Composite total nitrogen removing bacteria particles, preparation method thereof and method for treating dimethylamine wastewater by using composite total nitrogen removing bacteria particles

Abstract

The invention particularly relates to composite total nitrogen removal bacteria particles, a preparation method thereof and a method for treating dimethylamine wastewater. The method comprises the following steps: preparing biochar; preparing zirconium pre-loaded biochar; preparing a zirconium pre-loaded biochar adsorbent; the method comprises the following steps: respectively placing single flora of nitrifying bacteria, aerobic denitrifying bacteria and ammonifying bacteria in a culture medium, and culturing to a logarithmic growth period to prepare a single strain seed stock solution; performing mixed culture on each single strain seed stock solution to prepare a composite total nitrogen removal flora; adding the composite total nitrogen removal flora into a drying protective agent to prepare bacterial slurry; and mixing the bacterial slurry, an adsorbent and an auxiliary material, carrying out mixed granulation, and drying to obtain the composite total nitrogen removal bacterial particles. The composite total nitrogen removing bacteria particles can synchronously perform ammonification, nitrification and denitrification during use, have adsorption and denitrification performances, can adsorb dimethylamine in wastewater to a large extent, and make composite total nitrogen removing bacteria fully contact pollutants, so that a high degradation rate is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of environmental protection, and in particular to a composite total nitrogen removal bacterial granule and a preparation method thereof, and a method for treating dimethylamine wastewater. Background Art

[0002] Dimethylamine (DMA) is the most widely used and most in-demand chemical raw material among methylamine substances. It is widely used in pesticides, medicines, rubber and leather and other industrial fields, and has become a research hotspot in the field of sewage treatment. At present, the treatment methods for DMA-containing organic amine wastewater at home and abroad mainly include physical method, chemical method and biochemical method. Physical method and chemical method use the basic physical and chemical properties of DMA to achieve the purpose of recovery, separation and degradation. Among them, the physical methods mainly include distillation, extraction, stripping and gas stripping, which are generally suitable for DMA wastewater with higher concentrations; chemical methods include ion exchange, AOPs and other methods. Physical and chemical methods are difficult to meet the emission standards and are usually used as pretreatment process sections for biochemical treatment. DMA will produce a large amount of amine-containing wastewater during production and use. The wastewater has poor biodegradability and has a great impact on the human body, organisms and the environment. It is one of the types of wastewater that is difficult to treat in the field of environmental protection. DMA has poor biodegradability and is prone to produce a large amount of free ammonia in the biochemical process, which poisons microorganisms and stops degradation. General microorganisms have poor removal effects on DMA in the biochemical section.

[0003] Due to its unique denitrification characteristics, the composite total nitrogen removal bacteria can achieve a simultaneous ammoniation, nitrification, and denitrification with one bacterial agent, and has a better effect on the degradation of DMA wastewater than other microorganisms. DMA will produce a large amount of ammonia nitrogen during the ammoniation process, which has a great inhibitory effect on microorganisms and affects the activity of microorganisms. Therefore, it is necessary to continue to find a safe and effective method for degrading DMA wastewater. Summary of the invention

[0004] In order to overcome the shortcomings and deficiencies in the prior art, the object of the present invention is to provide a composite total nitrogen removal bacteria granule and a preparation method thereof. The composite total nitrogen removal bacteria of the present invention can simultaneously carry out ammoniation, nitrification and denitrification when in use, taking into account both adsorption and denitrification performance, and can adsorb dimethylamine in wastewater to a large extent, and make the composite total nitrogen removal bacteria fully contact with pollutants, thereby achieving a higher degradation rate.

[0005] Another object of the present invention is to provide a method for treating dimethylamine wastewater, wherein the method can convert dimethylamine into nitrogen gas by treating the dimethylamine wastewater with a composite total nitrogen removal bacterial agent, and the wastewater treatment efficiency is high.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solution: a method for preparing composite total nitrogen removal bacteria particles, comprising the following steps: (1) Preparation of biochar; (2) using the biochar prepared in step (1) to prepare zirconium preloaded biochar; (3) using the zirconium preloaded biochar prepared in step (2) to prepare a zirconium preloaded biochar adsorbent; (4) placing the single bacterial communities of nitrifying bacteria, aerobic denitrifying bacteria, and ammonifying bacteria in culture medium and culturing them to the logarithmic growth phase to prepare single bacterial strain seed stock solutions; then mixing and culturing the single bacterial strain seed stock solutions to prepare a composite total nitrogen removal bacterial community; (5) Adding a drying protective agent to the composite total nitrogen removal bacterial community prepared in step (4) to prepare a bacterial slurry; mixing the bacterial slurry, the zirconium preloaded biochar adsorbent and the auxiliary materials, granulating the mixture, and then drying the mixture to obtain composite total nitrogen removal bacterial granules.

[0007] In the preparation method of the composite total nitrogen removal bacterial agent particles of the present invention, a Zr-loaded adsorbent, i.e., a zirconium pre-loaded biochar adsorbent, is first prepared, and the zirconium pre-loaded biochar adsorbent has a strong adsorption capacity; then the zirconium pre-loaded biochar adsorbent and auxiliary materials are combined with the composite total nitrogen removal bacterial slurry to obtain composite total nitrogen removal bacterial particles that have both adsorption performance and denitrification, and can simultaneously achieve ammoniation, nitrification and denitrification; the zirconium pre-loaded biochar adsorbent can make the total nitrogen removal bacteria concentratedly distributed in the adsorbent, so after the adsorbent captures the pollutants, the composite total nitrogen removal bacteria can fully and quickly contact the pollutants, greatly improving the overall removal efficiency of DMA.

[0008] The composite total nitrogen removal agent of the present invention can resolve water tension, remove hydrophobic groups wrapped on the surface of pollutants, enhance the migration of pollutant residues to the coupling carrier rich in degradation bacteria, and accelerate the removal of DMA pollution through auxiliary materials and zirconium preloaded biochar adsorbent. Furthermore, in step (1), the fruit shell is crushed, sieved, washed, and then carbonized at high temperature to obtain biochar.

[0009] Furthermore, in step (1), the crushed and cleaned fruit shells are placed in a tubular furnace, nitrogen is introduced, the temperature is increased to 480-520°C at a rate of 4-8°C, the temperature is kept for 3-6 hours, and the shells are cooled to room temperature after carbonization to obtain biochar.

