CN106745676A - A kind of ecological many negative electrode urine processing devices and method - Google Patents

Abstract

The invention discloses an ecological multi-cathode urine treatment device and method. The device includes a three-chamber reactor, a urine storage tank, an ammonia absorption tank and a hydrogen storage tank. A peel electrode is arranged in the anode chamber, and a sludge electrode is arranged in the cathode chamber. Two After the sludge electrodes are connected in parallel, they are connected to the peel electrodes. A photovoltaic panel connected in series with the sludge electrodes is installed on the branch of each sludge electrode; the side of the cathode chamber that is not connected with the anode chamber is covered with an air cathode, and all air cathodes are connected in parallel. Then connect with the peel electrode. The invention can not only efficiently remove COD in urine, but also recycle ammonia nitrogen, hydrogen and other resources, and the treatment method does not require additional energy input, no secondary pollution, and is a conceptual urine that is environmentally friendly and sustainable. Processing devices and methods.

Description

An ecological multi-cathode urine treatment device and method

technical field

The invention relates to the technical field of urine treatment reactor development and water treatment, in particular to an ecological multi-cathode urine treatment device and method.

Background technique

Environmental protection and energy shortage are two major problems facing the world today. my country is in and will be in the stage of rapid industrialization and urbanization for a long time. Its rough development and irregular construction of drainage system have made wastewater treatment a bottleneck in my country's environmental governance.

During conventional wastewater treatment, wastewater treatment plants invest a large amount of energy to remove and recover nutrients (nitrogen and phosphorus). Among them, nitrogen-containing compounds are removed by converting into inert nitrogen; while phosphorus is mostly released from the system in the form of phosphate and other precipitates. However, approximately 80% of nitrogen, 50% of phosphorus and 10% of COD in domestic sewage are derived from human urine, which only accounts for 1% of the total volume of domestic sewage. If organic matter (COD), nitrogen, phosphorus and other low-quality energy and resources in domestic sewage can be recycled, it can not only greatly reduce the waste water treatment load, reduce treatment costs, but also recover energy and resources, which is beneficial to environmental protection and sustainable energy development is of great significance

Microbial fuel cells (MFCs) and microbial electrolysis cells (MECs) are emerging bioelectrochemical technologies that can recover clean energy and resources while treating wastewater. This type of technology degrades organic matter or electrons through Exoelectrogen loaded on the surface of the anode, and transfers electrons to the anode through electron mediators or nanowires. Under the action, the cathode produces hydrogen gas. This type of technology has the characteristics of high pollution reduction efficiency, low energy consumption, no secondary pollution and clean energy recovery, which is in line with the concept of environmental friendliness and sustainable development.

Patent CN201110029516.5 provides a kind of urine that is diluted more than 10 times and treated by nitrifying microorganisms, and then nitrogen removal is realized under the action of microorganisms in the denitrification reactor. This method is an energy-consuming purification method, and the total amount of pollutants discharged into the sewage after a large amount of dilution increases and there is no resource recovery.

Patent CN201210128854.9 provides a magnetic organic composite nano denitrification material obtained by adding specially treated limonite under the action of an external magnetic field. This method only considers how to avoid the secondary pollution of ammonia nitrogen, and it is not very good recycling resources. In the existing urine wastewater treatment technology, there is no relatively mature technical solution.

Patent CN201210131068.4 discloses a combined system of membrane bioreactor and sewage treatment device. The system solves the problems of high electric field treatment cost, inhibition of microbial activity, and sludge treatment existing in the existing process of using an additional electric field to control membrane fouling. However, this system uses metal building materials such as titanium wire and stainless steel as electrode materials, which has disadvantages such as high cost and easy corrosion, and the cathode consumables required for this type of reactor increase the cost input.

Therefore, it is necessary to develop a device and method with low energy consumption, high efficiency, and recovery of resources such as ammonia nitrogen by using advanced bioelectrochemical technology.

