Method for strengthening deep ultraviolet simultaneous deamination and denitration by CO2 aeration

Abstract

The present application relates to a kind of CO2 aeration enhanced deep ultraviolet synchronous denitrification and deamination method, specifically related to in the wastewater containing certain concentration nitrate nitrogen and ammonium nitrogen, moderate exposure CO2 gas, accompanied by deep ultraviolet radiation, produce a large amount of CO2 And carbonate radical, electron of ammonium nitrogen is taken to reduce nitrate nitrogen, realize the purpose of synchronous reduction of nitrate nitrogen and ammonium nitrogen.The present application innovatively combines deep ultraviolet photolysis technology and CO2 aeration selective radical generation reaction, and simultaneously utilizes the acidification effect of CO2 on water body to inhibit the stripping effect of ammonium nitrogen, effectively guarantees the sufficient supply of electron donor, realizes the efficient synchronous removal of nitrate nitrogen and ammonia nitrogen.The present application has important significance for controlling water body eutrophication and improving aquatic ecological environment.

Description

I. TECHNICAL FIELD

[0001] The present application relates to the technical field of environmental pollution control, and particularly relates to a method for deep ultraviolet synchronous deamination and denitration enhanced by CO2 aeration. II. BACKGROUND

[0002] The problem of nitrogen pollution in water environment has long plagued water quality improvement and social development. Food residues and other nitrogen-containing organic matter contained in urban domestic sewage are decomposed by microorganisms to produce ammonia nitrogen and nitrate nitrogen. Industrial wastewater, especially coking wastewater and synthetic ammonia fertilizer plant wastewater, contains a large amount of nitrogen. When discharged into water bodies, it will cause ammonia nitrogen and nitrate nitrogen pollution. In addition, the excessive use of nitrogen fertilizers makes a large amount of nitrogen enter groundwater or rivers and lakes through water and soil loss, further aggravating ammonia nitrogen and nitrate nitrogen pollution. The ammonia gas in automobile exhaust dissolves in water to form ammonia nitrogen pollution. The level of nitrogen pollution is usually related to the emission intensity of pollution sources, the self-purification capacity of water bodies, and the degree of human activity interference. High concentrations of ammonia nitrogen can lead to a decrease in dissolved oxygen in water bodies, causing suffocation and death of fish and other aquatic animals, and disrupting the balance of the water ecosystem. Secondly, ammonia nitrogen can also disrupt the balance of microorganisms in water bodies, affecting water biodiversity and the stability of the food chain. For human health, ammonia nitrogen entering the water supply system can react with chlorine disinfectants to produce nitrosamines, which are closely related to the occurrence of cancer. Therefore, the problem of ammonia nitrogen and nitrate nitrogen pollution in water environment needs to be solved urgently.

[0003] Currently, there are various technologies for denitrification of wastewater and natural water. Biological denitrification technology uses specific microorganisms to convert nitrogen compounds in water into nitrogen gas, effectively reducing nitrogen content. Among them, nitrification-denitrification is a mature biological denitrification method, which uses the synergistic effect of nitrifying bacteria and denitrifying bacteria to convert ammonia nitrogen into nitrogen gas and release it into the atmosphere. Biological denitrification process usually has the advantages of low energy consumption, simple operation, no need to add chemical agents, etc., but the operation of biological denitrification technology requires certain time and suitable environmental conditions, such as temperature, pH value, dissolved oxygen, etc. At the same time, biological denitrification process has high demand for carbon source, if the wastewater lacks sufficient carbon source, additional carbon source may need to be added, increasing the operation cost. In addition, the treatment effect of biological denitrification process on high-concentration ammonia nitrogen wastewater is limited, and the occupied area is large; chemical denitrification technology converts nitrogen compounds in water into insoluble precipitates by adding chemical agents, thereby achieving denitrification. For example, breakpoint chlorination method oxidizes ammonia nitrogen into nitrogen gas by adding excess chlorine or sodium hypochlorite. Chemical denitrification technology usually has the advantages of high treatment efficiency, fast reaction speed, and no temperature influence, but it needs to consume a large amount of chemical agents, and the operation cost is high. At the same time, the addition of chemical agents may cause secondary pollution, such as chloroamines and chlorinated organic compounds as by-products. In addition, the treatment effect of chemical denitrification technology on some specific nitrogen compounds (such as nitrate and nitrite) may not be ideal. Physical denitrification technology uses physical processes to remove nitrogen compounds in water, such as gas stripping and membrane separation. These methods usually have the advantages of simple operation, no need to add chemical agents, and no secondary pollution. The equipment investment cost of physical denitrification technology is high, and the treatment effect on high-concentration nitrogen pollution is limited. In addition, physical denitrification technology usually needs to be operated under specific environmental conditions, such as temperature, pressure, etc., which limits its widespread application in practical application.

