Wastewater treatment system and method for advanced oxidation coupling sulfur cycle biological denitrification

Abstract

The invention relates to a wastewater treatment system and method for advanced oxidation coupling sulfur cycle biological denitrification, the advanced oxidation system comprises: a first feed pump, a first UASB reactor and a first feeding device, the first feed pump is used for conveying wastewater to be treated to the first UASB reactor, and the first UASB reactor is used for conveying the wastewater to be treated to the second UASB reactor; the first feeding device is used for adding an advanced oxidation reactant into the first UASB reactor so as to carry out advanced oxidation reaction in the first UASB reactor; the sulfur circulation biological denitrification system comprises a second feeding pump, a second UASB reactor, a dissolving water tank and a second feeding device, the second feeding device is used for adding reaction materials into the dissolving water tank, and the second feeding pump is used for conveying treated wastewater from the dissolving water tank to the second UASB reactor; the treated wastewater and the reaction bacteria in the second UASB reactor are subjected to a sulfur cycle biological denitrification reaction; the sewage containing pollutants such as complex-state metals and nitrogen oxides can be efficiently and economically treated.

Description

Technical Field

[0001] The present invention relates to the technical field of water treatment, and particularly to a wastewater treatment system and method for advanced oxidation coupled with sulfur cycle biological denitrification. Background Art

[0002] With the rapid development of industry and the acceleration of urbanization, the problem of water pollution is becoming increasingly serious. Many industrial wastewaters and domestic sewage contain a large amount of pollutants such as complexed metals, organic substances, and nitrogen oxides. Traditional water treatment methods often have some limitations when dealing with such complex sewage.

[0003] When treating sewage by advanced oxidation technology, although it can effectively remove complexed metals in wastewater and degrade organic substances, the removal effect on nitrogen oxides in sewage is limited, and the treatment cost is relatively high.

[0004] The sulfur autotrophic denitrification technology has limitations in the mass transfer efficiency of solid sulfur sources, and problems such as easy loss of sulfide ions, subsequent sulfate pollution, and biological toxicity of sulfides will occur. The sulfur cycle biological system denitrification technology has certain advantages in treating nitrogen-containing wastewater. Summary of the Invention

[0005] In view of the above deficiencies of the current water treatment system, the present invention provides a wastewater treatment system and method for advanced oxidation coupled with sulfur cycle biological denitrification, which can give full play to the advantages of both, realize the efficient and economical treatment of sewage containing pollutants such as complexed metals and nitrogen oxides, and improve the water quality purification effect.

[0006] To achieve the above object, the embodiments of the present invention adopt the following technical solutions: According to the first aspect of the present invention, there is provided a wastewater treatment system for advanced oxidation coupled with sulfur cycle biological denitrification. The water treatment system includes: an advanced oxidation system, a sulfur cycle biological denitrification system, and a transfer pump; The advanced oxidation system realizes advanced oxidation reaction based on a first UASB reactor. The advanced oxidation system includes: a first feed pump, a first UASB reactor, and a first feeding device. The first feed pump is used to transport the wastewater to be treated to the first UASB reactor, and the first feeding device is used to add an advanced oxidation reagent to the first UASB reactor to carry out the advanced oxidation reaction in the first UASB reactor; The sulfur cycle biological denitrification system realizes the sulfur cycle biological denitrification reaction based on the second UASB reactor. The sulfur cycle biological denitrification system includes: a second feed pump, a second UASB reactor, a dissolution water tank, and a second feeding device. The second feeding device is used to add reaction materials into the dissolution water tank. The second feed pump is used to transport the wastewater under treatment from the dissolution water tank to the second UASB reactor, so that the wastewater under treatment undergoes the sulfur cycle biological denitrification reaction with the reaction bacteria in the second UASB reactor; The transfer pump is used to transport the wastewater under treatment after the advanced oxidation reaction to the dissolution water tank.

[0007] Optionally, the advanced oxidation system further includes: a first circulation pump, which is used to transport the wastewater under treatment flowing out of the first UASB reactor back to the first UASB reactor to undergo the advanced oxidation reaction.

