An electro-catalytic oxidation system for treating desulfurization wastewater

Abstract

This utility model discloses an electrocatalytic oxidation system for treating desulfurization wastewater, belonging to the field of wastewater treatment technology. The device includes: an equalization tank, a multi-media filter, a self-cleaning filter, an electrocatalytic oxidation device, a clarifier, a clear water tank, and a plate and frame filter press, arranged sequentially along the flow direction of the desulfurization wastewater. The outlet of the equalization tank is connected to the top inlet of the multi-media filter; the bottom outlet of the multi-media filter is connected to the inlet of the self-cleaning filter; and the outlet of the self-cleaning filter is connected to the inlet of the electrocatalytic oxidation device. This utility model, by setting up the equalization tank, multi-media filter, self-cleaning filter, electrocatalytic oxidation device, clarifier, clear water tank, and plate and frame filter press, achieves compliant discharge of desulfurization wastewater. Compared with zero-discharge wastewater processes, it saves on equipment investment and operating costs, while also saving land area, effectively combining social and economic value.

Description

Technical Field

[0001] This utility model relates to the field of wastewater treatment technology, specifically to an electrocatalytic oxidation system for treating desulfurization wastewater. Background Technology

[0002] With the rapid development of high-tech such as AI, big data, and high computing power, the demand for stable electricity is becoming increasingly strong. The desulfurization wastewater generated by the limestone-gypsum wet desulfurization technology used in coal-fired power plants generally has characteristics such as high salt, high COD, high SS, and high heavy metals. In some power plants, ammonia escape caused by excessive ammonia injection at the front end of the denitrification process can also lead to excessive ammonia nitrogen in the desulfurization wastewater. The traditional three-stage process of flocculation, sedimentation, and clarification can only solve the problem of excessive SS and heavy metals, but cannot solve the problem of excessive COD and ammonia nitrogen.

[0003] Zero-discharge technologies for wastewater treatment using evaporation crystallization or membrane concentration are not adopted by some power plants due to high investment and operating costs and large land area requirements. Therefore, electrocatalytic oxidation technology can combine the advantages of both processes. By generating hydroxyl radicals (·OH) and active chlorine through the anode plate, it can directly or indirectly oxidize reducing inorganic salts, organic matter, and ammonia nitrogen, while reducing the chloride ion content in the solution. Ultimately, this can ensure that desulfurization wastewater meets the discharge standards. Utility Model Content

[0004] The purpose of this invention is to provide an electrocatalytic oxidation system for treating desulfurization wastewater. This system uses electrocatalytic oxidation, flocculation, sedimentation, and filtration to reduce the suspended solids (SS), carbon dioxide (COD), and ammonia nitrogen (AM) in the wastewater, ultimately ensuring that the desulfurization wastewater meets discharge requirements. This effectively combines social and economic value.

[0005] To solve the above-mentioned technical problems, this utility model provides an electrocatalytic oxidation system for treating desulfurization wastewater, including an equalization tank, a multi-media filter, a self-cleaning filter, an electrocatalytic oxidation device, a clarifier, a clear water tank, and a plate and frame filter press arranged sequentially along the flow direction of the desulfurization wastewater;

[0006] The outlet of the equalization tank is connected to the top inlet of the multi-media filter;

[0007] The bottom outlet of the multi-media filter is connected to the inlet of the self-cleaning filter;

[0008] The multi-media filter contains, from bottom to top, a pebble filter layer, a quartz sand filter layer, and an activated carbon filter layer.

[0009] The outlet of the self-cleaning filter is connected to the inlet of the electrocatalytic oxidation equipment;

[0010] The outlet of the electrocatalytic oxidation device is connected to the inlet of the clarifier;

[0011] The overflow port of the clarifier is connected to the clear water tank, and the sludge discharge port of the clarifier is connected to the plate and frame filter press.

[0012] Preferably, the particle size range of the pebble filter layer is 0.2–0.4 mm;

[0013] The particle size range of the quartz sand filter layer is 0.4–0.8 mm;

[0014] The particle size range of the activated carbon filter layer is 0.8 to 2 mm.

[0015] Preferably, the filtration accuracy of the self-cleaning filter is 5–10 μm.

[0016] Preferably, the electrocatalytic oxidation device has a water inlet at the top of one side and a water outlet at the bottom of the other side;

[0017] The electrocatalytic oxidation device is equipped with multiple sets of anode and cathode plates. The anode of the anode and cathode plates is made of boron-doped diamond with graphene coating, and the cathode plates are made of titanium. The distance between the plates is 4-10 mm.

[0018] Preferably, the dosing port of the clarifier is connected to the coagulant storage tank;

[0019] The coagulant storage tank contains a coagulant PAM concentration of 0.1-0.2%.

[0020] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0021] This utility model achieves the standard discharge of desulfurization wastewater by setting up an equalization tank, a multi-media filter, a self-cleaning filter, an electrocatalytic oxidation device, a clarifier, a clear water tank, and a plate and frame filter press. Compared with the zero-discharge wastewater process, it saves the investment and operating costs of the equipment, and also saves the land area, thus achieving an effective combination of social and economic value. Attached Figure Description

[0022] The specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings.

