CN114524493B - Ammonia recovery device and method for electrochemically treating nitrate wastewater - Google Patents

Abstract

The invention provides an ammonia recovery device for electrochemically treating nitrate wastewater, which includes an electrochemical reactor, an anode chamber and a cathode chamber are arranged in the electrochemical reactor, and the anode chamber and the cathode chamber pass through a proton exchange membrane Separately arranged, the electrochemical reactor is also provided with an ammonia recovery chamber; the anode chamber, cathode chamber and the ammonia recovery chamber are arranged adjacent to each other in sequence, the anode chamber is provided with a counter electrode, and the cathode chamber and the ammonia recovery chamber are arranged adjacent to each other. The ammonia recovery chamber is separated by a diaphragm, and the diaphragm is composed of an electrode material and a waterproof and breathable material; the ammonia recovery device also includes an electrolyte storage tank, a nitrate storage tank, and an ammonia absorption liquid storage tank for forming an external circulation , and a constant flow pump. The invention can convert high-concentration nitrate into ammonium ions, and can directly recover available ammonium salt products, and directly obtain high-purity resource-based substances in a clean and environment-friendly manner while purifying high-concentration nitrate wastewater.

Description

An ammonia recovery device and method for electrochemically treating nitrate wastewater

technical field

The invention relates to the field of ammonia recovery by electrochemical reduction of nitrate, in particular to an ammonia recovery device and method for electrochemically treating nitrate wastewater.

Background technique

Nitrogen is one of the chemical elements necessary to maintain life activities. Nitrogen in water mainly exists in two forms: organic nitrogen and inorganic nitrogen. The main representatives of organic nitrogen are compounds such as protein and urea, and inorganic nitrogen includes ammonia nitrogen (NH ₄ ⁺ or NH ₃ ), nitrate (NO ₃ ^- ), nitrite (NO ₂ ^- ), nitrogen (N ₂ ), etc. The transfer and transformation of nitrogen in nature between the environment and various organisms constitutes the nitrogen cycle, but due to the large amount of nitrogen-containing wastewater discharged without treatment or treatment that fails to meet the standards in industrial production, the nitrogen cycle is destroyed, thereby causing nitrogen pollution. Among them, high-concentration NO ₃ ^-wastewater is one of the main causes of nitrogen cycle imbalance. The wastewater produced by iron and steel smelting, electroplating, chemical fertilizer, nuclear fuel and electronic components all contains high concentration of NO ₃ ^- . For example, in the nuclear industry, the concentration ^of NO ₃ in the waste water used to clean metal devices with concentrated nitric acid is as high as 50,000 mg N/L. Therefore, how to effectively treat the high-concentration NO ₃ ^-wastewater produced in industry has become one of the difficulties in the field of water pollution control.

Ammonia (NH ₃ ) is an indispensable raw material for the manufacture of chemical products such as fertilizers _, medicines, and dyes. It has become a Become a potential green energy carrier and fuel. At present, the _synthesis of NH mainly relies on the Haber-Bosch (Haber-Bosch) process, and the global annual production total is about 200 million tons, which is the second largest chemical product in the world. However, this method has harsh reaction conditions (high temperature and pressure 300-500°C, 200-300 atm), high energy consumption (1-2% of global energy consumption), and emits a large amount of greenhouse gases such as CO ₂ and CH ₄ . According to the chemical industry standard "HG/T 4487-2012" of the People's Republic of China, the carbon emission per unit product NH ₃ is about 1.5tCO ₂ /tNH ₃ . According to the preliminary statistics of the Ammonia Energy Association, the global annual production of NH ₃ emits 1.6% of the global carbon emissions.

It can be seen that the method of converting NO ₃ ^- in nitrate wastewater into NH ₄ ⁺ and then recovering NH ₃ can not only complete the treatment of nitrate wastewater, but also obtain NH ₃ in a clean way. At present, although there have been related studies that use electrochemical reactions to convert NO ₃ ^- into NH ₄ ⁺ , the existing studies mainly focus on the selectivity of NH ₄ ⁺ , and rarely involve the recovery and utilization of NH ₃ , and, The effect of the existing research on recovering ammonia from high-concentration nitrate wastewater is not ideal.