[0008] Optionally, the sulfur cycle biological denitrification system further includes: a sludge circulation pump, a water bath tank, and a second circulation pump; the sludge circulation pump is used to transport the sludge flowing out of the second UASB reactor back to the second UASB reactor; the water bath tank is used to keep the second UASB reactor warm; the second circulation pump is used to circulate the hot water heated by the water bath tank in the second UASB reactor.

[0009] Optionally, both the first UASB reactor and the second UASB reactor are provided with an air outlet and a sampling port.

[0010] Optionally, the air outlet of the first UASB reactor and the air outlet of the second UASB reactor are both connected to a wet gas flowmeter through a rubber hose.

[0011] Optionally, the advanced oxidation reagent is CaFeCo and sodium hypochlorite. The CaFeCo is in a layered block structure, and the molar ratio of calcium, iron, and cobalt is 4:1:2.

[0012] Optionally, the reaction bacteria are anaerobic bacteria mixed with sulfate-reducing bacteria and Thiobacillus denitrificans, and the reaction materials are sodium sulfate, potassium nitrate, and glucose.

[0013] Optionally, both the first UASB reactor and the second UASB reactor are provided with a double-layer heat preservation structure made of acrylic materials.

[0014] Optionally, a stirrer is provided in the dissolution water tank to fully dissolve the reaction materials.

[0015] According to the second aspect of the present invention, a wastewater treatment method of advanced oxidation coupled with sulfur cycle biological denitrification is provided, and the above water treatment system is used for water treatment. The method steps are as follows: S1. Add an advanced oxidation reagent into the first UASB reactor; S2. The first feed pump transports the wastewater to be treated to the first UASB reactor, and an advanced oxidation reaction is carried out in the first UASB reactor; S3. The transfer pump transports the treated intermediate wastewater after the advanced oxidation reaction to the dissolution water tank; S4. Add reaction materials into the dissolution water tank; S5. The second feed pump transports the treated intermediate wastewater to the second UASB reactor, and a sulfur cycle biological denitrification reaction is carried out in the second UASB reactor.

[0016] The advantages of the present invention are as follows: 1. In the advanced oxidation system, the CaFeCo composite material is used as a catalyst to cooperate with sodium hypochlorite for advanced oxidation. Sodium hypochlorite in the water body decomposes into active substances such as hydroxyl radicals, chlorine radicals, singlet oxygen, and superoxide radicals. The highly active hydroxyl radicals react with organic substances to degrade the organic substances. Especially for amino and carboxyl organic compounds rich in electron groups, rapid degradation reactions can be carried out, and complex metal and organic substances in the wastewater can be effectively treated; 2. In the sulfur cycle biological denitrification system, sulfate-reducing bacteria use the electrons provided by the organic carbon source to reduce sulfate to sulfide under anaerobic conditions, such as H2S, HS - , S 2- etc. These generated sulfides serve as electron acceptors, and electrons are provided by nitrate nitrogen in the water sample. Nitrate nitrogen is converted into nitrogen gas under the action of sulfur autotrophic denitrifying bacteria, and sulfide is finally converted into sulfate radical, which can effectively treat nitrogen oxides in the wastewater; 3. The wastewater treatment process flow is simple, easy to manage and control; the start-up period is short; 4. The operation difficulty is low, and the operation parameters can be flexibly adjusted according to factors such as the influent flow rate and water quality of the wastewater, so that the system can adapt to the wastewater treatment requirements of different types and different water qualities, improving the versatility and adaptability of the system; 5. The problems of high organic matter concentration and excessive nitrate content in the wastewater can be quickly solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0018] Figure 1 It is a three-dimensional view of the advanced oxidation system described in the present invention; Figure 2 Is the three-dimensional view of the sulfur cycle biological denitrification system described in the present invention; Figure 3 Is the front view of the advanced oxidation system described in the present invention; Figure 4 Is the front view of the sulfur cycle biological denitrification system described in the present invention; Figure 5 Is the sectional view of the advanced oxidation system described in the present invention; Figure 6 Is the sectional view of the sulfur cycle biological denitrification system described in the present invention; Figure 7 Is the top view of the advanced oxidation system described in the present invention; Figure 8 Is the top view of the sulfur cycle biological denitrification system described in the present invention; Figure 9 Is the flow chart of the wastewater treatment method described in the present invention.

