Wastewater treatment system

Abstract

The utility model relates to a wastewater treatment system. The wastewater treatment system comprises a mixing device, a first reaction kettle, a second reaction kettle, a neutralization tank and a settling tank, a wastewater outlet of the mixing device is in fluid communication with a first water inlet of the first reaction kettle and is optionally in fluid communication with a second water inlet of the second reaction kettle; a first water outlet of the first reaction kettle is in fluid communication with a third water inlet of the neutralization tank or a second water inlet of the second reaction kettle in a convertible manner; a second water outlet of the second reaction kettle is in fluid communication with a third water inlet of the neutralization tank; a third water outlet of the neutralization tank is in fluid communication with a fourth water inlet of the settling tank. The wastewater treatment system disclosed by the utility model is high in adaptability to fluctuation of sewage quantity and water quality.

Description

Technical Field

[0001] The present disclosure relates to the field of water treatment, and in particular, to a wastewater treatment system. Background Art

[0002] Treatment of organic wastewater with a low B / C ratio has long been a challenge in water treatment technology. Due to its low B / C ratio and poor biodegradability, this type of wastewater is difficult to treat directly using biochemical methods. Conventional methods such as filtration and flocculation are ineffective, while advanced treatment technologies such as activated carbon adsorption are prohibitively expensive. Membrane separation technology also presents challenges due to high investment costs and practical issues such as membrane fouling.

[0003] Advanced oxidation (AO) is widely used to remove non-biodegradable organic matter from water, potentially increasing the B / C ratio of wastewater and enabling further biochemical treatment. Current AO technologies primarily include chemical oxidation, electrochemical oxidation, wet oxidation, supercritical water oxidation, and photocatalytic oxidation. Commonly used oxidants in these methods include Fenton's reagent, ozone, and sodium hypochlorite.

[0004] Among them, the catalytic oxidation method using hydrogen peroxide as oxidant to treat low B / C ratio organic wastewater has the characteristics of good treatment effect, simple operation, rapid reaction, low investment cost, and no ozone tail gas pollution, which has been widely recognized.

[0005] However, existing catalytic oxidation devices have poor operational flexibility and are not adaptable to fluctuations in sewage water quality and water volume. Therefore, it is necessary to develop a catalytic oxidation device that is highly adaptable to fluctuations in sewage water volume and water quality. Utility Model Content

[0006] The object of the present disclosure is to provide a wastewater treatment system that is highly adaptable to fluctuations in wastewater volume and quality.

[0007] In order to achieve the above object, the present disclosure provides a wastewater treatment system, which includes a mixing device, a first reactor, a second reactor, a neutralization tank and a sedimentation tank;

[0008] The mixing device includes an acid and catalyst inlet, a wastewater inlet and a wastewater outlet; the first reactor includes a first oxidant inlet, a first water inlet and a first water outlet; the second reactor includes a second oxidant inlet, a second water inlet and a second water outlet; the neutralization tank includes an alkali inlet, a third water inlet and a third water outlet, and the settling tank includes a fourth water inlet, a fourth water outlet and a sludge outlet;

[0009] The wastewater outlet of the mixing device is in fluid communication with the first water inlet of the first reactor, and optionally in fluid communication with the second water inlet of the second reactor;

[0010] The first water outlet of the first reactor is switchably connected to the third water inlet of the neutralization tank or the second water inlet of the second reactor; the second water outlet of the second reactor is connected to the third water inlet of the neutralization tank;

[0011] The third water outlet of the neutralization tank is in fluid communication with the fourth water inlet of the settling tank.

[0012] Optionally, the system further comprises a first pipeline, a second pipeline and a third pipeline;

[0013] The first pipeline is used to connect the sewage outlet of the mixing device and the first sewage inlet of the first reactor, and optionally connect the sewage outlet of the mixing device and the second sewage inlet of the second reactor;

[0014] The second pipeline is used to connect the second water outlet of the second reactor and the third water inlet of the neutralization tank, and is switchably used to connect the first water outlet of the first reactor to the third water inlet of the neutralization tank or to the second water inlet of the second reactor;

[0015] The third pipeline is used to connect the third water outlet of the neutralization tank and the fourth water inlet of the sedimentation tank.

