Novel advanced oxidation reaction device for treating nitrobenzene wastewater

Abstract

The utility model discloses a novel advanced oxidation reaction device for treating nitrobenzene wastewater, which comprises a reaction tank, a guide cylinder arranged at the center of the reaction tank, iron-carbon filler filled in the guide cylinder, and a grating plate arranged at the bottom of the guide cylinder; ultraviolet lamp groups which are vertically mounted are uniformly arranged between the guide cylinder and the reaction tank, the ultraviolet lamp groups are connected with an external control system, and a water inlet pipeline is arranged on the guide cylinder; a water inlet is formed outside the upper edge of the reaction tank and is connected with the guide cylinder through a water inlet pipeline; a water outlet groove and a water outlet weir plate are arranged along the periphery in the upper edge of the reaction tank; a water outlet is formed in the water outlet groove; aerators are uniformly arranged at the bottom of the reaction tank; a sludge discharge pipe is arranged at the bottom of the reaction tank; and a pH analyzer, an ORP online analyzer and a dosing pipeline are arranged at the upper part of the reaction tank. When the device is used for treating nitrobenzene wastewater, the dosage of a Fenton reagent can be reduced, secondary pollution is reduced, hardening and passivation of iron-carbon filler are avoided, automatic control can be realized, and labor is reduced.

Description

Technical Field

[0001] This utility model relates to the field of industrial wastewater treatment technology, specifically to a novel advanced oxidation reaction device for treating nitrobenzene wastewater. Background Technology

[0002] Nitrobenzene-based wastewater is industrial wastewater containing nitrobenzene and its derivatives (such as nitrobenzene, dinitrobenzene, and nitrobenzene), mainly originating from industries such as dyes, pesticides, explosives, pharmaceuticals, and chemicals. This type of wastewater is characterized by high toxicity, reluctance to degrade, and carcinogenicity, posing a significant threat to the environment and human health, and must undergo strict treatment before discharge.

[0003] The strong oxidizing properties of nitro groups inhibit the activity of biological enzymes and hinder biodegradation pathways. There are few microorganisms in nature that can directly use nitrobenzene as a carbon and energy source, requiring long-term domestication. Due to the conjugated π-bond system and high bond energy of the benzene ring, and the electron-withdrawing effect of the nitro groups on the benzene ring, especially at the ortho and para positions, electrophilic attacks (such as ·OH radical oxidation) become more difficult. Therefore, due to their stable chemical structure and physicochemical properties, conventional chemical and biological oxidation techniques are insufficient to directly break the benzene ring, requiring relatively high energy for destruction.

[0004] Commonly used treatment processes employ iron-carbon micro-electrolysis technology to reduce nitrobenzene to aniline, followed by Fenton oxidation, utilizing the galvanic cell effect generated by iron and carbon for synergistic degradation. However, iron-carbon processes are prone to caking and passivation after prolonged operation, thus reducing the wastewater treatment efficiency. Traditional Fenton oxidation methods require large amounts of oxidants and catalysts, resulting in high operating costs and excessive sludge production, making them uneconomical. Utility Model Content

[0005] To address the shortcomings of existing technologies, this invention provides a novel advanced oxidation reaction device for treating nitrobenzene wastewater. It features high treatment efficiency, low operating costs, solves the problems of iron and carbon caking and passivation, reduces Fenton dosage, saves costs, and reduces secondary pollution.

[0006] This utility model provides a novel advanced oxidation reaction device for treating nitrobenzene wastewater. The device includes: a reaction tank, a flow guide cylinder at the center of the reaction tank, iron-carbon packing material inside the flow guide cylinder, and a grid plate at the bottom of the flow guide cylinder for supporting the iron-carbon packing material; vertically installed ultraviolet lamps are evenly arranged between the flow guide cylinder and the reaction tank, the ultraviolet lamps are connected to an external control system, and a water inlet pipeline is provided on the flow guide cylinder.