[0019] In the figure: 100, advanced oxidation system; 101, first feed pump; 102, first UASB reactor; 1021, first gas outlet; 1022, first water inlet; 1023, second water inlet; 1024, first water outlet; 1025, second water outlet; 103, first circulation pump; 104, first electric control box, 200, sulfur cycle biological denitrification system; 201, second feed pump; 202, second UASB reactor; 2021, second gas outlet; 2022, third water inlet; 2023, fourth water inlet; 2024, fifth water inlet; 2025, third water outlet; 2026, fourth water outlet; 2027, fifth water outlet; 203, dissolution water tank; 204, sludge circulation pump; 205, water bath tank; 206, second circulation pump, 207, second electric control box, 208, water outlet tank; 209, agitator; 300, delivery pump. Detailed implementation manners

[0020] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0021] Embodiment 1

[0022] As Figures 1-8As shown in the figure, a wastewater treatment system for advanced oxidation coupled with sulfur cycle biological denitrification, the water treatment system comprising: an advanced oxidation system 100, a sulfur cycle biological denitrification system 200, and a transfer pump 300; the advanced oxidation system 100 realizes advanced oxidation reaction based on a first UASB reactor 102, the advanced oxidation system 100 comprising: a first feed pump 101, a first UASB reactor 102, and a first feeding device, the first feed pump 101 being used for conveying wastewater to be treated to the first UASB reactor 102, the first feeding device being used for adding an advanced oxidation reagent into the first UASB reactor 102 to carry out the advanced oxidation reaction in the first UASB reactor 102; the sulfur cycle biological denitrification system 200 realizes the sulfur cycle biological denitrification reaction based on a second UASB reactor 202, the sulfur cycle biological denitrification system 200 comprising: a second feed pump 201, a second UASB reactor 202, a dissolution water tank 203, and a second feeding device, the second feeding device being used for adding reaction materials into the dissolution water tank 203, the second feed pump 201 being used for conveying the wastewater in treatment from the dissolution water tank 203 to the second UASB reactor 202, so that the wastewater in treatment reacts with reaction bacteria in the second UASB reactor 202 to carry out the sulfur cycle biological denitrification reaction; the transfer pump 300 is used for conveying the wastewater in treatment after the advanced oxidation reaction to the dissolution water tank 203.

[0023] Specifically, the advanced oxidation system 100 includes a feed water tank, a first feed pump 101, a first UASB reactor 102, a first feeding device, and a first electric control box 104. The first UASB reactor 102 is provided with a first water inlet 1022, a second water inlet 1023, a first water outlet 1024, and a second water outlet 1025. The sulfur cycle biological denitrification system 200 includes a second feed pump 201, a second UASB reactor 202, a dissolution water tank 203, a second feeding device, a water outlet tank 208, and a second electric control box 207. The second UASB reactor 202 is provided with a third water inlet 2022, a fourth water inlet 2023, a fifth water inlet 2024, a third water outlet 2025, a fourth water outlet 2026, and a fifth water outlet 2027. When the first UASB reactor 102 is operating, an advanced oxidation reagent is added thereto. The wastewater to be treated enters the first UASB reactor 102 through the first water inlet 1022 from the feed water tank by the first feed pump 101. An advanced oxidation reaction is carried out in the first UASB reactor 102. The treated wastewater comes out from the water outlet of the first UASB reactor 102 and enters the dissolution water tank 203 through a transfer pump 300. Reaction materials are added to the dissolution water tank 203. The treated wastewater enters the second UASB reactor 202 through the third water inlet 2022 by the second feed pump 201. A sulfur cycle biological denitrification reaction is carried out in the second UASB reactor 202. The treated wastewater enters the water outlet tank 208 from the water outlet of the second UASB reactor 202. The first electric control box 104 and the second electric control box 207 are used to control and protect their electrical equipment.

