CN111816902A - A capacitive microbial desalination battery device and method applied to chemical tail water treatment - Google Patents

Abstract

The invention discloses a capacitive microbial desalination cell device and method applied to chemical tail water treatment, and belongs to the technical field of water resource treatment. The cell device comprises an anode chamber, a desalting chamber and a cathode chamber which are respectively separated by an anion-cation exchange membrane and a cation-exchange membrane; the anode adopts a carbon material, and the cathode adopts a hollow carbon fiber-carbon film capacitor electrode formed by a hollow carbon fiber-carbon film capacitor layer, a titanium substrate, a waterproof layer and a catalytic layer which are sequentially arranged; the anode and the cathode are connected by an external circuit. The desalting method includes the steps of circulating chemical tail water inside the anode chamber, serial connecting the anode chamber and desalting chamber of the cell unit after certain residence time, and circulating the water treated in the anode chamber to the desalting chamber for desalting and/or COD. The invention can integrally and efficiently remove organic matters and salt in the chemical tail water, efficiently recover the salt, has stable electrode structure and long service life, and can be widely applied to the treatment of various chemical tail water.

Description

A capacitive microbial desalination battery device applied to chemical tail water treatment and the same method

technical field

The invention belongs to the field of water resources treatment, and in particular relates to a microbial desalination battery device and method equipped with a hollow carbon fiber-carbon membrane capacitor electrode, which is applied to the treatment of chemical tail water.

Background technique

Chemical tail water refers to the effluent wastewater that has been treated by the centralized sewage plant in the chemical park and meets the discharge standard of urban sewage Grade B or the discharge standard of local chemical enterprises. The residual salt is an important reason for inhibiting its recycling and resource utilization. At present, due to the high cost of tail water treatment, the recycled water in my country is mainly used in low-end recycling sections such as cooling cycles. Therefore, the ability to effectively remove a part of the salt in water at low cost and low energy consumption has practical research and application significance, which is also in line with the current situation. The sustainable concept of water saving advocated by the state. Traditional desalination methods are mainly divided into three categories: thermal separation, membrane separation, and electrochemical separation, such as multi-stage flash distillation, multi-effect distillation, electrodialysis, reverse osmosis and other processes have been widely used in the market. However, These desalination technologies all require additional energy input, and most of them are expensive to consume and operate, and may cause secondary pollution.

Microbial Desalination Cell (MDC) is a device that converts biomass energy into electricity and performs desalination simultaneously. It is based on microbial fuel cells, and anion and cation exchange membranes are added between the anode chamber and the cathode chamber to form an intermediate desalination chamber. The brine in the intermediate desalination chamber is desalinated without any external pressure and electrical energy; at the same time, the MDC anode The wastewater from the chamber is purified and electricity is generated. It can complete the desalination without any additional energy input, and can also complete the removal of organic matter in water in an integrated manner without causing secondary pollution.

In fact, chemical tail water still contains a certain amount of valuable salt that can be used for recycling. In addition, the microbial capacitive desalination battery (MCDC) is greatly limited by the service life of the capacitor electrode. The water quality conditions of the chemical tailwater are complex, and the electrode is easily affected by the fluctuation of the pH, temperature, and conductivity of the wastewater. Adsorption pollution on the surface of the electrode material, as well as the erosion corrosion of the electrode surface by the shear force of the wastewater containing suspended particles. Therefore, it is difficult for the conventional tablet preparation method to ensure the adhesion of the capacitor material on the conductive substrate, which is easy to cause the capacitor material to fall off, and it is difficult to effectively deal with the changing and complex industrial wastewater quality.

Based on this, it is necessary to configure a special capacitor electrode for the microbial desalination battery, which can improve the adhesion strength of the capacitor material and the stability of the electrode structure as a whole, so as to meet the desalination needs of various types of wastewater, and run for a long time to recover valuable salt. At the same time, optimizing the water intake method so that it can remove organic matter and salt in the same system will have a wide range of applications and market prospects.

SUMMARY OF THE INVENTION

1. The problem to be solved

Aiming at the problems that the existing microbial desalination battery is difficult to recover the value-added salt existing in the chemical tail water treatment process and the service life of the cathode electrode is short, the present invention is a hollow carbon fiber-carbon membrane capacitor cathode for use in the chemical tail water treatment. Microbial desalination battery device and method, by using hollow carbon fiber-carbon membrane capacitively coupled traditional platinum carbon coating catalytic cathode as cathode, effectively collect high value-added ions, realize the recovery of economic value salt in tail water, and at the same time, its structure can effectively improve the cathode's performance. service life.

Another object of the present invention is to simultaneously remove COD from chemical tail water and efficiently remove salt therein through the operation method of the above-mentioned microbial desalination battery device.

2. Technical solutions

In order to solve the above problems, the technical scheme adopted in the present invention is as follows:

A capacitive microbial desalination battery device applied to the treatment of chemical tail water, comprising an anode chamber, a desalination chamber and a cathode chamber, the anode chamber and the desalination chamber are separated by an anion exchange membrane, and the cathode chamber and the desalination chamber are separated by an anion exchange membrane. The chambers are separated by a cation exchange membrane; the anode of the battery device adopts a carbon material to load microorganisms and transfer electrons, and the cathode of the battery device adopts a hollow carbon fiber-carbon membrane capacitor electrode, and the hollow carbon fiber-carbon membrane capacitor electrode Carbon fiber-carbon film capacitor layer, titanium base layer, waterproof layer and catalytic layer; the anode and the cathode are connected by an external circuit equipped with a resistor. The anode is loaded with acclimated electricity-producing microorganisms, which can generate stable voltage while treating organic matter in water. It is equipped with a hollow carbon fiber-carbon membrane capacitor electrode as a cathode. Collects high value-added metal ions separated from tail water, and has the advantages of high capacitance and long life compared with traditional capacitive electrodes; the assembled cathode catalyzes the reduction reaction of oxygen molecules in the air as electron acceptors through the platinum carbon catalytic layer , the electrons are removed from the waterproof layer composed of PTFE to complete the electron transfer. At the same time, the movement of the electrons in the circuit in the battery forms an electric field, so that the wastewater in the demineralization chamber moves in a directional motion through the membrane separation to complete the demineralization, and the cations after passing through the membrane are adsorbed to the cathode. In the capacitor layer of , the device is applied to the advanced treatment of chemical tail water, which can recover the salt adsorbed by the cathode while realizing desalination.