[0007] The reaction tank is provided with a water inlet on the outer edge of the upper part of the water inlet, which is connected to the guide tube through the water inlet pipeline;

[0008] The upper edge of the reaction tank is provided with a water outlet trough along the perimeter. An adjustable-height water outlet weir plate is vertically provided on the side of the water outlet trough near the guide tube. A water outlet is provided on the outside of the reaction tank near the bottom of the water outlet trough.

[0009] Aerator groups are evenly arranged at the bottom of the reaction tank. The aerator groups are connected by air pipelines to form a loop. The aerator groups are connected to an external fan.

[0010] The bottom of the reaction tank is equipped with a sludge discharge pipe;

[0011] The upper part of the reaction tank is equipped with a pH analyzer and an online ORP analyzer, as well as a dosing pipeline. The dosing pipeline is connected to the acid dosing pump and the oxidant dosing pump. The pH analyzer is electrically connected to the acid dosing pump, and the online ORP analyzer is electrically connected to the oxidant dosing pump.

[0012] Preferably, the bottom of the guide tube is fixed to the bottom of the reaction tank by a detachable bracket, and the side wall of the guide tube is fixed to the side wall of the reaction tank by a support mechanism and bolts;

[0013] The guide tube is equipped with lifting lugs.

[0014] Preferably, the reaction tank and the guide tube are made of corrosion-resistant carbon steel or fiberglass.

[0015] Preferably, the iron-carbon mass ratio of the iron-carbon filler is 2:1.

[0016] Preferably, the ultraviolet lamp assembly is equipped with a waterproof quartz sleeve, an automatic cleaning device, a matching ballast, and an ultraviolet intensity sensor. The external control system is an automated control system, which is electrically connected to the automatic cleaning device, the matching ballast, and the ultraviolet intensity sensor.

[0017] Preferably, the ultraviolet lamp tube of the ultraviolet lamp assembly is a low-pressure mercury lamp.

[0018] Preferably, the aerator group is a swirl aerator, a jet aerator, or a surface aerator.

[0019] Preferably, the air pipeline of the aerator group is connected to an external fan, and the frequency converter of the fan can be adjusted to control the air-to-water ratio to 20:1 to 40:1.

[0020] Preferably, the side wall of the outlet trough where the outlet weir plate is installed has multiple bolt holes along the longitudinal direction, and the outlet weir plate is fixed to the outlet trough through the multiple bolt holes and expansion bolts.

[0021] Preferably, the mud discharge pipe is a perforated pipe with holes facing downwards at a 45° angle and arranged in a crisscross pattern, with a spacing of 0.3 to 0.8 m between the holes.

[0022] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0023] 1. This utility model provides an advanced oxidation treatment device for efficiently treating high-concentration nitrobenzene wastewater. It features a special reactor structure with a central guide tube, central water inlet, and peripheral water outlet. The layout is reasonable, saves space, and promotes full contact between wastewater and iron-carbon packing material. This reduces nitrobenzene substances to aniline. The generated Fe2+ ions react rapidly with the oxidant under the enhanced excitation of ultraviolet light, decomposing organic matter. It also has a synergistic effect of flocculation, adsorption, and bridging, making the removal of organic matter more thorough, efficient, and complete.

[0024] 2. This invention utilizes Fe2+ ions generated by iron-carbon internal electrolysis as a catalyst for Fenton, and combines them with electrons and holes generated by ultraviolet light excitation to promote the generation of active substances ·OH with strong oxidizing properties, thereby improving the oxidation rate and the removal rate of organic matter. Compared with the traditional Fenton reaction, it can reduce the amount of reagents added by more than 50%, reduce the amount of sludge produced by 50% to 80%, and reduce the amount of salt introduced by more than 70%, while achieving a saving of 30% to 50% in operating costs.