[0010] Furthermore, in step (2), the biochar is added to a sodium hydroxide solution for reflux and filtration, and the filtrate is stored as a sodium hydroxide reserve solution. The solid phase is dried and then added to an alcohol solution, and then a zirconium nitrate solution is added and stirred and aged at room temperature. After filtration, the solid phase is washed and dried to obtain zirconium pre-loaded biochar.

[0011] Furthermore, in step (2), the molar ratio of zirconium ions in the zirconium nitrate solution to OH on the solid surface is 1:4-6, the reflux conditions are reflux at 78-82°C for 10-14h, the drying conditions of the solid phase are drying at 75-85°C for 24-30h, and the alcohol solution is n-propanol or isopropanol.

[0012] Furthermore, in step (3), the sodium hydroxide stock solution prepared in step (2) is added to the zirconium nitrate solution and stirred to obtain a precursor mixed solution; the zirconium preloaded biochar is added to the precursor mixed solution, stirred and aged, filtered, washed and dried to obtain a zirconium preloaded biochar adsorbent.

[0013] Furthermore, in step (3), the molar ratio of OH in the sodium hydrochloride stock solution to zirconium ions in the zirconium nitrate solution is 4-6:1; and the molar mass of zirconium ions in the zirconium nitrate solution to the zirconium pre-loaded biochar is 1.5-2.5 mmol / g.

[0014] Furthermore, in step (4), the single bacterial communities of nitrifying bacteria, aerobic denitrifying bacteria and ammonifying bacteria are respectively placed in culture medium and cultured to the logarithmic growth phase to prepare single strain seed stock solutions; then the single strain seed stock solutions are inoculated into Erlenmeyer flasks according to equal volume ratios, mixed evenly and placed in a shaker, and fermented and cultured for 4 to 6 days at a temperature of 28 to 32° C. and a rotation speed of 160 to 200 r / min to prepare a composite total nitrogen removal bacterial community.

[0015] Furthermore, in step (4), the bacterial concentration of the composite total nitrogen removal bacterial community is 3.8-4.2×10 ^ 10 cfu / mL. Preferably, the bacterial concentration of the composite total nitrogen removal bacterial community is about 4×10 ^10 cfu / mL.

[0016] Furthermore, in step (4), the aerobic denitrifying bacteria is Pseudomonas stinky ), the ammonia-degrading bacteria is Bacillus subtilis, and the nitrifying bacteria is nitrosomonas sp. ) and nitrobacter sp. ) at least one of the following.

[0017] The composite total nitrogen removal bacterial agent of the present invention is composited with nitrifying bacteria, aerobic denitrifying bacteria and ammonifying bacteria. The composite total nitrogen removal bacterial agent can simultaneously realize ammoniation, nitrification and denitrification. The bacterial agent can significantly improve the bacterial removal effect through directional induction, nutritional association and carrier coupling, and improve the colonization, proliferation ability and biological activity of the bacterial strain in the wastewater environment. Furthermore, in step (5), the drying protective agent is at least one of raffinose, dimethyl sulfoxide, trehalose, lactose, glycerol and gelatin; and the auxiliary material is at least one of diatomaceous earth, clay, kaolin, wood ash and vermiculite powder.

[0018] Furthermore, in step (5), the amount of the drying protective agent added is 1-2% of the weight of the composite total nitrogen removal bacterial community; and the weight ratio of the bacterial slurry, the zirconium pre-loaded biochar adsorbent and the auxiliary material is 1:0.75-1:0.75-1.25.

[0019] Furthermore, in step (5), the bacterial slurry, zirconium preloaded biochar adsorbent and auxiliary materials are mixed and granulated and then vacuum dried. The vacuum drying temperature is 30-60° C., the time is 1-10 h, and the water content of the composite total nitrogen removal bacteria is ≤10%.

[0020] The present invention also provides a composite total nitrogen removing bacteria granule, which is prepared by the preparation method of the composite total nitrogen removing bacteria granule.

[0021] The composite total nitrogen removal bacteria granules of the present invention combine adsorbents with nitrifying bacteria, aerobic denitrifying bacteria, and ammonifying bacteria, and can take into account both adsorption and denitrification. It can not only overcome the problem of secondary pollution caused by pollutant overflow during adsorption and regeneration when a single adsorbent is used for wastewater treatment, but also avoid the problem that a single bacterial agent cannot simultaneously ammonify, nitrify, and denitrify when a bacterial agent is used alone for wastewater treatment, and the solubility and capture ability of its bacterial nutrient solution for organic pollutants are poor, and the bacterial agent is lost and the degradation efficiency is low. The present invention combines adsorbents with nitrifying bacteria, aerobic denitrifying bacteria, and ammonifying bacteria, and fully combines the advantages of the adsorbent's ability to capture pollutants in wastewater and the advantages of the bacterial agent in degrading DMA. In addition, the adsorbent also has a certain capture ability for the composite total nitrogen removal bacteria, which can make the microorganisms concentrated in the adsorbent. Therefore, after the adsorbent captures DMA, the microorganisms can fully and quickly contact DMA, greatly improving the overall removal efficiency of DMA wastewater.

[0022] Another object of the present invention is achieved by the following technical solution: a method for treating dimethylamine (DMA) wastewater using a composite total nitrogen removal bacterial agent, (S1) adding an acid-base regulator to dimethylamine wastewater to adjust the pH of the dimethylamine wastewater to 7-8; (S2) adding the composite total nitrogen removal bacteria particles into dimethylamine wastewater to treat the dimethylamine wastewater.

[0023] DMA wastewater has a strong ammonia odor at high concentrations and a fish oil odor at low concentrations. It is easily soluble in water and can be hydrolyzed to produce (CH3)2NH2 + and (OH) ~Its aqueous solution is alkaline. Dimethylamine in the water body will undergo a denitrification reaction and be converted into ammonia nitrogen under the action of microbial decomposition. When the concentration of ammonia nitrogen is too high, it is easy to cause eutrophication of the water body and cause water environment pollution. Microbial denitrification is that nitrogen-containing organic matter is oxidized and decomposed by heterotrophic microbial ammonifying bacteria during the biological treatment process and converted into ammonia nitrogen, which is then converted into nitrate nitrogen by autotrophic nitrifying bacteria, and finally reduced to nitrogen gas by denitrifying bacteria, which escapes from the water to achieve the purpose of denitrification. The acid-base regulator can be at least one of sulfuric acid or hydrochloric acid.