Contents of the invention

The invention provides an ecological multi-cathode urine treatment device and method, which can not only efficiently remove COD in urine, but also recover resources such as ammonia nitrogen and hydrogen, and the treatment method does not require additional energy input and has no secondary pollution , is a conceptual urine treatment device and method in line with environmental friendliness and sustainable development.

An ecological multi-cathode urine treatment device includes a three-chamber reactor, a urine storage tank, an ammonia absorption tank and a hydrogen storage tank, the three-chamber reactor includes an anode chamber in the middle and cathode chambers on both sides of the anode chamber, and the anode The chamber and the two cathode chambers are separated by a cation exchange membrane, the anode chamber is provided with a urine inlet and outlet, and the gas outlet of the cathode chamber is sequentially connected to an ammonia absorption tank and a hydrogen storage tank;

A peel electrode is set in the anode chamber, a sludge electrode is set in the cathode chamber, two sludge electrodes are connected in parallel and connected in series with the peel electrode, and a photovoltaic panel connected in series with the sludge electrode is provided on the branch of each sludge electrode;

All sides of the cathode chamber that are not connected with the anode chamber are covered with air cathodes, and the inside of the air cathodes is loaded with anion exchange membranes to separate them from the solution, and all the air cathodes are connected in parallel with the peel electrodes in series.

All the air cathodes are connected in parallel with the sludge cathodes, that is, an anode is set in the device of the present invention, and all the cathodes are independent of each other and all connected in parallel, and then connected to the anode after being connected in parallel.

The carbonized peel anode and the sludge cathode are connected in series with photovoltaic panels through wires to provide additional voltage for the cathode to produce hydrogen.

The reactor of the present invention is followed by a left chamber, a middle chamber and a right chamber along the length direction, and the left chamber, the right chamber and the middle chamber are separated by a cationic membrane, and all air cathodes and sludge electrodes are connected in parallel by wires. Connected with the peel electrode at night without light, the anode electrogenic bacteria generate electrons and increase the concentration of NH ₄ ⁺ by degrading COD, oxygen receives electrons from the anode through the air cathode to generate OH ^- , OH ^- diffuses to the cathode chamber and NH ₄ ⁺ Reaction produces NH ₃ gas overflow, NH ₃ is recovered by dilute acid solution, and the urine is pretreated; the anode of the carbonized peel and the cathode of the activated sludge are connected by a wire and a photovoltaic panel is connected in series, under the condition of light during the day , The voltage generated by the photovoltaic panel is added to the voltage generated during the urine treatment, so that the urine is electrolyzed to hydrogen after the cathode chamber is processed, and the hydrogen is recovered through the hydrogen storage tank, and the urine after the preliminary pretreatment is strengthened. The method achieves the purpose of efficiently treating urine and recovering clean energy hydrogen and ammonia nitrogen resources on the basis of no additional energy consumption.

Preferably, all sides of the cathode chamber that are not connected to the anode chamber are covered with air cathodes, and an anion exchange membrane is loaded on the inside of each air cathode. Further preferably, the cathode chamber has 6 surfaces, and air cathodes are provided on the five surfaces not connected with the anode chamber.

Preferably, the peel electrode is prepared by the following method:

(1) Cut the discarded peel into shape, and air-dry it for 20-30 hours under natural conditions;

(2) Dry the cut and air-dried peel at 60-90°C for 0.5-2 hours in a nitrogen atmosphere;

(3) Under a nitrogen atmosphere, control the temperature at 800-1000° C., carbonize the fruit peel, and naturally cool to room temperature under a nitrogen atmosphere after carbonization, and set aside for later use.

Further preferably, it is prepared by the following method:

(1) Cut the discarded peel into shape, and air-dry it for 24 hours under natural conditions;

(2) After cutting and air-drying, dry the skin at 80°C for 1 hour under nitrogen atmosphere;

(3) Under a nitrogen atmosphere, control the temperature to 900° C., carbonize the fruit peel, and cool it down to room temperature naturally under a nitrogen atmosphere after the carbonization, and set aside.

