CN116514234B - Stack type electrochemical ammonia recovery device and method loaded with pulsed electric field - Google Patents

Abstract

The invention relates to the technical field of resource recovery, in particular to a stacked electrochemical ammonia recovery device and method loaded with a pulsed electric field, wherein the stacked electrochemical ammonia recovery device includes an anolyte flow chamber and a catholyte flow chamber, an anolyte flow chamber Both sides are sealed by an anion exchange membrane and a hydrophobic gas membrane, and an anode deflector with a porous anode and a flow guide liner is placed inside, and the catholyte flow chamber is sealed by the other side of the hydrophobic gas membrane and an anion exchange membrane, and the inside is placed A cathode deflector with a porous cathode and a diversion liner is provided; the device uses alternately arranged anolyte flow chambers and catholyte flow chambers to achieve the purpose of sewage treatment, regeneration and resource utilization. The acidity and alkalinity can weaken the purging effect of the hydrogen bubbles generated by the hydrogen evolution reaction of the porous cathode on the ammonia gas, reduce the loss of ammonia and secondary environmental pollution, and provide a favorable guide for the technical development of the field of optimizing the electrochemical recovery of ammonia nitrogen.

Description

A stacked electrochemical ammonia recovery device and method loaded with pulsed electric field

technical field

The invention relates to the technical field of resource recovery, in particular to a stacked electrochemical ammonia recovery device and method loaded with a pulse electric field.

Background technique

Ammonia (NH ₃ ), an inorganic compound consisting of one nitrogen atom and three hydrogen atoms, is an important chemical component in a variety of commercial and household products, including fertilizers, refrigerants, stabilizers, and purifiers. Notably, ammonia has recently been proposed as an alternative fuel, providing a suitable storage platform for renewable resources. However, the main industrial process of ammonia production (Haber-bosh process) is energy-intensive, which consumes a lot of fossil energy, causes carbon dioxide emissions, and exacerbates the greenhouse effect. In recent years, there has been increasing interest in exploiting waste ammonia resources, which also avoids the energy requirements of conventional ammonia production. Studies in academia and industry have shown that human urine contains high concentrations of nitrogen, accounting for 75-80% of the ammonia load in urban sewage. Source separation of urine and recovery of ammonia from source separation urine are waste nitrogen resources. An efficient way to reduce the energy consumption required for global ammonia production. Therefore, finding suitable green alternatives for efficient, low-energy, low-emission, and sustainable ammonia production under mild conditions is an urgent scientific challenge to be solved.

Compared with traditional ammonia nitrogen recovery methods such as struvite precipitation and air stripping, electrochemical technology has the advantages of simple operation, strong controllability, economical applicability, and mild reaction conditions. In recent years, electrochemical separation has become more and more popular in the field of ammonia recovery, which can directly convert NH ₄ ⁺ to NH _3(g) through in situ electrochemical reaction, while combining interfacial Joule heating to enhance the extraction and recovery of ammonia, It is expected to realize the efficient recovery of ammonia nitrogen.

However, the existing electrochemical ammonia recovery technology adopts the constant current charging mode to generate OH ^- at the cathode through electrolysis of water, resulting in a high pH value and converting ammonium ions (NH ₄ ⁺ ) into NH _3(g) . However, the alkalized urine may be continuously stripped by the hydrogen bubbles generated by the cathodic hydrogen evolution reaction, resulting in more than 30% ammonia loss in the electrochemical system.

Therefore, it is of great significance and application prospect to develop a more effective ammonia nitrogen recovery method, and the existing technology still needs to be improved and developed.

Contents of the invention

In view of the above-mentioned deficiencies in the prior art, the object of the present invention is to provide a stacked electrochemical ammonia recovery device and method loaded with a pulsed electric field, aiming at solving the problem of low recovery rate faced by traditional electrochemical reactors in recovering ammonia nitrogen.

