Zero-discharge treatment method for desulfurization wastewater

Abstract

The present invention relates to the field of wastewater treatment, and in particular to a method for treating desulfurization wastewater with zero discharge, the method comprising: step S1, treating desulfurization wastewater to obtain pre-treated wastewater; step S2, injecting the pre-treated wastewater into an electrocatalytic Fenton cell, reacting in a first time period under the condition that the hydrogen peroxide production rate is the largest, and obtaining the first treated wastewater; step S3, injecting the first treated wastewater into an electrochemical oxidation cell, reacting in a second time period under the condition that the ferrous ion production rate is the largest, and obtaining the second treated wastewater; step S4, obtaining the fifth treated wastewater by the number of reaction processes of the electrocatalytic Fenton cell and the electrochemical oxidation cell of the first calculated value; step S5, injecting the fifth treated wastewater into the first treatment tank for chloride ion detection, and recycling or electrolytically treating the fifth treated wastewater. The present invention improves the removal efficiency of COD in wastewater through two process reactions of the electrocatalytic Fenton cell and the electrochemical oxidation cell.

Description

Technical Field

[0001] The invention relates to the field of wastewater treatment, and in particular to a zero-discharge treatment method for desulfurization wastewater. Background Art

[0002] Wastewater treatment is a key technology in human history. With the rapid development of urbanization and industrialization, the problem of wastewater discharge has become increasingly prominent. Untreated sewage will bring many environmental and health problems, such as water pollution, soil pollution and disease transmission. Analyzing the development history of sewage treatment at home and abroad, combined with the current development status of my country, the report of the 18th National Congress pointed out: to build an ecological civilization, chemical companies are transforming towards green development, efficient development and low-carbon development. We should increase the intensity and requirements of pollution control, actively research innovative technologies while constantly absorbing advanced sewage treatment technologies from abroad, so that my country can have sewage treatment technologies suitable for itself.

[0003] Patent document with publication number CN103539296A discloses a method and device for treating high-concentration biodegradable organic wastewater, which comprises: ① adjusting the pH value of the wastewater to 3; ② sending the adjusted wastewater into a Fenton reactor, adding Fenton reagent at the same time, and causing Fenton reaction; ③ passing the wastewater containing Fenton reagent through an electric flocculation device, and continuing to cause Fenton reaction under the action of the electric field of a pulse power supply, while also causing electrochemical reaction and electrocatalytic oxidation reaction, the reaction further degrades organic matter in the wastewater, and generates floccules and precipitates; the floccules are scraped off by a scraper arranged in the flotation zone of the electric flocculation device; ④ the wastewater with precipitate flows into a sedimentation tank, and the pH value is adjusted to 7-8, and the precipitated wastewater is discharged to the sedimentation tank.

[0004] In the prior art, during the electrocatalytic Fenton and electrochemical oxidation processes for treating wastewater, the reaction efficiency is low, resulting in the problem of low COD removal efficiency in the wastewater. Summary of the invention

[0005] To this end, the present invention provides a zero-discharge treatment method for desulfurization wastewater, which can solve the problem of low COD removal efficiency in wastewater.

[0006] To achieve the above object, the present invention provides a method for zero-discharge treatment of desulfurization wastewater, comprising: step S1, filtering and standing the desulfurization wastewater to obtain pretreated wastewater;

[0007] Step S2, injecting the pretreated wastewater into the electrocatalytic Fenton cell, adjusting the angle of the stacked membrane cathode plate in the electrocatalytic Fenton cell from any angle to the first optimal angle according to a first optimal angle obtained in a preset first test cycle, so that the rate of hydrogen peroxide generated in the electrocatalytic Fenton cell is maximized, and obtaining first treated wastewater after the pretreated wastewater reacts in the electrocatalytic Fenton cell for a second period of time;

[0008] Step S3, injecting the first treated wastewater into the electrochemical oxidation tank, adjusting the angle of the laminated anode plate in the electrochemical oxidation tank from any angle to the second optimal angle according to the second optimal angle obtained in the preset second test cycle, so as to maximize the rate of ferrous ions generated in the electrochemical oxidation tank, and obtaining second treated wastewater when the second ferrous ion data in the first treated wastewater is the same as the second standard ferrous ion data;

[0009] Step S4, injecting the second treated wastewater into the electrocatalytic Fenton cell to obtain third treated wastewater, injecting the third treated wastewater into an electrochemical oxidation cell for reaction to obtain fourth treated wastewater, calculating the number of reaction processes of the electrocatalytic Fenton cell and the electrochemical oxidation cell according to the COD content in the wastewater, taking the calculated result as the first calculated value, and obtaining fifth treated wastewater after the fourth treated wastewater undergoes the reaction process of the first calculated value;

[0010] Step S5, injecting the fifth treated wastewater into the first treatment tank through the electrodialysis membrane for chloride ion detection, if the chloride ion concentration is less than the chloride ion emission standard concentration, the fifth treated wastewater is recycled as the final treated wastewater, if the chloride ion concentration is greater than or equal to the chloride ion emission standard concentration, the fifth treated wastewater is electrolyzed.

[0011] Further, the first optimal angle obtained according to the preset first test cycle includes:

[0012] Setting a first initial angle of the stacked film cathode plate in the electrocatalytic Fenton cell, dividing the angle of the stacked film cathode plate from the first initial angle to the first limit angle of the stacked film cathode plate, and obtaining a plurality of first angles, wherein the stacked film cathode plate rotates from the first initial angle to the first limit angle of the stacked film cathode plate as the first test cycle;

[0013] Detecting the hydrogen peroxide rates generated at the first angles in the same time period to obtain a plurality of first detection data;

[0014] A plurality of the first detection data are sorted and output as a first sequence, the data sorted first in the first sequence is used as a first hydrogen peroxide rate, and the angle corresponding to the first hydrogen peroxide rate is used as a first optimal angle.

[0015] Further, obtaining the first treated wastewater includes:

[0016] Injecting the pretreated wastewater into the electrocatalytic Fenton cell, and detecting the COD content in the pretreated wastewater as a first COD content;

[0017] Turning on the power supply of the electrocatalytic Fenton cell, adjusting the angle of the laminated film cathode plate in the electrocatalytic Fenton cell from any angle to the first optimal angle, performing real-time detection on the hydrogen peroxide content generated by the laminated film cathode plate in the electrocatalytic Fenton cell, and obtaining a plurality of detection data as a plurality of first hydrogen peroxide data;

[0018] Performing real-time detection on the ferrous ion content generated on the stacked membrane anode plate in the electrocatalytic Fenton cell, and obtaining a plurality of detection data as a plurality of first ferrous ion data;

[0019] A ratio calculation is performed on a number of the first ferrous ion data and a number of the first hydrogen peroxide data to obtain a number of first ratios. When the first ratios are the same as the first standard ratios, the power supply of the electrocatalytic Fenton cell is turned off, and the first treated wastewater is obtained after a reaction in a first time period.