[0025] 3. The guide tube provided by this utility model contains iron-carbon packing material. The scouring of the aerator can slow down the caking and passivation of the packing material and promote rapid reaction. The guide tube is fixed by a bracket and can be disassembled. It is easy to install and disassemble, and facilitates the replacement, flushing and maintenance of the packing material.

[0026] 4. This utility model utilizes online analysis instruments to control the dosage of chemicals, enabling automatic adjustment of the dosage according to changes in water quality. This improves the intelligent operation performance, making it convenient, quick, labor-saving, and easy to promote. Attached Figure Description

[0027] Figure 1 A schematic diagram of the structure of a novel advanced oxidation reactor for treating nitrobenzene wastewater provided by this utility model;

[0028] Figure 2 This is a top view schematic diagram of a novel advanced oxidation reaction device for treating nitrobenzene wastewater according to the present invention.

[0029] In the attached diagram, 1. reaction tank, 2. guide tube, 3. inlet, 4. iron-carbon packing, 5. support mechanism, 6. ultraviolet lamp assembly, 7. aerator assembly, 8. effluent tank, 9. effluent weir plate, 10. bracket, 11. sludge discharge pipe, 12. grid plate, 13. air pipeline, 14. lifting lug, 15. outlet. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0031] The present invention will now be described in further detail with reference to the accompanying drawings:

[0032] This utility model provides a novel advanced oxidation reaction device for treating nitrobenzene wastewater. The device includes: a reaction tank 1, a guide cylinder 2 at the center of the reaction tank 1, the guide cylinder 2 being filled with iron-carbon packing material 4, and a grid plate 12 at the bottom of the guide cylinder 2 to support the iron-carbon packing material 4 and prevent it from falling off; vertically installed ultraviolet lamp groups 6 are evenly arranged between the guide cylinder 2 and the reaction tank 1, and the ultraviolet lamp groups 6 are connected to an external control system; a water inlet pipe is provided on the guide cylinder 2; a water inlet 3 is provided on the outer side of the upper edge of the reaction tank 1, and the water inlet 3 is connected to the guide cylinder 2 through the water inlet pipe; and a water outlet is provided along the circumference of the inner side of the upper edge of the reaction tank 1. The reaction tank 1 has a vertically adjustable weir plate 9 near the guide tube 2 in tank 8. An outlet 15 is located on the outside of the reaction tank 1 near the bottom of tank 8. Aerator groups 7 are evenly arranged at the bottom of the reaction tank 1, connected by air lines 13 to form a loop, and connected to an external blower. A sludge discharge pipe 11 is located at the bottom of the reaction tank 1. A pH analyzer and an online ORP analyzer, as well as dosing lines, are located at the top of the reaction tank 1. These dosing lines are connected to acid dosing pumps and oxidant dosing pumps. The pH analyzer is electrically connected to the acid dosing pump, and the online ORP analyzer is electrically connected to the oxidant dosing pump. The pH analyzer and acid dosing pump are interlocked to automatically control the acid dosage; the online ORP analyzer and oxidant dosing pump are interlocked to automatically control the dosing amount.

[0033] In this embodiment of the utility model, the bottom of the guide tube 2 is fixed to the bottom of the reaction tank 1 by a detachable bracket 10, and the side wall of the guide tube 2 is fixed to the side wall of the reaction tank 1 by a support mechanism 5 and bolts; the guide tube 2 is provided with a lifting lug 14.

[0034] In this embodiment of the invention, the reaction tank 1 and the guide tube 2 are made of corrosion-resistant carbon steel and fiberglass, ensuring long-term use under acidic conditions.

[0035] In this embodiment of the invention, the iron-carbon mass ratio of the iron-carbon filler 4 is 2:1. To provide more energy for the galvanic cell and improve reaction efficiency, a filler with a higher iron-carbon mass ratio is preferred. However, to avoid an excessively high iron-carbon mass ratio leading to predominance of dissolved iron under acidic conditions, a 2:1 iron-carbon mass ratio is preferred.