Technical scheme of the present invention is as follows:

A stacked electrochemical ammonia recovery device loaded with a pulsed electric field, which includes n+1 anolyte flow chambers and n catholyte flow chambers, the anolyte flow chambers and catholyte flow chambers are stacked in sequence, and n is greater than an integer equal to 2;

The two sides of the leftmost anolyte flow chamber are sealed by the left end plate and the anion exchange membrane, and the anode deflector and the porous anode arranged on the anode deflector are arranged inside; the anolyte flow chamber in the middle The two sides are sealed by a hydrophobic gas membrane and an anion exchange membrane, and the inside is provided with an anode deflector and a porous anode on the anode deflector; The right end plate is sealed, and an anode deflector is arranged inside;

Both sides of the catholyte flow chamber are sealed by an anion exchange membrane and a hydrophobic gas membrane, and a cathode deflector and a porous cathode arranged on the cathode deflector are arranged inside;

The upper end and the lower end of the left end plate are respectively provided with an anolyte liquid inlet and a catholyte liquid inlet, and the lower end and the upper end of the right end plate are respectively provided with an anolyte liquid outlet and a catholyte liquid outlet, The anolyte enters the anolyte circulation chamber from the anolyte inlet for circulation, and finally flows out from the anolyte outlet; outflow from the outlet;

The porous anode is connected to the positive pole of the external DC power supply with pulse electric field through the first external metal wire, and the porous cathode is connected to the negative pole of the external DC power supply with pulse electric field through the second external metal wire.

In the stacked electrochemical ammonia recovery device loaded with a pulsed electric field, a silica gel gasket is arranged between the anode deflector, the anion exchange membrane, the cathode deflector and the hydrophobic gas membrane.

The stacked electrochemical ammonia recovery device loaded with a pulsed electric field, wherein the porous anode is any one of ruthenium-iridium porous metal mesh, ruthenium-tantalum porous metal mesh, and iridium-tantalum porous metal mesh, and the weaving density of the porous anode is 30-300 mesh; the porous cathode is any one of carbon cloth, porous metal mesh and porous metal foam, and the weaving density of the porous cathode is 30-300 mesh.

In the stacked electrochemical ammonia recovery device loaded with a pulsed electric field, the material of the hydrophobic gas film is any one of polytetrafluoroethylene, polyvinylidene fluoride and polypropylene.

A method for recovering ammonia based on a stacked electrochemical ammonia recovery device loaded with a pulsed electric field, comprising the steps of:

The catholyte to be treated is input from the catholyte inlet, and the anolyte is input from the anolyte inlet, and the catholyte and the anolyte flow independently in their respective flow channels without mixing with each other;

Control the output pulse current of the external DC power supply so that during the process of catholyte passing through the catholyte flow chamber, NH ₄ ⁺ is converted into NH _3(g) in an alkaline environment where OH ^- is generated when the porous cathode is energized, and then NH _3(g) Diffusion to the anolyte flow chamber through the hydrophobic gas film, and NH _3(g) absorbed and diffused to the anolyte flow chamber by the H ⁺ generated when the porous anode is energized, and finally the ammonia nitrogen is recovered in the form of ammonium salt.

The ammonia recovery method, wherein the catholyte is human urine, and the ammonia nitrogen concentration in the urine is 20−7000 mg/L.

The ammonia recovery method, wherein, the anolyte is tap water or any one of 0-1 M sulfuric acid, hydrochloric acid, nitric acid, carbonic acid and phosphoric acid is added to the tap water.

The ammonia recovery method, wherein, the current density provided by the external DC power supply is 10-100 A m ^-2 , the duty ratio of the pulse current output by the external DC power supply is 0.33-1.00, and the pulse width of the pulse current is 10min-60min.

The ammonia recovery method, wherein, the residence time of the anolyte in the anolyte circulation chamber is 10-60min.

The ammonia recovery method, wherein, the residence time of the catholyte in the catholyte flow chamber is 20-120min.