[0020] Further, the second optimal angle obtained according to the preset second test cycle includes:

[0021] Setting a second initial angle of the laminated film anode plate in the electrochemical oxidation cell, dividing the angle of the laminated film anode plate from the second initial angle to the second limit angle of the laminated film anode plate, and obtaining a plurality of second angles, wherein the first test cycle is the angle from the second initial angle to the second limit angle of the laminated film anode plate;

[0022] Detecting the ferrous ion rates generated at the plurality of second angles in the same time period to obtain a plurality of second detection data;

[0023] A plurality of the second detection data are sorted and output as a second sequence, the first-ranked data in the second sequence is used as the first ferrous ion rate, and the angle corresponding to the first ferrous ion rate is used as the second optimal angle.

[0024] Further, when the second ferrous ion data in the first treated wastewater is the same as the second standard ferrous ion data, obtaining the second treated wastewater includes:

[0025] injecting the first treated wastewater into the electrochemical oxidation tank, and turning on the power supply of the electrochemical oxidation tank;

[0026] The angle of the laminated anode plate in the electrochemical oxidation tank is adjusted from any angle to the second optimal angle, the content of ferrous ions generated in the electrochemical oxidation is detected in real time, and a plurality of detection data are obtained as a plurality of second ferrous ion data;

[0027] When the second ferrous ion data are equal to the second standard ferrous ion data, the power supply of the electrochemical oxidation tank is turned off, and the second treated wastewater is obtained after a reaction in a second time period;

[0028] The COD content of the second treated wastewater is detected as a second COD content.

[0029] Further, injecting the second treated wastewater into the electrocatalytic Fenton cell to obtain the third treated wastewater comprises:

[0030] injecting the second treated wastewater into the electrocatalytic Fenton cell, and turning on the power supply of the electrocatalytic Fenton cell;

[0031] detecting a rate of hydrogen peroxide generated by the laminated film cathode plate in the electrocatalytic Fenton cell as a second hydrogen peroxide rate, and when the second hydrogen peroxide rate is greater than or equal to the first hydrogen peroxide rate, not adjusting the angle of the laminated film cathode plate in the electrocatalytic Fenton cell; and when the second hydrogen peroxide rate is less than the first hydrogen peroxide rate, adjusting the angle of the laminated film cathode plate in the electrocatalytic Fenton cell within a first angle range, detecting the hydrogen peroxide rate within the first angle range, acquiring a plurality of third detection data, taking the angle of the laminated film cathode plate corresponding to the maximum value among the plurality of third detection data as a third optimal angle, and adjusting the laminated film cathode plate from the first optimal angle to the third optimal angle;

[0032] The hydrogen peroxide content generated by the stacked membrane cathode plate in the electrocatalytic Fenton cell is monitored in real time, and a plurality of detection data are obtained as a plurality of second hydrogen peroxide data; the ferrous ion content generated by the stacked membrane anode plate in the electrocatalytic Fenton cell is detected in real time, and a plurality of detection data are obtained as a plurality of third ferrous ion data;

[0033] A ratio calculation is performed on a number of the third ferrous ion data and a number of the second hydrogen peroxide data to obtain a number of second ratios. When the second ratio is the same as the second standard ratio, the power supply of the electrocatalytic Fenton cell is turned off, and the third treated wastewater is obtained after a reaction in a first time period.

[0034] Further, injecting the third treated wastewater into an electrochemical oxidation tank for reaction to obtain fourth treated wastewater comprises:

[0035] injecting the third treated wastewater into the electrochemical oxidation tank, and turning on the power supply of the electrochemical oxidation tank;

[0036] Detecting the rate of ferrous ions generated by the laminated film anode plate in the electrochemical oxidation cell as a second ferrous ion rate, when the second ferrous ion rate is greater than or equal to the first ferrous ion rate, not adjusting the angle of the laminated film anode plate in the electrochemical oxidation cell, and when the second ferrous ion rate is less than the first ferrous ion rate, adjusting the angle of the laminated film anode plate in the electrochemical oxidation cell within a second angle range, detecting the ferrous ion rate within the second angle range, acquiring a plurality of fourth detection data, taking the angle of the laminated film anode plate corresponding to the maximum value among the plurality of the fourth detection data as a fourth optimal angle, and adjusting the laminated film anode plate from the second optimal angle to the third optimal angle;

[0037] Real-time detection of the ferrous ion content generated in the electrochemical oxidation tank, and acquisition of a number of detection data as a number of fourth ferrous ion data;

[0038] When some of the fourth ferrous ion data are equal to the third standard ferrous ion data, turning off the power supply of the electrochemical oxidation tank, and obtaining the fourth treated wastewater after a reaction in a second time period;

[0039] The COD content of the fourth treated wastewater is detected as the third COD content.

[0040] Further, after the fourth treated wastewater undergoes a reaction process of the first calculated value, obtaining the fifth treated wastewater comprises:

[0041] Calculate the number of reaction processes through the electrocatalytic Fenton cell and the electrochemical oxidation cell by using the first COD content, the second COD content, the third COD content and the standard COD content, and use the calculation result as a first calculated value;

[0042] The COD content in the wastewater obtained after the reaction of the electrocatalytic Fenton cell and the electrochemical oxidation cell according to the first calculated value is detected as the fourth COD content. If the fourth COD content is less than or equal to the emission standard COD content, a first reaction result is obtained after the reaction of the electrocatalytic Fenton cell and the electrochemical oxidation cell for the first calculated value times, and the first reaction result is the fifth treated wastewater. If the fourth COD content is greater than the emission standard COD content, after the reaction of the electrocatalytic Fenton cell and the electrochemical oxidation cell according to the first calculated value, a second reaction result is obtained after the reaction of the electrocatalytic Fenton cell and the electrochemical oxidation cell is performed again, and the second reaction result is the fifth treated wastewater.

[0043] Further, electrolytic treatment of the fifth treated wastewater includes:

[0044] injecting the fifth treated wastewater into a second treatment tank;

[0045] The power supply of the second treatment tank is turned on, the chlorine gas generated by the anode of the second treatment tank is collected by the first collecting device, and the sodium hypochlorite generated by the cathode of the second treatment tank is discharged to the second collecting device through a pipeline.