[0004] Ultraviolet denitrification technology uses deep ultraviolet band (usually UV-C, wavelength between 100-280 nanometers) ultraviolet light as energy source. When ultraviolet light irradiates the water containing nitrogen compounds, the high-energy photons can excite the nitrogen compound molecules in the water, making them enter the excited state. In the excited state, the chemical bonds within the nitrogen compound molecules become unstable and are prone to chemical reactions, thereby realizing the decomposition and transformation of nitrogen compounds. For some nitrogen compounds, such as nitrite and nitrate, deep ultraviolet light can directly photolyze them into nitrogen, oxygen or other harmless substances. This process does not require the addition of any chemical agents, and is a green and environmentally friendly denitrification method. However, the effect of deep ultraviolet denitrification technology is influenced by many factors, including the wavelength, intensity, and irradiation time of the ultraviolet light source. In addition, water quality conditions (such as pH value, temperature, turbidity, etc.) and the type and amount of photocatalyst also affect the denitrification effect. These problems are mainly due to the characteristics of active free radicals generated by photolysis process, such as high activity, short lifetime and easy quenching.

[0005] The current ultraviolet denitrification technology has problems in the field of nitrogen control in water. It is urgent to develop a new process method that can handle ammonia nitrogen and nitrate nitrogen and improve the total nitrogen removal efficiency. This is of great significance for the control of nitrogen pollution in complex water bodies. This new treatment method will bring significant economic and social benefits. By improving the treatment efficiency, reducing maintenance costs, etc., the operating costs of environmental protection projects such as water treatment can be reduced, and the economic benefits of the project can be improved, which is helpful to human health and social sustainable development. III. SUMMARY

[0006] The present application is made in view of the problems in the prior art. According to the above analysis, the main problem and obstacle of low efficiency of ultraviolet denitrification is the mutual quenching and disappearance of strong active species generated by ultraviolet excitation, which leads to the unnecessary consumption and waste of most energy. For example, reducing radicals such as hydrated electrons or hydrogen radicals can effectively degrade nitrate, but strong oxidizing radicals produced by photolysis of water will cause these reducing radicals to be rapidly quenched, which will significantly weaken the degradation efficiency of nitrate. At this time, if a reducing species is introduced to consume these strong oxidizing radicals in time, the reducing radicals can be preserved to a greater extent to enhance the effect of reducing denitrification. Conversely, for the oxidation removal of ammonia nitrogen under ultraviolet excitation, there are similar problems. If an oxidizing species is provided to eliminate the quenching effect of reducing species in time, the removal efficiency of ammonia nitrogen can also be greatly improved. These have been confirmed in previous studies. Therefore, finding and optimizing the "anti-quenching agent" suitable for the corresponding denitrification reaction is crucial to the improvement of denitrification efficiency.

[0007] In theory, ammonia nitrogen and nitrate nitrogen can act as "anti-quenching agents" for each other. From the chemical valence state, the nitrogen element in ammonium is -3 valence, which has strong reducing property; while the nitrogen element in nitrate is +5 valence, which has strong oxidizing property. The two will undergo a reduction reaction, but in reality, this is not the case. The ammonium ion in water has a very stable tetrahedral structure, and few oxidizing agents can achieve the oxidative decomposition of ammonium ion except Cl radicals; while the nitrate ion also has a certain stability. Under the condition of coexistence of the two, only under the condition of very high concentration, such as pure ammonium nitrate solid, at high temperature and energy excitation conditions (400℃), the reduction reaction can be realized and explosion can be triggered. Therefore, it is not realistic to directly use the reduction reaction of ammonia nitrogen and nitrate nitrogen to achieve denitrification in actual water environment.

