A multiphase fenton oxidation device

Abstract

The application discloses a multi-phase Fenton oxidation device. The device comprises a reaction tank, which is divided into six equal-sized areas by partitions into two rows and three columns; wherein the first row of the reaction tank is sequentially provided with an Fe2+ regeneration area, a homogeneous Fenton reaction area and a coagulation and sedimentation area; the second row of the reaction tank is correspondingly provided with an induced Fenton area, a transition area and a water outlet area; wherein the coagulation and sedimentation area, the homogeneous Fenton reaction area, the transition area and the water outlet area are sequentially and communicatively arranged; the coagulation and sedimentation area, the homogeneous Fenton reaction area, the transition area and the water outlet area are sequentially and communicatively arranged. The multi-phase Fenton technology device does not add acid, produces less mud, has less Fe ion escape and has high oxidation efficiency on refractory organic matters, and is an improvement and innovation on the traditional Fenton technology, and has important significance on the expansion and application of the Fenton oxidation technology.

Description

Technical Field

[0001] This invention relates to the field of recalcitrant organic wastewater treatment technology, and particularly to a multiphase Fenton oxidation device. Background Technology

[0002] Currently, Fenton oxidation technology is widely recognized in the industry for advanced oxidation technologies used to treat high-concentration, multi-component organic wastewater. The core of Fenton technology is the use of hydroxyl radicals generated from the decomposition of hydrogen peroxide as the oxidant, and ferrous ions as the catalyst to promote hydrogen peroxide decomposition. Acid is added to adjust the pH to 3-5, triggering the Fenton reaction and generating hydroxyl radicals to oxidize and degrade recalcitrant organic matter. After the reaction, alkali is added to precipitate the ferrous ions. Traditional Fenton technology has a narrow pH range, requires the addition of large amounts of ferrous sulfate catalyst, cannot be reused, and forms polluting iron sludge, easily causing secondary pollution. Based on traditional Fenton technology, heterogeneous Fenton technology has been developed. Heterogeneous Fenton refers to a solid catalyst, leading to the emergence of heterogeneous Fenton fluidized bed technology. The core of this technology is the fluidization of the solid catalyst, utilizing the upward flow of fluid to suspend the catalyst particles in water. Compared to the reaction kinetics of the traditional homogeneous Fenton reaction, the heterogeneous Fenton system exhibits slower reaction rates, lower oxidation efficiency, and the overall catalytic reaction rate is limited by the Fe... 3+ The inefficient reaction with H2O2, Fe in the heterogeneous Fenton system 3+ The high content of Fe limits the overall efficiency of the Fenton reaction. Therefore, how to accelerate the Fe... 3+ Reduced to Fe 2+ This is key to improving the efficiency of heterogeneous Fenton systems.

[0003] Pyrite (FeS2) is one of the most abundant metallic sulfides in nature. It belongs to the cubic crystal system and contains FeS6 octahedra and SS dimers. The S central atoms in pyrite usually appear in pairs, i.e., S2. 2- But S2 2- The SS bond length in Fe is unstable and easily breaks, making it susceptible to oxidation. Under acidic conditions, Fe... 3+ Oxidation of FeS2 to produce Fe 2+ The following reaction occurs: FeS2 + 14Fe 3+ +8H₂O→15Fe 2+ +2SO4 2- +16H + It can accelerate the conversion of Fe 3+ Reduced to Fe 2+This improves the efficiency of the heterogeneous Fenton system. The Fenton-like reaction system using FeS2 as a catalyst exhibits a two-stage degradation kinetic process: an initial slow induction period and a subsequent rapid oxidation period. Researchers believe the induction period is a heterogeneous reaction, while the rapid oxidation period is a homogeneous reaction. The reaction equation is: Fe... 2+ +H₂O₂→Fe 3+ +·OH+OH - This type of Fenton reaction is called a multiphase Fenton system. Using pyrite (FeS2) as a catalyst, a multiphase Fenton oxidation technology has been developed. This multiphase Fenton technology device does not require acid, produces less sludge, and has less Fe ion escape. It has high oxidation efficiency for recalcitrant organic matter and is an improvement and innovation of traditional Fenton technology. It is of great significance for the expansion and application of Fenton oxidation technology. Summary of the Invention

[0004] To overcome the above-mentioned defects, the present invention provides a multiphase Fenton oxidation apparatus.

[0005] To achieve the above objectives, the present invention provides a multiphase Fenton oxidation apparatus, wherein the apparatus includes a reaction tank; the reaction tank is divided into six equal-sized zones in two rows and three columns by partitions;

[0006] The first row of reaction tanks is sequentially equipped with an Fe2+ regeneration zone, a homogeneous Fenton reaction zone, and a coagulation and sedimentation zone.