[0046] Furthermore, it also includes, after the fifth treated wastewater is electrolytically treated, discharging the sodium hypochlorite solution arranged in the second collecting device into the electrocatalytic Fenton cell and the electrochemical oxidation cell to achieve disinfection of the electrocatalytic Fenton cell and the electrochemical oxidation cell.

[0047] Compared with the prior art, the beneficial effect of the present invention is that by filtering and standing the desulfurized wastewater, the solid impurities and sediments in the desulfurized wastewater are removed, the influence of the reaction in the subsequent reaction process is reduced, and the accuracy of the subsequent reaction is improved. By adjusting the angle of the laminated cathode plate in the electrocatalytic Fenton cell from any angle to the first optimal angle, the rate of hydrogen peroxide generated by the laminated cathode plate in the electrocatalytic Fenton cell is maximized, the rate at which the ferrous ions generated by the laminated anode plate in the electrocatalytic Fenton cell react with the hydrogen peroxide is increased, the efficiency of the ferrous ions and the hydrogen peroxide to produce hydroxyl radicals is increased, the mineralization efficiency of the organic matter in the pretreated wastewater is improved, the COD removal rate is greatly improved, and the pretreated wastewater reacts in the electrocatalytic Fenton cell. In the second time period, the organic matter in the pretreated wastewater is fully mineralized, and the angle of the stacked membrane anode plate in the electrochemical oxidation tank is adjusted from any angle to the second optimal angle, so that the rate of ferrous ions generated in the electrochemical oxidation tank is maximized, the complex generated in the electrocatalytic Fenton cell is mineralized, and the ferrous ions are released, which greatly improves the recycling of ferrous ions and the removal rate of COD. The fifth treated wastewater is obtained after the reaction process of the first calculated value, so that it is predicted whether the treated wastewater meets the emission standard, which saves process time and improves process efficiency. The fifth treated wastewater is injected into the first treatment tank through the electrodialysis membrane for chloride ion detection, so that the fifth treated wastewater is subjected to chloride ion removal, the standard of zero emission of desulfurization wastewater is met, and the recycling of desulfurization wastewater is realized.

[0048] In particular, by setting the first initial angle of the stacked film cathode plate in the electrocatalytic Fenton cell, the measurement target is clear at the beginning of the measurement, and by dividing the angle of the stacked film cathode plate from the first initial angle to the first limit angle of the stacked film cathode plate, the measurement is simple and clear, and the detection efficiency is improved. By detecting the hydrogen peroxide rates generated by several first angles in the same time period, several first detection data results obtained from the hydrogen peroxide rate detection at different angles are accurate. By sorting several first detection data, the values ​​of the first detection data are clear, and it is convenient to extract the maximum value, which improves the efficiency of obtaining the first optimal angle.

[0049] In particular, by detecting the COD content in the pretreated wastewater, the initial COD content of the pretreated wastewater is recorded to provide reference data for the subsequent wastewater treatment process. By adjusting the angle of the stacked membrane cathode plate in the electrocatalytic Fenton cell from any angle to the first optimal angle, the generation rate of the hydrogen peroxide is maximized, the reaction process rate with ferrous ions is increased, the efficiency of mineralization of organic matter in the wastewater is improved, and the removal efficiency of COD in the wastewater is accelerated. When the first ratio is the same as the first standard ratio, the power supply of the electrocatalytic Fenton cell is turned off to allow ferrous ions and hydrogen peroxide to react to saturation, thereby avoiding the generation of other impurities during the reaction while the power is always on. The first treated wastewater is obtained through the reaction in the first time period, so that the hydroxyl radicals generated by the reaction of hydrogen peroxide and ferrous ions completely decompose the organic matter in the pretreated wastewater, thereby improving the removal rate of COD in the wastewater.

[0050] In particular, by setting the second initial angle of the laminated membrane anode plate in the electrochemical oxidation cell, the initial target is clear during the measurement process, which is convenient for subsequent measurements. By rotating the laminated membrane anode plate from the second initial angle to the second extreme angle of the laminated membrane anode plate and performing angle division, the measurement result is comprehensive, the measurement process is simple and clear, and the detection rate is improved. By detecting the ferrous ion rates generated by several second angles in the same time period, the ferrous ion rate data measured at different angles are accurate. By sorting several second detection data, the second detection data are clear, which saves the time for extracting the maximum value in the second detection data and improves the efficiency of obtaining the second optimal angle.

[0051] In particular, by injecting the second treated wastewater into the electrochemical oxidation tank and turning on the power of the electrochemical oxidation tank, the complex produced in the electrocatalytic Fenton tank is mineralized and the ferrous ions are released, thereby greatly improving the recycling of ferrous ions and the COD removal rate. By adjusting the angle of the stacked membrane anode plate in the electrochemical oxidation tank from any angle to the second optimal angle, the efficiency of the ferrous ions produced in the electrochemical oxidation tank is the highest. Through the reaction in the second time period, the complex produced in the electrocatalytic Fenton tank is completely mineralized and the ferrous ions are completely released. By detecting the second COD content, the COD content in the second treated wastewater after the reaction between the electrocatalytic Fenton tank and the electrochemical oxidation tank is recorded, providing a calculation data basis for the subsequent calculation of the number of treatment processes that the wastewater needs to undergo.

[0052] In particular, by detecting the rate of hydrogen peroxide generated by the stacked membrane cathode plate in the electrocatalytic Fenton cell, it is determined whether to adjust the first optimal angle so that the rate of hydrogen peroxide generated in the electrocatalytic Fenton cell is maximized during the process of obtaining the third treated wastewater, thereby increasing the rate of the reaction process with ferrous ions, thereby increasing the efficiency of mineralization of organic matter in the wastewater, and accelerating the removal efficiency of COD in the wastewater. The third treated wastewater is obtained through the reaction in the first time period, so that the hydroxyl radicals generated by the reaction of hydrogen peroxide and ferrous ions can completely decompose the organic matter in the pretreated wastewater, thereby increasing the removal rate of COD in the wastewater.

[0053] In particular, by detecting the rate of ferrous ions generated by the stacked membrane anode plate in the electrochemical oxidation cell, it is determined whether to adjust the second optimal angle so that the rate of obtaining ferrous ions in the electrochemical oxidation cell is the fastest, thereby improving the COD removal efficiency in the wastewater. Through the reaction in the second time period, the complex produced in the electrocatalytic Fenton cell is completely mineralized and the ferrous ions are completely released. By detecting the third COD content, the COD content in the fourth treated wastewater after two reactions in the electrocatalytic Fenton cell and the electrochemical oxidation cell is recorded, providing a calculation data basis for the subsequent calculation of the number of treatment processes that the wastewater needs to undergo.