In view of this, it is necessary to provide an ammonia recovery device and method for electrochemically treating nitrate wastewater, to solve or at least alleviate the above-mentioned disadvantages of ammonia recovery inconvenience and high-concentration nitrate wastewater treatment difficulties.

Contents of the invention

The main purpose of the present invention is to provide an ammonia recovery device and method for electrochemically treating nitrate wastewater, aiming to solve the above-mentioned technical problems of inconvenient ammonia recovery and difficult treatment of high-concentration nitrate wastewater.

To achieve the above object, the present invention provides an ammonia recovery device for electrochemically treating nitrate wastewater, comprising an electrochemical reactor, an anode chamber and a cathode chamber are arranged in the electrochemical reactor, and the anode chamber and the The cathode chamber is separated by a proton exchange membrane, and the electrochemical reactor is also provided with an ammonia recovery chamber;

The anode chamber, the cathode chamber and the ammonia recovery chamber are adjacently arranged successively, the anode chamber is provided with a counter electrode, the cathode chamber is separated from the ammonia recovery chamber by a diaphragm, and the diaphragm includes an air electrode;

The ammonia recovery device also includes an electrolyte storage tank, a nitrate storage tank, an ammonia absorption liquid storage tank, and a constant flow pump;

Wherein, the liquid outlet of the electrolyte storage tank is communicated with the liquid inlet of the anode chamber through the constant flow pump; the liquid outlet of the nitrate storage tank is connected with the cathode through the constant flow pump. The liquid inlet of the chamber is connected; the liquid outlet of the ammonia absorption liquid storage tank is connected with the liquid inlet of the ammonia recovery chamber through the constant flow pump.

Further, the counter electrode is a shape-stable anode, and the shape-stable anode includes one of lead oxide, iridium oxide, ruthenium oxide and boron-doped diamond film electrodes.

Further, the cathode chamber is provided with a reference electrode; the reference electrode includes one of silver silver chloride, saturated calomel and a standard hydrogen electrode.

Further, the preparation process of the air electrode includes: mixing the material with electrochemical reduction nitrate activity with acetylene black and evenly coating it on the surface of the waterproof and breathable membrane to obtain the air electrode;

Wherein, the material with electrochemical reduction nitrate activity includes one or more of ilmenite, cobalt phosphide, nano-zero-valent iron, tricobalt tetroxide, nano-zero-valent copper and titanium dioxide.

Further, the anolyte is stored in the electrolyte storage tank, and the anolyte includes sodium sulfate solution.

Further, nitrate wastewater is stored in the nitrate storage tank, and the concentration range of nitrate in the nitrate wastewater is 500-50000mg N/L.

Further, the ammonia absorption liquid is stored in the ammonia absorption liquid storage tank, and the ammonia absorption liquid includes one of sulfuric acid solution, hydrochloric acid solution and carbonic acid solution.

Further, the liquid inlet of the electrolyte storage tank is communicated with the liquid outlet of the anode chamber; the liquid inlet of the nitrate storage tank is communicated with the liquid outlet of the cathode chamber; the ammonia The liquid inlet of the absorption liquid storage tank communicates with the liquid outlet of the ammonia recovery chamber.

Further, the liquid inlet of the anode chamber is arranged opposite to the liquid outlet, and the height of the liquid inlet of the anode chamber is lower than the liquid outlet;

The liquid inlet of the cathode chamber is opposite to the liquid outlet, and the height of the liquid inlet of the cathode chamber is lower than the liquid outlet;

The liquid inlet of the ammonia recovery chamber is opposite to the liquid outlet, and the height of the liquid inlet of the ammonia recovery chamber is lower than the liquid outlet.

The present invention also provides a method for ammonia recovery, using the ammonia recovery device as described in any one of the above to reclaim ammonia from nitrate wastewater.