[0036] In this embodiment of the invention, the UV lamp assembly 6 is externally equipped with a waterproof quartz sleeve, an automatic cleaning device, a matching ballast, and a UV intensity sensor. The external control system is an automated control system, electrically connected to the automatic cleaning device, the matching ballast, and the UV intensity sensor. The waterproof quartz sleeve protects the UV lamp from water corrosion, while the high transmittance of quartz ensures effective UV emission. The automatic cleaning device periodically removes dirt from the surface of the UV lamp tube using mechanical or pneumatic methods, ensuring UV transmittance and maintaining the disinfection effect. The matching ballast stabilizes the operating current and voltage of the UV lamp, enabling it to emit light normally and stably, extending its lifespan. The automated control system enables automated control of the UV lamp assembly, such as timed switching and automatic adjustment of UV intensity based on set parameters, facilitating operation and management. The UV intensity sensor monitors the UV intensity in real time and feeds the signal back to the automated control system, allowing the system to adjust the operating status of the UV lamp according to actual conditions, ensuring the UV intensity remains within an effective range.

[0037] In this embodiment of the present invention, the ultraviolet lamp tube of the ultraviolet lamp group 6 is a low-pressure mercury lamp.

[0038] In this embodiment of the invention, the aerator group 7 adopts a swirl aerator, jet aerator, or surface aerator. The air pipeline 13 of the aerator group 7 is connected to an external fan, and the frequency converter of the fan can be adjusted to control the air-to-water ratio of 20:1 to 40:1. The aerator group 7 is evenly distributed at the bottom of the reaction tank 1, with the aerators arranged in a ring and the air pipeline forming a loop. The aerators are preferably swirl aerators, jet aerators, or surface aerators to prevent clogging. The aerators have a large scouring force, which can prevent the iron and carbon packing from caking and is conducive to removing the passivation film on the surface of the packing, so that the packing maintains a high surface activity. In addition, the increased water flow turbulence can make the wastewater mix quickly and evenly, and the reaction is complete and efficient.

[0039] In this embodiment of the invention, the side wall of the water outlet tank 8 on which the water outlet weir plate 9 is installed has multiple bolt holes along the longitudinal direction. The water outlet weir plate 9 is fixed to the water outlet tank 8 through the multiple bolt holes and expansion bolts. By adjusting the water outlet height at different fixing positions, the residence time of the reaction can be controlled, allowing for flexible adjustment and strong applicability.

[0040] In this embodiment of the utility model, the mud discharge pipe 11 adopts a perforated pipe for mud discharge, with the holes facing downward at 45° and arranged in a crisscross pattern, and the spacing between the holes is 0.3 to 0.8 m.

[0041] See Figure 1 , Figure 2The reaction device of this utility model mainly includes: a reaction tank 1, a guide cylinder 2, iron-carbon packing material 4, an ultraviolet lamp assembly 6, and an aerator 7. Nitrobenzene wastewater enters the connected guide cylinder 2 through the inlet pipe via the inlet 3; the guide cylinder 2 is filled with iron-carbon packing material 4, and a grid plate 12 is placed at the lower part of the guide cylinder 2, with appropriate gaps selected to support the packing material 4 to prevent it from falling; the guide cylinder 2 is fixed in the reaction tank 1 by a bracket 10, and a support mechanism 5 is welded and fixed by bolts; the ultraviolet lamp assembly 6 is evenly distributed around the guide cylinder 2, and the ultraviolet lamp assembly 6 is vertically arranged between the guide cylinder 2 and the reaction tank 1; an aerator assembly 7 is installed at the bottom of the reaction tank 1, and multiple aerators are connected through an air pipe 13 to form a loop; a perforated sludge discharge pipe 11 is provided at the bottom of the reaction tank 1, and an outlet trough 8 is provided along the circumference of the upper part of the reaction tank 1, with an outlet weir plate 9 connected to the outlet trough 8 by bolts; the treated wastewater is discharged from the outlet trough 8 through the outlet 15. In addition, the bolts fixing the guide tube 2 can be removed, and the crane can lift the guide tube 2 through the lifting lug 14 to replace or maintain the iron-carbon filler 4.