[0016] Optionally, the first pipeline includes a first main pipeline, a first branch pipeline and a second branch pipeline;

[0017] A first three-way valve is provided on the first main line, wherein the inlet of the first three-way valve is in fluid communication with the outlet of the first main line, a first bypass port of the first three-way valve is in fluid communication with the inlet of the first branch line, the outlet of the first branch line is in fluid communication with the first water inlet of the first reactor, a second bypass port of the first three-way valve is in fluid communication with the inlet of the second branch line, and the outlet of the second branch line is in fluid communication with the second water inlet of the second reactor;

[0018] The second pipeline includes a second main pipeline, a third branch pipeline and a fourth branch pipeline;

[0019] A second three-way valve and a third three-way valve are provided on the second main pipe, the first bypass interface and the inlet of the second three-way valve are located on the second main pipe, the second bypass interface of the second three-way valve is fluidically connected to the inlet end of the third branch pipe, and the outlet end of the third branch pipe is fluidically connected to the third water inlet of the neutralization tank, the first bypass interface and the inlet of the third three-way valve are located on the second main pipe, the second bypass interface of the third three-way valve is fluidically connected to the inlet end of the fourth branch pipe, and the outlet end of the fourth branch pipe is fluidically connected to the second water outlet of the second reactor.

[0020] Optionally, the first water inlet of the first reactor is located on the bottom side wall of the first reactor, and the first water outlet is located on the top side wall of the first reactor;

[0021] The ratio of the distance between the first water inlet and the bottom surface of the first reactor to the height of the first reactor is 1:(3-100), and the ratio of the distance between the first water outlet and the bottom surface of the first reactor to the height of the first reactor is 1:(1.01-1.5).

[0022] Optionally, the second water inlet of the second reactor is located on the bottom side wall of the second reactor, and the second water outlet is located on the top side wall of the second reactor;

[0023] The ratio of the distance between the second water inlet and the bottom surface of the second reactor to the height of the second reactor is 1:(3-100), and the ratio of the distance between the second water outlet and the bottom surface of the second reactor to the height of the second reactor is 1:(1.01-1.5).

[0024] Optionally, the system further comprises an acid delivery line and a catalyst delivery line, wherein the outlet of the acid delivery line is in fluid communication with the acid and catalyst inlet of the mixing device, and the catalyst delivery line is in fluid communication with the acid and catalyst inlet of the mixing device.

[0025] Optionally, the system further includes a first oxidant delivery pipeline and a second oxidant delivery pipeline, wherein the outlet of the first oxidant delivery pipeline is fluidically connected to the first oxidant inlet of the first reactor, and the outlet of the second oxidant delivery pipeline is fluidically connected to the second oxidant inlet of the second reactor.

[0026] Optionally, a stirring mechanism is independently provided in the mixing device, the first reactor, the second reactor and the neutralization tank.

[0027] Optionally, the stirring mechanism is a stirring paddle, aeration stirring or hydraulic reflux stirring.

[0028] Optionally, the sedimentation tank is a vertical flow sedimentation tank, a radial flow sedimentation tank or a horizontal flow sedimentation tank.

[0029] Through the above technical solution, the system disclosed in the present invention is provided with a dual reactor, which can adaptively change the connection form of the reactor according to the properties of the wastewater to be treated, so that the wastewater treatment system has better adaptability to fluctuations in sewage water volume and water quality.

[0030] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following detailed description, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:

[0032] Figure 1 It is a flow chart of a specific embodiment of the wastewater treatment system disclosed in the present invention.

[0033] Description of Reference Numerals

[0034] DETAILED DESCRIPTION

[0035] The following describes the specific embodiments of the present disclosure in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present disclosure and are not intended to limit the present disclosure.

[0036] In the present disclosure, unless otherwise stated, directional words such as “up, down, left, right” generally refer to “up, down, left, right” when the system of the present disclosure can be used normally.

