A continuous flow fuel cell module for removing ammonia nitrogen and organic matter from water

Abstract

The present invention discloses a continuous flow fuel cell module for removing ammonia nitrogen and organic matter from water, which includes a plurality of unit modules, each unit module includes a shell, the shell is filled with fuel and a hole-responsive catalyst, the water inlet and the water outlet of two adjacent unit modules are connected to each other to form a pipeline series structure; the cathode is a titanium dioxide nanotube mesh electrode modified with a single-element bismuth element, the anode is a light-responsive electrode composed of a single-sided conductive glass modified with tungsten trioxide and a polycrystalline silicon photocell, and the fuel contains ammonia nitrogen and organic pollutants. The present invention uses a polycrystalline silicon photocell to provide a self-driven voltage, thereby eliminating the need for an external voltage drive and containing no toxic byproducts. The highly modular device is conducive to maintenance, debugging, transformation and industrial promotion. The catalyst sodium bisulfite has a cost of only one-fifteenth of that of sodium hypochlorite, and is a low-cost treatment solution for ammonia nitrogen-containing organic wastewater with good treatment effect.

Description

Technical Field

[0001] The invention relates to a fuel cell for photoelectrocatalytically recovering chemical energy and simultaneously treating ammonia nitrogen and organic matter in wastewater, and in particular to a modular and continuous-flow photoelectrocatalytic reactor controlled by a computer. Background Art

[0002] Ammonia nitrogen is a common pollutant in wastewater. The concentration of ammonia nitrogen is related to the degree of eutrophication of water bodies. There is a contradiction in the commonly used activated sludge method for treating organic wastewater containing ammonia nitrogen, that is, the removal of ammonia nitrogen requires two steps, nitrification and denitrification, and their operating conditions are completely different, which increases the operating cost and has poor treatment efficiency. Photoelectrocatalysis is a new process for treating organic wastewater that has been popular in the scientific research community recently. Its advantages are low cost. The operating mechanism based on the advanced oxidation process makes it have a high mineralization rate for organic matter, high treatment efficiency, and can recycle the chemical energy in organic matter to generate additional electrons for power generation. However, like the activated sludge method, the general form of photoelectrocatalysis still has limited ability to degrade ammonia nitrogen. The reason is that the main goal of wastewater denitrification is to convert the valence of nitrogen into zero valence, that is, to remove it in the form of nitrogen gas, and ammonia nitrogen containing negative trivalent nitrogen and nitrate nitrogen containing positive pentavalent nitrogen are both water pollutants. However, the strong oxidizing free radicals produced by the photoelectrocatalytic method, such as hydroxyl and superoxide radicals, can easily oxidize ammonia nitrogen into nitrate nitrogen. This mechanism makes it difficult to completely remove ammonia nitrogen by the photoelectrocatalytic method.

[0003] Breakpoint chlorination is the most commonly used method for water plants to remove ammonia nitrogen from water, but the breakpoint chlorination method still has disadvantages. Sodium hypochlorite as an oxidant is expensive and the byproduct chloramines are biologically toxic. The principle of the breakpoint chlorination method is to use the appropriate redox potential of chloroxy free radicals to highly selectively oxidize ammonia nitrogen into nitrogen gas. Among the many free radicals, sulfoxyl free radicals have a similar redox potential to chloroxyl free radicals, so sulfoxyl free radicals also have the ability to oxidize ammonia nitrogen into nitrogen gas, and the reduction product of sulfoxyl free radicals is sulfate ion. Sulfate ion itself is non-toxic and is not defined as a pollutant. The solubility of various sulfates is lower than that of chloride salts. Therefore, the introduction of sulfate can also effectively reduce the hardness of water bodies.

[0004] The flue gas of thermal power plants is rich in sulfur dioxide. Sodium bicarbonate solution can be used to absorb sulfur dioxide waste gas to produce sodium bisulfite solution. Compared with sodium hypochlorite, the cost of sodium bisulfite is only one-fifteenth of that of sodium hypochlorite. Therefore, it is very economical to use the "waste" generated by thermal power plants - sodium bisulfite instead of sodium hypochlorite to treat ammonia nitrogen.