[0008] However, vacuum ultra violet (VUV) photolysis and electron shuttle effect in the presence of CO2 can create conditions for this type of reaction. On the one hand, VUV can directly decompose water, at the same time generating a large number of hydroxyl radicals and hydrogen radicals or hydrated electrons, reducing nitrate to nitrite; ammonia nitrogen is oxidized to hydrazine. However, it is difficult for the two to further react to become nitrogen, so the electron shuttle is needed to mediate the redox reaction between the two. CO2 radical is a highly reactive nucleophilic radical, which also has a certain electrophilic ability under certain conditions, which determines that electrons can shuttle between hydrazine and nitrite through CO2 radical, realizing the redox of the two, fully utilizing the energy of light radiation, and effectively avoiding energy waste.

[0009] In order to achieve the above purpose, the technical scheme of the present application is a method for strengthening deep ultra violet synchronous deamination and denitrification by CO2 aeration, characterized in that the method comprises the following steps:

[0010] Step 1, selecting sewage containing both nitrate nitrogen and ammonium nitrogen, wherein the molar ratio of nitrate nitrogen to ammonium nitrogen should be close to 3:2, and the total inorganic nitrogen concentration should not be higher than 100 mg / L, and the water should not contain ions with significant redox ability at a concentration higher than 500 mg / L, such as Cl - , ClO - , ClO2 - , Br - , BrO3 - , I-, PO4 3- , S 2- , SO3 2- , S2O8 2- , S2O3 2- , etc., in order to avoid quenching of hydrated electrons and hydroxyl radicals;

[0011] Step 2, pretreating the sewage in step 1 to remove suspended solids in the water by filtering with a precision filter, and adsorbing colority with activated carbon to avoid negative effects on the subsequent deep ultra violet photolysis process;

[0012] Step 3, transferring the pretreated sewage obtained in step 2 to a tower type photolysis reactor, which has a deep ultra violet light source fixed in the middle, and a quartz waterproof cover outside the ultra violet light source to protect it, while ensuring that the deep ultra violet light can effectively radiate into the water body. The sewage forms a circulating flow outside the reactor to strengthen mass transfer and play a role in washing and cleaning the quartz waterproof cover;

[0013] Step 4, continuously aerating the sewage in step 3 with nitrogen gas for 30 min to remove dissolved oxygen in the water, and then adding 10 mg / L of magnesium powder to maintain the reducing property of the system and inhibit the precipitation of Ca2+ ion precipitation;

[0014] Step 5, one end of the porous aeration disc is placed at the bottom of the tower photolysis reactor described in step 3, and the other end is connected with a CO2 steel cylinder through a conduit, and a flow meter is adjusted to introduce CO2 gas into the sewage at a moderate aeration speed;

[0015] Step 6, after 5 minutes of CO2 aeration, start the deep ultraviolet light source, and after the light source radiation is gradually stabilized, start the external circulation pump to start the reaction and collect water samples;

[0016] Step 7, during the reaction, deep ultraviolet light radiation decomposes water to produce a large amount of oxidizing and reducing free radicals such as hydroxyl radicals, hydrated electrons, ozone and hydrogen atoms, realizing the simultaneous removal of nitrate nitrogen and ammonium nitrogen, and realizing the electron shuttle between nitrate nitrogen and ammonium nitrogen through high-energy radiation as a medium, so as to achieve the purpose of synergistic degradation. At this time, the conversion trend of nitrate nitrogen and ammonium nitrogen should be monitored in time to avoid excessive conversion of nitrate nitrogen to ammonium nitrogen to cause a large amount of waste of ultraviolet radiation energy. If it is found that ammonium nitrogen is excessively generated and causes the molar ratio of nitrate nitrogen to ammonium nitrogen to be lower than 1:1, a small amount of NaCl should be added in time to consume ammonia nitrogen to prevent and reverse the reaction trend.

[0017] For the above technical solution, it is further limited that the main wavelength range of the deep ultraviolet radiation in step 3 is 100 to 200 nm, preferably 185 nm.

[0018] For the above technical solution, it is further limited that the aeration amount of CO2 in step 5 is adjusted according to the concentration of nitrate nitrogen and ammonium nitrogen in the wastewater, the volume of the reactor and the empty tower gas speed to ensure sufficient generation of carbonate radicals, and at the same time the aeration amount should not be too large to cause a large amount of bubbles to shield the light radiation and energy loss.