[0024] The beneficial effects of the present invention are: (1) In the preparation method of the composite total nitrogen removal bacterial agent particles of the present invention, a zirconium pre-loaded biochar adsorbent is first prepared, and the zirconium pre-loaded biochar adsorbent has a strong adsorption capacity; then the zirconium pre-loaded biochar adsorbent, auxiliary materials and composite total nitrogen removal bacterial slurry are combined to obtain composite total nitrogen removal bacterial particles that have both adsorption performance and denitrification, and can simultaneously achieve ammoniation, nitrification and denitrification; the zirconium pre-loaded biochar adsorbent can make the total nitrogen removal bacteria concentrated in the adsorbent, so after the adsorbent captures the pollutants, the composite total nitrogen removal bacteria can fully and quickly contact the pollutants, greatly improving the overall removal efficiency of DMA.

[0025] (2) The composite total nitrogen removal bacteria granules of the present invention combine adsorbents with nitrifying bacteria, aerobic denitrifying bacteria, and ammonifying bacteria, and can take into account both adsorption and denitrification. They can not only overcome the problem of secondary pollution caused by pollutant overflow during adsorption and regeneration when a single adsorbent is used for wastewater treatment, but also avoid the problem of a single bacterial agent being unable to simultaneously ammonify, nitrify, and denitrify when a single bacterial agent is used for wastewater treatment, and the poor solubility and capture capacity of the bacterial nutrient solution for organic pollutants, as well as the loss of the bacterial agent and low degradation efficiency.

[0026] (3) The present invention uses a composite total nitrogen removal bacterial agent to treat dimethylamine wastewater, thereby providing a highly efficient dimethylamine wastewater degradation bacterial agent for in-situ removal of dimethylamine-contaminated water bodies, which can convert dimethylamine into nitrogen. DETAILED DESCRIPTION

[0027] In order to facilitate the understanding of those skilled in the art, the present invention is further described below in conjunction with embodiments, and the contents mentioned in the implementation modes are not intended to limit the present invention.

[0028] In an embodiment of the present invention, a method for preparing composite total nitrogen removal bacteria particles comprises the following steps: (1) Preparation of biochar; (2) using the biochar prepared in step (1) to prepare zirconium preloaded biochar; (3) using the zirconium preloaded biochar prepared in step (2) to prepare a zirconium preloaded biochar adsorbent; (4) placing the single bacterial communities of nitrifying bacteria, aerobic denitrifying bacteria, and ammonifying bacteria in culture medium and culturing them to the logarithmic growth phase to prepare single bacterial strain seed stock solutions; then mixing and culturing the single bacterial strain seed stock solutions to prepare a composite total nitrogen removal bacterial community; (5) Adding a drying protective agent to the composite total nitrogen removal bacterial community prepared in step (4) to prepare bacterial slurry; mixing the bacterial slurry, zirconium preloaded biochar adsorbent and auxiliary materials, granulating the mixture, and then drying to obtain composite total nitrogen removal bacterial granules. In some embodiments of the present invention, in step (1), the fruit shell is crushed, sieved, washed, and then carbonized at high temperature to obtain biochar.

[0029] In some embodiments of the present invention, the nut shell is a nut shell, and the nut shell is any one of pistachio shell, macadamia shell, almond shell and pecan shell, preferably pistachio shell.

[0030] In some embodiments of the present invention, in step (1), the fruit shell is crushed, passed through a 100-160 mesh sieve, and washed with deionized water for multiple times before use; then the powder is placed in a tubular furnace, nitrogen is introduced, and the temperature is increased to 480-520° C. at a rate of 4-8° C., kept warm for 3-6 hours, and cooled to room temperature after carbonization to obtain biochar.

[0031] In some embodiments of the present invention, in step (2), biochar is added to a sodium hydroxide solution for reflux and filtration, and the filtrate is stored as a sodium hydroxide reserve solution, the solid phase is dried and then added to an alcohol solution, and then a zirconium nitrate solution is added and stirred and aged at room temperature. After filtration, the solid phase is washed and dried to obtain zirconium pre-loaded biochar.

[0032] In some embodiments of the present invention, in step (2), the molar ratio of zirconium ions in the zirconium nitrate solution to OH on the solid surface is 1:4-6, the reflux conditions are reflux at 78-82°C for 10-14h, the drying conditions of the solid phase are drying at 75-85°C for 24-30h, and the alcohol solution is n-propanol or isopropanol.

[0033] In some embodiments of the present invention, in step (3), the sodium hydroxide stock solution prepared in step (2) is added to the zirconium nitrate solution and stirred to obtain a precursor mixed solution; the zirconium preloaded biochar is added to the precursor mixed solution, stirred and aged, filtered, washed and dried to obtain a zirconium preloaded biochar adsorbent.

[0034] In some embodiments of the present invention, in step (3), the molar ratio of OH in the sodium hydrochloride stock solution to zirconium ions in the zirconium nitrate solution is 4-6:1; the molar mass of zirconium ions in the zirconium nitrate solution to the zirconium pre-loaded biochar is 1.5-2.5 mmol / g.

[0035] In some embodiments of the present invention, in step (4), the single bacterial communities of nitrifying bacteria, aerobic denitrifying bacteria, and ammonifying bacteria are respectively placed in a culture medium and cultured to a logarithmic growth phase to prepare a single strain seed stock solution; then the single strain seed stock solutions are inoculated into a conical flask according to an equal volume ratio, mixed evenly, and placed on a shaker, and fermented and cultured for 4 to 6 days at a temperature of 28 to 32° C. and a rotation speed of 160 to 200 r / min to prepare a composite total nitrogen removal bacterial community; the bacterial cell concentration of the composite total nitrogen removal bacterial community is about 4×10 ^10 cfu / mL.

[0036] In some embodiments of the present invention, in step (4), the aerobic denitrifying bacteria is Pseudomonas stinky ), the ammonia-degrading bacteria is Bacillus subtilis, and the nitrifying bacteria is nitrosomonas sp. ) and nitrobacter sp. ) at least one of the following.

[0037] In some embodiments of the present invention, the nitrosomonas sp. ) and nitrobacter sp. ) is in a mass ratio of 0.5~2:0.5~2.

[0038] In some embodiments of the present invention, in step (5), the drying protective agent is at least one of raffinose, dimethyl sulfoxide, trehalose, lactose, glycerol and gelatin; and the auxiliary material is at least one of diatomaceous earth, clay, kaolin, wood ash and vermiculite powder.

[0039] In some embodiments of the present invention, in step (5), the amount of the drying protective agent added is 1-2% of the weight of the composite total nitrogen removal bacterial community; the weight ratio of the bacterial slurry, the zirconium pre-loaded biochar adsorbent and the auxiliary material is 1:0.75-1:0.75-1.25.