[0023] Figure 1 This is a schematic diagram of the structure of an electrocatalytic oxidation system for treating desulfurization wastewater according to the present invention.

[0024] In the picture:

[0025] 1. Equalization tank; 2. Multi-media filter; 21. Pebble filter layer; 22. Quartz sand filter layer; 23. Activated carbon filter layer; 3. Self-cleaning filter; 4. Electrocatalytic oxidation equipment; 5. Clarifier; 6. Clear water tank; 7. Plate and frame filter press. Detailed Implementation

[0026] Many specific details are set forth in the following description to provide a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0027] The terminology used in one or more embodiments of this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the one or more embodiments of this specification. The singular forms “a,” “described,” and “the” as used in one or more embodiments of this specification and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used in one or more embodiments of this specification refers to and includes any or all possible combinations of one or more associated listed items.

[0028] It should be understood that although the terms first, second, etc., may be used to describe various information in one or more embodiments of this specification, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, first may also be referred to as second without departing from the scope of one or more embodiments of this specification, and similarly, second may also be referred to as first. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to a determination."

[0029] The present invention will now be described in further detail with reference to the accompanying drawings:

[0030] This utility model discloses an electrocatalytic oxidation system for treating desulfurization wastewater, including an equalization tank 1, a multi-media filter 2, a self-cleaning filter 3, an electrocatalytic oxidation device 4, a clarifier 5, a clear water tank 6, and a plate and frame filter press 7 arranged sequentially along the flow direction of the desulfurization wastewater.

[0031] As a further improvement of this utility model, the regulating tank 1 is connected to the wastewater hydrocyclone of the gypsum dewatering system, mainly serving to homogenize and equalize the flow. The filter media in the multi-media filter 2 connected at the rear end include, from bottom to top, a pebble filter layer 21, a quartz sand filter layer 22, and an activated carbon filter layer 23.

[0032] As a further improvement of this utility model, the self-cleaning filter 3 is made of 2205 duplex steel with a filtration accuracy of 5-10μm, which can remove most suspended solids. The reverse self-cleaning system is triggered when the pressure difference between the inside and outside of the filter reaches a set value.

[0033] As a further improvement of this utility model, the water inlet at the upper end of the electrocatalytic oxidation device 4 is connected to the self-cleaning filter at the front end. The device adopts a module with multiple sets of anode and cathode plates. The anode is made of boron-doped diamond with graphene coating, and the cathode plate is made of titanium. The water outlet at the lower end of the electrocatalytic oxidation device 4 is connected to the clarifier 5 at the rear end.

[0034] As a further improvement of this utility model, the supernatant at the overflow port of the clarifier 5 is connected to the clear water tank 6 at the rear end, and the sludge discharge port of the sludge concentration zone at the bottom is filtered by a plate and frame filter press 7.

[0035] This utility model discloses an electrocatalytic oxidation system for treating desulfurization wastewater, comprising an equalization tank 1, a multi-media filter 2, a self-cleaning filter 3, an electrocatalytic oxidation device 4, a clarifier 5, a clear water tank 6, and a plate and frame filter press 7, arranged sequentially along the flow direction of the desulfurization wastewater. This utility model, targeting the electrochemical treatment system for wet desulfurization wastewater, mainly employs electrocatalytic oxidation, flocculation, sedimentation, and filtration to reduce the suspended solids (SS), carbon dioxide (COD), and ammonia nitrogen (AM) of the wastewater, ultimately achieving the discharge requirements of the "Water Quality Control Index for Limestone-Gypsum Wet Desulfurization Wastewater from Coal-fired Power Plants" (DLT 997—2020), thus effectively combining social and economic value.

[0036] To better illustrate the technical effects of this utility model, the present utility model provides the following specific embodiments to explain the above technical process:

[0037] Example 1: An electrocatalytic oxidation system for treating desulfurization wastewater, such as... Figure 1 As shown, the system includes an equalization tank 1, a multi-media filter 2, a self-cleaning filter 3, an electrocatalytic oxidation device 4, a clarifier 5, a clear water tank 6, and a plate and frame filter press 7. It primarily employs electrocatalytic oxidation, flocculation, sedimentation, and filtration to reduce the suspended solids (SS), carbon dioxide (COD), and ammonia nitrogen (AMN) in the wastewater. Ultimately, the desulfurization wastewater meets the discharge requirements of the "Water Quality Control Index for Limestone-Gypsum Wet Desulfurization Wastewater from Coal-fired Power Plants" (DLT 997—2020), effectively combining social and economic value.

[0038] In this embodiment, the TDS of the desulfurization wastewater typically exceeds 50,000 mg / L, and the main cation is Ca. 2+ Mg 2+ Fe 3+ Na + NH 4+ The plasma, with SO4 as the main anion. 2- and Cl - and a small amount of NO 3-The pollutants exceeding the standards mainly include suspended solids (SS), COD, ammonia nitrogen, heavy metals, and fluorides. Traditional three-stage processes involving flocculation, sedimentation, and clarification can only address SS and heavy metal exceedances, but not COD and ammonia nitrogen exceedances. Electrocatalytic oxidation technology generates hydroxyl radicals (·OH) and active chlorine through the anode plate, which can directly or indirectly oxidize reducing inorganic salts, organic matter, and ammonia nitrogen. Simultaneously, it reduces the chloride ion content in the solution, ultimately enabling desulfurization wastewater to meet discharge standards.