[0054] In particular, the number of reaction processes through the electrocatalytic Fenton cell and the electrochemical oxidation cell is calculated by the first COD content, the second COD content, the third COD content and the standard COD content, so that it is predicted whether the treated wastewater meets the discharge standard, which saves process time and improves process efficiency. By detecting the fourth COD content, it is determined whether the wastewater meets the discharge standard. If not, the above process is performed again to complete the mineralization of organic matter in the wastewater, meet the discharge standard, and protect environmental resources.

[0055] In particular, by collecting the chlorine gas generated by the anode of the second treatment tank through the first collecting device and discharging the sodium hypochlorite generated by the cathode of the second treatment tank to the second collecting device through a pipeline, the desulfurization wastewater can be reused, thereby saving waste of resources and solving the problem of continuous corrosion of equipment caused by high concentration of chloride ions.

[0056] In particular, by discharging the sodium hypochlorite solution arranged in the second collecting device into the electrocatalytic Fenton cell and the electrochemical oxidation cell, the electrocatalytic Fenton cell and the electrochemical oxidation cell are disinfected, thereby realizing the recovery and comprehensive utilization of desulfurization wastewater. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 A schematic diagram of a process for zero-discharge treatment of desulfurization wastewater provided by an embodiment of the present invention;

[0058] Figure 2 A schematic diagram of a process for obtaining first treated wastewater in a zero-discharge treatment method for desulfurization wastewater provided by an embodiment of the present invention;

[0059] Figure 3 A schematic diagram of a process for obtaining second treated wastewater in a zero-discharge treatment method for desulfurization wastewater provided by an embodiment of the present invention;

[0060] Figure 4 A schematic flow chart of electrolyzing the fifth treated wastewater in a method for zero-discharge treatment of desulfurization wastewater provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0061] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0062] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0063] It should be noted that, in the description of the present invention, terms such as "up", "down", "left", "right", "inside" and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings. This is merely for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0064] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0065] See also Figure 1 As shown, the present invention provides a zero-discharge treatment method for desulfurization wastewater, the method comprising: step S1, filtering and standing the desulfurization wastewater to obtain pretreated wastewater;

[0066] Step S2, injecting the pretreated wastewater into the electrocatalytic Fenton cell, adjusting the angle of the stacked membrane cathode plate in the electrocatalytic Fenton cell from any angle to the first optimal angle according to a first optimal angle obtained in a preset first test cycle, so that the rate of hydrogen peroxide generated in the electrocatalytic Fenton cell is maximized, and obtaining first treated wastewater after the pretreated wastewater reacts in the electrocatalytic Fenton cell for a second period of time;

[0067] Step S3, injecting the first treated wastewater into the electrochemical oxidation tank, adjusting the angle of the laminated anode plate in the electrochemical oxidation tank from any angle to the second optimal angle according to the second optimal angle obtained in the preset second test cycle, so as to maximize the rate of ferrous ions generated in the electrochemical oxidation tank, and obtaining second treated wastewater when the second ferrous ion data in the first treated wastewater is the same as the second standard ferrous ion data;

[0068] Step S4, injecting the second treated wastewater into the electrocatalytic Fenton cell to obtain third treated wastewater, injecting the third treated wastewater into an electrochemical oxidation cell for reaction to obtain fourth treated wastewater, calculating the number of reaction processes of the electrocatalytic Fenton cell and the electrochemical oxidation cell according to the COD content in the wastewater, taking the calculated result as the first calculated value, and obtaining fifth treated wastewater after the fourth treated wastewater undergoes the reaction process of the first calculated value;

[0069] Step S5, injecting the fifth treated wastewater into the first treatment tank through the electrodialysis membrane for chloride ion detection, if the chloride ion concentration is less than the chloride ion emission standard concentration, the fifth treated wastewater is recycled as the final treated wastewater, if the chloride ion concentration is greater than or equal to the chloride ion emission standard concentration, the fifth treated wastewater is electrolyzed.

[0070] Specifically, COD is an important and rapidly measurable organic pollution parameter in the study of river pollution and industrial wastewater properties and the operation and management of wastewater treatment plants.

[0071] Filtering and standing the desulfurization wastewater includes: passing the desulfurization wastewater through a first filter screen to obtain first desulfurization wastewater;

[0072] injecting the first desulfurized wastewater into a static tank, and removing the sediment in the first desulfurized wastewater after a first period of time, to obtain second desulfurized wastewater;

[0073] injecting the second desulfurized wastewater into an air flotation tank, and removing grease from the second desulfurized wastewater by injecting air to obtain third desulfurized wastewater;

[0074] Passing the third desulfurization wastewater through a second filter screen to obtain pretreated wastewater;

[0075] There is no requirement for the shapes of the first filter screen and the second filter screen, and the mesh openings of the first filter screen are larger than the mesh openings of the second filter screen.

[0076] Specifically, by filtering and standing the desulfurized wastewater, solid impurities and precipitates in the desulfurized wastewater are removed, the impact of reactions in subsequent reactions is reduced, and the accuracy of subsequent reactions is improved. By adjusting the angle of the laminated cathode plate in the electrocatalytic Fenton cell from any angle to the first optimal angle, the rate of hydrogen peroxide produced by the laminated cathode plate in the electrocatalytic Fenton cell is maximized, the rate at which ferrous ions produced by the laminated anode plate in the electrocatalytic Fenton cell react with the hydrogen peroxide is increased, the efficiency of hydroxyl radicals produced by the ferrous ions and the hydrogen peroxide is increased, the mineralization efficiency of organic matter in the pretreated wastewater is increased, and the COD removal rate is greatly improved. By reacting the pretreated wastewater in the electrocatalytic Fenton cell for a second time period, The organic matter in the pretreated wastewater must be fully mineralized, and the angle of the stacked membrane anode plate in the electrochemical oxidation tank is adjusted from any angle to the second optimal angle, so that the rate of ferrous ions generated in the electrochemical oxidation tank is maximized, the complex generated in the electrocatalytic Fenton cell is mineralized, and the ferrous ions are released, which greatly improves the recycling of ferrous ions and the removal rate of COD. The fifth treated wastewater is obtained after the reaction process of the first calculated value, so that it is predicted whether the treated wastewater meets the emission standard, which saves process time and improves process efficiency. The fifth treated wastewater is injected into the first treatment tank through the electrodialysis membrane for chloride ion detection, so that the fifth treated wastewater is subjected to chloride ion removal, the standard of zero emission of desulfurization wastewater is achieved, and the recycling of desulfurization wastewater is realized.