[0037] like Figure 1 As shown, the present disclosure provides a wastewater treatment system, which includes a mixing device 1, a first reactor 2, a second reactor 3, a neutralization tank 4 and a sedimentation tank 5; the mixing device 1 includes an acid and catalyst inlet, a wastewater inlet and a wastewater outlet; the first reactor 2 includes a first oxidant inlet, a first water inlet and a first water outlet; the second reactor 3 includes a second oxidant inlet, a second water inlet and a second water outlet; the neutralization tank 4 includes an alkali inlet, a third water inlet and a third water outlet, and the sedimentation tank 4 includes a fourth water inlet, a fourth water outlet and a sludge outlet; the wastewater outlet of the mixing device 1 is fluidically connected to the first water inlet of the first reactor 2, and optionally to the second water inlet of the second reactor 3; the first water outlet of the first reactor 2 is switchably fluidically connected to the third water inlet of the neutralization tank 4 or the second water inlet of the second reactor 3; the second water outlet of the second reactor 3 is fluidically connected to the third water inlet of the neutralization tank 4; the third water outlet of the neutralization tank 4 is fluidically connected to the fourth water inlet of the sedimentation tank 5.

[0038] The wastewater treatment system disclosed in the present invention is provided with a dual reactor, which can be adjusted to be used in a two-stage series form or a parallel form according to the different properties of the wastewater, so that the system disclosed in the present invention has a strong adaptability to fluctuations in wastewater water volume and water quality.

[0039] In one embodiment of the present disclosure, the system further includes a first pipeline 7, a second pipeline 8 and a third pipeline 9; the first pipeline 7 is used to connect the sewage outlet of the mixing device 1 and the first sewage inlet of the first reactor 2, and optionally connect the sewage outlet of the mixing device 1 and the second sewage inlet of the second reactor 3; the second pipeline 8 is used to connect the second water outlet of the second reactor 3 and the third water inlet of the neutralization tank 4, and can be used to switchably connect the first water outlet of the first reactor 2 with the third water inlet of the neutralization tank 4 or with the second water inlet of the second reactor 3; the third pipeline 9 is used to connect the third water outlet of the neutralization tank with the fourth water inlet of the settling tank 5.

[0040] In a specific embodiment of the present disclosure, the system further includes a first pipeline 7, a second pipeline 8, and a third pipeline 9; the first pipeline 7 is used to connect the sewage outlet of the mixing device 1 with the first sewage inlet of the first reactor 2, and also connect the sewage outlet of the mixing device 1 with the second sewage inlet of the second reactor 3; the second pipeline 8 is used to connect the second water outlet of the second reactor 3 with the third water inlet of the neutralization tank 4, and is used to connect the first water outlet of the first reactor 2 with the third water inlet of the neutralization tank 4; the third pipeline 9 is used to connect the third water outlet of the neutralization tank with the fourth water inlet of the settling tank. In this embodiment, the first and second reactors in the wastewater treatment system are arranged in parallel, which is suitable for treating wastewater with a relatively high BC ratio and good water quality, and has high treatment efficiency.

[0041] In another specific embodiment of the present disclosure, the system further includes a first pipeline 7, a second pipeline 8, and a third pipeline 9. The first pipeline 7 is used to connect the sewage outlet of the mixing device with the first sewage inlet of the first reactor 2. The second pipeline 8 is used to connect the second water outlet of the second reactor 2 with the third water inlet of the neutralization tank 4, and is used to connect the first water outlet of the first reactor 2 with the second water inlet of the second reactor 3. The third pipeline 8 is used to connect the third water outlet of the neutralization tank 4 with the fourth water inlet of the settling tank 5. In this embodiment, the first and second reactors in the wastewater treatment system are arranged in series, which is suitable for treating wastewater with a relatively high BC ratio and high water quality. It has a good treatment effect of improving the wastewater BC ratio and a high utilization rate of the water treatment agent.