[0005] At present, there are a large number of related fuel cell solutions that use sunlight to remove pollutants from wastewater at home and abroad. For example, (CN103367759A, CN106299418A) proposed to combine photochemistry with wastewater treatment and apply it to the field of fuel cells, but no mature and scalable structural solution was given. Another example is (Nano Energy 2020, 67, 104237), which gives a feasible modular photochemical fuel cell structure for treating wastewater, but its system is completely sealed, without air bubbling, which has a greater impact on the reaction in the early stage of the degradation reaction; the light source is designed inside the reactor, resulting in the need for an external power supply for the system operation, and the solar energy is not fully utilized; the structural design is sealed, and the replacement process of the double-sided electrodes after installation is relatively complicated; the distance between the double-sided electrodes is too close, and an additional nylon mesh is required to separate the double-sided electrodes to prevent short circuits. The above reasons lead to its lack of prospects for large-scale application. This patent innovatively provides a highly modular continuous fuel cell solution for removing high-concentration ammonia nitrogen and organic matter in water. It does not require an external power supply and can treat sewage with only sufficient light and air. The excellent design structure allows the electrodes to be easily replaced according to the waste composition, and it has strong scalability. There is space between the electrode plates, and there is no need to use a partition to separate the electrodes on both sides. The number of modules can be increased or decreased according to the actual wastewater situation to achieve a balance between pollution removal performance and economic benefits, and it has prospects for large-scale application. Summary of the invention

[0006] The technical problem to be solved by the present invention is: to use sunlight and exhaust gas from power plants to construct a method with certain industrial potential for efficiently removing ammonia nitrogen and organic pollutants while generating electricity, which can maintain a high removal rate of ammonia nitrogen and organic pollutants under low-cost, green and secondary pollution-free operating conditions.

[0007] In order to solve the above technical problems, the present invention is implemented by the following technical solutions:

[0008] A continuous flow fuel cell module for removing ammonia nitrogen and organic matter in water comprises a plurality of unit modules, each unit module comprises a shell, the shell is provided with a water inlet, a water outlet and an aeration port, an anode and a cathode are arranged in the shell, and the shell is filled with fuel and a hole-responsive catalyst, the water inlets and the water outlets of two adjacent unit modules are interconnected to form a pipeline series structure, and the anodes and cathodes in all unit modules are connected to a circuit control system through wires; the cathode is a titanium dioxide nanotube mesh electrode modified with a single substance bismuth element, the anode is a light-responsive electrode composed of a single-sided conductive glass modified with tungsten trioxide and a polycrystalline silicon photocell to provide an initial voltage for the operation of the fuel cell module, the fuel contains ammonia nitrogen and organic pollutants, and the hole-responsive catalyst contains sodium bisulfite.

[0009] Preferably, the shell is made of quartz glass.

[0010] Preferably, the preparation method of the cathode is as follows: pre-cleaning the titanium mesh with acetone, ethanol and deionized water in sequence; preparing a mixed solution of hydrofluoric acid, nitric acid and deionized water, and immersing the pre-cleaned titanium mesh in the mixed solution to remove surface oxides; winding and fixing three titanium meshes after removing surface oxides with copper wire as anodes, and platinum electrodes as cathodes, with an electrode spacing of 30 mm, applying a DC voltage of 5 to 30 V, and oxidizing in an ethylene glycol solution containing 0.3% ammonium fluoride by mass and 2% deionized water by volume with constant temperature micro-stirring for 1 to 6 hours, taking out after oxidation and washing with deionized water, and heating at 5 The titanium dioxide nanotube mesh electrode can be prepared by annealing at 00°C for 2h; 0.01-0.05g of bismuth nitrate pentahydrate is ultrasonically dissolved in a deionized water solution containing 0.1-0.5g of sodium sulfate and 0.1-0.8g of disodium ethylenediaminetetraacetate, and the prepared titanium dioxide nanotube mesh electrode is used as a working electrode, a platinum electrode is used as a counter electrode, and a silver-silver chloride electrode is used as a reference electrode, and electrodeposition is performed for 5-30min under a voltage condition of -0.1-2V. After the electrodeposition is completed, the electrode is rinsed and dried to obtain the titanium dioxide nanotube mesh cathode modified with the elemental bismuth element.