[0077] Specifically, the first optimal angle obtained according to the preset first test cycle includes:

[0078] Setting a first initial angle of the stacked film cathode plate in the electrocatalytic Fenton cell, dividing the angle of the stacked film cathode plate from the first initial angle to the first limit angle of the stacked film cathode plate, and obtaining a plurality of first angles, wherein the stacked film cathode plate rotates from the first initial angle to the first limit angle of the stacked film cathode plate as the first test cycle;

[0079] Detecting the hydrogen peroxide rates generated at the first angles in the same time period to obtain a plurality of first detection data;

[0080] A plurality of the first detection data are sorted and output as a first sequence, the data sorted first in the first sequence is used as a first hydrogen peroxide rate, and the angle corresponding to the first hydrogen peroxide rate is used as a first optimal angle.

[0081] Specifically, the first initial angle to the first limit angle include all angles at which the laminated film cathode plate can rotate, and the laminated film cathode plate is rotated from the first initial angle to the first limit angle of the laminated film cathode plate. The angles are divided according to the same interval angle between adjacent angles, and no specific value of the interval angle is required; the rate of the hydrogen peroxide can be determined by using a fluorescence spectrometer to monitor the change in the optical signal when the laminated film cathode plate produces hydrogen peroxide, and the generation rate of the hydrogen peroxide can be inferred by the change in the intensity of the optical signal.

[0082] Specifically, by setting the first initial angle of the stacked film cathode plate in the electrocatalytic Fenton cell, the measurement target is clear at the beginning of the measurement, and by dividing the angle of the stacked film cathode plate from the first initial angle to the first limit angle of the stacked film cathode plate, the measurement is simple and clear, and the detection efficiency is improved. By detecting the hydrogen peroxide rates generated by several first angles in the same time period, several first detection data results obtained from the hydrogen peroxide rate detection at different angles are accurate. By sorting several first detection data, the values ​​of the first detection data are clear, and it is convenient to extract the maximum value, which improves the efficiency of obtaining the first optimal angle.

[0083] See also Figure 2 As shown, obtaining the first treated wastewater includes:

[0084] Step S21, injecting the pretreated wastewater into the electrocatalytic Fenton cell, and detecting the COD content in the pretreated wastewater as a first COD content;

[0085] Step S22, turning on the power supply of the electrocatalytic Fenton cell, adjusting the angle of the laminated film cathode plate in the electrocatalytic Fenton cell from any angle to the first optimal angle, performing real-time detection on the hydrogen peroxide content generated by the laminated film cathode plate in the electrocatalytic Fenton cell, and obtaining a plurality of detection data as a plurality of first hydrogen peroxide data;

[0086] Step S23, performing real-time detection on the ferrous ion content generated on the stacked membrane anode plate in the electrocatalytic Fenton cell, and obtaining a plurality of detection data as a plurality of first ferrous ion data;

[0087] Step S24, performing ratio calculation on a number of the first ferrous ion data and a number of the first hydrogen peroxide data to obtain a number of first ratios. When the first ratios are the same as the first standard ratios, turning off the power supply of the electrocatalytic Fenton cell, and obtaining the first treated wastewater after a first period of reaction.

[0088] Specifically, the COD content can be detected by using a chemical reagent, such as dimethyl nitrite, to oxidize the organic matter in the wastewater sample to form a colored compound, and then using a spectrophotometer to measure the absorbance of the compound, and calculating the COD content based on the absorbance value.

[0089] Specifically, by injecting the second treated wastewater into the electrocatalytic Fenton cell and turning on the power supply of the electrocatalytic Fenton cell, the complex produced in the electrocatalytic Fenton cell is mineralized and the ferrous ions are released, thereby greatly improving the recycling of ferrous ions and the COD removal rate. By adjusting the angle of the stacked membrane anode plate in the electrochemical oxidation cell from any angle to the second optimal angle, the efficiency of the ferrous ions produced in the electrochemical oxidation cell is the highest. Through the reaction in the second time period, the complex produced in the electrocatalytic Fenton cell is completely mineralized and the ferrous ions are completely released. By detecting the second COD content, the COD content in the second treated wastewater after the reaction between the electrocatalytic Fenton cell and the electrochemical oxidation cell is recorded, providing a calculation data basis for the subsequent calculation of the number of treatment processes that the wastewater needs to undergo.

[0090] Specifically, the second optimal angle obtained according to the preset second test cycle includes:

[0091] Setting a second initial angle of the laminated film anode plate in the electrochemical oxidation cell, dividing the angle of the laminated film anode plate from the second initial angle to the second limit angle of the laminated film anode plate, and obtaining a plurality of second angles, wherein the first test cycle is the angle from the second initial angle to the second limit angle of the laminated film anode plate;

[0092] Detecting the ferrous ion rates generated at the plurality of second angles in the same time period to obtain a plurality of second detection data;

[0093] A plurality of the second detection data are sorted and output as a second sequence, the first-ranked data in the second sequence is used as the first ferrous ion rate, and the angle corresponding to the first ferrous ion rate is used as the second optimal angle.

[0094] Specifically, the second initial angle to the second extreme angle include all angles at which the laminated film anode plate can rotate, and the laminated film anode plate is rotated from the second initial angle to the second extreme angle of the laminated film anode plate. The angles are divided according to the same interval angle between adjacent angles, and no specific values ​​of the interval angles are required.

[0095] Specifically, by setting the second initial angle of the laminated film anode plate in the electrochemical oxidation cell, the initial target is clear during the measurement process, which is convenient for subsequent measurements. By rotating the laminated film anode plate from the second initial angle to the second extreme angle of the laminated film anode plate and performing angle division, the measurement result is comprehensive, the measurement process is simple and clear, and the detection rate is improved. By detecting the ferrous ion rates generated by several second angles in the same time period, the ferrous ion rate data measured at different angles are accurate. By sorting several second detection data, the second detection data are clear, which saves the time for extracting the maximum value in the second detection data and improves the efficiency of obtaining the second optimal angle.