[0007] The second row of reaction tanks is equipped with an induction Fenton zone, a transition zone, and an effluent zone.

[0008] The coagulation sedimentation zone, homogeneous Fenton reaction zone, transition zone, and effluent zone are sequentially connected.

[0009] The coagulation and sedimentation zone is used for coagulation reactions in recalcitrant organic wastewater to remove most of the colloidal and suspended matter in the wastewater through coagulation and sedimentation.

[0010] In the homogeneous Fenton reaction zone, hydrogen peroxide is added to induce a homogeneous Fenton reaction, which oxidizes and degrades the recalcitrant organic matter in the wastewater discharged from the coagulation and sedimentation zone.

[0011] In the transition zone, OH is added. - It neutralizes the free hydrogen ions in the Fenton reaction product solution after the reaction in the homogeneous Fenton reaction zone;

[0012] Inducing the Fenton zone, FeS2 powder is added to the Fenton reaction product solution to carry out a heterogeneous reaction;

[0013] Fe 2+ Regeneration zone, FeS2 and 14Fe 3+ A reaction occurs, producing 15Fe2+ With 16H + 15Fe 2+ With 16H + The refluxed water enters the homogeneous Fenton reaction zone and undergoes a homogeneous Fenton reaction with the hydrogen peroxide added to the homogeneous Fenton reaction zone, oxidizing and degrading recalcitrant organic matter.

[0014] The product from the Q Fenton reaction in the transition zone enters the effluent zone, and 3 units of OH are added. - Fe in the solution produced by the Fenton reaction 3+ With 3OH - The reaction produces coagulant Fe(OH)3, which is then refluxed to the coagulation and sedimentation zone, while the purified water is discharged from the effluent zone.

[0015] Furthermore, the raw water enters the device from the lower part of the coagulation and sedimentation zone. The coagulation and sedimentation zone utilizes Fe(OH)3 generated in the effluent zone as a coagulant to first treat the raw water by coagulation and sedimentation, reducing the amount of Fe in the subsequent Fenton reaction process. 3+ The amount of loss caused by coagulation reaction.

[0016] Furthermore, 15 units of hydrogen peroxide were added to the lower part of the homogeneous Fenton reaction zone, reacting with Fe... 2+ Fe recirculated in the lower part of the regeneration zone 2+ A homogeneous Fenton reaction occurs, producing ·OH, which oxidizes the recalcitrant organic matter flowing into the middle of the coagulation and sedimentation zone.

[0017] Furthermore, the Fenton reaction product enters the transition zone from the upper part of the homogeneous Fenton reaction zone, and 1 unit of OH is added to the upper part of the transition zone. - The remaining 1 unit of H after neutralizing the Fenton reaction + The Fenton reaction product with a flow rate of 14Q enters the induction Fenton zone from the bottom, and the Fenton reaction product with a flow rate of Q enters the outlet zone from the middle.

[0018] Furthermore, 1 unit of FeS2 powder is added to induce uniform dispersion in the Fenton zone, and the Fe in the Fenton reaction product solution flowing into the transition zone is reacted with the FeS2 powder. 3+ The reaction is thoroughly mixed in Fe 2+ The regeneration zone will regenerate Fe 3+ Completely reduced to Fe 2+ And produce an equivalent of H + The pH is automatically adjusted to 3-5 to create conditions for a homogeneous Fenton reaction, Fe 2+ An intercepting mesh is installed between the regeneration zone and the homogeneous Fenton reaction zone. The mesh aperture is smaller than the FeS2 powder particle size, which effectively reduces the loss of FeS2 powder.

[0019] Furthermore, 3 units of OH were added to the effluent zone. -, and 1 unit of Fe flowing from the transition zone into the outlet zone 3 + The precipitation reaction produces Fe(OH)3 coagulant, which is then returned to the coagulation and sedimentation zone, at which point the effluent is neutral.

[0020] The present invention has the following advantages:

[0021] (1) Compared with the traditional homogeneous Fenton technology, the multiphase Fenton technology and device do not require the addition of acid to adjust the pH. The amount of FeS2 added is 1 / 14 of the amount of FeSO4 added in the traditional homogeneous Fenton technology (calculated as iron). The iron sludge produced is also 1 / 14 of the amount of the traditional homogeneous Fenton technology (calculated as iron). Furthermore, it can be used as a coagulant for resource utilization.