Preferably, the discarded peels include watermelon peels, pomelo peels, straws, etc., as well as peels and agricultural wastes that may be used as anodes outside the above range. Further preferably, the anode of the peel is carbonized pomelo peel, which has a large amount of raw material, and is spongy after carbonization, has many pores, and has good electrical conductivity, which is conducive to microbial film formation and electron export.

Preferably, the sludge electrode is a carbonized sludge electrode, prepared by the following method:

(1) The sludge is mechanically crushed after being dried in an oven at 40-60°C for 1-3 hours;

(2) The crushed sludge passes through a 80-120 mesh screen to remove large particles in the sludge;

(3) mixing the filtered sludge with hydrogen peroxide hydrogen peroxide accounting for 5% to 20% of the sludge mass to prepare an initial electrode;

(4) The initial electrode is sintered in a nitrogen atmosphere, and the temperature is controlled at 800-1200° C. for 1-3 hours. After heating, it is naturally cooled to room temperature in a nitrogen atmosphere.

Further preferably, the sludge electrode is prepared by the following method:

(1) The sludge is mechanically crushed after being dried in an oven at 50°C for 2 hours;

(2) After crushing, the sludge is filtered with a 100-mesh screen to remove large particles in the sludge;

(3) mixing the filtered sludge with hydrogen peroxide to prepare an initial electrode;

(4) Sintering in a nitrogen atmosphere, the temperature is controlled at 1000° C. for 2 hours, and naturally cooled to room temperature in a nitrogen atmosphere after heating.

Preferably, the sludge includes excess sludge, municipal sludge, agricultural waste, etc., as well as sludge and feces that may be used as anodes outside the above range. It is further preferred to be the surplus sludge electrode of the sewage plant. The raw material is huge, and the sludge composition is complex. After carbonization, it has good electrical conductivity and catalytic performance, stable operation, and no secondary pollution.

Preferably in the present invention, the peel electrode and the sludge electrode used are original electrodes of the present invention. The peel electrode has a high specific surface area and good electrical conductivity, which can improve the performance of electricity production. At the same time, the heavy metals and active functional groups in the sludge electrode have catalytic effects To improve the reduction performance of the cathode, the fruit peel electrode and the sludge electrode are used together to achieve the purpose of treating urine wastewater with low energy consumption and high efficiency.

Preferably, the air cathode material is platinum-loaded carbon cloth, carbon paper or a self-prepared electrode. It is further preferably a self-prepared electrode, which is pressed by a waterproof breathable white film, a catalytic black film, and a stainless steel mesh. Compared with platinum-loaded carbon cloth or carbon paper, the production cost is low, and the three-dimensional structure can provide a large number of oxygen reduction interfaces, reducing Water loss through the cathode.

Preferably, the air cathode preparation method is as follows:

(1) Activated carbon, acetylene black and polytetrafluoroethylene (PTFE) are mixed according to the mass ratio of 3: (3 ~ 4): (3 ~ 4) and then pressed on the stainless steel net to form a film with a thickness of 0.2 ~ 0.3mm;

(2) Reduction method loads catalysts such as Ag on the film surface of step (1) gained;

(3) Sodium sulfate and PTFE are pressed on the electrode gained in step (2) after mixing by (3～4): (6～7) mass ratio;

(4) The anion exchange membrane is treated at 140° C. and 1780 kPa for 3 minutes, and directly hot-pressed onto the cathode prepared in step (3).

The catalyst is _Ag or the like, and the reduction method is as follows: in a 0.1M AgNO3 solution, a silver electrode is used as an anode, one side of the cathode obtained in step (1) is used as a cathode, and electrolytic reduction is performed at a voltage of 5-6V.

The application of the air cathode can solve the problem of increasing the processing cost of this technology due to the use of cathode consumables; however, the devices in the previous patents only use an air cathode on one side, making the cathode the speed-limiting step of the system. The device in the present invention adopts the parallel combination of bidirectional and multifaceted air cathodes, which solves the problem that it becomes the speed-limiting step of waste water treatment and energy recovery due to the limited area. The principle of the method is simple, but it is of great significance.