[0096] See also Figure 3 As shown, when the second ferrous ion data in the first treated wastewater is the same as the second standard ferrous ion data, obtaining the second treated wastewater includes:

[0097] Step S31, injecting the first treated wastewater into the electrochemical oxidation tank, and turning on the power supply of the electrochemical oxidation tank;

[0098] Step S32, adjusting the angle of the laminated anode plate in the electrochemical oxidation cell from any angle to the second optimal angle, detecting the content of ferrous ions generated in the electrochemical oxidation in real time, and obtaining a plurality of detection data as a plurality of second ferrous ion data;

[0099] Step S33, when the plurality of the second ferrous ion data are equal to the second standard ferrous ion data, turning off the power supply of the electrochemical oxidation tank, and obtaining the second treated wastewater after a reaction in a second time period;

[0100] Step S34, detecting the COD content of the second treated wastewater as a second COD content.

[0101] Specifically, the ferrous ion content can be determined by measuring the current or potential change of the laminated anode plate.

[0102] Specifically, by injecting the second treated wastewater into the electrochemical oxidation tank and turning on the power of the electrochemical oxidation tank, the complex produced in the electrocatalytic Fenton tank is mineralized and the ferrous ions are released, thereby greatly improving the recycling of ferrous ions and the COD removal rate. By adjusting the angle of the stacked membrane anode plate in the electrochemical oxidation tank from any angle to the second optimal angle, the efficiency of the ferrous ions produced in the electrochemical oxidation tank is the highest. Through the reaction in the second time period, the complex produced in the electrocatalytic Fenton tank is completely mineralized and the ferrous ions are completely released. By detecting the second COD content, the COD content in the second treated wastewater after the reaction between the electrocatalytic Fenton tank and the electrochemical oxidation tank is recorded, providing a calculation data basis for the subsequent calculation of the number of treatment processes that the wastewater needs to undergo.

[0103] Specifically, injecting the second treated wastewater into the electrocatalytic Fenton cell to obtain the third treated wastewater comprises:

[0104] injecting the second treated wastewater into the electrocatalytic Fenton cell, and turning on the power supply of the electrocatalytic Fenton cell;

[0105] detecting a rate of hydrogen peroxide generated by the laminated film cathode plate in the electrocatalytic Fenton cell as a second hydrogen peroxide rate, and when the second hydrogen peroxide rate is greater than or equal to the first hydrogen peroxide rate, not adjusting the angle of the laminated film cathode plate in the electrocatalytic Fenton cell; and when the second hydrogen peroxide rate is less than the first hydrogen peroxide rate, adjusting the angle of the laminated film cathode plate in the electrocatalytic Fenton cell within a first angle range, detecting the hydrogen peroxide rate within the first angle range, acquiring a plurality of third detection data, taking the angle of the laminated film cathode plate corresponding to the maximum value among the plurality of third detection data as a third optimal angle, and adjusting the laminated film cathode plate from the first optimal angle to the third optimal angle;

[0106] The hydrogen peroxide content generated by the stacked membrane cathode plate in the electrocatalytic Fenton cell is monitored in real time, and a plurality of detection data are obtained as a plurality of second hydrogen peroxide data; the ferrous ion content generated by the stacked membrane anode plate in the electrocatalytic Fenton cell is detected in real time, and a plurality of detection data are obtained as a plurality of third ferrous ion data;

[0107] A ratio calculation is performed on a number of the third ferrous ion data and a number of the second hydrogen peroxide data to obtain a number of second ratios. When the second ratio is the same as the second standard ratio, the power supply of the electrocatalytic Fenton cell is turned off, and the third treated wastewater is obtained after a reaction in a first time period.

[0108] Specifically, by detecting the rate of hydrogen peroxide produced by the stacked membrane cathode plate in the electrocatalytic Fenton cell, it is determined whether to adjust the first optimal angle so that the rate of hydrogen peroxide produced in the electrocatalytic Fenton cell is maximized during the process of obtaining the third treated wastewater, thereby increasing the rate of the reaction process with ferrous ions, thereby improving the efficiency of mineralization of organic matter in the wastewater and accelerating the removal efficiency of COD in the wastewater.

[0109] Specifically, injecting the third treated wastewater into an electrochemical oxidation tank for reaction to obtain fourth treated wastewater comprises:

[0110] injecting the third treated wastewater into the electrochemical oxidation tank, and turning on the power supply of the electrochemical oxidation tank;

[0111] Detecting the rate of ferrous ions generated by the laminated film anode plate in the electrochemical oxidation cell as a second ferrous ion rate, when the second ferrous ion rate is greater than or equal to the first ferrous ion rate, not adjusting the angle of the laminated film anode plate in the electrochemical oxidation cell, and when the second ferrous ion rate is less than the first ferrous ion rate, adjusting the angle of the laminated film anode plate in the electrochemical oxidation cell within a second angle range, detecting the ferrous ion rate within the second angle range, acquiring a plurality of fourth detection data, taking the angle of the laminated film anode plate corresponding to the maximum value among the plurality of the fourth detection data as a fourth optimal angle, and adjusting the laminated film anode plate from the second optimal angle to the third optimal angle;

[0112] Real-time detection of the ferrous ion content generated in the electrochemical oxidation tank, and acquisition of a number of detection data as a number of fourth ferrous ion data;

[0113] When some of the fourth ferrous ion data are equal to the third standard ferrous ion data, turning off the power supply of the electrochemical oxidation tank, and obtaining the fourth treated wastewater after a reaction in a second time period;

[0114] The COD content of the fourth treated wastewater is detected as the third COD content.

[0115] Specifically, by detecting the rate of ferrous ions generated by the stacked membrane anode plate in the electrochemical oxidation cell, it is determined whether to adjust the second optimal angle so that the rate of obtaining ferrous ions in the electrochemical oxidation cell is the fastest, thereby improving the COD removal efficiency in the wastewater. Through the reaction in the second time period, the complex produced in the electrocatalytic Fenton cell is completely mineralized and the ferrous ions are completely released. By detecting the third COD content, the COD content in the fourth treated wastewater after two reactions in the electrocatalytic Fenton cell and the electrochemical oxidation cell is recorded, providing a calculation data basis for the subsequent calculation of the number of treatment processes that the wastewater needs to undergo.