Preferably, the hollow carbon fiber-carbon membrane capacitor layer structure is formed by covering a carbon membrane layer formed of carbonized microspheres on a titanium dioxide nanotube array embedded with hollow carbon fibers. The formation of titanium dioxide nanoarrays strengthens the bonding force between the capacitor layer and the titanium matrix, effectively improving the capacitor life; in addition, the carbon fibers are uniformly distributed on the titanium matrix in the presence of nickel in the precursor, and the formed hollow structure can be extremely It greatly increases the capacitance of the capacitor layer, adsorbs more renewable ions, and prolongs the regeneration period of the electrode.

Preferably, the area of the hollow carbon fiber-carbon membrane capacitor electrode is 1/2-3/4 of the cross-sectional area of the cathode chamber, so that the transmitted electrons can be unloaded into the cathode chamber in the waterproof layer. Electrical efficiency, and achieve higher salt removal rate and adsorption rate.

Preferably, the anode carbon material of the battery device includes carbon felt, carbon brush or activated carbon particles and the like. It is similar to the traditional microbial fuel cell, and its main function is to attach and enrich the electricity-producing microorganisms, and accept and transmit the electrons transferred from the extracellular electrons of the electricity-producing microorganisms.

Preferably, the anion exchange membrane and the cation exchange membrane of the microbial desalination battery device are heterogeneous electrodialysis ion exchange membranes, preferably with a thickness of 0.5-1.0 mm, independent permeability of not less than 90%, and burst strength greater than 0.3 Mpa.

Preferably, in the battery device, a resistance is connected in series between the cathode and anode, and the resistance value is 10-1500Ω.

Preferably, the preparation method of the hollow carbon fiber-carbon membrane capacitor electrode comprises using a titanium-based titanium dioxide nanotube array as a conductive matrix (current collector), using a mixed solution of glucose and nickel acetate as a precursor, and vacuum-induced, anaerobic pyrolysis In the step of obtaining an integrated hollow carbon fiber-carbon membrane capacitor layer with an embedded structure with hydrophilic modification, the temperature in the anoxic pyrolysis step is 800-850°C. The temperature in the anaerobic pyrolysis step is controlled at 800-850 °C to promote the transformation of TiO ₂ to titania structure, improve the current collection efficiency of the capacitor electrode, enhance the electronic conduction of the system, and promote the ion enrichment and ion enrichment of the MDC-capacitor system. release process.

Preferably, the specific preparation steps of the hollow carbon fiber-carbon membrane capacitor electrode are as follows:

Preparation of S1 precursor: prepare a certain concentration of glucose (C ₆ H ₁₂ O ₆ ) aqueous solution at room temperature, weigh a certain mass of nickel acetate (here all refer to tetrahydrate nickel acetate Ni(CH ₃ COO) ₂ ·4H ₂ O) solid , added to the aqueous glucose solution, stirred and dissolved to obtain the precursor;

S2 Place the titanium-based titanium dioxide nanotube array (current collector) in a two-necked or multi-necked flask with a stopper, make sure that the pure titanium side is facing down (that is, the nozzle of the titanium dioxide nanotube array is facing up), one side of the flask is connected to a vacuum pump, and the other port is connected Constant pressure dropping funnel with stopper, the funnel is filled with precursor; vacuum to a certain degree of vacuum, then open the constant pressure dropping funnel, drop the precursor into the two-necked bottle, until the liquid level is higher than the level of the current collector, close the funnel With the vacuum pump, slowly release the air pressure in the bottle to atmospheric pressure;

S3 take out the current collector treated in step S2 and place it on the water platform, make sure that the pure titanium side faces down, drop the precursor on the upper surface and spread it evenly to form a thin film, after aging at room temperature and in the air, it is pre-heated in a vacuum resistance box. Thermal decomposition, take out for use; this step is repeated many times to obtain the desired film thickness;

S4 placing the electrode after vacuum drying in step S3 in a muffle furnace, pyrolyzing in air, and then placing it in a nitrogen protection furnace for high-temperature carbonization and oxygen-free pyrolysis, and taking out to obtain a capacitor electrode with a formed hydrophobic capacitor layer;

S5, the capacitor electrode obtained in step S4 is placed in a nitric acid solution for constant temperature heating and acidification, and washed with deionized water until neutral, to obtain a capacitor electrode of a hydrophilic capacitor layer;

S6, on the titanium base layer on one side of the capacitor layer obtained in step S5, the waterproof layer is brushed three times with PTFE and nafion solution, and then the Pt-C catalyst is evenly coated on the side of the waterproof layer to obtain a hollow carbon fiber-carbon membrane capacitor electrode.

Preferably, in the step S1, the glucose concentration is 80-120 g/L, and the nickel acetate concentration is 10-40 g/L.

Preferably, the degree of vacuum in the step S2 is 0.01-0.03 MPa.

Preferably, in the step S3, the aging time is 12-24h, the vacuum heating temperature is 55-65°C, and the heating time is 12h.

Preferably, in the step S4, the heating/cooling rate of the muffle furnace in the air pyrolysis process is 1°C/min, and the holding time at 200-250°C is 2h; in the anaerobic pyrolysis process, the heating/cooling rate of the nitrogen protection furnace is 1°C/min , at 800-850 ℃ for 1h.

Preferably, in the step S5, the concentration of nitric acid is 4.5-5.5mol/L, the constant temperature heating temperature is 50-55°C, and the heating time is 18-24h.

Preferably, in the step S6, the PTFE is a PTFE solution with a mass fraction of 60%, and the nafion solution is coated with a 500 μL Nafion solution with a mass fraction of 5% per 5 mg of the Pt-C catalyst according to the coating amount of the Pt-C catalyst. -C catalyst coating amount is 0.2-0.6 mg/cm ² .

Preferably, the addition amount of the dropwise precursor in the step S3 is ≤ 0.03 μL; and/or the thickness of the titanium matrix in the titanium-based titanium dioxide nanotube array in the step S2 is ≤ 0.02 mm, so as to reduce the internal resistance of the system and achieve higher salt removal rate.