The volume ratio of the anode chamber and the cathode chamber (single) is 1:0.2˜1:2.

The cathode chamber has a gas outlet, and the gas outlet is sequentially connected to the ammonia absorption tank and the hydrogen storage tank. When the mixed gas passes through the ammonia absorption tank, the absorption liquid in the absorption tank absorbs the ammonia gas, and the hydrogen continues to enter the hydrogen storage tank for further processing. store.

The present invention also provides a method for treating urine using the ecological multi-cathode urine treatment device, comprising the following steps:

(1) The anode chamber is inoculated with bacterial solution, and after successful film formation, the urine for anaerobic fermentation at room temperature for 8 to 12 days (preferably 10 days) is continuously sent to the anode chamber, and the cathode chamber is filled with electrolyte;

(2) In the absence of light, anode electrogenic bacteria generate electrons by degrading COD and increase the concentration of NH ₄ ⁺ , oxygen receives electrons from the anode through the air cathode to generate OH ^- , and OH ^- diffuses to the cathode chamber to react with NH ₄ ⁺ Generate NH ₃ gas overflow, recover NH ₃ through dilute acid solution; the urine after preliminary treatment in the anode chamber is exported and temporarily stored;

(3) Start the photovoltaic panel under light conditions to provide a stable voltage, and the urine after the preliminary treatment in step (2) is continuously sent into the anode chamber again, and the anode electrogenic bacteria obtain electrons by degrading organic matter, and transfer the electrons to Sludge cathode, supply voltage, H ⁺ in the electrolyte in the cathode chamber obtains electrons and reduces to H ₂ , which is exported from the cathode chamber to the hydrogen storage tank;

(4) The urine thoroughly purified by the anode chamber is exported from the drain pipe, and part of it is used as the electrolyte of the cathode chamber.

In the present invention, the urine purified by the method of the present invention is directly used as the catholyte, and after the treatment, the urine used as the electrolyte in the cathode chamber is discharged from the drain pipe.

Preferably, the voltage provided by the photovoltaic cell panel is 0.7-1.0V.

Preferably, the reactor is started under normal temperature conditions (20-40° C.) after the photovoltaic cell panel is turned on.

Preferably, the bacteria solution is composed of organic wastewater with a COD concentration of 4000-6000 mg/L and the electrogenic bacteria solution in a volume ratio (3-5):1.

Further, the bacterial liquid is composed of organic wastewater with a COD concentration of 5000 mg/L and an electrogenic bacterial liquid at a volume ratio of 1:4.

The electrogenic bacteria used in the present invention are conventional electrogenic bacteria, such as Geobacteraceae species and Shewanella species etc.

Preferably, the urine inflow and outflow of the anode chamber is 0.1-0.5m ³ /(m ³ ·d), and considering the COD removal efficiency and removal effect, it is more preferably 0.3m ³ /(m ³ ·d).

Further preferably, the device start-up stage is added before step (1): M9 electrolyte is added to the cathode, and the bacteria solution is inoculated in the anode chamber. ) composition, turn on the photovoltaic panels, start the reactor at 30°C, and the start-up time is about 1 to 7 days;

In the start-up phase, the M9 electrolyte is used as the electrolyte of the cathode chamber, and the urine thoroughly purified by the method of the present invention is used as the electrolyte of the cathode chamber during normal operation.

After the device is running stably, the urine is continuously sent into the anode chamber at a flow rate of 0.3m ³ /(m ³ d) twice during the day and night, and the microorganisms on the anode electrode obtain sufficient carbon sources, and COD is effectively degraded; the cathode chamber Electrolyte (i.e. treated urine) is changed periodically based on pH. The anode electrode of the present invention adopts carbonized pericarp electrode, uses the pericarp in domestic garbage as raw material, and obtains an anode with high specific surface area, high conductivity, and high biocompatibility through a series of treatments; the cathode electrode adopts residual sludge from a sewage plant, and undergoes a series of treatments Get activated sludge cathode, turn waste into treasure.