[0011] Preferably, the preparation method of the anode is as follows: dissolving 0.1-1g of ammonium paratungstate hydrate in 93mL of deionized water; then, adding 2mL of hydrochloric acid and 4mL of hydrogen peroxide to the solution, stirring until it is completely dissolved and transparent; transferring the transparent solution to a polytetrafluoroethylene-lined autoclave, immersing a fluorine-doped tin oxide-coated glass substrate pre-cleaned with acetone, ethanol, and deionized water in the autoclave containing the above solution with the conductive surface facing downward, and performing a hydrothermal process at 160°C for 4h, followed by annealing at 500°C for 2h; connecting the prepared tungsten trioxide photoanode and the polycrystalline silicon solar cell panel with copper wire to obtain the light-responsive anode of the combination of the single-sided conductive glass modified with tungsten trioxide and the polycrystalline silicon photocell.

[0012] More preferably, the purity of the aqueous hydrochloric acid solution is 37% (volume percentage).

[0013] More preferably, the purity of the hydrogen peroxide aqueous solution is 30% (volume percentage).

[0014] More preferably, the purity of the hydrofluoric acid aqueous solution is 40% (volume percentage).

[0015] More preferably, the purity of the nitric acid aqueous solution is 68% (volume percentage).

[0016] More preferably, the purity of the other reagents is 99% (mass percentage).

[0017] More preferably, the polycrystalline silicon photovoltaic cell has a rated voltage of 2V and a rated current of 35mA.

[0018] Preferably, in the fuel, the concentration of ammonia nitrogen is 10-100 mg / L, and the concentration of organic pollutants is no more than 50 mg / L.

[0019] Preferably, the concentration of sodium bisulfite in the hole-responsive catalyst is no greater than 0.1M.

[0020] The present invention also provides an application of the above-mentioned continuous flow fuel cell module for removing ammonia nitrogen and organic matter from water: the battery module is irradiated with sunlight or a xenon lamp is used to simulate sunlight, and fuel and a hole-responsive catalyst (sodium bisulfite) are continuously pumped into the water inlet of the first unit module, and air is blown into the aeration port of each unit module. Under the irradiation of sunlight, the photoanode surface is driven to generate holes to oxidize sodium bisulfite to produce sulfoxide free radicals, and the sulfite free radicals in the sulfoxide free radicals are converted into persulfate free radicals through air aeration, thereby oxidizing ammonia nitrogen into nitrogen. The cathode receives electrons from the photoanode to reduce part of the over-oxidized ammonia nitrogen into nitrogen.

[0021] Preferably, in the mixture of the fuel and the hole-responsive catalyst, the concentration of the fuel measured by N element is 30 mg / L NH4 + , the concentration of sodium bisulfite is 0.1M.

[0022] Preferably, the xenon lamp has a wavelength of 390 to 770 nm and a light intensity of 0.1 to 15 W / cm 2 .

[0023] Preferably, the flow rate of the fuel and the hole-responsive catalyst is 0.001 to 0.1 L / min; the flow rate of the air is 0.1 to 10 L / min.

[0024] Preferably, the single operation time for treating ammonia nitrogen and organic pollutants in the fuel is 15 to 60 minutes.

[0025] The present invention provides a fuel cell for removing ammonia nitrogen and organic matter from water based on the concept of "using waste to treat waste". Its characteristics are: the operating conditions of the fuel cell include sunlight and continuous blowing of air, and the fuel cell is composed of several unit modules, which are connected to each other through wires and polyethylene pipes, so that the circuits of each unit module are operated in parallel and the water circuits are operated in series.