The present invention also provides a capacitive microbial desalination method applied to the treatment of chemical tail water. By using the above battery device, the chemical tail water is firstly circulated inside the anode chamber, and after a specific residence time, the anode of the battery device is recirculated. The chamber and the desalination chamber are connected in series, so that the water treated by the anode chamber enters the desalination chamber and circulates in the desalination chamber and the anode chamber to remove salt and/or COD;

Or firstly, the nutrient solution is used for internal circulation inside the anode chamber, and after a specific residence time, the chemical tail water is passed into the desalination chamber for circulating treatment and desalination, and the salt in the tail water is recovered at the same time;

Or firstly, the nutrient solution is used for internal circulation inside the anode chamber, and after a specific residence time, the chemical tail water is passed into the desalination chamber, and the desalination chamber is connected in series with the anode chamber, so that the chemical tail water is circulated in the desalination chamber and the anode chamber. Desalination and/or COD;

Or firstly, the nutrient solution is used for internal circulation inside the anode chamber, and after a certain residence time, the chemical tailwater is passed into the desalination chamber connected in series with the capacitor desalination reactor, so that the chemical tailwater is circulated in the desalination chamber and the capacitor desalination reactor. Internal circulation treatment to remove salt.

The COD remaining in the chemical tail water provides a carbon source for the anode electricity-generating microorganisms to complete the electricity-generating process. The electricity-generating microorganisms perform extracellular electron transfer and transfer electrons to the carbon material anode. The cycle of the anode chamber is also to start the entire system. After the chemical tail water enters the desalination chamber, the desalination can begin; after the anode cycle is stable, the tail water enters the desalination chamber, and when the anode generates current and forms an electric field, the ions in the tail water migrate through the membrane to complete the desalination process; this On the one hand, the cathode acts as the electron acceptor of the anode to complete the reduction process and electron transfer, so that the entire internal circulation system has an electric field; Compared with the traditional MDC, the invention combines the functions of the anode chamber and the desalination chamber in series for the first time to form an integrated treatment device, and increases the recovery function of high value-added metal ions, and is suitable for chemical industry containing certain residual organics. Treatment of tail water. However, the operation mode of the MDC system in the prior art is that the desalination chamber is subjected to sequencing batch or continuous flow desalination treatment. The anode and the desalination chamber work independently and do not have contact. The anode only generates energy by oxidatively degrading the carbon source. , to promote the operation of the whole system. Although the types of substrates in the anode chamber are constantly changing, it still does not substantially change the treatment method of MDC. It is directly applied to chemical tail water with complex composition.

Preferably, the water inflow mode of the desalination chamber in the battery device includes cyclic sequencing batch or continuous flow. When the cyclic sequencing batch water inlet mode is adopted, a separate recovery chamber is provided, the circulating flow rate is 0.5-5mL/min, and the residence time is 2-120h ; The influent flow rate of continuous flow is 0.2-1mL/min.

In the present invention, the demineralization chamber and the anode chamber can be connected in series for the removal of organics and salts from the same type of tail water in the battery device. This method can only be performed in a cyclic sequencing batch mode, and the circulating flow rate is 0.5-2 mL/min.

Preferably, the COD concentration of the chemical tail water entering the anode chamber of the battery device is 200-600 mg/L.

Preferably, the concentration of chemical tail water salt entering the anode chamber of the battery device is 10-25 g/L.

3. Beneficial effects

Compared with the prior art, the beneficial effects of the present invention are:

(1) Compared with the traditional MDC, the microbial desalination battery device of the present invention fully absorbs the principle of capacitance desalination, and takes into account the characteristics and treatment needs of chemical tail water, and is equipped with a new type of hollow carbon fiber-carbon membrane with high service life. Capacitive electrode has significant advantages: it can recover high value-added salt, and realize synchronous treatment of chemical tail water without adding energy, and has a wide range of applications;

(2) The novel hollow carbon fiber-carbon film capacitor electrode in the present invention enters the inside of the titania nanotube through the vacuum-induced precursor, and in the process of anaerobic pyrolysis, the divalent nickel is reduced while catalyzing the graphitization of the amorphous carbon, and It forms a solid titanium-nickel alloy with titanium atoms, and grows in-situ to obtain hollow carbon fibers embedded in titanium dioxide nanotubes. Through the "bridge" of the hollow carbon fibers, the carbonized microspheres formed on the surface are fixed on the titanium dioxide nanotube array On the surface, a stable and uniform carbon film layer is formed. At the same time, the anaerobic pyrolysis temperature is controlled at 800-850 ° C to promote the transformation of the TiO ₂ super titania structure, improve the current collection efficiency of the capacitor electrode, enhance the electronic conduction of the system, and promote The ion enrichment and release process of the MDC-capacitor system solves the shortcomings of weak force between the capacitor material and the conductive matrix of the conventional capacitor electrode, is not resistant to hydraulic shock, and is easy to fall off. Materials, the electrical layer formed on the surface of the material due to electrostatic action has limited capacitance, but the charge and discharge speed is fast, which meets the adsorption requirements of free ions in water) and pseudocapacitance (capacitive structure formed by metal oxides, due to the existence of metal oxides) , the capacitance of the capacitor layer is large) characteristics, which can ensure electron transfer while adsorbing ions, making the whole more suitable for chemical tailwater treatment with more complex components;

(3) In the present invention, the area of the cathode hollow carbon fiber-carbon membrane capacitor electrode is controlled to be 1/2-3/4 of the cross-sectional area of the cathode chamber, so that the transmitted electrons can be discharged into the cathode chamber in the waterproof layer, and the electron transfer is not affected at the same time. , improve the power generation efficiency, and achieve a higher salt removal rate and adsorption rate;

(4) In the present invention, by controlling the amount of the precursor added dropwise in step S3 of the electrode preparation process and regulating the thickness of the titanium substrate in step S2, the internal resistance of the system is reduced, and a higher salt removal rate can be achieved;

(5) The capacitive microbial desalination method of the present invention applied to the treatment of chemical tail water adopts the aforementioned battery device, and firstly, the chemical tail water is internally circulated in the anode chamber, and after a specific residence time, the anode of the battery device is recirculated. The desalination chamber and the desalination chamber are connected in series, so that the water treated by the anode chamber enters the desalination chamber, and the desalination and/or COD are cyclically processed in the desalination chamber and the anode chamber. For the first time, the functions of the anode chamber and the desalination chamber are combined in series to form an integrated The treatment device and treatment method are provided, and the recovery function of high value-added metal ions is added, and it is suitable for the treatment of chemical tail water containing certain residual organic matter.