The invention utilizes electroactive microorganisms loaded on the surface of the anode to degrade COD in organic wastewater to generate electrons. Under the condition of no light at night, the urine is continuously sent into the anode chamber, and the completely treated urine is sent into the cathode chamber as an electrolyte, and the anode produces electrons. Electrobacteria generate electrons by degrading COD and increase the concentration of NH ₄ ⁺ , oxygen receives electrons from the anode through the air cathode to generate OH ^- , OH ^- diffuses to the cathode chamber and reacts with NH ₄ ⁺ to generate NH ₃ gas overflows, and the urine is preliminarily predicted Treatment: Under daytime light conditions, the preliminary treated urine is continuously sent to the anode chamber again, the air cathode continues to function, and the electrons are exported through an external circuit to generate a voltage of 0.3-0.6V, and the photovoltaic panel provides an additional 0.7-1.0V under light conditions. V voltage, H ₂ is obtained from the urine completely treated in the electrolysis cathode chamber, and the alkalinity of the cathode chamber is further increased, more NH ₃ gas overflows, NH ₃ is recovered by washing with dilute acid solution, H ₂ is recovered through the hydrogen storage tank, and urine liquid is completely processed. Fully processed urine can be used as catholyte.

The present invention combines MFCs and MECs, two emerging bioelectrochemical technologies, and utilizes principles such as ion diffusion to obtain clean energy and valuable resources while treating urine, which is in line with the concept of environmental friendliness and sustainable development; more meaningfully, The whole set of equipment has a low investment cost, and it turns solid waste such as fruit peels and excess sludge into treasures, achieving the effect of waste pollution control, which is quite innovative.

The invention adopts solid wastes on the electrode materials, and the anode material and the cathode material are respectively prepared from waste fruit peels and surplus sludge, so as to achieve the purpose of pollution control by waste. In terms of processing technology, the present invention couples MECs and MFCs systems to a three-chamber reactor to realize integration, and recovers resource NH ₃ and clean energy H ₂ while treating urine.

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

(1) The wall of the cathode chamber adopts an air cathode to realize the _O2 in the air as a direct electron acceptor, without the need for cathode consumables, which greatly reduces the cost input;

(2) A photovoltaic panel is connected in series between the anode of the carbonized peel and the cathode of the carbonized sludge, and under sunlight conditions, the urine is treated to obtain H ₂ at the same time;

(3) The anode material in the anode chamber and the cathode material in the cathode chamber are respectively made of carbonized fruit peel and excess sludge to reduce the load of waste disposal and solve environmental problems such as large amount of excess sludge and difficult disposal;

(4) The device is coupled with MECs and MFCs systems to efficiently treat COD in urine and recover ammonia nitrogen and H ₂ .

Description of drawings

Fig. 1 is a structural schematic diagram of the reactor of the present invention.

Fig. 2 is a schematic structural view of the cathode chamber of the present invention.

Fig. 3 is a schematic diagram of the connection between the electrodes of the present invention.

1-Hydrogen storage tank 2-Ammonia absorption tank 3-Cathode chamber

4-air cathode 5-sludge electrode 6-cation exchange membrane

7- Peel electrode 8- Photovoltaic panel 9- Anode chamber

10-Anode chamber outlet 11-Anode chamber inlet 12-Urine storage tank

13-anion exchange membrane 14-light source.

detailed description

As shown in Figure 1 and Figure 2, an ecological multi-cathode urine treatment device includes a three-chamber reactor, a urine storage tank 12, an ammonia absorption tank 2 and a hydrogen storage tank 1, and the three-chamber reactor is a cuboid reactor, and the interior is along the Its length direction is divided into three chambers by the cation exchange membrane 6, the middle chamber is an anode chamber 9, and both sides of the anode chamber are cathode chambers 3.