Beneficial effects: the stacked electrochemical ammonia recovery device provided by the present invention, through the repeated stacking and assembly of the anode deflector provided with the porous anode, the anion exchange membrane, the cathode deflector provided with the porous cathode, and the hydrophobic gas membrane , construct n+1 anolyte flow chambers and n catholyte flow chambers to realize directional conversion and fractionation purification of resources in sewage, and simultaneously achieve the purpose of sewage treatment regeneration and resource utilization. The invention is based on the ammonia recovery method of the stacked electrochemical ammonia recovery device. The pulsed electric field is used to adjust and change the behavior of the electrodes during the electrolysis reaction, especially to affect the development of the current vortex and the evolution of pH. By setting the pulse reasonably The pulse duty cycle and time of the current weaken the purging effect of a large amount of hydrogen generated by the cathode hydrogen evolution reaction on the ammonia, avoiding the loss of ammonia and secondary environmental pollution; at the same time, it can ensure the removal rate of ammonia nitrogen > 99%, and the recovery rate >98%, which greatly improves the efficiency and economy of electrochemical recovery of ammonia, and promotes the development of the field of electrochemical resource recovery.

Description of drawings

Fig. 1 is a schematic structural diagram of a stacked electrochemical ammonia recovery device according to an embodiment of the present invention.

Fig. 2 is a schematic diagram of the electrode liquid flow direction used in the stacked electrochemical ammonia recovery device according to the embodiment of the present invention.

Fig. 3 is a physical diagram of an embodiment of the present invention used in a stacked electrochemical ammonia recovery device.

Fig. 4 is the operating parameters (including voltage, current and pH) in the pulsed electric field mode in Example 1.

FIG. 5 shows the operating parameters (including voltage, current and pH) in the constant current charging mode in Comparative Example 1.

6 is a comparison chart of the ammonia nitrogen recovery results under the pulsed electric field mode in Example 1 and the constant current charging mode in Comparative Example 1.

Reference signs: 1, left end plate, 1', right end plate, 2, anode deflector, 2', cathode deflector, 3, porous anode, 4, diversion liner, 5, porous cathode , 6. Anion exchange membrane, 7. Hydrophobic gas membrane, 8. Anolyte liquid inlet, 9. Catholyte liquid inlet, 10. Anolyte liquid outlet, 11. Catholyte liquid outlet, 12. First Externally connected metal wires, 13. The second externally connected metal wires.

Detailed ways

The present invention provides a stacked electrochemical ammonia recovery device and method loaded with a pulsed electric field. In order to make the purpose, technical solution and effect of the present invention clearer and clearer, the present invention will be further described in detail below. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

Please refer to Fig. 1-Fig. 3, the present invention provides a stacked electrochemical ammonia recovery device loaded with a pulsed electric field, as shown in the figure, it includes n+1 anolyte flow chambers and n catholyte flow chambers, so The above-mentioned anolyte flow chamber and catholyte flow chamber are stacked in sequence, n is an integer greater than or equal to 2; the two sides of the anolyte flow chamber located on the far left are sealed by the left end plate 1 and the anion exchange membrane 6, and an anode is arranged inside Deflector 2 and the guide lining 4 and porous anode 3 arranged on the anode deflector 2; the two sides of the anolyte flow chamber located in the middle are sealed by hydrophobic gas membrane 7 and anion exchange membrane 6, and the inside is provided with The anode deflector 2 and the guide liner 4 and the porous anode 3 arranged on the anode deflector 2; the two sides of the anolyte flow chamber located on the far right are composed of a hydrophobic gas film 7 and a right end plate 1' sealed, with an anode deflector 2 and a deflector liner 4 arranged on the anode deflector 2 inside;

Both sides of the catholyte flow chamber are sealed by an anion exchange membrane 6 and a hydrophobic gas membrane 7, and the inside is provided with a cathode deflector 2' and a deflector liner 4 and a porous cathode arranged on the cathode deflector 2'. 5;

The upper end and the lower end of the left end plate 1 are respectively provided with an anolyte liquid inlet 8 and a catholyte liquid inlet 9, and the lower end and the upper end of the right end plate are respectively provided with an anolyte liquid outlet 10 and a catholyte liquid outlet. A liquid outlet 11, the anolyte enters the anolyte circulation chamber from the anolyte liquid inlet 8 to circulate, and finally flows out from the anolyte liquid outlet 10, and the catholyte enters the catholyte flow chamber from the catholyte liquid inlet 9 Flow on one side, and finally flow out from the catholyte outlet 11;

The porous anode 3 is connected to the positive pole of an external DC power supply with a pulsed electric field through a first external metal wire 12 , and the porous cathode 5 is connected to the negative pole of an external DC power supply with a pulsed electric field through a second external metal wire 13 .