[0116] Specifically, after the fourth treated wastewater undergoes a reaction process of the first calculated value, obtaining the fifth treated wastewater comprises:

[0117] Calculate the number of reaction processes through the electrocatalytic Fenton cell and the electrochemical oxidation cell by using the first COD content, the second COD content, the third COD content and the standard COD content, and use the calculation result as a first calculated value;

[0118] The COD content in the wastewater obtained after the reaction of the electrocatalytic Fenton cell and the electrochemical oxidation cell of the first calculated value is detected as the fourth COD content. If the fourth COD content is less than or equal to the emission standard COD content, the fifth treated wastewater is the wastewater. If the fourth COD content is greater than the emission standard COD content, the wastewater is subjected to the reaction of the electrocatalytic Fenton cell and the electrochemical oxidation cell again, and the fifth treated wastewater is the wastewater after the reaction.

[0119] Specifically, the number of reaction processes through the electrocatalytic Fenton cell and the electrochemical oxidation cell is calculated by the first COD content, the second COD content, the third COD content and the standard COD content, so that it is predicted whether the treated wastewater meets the discharge standard, which saves process time and improves process efficiency. By detecting the fourth COD content, it is determined whether the wastewater meets the discharge standard. If not, the above process is performed again to complete the mineralization of organic matter in the wastewater, meet the discharge standard, and protect environmental resources.

[0120] See also Figure 4 As shown, electrolysis treatment of the fifth treated wastewater includes:

[0121] Step S51, injecting the fifth treated wastewater into the second treatment tank;

[0122] Step S52, turning on the power of the second treatment tank, collecting the chlorine gas generated by the anode of the second treatment tank through the first collecting device, and discharging the sodium hypochlorite generated by the cathode of the second treatment tank to the second collecting device through the pipeline.

[0123] Specifically, the chlorine gas is collected by an upward exhaust method. The first collecting device includes a ventilation duct and a gas collecting bin. When a moist blue litmus paper is placed at the mouth of the gas collecting bottle and the paper turns red, the gas collecting bin is full and is replaced in time.

[0124] Specifically, the chlorine gas generated by the anode of the second treatment tank is collected by the first collecting device and the sodium hypochlorite generated by the cathode of the second treatment tank is discharged to the second collecting device through a pipeline, so that the desulfurization wastewater can be reused, which saves waste of resources and solves the problem of continuous corrosion of equipment caused by high concentration of chloride ions.

[0125] Specifically, after the fifth treated wastewater is electrolytically treated, the sodium hypochlorite solution arranged in the second collecting device is discharged into the electrocatalytic Fenton cell and the electrochemical oxidation cell to achieve disinfection of the electrocatalytic Fenton cell and the electrochemical oxidation cell.

[0126] Specifically, by discharging the sodium hypochlorite solution arranged in the second collecting device into the electrocatalytic Fenton cell and the electrochemical oxidation cell, the electrocatalytic Fenton cell and the electrochemical oxidation cell are disinfected, thereby realizing the recovery and comprehensive utilization of desulfurization wastewater.

[0127] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

[0128] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for zero-discharge treatment of desulfurization wastewater, characterized in that: include: Step S1, filtering and standing the desulfurization wastewater to obtain pretreated wastewater; Step S2, injecting the pretreated wastewater into the electrocatalytic Fenton cell, adjusting the angle of the stacked membrane cathode plate in the electrocatalytic Fenton cell from any angle to the first optimal angle according to the first optimal angle obtained in the pre-set first test cycle, so that the rate of hydrogen peroxide generated in the electrocatalytic Fenton cell is maximized, and obtaining the first treated wastewater after the pretreated wastewater reacts in the electrocatalytic Fenton cell for a second period of time; The first optimal angle obtained according to the preset first test cycle includes: Setting a first initial angle of the stacked film cathode plate in the electrocatalytic Fenton cell, dividing the angle of the stacked film cathode plate from the first initial angle to the first limit angle of the stacked film cathode plate, and obtaining a plurality of first angles, wherein the stacked film cathode plate rotates from the first initial angle to the first limit angle of the stacked film cathode plate as the first test cycle; Detecting the hydrogen peroxide rates generated at the first angles in the same time period to obtain a plurality of first detection data; sorting the plurality of the first detection data and outputting them into a first sequence, taking the first-ranked data in the first sequence as a first hydrogen peroxide rate, and taking the angle corresponding to the first hydrogen peroxide rate as a first optimal angle; The first initial angle to the first limit angle include all angles at which the laminated film cathode plate can rotate. The laminated film cathode plate is rotated from the first initial angle to the first limit angle of the laminated film cathode plate. The angles are divided according to the same interval angle between adjacent angles. No specific value of the interval angle is required. Obtaining the first treated wastewater includes: Injecting the pretreated wastewater into the electrocatalytic Fenton cell, and detecting the COD content in the pretreated wastewater as a first COD content; Turning on the power supply of the electrocatalytic Fenton cell, adjusting the angle of the laminated film cathode plate in the electrocatalytic Fenton cell from any angle to the first optimal angle, performing real-time detection on the hydrogen peroxide content generated by the laminated film cathode plate in the electrocatalytic Fenton cell, and obtaining a plurality of detection data as a plurality of first hydrogen peroxide data; Performing real-time detection on the ferrous ion content generated on the stacked membrane anode plate in the electrocatalytic Fenton cell, and obtaining a plurality of detection data as a plurality of first ferrous ion data; performing ratio calculation on a plurality of the first ferrous ion data and a plurality of the first hydrogen peroxide data to obtain a plurality of first ratios, and when the first ratios are the same as the first standard ratios, turning off the power supply of the electrocatalytic Fenton cell, and obtaining the first treated wastewater after a reaction in a first time period; Step S3, injecting the first treated wastewater into the electrochemical oxidation tank, adjusting the angle of the laminated anode plate in the electrochemical oxidation tank from any angle to the second optimal angle according to the second optimal angle obtained in the preset second test cycle, so as to maximize the rate of ferrous ions generated in the electrochemical oxidation tank, and obtaining second treated wastewater when the second ferrous ion data in the first treated wastewater is the same as the second standard ferrous ion data; Step S4, injecting the second treated wastewater into the electrocatalytic Fenton cell to obtain third treated wastewater, injecting the third treated wastewater into an electrochemical oxidation cell for reaction to obtain fourth treated wastewater, calculating the number of reaction processes of the electrocatalytic Fenton cell and the electrochemical oxidation cell according to the COD content in the wastewater, taking the calculated result as the first calculated value, and obtaining fifth treated wastewater after the fourth treated wastewater undergoes the reaction process of the first calculated value; Injecting the second treated wastewater into the electrocatalytic Fenton cell to obtain third treated wastewater comprises: injecting the second treated wastewater into the electrocatalytic Fenton cell, and turning on the power supply of the electrocatalytic Fenton cell; detecting a rate of hydrogen peroxide generated by the laminated film cathode plate in the electrocatalytic Fenton cell as a second hydrogen peroxide rate, and when the second hydrogen peroxide rate is greater than or equal to the first hydrogen peroxide rate, not adjusting the angle of the laminated film cathode plate in the electrocatalytic Fenton cell; and when the second hydrogen peroxide rate is less than the first hydrogen peroxide rate, adjusting the angle of the laminated film cathode plate in the electrocatalytic Fenton cell within a first angle range, detecting the hydrogen peroxide rate within the first angle range, acquiring a plurality of third detection data, taking the angle of the laminated film cathode plate corresponding to the maximum value among the plurality of third detection data as a third optimal angle, and adjusting the laminated film cathode plate from the first optimal angle to the third optimal angle; The hydrogen peroxide content generated by the stacked membrane cathode plate in the electrocatalytic Fenton cell is monitored in real time, and a plurality of detection data are obtained as a plurality of second hydrogen peroxide data; the ferrous ion content generated by the stacked membrane anode plate in the electrocatalytic Fenton cell is detected in real time, and a plurality of detection data are obtained as a plurality of third ferrous ion data; Calculating the ratio of the third ferrous ion data and the second hydrogen peroxide data to obtain a plurality of second ratios, and when the second ratios are the same as the second standard ratios, turning off the power supply of the electrocatalytic Fenton cell, and obtaining the third treated wastewater after a reaction in a first time period; Step S5, injecting the fifth treated wastewater into the first treatment tank through the electrodialysis membrane for chloride ion detection, if the chloride ion concentration is less than the chloride ion emission standard concentration, the fifth treated wastewater is recycled as the final treated wastewater, if the chloride ion concentration is greater than or equal to the chloride ion emission standard concentration, the fifth treated wastewater is electrolyzed; The electrolytic treatment of the fifth treated wastewater comprises: injecting the fifth treated wastewater into a second treatment tank; Turning on the power supply of the second treatment tank, collecting the chlorine gas generated by the anode of the second treatment tank through the first collecting device, and discharging the solution generated by the second treatment tank into the second collecting device through the pipeline; It also includes, after electrolytically treating the fifth treated wastewater, discharging the solution disposed in the second collecting device into the electrocatalytic Fenton cell and the electrochemical oxidation cell to achieve disinfection of the electrocatalytic Fenton cell and the electrochemical oxidation cell.

