, and the hydrogen peroxide and FeSO ₄ are injected into the reactor through their respective pressure pumps. Control the flow to 5mL/min and 5mL/min respectively, and turn on the light source at the same time. After continuous treatment for 1 hour, the effluent from the upper part of the solid-liquid separator was gradually clear, the COD of the effluent was measured to drop to 43 mg/L, and the chromaticity dropped to 0.7 times, meeting the national discharge standard.

Example 2

The petrochemical wastewater is treated with a three-phase single-baffle internal circulating Fenton fluidized bed. The COD of the wastewater is 632 mg/L after dilution, and the chromaticity is 78 times. The pH of the wastewater is adjusted to 4, and the volume of the diluted wastewater is 10L. Control The wastewater flow rate was 30 mL/min. The required volume of hydrogen peroxide in the pharmaceutical storage tank is 500 mL (concentration is 0.1 mol/L), and the required volume of FeSO ₄ ·7H ₂ O aqueous solution is 50 mL (concentration 0.1 mol/L). Check the opening and closing of each valve before the Fenton fluidized bed starts to run. When it is confirmed to be correct, turn on the waste water pump and blow 70g iron filings into the reactor through the FeSO ₄ dosing pipeline. When the amount of waste water is close to the solid-liquid separator, close the inlet and outlet. The water pipeline and the circulating pump continue to work, open the air intake pipe, at this time, the blown air pushes the waste water to circulate in the reaction zone, and the air flow is maintained at 400mL/min by controlling the flow meter, and the liquid level reaches the solid-liquid separator and submerges it. After the circulation interface, part of the waste water re-enters the reactor through the circulation pipeline. At this time, the water inlet pipeline and the dosing pipeline are opened, and hydrogen peroxide and FeSO ₄ are injected into the reactor through their respective pressure pumps, and the flow rates are controlled to 8mL/ min and 6mL/min, while turning on the light source. After continuous treatment for 2 hours, the effluent from the upper part of the solid-liquid separator was gradually clear, the COD of the effluent was measured to drop to 65mg/L, and the chromaticity dropped to 4 times, meeting the national discharge standard.

Example 3

The petrochemical wastewater is treated with a three-phase single-baffle inner circulating Fenton fluidized bed. The COD of the wastewater is 856 mg/L after dilution, and the chromaticity is 102 times. The pH of the wastewater is adjusted to 4, and the volume of the diluted wastewater is 10L. Control The wastewater flow rate was 50 mL/min. The required volume of hydrogen peroxide in the pharmaceutical storage tank is 1000mL (concentration is 0.1mol/L), and the required volume of FeSO ₄ ·7H ₂ O aqueous solution is 50mL (concentration is 0.1mol/L). Check the opening and closing of each valve before the Fenton fluidized bed starts to run. After confirming that it is correct, turn on the waste water pump and blow 100g of iron filings into the reactor through the FeSO ₄ dosing pipeline. When the amount of waste water is close to the solid-liquid separator, close the inlet and outlet. The water pipeline and the circulating pump continue to work, open the air intake pipe, at this time, the blown air pushes the waste water to circulate in the reaction zone, and the air flow is kept at 1000mL/min by controlling the flow meter, and the liquid level reaches the solid-liquid separator and submerges it. After the circulation interface, part of the waste water re-enters the reactor through the circulation pipeline. At this time, the water inlet pipeline and the dosing pipeline are opened, and hydrogen peroxide and FeSO ₄ are injected into the reactor through their respective pressure pumps, and the flow rates are controlled to 10mL/ min and 5mL/min, while turning on the light source. After 2 hours of continuous treatment, the effluent from the upper part of the solid-liquid separator was gradually clear, the COD of the effluent was measured to drop to 102 mg/L, and the chromaticity dropped to 9 times, meeting the national discharge standard.

Claims (8)

1. The utility model provides a method for utilize fragrant fluidized bed processing apparatus of interior circulation of three-phase single baffle to handle waste water, fragrant fluidized bed processing apparatus of interior circulation of three-phase single baffle includes fluidized bed reactor tower body (1), circulation pipeline (2), water inlet pipe (3), adds medicine pipeline (4), goes out water pipeline (5), intake pipe (9), its characterized in that:

the top of the fluidized bed reactor tower body (1) is open, a water outlet pipeline (5) is arranged on the side wall of the fluidized bed reactor tower body close to the top opening, a uniform water distributor (11) is arranged at the bottom of the fluidized bed reactor tower body and is communicated with a water inlet (16) positioned at the bottom of the fluidized bed reactor tower body, a solid-liquid separator (12) is horizontally arranged above the tower body at a height of 1/2, and a circulating interface (15) is arranged on the side wall of the fluidized bed reactor tower body above the solid-liquid separator (12) and close to the solid-liquid separator (12); the fluidized bed reactor body (1) is divided into an upper part and a lower part by the solid-liquid separator (12), and the water outlet pipeline (5) is positioned on the side wall of the fluidized bed reactor body above the circulating interface (15);

a fluidized bed Fenton reaction zone is arranged below the solid-liquid separator (12), a light source device (13) is arranged on one side of the Fenton reaction zone, a vertical single baffle (14) is further arranged in the reaction zone, and one side edge of the single baffle (14) is fixed on the side wall of the fluidized bed reactor tower body (1); one end of the circulating pipeline (2) is connected with a circulating interface (15) arranged on the side wall above the fluidized bed reactor tower body solid-liquid separator, the other end of the circulating pipeline is communicated with a water inlet (16) positioned at the bottom of the tower body, a connecting pipeline (31) provided with a stop valve (8) is arranged in the middle of the circulating pipeline (2), the connecting pipeline (31) is communicated with a water inlet pipeline (3), and a third pressure pump (61) is arranged between the connecting pipeline (31) and the water inlet pipeline (3); a circulating pump (21) is arranged between the position of the circulating pipeline (2) close to the water inlet (16) and the connecting pipeline;