Compared with the prior art, the present invention has the following advantages:

The invention can convert high-concentration nitrate into ammonium salt products that can be directly recycled, and directly obtain high-purity resource-based substances in a clean and environmentally friendly manner while purifying high-concentration nitrate wastewater. specifically:

1. The present invention combines the diaphragm and the ammonia absorption chamber. Because the diaphragm is conductive and has the performance of electrochemically reducing nitrate to ammonium ion, it can convert nitrate into ammonium under the condition of electrochemical reaction. ions, and with the help of a local increase in pH to promote the conversion of ammonium ions into ammonia gas, so that a pressure difference is formed on both sides of the diaphragm, so that ammonia gas enters the ammonia recovery chamber from the cathode chamber during the continuous generation process, and then the ammonia gas is recovered Indoor conversion to ammonia salt products.

2. The present invention combines the external circulation mode with the electrochemical reactor, and the constant flow pump pumps the electrolyte, nitrate waste water and ammonia absorption liquid in the storage tank into the corresponding electrolytic cell, and directly returns to the electrolytic cell from the upper liquid outlet. The storage tank can keep the solution in a flowing and uniform state, eliminating the need for stirring, reducing the equipment footprint, and saving energy. In addition, the nitrate solution in the cathode chamber has been in a constant flow state, similar to the capacitive deionization model, and the ammonium ions generated by electrochemical denitrification under the electric field drive can move to the surface of the conductive waterproof gas-permeable membrane, which is conducive to the removal of ammonia. recovery; moreover, the ammonia recovery chamber is in a state of constant circulation, which can continuously absorb the ammonia gas entering the ammonia recovery chamber to ensure that there is a continuous pressure difference on both sides of the diaphragm.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those skilled in the art, other drawings can also be obtained according to the structures shown in these drawings without creative work.

Fig. 1 is the module schematic diagram of ammonia recovery device in an embodiment of the present invention;

Fig. 2 is the structural representation of electrochemical reactor in an embodiment of the present invention;

Fig. 3 is the structural representation of electrochemical reactor in another embodiment of the present invention (counter electrode and reference electrode are not shown);

Fig. 4 is a data effect diagram of treating high-concentration nitrate wastewater in Example 2 of the present invention.

Reference signs: 1, electrochemical reactor; 2, anode chamber; 3, counter electrode; 4, proton exchange membrane; 5, cathode chamber; 6, reference electrode; 7, diaphragm; 8, ammonia recovery chamber; 9, Electrolyte storage tank; 10. Nitrate storage tank; 11. Ammonia absorption liquid storage tank; 12. Constant flow pump; 13. The first shell; 14. The first gasket; 15. The second gasket; 16. The second gasket Two casings; 17, the third gasket; 18, the fourth gasket; 19, the third casing.

The realization of the object of the present invention, function characteristic and advantage will be described further with reference to accompanying drawing in conjunction with embodiment.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Way. Based on the implementation modes in the present invention, all other implementation modes obtained by persons of ordinary skill in the art without creative work, all belong to the protection scope of the present invention.

It should be noted that all directional indications (such as up, down, ...) in the embodiments of the present invention are only used to explain the relative positional relationship, motion, etc. , if the specific attitude changes, the directional indication changes accordingly.

In addition, descriptions such as "first", "second" and so on in the present invention are only for description purposes, and cannot be understood as indicating or implying their relative importance or implicitly specifying the quantity of indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of these features.

Moreover, the technical solutions among the various embodiments of the present invention can be combined with each other, but it must be based on the realization of those skilled in the art. When the combination of technical solutions is contradictory or cannot be realized, it should be considered that the combination of technical solutions Does not exist, nor within the scope of protection required by the present invention.

It should be noted that the existing technology is lacking in the treatment of high-concentration nitrates. At the same time, the preparation of electrode materials generally used for the electrochemical reduction of nitrates to recover ammonia is relatively complicated and costly, and there is still a certain distance from industrialization. research space.

In order to reclaim _NH resources while realizing the purification of high-concentration nitrate wastewater, as shown in FIGS. The electrochemical reactor 1 is provided with an anode chamber 2 and a cathode chamber 5 , and the anode chamber 2 and the cathode chamber 5 are separated by a proton exchange membrane 4 .