In the present invention, the material of the left end plate and the right end plate is an insulating material with stable chemical properties in the range of pH=1−13. As an example, the material of the left end plate and the right end plate Can be acrylic sheet. In the present invention, the anode guide plate provided with guide liner and porous anode, the anion exchange membrane, the cathode guide plate provided with guide liner and porous cathode, and the hydrophobic gas film are arranged repeatedly in sequence to form n+ 1 anolyte flow chamber and n catholyte flow chambers, adjacent anolyte flow chambers and catholyte flow chambers share the same anion exchange membrane or cathode deflector; in order to prevent anolyte flow chamber and catholyte flow A short flow occurs between the chambers, and there are silica gel gaskets between the anode deflector, anion exchange membrane, cathode deflector and hydrophobic gas membrane, and the outermost part of the stacked electrochemical ammonia recovery device passes through the acrylic end Plates and bolts are sealed, as shown in Figure 3.

In the present invention, the porous anode is any one of ruthenium-iridium porous metal mesh, ruthenium-tantalum porous metal mesh, and iridium-tantalum porous metal mesh, and the weaving density of the porous anode is 30-300 mesh; the porous cathode is carbon Any one of cloth, expanded metal mesh and porous metal foam, the weaving density of the porous cathode is 30-300 mesh.

In the present invention, the material of the hydrophobic air film is any one of polytetrafluoroethylene, polyvinylidene fluoride and polypropylene, but not limited thereto.

The present invention has no special restrictions on the external DC power supply, and any DC power supply or electrochemical workstation that can control the current density can be used; the ruthenium iridium titanium wire is used as the first external metal wire and the second external metal wire to prevent the metal wire from being oxidized by the anode at high potential .

The present invention has no special restrictions on anion exchange membranes, silica gel gaskets and diversion liners, and those that are commercially available or self-developed with corresponding functions can be used. In the present invention, an anion exchange membrane is used to separate the anode guide plate and the cathode guide plate, and the use of a cation exchange membrane or no ion membrane will lead to a significant drop in the ammonia recovery rate.

In the stacked electrochemical ammonia recovery device provided by the present invention, the anode flow deflector provided with the flow guide liner and the porous anode, the anion exchange membrane, the cathode flow guide provided with the flow guide liner and the porous cathode, the hydrophobic The repeated stacking and assembly of gas membranes constructs n+1 anolyte flow chambers and n catholyte flow chambers to realize the directional transformation and fractionation purification of resources in sewage, and simultaneously achieve the purpose of sewage treatment regeneration and resource utilization. The invention is based on the ammonia recovery method of the stacked electrochemical ammonia recovery device. The pulsed electric field is used to adjust and change the behavior of the electrodes during the electrolysis reaction, especially to affect the development of the current vortex and the evolution of pH. By setting the pulse reasonably The pulse duty cycle and time of the current weaken the purging effect of a large amount of hydrogen generated by the cathode hydrogen evolution reaction on the ammonia, avoiding the loss of ammonia and secondary environmental pollution; at the same time, it can ensure the removal rate of ammonia nitrogen > 99%, and the recovery rate >98%, which greatly improves the efficiency and economy of electrochemical recovery of ammonia, and promotes the development of the field of electrochemical resource recovery.