2. The method for zero-discharge treatment of desulfurization wastewater according to claim 1, characterized in that: The second optimal angle obtained according to the preset second test cycle includes: Setting a second initial angle of the laminated film anode plate in the electrochemical oxidation cell, dividing the angle of the laminated film anode plate from the second initial angle to the second limit angle of the laminated film anode plate, and obtaining a plurality of second angles, wherein the first test cycle is the angle from the second initial angle to the second limit angle of the laminated film anode plate; Detecting the ferrous ion rates generated at the plurality of second angles in the same time period to obtain a plurality of second detection data; A number of the second detection data are sorted and output as a second sequence, the first-ranked data in the second sequence is used as the first ferrous ion rate, and the angle corresponding to the first ferrous ion rate is used as the second optimal angle.

3. The zero-discharge treatment method for desulfurization wastewater according to claim 2, characterized in that: When the second ferrous ion data in the first treated wastewater is the same as the second standard ferrous ion data, obtaining the second treated wastewater comprises: injecting the first treated wastewater into the electrochemical oxidation tank, and turning on the power supply of the electrochemical oxidation tank; The angle of the laminated anode plate in the electrochemical oxidation tank is adjusted from any angle to the second optimal angle, the content of ferrous ions generated in the electrochemical oxidation is detected in real time, and a plurality of detection data are obtained as a plurality of second ferrous ion data; When the second ferrous ion data are equal to the second standard ferrous ion data, the power supply of the electrochemical oxidation tank is turned off, and the second treated wastewater is obtained after a reaction in a second time period; The COD content of the second treated wastewater is detected as a second COD content.

4. The method for zero-discharge treatment of desulfurization wastewater according to claim 3, characterized in that: Injecting the third treated wastewater into an electrochemical oxidation tank for reaction to obtain fourth treated wastewater comprises: injecting the third treated wastewater into the electrochemical oxidation tank, and turning on the power supply of the electrochemical oxidation tank; Detecting the rate of ferrous ions generated by the laminated film anode plate in the electrochemical oxidation cell as a second ferrous ion rate, when the second ferrous ion rate is greater than or equal to the first ferrous ion rate, not adjusting the angle of the laminated film anode plate in the electrochemical oxidation cell, and when the second ferrous ion rate is less than the first ferrous ion rate, adjusting the angle of the laminated film anode plate in the electrochemical oxidation cell within a second angle range, detecting the ferrous ion rate within the second angle range, acquiring a plurality of fourth detection data, taking the angle of the laminated film anode plate corresponding to the maximum value among the plurality of the fourth detection data as a fourth optimal angle, and adjusting the laminated film anode plate from the second optimal angle to the fourth optimal angle; Real-time detection of the ferrous ion content generated in the electrochemical oxidation tank, and acquisition of a number of detection data as a number of fourth ferrous ion data; When some of the fourth ferrous ion data are equal to the third standard ferrous ion data, turning off the power supply of the electrochemical oxidation tank, and obtaining the fourth treated wastewater after a reaction in a second time period; The COD content of the fourth treated wastewater is detected as the third COD content.

5. The zero-discharge treatment method for desulfurization wastewater according to claim 4, characterized in that: After the fourth treated wastewater undergoes a reaction process of the first calculated value, obtaining the fifth treated wastewater comprises: Calculate the number of reaction processes through the electrocatalytic Fenton cell and the electrochemical oxidation cell by using the first COD content, the second COD content, the third COD content and the standard COD content, and use the calculation result as a first calculated value; The COD content in the wastewater obtained after the reaction of the electrocatalytic Fenton cell and the electrochemical oxidation cell according to the first calculated value is detected as the fourth COD content. If the fourth COD content is less than or equal to the emission standard COD content, a first reaction result is obtained after the reaction of the electrocatalytic Fenton cell and the electrochemical oxidation cell for the first calculated value times, and the first reaction result is the fifth treated wastewater. If the fourth COD content is greater than the emission standard COD content, after the reaction of the electrocatalytic Fenton cell and the electrochemical oxidation cell according to the first calculated value, a second reaction result is obtained after the reaction of the electrocatalytic Fenton cell and the electrochemical oxidation cell is performed again, and the second reaction result is the fifth treated wastewater.

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