[0040] In some embodiments of the present invention, in step (5), the bacterial slurry, zirconium preloaded biochar adsorbent and auxiliary materials are mixed and granulated and then vacuum dried. The vacuum drying temperature is 30-60° C., the time is 1-10 h, and the water content of the composite total nitrogen removal bacteria is ≤10%.

[0041] In some embodiments of the present invention, a composite total nitrogen-removing bacteria granule is prepared by the above-mentioned preparation method of the composite total nitrogen-removing bacteria granule.

[0042] In some embodiments of the present invention, the composite total nitrogen removal bacterial agent particles include composite total nitrogen removal bacteria, zirconium-loaded biochar adsorbent and diatomaceous earth, and the mass ratio of the composite total nitrogen removal bacteria, zirconium-loaded biochar adsorbent and diatomaceous earth is 0.4~0.7:0.7~1.2:1.

[0043] In some embodiments of the present invention, a method for treating dimethylamine wastewater using a composite total nitrogen removal bacterial agent comprises the following steps: (S1) adding concentrated sulfuric acid to dimethylamine wastewater to adjust the pH of the dimethylamine wastewater to 7-8; (S2) adding the composite total nitrogen removal bacteria particles into dimethylamine wastewater to adsorb and degrade the dimethylamine wastewater.

[0044] Example 1 This embodiment provides a method for preparing composite total nitrogen removal bacteria particles, comprising the following steps: (1) Preparation of biochar The pistachio shells were crushed, passed through a 100-mesh sieve, and then washed with deionized water for three times, placed in a tubular furnace and introduced with nitrogen, heated to 500°C at a rate of 5°C, kept at this temperature for 3 hours to carbonize, and then cooled to room temperature.

[0045] (2) Zirconium preloaded biochar Add 5 g of biochar to 60 mL mol•L -1 The solution was refluxed at 80 °C for 12 h. The filtrate was filtered and stored as a reserve flow of sodium hydroxide. The reflux phase was dried at 80 °C for 24 h. The amount of NaOH on the biochar surface was measured and added to the n-propanol solution. According to the molar ratio of zirconium ions in the zirconium nitrate solution and OH on the solid surface of 1:5, 0.1 mol·L -1 The zirconium nitrate solution was then added and stirred at room temperature for 2 hours, aged for 6 hours, and the solid phase was washed and dried after filtration to obtain zirconium pre-loaded biochar.

[0046] (3) Preparation of adsorbent Slowly add the sodium hydroxide stock solution in step (2) to 50 ml 0.1 mol•L -1 The precursor mixture is prepared by stirring a zirconium nitrate solution, and the zirconium preloaded biochar is added to the precursor mixture, wherein the molar mass of zirconium ions in the precursor mixture accounts for 2 mmol / g of the zirconium preloaded biochar, stirring and aging for 6 hours, filtering and washing, and drying at 80°C for 24 hours to obtain an adsorbent.

[0047] (4) Preparation of composite total nitrogen removal bacterial community The single bacterial colonies of nitrifying bacteria, aerobic denitrifying bacteria, and ammonifying bacteria were cultured in the culture medium until the logarithmic growth phase (cultured at 30°C and 180 r / min shaking conditions) to prepare a single strain seed stock solution with a bacterial cell concentration of about 4×10 ^10 cfu / mL, wherein the aerobic denitrifying bacteria is Pseudomonas stinky ), the ammonia-forming bacteria is Bacillus subtilis subtle) The nitrifying bacteria are nitrosomonas sp. ) and nitrobacter sp. ), the nitrite bacteria and nitrate bacteria were mixed in a mass ratio of 1:1; then, the seed stock solutions of each single strain were inoculated into a triangular flask in an equal volume ratio, mixed evenly, and placed in a shaker at 30°C, 180r / min, and fermented for 5 days to prepare a highly efficient composite total nitrogen removal bacterial community, with a bacterial concentration of about 4×10 ^10 cfu / mL.

[0048] (5) Composite total nitrogen removal bacteria granulation The fermented composite total nitrogen removal bacteria (solid content controlled at 60%) was added with raffinose (content of 1.5% of the weight of the composite total nitrogen removal bacteria) to obtain a bacterial slurry, the bacterial slurry, adsorbent and diatomaceous earth were mixed in a mass ratio of 1:0.8:1, and vacuum dried at 40°C for 8h to obtain composite total nitrogen removal bacteria particles with a moisture content of 4.1%.

[0049] The present embodiment provides a composite total nitrogen removal bacterial agent particle, which is prepared by the above preparation method. The composite total nitrogen removal bacterial agent particle comprises composite total nitrogen removal bacteria, zirconium-loaded biochar adsorbent and diatomaceous earth, and the mass ratio of composite total nitrogen removal bacteria, zirconium-loaded biochar adsorbent and diatomaceous earth is 0.591:0.8:1.

[0050] This embodiment also provides a method for treating dimethylamine (DMA) wastewater using a composite total nitrogen removal bacterial agent, comprising the following steps: (S1) adding concentrated sulfuric acid to dimethylamine wastewater to adjust the pH of the dimethylamine wastewater to 7-8; (S2) adding the composite total nitrogen removal bacteria particles into dimethylamine wastewater to treat the dimethylamine wastewater.

[0051] Example 2 This embodiment provides a method for preparing composite total nitrogen removal bacteria particles, comprising the following steps: (1) Preparation of biochar The macadamia nut shells were crushed, passed through a 150-mesh sieve, and then washed with deionized water for 4 times, placed in a tube furnace and purged with nitrogen. The temperature was raised to 600°C at a rate of 5°C, kept at this temperature for 4 hours to carbonize, and then cooled to room temperature; (2) Zirconium preloaded biochar Add 5g of biochar to 60mL of 1mol•L -1 The solution was refluxed at 80 °C for 14 h, and the filtrate was stored as a sodium hydroxide stock solution after filtration. The solid phase was dried at 85 °C for 30 h, and the amount of NaOH on the biochar surface was measured. After adding the n-propanol solution, 0.1 mol·L was slowly added according to the molar ratio of zirconium ions in the zirconium nitrate solution and OH on the solid surface of 1:4. -1 The zirconium phosphate solution was added, and then the zirconium nitrate solution was added and stirred at room temperature for 2 hours. After aging for 6 hours, the back phase was filtered, washed and dried to obtain the zirconium pre-loaded biochar.