[0024] Example 2

[0025] Such as Figures 1-8As shown in the figure, a wastewater treatment system for advanced oxidation coupled with sulfur cycle biological denitrification, the water treatment system includes: an advanced oxidation system 100, a sulfur cycle biological denitrification system 200, and a transfer pump 300; the advanced oxidation system 100 realizes advanced oxidation reaction based on the first UASB reactor 102, and the advanced oxidation system 100 includes: a first feed pump 101, a first UASB reactor 102, and a first feeding device, the first feed pump 101 is used to transport the wastewater to be treated to the first UASB reactor 102, and the first feeding device is used to add an advanced oxidation reagent into the first UASB reactor 102 to carry out the advanced oxidation reaction in the first UASB reactor 102; the sulfur cycle biological denitrification system 200 realizes the sulfur cycle biological denitrification reaction based on the second UASB reactor 202, and the sulfur cycle biological denitrification system 200 includes: a second feed pump 201, a second UASB reactor 202, a dissolution water tank 203, and a second feeding device, the second feeding device is used to add reaction materials into the dissolution water tank 203, and the second feed pump 201 is used to transport the wastewater in treatment from the dissolution water tank 203 to the second UASB reactor 202, so that the wastewater in treatment reacts with the reaction bacteria in the second UASB reactor 202 to carry out the sulfur cycle biological denitrification reaction; the transfer pump 300 is used to transport the wastewater in treatment after the advanced oxidation reaction to the dissolution water tank 203.

[0026] Further, as an option, the advanced oxidation system 100 further includes: a first circulation pump 103, which is used to transport the wastewater in treatment flowing out of the first UASB reactor 102 back to the first UASB reactor 102 to carry out the advanced oxidation reaction; to increase the contact time and reaction degree between the wastewater and the advanced oxidation reagent, enhance the removal effect on complexed metals and organic substances, and improve the treatment efficiency.

[0027] Further, the sulfur cycle biological denitrification system 200 further includes: a sludge circulation pump 204, a water bath tank 205, and a second circulation pump 206; the sludge circulation pump 204 is used to transport the sludge flowing out of the second UASB reactor 202 back to the second UASB reactor 202; the water bath tank 205 is used to keep the second UASB reactor 202 warm; the second circulation pump 206 is used to circulate the hot water heated by the water bath tank 205 in the second UASB reactor 202; the design of the sludge circulation pump 204 enables the sludge to be recycled, can retain the reaction bacteria, and ensures the continuous and efficient progress of the reaction; the design of the water bath tank 205 can provide a stable temperature to provide a suitable environment for the reaction bacteria and improve the efficiency of the sulfur cycle biological denitrification reaction.

[0028] Specifically, the advanced oxidation system 100 includes a water inlet tank, a first feed pump 101, a first circulation pump 103, a first UASB reactor 102, a first feeding device, and a first electric control box 104. The first UASB reactor 102 is provided with a first water inlet 1022, a second water inlet 1023, a first water outlet 1024, and a second water outlet 1025. The sulfur cycle biological denitrification system 200 includes a second feed pump 201, a sludge circulation pump 204, a water bath tank 205, a second circulation pump 206, a second UASB reactor 202, a dissolution water tank 203, a second feeding device, a water outlet tank 208, and a second electric control box 207. The second UASB reactor 202 is provided with a third water inlet 2022, a fourth water inlet 2023, a fifth water inlet 2024, a third water outlet 2025, a fourth water outlet 2026, and a fifth water outlet 2027. When the first UASB reactor 102 is operating, an advanced oxidation reagent is added thereto. The wastewater to be treated enters the first UASB reactor 102 through the first water inlet 1022 from the water inlet tank by the first feed pump 101. An advanced oxidation reaction occurs in the first UASB reactor 102. The treated wastewater comes out from the first water outlet 1024 of the first UASB reactor 102 and then enters the first UASB reactor 102 again through the second water inlet 1023 of the first UASB reactor 102 by the first circulation pump 103. After that, the treated wastewater flows out from the second water outlet 1025 of the first UASB reactor 102 and enters the dissolution water tank 203 through the transfer pump 300. Reaction materials are added to the dissolution water tank 203. The treated wastewater enters the second UASB reactor 202 through the third water inlet 2022 by the second feed pump 201. A sulfur cycle biological denitrification reaction occurs in the second UASB reactor 202. The treated wastewater enters the water outlet tank 208 from the third water outlet 2025 of the second UASB reactor 202. After the sludge in the wastewater comes out from the fourth water outlet 2026, it re-enters the second UASB reactor 202 through the fourth water inlet 2023 by the sludge circulation pump 204. The water bath tank 205 is provided to keep the second UASB reactor 202 warm. The hot water coming out from the fifth water outlet 2027 re-enters the second UASB reactor 202 through the fifth water inlet 2024 by the second circulation pump 206. The first electric control box 104 and the second electric control box 207 are used to control and protect their electrical equipment.