Description of drawings

1 is a schematic structural diagram of a microbial desalination battery device of the present invention;

The marks in the figure are as follows: 1. Anode chamber; 2. Desalination chamber; 3. Cathode chamber; 4. Anode material; 5. Anode electricity-generating microorganism; 6. Anolyte; 7. Anion exchange membrane; 9. Hollow carbon fiber-carbon film capacitor electrode (9.1, capacitor layer; 9.2, titanium base layer; 9.3, waterproof layer; 9.4, catalytic layer); 10, external circuit;

Figure 2 is a schematic diagram of the preparation process and structure of the hollow carbon fiber-carbon film capacitor electrode capacitor layer;

Fig. 3 is the SEM image (a) of the hollow carbon fiber-carbon membrane capacitor electrode and the SEM image of the 45° top view (b);

Fig. 4 is the effect figure of embodiment 1 operation desalination and recovery salt concentration;

Fig. 5 is embodiment 3 running desalination and COD removal effect diagram;

Fig. 6 is the influence of different cathode area and cathode chamber cross-sectional area ratio on salt removal rate in embodiment 7;

Fig. 7 is the influence of different titanium substrate thickness and precursor dosage on cathode system internal resistance and on salt removal rate in Example 8;

Figure 8 is a comparison of titanium oxide formed after high temperature anaerobic pyrolysis reduction at 850°C and 650°C in Example 9;

FIG. 9 shows the internal resistance of the cathode system obtained by high temperature anaerobic pyrolysis reduction at different temperatures in Example 9 and the effect on the salt removal rate.

Detailed ways

It should be noted that when an element is referred to as being "mounted" to another element, it can be directly on the other element or the two elements can be directly integrated; when an element is referred to as being "connected" to another element, it can be It is directly connected to another element or possibly two elements are directly integrated. At the same time, terms such as "up", "down", "left", "right", "middle", etc. quoted in this specification are only for the convenience of description and clarity, and are not used to limit the scope of implementation. The change or adjustment of the relative relationship shall also be regarded as the scope of the present invention without substantially changing the technical content.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs; as used herein, the term "and/or" includes one or more of the associated listed Any and all combinations of items.

If the specific conditions are not indicated in the examples, it is carried out according to the conventional conditions or the conditions suggested by the manufacturer. The materials, reagents or instruments used without the manufacturer's indication are conventional products that can be purchased from the market. The experimental methods used are conventional methods unless otherwise specified.

As used herein, the term "about" is used to provide flexibility and imprecision associated with a given term, measure or value. The degree of flexibility of a particular variable can be readily determined by one skilled in the art.

As used herein, "adjacent" means that two structures or elements are in proximity. In particular, elements identified as "adjacent" may be contiguous or connected. Such elements may also be close or proximate to each other without necessarily touching each other. In some cases, the precise degree of approximation may depend on the particular context.

Concentrations, amounts, and other numerical data may be presented herein in range format. It is to be understood that such range formats are used for convenience and brevity only, and are to be flexibly construed to include not only the values expressly recited as the limits of the range, but also all individual values or subranges subsumed within the stated range, As if each numerical value and sub-range were expressly stated. For example, a numerical range of about 1 to about 4.5 should be construed to include not only the expressly recited limit of 1 to about 4.5, but also individual numbers (such as 2, 3, 4) and subranges (such as 1 to 3, 2) to 4, etc.). The same principle applies to ranges reciting only one numerical value, such as "less than about 4.5," which should be construed to include all of the aforementioned values and ranges. Furthermore, this interpretation should apply regardless of the breadth of the scope or features described.

Any steps recited in any method or process claims may be performed in any order and are not limited to the order presented in the claims. A method+function or step+function limitation is employed only if all of the following are present in a particular claim limitation: a) an explicit recitation of "means for" or "for... ..."; b) explicitly state the corresponding function. The structures, materials, or acts supporting the method+function are expressly recited in the description herein. Accordingly, the scope of the invention should be determined only by the appended claims and their legal equivalents, rather than by the description and examples given herein.

Example 1

The microbial desalination battery device of the present invention is used to process the salt in the chemical tail water of pesticide production and recover the salt, including the following steps:

Step 1. Preparation of hollow carbon fiber-carbon membrane capacitor electrodes

Step 1: Prepare 100 mL of 120 g/L glucose aqueous solution at room temperature, weigh 4 g of nickel acetate solid, add it into the glucose aqueous solution, stir and dissolve to obtain the precursor.

Step 2: Put the titanium-based titanium dioxide nanotube array (5cm×5cm×0.5mm, the thickness of the titanium substrate is 0.02mm) in a two-necked flask with a stopper, with the pure titanium side facing down, one side of the flask is connected to a vacuum pump, and the other port is connected to a A constant pressure dropping funnel is plugged, and the funnel is filled with precursors. Vacuum to 0.03MPa, then open the constant pressure dropping funnel, drop the precursor into the two-necked bottle until the liquid level is higher than the level of the current collector (the amount of the precursor is 0.03 μL), close the funnel and the vacuum pump, and slowly release the air pressure in the bottle to atmospheric pressure.

Step 3: Take out the current collector and place it on the water platform, with the pure titanium side facing down, drop 1mL of the precursor on the upper surface and spread it to form a thin film, age at room temperature and air for 24 hours, and place it in a vacuum resistance box at 65°C for 12 hours , take out the spare. This step is repeated 5 times.

Step 4: Put the vacuum-dried electrode in a muffle furnace, set the heating/cooling rate 1°C/min, pyrolyze it in the air at 250°C for 2 hours, then place it in a nitrogen protection furnace, set the heating/cooling rate 1°C/min , after carbonization and oxygen-free pyrolysis reduction at 850°C for 1 h, the temperature was lowered to room temperature, and the formed hydrophobic capacitor electrode was taken out.

The fifth step: the electrode is placed in a 5.5mol/L nitric acid solution, heated and acidified at a constant temperature of 55°C for 24h, washed with deionized water until neutral, and a hydrophilic capacitor electrode is obtained.

Step 6: Waterproof the titanium base layer side with 60% PTFE and 5% Nafion solution to form a waterproof layer, and evenly coat 0.35mg/cm ² Pt-C catalyst on the waterproof layer side, then The capacitor electrode was trimmed to 3/4 of the cross-sectional area of the cathode compartment.