[0042] In a specific embodiment of the present disclosure, the first pipeline includes a first main pipeline, a first branch pipeline 71 and a second branch pipeline 72; a first three-way valve 11 is provided on the first main pipeline, the inlet of the first three-way valve 11 is fluidically connected to the outlet end of the first main pipeline, the first bypass interface of the first three-way valve 11 is fluidically connected to the inlet end of the first branch pipeline 71, the outlet end of the first branch pipeline 71 is fluidically connected to the first water inlet of the first reactor 2, the second bypass interface of the first three-way valve 11 is fluidically connected to the inlet end of the second branch pipeline 72, and the outlet end of the second branch pipeline 72 is connected to the second water inlet of the second reactor 3; the second pipeline 8 includes a second The main line, the third branch line 81, and the fourth branch line 82 are provided with a second three-way valve 12 and a third three-way valve 13 on the second main line 8. The first bypass interface and inlet of the second three-way valve 12 are located on the second main line. The second bypass interface of the second three-way valve 12 is in fluid communication with the inlet end of the third branch line 81. The outlet end of the second branch line is in fluid communication with the third water inlet of the neutralization tank 4. The first bypass interface and inlet of the third three-way valve 13 are located on the second main line. The second bypass interface of the third three-way valve 13 is in fluid communication with the inlet end of the fourth branch line 82. The outlet end of the fourth branch line 82 is in fluid communication with the second water outlet of the second reactor 3. In this embodiment, by providing three-way valves on the first and second lines, the connection relationship of the reactors in the system can be adjusted more flexibly, so that the system of the present disclosure has a high adaptability to fluctuations in sewage water volume and water quality.

[0043] In a specific embodiment of the present disclosure, the first water inlet of the first reactor 2 is located on the bottom side wall of the first reactor, and the first water outlet is located on the top side wall of the first reactor 2; the ratio of the distance from the first water inlet to the bottom surface of the first reactor to the height of the first reactor is 1:(3-100), preferably 1:(5-20), and the ratio of the distance from the first water outlet to the surface of the first reactor to the height of the first reactor is 1:(1.01-1.5), preferably 1:(1.05-1.2).

[0044] In a specific embodiment of the present disclosure, the second water inlet of the second reactor 3 is located on the bottom side wall of the second reactor 3, and the second water outlet is located on the top side wall of the second reactor 3; the ratio of the distance from the second water inlet to the bottom surface of the second reactor to the height of the second reactor is 1:(3-100), preferably 1:(5-20), and the ratio of the distance from the second water outlet to the bottom surface of the second reactor to the height of the second reactor is 1:(1.01-1.5), preferably 1:(1.05-1.2).

[0045] In a specific embodiment of the present disclosure, the system further comprises an acid delivery pipeline 14 and a catalyst delivery pipeline 15, wherein the outlet of the acid delivery pipeline is fluidly connected to the acid and catalyst inlet of the mixing device 1, and the outlet of the catalyst delivery pipeline 14 is fluidly connected to the acid and catalyst inlet of the mixing device.

[0046] In a specific embodiment of the present disclosure, the system further includes a first oxidant delivery line 16 and a second oxidant delivery line 17. The outlet of the first oxidant delivery line 16 is in fluid communication with the first oxidant inlet of the first reactor 2, and the outlet of the second oxidant delivery line 17 is in fluid communication with the second oxidant inlet of the second reactor 3. In the present disclosure, the material of the oxidant delivery line can be an oxidation-resistant material, such as 316L stainless steel, titanium, Hastelloy, etc.

[0047] In a specific embodiment of the present disclosure, a stirring mechanism is independently provided in the mixing device 1, the first reactor 2, the second reactor 3, and the neutralization tank 4. The stirring mechanism is well known to those skilled in the art, and for example, the stirring mechanism may be a stirring paddle, aeration stirring, or hydraulic reflux stirring.

[0048] According to the present disclosure, the settling tank is commonly used by those skilled in the art. In a specific embodiment of the present disclosure, the settling tank is a vertical flow settling tank, a radial flow settling tank or a horizontal flow settling tank.

[0049] In a specific embodiment of the present disclosure, the system further comprises a sewage conveying pipeline 6 , the outlet of the sewage conveying pipeline 6 being in fluid communication with the sewage inlet of the mixing device 1 .

[0050] In a specific embodiment of the present disclosure, the system further includes a sludge conveying pipeline 10 , the inlet of the sludge conveying pipeline 10 is fluidically connected to the outlet of the settling tank 5 .