The anode chamber has a urine inlet 11 and a urine outlet 10, the urine inlet is connected to a urine storage tank 12, and the urine storage tank is used to store the original urine, and the cathode chambers on both sides have gas outlets, and the gas outlets are connected to ammonia in turn. Gas absorption tank 2 and hydrogen storage tank 1.

The anode chamber is provided with a peel electrode 7; the cathode chamber has an electrolyte inlet and a waste liquid outlet, and a sludge electrode 5 is arranged in the cathode chamber, and a circular air cathode 4 is respectively arranged on the five sides of the cathode chamber that are not connected with the anode chamber, and the air The outside of the cathode is in contact with the air, and the inside is loaded with an anion exchange membrane 13 to separate it from the liquid in the cathode chamber. The exploded view of the cathode chamber is shown in FIG. 2 .

The connection mode between the peel electrode and the sludge electrode and the air cathode is shown in Figure 3 (wherein Figure 1 is not drawn according to the actual connection mode for the sake of clarity of the accompanying drawings, and the connection mode is subject to Figure 3), two sewage After the mud electrode is connected in parallel, it is connected in series with the peel electrode, and a photovoltaic panel 8 is connected in series on the branch of each sludge electrode, and 10 air cathodes are connected in parallel with the sludge electrodes and then connected in series with the peel electrode, that is, the peel electrode is the anode. Two sludge electrodes and ten air cathodes are independent of each other and connected in series with peel electrodes to form a loop.

The light source 14 provides illumination for the photovoltaic panel, and the light source 14 may be natural light or equipment such as a lighting lamp.

Wherein, the peel electrode used is prepared by the following method:

(1) Cut the discarded peel into shape, and air-dry it for 20-30 hours under natural conditions;

(2) Dry the cut and air-dried peel at 60-90°C for 0.5-2 hours in a nitrogen atmosphere;

(3) Under a nitrogen atmosphere, control the temperature at 800-1000° C., carbonize the fruit peel, and naturally cool to room temperature under a nitrogen atmosphere after carbonization, and set aside for later use.

This embodiment can preferably be prepared by the following method:

(1) Cut the discarded peel into shape, and air-dry it for 24 hours under natural conditions;

(2) After cutting and air-drying, dry the skin at 80°C for 1 hour under nitrogen atmosphere;

(3) Under a nitrogen atmosphere, control the temperature to 900° C., carbonize the fruit peel, and cool it down to room temperature naturally under a nitrogen atmosphere after the carbonization, and set aside.

The sludge electrode is a carbonized sludge electrode prepared by the following method:

(1) The sludge is mechanically crushed after being dried in an oven at 40-60°C for 1-3 hours;

(2) The crushed sludge passes through a 80-120 mesh screen to remove large particles in the sludge;

(3) mixing the filtered sludge with hydrogen peroxide hydrogen peroxide accounting for 5% to 20% of the sludge mass to prepare an initial electrode;

(4) The initial electrode is sintered in a nitrogen atmosphere, and the temperature is controlled at 800-1200° C. for 1-3 hours. After heating, it is naturally cooled to room temperature in a nitrogen atmosphere.

In this embodiment, preferably, it is prepared by the following method:

(1) The sludge is mechanically crushed after being dried in an oven at 50°C for 2 hours;

(2) After crushing, the sludge is filtered with a 100-mesh screen to remove large particles in the sludge;

(3) mixing the filtered sludge with hydrogen peroxide to prepare an initial electrode;

(4) Sintering in a nitrogen atmosphere, the temperature is controlled at 1000° C. for 2 hours, and naturally cooled to room temperature in a nitrogen atmosphere after heating.