Step 2. Assembly of the microbial desalination battery

Soak the anode carbon brush in the acclimated electricity-generating compound bacteria solution for more than 12 hours, then place the carbon brush in the anode chamber, and separate the anode chamber and the demineralization chamber with an anion exchange membrane with a thickness of 0.5 mm; The prepared hollow carbon fiber-carbon membrane capacitor electrode is placed in the cathode, the capacitor layer is placed in the demineralization chamber, the catalytic layer is in the air, and the cathode chamber and the demineralization chamber are separated by a 0.5mm cation exchange membrane, and the iron hoop flange is used to separate the cathode chamber and the demineralization chamber. Tie tightly to prevent water leakage and air entry. Connect the cathode and anode through wires and connect them in series with a resistor with a resistance value of 1000Ω.

Step 3. Operation of the microbial desalination battery

First, the general domestic sewage with a COD of 550 mg/L was circulated in the anode chamber as the anode nutrient solution, and the circulating flow rate was 1 mL/min. Then the chemical tail water with a salt concentration of 25 g/L to be treated was passed into the demineralizing chamber, and the circulating flow rate was It is 3.0mL/min, and the salt is collected through the cathode during the cycle, and the residence time in the demineralization chamber is 48h (one cycle). After 48h treatment, as shown in Figure 4 (120 cycles in total), the highest salt removal rate in chemical tail water can reach 82%, the effluent desalination rate is 184.0mg/h, and the concentration of concentrated liquid salt recovered by the cathode (regenerated brine concentration) is 697.23mg/L.

Example 2

Using the microbial desalination battery of the present invention to process pharmaceutical intermediates to produce salt in chemical tail water and recover the salt includes the following steps:

Step 1, preparing hollow carbon fiber-carbon membrane capacitor electrodes, which is the same as in Example 1;

Step 2. Assembly of the microbial desalination battery

The anode carbon felt was soaked in the acclimated electricity-generating compound bacteria solution for more than 12 hours, and then the carbon felt was placed in the anode chamber, and the anode chamber and the demineralization chamber were separated by an anion exchange membrane with a thickness of 0.25 mm; The prepared hollow carbon fiber-carbon membrane capacitor electrode is placed in the cathode, the capacitor layer is placed in the demineralization chamber, the catalytic layer is in the air, and the cathode chamber and the demineralization chamber are separated by a 0.25mm cation exchange membrane, and the iron hoop flange is used to separate the cathode chamber and the demineralization chamber. Tie tightly to prevent water leakage and air entry. Connect the cathode and anode through wires and connect them in series with a resistor with a resistance value of 800Ω.

Step 3. Operation of the microbial desalination battery

First, the food processing wastewater with a COD of 480 mg/L was circulated in the anode chamber as the anode nutrient solution, and the circulation flow rate was 0.8 mL/min. The flow rate was 2.5 mL/min, the salt was collected through the cathode during the cycle, and the residence time in the demineralization chamber was 72 h (one cycle). After 72 hours of treatment, the highest salt removal rate in chemical tail water can reach 58%, the effluent desalination rate is 144.0 mg/h, and the concentration of concentrated liquid salt recovered by the cathode is 537.16 mg/L.

Example 3

The use of the microbial desalination battery of the present invention to treat the residual organic pollutants and salinity of the pesticide chemical tail water in an integrated manner includes the following steps:

Step 1. Preparation of hollow carbon fiber-carbon membrane capacitor electrodes

The first step: prepare 100 mL of 100 g/L glucose aqueous solution at room temperature, weigh 2 g of nickel acetate solid, add it into the glucose aqueous solution, stir and dissolve to obtain the precursor.

Step 2: Put the titanium-based titanium dioxide nanotube array (5cm×5cm×0.5mm, the thickness of the titanium substrate is 0.02mm) in a two-necked flask with a stopper, with the pure titanium side facing down, one side of the flask is connected to a vacuum pump, and the other port is connected to a A constant pressure dropping funnel is plugged, and the funnel is filled with precursors. Vacuum to 0.01MPa, then open the constant pressure dropping funnel, drop the precursor into the two-necked bottle until the liquid level is higher than the level of the current collector (the amount of the precursor is 0.03 μL), close the funnel and the vacuum pump, and slowly release the air pressure in the bottle to atmospheric pressure.

Step 3: Take out the current collector and place it on the water platform, with the pure titanium side facing down, drop 0.5mL of the precursor on the upper surface and spread it into a thin film, age it at room temperature and air for 24 hours, and place it in a 60°C vacuum resistance box 12h, take it out for use. This step is repeated 4 times.

Step 4: Put the vacuum-dried electrode in a muffle furnace, set the heating/cooling speed to 1°C/min, pyrolyze it in air at 200°C for 2 hours, and then place it in a nitrogen protection furnace, set the heating/cooling speed to 1°C/min , after carbonization and oxygen-free pyrolysis reduction at 800°C for 1 h, the temperature was lowered to room temperature, and the formed hydrophobic capacitor electrode was taken out.

Step 5: The electrode is placed in a 5mol/L nitric acid solution, heated and acidified at a constant temperature of 55°C for 24h, washed with deionized water until neutral, and a hydrophilic capacitor electrode is obtained.

Step 6: Waterproof the titanium base layer with 60% PTFE and 5% nafion solution to form a waterproof layer, and evenly coat 0.30mg/cm ² Pt-C catalyst on the waterproof layer side, then The capacitor electrode was trimmed to 3/4 of the cross-sectional area of the cathode compartment.

Step 2. Assembly of the microbial desalination battery

The anode carbon felt was soaked in the acclimated electricity-generating compound bacteria solution for more than 12 hours, and then the carbon brush was placed in the anode chamber, and the anode chamber and the demineralization chamber were separated by an anion exchange membrane with a thickness of 0.5 mm; The prepared hollow carbon fiber-carbon membrane capacitor electrode is placed in the cathode, the capacitor layer is placed in the demineralization chamber, the catalytic layer is in the air, and the cathode chamber and the demineralization chamber are separated by a 0.5mm cation exchange membrane, and the iron hoop flange is used to separate the cathode chamber and the demineralization chamber. Tie tightly to prevent water leakage and air entry. Connect the cathode and anode through wires and connect them in series with a resistor with a resistance value of 800Ω.

Step 3. Operation of the microbial desalination battery

First, the chemical tail water with a COD concentration of 350 mg/L and a salt concentration of 20 g/L was circulated in the anode chamber for more than 36 hours, and the circulation flow rate was 1 mL/min. Container buffer flow, set the overall circulation flow rate to 1.5mL/min, and stay for a total of 72h (one cycle). As shown in Figure 5, the salt removal rate of the treated chemical tail water can reach up to 71%, and the COD removal rate is 59%.