[0051] In a specific embodiment of the present disclosure, the system further includes an alkali solution delivery pipeline 18 , the outlet of the alkali solution delivery pipeline 18 is fluidically connected to the alkali inlet of the neutralization tank 4 .

[0052] The present disclosure is further illustrated below by way of examples, but the present disclosure is not limited thereby.

[0053] Example 1

[0054] exist Figure 1Wastewater is treated in a system comprising a mixing device 1, a first reactor 2, a second reactor 3, a neutralization tank 4, a settling tank 5, a first oxidant delivery pipeline 16, a second oxidant delivery pipeline 17, an acid delivery pipeline 14, a catalyst delivery pipeline 15, a first pipeline 7, a second pipeline 8 and a third pipeline 9.

[0055] The mixing device includes inlets for acid and catalyst, a wastewater inlet, and a wastewater outlet; the first reactor 2 includes a first oxidant inlet, a first water inlet, and a first water outlet; the second reactor 3 includes a second oxidant inlet, a second water inlet, and a second water outlet; the neutralization tank 4 includes an alkali inlet, a third water inlet, and a third water outlet; and the settling tank 5 includes a fourth water inlet, a fourth water outlet, and a sludge outlet. The mixing device 1, first reactor 2, second reactor 3, and neutralization tank 4 are each independently equipped with a stirring paddle.

[0056] The first pipeline includes a first main pipeline, a first branch pipeline 71 and a second branch pipeline 72. A first three-way valve 11 is provided on the first main pipeline. The inlet of the first three-way valve 11 is fluidically connected to the outlet end of the first main pipeline. The first bypass interface of the first three-way valve 11 is fluidically connected to the inlet end of the first branch pipeline 71. The outlet end of the first branch pipeline 71 is fluidically connected to the first water inlet of the first reactor. The second bypass interface of the first three-way valve is fluidically connected to the inlet end of the second branch pipeline 72. The outlet end of the second branch pipeline 72 is fluidically connected to the second water inlet of the second reactor 3.

[0057] The second pipeline 8 includes a second main pipeline, a third branch pipeline 81 and a fourth branch pipeline 82; a second three-way valve 12 and a third three-way valve 13 are provided on the second main pipeline, the first bypass interface and the inlet of the second three-way valve 12 are located on the second main pipeline, the second bypass interface of the second three-way valve 12 is fluidically connected to the inlet end of the third branch pipeline, the outlet end of the third branch pipeline is fluidically connected to the third water inlet of the neutralization tank, the first bypass interface and the inlet of the third three-way valve 13 are located on the second main pipeline, the second bypass interface of the third three-way valve 13 is fluidically connected to the inlet end of the fourth branch pipeline 82, and the outlet end of the fourth branch pipeline 82 is fluidically connected to the second water outlet of the second reactor 3.

[0058] The outlet of the first oxidant delivery pipeline 16 is fluidly connected to the first oxidant inlet of the first reactor 2, and the outlet of the second oxidant delivery pipeline 17 is fluidly connected to the second oxidant inlet of the second reactor 3; the outlet end of the acid delivery pipeline 14 is fluidly connected to the acid and catalyst inlets of the mixing device 1, and the catalyst delivery pipeline 15 is fluidly connected to the acid and catalyst inlets of the mixing device 1.

[0059] In the above system, the first reactor and the second reactor are connected in parallel to treat wastewater. The specific steps are as follows:

[0060] The wastewater is introduced into the mixing device through the wastewater inlet of the mixing device 1, and the acid and catalyst are introduced into the mixing device through the acid delivery pipeline 14 and the catalyst delivery pipeline 15 respectively. The wastewater, acid and catalyst are mixed in the mixing device, and the mixed wastewater is discharged from the wastewater outlet;

[0061] A portion of the mixed wastewater is introduced into the first reactor 2 from the first water inlet via the first main line and the first branch line 71, where it is contacted and reacted with the oxidant introduced via the first oxidant delivery line 16. The reacted wastewater is then drawn out from the first water outlet and introduced into the neutralization tank from the third water inlet via the second main line and the third branch line 81.