On this basis, in order to realize the recovery of ammonia, the ammonia recovery chamber 8 is also provided in the described electrochemical reactor 1, to obtain the ammonium salt product in the described ammonia recovery chamber 8.

In order to ensure the carrying out of the electrochemical reaction, the anode chamber 2, the cathode chamber 5 and the ammonia recovery chamber 8 are adjacently arranged in sequence, and the anode chamber 2 is provided with a counter electrode 3. The cathode chamber 5 is separated from the ammonia recovery chamber 8 by a diaphragm 7, and the diaphragm 7 is an air electrode mainly composed of an electrode material and a waterproof and breathable material. Of course, in the process of carrying out the electrochemical reaction, the inside of the electrochemical reaction device needs to be isolated from the outside, and at the same time, an external power supply device needs to be introduced for power supply, and the electrochemical reaction device is carried out by applying a constant voltage or constant current drive by using an external power supply device. Research on treating high-concentration nitrate wastewater and recovering ammonia; wherein, the power supply device can be an electrochemical workstation, a stabilized power supply, a DC power supply or a transverse potentiometer.

It should be noted that the counter electrode 3 acts as an anode, and the diaphragm 7 can also make ammonia enter the ammonia recovery chamber 8 smoothly on the basis of serving as a cathode (working electrode). , the pH at the diaphragm 7 will rise to 10 or even higher, so the ammonium ions converted by nitrate will generate a large amount of ammonia gas at the diaphragm 7 (the side near the cathode chamber 5), making the diaphragm A pressure difference is formed on both sides of the 7, thereby ensuring that ammonia passes through the diaphragm 7 and enters the ammonia recovery chamber 8.

In addition, in order to improve the efficiency of reaction and recovery while reducing equipment footprint and saving energy, the ammonia recovery device also includes an electrolyte storage tank 9, a nitrate storage tank 10, an ammonia absorption liquid storage tank 11, and a constant flow Pump 12; wherein, the liquid outlet portion of the electrolyte storage tank 9 is communicated with the liquid inlet port of the anode chamber 2 through the constant flow pump 12, and the liquid inlet portion of the electrolyte storage tank 9 is connected to the liquid inlet port of the anode chamber 2. The liquid outlet of the anode chamber 2 is communicated with and arranged; the liquid outlet of the nitrate storage tank 10 is communicated with the liquid inlet of the cathode chamber 5 by the constant flow pump 12, and the inlet of the nitrate storage tank 10 The liquid part is communicated with the liquid outlet of the cathode chamber 5; the liquid outlet of the ammonia absorption liquid storage tank 11 is communicated with the liquid inlet of the ammonia recovery chamber 8 through the constant flow pump 12, and the The liquid inlet portion of the ammonia absorption liquid storage tank 11 communicates with the liquid outlet of the ammonia recovery chamber 8.

It should be noted that, under the action of the constant flow pump 12, not only can the substances in the anode chamber 2, the cathode chamber 5 and the ammonia recovery chamber 8 be circulated, thereby stirring and The effect of changing the liquid; and, because the material in the cathode chamber 5 is in the flow process, under the drive of the electric field, the ammonium ion generated in the cathode chamber 5 is easy to move to the surface of the diaphragm 7 in an orientation, Ammonia is generated under the action of high pH, ensuring that the diaphragm 7 has a high pressure on one side of the cathode chamber 5, and at the same time, because the ammonia entering the ammonia recovery chamber 8 will be converted into ammonia salt Participate in circulating flow after product, therefore, can guarantee that the ammonia gas on one side of described cathode chamber 5 continuously enters described ammonia recovery chamber 8, and is converted into required ammonium salt product.

It should also be noted that since the conversion of ammonium ions to ammonia belongs to a reversible reaction, under the above conditions, ammonia continues to enter the ammonia recovery chamber 8, which can further ensure the conversion efficiency of the ammonium ions to ammonia. Thereby, the recovery efficiency and recovery speed of ammonia are improved, and the formation of the above-mentioned conditions can be ensured.

