A method and device for purifying phosphorus-sulfur-containing malodorous gas

Abstract

The present invention discloses a method and device for purifying phosphorus-sulfur-containing malodorous gas. The reaction device is provided with two-stage absorption tanks. A 0.02-0.18 mol / L chlorine-containing solution is added to the first-stage absorption tank, and a constant direct current is passed to generate a strong oxidizing chlorine-containing active component in the absorption liquid. The malodorous gas containing phosphine and hydrogen sulfide is oxidized in the first-stage absorption tank and then sent to the second-stage absorption tank for alkaline solution absorption treatment. When the phosphine content in the outlet tail gas is detected to be higher than 0.3 mg / m 3 When the absorption liquid in the first stage absorption tank is discarded, 15-40% of the absorption liquid in the second stage absorption tank is taken to replenish the absorption liquid in the first stage absorption tank, and hydrochloric acid and chlorine-containing solution are added to the original state of the absorption tank. Similarly, the second stage absorption tank is replenished with an equal volume of the original absorption alkali solution. The technical method of the present invention is simple to operate and has low operating costs. It is suitable for the purification of phosphorus and sulfur tail gas such as landfill, sewage treatment, yellow phosphorus or acetylene production, and has a high efficiency purification effect on phosphine and hydrogen sulfide odor gases in different concentration ranges.

Description

Technical Field

[0001] The invention relates to a method and a device for purifying phosphorus-sulfur-containing malodorous gas, belonging to the technical field of air pollution control engineering and pollution prevention. Background Art

[0002] Malodorous gases come from a wide range of sources and can cause varying degrees of toxicity to the human respiratory, cardiovascular, endocrine, and nervous systems. As typical malodorous gases, phosphine and hydrogen sulfide are widely derived from landfills, sewage treatment, and industrial production processes such as semiconductors, yellow phosphorus, and acetylene. On the one hand, phosphorus-sulfur-containing malodorous gases pose a serious threat to human health. For example, if the concentration of phosphine reaches 50 mg / m 3 When exposed to phosphine, it will cause death in just 30 minutes; hydrogen sulfide has a significant irritating effect on the human respiratory tract. As its concentration increases, it will also harm the central nervous system and even cause suffocation and death of humans and animals. On the other hand, phosphine and hydrogen sulfide are also typical catalyst poisons, affecting the subsequent purification and resource utilization of industrial gases.

[0003] At present, the purification technology of phosphorus-sulfur malodorous gas can be roughly divided into two categories: dry method and wet method. Dry technology mainly uses solid materials to adsorb phosphorus and sulfur components and separate them from the gas phase. Wet technology uses liquid absorbents to purify the mixed gas. After a series of physical and chemical reactions, the phosphorus and sulfur components are transferred from the gas phase to the liquid phase or precipitated solid substances are generated. Both phosphine and hydrogen sulfide in malodorous gas are reducing and can react with strong oxidants (such as potassium permanganate, hydrogen peroxide, etc.) to be removed from the gas phase. However, it is often difficult to regenerate catalysts or adsorbents, and most strong oxidants are highly corrosive, which makes the efficient purification of phosphorus-sulfur malodorous gas face a series of problems such as high technical difficulty, high treatment cost, and complex operation.

[0004] Existing patent ZL201310526458.6 uses electrochemical and liquid-phase catalytic oxidation synergistic technology to treat mixed gases containing one or more components of phosphorus, sulfur, and cyanide. This technology requires the use of precious metal palladium as a catalyst, and the amount added is relatively large, which significantly increases the cost of purifying harmful gases. Patent CN201611218299.3 discloses an electrochemical method for treating phosphine gas. The phosphine tail gas is pressed into a gas compression chamber through a pressurized gas pump and passes through a gas diffusion anode. It is oxidized into phosphate at the anode / electrolyte interface, and the remaining phosphine dissolves in the electrolyte and is further oxidized, thereby achieving complete absorption and degradation of phosphine. This method has complex process equipment and requires pressurization during the treatment process, which greatly reduces the service life of the equipment. Patent CN201910021453.5 compresses multi-walled carbon nanotubes, screens, pre-treats, and ultrasonically impregnates them before drying and activating them. Low-temperature plasma modification and activation are used to obtain a catalyst that has a good simultaneous removal effect on phosphine, hydrogen sulfide, and hydrogen cyanide. However, the developed technical method and catalyst preparation method are complex, and catalyst regeneration is often very difficult. It can be seen that the development of phosphorus and sulfur odor gas purification technology with a relatively simple process and lower operating costs is of great significance to protecting human health or the resource utilization of industrial tail gas. Summary of the invention