[0022] (2) Compared with traditional anisotropic Fenton technology, this multiphase Fenton technology and device results in less Fe ion escape and FeS2 reduces Fe ion emissions. 3+ Reduced to Fe 2+ It has high efficiency, high recycling rate of Fe-based catalysts, and high catalytic efficiency for H2O2. Therefore, it has high efficiency in oxidizing and degrading recalcitrant organic matter. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the system structure of the present invention.

[0024] The zones are: 1. Coagulation and sedimentation zone; 2. Homogeneous Fenton reaction zone; 3. Transition zone; 4. Induced Fenton zone; 5. Fe2+ regeneration zone; 6. Effluent zone. Detailed Implementation

[0025] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0026] In the description of this invention, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0027] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0028] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0029] Figure 1 The diagram illustrates an embodiment of the multiphase Fenton oxidation device of the present invention. The multiphase Fenton oxidation technology uses pyrite (FeS2) as a catalyst to achieve the Fenton oxidation removal of recalcitrant organic matter in wastewater through a six-cell reaction device. The wastewater containing recalcitrant organic matter flows along the path ①→②→③→⑥, while the Fenton reaction product flows along the path ③→④→⑤→②. The first cell is a coagulation and sedimentation zone, where recalcitrant organic wastewater with a flow rate of Q undergoes a coagulation reaction, removing most of the colloidal and suspended matter. The second cell is a homogeneous Fenton reaction zone, where the pH is controlled at approximately 3-5, and hydrogen peroxide is added. Under the catalytic action of ferrous ions, a homogeneous Fenton reaction occurs, oxidizing and degrading the recalcitrant organic matter in the wastewater. The third cell is a transition zone, where the homogeneous Fenton reaction is complete, forming the Fenton reaction product. One unit of OH- is added to the third cell. - 1 unit of H in the solution produced by the reaction with Fenton + A neutralization reaction occurs, neutralizing the free hydrogen ions in the wastewater. The 14Q Fenton reaction product enters the fourth compartment; the fourth compartment is the Fenton induction zone, where 1 unit of FeS2 powder is added. The fifth compartment contains Fe... 2+ The regeneration zone, in the fourth and fifth cells, contains FeS2 and 14Fe. 3+ A reaction occurs, producing 15Fe 2+ With 16H + 15Fe 2+ With 16H + The refluxed solution enters the second compartment, where it undergoes a homogeneous Fenton reaction with the hydrogen peroxide added to the second compartment, oxidizing and degrading recalcitrant organic matter. The Q-Fenton reaction product in the third compartment enters the effluent zone of the sixth compartment, where 3 units of OH- are added. - Fe in the solution produced by the Fenton reaction 3+ With 3OH - The reaction produces coagulant Fe(OH)3, which is refluxed back to the first compartment, while the purified water is discharged from the sixth compartment.

[0030] Preferably, the raw water enters the device from the bottom of the first coagulation and sedimentation zone. The first zone uses Fe(OH)3 generated in the sixth zone as a coagulant to first treat the raw water for coagulation and sedimentation, thereby reducing the amount of Fe in the subsequent Fenton reaction process. 3+The amount of loss resulting from coagulation reaction;

[0031] Preferably, 15 units of hydrogen peroxide are added to the homogeneous Fenton reaction zone in the second compartment, at the bottom of the second compartment, in conjunction with the Fe recirculated from the bottom of the fifth compartment. 2+ A homogeneous Fenton reaction occurs to produce ·OH, which oxidizes the recalcitrant organic matter flowing into the middle of the first compartment;

[0032] Preferably, the Fenton reaction product enters the transition zone of the third compartment from the upper part of the second compartment, and 1 unit of OH is added to the upper part of the third compartment. - The remaining 1 unit of H after neutralizing the Fenton reaction + The Fenton reaction product with a flow rate of 14Q enters the fourth compartment, the induction Fenton zone, from the bottom, and the Fenton reaction product with a flow rate of Q enters the sixth compartment, the neutralization and effluent zone, from the middle.

[0033] Preferably, 1 unit of FeS2 powder is added to the fourth compartment to induce Fenton reaction, and it is uniformly dispersed in the fourth compartment, where it reacts with the FeS2 powder in the Fenton reaction product solution that is added from the third compartment. 3+ The reaction is fully mixed, and the fifth Fe is reacted. 2+ The regeneration zone will regenerate Fe 3+ Completely reduced to Fe 2+ And produce an equivalent of H + The pH is automatically adjusted to 3-5 to create conditions for a homogeneous Fenton reaction. A screen should be installed between the fifth and second compartments. The screen aperture should be smaller than the FeS2 powder particle size to effectively reduce the loss of FeS2 powder.