[0042] Example 1:

[0043] The reaction apparatus provided in Embodiment 1 of this utility model has the following structure and implementation process:

[0044] (1) Nitrobenzene-containing wastewater is pumped into polyurea-resistant carbon steel reaction tank 1 through inlet 3. The pH of the wastewater is controlled at 3-4 through a smart control system, which is linked to a pH meter and a concentrated sulfuric acid dosing pump.

[0045] (2) Wastewater enters the guide tube 2 through the inlet 3 and the inlet pipeline, and reacts fully with the iron-carbon packing 4. The bottom of the guide tube 2 is fixed to the bottom of the reaction tank 1 by the bracket 10, and fixed to the side wall of the reaction tank 1 by the support mechanism 5 and bolts. The mass ratio of iron-carbon packing 4 is about 2:1, which makes nitrobenzene organic matter efficiently converted into easily degradable aniline.

[0046] (3) The aerator group 7 at the bottom of the reaction tank 1 adopts a vortex aerator. Turning on the aerator makes the wastewater mix evenly and washes the packing, avoiding the packing from becoming caking and passivated; the air-water ratio is controlled at 20:1; after the wastewater passes through the guide tube 2, Fe2+ ions dissolve and flow into the reaction tank 1 from the bottom of the guide tube 2 through the grid plate 12.

[0047] (4) A UV lamp group 6 is evenly arranged between the reaction tank 1 and the guide tube 2. When the UV lamp group 6 is turned on, it stimulates the added oxidant to generate more hydroxyl radicals, which accelerates the decomposition rate of organic matter, reduces the amount of Fenton reagent, and saves costs. The amount of oxidant added is controlled by the ORP online analyzer.

[0048] (5) A water outlet trough 8 is welded to the upper part of the reaction tank 1. A water outlet weir plate 9 is provided on the side of the water outlet trough 8 near the guide tube 2. It is fixedly connected to the water outlet trough 8 by bolts. The height of the water outlet weir plate 9 can be adjusted to control the reaction time, ensure that the Fenton reaction is sufficient and the nitrobenzene removal rate is high. The qualified effluent flows into the water outlet trough 8 through the water outlet weir plate 9 and is discharged from the reaction tank 1 through the water outlet 15.

[0049] (6) In order to prevent sludge from accumulating in the reaction device, a perforated sludge discharge pipe 11 is installed at the bottom of the reaction tank 1.

[0050] (7) The crane lifts the guide cylinder 2 through the lifting lug 14 and replaces and flushes the iron-carbon packing 4.

[0051] Example 2:

[0052] Taking the treatment of wastewater from the production of toluene diisocyanate as an example:

[0053] Analysis of the wastewater containing nitrobenzene showed that the influent nitrobenzene content was 200 mg / L and the COD concentration was approximately 5000 mg / L.

[0054] The reaction tank 1 is made of fiberglass. The guide tube 2 is filled with iron-carbon packing material 4 at a mass ratio of 2:1. A jet aerator 7 and a perforated sludge discharge pipe 11 are installed at the bottom of the reaction tank 1. Eight sets of ultraviolet lamps are set up. The pH of the nitrobenzene wastewater is adjusted to about 3, and the gas-water ratio is controlled at 25:1. Hydrogen peroxide is added as an oxidant, and the height of the effluent weir plate 9 is adjusted. The wastewater is controlled to react in the reaction device for 1 hour. The effluent from the reaction flows into the effluent tank 8 through the effluent weir plate 9 and is discharged from the reaction device of this utility model through the effluent outlet 15.