[0019] The present application has the advantages of:

[0020] 1) The deep ultraviolet denitrification technology has the advantages of high efficiency, environmental protection and no secondary pollution;

[0021] 2) Compared with traditional biological denitrification and chemical denitrification technology, the deep ultraviolet denitrification technology does not need to add chemical reagents, avoiding the secondary pollution problem that may be caused by chemical reagents;

[0022] 3) At the same time, the technology has fast processing speed and strong adaptability, and can be applied to denitrification treatment under different water quality conditions. IV. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the specific embodiments of the present application, the drawings used in the specific embodiment part of the description are briefly described below. Figure 1 It is a schematic diagram of the reaction mechanism of CO2 aeration reinforced deep ultraviolet simultaneous ammonium and nitrate removal.

[0024] Figure 2 Schematic diagram of a tower type photolysis reactor for CO2 aeration enhanced deep ultraviolet simultaneous ammonia and nitrate removal, wherein the reference signs are as follows: 1-reactor shell; 2-deep ultraviolet lamp (with quartz waterproof cover); 3-reflux / water inlet pump; 4-aeration plate; 5-water inlet; 6-reflux port; 7-water outlet / effluent port; 8-aeration plate gas supply pipe; 9-water inlet; 10-reflux pipe; 11-CO2 gas bubbles.

[0025] Figure 3 Ammonia nitrogen and nitrate nitrogen concentration changes with treatment time in the process of treating pond water by the CO2 aeration enhanced deep ultraviolet simultaneous ammonia and nitrate removal method in Example 2 of the present application; V. DETAILED DESCRIPTION

[0026] The present application will be described in detail below in conjunction with the accompanying drawings and examples:

[0027] Example 1:

[0028] A method for CO2 aeration enhanced deep ultraviolet simultaneous ammonia and nitrate removal, the method comprising the following steps: first, selecting wastewater containing both nitrate nitrogen and ammonium nitrogen, wherein the molar ratio of nitrate nitrogen to ammonium nitrogen should be close to 3:2, and the total inorganic nitrogen concentration should not be higher than 100 mg / L, and the water should not contain ions with significant redox ability such as Cl - , ClO - , ClO2 - , Br - , BrO3 - , I-, PO4 3- , S 2- , SO3 2- , S2O8 2- , S2O3 2- , etc. in a concentration higher than 500 mg / L to avoid quenching of hydrated electrons and hydroxyl radicals; then pretreating the wastewater to remove suspended solids in the water by filtering with a precision filter and to remove color by adsorption with activated carbon to avoid negative effects on the subsequent deep ultraviolet photolysis process; transferring the pretreated wastewater to a tower type photolysis reactor, which has a deep ultraviolet light source fixed in the middle, and the ultraviolet light source is protected by a quartz waterproof cover outside, which can also ensure that the deep ultraviolet light is effectively radiated into the water, wherein the main wavelength range of the deep ultraviolet radiation is 100 to 200 nm, preferably 185 nm, and the wastewater forms a circulating flow outside the reactor to enhance mass transfer and to wash and clean the quartz waterproof cover; continuously aerating the wastewater in step 3 with nitrogen gas for 30 min to remove dissolved oxygen in the water, and then adding 10 mg / L of magnesium powder to maintain the reducing property of the system and inhibit Ca 2+ion release; one end of the porous aerator is placed at the bottom of the tower photolysis reactor described in step 3, and the other end is connected with a CO2 steel cylinder through a conduit, and the flow meter is adjusted to introduce CO2 gas into the contaminated wastewater at a moderate aeration rate. The amount of CO2 aeration is adjusted according to the concentration of nitrate nitrogen and ammonium nitrogen in the wastewater, the volume of the reactor, and the empty tower gas velocity to ensure sufficient carbonate radical generation, while the aeration rate should not be too large, which will cause a large number of bubbles to produce light radiation shielding and energy loss. After 5 minutes of CO2 aeration, the deep ultraviolet light source is started, and after the light source radiation is gradually stabilized, the outer circulation pump is started to start the reaction and collect water samples; during the reaction, the deep ultraviolet light radiation decomposes water to generate a large amount of hydroxyl radical, hydrated electron, ozone, hydrogen atom and other redox radicals, realizing the simultaneous removal of nitrate nitrogen and ammonium nitrogen, and realizing the electron shuttle between nitrate nitrogen and ammonium nitrogen with high-energy radiation as a medium, so as to achieve the purpose of synergistic degradation (see Figure 1 ). At this time, the conversion trend of nitrate nitrogen and ammonium nitrogen should be monitored in time to avoid excessive conversion of nitrate nitrogen to ammonium nitrogen to cause a large amount of ultraviolet radiation energy to be wasted. If it is found that ammonium nitrogen is excessively generated and causes the molar ratio of nitrate nitrogen to ammonium nitrogen to be lower than 1:1, a small amount of NaCl should be added in time to consume ammonia nitrogen to prevent and reverse the reaction trend.