[0062] Another portion of the mixed wastewater is introduced into the second reactor 3 from the second water inlet via the first main line and the second branch line 71, where it is contacted with the oxidant introduced via the second oxidant delivery line 17 for reaction. The reacted wastewater is then drawn out from the second water outlet and introduced into the neutralization tank from the third water inlet via the third branch line 82, the second main line, and the third branch line 81.

[0063] The wastewater after the reaction contacts the alkali in the neutralization tank to adjust the pH value. The wastewater after the pH value is adjusted is discharged through the third pipeline 9 and then introduced into the sedimentation tank through the fourth water inlet, and is subjected to sedimentation treatment in the sedimentation tank 5. The treated wastewater is discharged from the fourth water outlet of the sedimentation tank 5, and the sludge is discharged from the sludge outlet through the sludge conveying pipeline 10.

[0064] Example 2

[0065] The same wastewater treatment system as in Example 1 is used, except that the first reactor and the second reactor are connected in series to treat the wastewater. The specific steps are as follows:

[0066] The wastewater is introduced into the mixing device through the wastewater inlet of the mixing device 1, and the acid and catalyst are introduced into the mixing device through the acid delivery pipeline 14 and the catalyst delivery pipeline 15 respectively. The wastewater, acid and catalyst are mixed in the mixing device, and the mixed wastewater is discharged from the wastewater outlet;

[0067] The entire mixed wastewater is introduced into the first reactor 2 from the sewage inlet via the first main line and the first branch line 71, where it is contacted and reacted with the oxidant introduced via the first oxidant delivery line 16. The reacted wastewater is then drawn out from the first water outlet and introduced into the second reactor via the second main line from the second water inlet. In the second reactor, the wastewater is contacted and reacted with the oxidant introduced from the second oxidant delivery line 17. The reacted wastewater is then drawn out from the second water outlet and introduced into the neutralization tank via the third branch line 82, the second main line, and the third branch line 81 from the third water inlet.

[0068] The wastewater after the reaction contacts the alkali in the neutralization tank to adjust the pH value. The wastewater after the pH value is adjusted is discharged through the third pipeline 9 and then introduced into the sedimentation tank through the fourth water inlet, and is subjected to sedimentation treatment in the sedimentation tank 5. The treated wastewater is discharged from the fourth water outlet of the sedimentation tank 5, and the sludge is discharged from the sludge outlet through the sludge conveying pipeline 10.

[0069] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings. However, the present disclosure is not limited to the specific details of the above embodiments. Within the technical concept of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all fall within the scope of protection of the present disclosure.

[0070] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0071] In addition, the various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. A wastewater treatment system, characterized in that: The wastewater treatment system comprises a mixing device (1), a first reaction kettle (2), a second reaction kettle (3), a neutralization tank (4) and a sedimentation tank (5); The mixing device (1) includes an acid and catalyst inlet, a wastewater inlet, and a wastewater outlet; the first reactor (2) includes a first oxidant inlet, a first water inlet, and a first water outlet; the second reactor (3) includes a second oxidant inlet, a second water inlet, and a second water outlet; the neutralization tank (4) includes an alkali inlet, a third water inlet, and a third water outlet; the settling tank (5) includes a fourth water inlet, a fourth water outlet, and a sludge outlet; The wastewater outlet of the mixing device (1) is in fluid communication with the first water inlet of the first reactor (2), and optionally in fluid communication with the second water inlet of the second reactor (3); The first water outlet of the first reactor (2) is switchably connected to the third water inlet of the neutralization tank (4) or the second water inlet of the second reactor (3); the second water outlet of the second reactor (3) is connected to the third water inlet of the neutralization tank (4); The third water outlet of the neutralization tank (4) is fluidically connected to the fourth water inlet of the settling tank (5).