[0029] Example 3

[0030] Such as Figures 1-8As shown in the figure, a wastewater treatment system for advanced oxidation coupled with sulfur cycle biological denitrification, the water treatment system comprising: an advanced oxidation system 100, a sulfur cycle biological denitrification system 200, and a transfer pump 300; the advanced oxidation system 100 realizing advanced oxidation reaction based on a first UASB reactor 102, the advanced oxidation system 100 comprising: a first feed pump 101, a first UASB reactor 102, and a first dosing device, the first feed pump 101 being used for conveying wastewater to be treated to the first UASB reactor 102, the first dosing device being used for adding an advanced oxidation reagent into the first UASB reactor 102 to carry out the advanced oxidation reaction in the first UASB reactor 102; the sulfur cycle biological denitrification system 200 realizing the sulfur cycle biological denitrification reaction based on a second UASB reactor 202, the sulfur cycle biological denitrification system 200 comprising: a second feed pump 201, a second UASB reactor 202, a dissolution water tank 203, and a second dosing device, the second dosing device being used for adding reaction materials into the dissolution water tank 203, the second feed pump 201 being used for conveying the wastewater in treatment from the dissolution water tank 203 to the second UASB reactor 202, so that the wastewater in treatment reacts with the reaction bacteria in the second UASB reactor 202 to carry out the sulfur cycle biological denitrification reaction; the transfer pump 300 being used for conveying the wastewater in treatment after the advanced oxidation reaction to the dissolution water tank 203.

[0031] Further, an air outlet and a sampling port are provided on both the first UASB reactor 102 and the second UASB reactor 202. A first air outlet 1021 is provided on the first UASB reactor, and a second air outlet 2021 is provided on the second UASB reactor; facilitating real-time monitoring of the gas generation situation and water quality change during the reaction process, timely understanding of the treatment effect, and providing a basis for process adjustment.

[0032] Further, the air outlets of the first UASB reactor 102 and the second UASB reactor 202 are both connected to a wet gas flowmeter through rubber hoses; accurately obtaining gas flow data, more accurately analyzing the reaction process and efficiency, and assisting in optimizing the reaction conditions.

[0033] Further, the advanced oxidation reagent is CaFeCo and sodium hypochlorite, the CaFeCo is in a block structure, and the molar ratio of calcium, iron, and cobalt is 4:1:2; the CaFeCo composite catalyst improves the oxidation ability of sodium hypochlorite, can effectively treat the complexed metals and organic matters in wastewater, especially the organic compounds rich in electron groups.

[0034] Furthermore, the reaction bacteria are anaerobic bacteria mixed with sulfate-reducing bacteria and Thiobacillus denitrificans, and the reaction materials are sodium sulfate, potassium nitrate, and glucose. The sulfate-reducing bacteria use the electrons provided by the organic carbon source (such as glucose) to reduce sodium sulfate to sulfide under anaerobic conditions. The sulfide, as an electron acceptor, under the action of Thiobacillus denitrificans, obtains electrons from the nitrate nitrogen in the water sample, and the nitrate nitrogen is converted into nitrogen gas under the action of sulfur autotrophic denitrifying bacteria, while the sulfide is ultimately converted into sulfate.