The specific process in the above-mentioned embodiment is: on the basis of electrochemical reaction, the nitrate ions entering the cathode chamber 5 will be converted into ammonium ions; value rises, which is beneficial to the conversion of ammonium ions to ammonia; when ammonium ions start to convert to ammonia, a pressure difference will be formed on both sides of the diaphragm 7, so that the converted ammonia enters the ammonia recovery chamber 8, and The sulfuric acid solution and other substances circulating in the ammonia recovery chamber 8 are converted into ammonia salt products, thereby realizing the purification of nitrate wastewater and the acquisition of ammonia products.

As an illustration to the counter electrode 3, the counter electrode 3 is a shape-stable anode, and the shape-stable anode includes one of lead oxide, iridium oxide, ruthenium oxide and boron-doped diamond film electrodes.

As an illustration to the electrochemical reactor 1, the electrochemical reactor 1 can be a three-electrode system, and when reacting with the three-electrode system, a reference electrode 6 can be set in the cathode chamber 5. Described reference electrode 6 comprises wherein a kind of in silver silver chloride, saturated calomel and standard hydrogen electrode.

As an illustration to the diaphragm 7, the diaphragm 7 can be described as a waterproof and gas-permeable membrane that is conductive and has the performance of electrochemically reducing nitrate to ammonium ions, i.e. an air electrode. The preparation process of the air electrode includes: mixing the material with electrochemical reduction nitrate activity with acetylene black and evenly coating it on the surface of the waterproof and gas-permeable membrane to obtain the air electrode; wherein, the electrochemical reduction nitrate Active materials include one or more of ilmenite, cobalt phosphide, nano-zero-valent iron, tricobalt tetroxide, nano-zero-valent copper, and titanium dioxide.

Exemplarily, the preparation process of the diaphragm 7 may include: coating a mixture of ilmenite powder and acetylene black on the surface of polytetrafluoroethylene to obtain the diaphragm 7. Because the diaphragm 7 contains ilmenite, it has high stability, corrosion resistance and electrical conductivity, and can not only purify the low-concentration nitrate wastewater, but also purify high-concentration wastewater. For example, it is possible to purify nitrate wastewater with a nitrate concentration range of 500-50000mg N/L and obtain ammonium salt products.

As an illustration of the electrolyte storage tank 9, the nitrate storage tank 10, and the ammonia absorption liquid storage tank 11, an anolyte is stored in the electrolyte storage tank 9, and the anolyte Including sodium sulfate solution. Nitrate waste water is stored in the nitrate storage tank 10, and the concentration range of nitrate in the nitrate waste water can be 500-50000mg N/L. The ammonia absorption liquid storage tank 11 is stored with ammonia absorption liquid, and the ammonia absorption liquid includes one of sulfuric acid solution, hydrochloric acid solution and carbonic acid solution.

As a preferred version of the above embodiment, in order to ensure the circulation of liquid, the liquid inlet of the anode chamber 2 is opposite to the liquid outlet, and the height of the liquid inlet of the anode chamber 2 is lower than the liquid outlet ; The liquid inlet and the liquid outlet of the cathode chamber 5 are oppositely arranged, and the height of the liquid inlet of the cathode chamber 5 is lower than the liquid outlet; the liquid inlet and the liquid outlet of the ammonia recovery chamber 8 It is arranged oppositely, and the height of the liquid inlet of the said ammonia recovery chamber 8 is lower than the liquid outlet. Wherein, for the cathode chamber 5, in addition to ensuring the circulating flow of the liquid, the liquid inlet of the cathode chamber 5 is lower than the liquid outlet, and ammonia gas can also be allowed to enter the chamber during the movement from bottom to top. Ammonia recovery, improve recovery efficiency.

The present invention also provides a method for ammonia recovery, using the ammonia recovery device as described in any of the above embodiments to recover ammonia from nitrate wastewater.

In order to facilitate the understanding of the above-mentioned implementation manner, an example is given to illustrate:

Example 1

Shown with reference to Fig. 1-3, a kind of ammonia recovery device comprises electrolyte storage tank 9, nitrate storage tank 10, ammonia absorption liquid storage tank 11, constant flow pump 12, and electrochemical reactor 1.