[0034] Preferably, 3 units of OH- are added to the sixth effluent zone. - , and 1 unit of Fe flowing from the third cell into the sixth cell 3+ A precipitation reaction occurs to generate Fe(OH)3 coagulant, which is then refluxed back to the first compartment, at which point the effluent is neutral.

[0035] The present invention has been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described above. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention. Many other changes and modifications made without departing from the concept and scope of the present invention should be considered within the scope of protection of the present invention.

[0036] In the description of this specification, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0037] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A multiphase Fenton oxidation apparatus, characterized in that, The device includes a reaction tank; the reaction tank is divided into six equal-sized zones in two rows and three columns by partitions; Among them, the first row of reaction tanks is sequentially equipped with Fe 2+ Regeneration zone, homogeneous Fenton reaction zone, and coagulation sedimentation zone; The second row of reaction tanks is sequentially equipped with an induction Fenton zone, a transition zone, and an effluent zone; The coagulation sedimentation zone, homogeneous Fenton reaction zone, transition zone, and effluent zone are sequentially connected; the transition zone, induced Fenton zone, and Fe... 2+ The regeneration zone and the homogeneous Fenton reaction zone are sequentially connected; among them... The coagulation and sedimentation zone is used for coagulation reactions in recalcitrant organic wastewater to remove most of the colloidal and suspended matter in the wastewater. In the homogeneous Fenton reaction zone, hydrogen peroxide is added to induce a homogeneous Fenton reaction, thereby oxidizing and degrading the recalcitrant organic matter in the wastewater discharged from the coagulation and sedimentation zone. In the transition zone, OH is added. - It neutralizes the free hydrogen ions in the Fenton reaction product solution after the reaction in the homogeneous Fenton reaction zone; Inducing the Fenton zone, FeS2 powder is added to the Fenton reaction product solution to carry out a heterogeneous reaction; Fe 2+ Regeneration zone, FeS2 and 14Fe 3+ A reaction occurs, producing 15Fe 2+ With 16H + 15Fe 2+ With 16H + The refluxed water enters the homogeneous Fenton reaction zone and undergoes a homogeneous Fenton reaction with the hydrogen peroxide added to the homogeneous Fenton reaction zone, oxidizing and degrading recalcitrant organic matter. The Fenton reaction product with a flow rate of Q in the transition zone enters the effluent zone, and 3 units of OH- are added. - Fe in the solution produced by the Fenton reaction 3+ With 3OH - The reaction produces coagulant Fe(OH)3, which is then refluxed back to the coagulation and sedimentation zone, while the purified water is discharged from the effluent zone. 15 units of hydrogen peroxide were added to the lower part of the homogeneous Fenton reaction zone, and Fe was reacted with it. 2+ Fe recirculated in the lower part of the regeneration zone 2+ A homogeneous Fenton reaction occurs to produce ·OH, which oxidizes the recalcitrant organic matter flowing into the middle of the coagulation and sedimentation zone. The Fenton reaction product enters the transition zone from the upper part of the homogeneous Fenton reaction zone, and 1 unit of OH is added to the upper part of the transition zone. - The remaining 1 unit of H after neutralizing the Fenton reaction + A Fenton reaction product with a flow rate of 14Q enters the induction Fenton zone from the bottom, and a Fenton reaction product with a flow rate of Q enters the outlet zone from the middle. One unit of FeS2 powder was added to induce uniform dispersion in the Fenton zone, and then reacted with Fe in the Fenton reaction product solution flowing into the transition zone. 3+ The reaction is thoroughly mixed in Fe 2+ The regeneration zone will regenerate Fe 3+ Completely reduced to Fe 2+ And generate H + The pH is automatically adjusted to 3-5 to create conditions for a homogeneous Fenton reaction, Fe 2+ An interception mesh is set between the regeneration zone and the homogeneous Fenton reaction zone. The mesh aperture is smaller than the FeS2 powder particle size, which effectively reduces the loss of FeS2 powder. Add 3 units of OH to the effluent zone. - , and 1 unit of Fe flowing from the transition zone into the outlet zone 3+ A precipitation reaction occurs to generate Fe(OH)3 coagulant, which is then returned to the coagulation and sedimentation zone, at which point the effluent is neutral.

2. The multiphase Fenton oxidation apparatus according to claim 1, characterized in that, Raw water enters the device from the bottom of the coagulation and sedimentation zone. The coagulation and sedimentation zone uses Fe(OH)3 generated in the effluent zone as a coagulant to first treat the raw water to be treated by coagulation and sedimentation.

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