[0035] Furthermore, both the first UASB reactor 102 and the second UASB reactor 202 are provided with a double-layer thermal insulation structure made of acrylic materials, providing a stable temperature environment for the advanced oxidation reaction and the sulfur cycle biological denitrification reaction, facilitating the reaction, and improving the treatment effect and system stability.

[0036] Furthermore, a stirrer 209 is provided in the dissolution water tank 203 to ensure sufficient dissolution of the reaction materials, ensuring uniform dispersion of the reaction materials, improving the reaction efficiency, and ensuring the smooth progress of the sulfur cycle biological denitrification reaction.

[0037] The above also has the following designs: 1. The water inlet tank, the dissolution water tank 203, and the water outlet tank 208 are made of high-quality PVC materials; 2. The water bath tank 205 is a 304 stainless steel frame.

[0038] Example 4

[0039] The electroplating wastewater with a nickel concentration of 15 mg / L after dilution is first adjusted to pH 8 with H2SO4 and NaOH solutions. 0.5 g / L of CaFeCo composite material and 3 ml / L of NaClO solution are added to the first UASB reactor 102. The hydraulic retention time is 90 min, the rotation speed of the first feed pump 101 is 100 rpm, and the temperature is room temperature. Starting from the inlet water to the outlet water of the first UASB reactor 102 is taken as a cycle, and the cycle time is 5 h. The treated electroplating wastewater is used as the inlet water for the sulfur cycle microbial denitrification process. The first UASB reactor 102 is connected to the dissolution water tank 203. 0.1 g / L of sodium sulfate, 0.06 g / L of potassium nitrate, and glucose are added to the dissolution water tank 203, with C / N = 1.5. The wastewater after adding the chemicals enters the second UASB reactor 202 through the second feed pump 201. The hydraulic retention time is 720 min, and the temperature is room temperature. After the advanced oxidation and sulfur cycle biological denitrification treatment, the nickel removal rate is 96.9% and the nitrate nitrogen removal rate is 98.24%.

[0040] Example 5

[0041] The electroplating wastewater with a nickel concentration of 15 mg / L after dilution is first adjusted to a pH of 8 with H2SO4 and NaOH solutions. 0.4 g / L of CaFeCo composite material and 3 ml / L of NaClO solution are added to the first UASB reactor 102. The hydraulic retention time is 90 min, the rotation speed of the first feed pump 101 is 100 rpm, and the temperature is room temperature. Starting from the inlet water to the outlet water of the first UASB reactor 102 is taken as a cycle, and the cycle time is 5 h. The treated electroplating wastewater is used as the inlet water for the sulfur cycle microbial denitrification process. The first UASB reactor 102 is connected to the dissolution water tank 203. 0.1 g / L of sodium sulfate, 0.06 g / L of potassium nitrate, and glucose are added to the dissolution water tank 203, with C / N = 1.5. The wastewater after adding the chemicals enters the second UASB reactor 202 through the second feed pump 201. The hydraulic retention time is 480 min, and the temperature is room temperature. After the wastewater is treated by advanced oxidation and sulfur cycle biological denitrification, the nickel removal rate is 94.2% and the nitrate nitrogen removal rate is 93.75%.

[0042] Example 6

[0043] As Figure 9 shown, a wastewater treatment method coupling advanced oxidation and sulfur cycle biological denitrification uses the above water treatment system for water treatment. The method steps are as follows: S1. Add an advanced oxidation reagent to the first UASB reactor 102; S2. The first feed pump 101 transports the wastewater to be treated to the first UASB reactor 102, and an advanced oxidation reaction occurs in the first UASB reactor 102; S3. The transfer pump 300 transports the treated intermediate wastewater after the advanced oxidation reaction to the dissolution water tank 203; S4. Add reaction materials to the dissolution water tank 203; S5. The second feed pump 201 transports the intermediate wastewater to the second UASB reactor 202, and a sulfur cycle biological denitrification reaction occurs in the second UASB reactor 202.