2. The wastewater treatment system according to claim 1, characterized in that The system further comprises a first pipeline (7), a second pipeline (8) and a third pipeline (9); The first pipeline (7) is used to connect the sewage outlet of the mixing device (1) and the first sewage inlet of the first reactor (2), and optionally connect the sewage outlet of the mixing device (1) and the second sewage inlet of the second reactor (3); The second pipeline (8) is used to connect the second water outlet of the second reactor (3) and the third water inlet of the neutralization tank (4), and is switchably used to connect the first water outlet of the first reactor (2) to the third water inlet of the neutralization tank (4) or to the second water inlet of the second reactor (3); The third pipeline (9) is used to connect the third water outlet of the neutralization tank (4) and the fourth water inlet of the sedimentation tank.

3. The wastewater treatment system according to claim 2, characterized in that The first pipeline (7) comprises a first main pipeline, a first branch pipeline (71) and a second branch pipeline (72); A first three-way valve (11) is provided on the first main line, the inlet of the first three-way valve (11) is in fluid communication with the outlet of the first main line (7), the first bypass interface of the first three-way valve (11) is in fluid communication with the inlet of the first branch line (71), the outlet of the first branch line (71) is in fluid communication with the first water inlet of the first reactor (2), the second bypass interface of the first three-way valve (11) is in fluid communication with the inlet of the second branch line (72), and the outlet of the second branch line (72) is in fluid communication with the second water inlet of the second reactor (3); The second pipeline (8) includes a second main pipeline, a third branch pipeline (81) and a fourth branch pipeline (82); A second three-way valve (12) and a third three-way valve (13) are provided on the second main pipe, the first bypass interface and the inlet of the second three-way valve (12) are located on the second main pipe, the second bypass interface of the second three-way valve (12) is fluidically connected to the inlet end of the third branch pipe (81), the outlet end of the third branch pipe (81) is fluidically connected to the third water inlet of the neutralization tank (4), the first bypass interface and the inlet of the third three-way valve (13) are located on the second main pipe, the second bypass interface of the third three-way valve (13) is fluidically connected to the inlet end of the fourth branch pipe (82), and the outlet end of the fourth branch pipe (82) is fluidically connected to the second water outlet of the second reactor (3).

4. The wastewater treatment system according to claim 1, characterized in that The first water inlet of the first reactor (2) is located on the bottom side wall of the first reactor (2), and the first water outlet is located on the top side wall of the first reactor (2); The ratio of the distance between the first water inlet and the bottom surface of the first reactor to the height of the first reactor is 1:(3-100), and the ratio of the distance between the first water outlet and the bottom surface of the first reactor to the height of the first reactor is 1:(1.01-1.5).

5. The wastewater treatment system according to claim 1, characterized in that: The second water inlet of the second reactor (3) is located on the bottom side wall of the second reactor (3), and the second water outlet is located on the top side wall of the second reactor (3); The ratio of the distance between the second water inlet and the bottom surface of the second reactor to the height of the second reactor is 1:(3-100), and the ratio of the distance between the second water outlet and the bottom surface of the second reactor to the height of the second reactor is 1:(1.01-1.5).

6. The wastewater treatment system according to claim 1, characterized in that The system further comprises an acid delivery pipeline (14) and a catalyst delivery pipeline (15), wherein the outlet of the acid delivery pipeline (14) is fluidly connected to the acid and catalyst inlet of the mixing device (1), and the outlet of the catalyst delivery pipeline (14) is fluidly connected to the acid and catalyst inlet of the mixing device.

7. The wastewater treatment system according to claim 1, characterized in that The system further comprises a first oxidant delivery pipeline (16) and a second oxidant delivery pipeline (17), wherein the outlet of the first oxidant delivery pipeline (16) is fluidically connected to the first oxidant inlet of the first reactor (2), and the outlet of the second oxidant delivery pipeline (17) is fluidically connected to the second oxidant inlet of the second reactor (3).

8. The wastewater treatment system according to claim 1, characterized in that: The mixing device (1), the first reactor (2), the second reactor (3) and the neutralization tank (4) are each independently provided with a stirring mechanism.

9. The wastewater treatment system according to claim 8, characterized in that: The stirring mechanism is a stirring paddle, aeration stirring or hydraulic reflux stirring.

10. The wastewater treatment system according to claim 1, wherein: The sedimentation tank is a vertical flow sedimentation tank, a radial flow sedimentation tank or a horizontal flow sedimentation tank.

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