The present invention also provides an ammonia recovery method based on a stacked electrochemical ammonia recovery device loaded with a pulsed electric field, which includes the steps of:

S10, input the catholyte to be treated from the catholyte inlet, and input the anolyte from the anolyte inlet, the catholyte and the anolyte flow independently in their respective channels without mixing with each other;

In this embodiment, the catholyte is human urine, and the ammonia nitrogen concentration of the urine is 20−7000 mg/L, such as 20 mg/L, 50 mg/L, 100 mg/L, 200 mg/L, 500 mg /L, 1000mg/L, 2000mg/L, 3000mg/L, 4000mg/L, 5000mg/L, 6000mg/L, 7000mg/L, more preferably 300-4000 mg/L, the ammonia nitrogen concentration of the urine of the present invention is represented by N In terms of elements; the anolyte is tap water or any one of 0-1 M sulfuric acid, hydrochloric acid, nitric acid, carbonic acid and phosphoric acid added to the tap water. In this embodiment, the catholyte is input from the catholyte inlet, flows through the catholyte flow chamber and flows out from the cathode liquid outlet, and the anolyte is input from the anolyte liquid inlet, flows through the anolyte flow chamber Then it flows out from the anode liquid outlet.

S20. Controlling the output pulse current of the external DC power supply, so that during the catholyte passing through the catholyte flow chamber, NH ₄ ⁺ is converted into NH _3(g) in an alkaline environment where ^OH- is generated when the porous cathode is energized, and then NH _{3( g)} Diffusion to the anolyte flow chamber through the hydrophobic gas film, and NH _3(g) absorbed and diffused to the anolyte flow chamber by the H ⁺ generated when the porous anode is energized, and finally the ammonia nitrogen is recovered in the form of ammonium salt.

In this embodiment, the external DC power supply outputs a pulsed current. During the process of the catholyte passing through the catholyte flow chamber composed of an anion exchange membrane and ^a hydrophobic gas membrane, NH ₄ ⁺ is converted into NH _3(g) , and then NH _3(g) diffuses to the other side of the hydrophobic gas membrane, which is the anolyte flow chamber composed of the hydrophobic gas membrane and the next layer of anion exchange membrane 6; the anode The electrochemical reaction of the porous anode in the liquid flow chamber produces a large amount of H ⁺ , and the H ⁺ absorbs the NH _{3 (g)} diffused from the catholyte flow chamber to the anolyte flow chamber, and finally the ammonia nitrogen is recovered in the form of ammonium salt.

In this embodiment, when the external DC power supply is energized, the pH of the anode zone decreases due to electrochemical reactions, and the pH of the cathode zone rises; when the external DC power supply is discharged, because H ⁺ and OH ^- are constantly consumed, they cannot be replenished in time , so that the pH of the anode area rises, and the pH of the cathode area decreases. Therefore, in this embodiment, the charging and discharging time can be reasonably set to avoid the dissipation of ammonia caused by the high pH of the cathode area, or the decrease of the ammonia recovery efficiency caused by the low pH.

That is to say, in this embodiment, the pH value of the cathode region can be regulated by applying a pulsed electric field, weakening the purging effect of a large number of hydrogen bubbles on the ammonia gas due to the hydrogen evolution reaction at the cathode, reducing the loss of ammonia and secondary environmental pollution, and realizing the electric Economical and efficient chemical recovery of ammonia nitrogen.

In some embodiments, the current density provided by the external DC power supply is 10-100 A m ^-2 , such as 10, 20, 40, 60, 80, 100 A m ^-2 , more preferably 30−90 A m ^-2 ; the duty ratio of the pulse current output by the external DC power supply is 0.33-1.00, such as 0.33, 0.50, 0.67, 0.83, 1.00, more preferably 0.50−0.67; the pulse width of the pulse current is 10min-60min , such as 10 min, 20 min, 30 min, 40 min, 50 min, 60 min, more preferably 20−40 min.

In some embodiments, the residence time of the anolyte in the anolyte circulation chamber is 10-60min, such as 10min, 20min, 40min, 60min, more preferably 10-30min, the anolyte adopts circulation flow, and the ammonia enrichment at the anode. The residence time of the catholyte in the catholyte circulation chamber is 20-120min. For example, it can be 20 min, 40 min, 60 min, 120 min, more preferably 50−100 min, and the catholyte adopts continuous flow.

The present invention will be further explained below by specific embodiment:

Example 1

A method for recovering ammonia based on a stacked electrochemical ammonia recovery device loaded with a pulsed electric field, comprising the steps of:

1. Input the catholyte to be treated from the catholyte inlet, and input the anolyte from the anolyte inlet, the catholyte and the anolyte flow independently in their respective channels without mixing with each other; the catholyte It is human urine, and the ammonia nitrogen concentration of the urine is 4000 mg/L; the anolyte is tap water.