[0044] As described above, only the specific embodiments of the present invention are provided, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims described above.

Claims

1. An advanced oxidation coupled sulfur cycle biological denitrification wastewater treatment system, the wastewater treatment system comprising: Advanced oxidation system, sulfur cycle biological denitrification system and delivery pump; characterized in that, The advanced oxidation system realizes advanced oxidation reaction based on the first UASB reactor. The advanced oxidation system includes: a first feed pump, a first UASB reactor and a first feeding device. The first feed pump is used to transport the wastewater to be treated to the first UASB reactor, and the first feeding device is used to add an advanced oxidation reagent to the first UASB reactor to carry out the advanced oxidation reaction in the first UASB reactor; The sulfur cycle biological denitrification system realizes the sulfur cycle biological denitrification reaction based on the second UASB reactor. The sulfur cycle biological denitrification system includes: a second feed pump, a second UASB reactor, a dissolution water tank and a second feeding device. The second feeding device is used to add reaction materials into the dissolution water tank, and the second feed pump is used to transport the wastewater being treated from the dissolution water tank to the second UASB reactor, so that the wastewater being treated reacts with the reaction bacteria in the second UASB reactor to carry out the sulfur cycle biological denitrification reaction; The delivery pump is used to transport the wastewater being treated after the advanced oxidation reaction to the dissolution water tank.

2. The wastewater treatment system according to claim 1, characterized in that, The advanced oxidation system further includes: a first circulation pump, which is used to transport the wastewater being treated flowing out of the first UASB reactor back to the first UASB reactor to carry out the advanced oxidation reaction.

3. The wastewater treatment system according to claim 1, characterized in that, The sulfur cycle biological denitrification system further includes: a sludge circulation pump, a water bath tank and a second circulation pump; the sludge circulation pump is used to transport the sludge flowing out of the second UASB reactor back to the second UASB reactor; the water bath tank is used to keep the second UASB reactor warm; the second circulation pump is used to circulate the hot water heated by the water bath tank in the second UASB reactor.

4. The wastewater treatment system according to claim 1, wherein Both the first UASB reactor and the second UASB reactor are provided with an air outlet and a sampling port.

5. The wastewater treatment system according to claim 4, wherein, The air outlets of the first UASB reactor and the second UASB reactor are both connected to a wet gas flowmeter through rubber hoses.

6. The wastewater treatment system according to claim 1, characterized in that, The advanced oxidation reagent is CaFeCo and sodium hypochlorite. CaFeCo is in a layered block structure, and the molar ratio of calcium, iron and cobalt is 4:1:

2.

7. The wastewater treatment system according to claim 1, characterized in that, The reaction bacteria are anaerobic bacteria mixed by sulfate-reducing bacteria and Thiobacillus denitrificans, and the reaction materials are sodium sulfate, potassium nitrate and glucose.

8. The wastewater treatment system according to claim 1, characterized in that, Both the first UASB reactor and the second UASB reactor are provided with a double-layer heat preservation structure made of acrylic materials.

9. The wastewater treatment system according to claim 1, characterized in that, A stirrer is arranged in the dissolution water tank to fully dissolve the reaction materials.

10. An advanced oxidation coupled with sulfur cycle biological denitrification wastewater treatment method, characterized in that, Using the wastewater treatment system according to any one of claims 1-9 for water treatment, the method steps are as follows: S1. Add an advanced oxidation reagent to the first UASB reactor; S2. The first feed pump transports the wastewater to be treated to the first UASB reactor, and an advanced oxidation reaction is carried out in the first UASB reactor; S3. The delivery pump transports the wastewater being treated after the advanced oxidation reaction to the dissolution water tank; S4. Add reaction materials to the dissolution water tank; S5. The second feed pump conveys the wastewater being treated to the second UASB reactor, where sulfur cycle biological denitrification reaction takes place.

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