[0005] The present invention provides a technical method for purifying phosphorus-sulfur-containing malodorous gases by electrochemical means, wherein a chlorine-containing solution is added to the first-stage absorption tank, an alkaline solution corresponding to the metal cation is added to the second-stage absorption tank, and an electrode group is arranged in the first-stage absorption tank to construct an electrochemical system. After a constant direct current is introduced, the phosphine and hydrogen sulfide malodorous gases are blown into the absorption liquid from the microporous aeration device located at the center of the first-stage absorption tank, and the active chlorine-containing components generated by electrolysis are converted into corresponding phosphorus and sulfur oxides after forced oxidation and transferred into the absorption liquid; the alkaline solution in the second-stage absorption tank reabsorbs the gas emitted during the purification process of the first-stage absorption tank; when the phosphine concentration in the outlet tail gas is higher than 0.3 mg / m 3 When the solution in the first stage absorption tank is partially discarded, then the same volume of absorption liquid in the second stage absorption tank is taken to replenish the first stage absorption tank, and the pH value and chloride ion content are adjusted; the second stage absorption tank is replenished with the same volume of original absorption alkali solution. In this way, phosphorus and sulfur odorous gases are continuously purified.

[0006] The implementation steps of the present invention are as follows:

[0007] (1) Prepare sodium chloride or potassium chloride into an absorption solution, adjust its pH value and add it to the absorption tank of stage I. Prepare sodium hydroxide or potassium hydroxide solution accordingly and add it to the absorption tank of stage II.

[0008] (2) The first stage absorption tank is designed as a cylindrical reactor. The electrode group anode is installed in the center of the absorption tank. The anode is made of mesh titanium material into a ring shape. The inner wall of the mesh anode is tightly fitted with the microporous aeration device. The titanium material plate is loaded with ruthenium-iridium metal components; the cathode plate of the electrode group is tightly attached to the inner wall of the absorption tank; the phosphorus and sulfur odorous gases to be treated are blown into the absorption liquid from the microporous aeration device located in the center of the first stage absorption tank for purification.

[0009] (3) The outlet gas of the first stage absorption tank is sent to the second stage absorption tank for secondary purification. When the concentration of phosphine in the outlet gas of the second stage absorption tank is detected to be higher than 0.3 mg / m 3 At the same time, part of the absorption liquid in the absorption tank of stage I is discarded, and an equal volume of the absorption liquid in the absorption tank of stage II is transferred to the absorption tank of stage I, its pH value is adjusted with hydrochloric acid and chlorine-containing electrolyte is added to maintain the appropriate chloride ion content in the absorption tank of stage I; an equal volume of the original absorption alkali solution is added to the absorption tank of stage II.

[0010] Preferably, in step (1), the electrolyte is sodium chloride, and the chloride ion concentration is 0.05-0.15 mol / L.

[0011] Preferably, in step (1), the pH value of the electrolyte solution is adjusted to 6.5-7.0 using hydrochloric acid.

[0012] Preferably, in step (2), the cathode is made of a pure titanium sheet, and the anode is made of a mesh titanium material loaded with ruthenium-iridium metal components into a ring shape and installed in the center of the absorption tank, and the inner wall of the mesh anode is tightly fitted with the microporous aeration device.

[0013] Preferably, the anode current density in the absorption tank of step (2) section I is 80-120 mA / cm 2 .

[0014] Preferably, the oxygen content in the phosphorus and sulfur odorous gas to be treated in step (2) is 0.8-1.5%.

[0015] Preferably, the concentration of phosphine in the tail gas at the outlet of the absorber in stage II of step (3) is higher than 0.3 mg / m 3 When the absorption liquid in the absorption tank of stage I is discarded, 25-40% of the absorption liquid in the absorption tank of stage II is taken and added to the absorption tank of stage I.