Example 4

Using the microbial desalination battery integrated treatment resin of the present invention to process chemical tail water includes the following steps:

Step 1, preparing the hollow carbon fiber-carbon membrane capacitor electrode, which is the same as the preparation process in Example 2;

Step 2. Assembly of the microbial desalination battery

The anode carbon felt was soaked in the acclimated electricity-generating compound bacteria solution for more than 12 hours, and then the carbon brush was placed in the anode chamber, and the anode chamber and the demineralization chamber were separated by an anion exchange membrane with a thickness of 1.0 mm; The prepared hollow carbon fiber-carbon membrane capacitor electrode is placed in the cathode, the capacitor layer is placed in the demineralization chamber, the catalytic layer is in the air, and the cathode chamber and the demineralization chamber are separated by a 1.0mm cation exchange membrane, and the iron hoop flange is used to separate the cathode chamber and the demineralization chamber. Tie tightly to prevent water leakage and air entry. Connect the cathode and anode through a wire and connect a resistor with a resistance value of 500Ω in series.

Step 3. Operation of the microbial desalination battery

First, the resin processing chemical tail water with a COD concentration of 350 mg/L and a salt concentration of 23 g/L was used as the anode nutrient solution to circulate in the anode chamber for more than 42 hours, and the circulation flow rate was 1 mL/min, and then the demineralization chamber and the anode chamber were connected in series. , set the collection container buffer flow in the middle, set the overall circulation flow rate to 2.0mL/min, and stay for a total of 84h (one cycle). The salt removal rate of the treated chemical tail water is up to 73%, and the COD removal rate is 42%.

Example 5

The use of the microbial desalination battery of the present invention and the capacitor desalination technology to treat pesticide chemical tail water includes the following steps

Step 1. Preparation of hollow carbon fiber-carbon membrane capacitor electrodes

The first step: prepare 100 mL of 100 g/L glucose aqueous solution at room temperature, weigh 3 g of nickel acetate solid, add it into the glucose aqueous solution, stir and dissolve to obtain the precursor.

Step 2: Put the titanium-based titanium dioxide nanotube array (5cm×5cm×0.5mm, the thickness of the titanium substrate is 0.02mm) in a two-necked flask with a stopper, with the pure titanium side facing down, one side of the flask is connected to a vacuum pump, and the other port is connected to a A constant pressure dropping funnel is plugged, and the funnel is filled with precursors. Vacuum to 0.01MPa, then open the constant pressure dropping funnel, drop the precursor into the two-necked bottle until the liquid level is higher than the level of the current collector (the amount of the precursor is 0.03 μL), close the funnel and the vacuum pump, and slowly release the air pressure in the bottle to atmospheric pressure.

Step 3: Take out the current collector and place it on the water platform, with the pure titanium side facing down, drop 0.5mL of the precursor on the upper surface and spread it into a thin film, age it at room temperature and air for 18h, and place it in a 65℃ vacuum resistance box 12h, take it out for use. This step is repeated 4 times.

Step 4: Put the vacuum-dried electrode in a muffle furnace, set the heating/cooling speed to 1°C/min, pyrolyze it in air at 200°C for 2 hours, and then place it in a nitrogen protection furnace, set the heating/cooling speed to 1°C/min , after carbonization and oxygen-free pyrolysis reduction at 850°C for 1 h, the temperature was lowered to room temperature, and the formed hydrophobic capacitor electrode was taken out.

The fifth step: the electrode is placed in a 5mol/L nitric acid solution, heated and acidified at a constant temperature of 60°C for 24h, washed with deionized water until neutral, and a hydrophilic capacitor electrode is obtained.

Step 6: Waterproof the titanium base layer with 60% PTFE and 5% nafion solution to form a waterproof layer, and evenly coat 0.30mg/cm ² Pt-C catalyst on the waterproof layer side, then The capacitor electrode was trimmed to 3/4 of the cross-sectional area of the cathode compartment.

Step 2. Assembly of the microbial desalination battery and connection with the capacitive desalination reactor

The anode carbon felt was soaked in the acclimated electricity-generating compound bacteria solution for more than 12 hours, and then the carbon brush was placed in the anode chamber, and the anode chamber and the demineralization chamber were separated by an anion exchange membrane with a thickness of 0.5 mm; The prepared hollow carbon fiber-carbon membrane capacitor electrode is placed in the cathode, the capacitor layer is placed in the demineralization chamber, the catalytic layer is in the air, and the cathode chamber and the demineralization chamber are separated by a 0.5mm cation exchange membrane, and the iron hoop flange is used to separate the cathode chamber and the demineralization chamber. Tie tightly to prevent water leakage and air entry. Connect the cathode and anode to both sides of the capacitive desalination adsorption electrode through wires. The capacitor desalination electrode is also made of hollow carbon fiber-carbon film capacitor, and the electrode spacing is 2mm.

Step 3. Operation of Microbial Desalination Battery and Capacitive Desalination Combined System

First, the domestic wastewater with a COD of 480 mg/L was circulated in the anode chamber as the anode nutrient solution, and the circulating flow rate was 0.8 mL/min. Then the chemical tail water with a salt concentration of 25 g/L to be treated was passed into the demineralization chamber, and the The demineralization chamber is connected with the capacitive demineralization reactor (CDI). The specific conditions of the capacitive demineralization reactor are that the electrode area is 2cm×1cm, the constant voltage is 20V, and the flow mode in the reactor is cross-flow flow; the total circulating flow rate is 2.5 mL/min, the salt was collected through the cathode during the cycle with a total residence time of 60 h (one cycle). After 60 hours of treatment, the salt removal rate in the chemical tail water can reach 78%, and the concentration of concentrated liquid salt recovered by the cathode is 317.16 mg/L.

Example 6

The microbial desalination battery of the present invention is used in conjunction with the capacitor desalination technology to process pharmaceutical intermediates to produce chemical tail water, including the following steps

Step 1, preparing hollow carbon fiber-carbon membrane capacitor electrodes, which is the same as step 1 in Example 5;

Step 2, the assembly of the microbial desalination battery and the connection with the capacitor desalination reactor are the same as the second step in Example 5;

Step 3. Operation of Microbial Desalination Battery and Capacitive Desalination Combined System

First, the domestic wastewater with a COD of 500 mg/L was circulated in the anode chamber as the anode nutrient solution, and the circulating flow rate was 0.8 mL/min. Then the chemical tail water with a salt concentration of 20 g/L to be treated was passed into the demineralization chamber, and the The desalination chamber is connected with the capacitor desalination reactor, and the specific conditions of the capacitor desalination reactor are the same as in Example 5; the total circulating flow rate is 3.0 mL/min, and the salt is collected through the cathode during the circulation process, and the total residence time is 48h (one cycle ). After 48 hours of treatment, the salt removal rate in the chemical tail water can reach 71%, and the concentration of concentrated liquid salt recovered by the cathode is 236.68 mg/L.