[0026] The present invention does not require a built-in light source or an external voltage, and can directly utilize natural light to produce a reaction; the modularization degree is high, and there is no need for tight sealing, and the electrodes can be replaced at any time; the photoanode can float on the water surface, and the cathode is fixed on the bottom of the water. The gap between the electrodes is large, and there is no need to use nylon membranes to isolate the electrodes to avoid short circuits; the air permeability is good, and air can be continuously blown in to maintain the smooth progress of the reaction; the liquid flow rate is accurately controlled by a water pump, and a single module can be operated; polymer material pipes such as polyethylene pipes can be used to connect the modules in series, and wires can be used to connect the circuits between the modules in parallel. According to actual needs, multiple separate modules can be combined into a system according to the above method to collaboratively remove high-concentration ammonia nitrogen and organic matter in water.

[0027] The light-responsive anode of the combination of the single-sided conductive glass modified with tungsten trioxide and the polycrystalline silicon photocell has excellent photoelectrochemical performance, can be self-driven without external voltage under sunlight, and can be used for the degradation of ammonia nitrogen and organic pollutants.

[0028] The titanium dioxide nanotube cathode modified with the single substance bismuth element in the present invention is mainly used to reduce the nitrite and nitrate generated in the process of degrading ammonia nitrogen into nitrogen gas.

[0029] The working principle of the present invention is: under the condition of sunlight, holes-electron pairs are generated on the surface of tungsten trioxide, and the holes oxidize sodium bisulfite in water to produce a large number of sulfite free radicals. The oxygen in the air is continuously introduced to oxidize the sulfite free radicals into persulfate free radicals. Both the sulfite free radicals and the persulfate free radicals can simultaneously oxidize ammonia nitrogen and organic matter, and the products are carbon dioxide, nitrogen, nitrite, and nitrate. The electrons generated on the surface of tungsten trioxide are quickly separated to the titanium dioxide nanotube mesh cathode modified with the elemental bismuth element through the polycrystalline silicon photocell, and the nitrite and nitrate are reduced to nitrogen. In the degradation process, the chemical energy of ammonia nitrogen and organic matter is recovered, and the operating current increases with the increase of pollutant concentration.

[0030] The fuel cell constructed by using the prepared single-sided conductive glass modified with tungsten trioxide and the light-responsive anode of the polycrystalline silicon photovoltaic cell and the titanium dioxide nanotube mesh cathode modified with the elemental bismuth element operates under the conditions of no external bias and continuous aeration and sunlight. The degradation and power generation capabilities are proved by experiments. 50mg / L rhodamine B and 50mg / L phenol are mixed in 0.1M sodium bisulfite catalyst and 100mg / L ammonia nitrogen solution respectively. After 1h of degradation, the removal rate of ammonia nitrogen reaches 93.5%, and the removal rates of rhodamine B and phenol reach 95.1% and 90.9% respectively. The short-circuit current during the degradation process is, the open-circuit voltage is, and the maximum power is. The experimental results prove that the performance of the fuel cell has reached the expected goal.

[0031] The beneficial effects of the present invention are: using sulfur dioxide in the flue gas of thermal power plants to treat ammonia nitrogen and organic wastewater, fully embodying the concept of "treating waste with waste". The degradation efficiency of organic matter is high, the operating conditions are simple and additional electricity can be generated. The degradation efficiency of ammonia nitrogen is no less than that of the breakpoint chlorination method, and the selectivity of ammonia nitrogen conversion into nitrogen is higher and the cost is lower. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A schematic diagram of a continuous flow fuel cell module provided by the present invention;

[0033] Figure 2 is a schematic diagram of a unit module;

[0034] Figure 3 is the X-ray diffraction pattern of tungsten trioxide photoanode;