[0052] (3) Preparation of adsorbent The sodium hydroxide stock solution in step (2) was slowly added to 50 ml of 0.1 mol·1 -1 The precursor mixture is prepared by stirring a zirconium nitrate solution, and the zirconium pre-loaded biochar is added to the precursor mixture, wherein the molar mass of zirconium ions in the precursor mixture is 1.5 mmol / g of the zirconium pre-loaded biochar. The mixture is stirred for 2 hours and aged for 6 hours. After filtration, the mixture is washed and dried at 80°C for 24 hours to obtain an adsorbent.

[0053] (4) Preparation of composite total nitrogen removal bacterial community The single bacterial colonies of nitrifying bacteria, aerobic denitrifying bacteria and ammonifying bacteria were placed in the culture medium and cultured to the logarithmic growth phase (cultured at 30°C and 180 r / min shaking conditions), and the single bacterial colonies of nitrifying bacteria, aerobic denitrifying bacteria and ammonifying bacteria were placed in the culture medium and cultured to the logarithmic growth phase (cultured at 30°C and 180 r / min shaking conditions), and the single bacterial strain seed stock solution was prepared, and the bacterial concentration was about 4×10 ^10 cfu / mL; wherein the aerobic denitrifying bacteria is Pseudomonas stinky ), the ammonia-forming bacteria is Bacillus subtilis subtle) The nitrifying bacteria are nitrosomonas sp. ) and nitrobacter sp.), the nitrite bacteria and nitrate bacteria were mixed in a mass ratio of 1:1; then, the seed stock solutions of each single strain were inoculated into a triangular flask in an equal volume ratio, mixed evenly, and placed in a shaker at 30°C, 180r / min, and fermented for 5 days to prepare a highly efficient composite total nitrogen removal bacterial community, with a bacterial concentration of about 4×10 ^10 cfu / mL.

[0054] (5) Composite total nitrogen removal bacteria granulation The fermented composite total nitrogen removal bacteria (solid content controlled at 60%) was added with trehalose (the content of which was 12% of the weight of the composite total nitrogen removal bacteria) to obtain a bacterial slurry. The bacterial slurry, adsorbent and diatomaceous earth were mixed and granulated in a mass ratio of 1:0.75:1, and vacuum dried at 45°C for 10 h to obtain composite total nitrogen removal bacteria granules with a moisture content of 4.1%.

[0055] The present embodiment provides a composite total nitrogen removal bacterial agent particle, which is prepared by the above preparation method. The composite total nitrogen removal bacterial agent particle comprises composite total nitrogen removal bacteria, zirconium-loaded biochar adsorbent and diatomaceous earth, and the mass ratio of composite total nitrogen removal bacteria, zirconium-loaded biochar adsorbent and diatomaceous earth is 0.536:0.75:1.

[0056] This embodiment also provides a method for treating dimethylamine (DMA) wastewater using a composite total nitrogen removal bacterial agent, comprising the following steps: (S1) adding concentrated sulfuric acid to dimethylamine wastewater to adjust the pH of the dimethylamine wastewater to 7-8; (S2) adding the composite total nitrogen removal bacteria particles into dimethylamine wastewater to treat the dimethylamine wastewater.

[0057] Example 3 In this embodiment, a composite total nitrogen removal bacterial agent particle is provided, comprising a composite total nitrogen removal bacterial slurry, a zirconium-loaded biochar adsorbent and diatomaceous earth, and the mass ratio of the composite total nitrogen removal bacterial slurry, the zirconium-loaded biochar adsorbent and the diatomaceous earth is 1:1:1.

[0058] This embodiment provides a method for preparing composite total nitrogen removal bacteria particles, comprising the following steps: (1) Preparation of biochar The almond shells were crushed, passed through a 100-mesh sieve, and then washed with deionized water for 5 times, placed in a tube furnace and purged with nitrogen. The temperature was raised to 700°C at a rate of 5°C, kept at this temperature for 5 hours to carbonize, and then cooled to room temperature; (2) Zirconium preloaded biochar Add 5 g of biochar to 60 mL mol•L -1The solution was refluxed at 80 °C for 16 h, and the filtrate was stored as a reserve flow of sodium hydroxide after filtration. The reflux phase was dried at 80 °C for 40 h, and the amount of NaOH on the biochar surface was measured. After adding it to the n-propanol solution, 0.1 mol·L was slowly added according to the molar ratio of zirconium ions in the zirconium nitrate solution and OH on the solid surface of 1:3. -1 The zirconium nitrate solution was then added and stirred at room temperature for 2 hours, aged for 6 hours, and the solid phase was washed and dried after filtration to obtain zirconium pre-loaded biochar.

[0059] (3) Preparation of adsorbent Slowly add the sodium hydroxide stock solution in step (2) to 50 ml 0.1 mol·L -1 The precursor mixture is prepared by stirring the zirconium nitrate solution, and the zirconium pre-loaded biochar is added to the precursor mixture, wherein the molar mass of zirconium ions in the precursor mixture is 2.5 mmol / g of the zirconium pre-loaded biochar. The mixture is stirred and aged for 6 hours, filtered and washed, and dried at 80°C for 24 hours to obtain an adsorptive composite total nitrogen removal bacterial agent with a moisture content of 4.1%.

[0060] (4) Preparation of composite total nitrogen removal bacterial community The nitrifying bacteria, aerobic denitrifying bacteria, and ammonia-forming bacteria were placed in a culture medium and cultured to a logarithmic growth phase (cultured at 30°C and 180 r / min shaking conditions), and the nitrifying bacteria, aerobic denitrifying bacteria, and ammonia-forming bacteria were placed in a culture medium and cultured to a logarithmic growth phase (cultured at 30°C and 180 r / min shaking conditions) to prepare a single strain seed stock solution, wherein the aerobic denitrifying bacteria is Pseudomonas stinky ), the ammonia-forming bacteria is Bacillus subtilis subtle) The nitrifying bacteria are nitrosomonas sp. ) and nitrobacter sp. ), the nitrite bacteria and nitrate bacteria were mixed in a mass ratio of 1:1; then, the seed stock solutions of each single strain were inoculated into a triangular flask in an equal volume ratio, mixed evenly, and placed in a shaker at 30°C, 180r / min, and fermented for 5 days to prepare a highly efficient composite total nitrogen removal bacterial community, with a bacterial concentration of about 4×10 ^10 cfu / mL.

[0061] (5) Compound total nitrogen removal bacteria granulation The fermented composite total nitrogen removal bacteria (solid content controlled at 60%) was added with lactose (content being 1% of the weight of the composite total nitrogen removal bacteria) to obtain a bacterial slurry. The bacterial slurry, adsorbent and diatomaceous earth were mixed and granulated in a mass ratio of 1:1:1, and vacuum dried at 50°C for 24 hours to obtain composite total nitrogen removal bacteria granules with a moisture content of 4.1%.