2. As shown in Figure 4, control the output pulse current of the external DC power supply, set the current density provided by the external DC power supply to 80 A m ^-2 , the duty cycle of the pulse current is 0.67, and the pulse width of the pulse current is 40 min; so that the cathode During the process of liquid passing through the catholyte flow chamber, NH ₄ ⁺ is converted into NH _3(g) in the alkaline environment where OH ^- is generated when the porous cathode is energized, and then NH _3(g) diffuses into the anolyte flow through the hydrophobic gas film The H ⁺ generated when the porous anode is energized absorbs the NH _3(g) that diffuses into the anolyte flow chamber, and finally the ammonia nitrogen is recovered in the form of ammonium salt. In this embodiment, the behavior of the electrodes is adjusted by loading a pulsed electric field to achieve effective recovery of ammonia nitrogen, and at the same time weaken the purging effect of hydrogen gas generated by the cathode hydrogen evolution reaction on ammonia to reduce the loss of ammonia nitrogen.

Comparative example 1

A method for recovering ammonia based on a stacked electrochemical ammonia recovery device in constant current charging mode, comprising the steps of:

1. The catholyte to be treated is input from the catholyte inlet, and the anolyte is input from the anolyte inlet. The catholyte and the anolyte flow independently in their respective channels without mixing with each other. The catholyte It is human urine, and the ammonia nitrogen concentration of the urine is 4000 mg/L; the anolyte is tap water;

2. As shown in Figure 5, control the external DC power supply to output a constant current, set the current density provided by the external DC power supply to 53.33 A m ^-2 , so that during the process of catholyte passing through the catholyte flow chamber, NH ₄ ⁺ is in the porous cathode When energized, OH ^- is converted to NH _3(g) in an alkaline environment, and then NH _3(g) diffuses into the anolyte flow chamber through the hydrophobic gas film, and absorbs and diffuses into the anolyte through the H ⁺ generated when the porous anode is energized. The NH _3(g) in the flow-through chamber finally causes ammonia nitrogen to be recovered in the form of ammonium salt. Comparing the operating data of Example 1 and Comparative Example 1, it can be found that the constant current intensity is 2/3 times of the pulse current intensity, the charging time is 1.5 times of the pulse electric field, and the same experimental time consumes the same energy.

Calculate the ammonia nitrogen recovery rate by the method of embodiment 1 and comparative example 1, its result is as shown in Figure 6, can find out from Figure 6 that the pulsed electric field of different current intensity and constant electric field, consume equal energy consumption, the ammonia nitrogen recovery rate of pulsed electric field 20% increase. The reason is that the intermittent charging and discharging of the pulsed electric field has an important impact on the development of the current vortex and the evolution of the pH, avoiding continuous hydrogen production after long-term charging, weakening the purging effect of hydrogen bubbles on ammonia, reducing the loss of ammonia nitrogen, and avoiding secondary environmental pollution .

It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" or "comprising" does not exclude the presence of elements or steps not listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The use of the words first, second, third, etc. does not indicate any order and these words may be interpreted as names.

All features disclosed in this specification, except mutually exclusive features, may be combined in any way.

Any feature disclosed in this specification (including any appended claims, abstract and drawings), unless expressly stated otherwise, may be replaced by alternative features which are equivalent or serve a similar purpose. That is, unless expressly stated otherwise, each feature is one example only of a series of equivalent or similar features.

The present invention is not limited to the foregoing specific embodiments. The present invention extends to any new feature or any new combination disclosed in this specification, and any new method or process step or any new combination disclosed.