[0035] Figure 4 This is the X-ray diffraction pattern of the titanium dioxide nanotube mesh cathode modified with single element bismuth;

[0036] Figure 5 This is a comparison chart of the impact of pollutant degradation on power generation performance;

[0037] Figure 6 This is the characteristic curve of electricity generation when degrading ammonia nitrogen and phenol;

[0038] Figure 7 The graphs of the concentrations of total nitrogen, ammonia nitrogen, nitrate nitrogen and nitrite nitrogen changing with time at different sodium bisulfite concentrations;

[0039] Figure 8 The figure is a bar chart comparing the removal rates of different types of organic pollutants. DETAILED DESCRIPTION

[0040] In order to make the present invention more clearly understood, preferred embodiments are described in detail below with reference to the accompanying drawings.

[0041] like Figure 1-2As shown, a continuous flow fuel cell module for removing ammonia nitrogen and organic matter from water provided by the present invention comprises a plurality of unit modules, each unit module comprises a shell 1, a water inlet 2, a water outlet 3 and an aeration port 4 are arranged on the shell 1 (a fixed aeration port can be provided, or the top of the shell is set as an open structure, and the entire open structure is an aeration port), an anode 5 and a cathode 6 are arranged in the shell 1, and the shell 1 is filled with fuel and a hole-responsive catalyst, the water inlet 2 and the water outlet 3 of two adjacent unit modules are interconnected to form a pipeline series structure, and the anode 5 and the cathode 6 in all unit modules are connected to the circuit control system 7 through a wire; the cathode 6 is a titanium dioxide nanotube mesh electrode modified with a single element of bismuth, the anode 5 is a light-responsive electrode composed of a single-sided conductive glass modified with tungsten trioxide and a polycrystalline silicon photocell to provide an initial voltage for the operation of the fuel cell module, the fuel contains ammonia nitrogen and organic pollutants, and the hole-responsive catalyst contains sodium bisulfite. The shell 1 is made of quartz glass.

[0042] The preparation method of the cathode 6 is as follows: pre-clean the titanium mesh with acetone, ethanol and deionized water in turn; prepare a mixed solution of hydrofluoric acid, nitric acid and deionized water in a volume ratio of 1:4:5, and immerse the pre-cleaned titanium mesh in the mixed solution to remove surface oxides; fix three treated titanium meshes with copper wire as anodes, and platinum electrodes as cathodes, with an electrode spacing of 30 mm, apply a DC voltage of 30 V, and oxidize in an ethylene glycol solution containing 0.3% ammonium fluoride by mass and 2% deionized water by volume at a constant temperature with micro-stirring for 6 hours, and take out the titanium mesh after oxidation. The titanium dioxide nanotube mesh electrode was prepared by washing with deionized water and annealing at 500°C for 2h. 0.1M bismuth nitrate pentahydrate was ultrasonically dissolved in a deionized water solution of 0.1M sodium sulfate and 0.05M disodium ethylenediaminetetraacetic acid, and the prepared titanium dioxide nanotube mesh electrode was used as a working electrode, a platinum electrode was used as a counter electrode, and a silver-silver chloride electrode was used as a reference electrode. The electrode was electroplated at a voltage of -0.2V for 30min. After the electrodeposition was completed, the electrode was rinsed and dried to obtain the titanium dioxide nanotube mesh cathode modified with the elemental bismuth element.

[0043] The preparation method of the anode 5 is as follows: dissolving ammonium paratungstate hydrate in deionized water; then, adding hydrochloric acid and hydrogen peroxide to the solution, stirring until it is completely dissolved and transparent; transferring the transparent solution to a polytetrafluoroethylene-lined autoclave, immersing a fluorine-doped tin oxide-coated glass substrate pre-cleaned with acetone, ethanol, and deionized water in the autoclave containing the above solution with the conductive surface facing downward, performing a hydrothermal process at 160° C. for 4 hours, and then annealing at 500° C. for 2 hours; connecting the prepared tungsten trioxide photoanode and the polycrystalline silicon solar cell panel with copper wire to obtain the light-responsive anode of the combination of the single-sided conductive glass modified with tungsten trioxide and the polycrystalline silicon photocell.