[0062] The present embodiment provides a composite total nitrogen removal bacterial agent granule, which is prepared by the above preparation method. The composite total nitrogen removal bacterial agent granule comprises composite total nitrogen removal bacteria, zirconium-loaded biochar adsorbent and diatomaceous earth, and the mass ratio of composite total nitrogen removal bacteria, zirconium-loaded biochar adsorbent and diatomaceous earth is 0.594:1:1.

[0063] This embodiment also provides a method for treating dimethylamine (DMA) wastewater using a composite total nitrogen removal bacterial agent, comprising the following steps: (S1) adding concentrated sulfuric acid to dimethylamine wastewater to adjust the pH of the dimethylamine wastewater to 7-8; (S2) adding the composite total nitrogen removal bacteria particles into dimethylamine wastewater to treat the dimethylamine wastewater.

[0064] Example 4 This embodiment provides a method for preparing composite total nitrogen removal bacteria particles, comprising the following steps: (1) Preparation of biochar The pecan shells were crushed, passed through a 100-mesh sieve, and then washed with deionized water for 6 times, placed in a tubular furnace and introduced with nitrogen, heated to 800°C at a rate of 5°C, kept at this temperature for 6 hours to carbonize, and then cooled to room temperature.

[0065] (2) Zirconium preloaded biochar Add 5 g of biochar to 60 mL mol•L -1 The solution was refluxed at 80 °C for 18 h, and the filtrate was stored as a reserve flow of sodium hydroxide after filtration. The reflux phase was dried at 80 °C for 48 h, and the amount of NaOH on the biochar surface was measured. After adding it to the n-propanol solution, 0.1 mol•L was slowly added according to the molar ratio of zirconium ions in the zirconium nitrate solution and OH on the solid surface of 1:5. -1 The zirconium nitrate solution was then added and stirred at room temperature for 2 hours, aged for 6 hours, and the solid phase was washed and dried after filtration to obtain zirconium pre-loaded biochar.

[0066] (3) Preparation of adsorbent Slowly add the sodium hydroxide stock solution in step (2) to 50 ml 0.1 mol•L -1The precursor mixture is prepared by stirring a zirconium nitrate solution, and the zirconium preloaded biochar is added to the precursor mixture, wherein the molar mass of zirconium ions in the precursor mixture is 1 mmol / g of the zirconium preloaded biochar. The mixture is stirred and aged for 6 hours, filtered and washed, and dried at 80°C for 24 hours to obtain an adsorbent.

[0067] (4) Preparation of composite total nitrogen removal bacterial community The single bacterial colonies of nitrifying bacteria, aerobic denitrifying bacteria, and ammonifying bacteria were cultured in the culture medium until the logarithmic growth phase (cultured at 30°C and 180 r / min shaking conditions) to prepare a single strain seed stock solution with a bacterial cell concentration of about 4×10 ^10 cfu / mL, wherein the aerobic denitrifying bacteria is Pseudomonas stinky ), the ammonia-forming bacteria is Bacillus subtilis subtle) The nitrifying bacteria are nitrosomonas sp. ) and nitrobacter sp. ), the nitrite bacteria and nitrate bacteria were mixed in a mass ratio of 1:1; then, the seed stock solutions of each single strain were inoculated into a triangular flask in an equal volume ratio, mixed evenly, and placed in a shaker at 30°C, 180r / min, and fermented for 5 days to prepare a highly efficient composite total nitrogen removal bacterial community, with a bacterial concentration of about 4×10 ^10 cfu / mL.

[0068] (5) Composite total nitrogen removal bacteria granulation The fermented composite total nitrogen removal bacteria (solid content controlled at 60%) was added with glycerol (content of which was 1.50% of the weight of the composite total nitrogen removal bacteria) to obtain a bacterial community. The bacterial community, adsorbent and kaolin were mixed and granulated in a mass ratio of 1:0.8:1, and vacuum dried at 60°C for 36 hours to obtain composite total nitrogen removal bacteria granules with a moisture content of 4.1%.

[0069] The present embodiment provides a composite total nitrogen removal bacterial agent particle, which is prepared by the above preparation method. The composite total nitrogen removal bacterial agent particle comprises composite total nitrogen removal bacteria, zirconium-loaded biochar adsorbent and diatomaceous earth, and the mass ratio of composite total nitrogen removal bacteria, zirconium-loaded biochar adsorbent and diatomaceous earth is 0.591:0.8:1.

[0070] This embodiment also provides a method for treating dimethylamine (DMA) wastewater using a composite total nitrogen removal bacterial agent, comprising the following steps: (S1) adding concentrated sulfuric acid to dimethylamine wastewater to adjust the pH of the dimethylamine wastewater to 7-8; (S2) adding the composite total nitrogen removal bacteria particles into dimethylamine wastewater to treat the dimethylamine wastewater.

[0071] Example 5 In this embodiment, a composite total nitrogen removal bacterial agent particle is provided, comprising a composite total nitrogen removal bacterial slurry, a zirconium-loaded biochar adsorbent and diatomaceous earth, and the mass ratio of the composite total nitrogen removal bacteria, the zirconium-loaded biochar adsorbent and the diatomaceous earth is 1:0.8:1.

[0072] This embodiment provides a method for preparing composite total nitrogen removal bacteria particles, comprising the following steps: (1) Preparation of biochar The pistachio shells were crushed, passed through a 100-mesh sieve, and then washed with deionized water for 7 times, placed in a tubular furnace and purged with nitrogen. The temperature was raised to 500°C at a rate of 5°C, kept at this temperature for 5 hours to carbonize, and then cooled to room temperature; (2) Zirconium preloaded biochar Add 6 g of biochar to 60 mL mol•L -1 The solution of sodium oxychloride was refluxed at 80°C for 12h, otherwise the contents of Example 5 are exactly the same as those of Example 1). After filtration, the filtrate was stored as a reserve flow of sodium hydroxide. The reflux phase was dried at 80°C for 48h. The amount of NaOH on the surface of biochar was measured and added to the n-propanol solution. 0.1 mol•L was slowly added dropwise according to the molar ratio of zirconium ions in the zirconium nitrate solution to OH on the solid surface of 1:4. -1 The zirconium nitrate solution was then added and stirred at room temperature for 2 hours, aged for 6 hours, and the solid phase was washed and dried after filtration to obtain zirconium pre-loaded biochar.