[0016] The working principle and working process of the device of the present invention: two-stage absorption is used to purify the phosphorus-sulfur-containing malodorous gas. The gas to be treated is transported from the air guide pipe 4 to the first-stage absorption tank 1 through the flow meter 3. The gas enters the chlorine-containing absorption liquid through the microporous aeration device 5. After the chlorine-containing active components produced by the electrolysis of the constant current power supply 6 are forcibly oxidized, they enter the second-stage absorption tank 2 through the gas outlet 9 of the first-stage absorption tank. Alkaline absorption liquid is blown into the aeration device 5 to complete the secondary absorption. The purified gas is discharged through the outlet tail gas discharge port 10. When the phosphine concentration in the outlet gas is higher than 0.3mg / m3 At the same time, part of the absorption liquid is discharged from the discharge port 11 of the stage I absorption tank and discarded, and then an equal volume of absorption liquid is discharged from the discharge port 11 of the stage II absorption tank and added to the stage I absorption tank from the liquid inlet 12, and the pH value and the chloride ion content are adjusted to the initial levels with hydrochloric acid and a chlorine-containing reagent, and at the same time, an equal volume of alkali solution is added to the stage II absorption tank from the liquid inlet 12.

[0017] Technical effects of the present invention:

[0018] (1) Sodium chloride and potassium chloride are used as absorption liquids to purify phosphorus and sulfur-containing odorous gases through electrochemical methods. The raw materials are widely available and inexpensive, with fast absorption rates and good purification effects. The hydrogen sulfide purification efficiency is stably maintained at above 99.7%.

[0019] (2) After the absorption treatment in stage I, the volatilized small amount of chlorine-containing tail gas is subjected to absorption treatment in stage II to fully ensure the absorption effect. During the absorption process, the chlorine content of the absorption liquid in the absorption tank in stage I does not decrease significantly, and the purification of phosphorus and sulfur odorous gases can operate stably for a long time. When the concentration of electrolyte sodium chloride in the absorption tank in stage I is 0.12 mol / L, even if the concentration of phosphine in the intake air is as high as 150 mg / m 3 The absorption system of the present invention can maintain a phosphine removal efficiency of more than 99.8% within 90 hours. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 -Purification device for malodorous gases containing phosphorus and sulfur;

[0021] In the figure: 1. Section I absorption tank, 2. Section II absorption tank, 3. Flow meter, 4. Air guide pipe, 5. Microporous aeration device, 6. Constant current power supply, 7. Microporous annular anode, 8. Pure titanium thin plate cathode, 9. Section I absorption tank gas outlet, 10. Exhaust gas outlet, 11. Absorption tank liquid outlet, 12. Absorption tank liquid inlet. DETAILED DESCRIPTION

[0022] The present invention is described in detail below in conjunction with specific embodiments. The embodiments are implemented based on the technical solution of the present invention, and provide detailed implementation methods and specific operating processes, but the protection scope of the present invention is not limited to the contents.

[0023] like Figure 1As shown, the purification device for phosphorus-sulfur-containing malodorous gas of the present invention comprises a stage I absorption tank 1, a stage II absorption tank 2, a flow meter 3, an air guide pipe 4, a microporous aeration device 5, a constant current power supply 6, a microporous annular anode 7, a pure titanium thin plate cathode 8, a stage I absorption tank gas outlet 9, an outlet tail gas discharge port 10, an absorption tank drain port 11, and an absorption tank inlet 12. The upper ends of the stage I absorption tank 1 and the stage II absorption tank 2 are both provided with an absorption tank inlet 12, and the lower ends are both provided with an absorption tank drain port 11, and the center of the absorption tank near the bottom is provided with a microporous aeration device 5. Phosphorus and sulfur-containing malodorous gases are delivered to the microporous aeration device 5 of the stage I absorption tank 1 through an air duct 4, on which a flow meter 3 is also provided. A microporous annular anode 7 and a pure titanium thin plate cathode 8 are provided in the stage I absorption tank 1, the electrode plates of the pure titanium thin plate cathode 8 are in close contact with the inner wall of the absorption tank, the microporous annular anode 7 is made into a circular ring shape and the inner side of the mesh anode is in close contact with the microporous aeration device 5; the gas outlet 9 of the stage I absorption tank is connected to the microporous aeration device 5 of the stage II absorption tank 2 through an air duct, and an outlet exhaust gas discharge port 10 is also provided at the top of the stage II absorption tank 2.