Described electrochemical reactor 1 comprises the first shell 13, the second shell 16 and the 3rd shell 19 that are arranged laterally successively, and described first shell 13 is concavely formed with anode chamber 2 laterally, The second casing 16 is formed with a cathode chamber 5 that runs through it laterally, and the third casing 19 is concavely formed with an ammonia recovery chamber 8 in the lateral direction, and the anode chamber 2 and the ammonia recovery chamber 8 are relatively arranged. , the anode chamber 2 is provided with a counter electrode 3, and the cathode chamber 5 is provided with a reference electrode 6.

The first gasket 14, the proton exchange membrane 4 and the second gasket 15 are arranged successively between the first casing 13 and the second casing 16; the second casing 16 and the third casing The third gasket 17, the diaphragm 7 (i.e. the air electrode) and the fourth gasket 18 are sequentially arranged between the body 19, the first gasket 14, the second gasket 15, the third gasket Both the sheet 17 and the fourth gasket 18 are formed with transversely penetrating passages, so as to facilitate the electrochemical reaction and the movement of substances.

The first housing 13, the first gasket 14, the second gasket 15, the proton exchange membrane 4, the second housing 16, the third gasket 17, the diaphragm 7. The fourth gasket 18 and the third housing 19 are hermetically connected by fasteners.

The lower parts of the anode chamber 2, the cathode chamber 5 and the ammonia recovery chamber 8 are all provided with a liquid inlet, and the upper parts are all provided with a liquid outlet; the liquid inlet of the anode chamber 2 passes through the constant current The pump 12 is communicated with the electrolyte storage tank 9, and the liquid outlet of the anode chamber 2 is also communicated with the electrolyte storage tank; the liquid inlet of the cathode chamber 5 is connected with the constant flow pump 12 The nitrate storage tank 10 is communicated, and the liquid outlet of the cathode chamber 5 is also communicated with the nitrate storage tank; the liquid inlet of the ammonia recovery chamber 8 is connected to the The ammonia absorption liquid storage tank 11 is communicated with and arranged, and the liquid outlet of the ammonia recovery chamber 8 is also communicated with the ammonia absorption liquid storage tank.

Example 2

Adopt the ammonia recovery device among the embodiment 1 to carry out the experiment of electrochemical treatment high-concentration nitrate wastewater reclaiming ammonia.

Wherein, the anolyte adopts 0.1M sodium sulfate (50mL); the high-concentration nitrate wastewater adopts the simulated nitrate wastewater (50mL) configured by ultrapure water, and the simulated nitrate wastewater contains 0.1M sodium sulfate and 1000mg N/L Nitrate; Ammonia absorption solution adopts 0.1M sulfuric acid (50mL); Shape stability anode adopts ruthenium dioxide (4cm * 4cm); Reference electrode 6 selects silver silver chloride for use.

The preparation process of diaphragm 7 (4cm×4cm) is as follows: 200mg ilmenite powder is mixed with 25mg acetylene black to obtain a mixture; the mixture is dispersed in 5mL 10g/L polyvinylidene fluoride nitrogen-nitrogen dimethyl pyrrolidone solution , Obtain the black slurry; The black slurry is evenly coated on the surface of the polytetrafluoroethylene waterproof and breathable membrane by a sprayer to obtain the diaphragm (i.e. the air electrode).

The flow rate of the constant flow pump 12 is 120 μL/min, and a constant voltage of -1.9Vvs.Ag/AgCl is applied to the diaphragm by a Metrohm electrochemical workstation.

Experimental result as shown in Figure 4, after electrolysis reaction 10h, the removal rate of nitrate, the generation rate of ammonium ion and the ammonia recovery rate are respectively 91.1%, 77.6% and 85.9%; Wherein, the generation rate of ammonium ion Refers to: the conversion rate of ammonium ions in the degraded nitrate; the recovery rate of ammonia refers to the recovery rate of ammonia in the converted ammonium ions. It can be seen that the ammonia recovery device and method provided by the present invention can simultaneously realize the dual goals of processing high-concentration nitrate wastewater and reclaiming ammonia.