The air cathode preparation method is as follows:

(1) Activated carbon, acetylene black and polytetrafluoroethylene (PTFE) are mixed according to the mass ratio of 3: (3~4): (3~4) and then pressed on the stainless steel net to form a film with a thickness of 0.2~0.3mm;

(2) Reduction method loads catalysts such as Ag on the film surface of step (1) gained;

(3) Sodium sulfate and PTFE are pressed on the electrode gained in step (2) after mixing by (3～4): (6～7) mass ratio;

(4) The anion exchange membrane is treated at 140° C. and 1780 kPa for 3 minutes, and directly hot-pressed onto the cathode prepared in step (3).

The catalyst is _Ag or the like, and the reduction method is as follows: in a 0.1M AgNO3 solution, a silver electrode is used as an anode, one side of the cathode obtained in step (1) is used as a cathode, and electrolytic reduction is performed at a voltage of 5-6V.

The process and principle are as follows:

The film-hanging microorganisms in the anode chamber are electrogenic bacteria. Under the condition of no light at night, the urine is continuously sent to the anode chamber, and the completely treated urine is sent to the cathode chamber as an electrolyte. The anode electrogenic bacteria generate electrons and increase NH by degrading COD. ₄ ⁺ concentration, oxygen receives electrons from the anode through the air cathode to generate OH ^- , OH ^- diffuses to the cathode chamber and reacts with NH ₄ ⁺ to generate NH ₃ gas overflows through the absorption of alkene acid, and the urine is initially treated; under daylight conditions , the preliminary treatment of urine is sent to the anode chamber continuously, the air cathode continues to play a role, the electrons are exported through the external circuit to generate a voltage of 0.3-0.6V, and the photovoltaic panel provides an additional voltage of 0.7-1.0V under the condition of light, and the electrolysis cathode chamber is completely The treated urine obtains H ₂ , which further increases the alkalinity of the cathode chamber, and more NH ₃ gas overflows. The NH ₃ is washed and recovered by dilute acid solution, and the H ₂ is recovered through the hydrogen storage tank, and the urine is completely processed. Fully processed urine can be used as catholyte.

Example 1

The anode degradation chamber enters the urine with a COD concentration of 12000mg/L and an ammonia nitrogen content of 4500mg/L at a flow rate of 0.3m ³ /(m ³ ·d), and the cathode chamber enters the treated urine. According to the above method, the voltage was controlled to be 0.7V and operated stably for 5 days. Water samples were collected regularly to analyze the COD degradation, and hydrogen gas was collected to calculate the hydrogen production. A total of 5 batches were run in the same way.

Results: Wastewater COD effluent decreased to 450-600mg/L, ammonia nitrogen content decreased to 60-75mg/L, hydrogen production per liter of urine was 8.20L-9.56L, and more than 2g of NH ₄ ⁺ -N was recovered per L of urine.

Example 2

The anode degradation chamber enters the urine with a COD concentration of 11000mg/L and an ammonia nitrogen content of 5000mg/L at a flow rate of 0.3m ³ /(m ³ ·d), and the cathode chamber enters the treated urine. According to the above method, the voltage was controlled to be 1.0V and operated stably for 5 days. Water samples were collected regularly to analyze the COD degradation, and hydrogen gas was collected to calculate the hydrogen production. A total of 5 batches were run in the same way.

Results: Wastewater COD effluent decreased to 300-500mg/L, ammonia nitrogen content decreased to 45-55mg/L, hydrogen production per liter of domestic sewage treatment was 10.11L-10.46L, and more than 3g of NH ₄ ⁺ -N was recovered per L of urine.

The above is only a specific implementation case of the patent of the present invention, but the technical characteristics of the patent of the present invention are not limited thereto, and any changes or modifications made by those skilled in the relevant fields within the scope of the present invention are covered by the patent of the present invention. within the scope of the patent.