[0024] The method for purifying phosphorus-sulfur-containing malodorous gas of the present invention purifies phosphorus-sulfur-containing malodorous gas by two-stage absorption tanks, wherein a chlorine-containing solution is added as an absorption liquid in the first-stage absorption tank, and a constant direct current is passed to generate a strong oxidizing chlorine-containing component in the absorption liquid to oxidize phosphine and sulfur sulfide malodorous gas components in the intake gas, and the gas at the outlet of the first-stage absorption tank is sent to the second-stage absorption tank with an alkali solution concentration of 0.02 mol / L for absorption treatment; when the phosphine concentration in the tail gas at the outlet of the second-stage absorption tank begins to be higher than 0.3 mg / m 3 At the same time, part of the absorption liquid in the stage I absorption tank is discarded, and an equal volume of the absorption liquid in the stage II absorption tank is taken to supplement the stage I absorption tank, and hydrochloric acid and chlorine-containing solution are added to make the pH value and chlorine content of the mixed solution in the stage I absorption tank the same as the initial values, and the stage II absorption tank is supplemented with an equal volume of the original absorption alkali solution to achieve the purification of phosphorus and sulfur odorous gases in various concentration ranges.

[0025] Preferably, an anode and a cathode electrode group are provided in the stage I absorption tank, the cathode is made of a conductive material with a high hydrogen evolution potential and resistance to chlorine corrosion, and the electrode plate is in close contact with the inner wall of the absorption tank, and the anode is made of a mesh titanium material loaded with ruthenium-iridium metal components into a ring shape and installed in the center of the absorption tank, and the inner side of the mesh anode is in close contact with the microporous aeration device.

[0026] Preferably, the phosphorus-sulfur-containing malodorous gas to be treated is blown into the absorption liquid from a microporous aeration device installed in the center of the absorption tank, and the volume ratio of the inlet gas to the absorption liquid is (1-2): 5 (measured in nuclei per minute).

[0027] Preferably, sodium chloride and / or potassium chloride are used as the absorption liquid in the stage I absorption tank, and the concentration thereof is 0.02-0.18 mol / L.

[0028] Preferably, the anode current density is controlled to be 50-160 mA / cm by a constant current DC power supply. 2 .

[0029] Preferably, the oxygen content in the intake air is controlled to be 0-7.5%.

[0030] Preferably, when the oxygen content in the inlet gas is lower than 0.5%, the initial pH value of the electrolyte solution in the stage I absorption tank is controlled to be 7.0-8.0; when the oxygen content in the inlet gas is 0.5-7.5%, the initial pH value of the electrolyte solution in the stage I absorption tank is controlled to be 6.0-7.0.

[0031] Preferably, the phosphine concentration in the tail gas at the outlet of the stage II absorber starts to be higher than 0.3 mg / m 3 When the absorption liquid in the absorption tank of stage I is discarded, 15-40% of the absorption liquid in stage I is discarded.

[0032] Example 1

[0033] Prepare 0.12mol / L sodium chloride solution, adjust the pH value to 7.2 and add it to the absorption tank in stage I. Determine the amount of absorption liquid according to the height of 4 / 5 of the absorption tank. Prepare 0.02mol / L sodium hydroxide solution and add it to the absorption tank in stage II. Set the concentrations to 500 and 920mg / m 3 The phosphine and hydrogen sulfide mixed gas is introduced into the absorption tank of stage I. The ventilation intensity is determined according to the volume ratio of the mixed gas to the absorption liquid of 2:5 (calculated according to nuclei per minute). An external electric field is applied to the absorption tank of stage I through a constant current power supply, and its anode current density is 150mA / cm 2 .

[0034] After 84 hours of continuous operation, the outlet phosphine concentration began to exceed 0.30 mg / m 3 , the hydrogen sulfide removal rate is still as high as 99.9%; 20% of the absorption liquid in the first stage absorption tank is removed and discarded, and the same amount of absorption liquid in the second stage absorption tank is added to the first stage absorption tank, and the pH value of the absorption liquid is adjusted to 7.2 with hydrochloric acid, and the chloride ion concentration in the absorption liquid is adjusted to 0.12mol / L by adding sodium chloride, and the second stage absorption tank is supplemented with an equal volume of 0.02mol / L sodium hydroxide solution. Phosphine and hydrogen sulfide odor gases are continued to be introduced for purification.

[0035] Example 2

[0036] Prepare 0.18 mol / L sodium chloride solution, adjust the pH value to 7.5 and add it to the absorption tank of stage I. Add 0.02 mol / L sodium hydroxide solution to the absorption tank of stage II. Control the anode current density to 120 mA / cm by constant current power supply. 2 , the tail gas purification equipment and other process parameters are the same as those in Example 1.