Among the above-mentioned technical schemes of the present invention, the above are only preferred embodiments of the present invention, and are not intended to limit the scope of patents of the present invention. Under the technical conception of the present invention, the equivalent structures made by utilizing the description of the present invention and the contents of the accompanying drawings Transformation, or direct/indirect use in other related technical fields are all included in the patent protection scope of the present invention.

Claims (9)

1. An ammonia recovery device for electrochemically treating nitrate waste water, comprising an electrochemical reactor, wherein an anode chamber and a cathode chamber are provided in the electrochemical reactor, and the anode chamber and the cathode chamber are separated by a proton exchange membrane Setting, it is characterized in that, the ammonia recovery chamber is also arranged in the described electrochemical reactor; The anode chamber, the cathode chamber and the ammonia recovery chamber are arranged adjacently in sequence, the anode chamber is provided with a counter electrode, the cathode chamber and the ammonia recovery chamber are separated by a diaphragm, and the diaphragm includes air electrode; The preparation process of the air electrode includes: mixing a material with electrochemical reduction nitrate activity with acetylene black and then uniformly coating the surface of the waterproof and breathable membrane to obtain the air electrode; The ammonia recovery device also includes an electrolyte storage tank, a nitrate wastewater storage tank, an ammonia absorption liquid storage tank, and a constant flow pump; Wherein, the liquid outlet of the electrolyte storage tank is connected to the liquid inlet of the anode chamber through the constant flow pump; the liquid outlet of the nitrate wastewater storage tank is connected to the anode chamber through the constant flow pump The liquid inlet port of the cathode chamber is connected; the liquid outlet part of the ammonia absorption liquid storage tank is connected with the liquid inlet port of the ammonia recovery chamber through the constant flow pump; The liquid inlet part of the electrolyte storage tank is connected with the liquid outlet of the anode chamber; the liquid inlet part of the nitrate wastewater storage tank is connected with the liquid outlet of the cathode chamber; the ammonia absorption liquid The liquid inlet part of the storage tank is communicated with the liquid outlet port of the ammonia recovery chamber. 2. The ammonia recovery device according to claim 1, wherein the counter electrode is a shape-stable anode, and the shape-stable anode includes lead oxide, iridium oxide, ruthenium oxide, and boron-doped diamond film electrodes. one of the 3. Ammonia recovery device according to claim 1, characterized in that, the cathode chamber is provided with a reference electrode; the reference electrode comprises one of silver silver chloride, saturated calomel and a standard hydrogen electrode . 4. Ammonia recovery device according to claim 1, characterized in that, said materials with electrochemical reduction of nitrate activity include ilmenite, cobalt phosphide, nanometer zero-valent iron, tricobalt tetroxide, nanometer zerovalent copper and titanium dioxide one or more of them. 5. The ammonia recovery device according to claim 1, characterized in that, an anolyte is stored in the electrolyte storage tank, and the anolyte comprises sodium sulfate solution. 6. Ammonia recovery device according to claim 1, is characterized in that, nitrate wastewater is stored in the nitrate wastewater storage tank, and the concentration range of nitrate in the nitrate wastewater is 500-50000 mg N/L . 7. The ammonia recovery device according to claim 1, wherein the ammonia absorption liquid is stored in the ammonia absorption liquid storage tank, and the ammonia absorption liquid comprises one of sulfuric acid solution, hydrochloric acid solution and carbonic acid solution . 8. The ammonia recovery device according to claim 1, wherein the liquid inlet and the liquid outlet of the anode chamber are oppositely arranged, and the height of the liquid inlet of the anode chamber is lower than the liquid outlet; The liquid inlet of the cathode chamber is opposite to the liquid outlet, and the height of the liquid inlet of the cathode chamber is lower than the liquid outlet; The liquid inlet and the liquid outlet of the ammonia recovery chamber are oppositely arranged, and the height of the liquid inlet of the ammonia recovery chamber is lower than the liquid outlet. 9. A method for ammonia recovery, characterized in that the ammonia recovery device as claimed in any one of claims 1-8 is used to recover ammonia from nitrate wastewater.

Images