Example 7

The cathode of the traditional microbial desalination battery is directly covered on the cathode chamber, but in the present invention, since the cathode of the capacitive microbial desalination battery is loaded with a titanium-based capacitive layer, it will hinder the electron transfer of the cathode. Therefore, by appropriately reducing the size of the cathode, the electrons can be The waterproof layer is unloaded into the cathode chamber. However, the size of the cathode will also limit the operating efficiency of the entire microbial desalination battery. If the area is too small, it will not only affect the desalination effect, but also the adsorption effect of the capacitor layer. Therefore, other conditions in this example are the same as those in Example 1. The difference is It is to use cathodes with different ratios of electrode area to cathode chamber cross-sectional area, so as to explore the optimal composite cathode area to complete the electron transfer process.

As shown in Figure 6, when the cathode area is 3/4 of the cross-sectional area of the cathode chamber, the transmitted electrons can be discharged into the cathode chamber in the waterproof layer, and the electricity generation efficiency is the highest without affecting the electron transfer, and the highest demineralization can be achieved. rate (77.03%) and adsorption rate.

Example 8

During the construction of the present invention, it is found that if the capacitive electrode is simply combined with the microbial desalination battery, the internal impedance of the microbial desalination battery will increase, resulting in excessive impedance of the entire system and low desalination efficiency, which greatly affects the operation of the entire reactor. Effect. Based on this, in order to reduce the internal impedance of the system, the thickness of the titanium substrate and the amount of the capacitor layer precursor were optimized. Other conditions in this example are the same as those in Example 1, the difference is that titanium sheets with thicknesses of 0.01mm, 0.02mm, 0.03mm, and 0.05mm are used for optimization, and the amount of the precursor dropped in the third step of the electrode preparation process is optimized. Take 0.01 μL/cm ² , 0.02 μL/cm ² , 0.03 μL/cm ² , and 0.05 μL/cm ² for optimization.

As shown in Figure 7, the thickness of the titanium substrate used in the cathode is ≤ 0.02 mm, the amount of the precursor is ≤ 0.03 μL, the internal resistance of the system is low, and a high salt removal rate can be achieved.

Example 9

The traditional TiO ₂ nanotube arrays used in capacitive electrodes, as current collectors, are not as conductive as pure Ti and Ti _n O _2n-1 (titanium oxide) materials in the process of capacitive adsorption. However, due to the applied voltage of the capacitive adsorption technique, the effect on the _TiO2 nanotube array layer is low. However, in the system of microbial desalination battery, due to the limited ability of microorganisms to generate electricity, the requirements for the conductivity of the current collector material are higher during the adsorption process, because it is necessary to convert _TiO2 nanotubes into better conductivity as much as possible. of titanium oxide material. On this basis, other conditions in this example are the same as those in Example 1, the difference is that the temperature of the fourth step of the electrode preparation process for high-temperature oxygen-free thermal reduction is optimized, and 600°C, 650°C, 700°C, and 750°C are selected respectively. , 800 ℃, 850 ℃ for anaerobic reduction experiments, in which the XRD of the material obtained by high temperature anaerobic thermal reduction (high temperature anaerobic pyrolysis) at 650 ℃ and 850 ℃ is shown in Figure 8, it can be seen that at 850 ℃ The peak intensity of titanium oxide (Ti ₅ O ₉ ) in the material obtained by high temperature oxygen-free thermal reduction is more obvious, and the capacitor electrode reduced at 850 °C has better desalination performance, indicating that the increase of titanium oxide caused by the increase of temperature The electron transfer is promoted and the performance of the current collector is optimized, so the preparation method in the present invention adopts a high temperature oxygen-free thermal reduction at 800-850 ° C to promote the transformation of TiO ₂ to a titanium oxide structure and improve the current collection efficiency of the capacitor electrode, Enhance the electronic conduction of the system and promote the ion enrichment and release process of the MDC-capacitor system.

In addition, the application experiment shown in Figure 9 shows that the material reduced above 800 °C has better adsorption capacity for salt.

The preferred embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the above-mentioned specific embodiments, and the devices and structures that are not described in detail should be understood to be implemented in ordinary ways in the art; any person skilled in the art, without departing from the present invention Within the scope of the technical solution of the invention, many possible changes and modifications can be made to the technical solution of the present invention by using the methods and technical contents disclosed above, or modified into equivalent embodiments with equivalent changes, which does not affect the essence of the present invention. . Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solutions of the present invention still fall within the protection scope of the technical solutions of the present invention.

Claims (10)

1. A capacitive microbial desalination cell device applied to chemical engineering tail water treatment is characterized by comprising an anode chamber, a desalination chamber and a cathode chamber, wherein the anode chamber and the desalination chamber are separated by an anion exchange membrane, and the cathode chamber and the desalination chamber are separated by a cation exchange membrane; the anode of the battery device adopts a carbon material to load microorganisms and transfer electrons, and the cathode of the battery device adopts a hollow carbon fiber-carbon film capacitor electrode which comprises a hollow carbon fiber-carbon film capacitor layer, a titanium-based layer, a waterproof layer and a catalyst layer which are sequentially arranged; the anode and the cathode are connected by an external circuit with a resistor.

2. The capacitive microbial desalination cell device applied to chemical tail water treatment as claimed in claim 1, wherein the hollow carbon fiber-carbon film capacitive layer structure is formed by covering a carbon film layer formed by carbonized microspheres on a titanium dioxide nanotube array embedded with hollow carbon fibers.

3. The capacitive microbial desalination cell device applied to chemical tail water treatment as claimed in claim 1, wherein the area of the hollow carbon fiber-carbon membrane capacitor electrode is 1/2-3/4 of the cross section of the cathode chamber.

4. The capacitive microbial desalination cell device applied to chemical tail water treatment as claimed in claim 2, wherein the anode carbon material of the cell device comprises carbon felt, carbon brush or activated carbon particles;

and/or the anion exchange membrane and the cation exchange membrane of the battery device are heterogeneous electrodialysis ion exchange membranes, the thickness is 0.5-1.0mm, the independent transmittance is not less than 90%, and the burst strength is more than 0.3 Mpa;

and/or a resistor is connected in series between the cathode and the anode in the battery device, and the resistance value is 10-1500 omega.