[0055] Analysis of the effluent showed that the nitrobenzene content was approximately 10 mg / L and the COD concentration was approximately 300 mg / L. The biodegradability of this nitrobenzene wastewater was significantly improved.

[0056] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A novel advanced oxidation reactor for treating nitrobenzene wastewater, characterized in that, The device includes: a reaction tank (1), a flow guide cylinder (2) is set in the center of the reaction tank (1), the flow guide cylinder (2) is filled with iron-carbon filler (4), and a grid plate (12) is set at the bottom of the flow guide cylinder (2) to support the iron-carbon filler (4); vertically installed ultraviolet lamp groups (6) are evenly arranged between the flow guide cylinder (2) and the reaction tank (1), the ultraviolet lamp groups (6) are connected to an external control system, and a water inlet pipe is set on the flow guide cylinder (2); The reaction tank (1) has a water inlet (3) on the outer edge of its upper part, and the water inlet (3) is connected to the guide tube (2) through the water inlet pipeline; The reaction tank (1) has a water outlet trough (8) along its circumference at the upper edge. The water outlet trough (8) has an adjustable height water outlet weir plate (9) vertically arranged on the side near the guide tube (2). The reaction tank (1) has an outlet (15) at the bottom near the water outlet trough (8). The bottom of the reaction tank (1) is uniformly arranged with aerator groups (7), the aerator groups (7) are connected through air pipelines (13) to form a loop, and the aerator groups (7) are connected to an external fan. The bottom of the reaction tank (1) is equipped with a sludge discharge pipe (11); The upper part of the reaction tank (1) is equipped with a pH analyzer and an online ORP analyzer, as well as a dosing pipeline. The dosing pipeline is connected to the acid dosing pump and the oxidant dosing pump. The pH analyzer is electrically connected to the acid dosing pump, and the online ORP analyzer is electrically connected to the oxidant dosing pump.

2. The apparatus according to claim 1, characterized in that, The bottom of the guide tube (2) is fixed to the bottom of the reaction tank (1) by a detachable bracket (10), and the side wall of the guide tube (2) is fixed to the side wall of the reaction tank (1) by a support mechanism (5) and bolts; The guide tube (2) is provided with a lifting lug (14).

3. The apparatus according to claim 1, characterized in that, The reaction tank (1) and the guide tube (2) are made of corrosion-resistant carbon steel and fiberglass.

4. The apparatus according to claim 1, characterized in that, The iron-carbon mass ratio of the iron-carbon filler (4) is 2:

1.

5. The apparatus according to claim 1, characterized in that, The ultraviolet lamp assembly (6) is equipped with a waterproof quartz sleeve, an automatic cleaning device, a matching ballast, and an ultraviolet intensity sensor. The external control system is an automated control system, which is electrically connected to the automatic cleaning device, the matching ballast, and the ultraviolet intensity sensor.

6. The apparatus according to claim 1, characterized in that, The ultraviolet lamp tube of the ultraviolet lamp assembly (6) is a low-pressure mercury lamp.

7. The apparatus according to claim 1, characterized in that, The aerator group (7) adopts a swirl aerator, jet aerator or surface aerator.

8. The apparatus according to claim 1, characterized in that, The air pipeline (13) of the aerator group (7) is connected to an external fan, and the frequency of the fan can be adjusted to control the air-water ratio to 20:1 to 40:

1.

9. The apparatus according to claim 1, characterized in that, The water outlet trough (8) has multiple bolt holes along its longitudinal direction on the side wall where the water outlet weir plate (9) is installed. The water outlet weir plate (9) is fixed to the water outlet trough (8) through the multiple bolt holes and expansion bolts.

10. The apparatus according to claim 1, characterized in that, The mud discharge pipe (11) adopts a perforated pipe for mud discharge, with the holes facing downward at 45° and arranged in a crisscross pattern, and the spacing between the holes is 0.3 to 0.8 m.

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