[0039] like Figure 1 As shown in the above embodiment, the system includes an equalization tank 1, a multi-media filter 2, a self-cleaning filter 3, an electrocatalytic oxidation device 4, a clarifier 5, a clear water tank 6, and a plate and frame filter press 7 arranged sequentially along the flow direction of the desulfurization wastewater.

[0040] In the above embodiment, the equalization tank 1 connects to the wastewater hydrocyclone of the gypsum dewatering system, mainly serving to homogenize and equalize the flow. The multi-media filter 2 connected at the rear end contains, from bottom to top, a pebble filter layer 21, a quartz sand filter layer 22, and an activated carbon filter layer 23, primarily removing suspended solids and large organic particles. The pebble filter layer 21 has a relatively high density, with a particle size range of 0.2–0.4 mm. The middle quartz sand filter layer 22 is composed of quartz sand with a particle size range of 0.4–0.8 mm. The top activated carbon filter layer 23 is composed of activated carbon with a relatively low density and a relatively large particle size range of 0.8–2 mm. The effluent from the multi-media filter is connected to a self-cleaning filter 3. The self-cleaning filter 3 is made of 2205 duplex steel, with a filtration accuracy of 5–10 μm, capable of removing most suspended solids. A reverse self-cleaning system is triggered when the pressure difference between the inside and outside of the filter reaches a set value.

[0041] In the above embodiment, the inlet at the upper end of the electrocatalytic oxidation device 4 is connected to the self-cleaning filter 3 at the front end. The device adopts a module with multiple sets of composite anode and cathode plates. The anode is made of boron-doped diamond with graphene coating, and the cathode plate is made of titanium. The voltage is set to 4-10V, the current is set to 20-30A, and the electrode spacing is 4-10mm. The outlet at the lower end of the electrocatalytic oxidation device 4 is connected to the clarifier 5 at the rear end.

[0042] In the above embodiment, the supernatant at the overflow port of the clarifier 5 is connected to the clear water tank 6 at the rear end, and the sludge discharge port of the sludge thickening zone at the bottom is filtered by a plate and frame filter press 7. When the sludge settling effect does not meet the requirements, a coagulant aid PAM can be added to the clarifier through the dosing port. The concentration of the coagulant aid PAM is preferably 0.1-0.2%.

[0043] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any changes or substitutions within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

Claims

1. An electrocatalytic oxidation system for treating desulfurization wastewater, characterized in that: The system includes an equalization tank (1), a multi-media filter (2), a self-cleaning filter (3), an electrocatalytic oxidation device (4), a clarifier (5), a clear water tank (6), and a plate and frame filter press (7) arranged sequentially along the flow direction of the desulfurization wastewater. The outlet of the regulating tank (1) is connected to the top inlet of the multi-media filter (2); The bottom outlet of the multi-media filter (2) is connected to the inlet of the self-cleaning filter (3); The multi-media filter (2) is provided with a pebble filter layer (21), a quartz sand filter layer (22) and an activated carbon filter layer (23) arranged from bottom to top. The outlet of the self-cleaning filter (3) is connected to the inlet of the electrocatalytic oxidation device (4); The outlet of the electrocatalytic oxidation device (4) is connected to the inlet of the clarifier (5); The overflow port of the clarifier (5) is connected to the clear water tank (6), and the sludge discharge port of the clarifier (5) is connected to the plate and frame filter press (7).

2. The electrocatalytic oxidation system for treating desulfurization wastewater according to claim 1, characterized in that: The particle size range of the pebble filter layer (21) is 0.2 to 0.4 mm; The particle size range of the quartz sand filter layer (22) is 0.4 to 0.8 mm; The particle size range of the activated carbon filter layer (23) is 0.8 to 2 mm.

3. The electrocatalytic oxidation system for treating desulfurization wastewater according to claim 2, characterized in that: The self-cleaning filter (3) has a filtration accuracy of 5-10 μm.

4. The electrocatalytic oxidation system for treating desulfurization wastewater according to claim 3, characterized in that: The electrocatalytic oxidation device (4) has a water inlet on the top of one side and a water outlet on the bottom of the other side. The electrocatalytic oxidation device (4) is equipped with multiple sets of anode and cathode plates. The anode of the anode and cathode plates is made of boron-doped diamond with graphene coating, and the cathode plates of the anode and cathode plates are made of titanium. The distance between the plates is 4 to 10 mm.

5. The electrocatalytic oxidation system for treating desulfurization wastewater according to claim 4, characterized in that: The dosing port of the clarifier (5) is connected to the coagulant storage tank; The coagulant storage tank contains a coagulant PAM concentration of 0.1-0.2%.

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