[0073] (3) Preparation of adsorbent Slowly add the sodium hydroxide stock solution in step (2) to 50 ml 0.1 mol•L -1 The precursor mixture is prepared by stirring a zirconium nitrate solution, and the zirconium preloaded biochar is added to the precursor mixture, wherein the molar mass of zirconium ions in the precursor mixture accounts for 2 mmol / g of the zirconium preloaded biochar, stirring and aging for 6 hours, filtering and washing, and drying at 80°C for 24 hours to obtain an adsorbent.

[0074] (4) Preparation of composite total nitrogen removal bacterial community The single bacterial colonies of nitrifying bacteria, aerobic denitrifying bacteria, and ammonifying bacteria were cultured in the culture medium until the logarithmic growth phase (cultured at 30°C and 180 r / min shaking conditions) to prepare a single strain seed stock solution with a bacterial cell concentration of about 4×10 ^10 cfu / mL; wherein the aerobic denitrifying bacteria is Pseudomonas stinky ), the ammonia-forming bacteria is Bacillus subtilis subtle)The nitrifying bacteria are nitrosomonas sp. ) and nitrobacter sp. ), the nitrite bacteria and nitrate bacteria were mixed in a mass ratio of 1:1; then, the seed stock solutions of each single strain were inoculated into a triangular flask in an equal volume ratio, mixed evenly, and placed in a shaker at 30°C, 180r / min, and fermented for 5 days to prepare a highly efficient composite total nitrogen removal bacterial community, with a bacterial concentration of about 4×10 ^10 cfu / mL.

[0075] (5) Composite total nitrogen removal bacteria granulation The fermented composite total nitrogen-removing bacteria (solid content controlled at 60%) was added with gelatin (content of 1.50% of the weight of the composite total nitrogen-removing bacteria) to obtain a bacterial slurry. The bacterial slurry, adsorbent and kaolin were mixed and granulated in a mass ratio of 1:0.8:1, and vacuum dried at 40°C for 24 hours to obtain composite total nitrogen-removing bacteria granules with a moisture content of 4.1%.

[0076] The present embodiment provides a composite total nitrogen removal bacterial agent particle, which is prepared by the above preparation method. The composite total nitrogen removal bacterial agent particle comprises composite total nitrogen removal bacteria, zirconium-loaded biochar adsorbent and diatomaceous earth, and the mass ratio of composite total nitrogen removal bacteria, zirconium-loaded biochar adsorbent and diatomaceous earth is 0.591:0.8:1.

[0077] This embodiment also provides a method for treating dimethylamine (DMA) wastewater using a composite total nitrogen removal bacterial agent, comprising the following steps: (S1) adding concentrated sulfuric acid to dimethylamine wastewater to adjust the pH of the dimethylamine wastewater to 7-8; (S2) adding the composite total nitrogen removal bacteria particles into dimethylamine wastewater to treat the dimethylamine wastewater.

[0078] Comparative Example 1 This comparative example provides an adsorbent particle, wherein the adsorbent particle is a zirconium preloaded biochar adsorbent; a method for preparing the adsorbent particle comprises the following steps: (1) Preparation of biochar The pistachio shells were crushed, passed through a 100-mesh sieve, and then washed with deionized water three times. The shells were placed in a tubular furnace and nitrogen was introduced. The temperature was raised to 500°C at a rate of 5°C, kept at this temperature for 3 hours for carbonization, and then cooled to room temperature. (2) Zirconium preloaded biochar Add 5 g of biochar to 60 mL mol•L -1The solution was refluxed at 80 °C for 18 h, and the filtrate was stored as a reserve flow of sodium hydroxide after filtration. The reflux phase was dried at 80 °C for 48 h, and the amount of NaOH on the biochar surface was measured. After adding it to the n-propanol solution, 0.1 mol•L was slowly added according to the molar ratio of zirconium ions in the zirconium nitrate solution and OH on the solid surface of 1:4. -1 The zirconium nitrate solution was then added and stirred at room temperature for 2 hours, aged for 6 hours, and the solid phase was washed and dried after filtration to obtain zirconium pre-loaded biochar.

[0079] (3) Preparation of adsorbent Slowly add the sodium hydroxide stock solution in step (2) to 50 ml 0.1 mol•L -1 The precursor mixture is prepared by stirring a zirconium nitrate solution, and the zirconium preloaded biochar is added to the precursor mixture, wherein the molar mass of zirconium ions in the precursor mixture accounts for 2 mmol / g of the zirconium preloaded biochar, stirring and aging for 6 hours, filtering and washing, and drying at 80°C for 24 hours to obtain an adsorbent.

[0080] (4) Preparation of inactivated composite total nitrogen removal bacterial flora The single bacterial colonies of nitrifying bacteria, aerobic denitrifying bacteria, and ammonifying bacteria were cultured in the culture medium until the logarithmic growth phase (cultured at 30°C and 180 r / min shaking conditions) to prepare a single strain seed stock solution with a bacterial cell concentration of about 4×10 ^10 cfu / mL. After that, the seed stock solution of each single strain was inoculated into a triangular flask in an equal volume ratio, mixed evenly, and placed in a shaker at 30°C, 180r / min, and fermented for 5 days to form a highly efficient composite total nitrogen removal bacterial community, with a bacterial concentration of about 4×10 ^ 10 cfu / mL. The bacterial colony was then sterilized by high pressure steam sterilization to inactivate the complex total nitrogen removal bacterial colony.

[0081] (5) Granulation of inactivated composite total nitrogen removal bacteria The inactivated composite total nitrogen removal bacteria (solid content controlled at 60%) was added with trehalose (the content of which was 12% of the weight of the composite total nitrogen removal bacteria) to obtain a bacterial slurry, and the bacterial slurry, adsorbent and diatomaceous earth were mixed and granulated in a mass ratio of 1:0.8:1, and vacuum dried at 45°C for 24 hours to obtain inactivated composite total nitrogen removal bacteria particles with a moisture content of 4.1%, i.e., adsorbent particles.

[0082] Comparative Example 2 The difference between this comparative example and Example 1 is that the zirconium-loaded biochar adsorbent prepared in Example 1 is mixed with diatomaceous earth and bacterial slurry to prepare a particle mixture.