Claims (8)

1. An ecological multi-cathode urine treatment device comprises a three-chamber reactor, a urine storage tank, an ammonia absorption tank and a hydrogen storage tank, and the three-chamber reactor includes an anode chamber positioned in the middle and a cathode chamber positioned at both sides of the anode chamber , the anode chamber and the two cathode chambers are separated by a cation exchange membrane, the anode chamber is provided with a urine inlet and outlet, and the gas outlet of the cathode chamber is sequentially connected to an ammonia absorption tank and a hydrogen storage tank; it is characterized in that, A peel electrode is set in the anode chamber, a sludge electrode is set in the cathode chamber, two sludge electrodes are connected in parallel and connected in series with the peel electrode, and a photovoltaic panel connected in series with the sludge electrode is arranged on the branch of each sludge electrode; All sides of the cathode chamber that are not connected with the anode chamber are covered with air cathodes, and the inside of the air cathodes is loaded with anion exchange membranes to separate them from the solution, and all the air cathodes are connected in parallel with the peel electrodes in series. 2. according to the described ecological multi-cathode urine treatment device of claim 1, it is characterized in that, described pericarp electrode is prepared by following method: (1) Cut the discarded peel into shape, and air-dry it for 20-30 hours under natural conditions; (2) Dry the cut and air-dried peel at 60-90°C for 0.5-2 hours in a nitrogen atmosphere; (3) Under a nitrogen atmosphere, control the temperature at 800-1000° C., carbonize the fruit peel, and cool it down to room temperature naturally under a nitrogen atmosphere after the carbonization is completed, and set aside for later use. 3. according to the described ecological multi-cathode urine treatment device of claim 1, it is characterized in that, described sludge electrode is prepared by following method: (1) The sludge is mechanically crushed after being dried in an oven at 40-60°C for 1-3 hours; (2) The crushed sludge passes through a 80-120 mesh screen to remove large particles in the sludge; (3) mixing the filtered sludge with hydrogen peroxide to prepare an initial electrode; (4) The initial electrode is sintered in a nitrogen atmosphere, and the temperature is controlled at 800-1200° C. for 1-3 hours. After heating, it is naturally cooled to room temperature in a nitrogen atmosphere. 4. A method utilizing the ecological multi-cathode urine treatment device of claim 1 to process urine, characterized in that, comprising the steps of: (1) The anode chamber is inoculated with the bacterial solution, and after successful film formation, the urine that has been anaerobically fermented at room temperature for 8 to 12 days is continuously sent to the anode chamber, and the cathode chamber is filled with electrolyte; (2) In the absence of light, anode electrogenic bacteria generate electrons by degrading COD and increase the concentration of NH ₄ ⁺ , oxygen receives electrons from the anode through the air cathode to generate OH ^- , and OH ^- diffuses to the cathode chamber to react with NH ₄ ⁺ Generate NH ₃ gas overflow, recover NH ₃ through dilute acid solution; the urine after preliminary treatment in the anode chamber is exported and temporarily stored; (3) Start the photovoltaic panel under light conditions to provide a stable voltage, and the urine after the preliminary treatment in step (2) is continuously sent into the anode chamber again, and the anode electrogenic bacteria obtain electrons by degrading organic matter, and transfer the electrons to Sludge cathode, supply voltage, H ⁺ in the electrolyte in the cathode chamber obtains electrons and reduces to H ₂ , which is exported from the cathode chamber to the hydrogen storage tank; (4) The urine thoroughly purified by the anode chamber is exported from the drain pipe, and part of it is used as the electrolyte of the cathode chamber. 5. The method according to claim 4, characterized in that the voltage provided by the photovoltaic cell panel is 0.7-1.0V. 6. The method according to claim 4, characterized in that the rate of introducing and exporting the raw urine into and out of the anode chamber is both 0.1-0.5m ³ /(m ³ ·d). 7 . The method according to claim 4 , wherein the electrogenic bacteria solution is composed of the electrogenic bacteria solution and organic wastewater with a COD concentration of 4000-6000 mg/L at a volume ratio of 1: (3-5). 8. The method according to claim 4, characterized in that, between step (1), the device start-up stage is added: the cathode is added with M9 electrolyte, the anode chamber is inoculated with bacterial solution, the photovoltaic cell panel is turned on, and the reactor is started at 30°C , The start-up time is 1-7 days.