a feed inlet (17) is arranged at the position of the Fenton reaction zone of the fluidized bed, which is close to the side wall of the tower body of the uniform water distributor; the drug adding pipeline (4) comprises FeSO₄A dosing pipeline (41) and a hydrogen peroxide dosing pipeline (42), the FeSO₄The dosing pipeline and the hydrogen peroxide dosing pipeline are respectively connected with the feeding hole (17) through a corresponding first pressurizing pump (63) and a corresponding second pressurizing pump (64), and the air inlet pipe (9) is also communicated with the feeding hole (17) through an air pump (62); the method comprises the following steps:

(1) diluting wastewater to be treated to 400-900 mg/L of COD, adjusting the pH to 3-4, sequentially passing through a water inlet pipeline (3), a connecting pipeline (31) and a circulating pump (21) and injecting the wastewater into a fluidized bed reactor, and controlling the flow of the wastewater to be 20-50 mL/min through a flow meter on the connecting pipeline; by FeSO before the start of the reaction₄Feeding scrap iron accounting for 5-10 wt% of the mass of the diluted wastewater into the reactor through a dosing pipeline (41);

(2) when the liquid level of the wastewater rises to approach a solid-liquid separator (12), a light source device (13) is turned on, a water inlet pipeline (3) is turned off, a circulating pump (21) continues to work, an air inlet pipe (9) is opened, the blown air pushes the wastewater to circularly flow in a Fenton reaction zone of the fluidized bed, and the air flow is kept at 200-1000 mL/min by controlling a flow meter;

(3) after the liquid level reaches the solid-liquid separator (12) and submerges the circulating interface (15), part of the waste liquid is dischargedWater re-enters the reactor through the circulating pipeline (2), at the moment, the water inlet pipeline (3) and the medicine adding pipeline (4) are opened, and the prepared H is₂O₂The aqueous solution is blown into the reactor from a hydrogen peroxide feeding pipeline (42), the flow is controlled to be 5-10 mL/min, and H is blown into the fluidized bed reactor₂O₂The mass concentration of the substance(s) is 0.001-0.01 mol/L;

simultaneously, the prepared FeSO₄Aqueous and/or iron-supported solid catalyst solutions from FeSO₄A medicine adding pipeline (41) is blown into the reactor, and the prepared H₂O₂H in aqueous solution₂O₂With prepared FeSO₄Fe in aqueous solution and/or iron-supported solid catalyst solution²⁺The mass ratio of (A) to (B) is 5-20: 1; the iron-supported solid catalyst is Fe²⁺A solid catalyst with a load of 5-10%;

at the moment, the water discharged by the uniform water distributor (11) keeps a certain rising speed, liquid in the fluidized bed reactor circularly flows on two sides of a single baffle plate (14), and the iron-loaded solid catalyst and the iron filings are in a fluidized state; fe²⁺And H₂O₂Fe generated by oxidation reaction³⁺Adsorbing the iron-loaded solid catalyst and the iron filings on the surfaces in a crystallization precipitation mode;

(4) after passing through the solid-liquid separator, scrap iron and the iron-loaded solid catalyst in the wastewater are separated, and the treated clean water overflows from an overflow hole of the water outlet pipeline.

2. The method for treating wastewater using a three-phase single-baffle internal-circulation fenton fluidized bed treatment apparatus according to claim 1, wherein the single baffle (14) is located on a plane falling at 2/3 which is a diameter of a circular section perpendicular to the plane passing through a central axis of the fluidized bed reactor tower (1).

3. The method for treating wastewater using a three-phase single-baffle internal circulation fenton fluidized bed treatment apparatus according to claim 1, wherein: the FeSO₄The dosing pipeline (41), the hydrogen peroxide dosing pipeline (42), the connecting pipeline (31) and the air inlet pipe (9) are all provided with the same phaseThe flow meter is used.

4. The method for treating wastewater using a three-phase single-baffle internal circulation fenton fluidized bed treatment apparatus according to claim 1, wherein: the circulating pipeline (2), the medicine adding pipeline (4), the water outlet pipeline (5) and the air inlet pipe (9) are all provided with stop valves.

5. The method for treating wastewater using a three-phase single-baffle internal circulation fenton fluidized bed treatment apparatus according to claim 1, wherein: the chemical feeding pipeline (4) and the water outlet pipeline (5) are both provided with filter screens, and the mesh number of the filter screens is 200-300 meshes.

6. The method for treating wastewater using a three-phase single-baffle internal circulation fenton fluidized bed treatment apparatus according to claim 1, wherein: the uniform water distributor (11) is in a round cake shape, and water outlet holes are uniformly distributed on the surface of the uniform water distributor (11).

7. The method for treating wastewater using a three-phase single-baffle internal circulation fenton fluidized bed treatment apparatus according to claim 6, wherein: the surface of the round cake is uniformly provided with 30-50 holes, and the diameter of each hole is 2-10 mm.

8. The method for treating wastewater using a three-phase single-baffle internal circulation fenton fluidized bed treatment apparatus according to claim 1, wherein: the iron-loaded solid catalyst takes granular active carbon, brick grains or quartz sand with the grain size of 2-4 mm as a carrier, and FeSO is prepared₄The solution is prepared by impregnating, calcining or coprecipitating Fe²⁺Loading into the carrier to control Fe²⁺The loading amount is 5-10%, and the iron-loaded solid catalyst is obtained.

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