[0037] After 92 hours of continuous operation, the outlet phosphine concentration began to exceed 0.30 mg / m 3 , the hydrogen sulfide removal rate was 100%; 15% of the absorption liquid in the first stage absorption tank was removed and discarded, and an equal amount of absorption liquid in the second stage absorption tank was added to the first stage absorption tank, and the pH value of the absorption liquid was adjusted to 7.5 with hydrochloric acid, and the chloride ion concentration in the absorption liquid was adjusted to 0.18 mol / L by adding sodium chloride, and the second stage absorption tank was supplemented with an equal volume of 0.02 mol / L sodium hydroxide solution. Phosphine and hydrogen sulfide odor gases were continued to be introduced for purification.

[0038] Example 3

[0039] Prepare 0.12 mol / L potassium chloride solution, adjust the pH value to 7.0 and add it to the absorption tank of stage I. Add 0.02 mol / L potassium hydroxide solution to the absorption tank of stage II. Determine the ventilation intensity according to the volume ratio of mixed gas to absorption liquid of 1.5:5 (based on nuclei per minute). Control the anode current density to 100 mA / cm by constant current power supply. 2 , the tail gas purification equipment and other process parameters are the same as those in Example 1.

[0040] After 76 hours of continuous operation, the outlet phosphine concentration began to exceed 0.30 mg / m 3 , the hydrogen sulfide removal rate is 99.8%; 30% of the absorption liquid in the first stage absorption tank is removed and discarded, and an equal amount of absorption liquid in the second stage absorption tank is added to the first stage absorption tank, and the pH value of the absorption liquid is adjusted to 7.0 with hydrochloric acid, and potassium chloride is added to adjust the chloride ion concentration in the absorption liquid to 0.12mol / L, and the second stage absorption tank is supplemented with an equal volume of 0.02mol / L potassium hydroxide solution. Phosphine and hydrogen sulfide odor gases are continuously introduced for purification.

[0041] Example 4

[0042] Prepare 0.10 mol / L sodium chloride solution, adjust the pH value to 6.5 and add it to the absorption tank of stage I. Add 0.02 mol / L sodium hydroxide solution to the absorption tank of stage II. Control the anode current density to 90 mA / cm by constant current power supply. 2 The concentrations of phosphine and hydrogen sulfide in the mixed gas to be treated are 80 and 155 mg / m 3 , the oxygen content is 1.0%, and the tail gas purification equipment and other process parameters are the same as those in Example 1.

[0043] After 320 hours of continuous operation, the outlet phosphine concentration began to exceed 0.30 mg / m 3, the hydrogen sulfide removal rate is 100%; 30% of the absorption liquid in the first stage absorption tank is removed and discarded, and the same amount of absorption liquid in the second stage absorption tank is added to the first stage absorption tank, and the pH value of the absorption liquid is adjusted to 6.5 with hydrochloric acid, and sodium chloride is added to adjust the chloride ion concentration in the absorption liquid to 0.10mol / L, and the same volume of 0.02mol / L sodium hydroxide solution is added to the second stage absorption tank. Continue to pass the mixed gas for purification.

[0044] Example 5

[0045] Prepare 0.02 mol / L sodium chloride solution, adjust the pH value to 6.2 and add it to the absorption tank of stage I. Add 0.02 mol / L sodium hydroxide solution to the absorption tank of stage II. Determine the ventilation intensity according to the volume ratio of mixed gas to absorption liquid of 1:5 (calculated per minute). Control the anode current density to 60 mA / cm by constant current power supply. 2 , the tail gas purification equipment and other process parameters are the same as those in Example 4.

[0046] After 70 hours of continuous operation, the outlet phosphine concentration began to exceed 0.30 mg / m 3 , the hydrogen sulfide removal rate is 100%; 40% of the absorption liquid in the first stage absorption tank is removed and discarded, and the same amount of absorption liquid in the second stage absorption tank is added to the first stage absorption tank, and the pH value of the absorption liquid is adjusted to 6.2 with hydrochloric acid, and sodium chloride is added to adjust the chloride ion concentration in the absorption liquid to 0.02mol / L, and the same volume of 0.02mol / L sodium hydroxide solution is added to the second stage absorption tank. Continue to pass the mixed gas for purification.