[0083] The treatment effect of the composite total nitrogen removal bacteria particles of Examples 1 to 5, the adsorptive particles of Comparative Example 1, and the particle mixture of Comparative Example 2 on dimethylamine wastewater was measured, comprising the following steps: The simulated wastewater with a total nitrogen component of DMA was prepared, and the pH of the simulated wastewater was adjusted to 7.5 using dilute hydrochloric acid, and then divided into 7 parts for aeration in an aerobic tank for 24 hours for biodegradation. The fillers in the aerobic tank were respectively filled with the composite total nitrogen removal bacteria particles of Examples 1 to 5, the adsorbent particles of Comparative Example 1, and the particle mixture of Comparative Example 2. After biodegradation treatment, they were respectively used as Experiments 1 to 7, and the changes in the total nitrogen content of the total wastewater before and after the treatment of Experiments 1 to 7 were tested. The results are shown in Table 1: Table 1 Total nitrogen removal effect of different test groups

[0084] As can be seen from Table 1, after biological treatment with the composite total nitrogen removal bacteria granules of the present invention, the total nitrogen removal rate can reach more than 98%, while in Experiments 6 and 7, the total nitrogen content in the wastewater is relatively high. This is because the biological tower in Experiment 6 contains only zirconium-loaded biochar adsorbents. Although it has better adsorption capacity and can adsorb DMA in the wastewater, it is a physical effect and cannot fundamentally solve the degradation problem. Although Experiment 7 has both zirconium-loaded biochar adsorbents and composite total nitrogen removal bacteria, it is a simple physical mixture. It is only a combination of the physical adsorption effect of the zirconium-loaded biochar adsorbent and the effect of the composite total nitrogen removal bacteria. It cannot play a role similar to the present invention in that the composite total nitrogen removal bacteria are concentrated in the adsorbent. Therefore, after the adsorbent captures organic pollutants, the composite total nitrogen removal bacteria can fully and quickly contact with the organic pollutants, greatly improving the overall removal efficiency of DMA wastewater. Therefore, its removal effect is still worse than that of the composite total nitrogen removal bacteria granules of the present invention.

[0085] The above specific embodiments are further explanations of the technical solutions and beneficial effects of the present invention, and are not limitations of the implementation methods. For those skilled in the art, any obvious replacements that do not depart from the concept of the present invention are within the protection scope of the present invention.

Claims

1. A method for preparing composite total nitrogen removal bacteria particles, characterized in that: The steps include: (1) Preparation of biochar; (2) using the biochar prepared in step (1) to prepare zirconium preloaded biochar; (3) using the zirconium preloaded biochar prepared in step (2) to prepare a zirconium preloaded biochar adsorbent; (4) placing the single bacterial communities of nitrifying bacteria, aerobic denitrifying bacteria, and ammonifying bacteria in culture medium and culturing them to the logarithmic growth phase to prepare single bacterial strain seed stock solutions; then mixing and culturing the single bacterial strain seed stock solutions to prepare a composite total nitrogen removal bacterial community; (5) Adding a drying protective agent to the composite total nitrogen removal bacterial community prepared in step (4) to prepare a bacterial slurry; mixing the bacterial slurry, the zirconium preloaded biochar adsorbent and the auxiliary materials, granulating the mixture, and then drying the mixture to obtain composite total nitrogen removal bacterial granules.

2. The method for preparing the composite total nitrogen removal bacteria granules according to claim 1, characterized in that: In step (1), the fruit shells are crushed, sieved, washed, and then carbonized at high temperature to obtain biochar.

3. The method for preparing the composite total nitrogen removal bacteria granules according to claim 1, characterized in that: In step (2), the biochar is added to a sodium hydroxide solution for reflux and filtration, and the filtrate is stored as a sodium hydroxide reserve solution. The solid phase is dried and then added to an alcohol solution, and then a zirconium nitrate solution is added and stirred and aged at room temperature. After filtration, the solid phase is washed and dried to obtain zirconium pre-loaded biochar.

4. The method for preparing the composite total nitrogen removal bacteria granules according to claim 3, characterized in that: In step (2), the molar ratio of zirconium ions in the zirconium nitrate solution to OH on the solid surface is 1:4-6, the reflux conditions are reflux at 78-82°C for 10-14 hours, the drying conditions of the solid phase are drying at 75-85°C for 24-30 hours, and the alcohol solution is n-propanol or isopropanol.

5. The method for preparing the composite total nitrogen removal bacteria granules according to claim 1, characterized in that: In step (3), the sodium hydroxide stock solution prepared in step (2) is added to the zirconium nitrate solution and stirred to obtain a precursor mixed solution; the zirconium preloaded biochar is added to the precursor mixed solution, stirred and aged, filtered, washed and dried to obtain a zirconium preloaded biochar adsorbent; the molar ratio of OH in the sodium hydrochloride stock solution to the zirconium ion in the zirconium nitrate solution is 4-6:1; the molar mass of zirconium ions in the zirconium nitrate solution to the zirconium preloaded biochar is 1.5-2.5 mmol / g.

6. The method for preparing the composite total nitrogen removal bacteria granules according to claim 1, characterized in that: In step (4), the single bacterial communities of nitrifying bacteria, aerobic denitrifying bacteria and ammonifying bacteria are respectively placed in culture medium and cultured to the logarithmic growth phase to prepare single bacterial strain seed stock solutions; then the single bacterial strain seed stock solutions are inoculated into a conical flask according to an equal volume ratio, mixed evenly and placed on a shaker, and fermented and cultured for 4 to 6 days at a temperature of 28 to 32° C. and a rotation speed of 160 to 200 r / min to prepare a composite total nitrogen removal bacterial community.

7. The method for preparing the composite total nitrogen removal bacteria granules according to claim 6, characterized in that: In step (4), the aerobic denitrifying bacteria is Pseudomonas, the ammonia-degrading bacteria is Bacillus subtilis, and the nitrifying bacteria is at least one of the genus Nitrite Bacteria and the genus Nitrobacter.

8. The method for preparing the composite total nitrogen removal bacteria granules according to claim 1, characterized in that: In step (5), the amount of the drying protective agent added is 1-2% of the weight of the composite total nitrogen removal bacterial community; the weight ratio of the bacterial slurry, the zirconium pre-loaded biochar adsorbent and the auxiliary material is 1:0.75-1:0.75-1.

25.

9. A composite total nitrogen removal bacterial granule, characterized in that: The composite total nitrogen removal bacteria granules are prepared by the preparation method of any one of claims 1 to 8.

10. A method for treating dimethylamine wastewater using a composite total nitrogen removal bacterial agent, characterized in that: The steps include: (S1) adding an acid-base regulator to dimethylamine wastewater to adjust the pH of the dimethylamine wastewater to 7-8; (S2) Adding the composite total nitrogen removal bacteria granules described in claim 9 into dimethylamine wastewater to treat the dimethylamine wastewater.

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