[0044] The concentration of ammonia nitrogen in the fuel is 10-100 mg / L, and the concentration of organic pollutants is not more than 50 mg / L. The concentration of sodium bisulfite in the hole-responsive catalyst is not more than 0.1M.

[0045] Example 1

[0046] The removal capacity of ammonia nitrogen in water was investigated. 30 mL of water contained an ammonia nitrogen concentration of 100 mg / L, a sodium bisulfite concentration of 0.1 M, an external bias voltage of 0, and the irradiance of the xenon lamp was adjusted to 1 standard sun by an illuminance meter. The anode was a light-responsive anode composed of a single-sided conductive glass modified with tungsten trioxide and a polycrystalline silicon photocell, and the illumination area was (3 cm × 3 cm). The cathode was a titanium dioxide nanotube mesh cathode modified with bismuth. The aeration rate was set to 1 L / min. The removal rate of ammonia nitrogen within 1 hour reached 93.5% (calculated as total nitrogen removal rate). Figure 7 As shown in (c), the remaining nitrogen in the water body mainly exists in the form of nitrate nitrogen, and no nitrite nitrogen was detected.

[0047] Example 2

[0048] The removal rates of ammonia nitrogen under different sodium bisulfite concentrations were compared. The ammonia nitrogen concentration in 30 mL of water was 100 mg / L, and the sodium bisulfite concentrations were 0 M, 0.05 M, and 0.1 M, respectively. The total electrolyte concentration was kept consistent by adding different amounts of sodium sulfate, and the external bias voltage was 0. The irradiance of the xenon lamp was adjusted to 1 standard sun by the illuminometer. The anode was a light-responsive anode composed of a single-sided conductive glass modified with tungsten trioxide and a polycrystalline silicon photocell, and the illumination area was (3 cm × 3 cm). The cathode was a titanium dioxide nanotube mesh cathode modified with bismuth. The aeration rate was set to 1 L / min. Figure 7 As shown, the removal rates of ammonia nitrogen within 1 hour reached 13.7%, 76.7% and 93.5% respectively (calculated based on total nitrogen removal rate).

[0049] Example 3

[0050] The removal effect of different concentrations on ammonia nitrogen was compared. 30mL of water contained ammonia nitrogen concentrations of 20mg / L, 40mg / L, 60mg / L, 80mg / L, and 100mg / L, respectively. The sodium bisulfite concentration was 0.1M, the external bias voltage was 0, and the irradiance of the xenon lamp was adjusted to 1 standard sun by the illuminometer. The anode was a light-responsive anode composed of a single-sided conductive glass modified with tungsten trioxide and a polycrystalline silicon photocell, and the illumination area was (3cm×3cm). The cathode was a titanium dioxide nanotube mesh cathode modified with elemental bismuth. The aeration rate was set to 1L / min. The removal rates of ammonia nitrogen within 1h reached 93.6%, 95.5%, 95.8%, 94.3%, and 93.5%, respectively (calculated as total nitrogen removal rate).

[0051] Example 4

[0052] The removal capacity of different organic pollutants in water was investigated. 30 mL of water contained 50 mg / L of rhodamine B and phenol, 0.1 M sodium bisulfite concentration, and 0 bias voltage. The irradiance of the xenon lamp was adjusted to 1 standard sun by an illuminance meter. The anode was a light-responsive anode composed of a single-sided conductive glass modified with tungsten trioxide and a polycrystalline silicon photocell, and the illumination area was (3 cm × 3 cm). The cathode was a titanium dioxide nanotube mesh cathode modified with bismuth. The aeration rate was set to 1 L / min. Figure 8 As shown, the removal rates of organic matter within 1 hour reached 95.1% and 90.9%, and the removal rates of total organic carbon (TOC) were 86.5% and 82.7%.