Claims

1. A method for purifying phosphorus-sulfur-containing malodorous gas, characterized in that The phosphorus and sulfur-containing malodorous gas is purified by two-stage absorption tanks. A chlorine-containing solution is added to the absorption tank of stage I as the absorption liquid, and a constant direct current is passed to produce a strong oxidizing chlorine-containing component in the absorption liquid to oxidize the phosphine and hydrogen sulfide malodorous gas components in the intake air. The gas at the outlet of stage I absorption tank is sent to the stage II absorption tank with an alkaline solution concentration of 0.02 mol / L for absorption treatment; when the phosphine concentration in the tail gas at the outlet of stage II absorption tank begins to exceed 0.3 mg / m 3 When the absorption liquid of the first stage absorption tank is discarded, the absorption liquid of the second stage absorption tank of the same volume as the discarded part of the absorption liquid of the first stage absorption tank is taken to supplement the first stage absorption tank, and hydrochloric acid and chlorine-containing solution are added to make the pH value and chloride ion concentration of the mixed solution in the first stage absorption tank the same as the initial value, and the second stage absorption tank is supplemented with the original absorption alkali solution of the same volume as the discarded part of the absorption liquid of the first stage absorption tank, so as to achieve the purification of phosphorus and sulfur odorous gases in various concentration ranges; sodium chloride and / or potassium chloride are used as the absorption liquid of the first stage absorption tank, and the concentration thereof is 0.02-0.18 mol / L; the alkali solution used in the second stage absorption tank is sodium hydroxide or potassium hydroxide; the outlet gas of the first stage absorption tank is chlorine-containing tail gas; an anode and a cathode electrode group are arranged in the first stage absorption tank, the cathode plate is close to the inner wall of the absorption tank, the anode is made of a mesh titanium material loaded with ruthenium-iridium metal components into a ring shape and installed in the center of the absorption tank, and the inner side of the mesh anode is tightly fitted with the microporous aeration device.

2. The method for purifying phosphorus-sulfur malodorous gas according to claim 1, characterized in that The phosphorus and sulfur-containing odorous gas to be treated is blown into the absorption liquid from the microporous aeration device installed in the center of the absorption tank, and the volume ratio of the inlet gas to the absorption liquid is (1-2):

5.

3. The method for purifying phosphorus-sulfur-containing malodorous gas according to claim 1, characterized in that The anode current density is controlled by a constant current DC power supply to 50-160 mA / cm 2 .

4. The method for purifying phosphorus-sulfur-containing malodorous gas according to claim 1, characterized in that Control the oxygen content in the intake air to 0-7.5%.

5. The method for purifying phosphorus-sulfur-containing malodorous gas according to claim 1, characterized in that When the oxygen content in the intake air is lower than 0.5%, the initial pH value of the electrolyte solution in the stage I absorption tank is controlled to be 7.0-8.

0. When the oxygen content in the intake air is 0.5-7.5%, the initial pH value of the electrolyte solution in the stage I absorption tank is controlled to be 6.0-7.

0.

6. The method for purifying phosphorus-sulfur malodorous gas according to claim 1, characterized in that The concentration of phosphine in the tail gas at the outlet of the absorber in stage II begins to exceed 0.3 mg / m 3 When the absorption liquid in the absorption tank of stage I is discarded, 15-40% of the absorption liquid in stage I is discarded.

7. A purification device used in the method for purifying phosphorus-sulfur malodorous gas according to any one of claims 1 to 6, characterized in that The invention comprises a first-stage absorption tank (1), a second-stage absorption tank (2), a flow meter (3), an air guide pipe (4), a microporous aeration device (5), a constant current power supply (6), a microporous annular anode (7), a pure titanium thin plate cathode (8), a gas outlet (9) of the first-stage absorption tank, an outlet tail gas discharge port (10), an absorption tank liquid discharge port (11), and an absorption tank liquid inlet (12). The first-stage absorption tank (1) and the second-stage absorption tank (2) are both provided with an absorption tank liquid inlet (12) at their upper ends, and with an absorption tank liquid discharge port (11) at their lower ends. The center of the absorption tank is provided with a microporous aeration device (5) near the bottom. The phosphorus-sulfur malodorous gas is discharged through the air guide pipe. The gas is sent to the microporous aeration device (5) of the first stage absorption tank (1) through an air pipe (4), and a flow meter (3) is also arranged on the air pipe (4). A microporous annular anode (7) and a pure titanium thin plate cathode (8) are arranged in the first stage absorption tank (1), and the electrode plate of the pure titanium thin plate cathode (8) is closely attached to the inner wall of the absorption tank. The microporous annular anode (7) is made into a circular ring shape, and the inner side of the mesh anode is closely attached to the microporous aeration device (5); the gas outlet (9) of the first stage absorption tank is connected to the microporous aeration device (5) of the second stage absorption tank (2) through an air pipe, and the top of the second stage absorption tank (2) is also provided with an outlet tail gas discharge port (10).

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