Claims (10)

1. The stack type electrochemical ammonia recovery device loaded with the pulsed electric field is characterized by comprising n+1 anolyte flow chambers and n catholyte flow chambers, wherein the anolyte flow chambers and the catholyte flow chambers are sequentially stacked, and n is an integer greater than or equal to 2;

the two sides of the anode liquid flow chamber at the leftmost side are sealed by a left end plate and an anion exchange membrane, and an anode guide plate and a porous anode arranged on the anode guide plate are arranged in the anode liquid flow chamber; the two sides of the anolyte flow chamber in the middle are sealed by a hydrophobic air film and an anion exchange film, and an anode guide plate and a porous anode arranged on the anode guide plate are arranged in the anolyte flow chamber; two sides of the anode liquid flow chamber at the rightmost side are sealed by a hydrophobic air film and a right end plate, and a guide plate is arranged in the anode liquid flow chamber;

both sides of the catholyte flow chamber are sealed by an anion exchange membrane and a hydrophobic air film, and a cathode guide plate and a porous cathode arranged on the cathode guide plate are arranged in the catholyte flow chamber;

the upper end and the lower end of the left side end plate are respectively provided with an anolyte inlet and a catholyte inlet, the lower end and the upper end of the right side end plate are respectively provided with an anolyte outlet and a catholyte outlet, anolyte enters the anolyte circulation chamber from the anolyte inlet for circulation and flows out of the anolyte outlet at last, catholyte enters the catholyte circulation chamber from the catholyte inlet for unilateral flow, and finally flows out of the catholyte outlet;

the porous anode is connected with an anode of an external direct current power supply for loading the pulse electric field through a first external metal wire, and the porous cathode is connected with a cathode of the external direct current power supply for loading the pulse electric field through a second external metal wire.

2. The pulsed electric field loaded stacked electrochemical ammonia recovery device of claim 1, wherein silica gel gaskets are disposed between the anode baffle, the anion exchange membrane, the cathode baffle, and the hydrophobic gas membrane.

3. The pulse electric field loaded stack type electrochemical ammonia recovery device according to claim 1, wherein the porous anode is any one of ruthenium iridium porous metal mesh, ruthenium tantalum porous metal mesh and iridium tantalum porous metal mesh, and the weaving density of the porous anode is 30-300 meshes; the porous cathode is any one of carbon cloth, porous metal net and porous foam metal, and the weaving density of the porous cathode is 30-300 meshes.

4. The pulse electric field loaded stacked electrochemical ammonia recovery device of claim 1, wherein the hydrophobic gas membrane is any one of polytetrafluoroethylene, polyvinylidene fluoride, and polypropylene.

5. An ammonia recovery method based on a pulsed electric field loaded stacked electrochemical ammonia recovery device of any one of claims 1-4, comprising the steps of:

inputting catholyte to be treated from a catholyte inlet, inputting anolyte from an anolyte inlet, and enabling the catholyte and the anolyte to flow independently in respective flow passages without mixing each other;

controlling an external direct current power supply to output pulse current, so that NH (NH) is generated in the process of enabling catholyte to pass through the catholyte circulation chamber ₄ ⁺ OH formation upon energization of a porous cathode ^- Is converted to NH in alkaline environment ₃ Then NH ₃ Through diffusion of a hydrophobic membrane into an anolyte flow cell, H is generated when the porous anode is energized ⁺ Absorbing NH diffused into anolyte flow-through chamber ₃ Finally, ammonia nitrogen is recovered in the form of ammonium salt.

6. The method for recovering ammonia according to claim 5, wherein the catholyte is human urine, and the ammonia nitrogen concentration of the urine is 20-7000 mg/L.

7. The method for recovering ammonia according to claim 5, wherein the anolyte is tap water or any one of sulfuric acid, hydrochloric acid, nitric acid, carbonic acid and phosphoric acid added to tap water in an amount of 0 to 1M.

8. The method for recovering ammonia according to claim 5, wherein the current density supplied by the external DC power source is 10 to 100A m ^-2 The duty ratio of the pulse current output by the external direct current power supply is 0.33-1.00, and the pulse width of the pulse current is 10-60min.

9. The method of ammonia recovery according to claim 5, wherein the anolyte has a residence time in the anolyte pass chamber of from 10 to 60 minutes.

10. The method of ammonia recovery according to claim 5, wherein the catholyte has a residence time of 20-120min in the catholyte flow chamber.