[0053] Example 5

[0054] The ability to remove ammonia nitrogen under high load conditions was investigated. 500mL of water contained an ammonia nitrogen concentration of 100mg / L, a sodium bisulfite concentration of 0.1M, an external bias of 0, and the irradiance of the xenon lamp was adjusted to 1 standard sun by an illuminometer. The anode was a light-responsive anode composed of a single-sided conductive glass modified with tungsten trioxide and a polycrystalline silicon photocell, and the illumination area was (3cm×3cm). The cathode was a titanium dioxide nanotube mesh cathode modified with elemental bismuth. The aeration rate was set to 10L / min. The removal rate of ammonia nitrogen within 1h reached 89.4% (calculated as total nitrogen removal rate).

[0055] Example 6

[0056] The ability to remove ammonia nitrogen and organic matter simultaneously under high load conditions was investigated. 500mL of water contained 50mg / L of ammonia nitrogen and 50mg / L of phenol. The sodium bisulfite concentration was 0.1M, the bias voltage was 0, and the irradiance of the xenon lamp was adjusted to 1 standard sun by the illuminometer. The anode was a light-responsive anode composed of a single-sided conductive glass modified with tungsten trioxide and a polycrystalline silicon photocell, and the illumination area was (3cm×3cm). The cathode was a titanium dioxide nanotube mesh cathode modified with bismuth. The aeration rate was set to 10L / min. The removal rate of ammonia nitrogen within 1h reached 81.2% (calculated as total nitrogen removal rate), the removal rate of phenol within 1h reached 79.9%, and the TOC removal rate reached 62.5%.

[0057] Figure 3 and Figure 4 The X-ray diffraction peaks of the tungsten trioxide photoanode and the titanium dioxide nanotube mesh cathode modified with bismuth element are shown, which correspond to the diffraction peaks of tungsten trioxide, tin oxide (conductive glass coating), titanium dioxide and bismuth element, respectively. This shows that the preparation methods of each electrode are correct and feasible. Figure 5The effect of the presence of pollutants on power generation performance was demonstrated. In the presence of pollutants, the current in the system was 16.8% higher than that in the system without pollutants. This result proves that the chemical energy of pollutants can be recovered during the degradation process for power generation. Figure 6 The degradation and electricity generation characteristic curves in the presence of ammonia nitrogen and phenol are shown, with the short-circuit current density reaching 1.21 mA / cm 2 , open circuit voltage is 2.11V, maximum power density (P max ) is 0.88mW / cm 2 , showing relatively good current and power output.

Claims

1. A continuous flow fuel cell module for removing ammonia nitrogen and organic matter from water, characterized in that: The invention comprises a plurality of unit modules, each of which comprises a shell (1), wherein the shell (1) is provided with a water inlet (2), a water outlet (3) and an aeration port (4), wherein an anode (5) and a cathode (6) are arranged in the shell (1), and the shell (1) is filled with fuel and a hole-responsive catalyst, wherein the water inlets (2) and the water outlets (3) of two adjacent unit modules are interconnected to form a pipeline series structure, and the anodes (5) and cathodes (6) in all the unit modules are connected to a circuit control system (7) through a wire; the cathode (6) is a titanium dioxide nanotube mesh electrode modified with a single element of bismuth, and the anode (5) is a light-responsive electrode composed of a single-sided conductive glass modified with tungsten trioxide and a polycrystalline silicon photocell to provide an initial voltage for the operation of the fuel cell module, wherein the fuel contains ammonia nitrogen and organic pollutants, and the hole-responsive catalyst contains sodium bisulfite; and the operating conditions of the continuous flow fuel cell module are: sunlight and continuous blowing of air.

2. The continuous flow fuel cell module for removing ammonia nitrogen and organic matter from water according to claim 1, characterized in that: The shell (1) is made of quartz glass.