[0029] Example 2:

[0030] Based on the method described in Example 1, a tower photolysis reactor is built as follows Figure 2 ) :

[0031] The reactor shell (1) is used to isolate the ultraviolet radiation and support the reactor, and contains the wastewater to be treated; the reactor is internally provided with a plurality of vertical parallel arranged deep ultraviolet light lamps (2) with quartz waterproof lampshades, which can realize uniform light coverage of the reactor; the backflow / water inlet pump (3) is used to inject the wastewater (3) into the bottom of the reactor through the inlet (5), and the aerator (4) can expose the CO2 gas delivered by the gas guide pipe (8) into the reaction cavity to form uniform CO2 bubbles; the reactor is provided with a backflow pipeline (10), which can backflow the wastewater overflowing from the upper part to the front end of the backflow / water inlet pump (3) through the backflow port (6) to strengthen the water flow to strengthen the mass transfer and flush the quartz lamp tube; during the reaction, the wastewater treated by ammonia and denitrification can be discharged from the reactor through the water outlet (7).

[0032] The above reactor is used to treat the contaminated pond water collected from a certain place in Beijing, and the concentrations of ammonia nitrogen and nitrate nitrogen in the water are about 15 mg / L and 10 mg / L respectively, the empty tower gas velocity is set to 1.0 h -1 , the backflow ratio is 1:1, the irradiation intensity is 180 μW / cm 2 , HRT=2 h, and the CO2 aeration rate is 0.2 (v / v). The reactor is operated in two modes of internal circulation and continuous flow, respectively. In the mode of internal circulation (Figure 3 ), after 2h treatment, the ammonia and nitrate concentrations were analyzed by a nitrogen analyzer, and the ammonia and nitrate concentrations were reduced to 2.17 mg / L and 2.04 mg / L, respectively, with removal rates of 85.5% and 79.6%, respectively; in the continuous flow mode, the removal rates of ammonia and nitrate were stable >72% after continuous operation for 200h.

[0033] Example 3:

[0034] The reactor described in Example 2 was used to treat groundwater from a certain location in Beijing, with ammonia and nitrate concentrations of about 2.55 mg / L and 3.43 mg / L, respectively, and a CO2 aeration rate of 0.3 (v / v), with the remaining conditions being the same as in Example 2. The reactor was operated in both internal circulation and continuous flow modes. In the internal circulation mode, after 2h treatment, the ammonia and nitrate concentrations were reduced to 1.12 mg / L and 0.17 mg / L, respectively, with removal rates of 56.2% and 95%, respectively. In the continuous flow mode, the removal rates of ammonia and nitrate were stable >45% after continuous operation for 200h.

[0035] Example 4:

[0036] The reactor described in Example 2 was used to treat groundwater from a certain location in Jinan, Shandong, with ammonia and nitrate concentrations of about 1.25 mg / L and 2.34 mg / L, respectively, and a CO2 aeration rate of 0.5 (v / v), with the remaining conditions being the same as in Example 2. The reactor was operated in both internal circulation and continuous flow modes. In the internal circulation mode, after 1.5h treatment, the ammonia and nitrate concentrations were reduced to 0.13 mg / L and 0.29 mg / L, respectively, with removal rates of 89% and 87.6%, respectively. In the continuous flow mode, the removal rates of ammonia and nitrate were stable >85% after continuous operation for 200h.

[0037] Example 5:

[0038] The reactor described in Example 2 was used to treat secondary biochemical tail water from a sewage treatment plant in Xingtai, Hebei, with ammonia and nitrate concentrations of about 0.75 mg / L and 0.77 mg / L, respectively, and a reflux ratio of 2:1, a CO2 aeration rate of 0.45 (v / v), with the remaining conditions being the same as in Example 2. The reactor was operated in both internal circulation and continuous flow modes. In the internal circulation mode, after 3h treatment, the ammonia and nitrate concentrations were reduced to 0.04 mg / L and 0.05 mg / L, respectively, with removal rates of 95% and 93.5%, respectively. In the continuous flow mode, the removal rates of ammonia and nitrate were stable >90% after continuous operation for 200h.