5. The capacitive microbial desalination cell device applied to chemical tail water treatment as claimed in claim 2, wherein the preparation method of the hollow carbon fiber-carbon film capacitive electrode comprises the steps of taking a titanium-based titanium dioxide nanotube array as a conductive substrate, taking a mixed solution of glucose and nickel acetate as a precursor, and performing vacuum induction, anaerobic pyrolysis and hydrophilic modification to obtain the integrated hollow carbon fiber-carbon film capacitive layer with the embedded structure, wherein the temperature in the anaerobic pyrolysis step is 800-.

6. The capacitive microbial desalination cell device applied to chemical tail water treatment as claimed in claim 5, wherein the specific preparation steps of the hollow carbon fiber-carbon membrane capacitive electrode comprise:

preparation of S1 precursor: preparing a glucose aqueous solution with a certain concentration at room temperature, weighing a certain mass of nickel acetate solid, adding the nickel acetate solid into the glucose aqueous solution, and stirring and dissolving to obtain a precursor;

s2, placing the titanium-based titanium dioxide nanotube array in a container, and enabling the pure titanium surface to face downwards and the pipe orifice of the titanium dioxide nanotube array to face upwards; vacuumizing to a certain vacuum degree, then dripping the precursor into the container until the liquid level is higher than the horizontal plane of the titanium-based titanium dioxide nanotube array, stopping vacuumizing, and slowly releasing the air pressure in the container to atmospheric pressure;

s3, taking out the titanium-based titanium dioxide nanotube array processed in the step S2, placing the titanium-based titanium dioxide nanotube array on a horizontal table board, enabling one surface of pure titanium to face downwards, dropwise adding the precursor on the upper surface of the titanium-based titanium dioxide nanotube array, uniformly smearing the precursor to form a film, aging the film in air at room temperature, preheating and decomposing the film through a vacuum resistance box, and taking out the film for later use; this step is repeated several times to obtain the desired film thickness;

s4, placing the electrode dried in vacuum in the step S3 in a muffle furnace, pyrolyzing the electrode in air, placing the electrode in a nitrogen protective furnace for high-temperature carbonization and oxygen-free pyrolysis, and taking out the electrode to obtain the capacitor electrode with the formed hydrophobic capacitor layer;

s5, placing the capacitance electrode obtained in the step S4 in a nitric acid solution, heating and acidifying at a constant temperature, and washing with deionized water until the capacitance electrode is neutral to obtain a capacitance electrode of a hydrophilic capacitance layer;

s6, brushing a waterproof layer on the titanium base layer on the side of the capacitor layer obtained in the step S5 by adopting PTFE and nafion solution, and then uniformly coating Pt-C catalyst on the side of the waterproof layer to obtain the hollow carbon fiber-carbon film capacitor electrode.

7. The capacitive microbial desalination cell device applied to chemical tail water treatment as claimed in claim 6, wherein the glucose concentration in step S1 is 80-120g/L, and the nickel acetate concentration is 10-40 g/L;

and/or the vacuum degree in the step S2 is 0.01-0.03 MPa;

and/or the aging time in the step S3 is 12-24h, the vacuum heating temperature is 55-65 ℃, and the heating time is 12 h;

and/or the muffle furnace temperature rising/reducing speed of the air pyrolysis process in the step S4 is 1 ℃/min, and the heat preservation time at 200 ℃ and 250 ℃ is 2 h; in the oxygen-free pyrolysis process, the temperature rising/reducing speed of the nitrogen protection furnace is 1 ℃/min, and the temperature is kept for 1h at 850 ℃ with 800-;

and/or in the step S5, the concentration of nitric acid is 4.5-5.5mol/L, the constant-temperature heating temperature is 50-55 ℃, and the heating time is 18-24 h;

and/or the PTFE in the step S6 is a PTFE solution with a mass fraction of 60%, the Nafion solution is coated with 500 mu L of Nafion solution with a mass fraction of 5% per 5mg of Pt-C catalyst according to the coating amount of the Pt-C catalyst, and the coating amount of the Pt-C catalyst is 0.2-0.6mg/cm²；

And/or the adding amount of the dropwise added precursor in the step S3 is less than or equal to 0.03 mu L;

and/or the thickness of the titanium matrix in the titanium-based titanium dioxide nanotube array in the step S2 is less than or equal to 0.02 mm.

8. A capacitive microbial desalination method applied to chemical tail water treatment is characterized in that by adopting the cell device of any one of claims 1 to 7, chemical tail water is internally circulated in an anode chamber, after a certain retention time, the anode chamber and a desalination chamber of the cell device are connected in series, and water treated by the anode chamber enters the desalination chamber and is circularly treated with desalination and/or COD in the desalination chamber and the anode chamber;

or firstly, nutrient solution is adopted to carry out internal circulation in the anode chamber, after specific retention time, chemical tail water is introduced into a desalting chamber to carry out circular treatment for desalting, and meanwhile, the salt in the tail water is recovered;

or firstly, nutrient solution is adopted to carry out internal circulation in the anode chamber, after specific retention time, chemical tail water is introduced into the desalting chamber, and the desalting chamber is connected with the anode chamber in series, so that the chemical tail water is circularly treated in the desalting chamber and the anode chamber to remove salt and/or COD;

or firstly, nutrient solution is adopted to carry out internal circulation in the anode chamber, and after a certain retention time, the chemical tail water is introduced into a desalting chamber connected in series with the capacitance desalting reactor, so that the chemical tail water is circulated in the desalting chamber and the capacitance desalting reactor for desalting treatment.

9. The capacitive microbial desalination method applied to chemical tail water treatment of claim 8, wherein the water inlet mode of the desalination chamber in the battery device comprises a circulation sequential batch or continuous flow, when the circulation sequential batch water inlet mode is adopted, a separate recovery chamber is arranged, the circulation flow rate is 0.5-5mL/min, and the retention time is 2-120 h; the flow rate of water inflow by adopting continuous flow is 0.2-1 mL/min.

10. The capacitive microbial desalination method applied to chemical tail water treatment as claimed in claim 8, wherein the COD concentration of the chemical tail water entering the anode chamber of the cell device is 200-600 mg/L;

and/or the concentration of chemical tail water salt entering the anode chamber of the cell device is 10-25 g/L.

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