3. The continuous flow fuel cell module for removing ammonia nitrogen and organic matter from water according to claim 1, characterized in that: The preparation method of the cathode (6) is as follows: pre-cleaning the titanium mesh with acetone, ethanol and deionized water in sequence; preparing a mixed solution of hydrofluoric acid, nitric acid and deionized water, and immersing the pre-cleaned titanium mesh in the mixed solution to remove surface oxides; winding and fixing three titanium meshes after removing surface oxides with copper wire as anodes, and using platinum electrodes as cathodes, with an electrode spacing of 30 mm, applying a DC voltage of 5 to 30 V, and oxidizing in an ethylene glycol solution containing 0.3% by mass of ammonium fluoride and 2% by volume of deionized water for 1 to 6 hours at a constant temperature with micro-stirring, until the oxidation is complete. After being formed, the titanium dioxide nanotube mesh electrode is taken out and washed with deionized water, and annealed at 500° C. for 2 hours to obtain the titanium dioxide nanotube mesh electrode; bismuth nitrate pentahydrate is ultrasonically dissolved in a deionized water solution of sodium sulfate and disodium ethylenediaminetetraacetic acid, and the prepared titanium dioxide nanotube mesh electrode is used as a working electrode, a platinum electrode is used as a counter electrode, and a silver-silver chloride electrode is used as a reference electrode, and the electrode is electrodeposited for 5 to 30 minutes under a voltage condition of -0.1 to -2 V. After the electrodeposition is completed, the electrode is rinsed and dried to obtain the titanium dioxide nanotube mesh cathode modified with the elemental bismuth element.

4. The continuous flow fuel cell module for removing ammonia nitrogen and organic matter from water according to claim 1, characterized in that: The anode (5) is prepared by dissolving ammonium paratungstate hydrate in deionized water; Subsequently, hydrochloric acid and hydrogen peroxide are added to the solution and stirred until it is completely dissolved and transparent; the transparent solution is transferred to a polytetrafluoroethylene-lined autoclave, and a fluorine-doped tin oxide-coated glass substrate pre-cleaned with acetone, ethanol, and deionized water is immersed in the autoclave containing the above solution with the conductive surface facing downward, and the hydrothermal process is carried out at 160°C for 4 hours, followed by annealing at 500°C for 2 hours; the prepared tungsten trioxide photoanode and the polycrystalline silicon solar cell panel are connected with copper wire to obtain the light-responsive anode of the combination of the single-sided conductive glass modified with tungsten trioxide and the polycrystalline silicon photocell.

5. The continuous flow fuel cell module for removing ammonia nitrogen and organic matter from water according to claim 1, characterized in that: In the fuel, the concentration of ammonia nitrogen is 10-100 mg / L, and the concentration of organic pollutants is no more than 50 mg / L.

6. The continuous flow fuel cell module for removing ammonia nitrogen and organic matter from water according to claim 1, characterized in that: The concentration of sodium bisulfite in the hole-responsive catalyst is no more than 0.1M.

7. An application of a continuous flow fuel cell module for removing ammonia nitrogen and organic matter from water according to any one of claims 1 to 6, characterized in that: The battery module is irradiated with sunlight or a xenon lamp simulating sunlight, fuel and a hole-responsive catalyst are continuously pumped into the water inlet (2) of the first unit module, and air is blown into the aeration port (4) of each unit module.

8. The use according to claim 7, characterized in that In the mixture of the fuel and the hole-responsive catalyst, the concentration of the fuel measured by N element is 30 mg / L NH4 + , the concentration of the hole-responsive catalyst is 0.1M; the flow rate of the fuel and the hole-responsive catalyst is 0.001 to 0.1 L / min; the flow rate of the air is 0.1 to 10 L / min.

9. The use according to claim 7, characterized in that The xenon lamp has a wavelength of 390 to 770 nm and a light intensity of 0.1 to 15 W / cm 2 .

10. The use according to claim 7, characterized in that The single operation time for treating ammonia nitrogen and organic pollutants in the fuel is 15 to 60 minutes.

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