[0039] The above detailed description is only for specific illustration of the spirit of the present application, and the protection scope of the present application is not limited thereto. For those skilled in the art, other embodiments can be easily made by changing, replacing or modifying the disclosed technical contents in the present specification, and these other embodiments should be covered in the protection scope of the present application.

Claims

1. A method for simultaneous ammonia and nitrification removal using CO2 aeration enhanced by deep ultraviolet light, characterized in that, The method includes the following steps: Step 1: Select wastewater containing both nitrate nitrogen and ammonium nitrogen, wherein the concentrations of ammonia nitrogen and nitrate nitrogen are 15 mg / L and 10 mg / L, or 2.55 mg / L and 3.43 mg / L, or 1.25 mg / L and 2.34 mg / L, or 0.75 mg / L and 0.77 mg / L, respectively; the total inorganic nitrogen concentration is not higher than 100 mg / L; and the water must not contain ions with significant redox capabilities at a concentration higher than 500 mg / L to avoid quenching hydrated electrons and hydroxyl radicals. The ions with significant redox capabilities include Cl... - ,ClO - ClO2 - ,Br - BrO3 - I - PO4 3- S 2- SO3 2- S2O8 2- S2O3 2- One or more of the following; Step 2: Pre-treat the wastewater described in Step 1 by using a fine filter to remove suspended solids and activated carbon to adsorb and remove color, thus avoiding negative impacts on the subsequent deep ultraviolet photolysis process. Step 3: Transfer the pretreated wastewater obtained in Step 2 to a tower-type photolysis reactor. A deep ultraviolet light source is fixed in the middle of the reactor. The ultraviolet light source is protected by a quartz waterproof cover, which can ensure that the deep ultraviolet light can effectively radiate into the water. The wastewater forms a circulating flow outside the reactor to enhance mass transfer and to flush and clean the quartz waterproof cover. The main wavelength range of the deep ultraviolet light source is 100 to 200 nm. Step 4: The wastewater from Step 3 is continuously aerated with nitrogen for 30 minutes to remove dissolved oxygen. Then, 10 mg / L of magnesium powder is added to maintain the reducing properties of the system and inhibit the growth of calcium in the water. 2+ The precipitation of ions; Step 5: Place the porous aeration disc at the bottom of the tower-type photolysis reactor described in Step 3, connect it to the CO2 cylinder with a conduit, and adjust the flow meter to aerate the CO2 gas at a suitable aeration rate. Step 6: After CO2 aeration for 5 minutes, start the deep ultraviolet light source. After the light source radiation gradually stabilizes, turn on the external circulation pump to start the reaction and collect water samples. Step 7: During the reaction, deep ultraviolet radiation decomposes water to generate a large number of hydroxyl radicals, hydrated electrons, ozone, or hydrogen atom redox radicals, achieving simultaneous removal of nitrate nitrogen and ammonium nitrogen. At the same time, secondary CO2 and carbonate radicals act as mediators to achieve electron shuttle between nitrate nitrogen and ammonium nitrogen, so as to achieve synergistic degradation. At this time, the conversion trend of nitrate nitrogen and ammonium nitrogen should be monitored at any time to avoid excessive conversion of nitrate nitrogen to ammonium nitrogen, which would lead to a large waste of ultraviolet radiation energy. If it is found that ammonium nitrogen is excessively generated and the molar ratio of nitrate nitrogen to ammonium nitrogen is less than 1:1, a small amount of NaCl should be added in time to consume ammonia nitrogen and prevent and reverse the reaction trend.

2. The method for simultaneous ammonia and nitrification removal using CO2 aeration enhanced by deep ultraviolet light as described in claim 1, characterized in that, The preferred wavelength of the deep ultraviolet light source mentioned in step 3 is 185nm.

3. The method for simultaneous ammonia and nitrification removal using CO2 aeration enhanced by deep ultraviolet light as described in claim 1, characterized in that, In step 5, the CO2 aeration rate is adjusted according to the concentration of nitrate nitrogen and ammonium nitrogen in the wastewater, the reactor volume, and the empty tower gas velocity to ensure sufficient carbonate free radical generation. At the same time, the aeration rate should not be too high to avoid generating a large number of bubbles that shield light radiation.

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