A sewage treatment agent for treating nitrogen pollution and a preparation method and application thereof

Abstract

The application discloses a sewage treatment agent for treating nitrogen pollution, which comprises a porous carrier and microbial inoculum adsorbed on the porous carrier. The preparation method of the sewage treatment agent comprises the following steps: heating microcrystalline wax in a water bath to complete melting, adding the porous carrier and stirring, adding microbial inoculum and nutrient substances into the completely melted solution and continuing to stir, and finally pouring into a prepared mold and naturally cooling to obtain the sewage treatment agent. The sewage treatment agent adopts platinum nanoparticles and porous hexagonal boron nitride fiber composite carrier, the Pt and the hexagonal boron nitride fiber composite carrier prepared by a block copolymer self-assembly micelle method have no other impurity residues, and the carrier after compounding has good uniformity. The microbial inoculum, nutrient agent, porous carrier and wax are combined together, a biofilm is generated on the surface of the carrier to purify water quality, and the microbial sewage treatment agent made of the wax is suspended on the surface of water or sinks to the bottom of water by using an external object, so that secondary pollution to the water environment can be avoided.

Description

Technical Field

[0001] This invention belongs to the field of wastewater treatment technology, specifically relating to a wastewater treatment agent for treating nitrogen pollution and its preparation method. Background Technology

[0002] Nitrogen in water exists in four forms: organic nitrogen, ammonia nitrogen, nitrite nitrogen, and nitrate nitrogen. Nitrogen is widely present in nature and is of great importance to organisms, being the main element for the synthesis of amino acids in cells.

[0003] The nitrogen in wastewater from refining and chemical enterprises is mainly ammonia nitrogen and nitrate nitrogen. Currently, most of these are removed using biological nitrification and denitrification methods. However, due to the poor biodegradability of refining and chemical wastewater, large amounts of carbon sources, such as glucose, acetic acid, and sodium acetate, are often required to be added. Adding carbon sources increases operating costs and also causes secondary pollution to the water body. With the increasing stringency of wastewater discharge standards, existing wastewater treatment facilities are no longer sufficient for advanced treatment and face the need for upgrading and renovation.

[0004] Traditional nitrate treatment processes mainly include physicochemical methods (such as ion exchange, reverse osmosis, electrodialysis, etc.), chemical methods (active metal denitrification, catalytic denitrification, etc.), and biological methods (heterotrophic and autotrophic denitrification, etc.).

[0005] Among them, biological treatment technology utilizes denitrifying bacteria to produce NO3. - -N acts as an electron acceptor in the denitrification reaction, converting NO3- into nitrogen. - The technology of reducing nitrogen (N-) to nitrogen (N2) and releasing it into the atmosphere. Based on the form of carbon source that denitrifying bacteria can utilize, it can be further divided into heterotrophic denitrification and autotrophic denitrification technologies. Currently, biological treatment methods are generally considered the most economical and effective way to remove nitrate pollutants from water.

[0006] Biological denitrification technology mainly includes heterotrophic denitrification and autotrophic denitrification. Currently, most wastewater treatment processes utilize heterotrophic bacteria to remove nitrates through denitrification. In wastewater treatment, substances such as methanol, ethanol, and sodium acetate are commonly used as organic carbon sources and electron donors for the growth of heterotrophic microorganisms. In addition, some inorganic substances, such as hydrogen, iron, sulfur, and their compounds, can also replace organic matter as electron donors for autotrophic bacteria in the denitrification process.

[0007] Chinese Patent 202010912963.4, entitled "A Wastewater Treatment Agent and Its Preparation Method," discloses a wastewater treatment agent comprising, by weight, 10-20 parts of honeycomb porous carbon fiber / nanozirconia composite material, 10-15 parts of polydopamine-modified palygorskite material, 15-30 parts of porous zeolite powder, and 13-18 parts of polyaluminum chloride. This invention also discloses a method for preparing the wastewater treatment agent. The wastewater treatment agent prepared by this invention has a large specific surface area, high activity, and strong adsorption capacity, effectively removing pollutants from wastewater. The preparation method of this wastewater treatment agent is simple, the conditions are mild, and the resulting wastewater treatment agent has good dispersibility and does not cause secondary pollution to water bodies. However, the honeycomb porous carbon fiber / nanozirconia composite material used relies on the adsorption capacity of the carrier to treat wastewater, but its adsorption capacity is limited, thus limiting its wastewater treatment capacity. Moreover, as adsorption saturates, its adsorption rate slows down, affecting the wastewater treatment rate.

[0008] In Chinese Patent 202111118116.1, entitled "A Wastewater Treatment Method," the specific method involves using a treatment agent to adsorb and degrade leachate, followed by separation of the treatment agent. The treatment agent comprises a porous carrier and microbial agents adsorbed onto the porous carrier. The porous carrier is a rare earth-TiO2 / diatomaceous earth / graphene composite aerogel microsphere; the rare earth element is any one or more of La, Sm, or Ce. This invention's treatment method exhibits excellent treatment effects on leachate, achieving COD removal rates exceeding 95%, NH3-N removal rates exceeding 93%, BOD5 removal rates exceeding 86%, and color removal rates exceeding 65%. It has broad application prospects in the field of wastewater treatment. However, the loading performance of this rare earth-TiO2 / diatomite / graphene composite aerogel microsphere carrier is poor, resulting in incomplete loading of the bacterial agent and low treatment efficiency of the prepared wastewater treatment agent. Moreover, the use of carrier materials to immobilize microorganisms into granular spheres, mixing bacteria, microorganisms, and enzymes with the material, can lead to the inactivation of some bacteria, microorganisms, and enzymes. Furthermore, the prepared granular spheres will directly sink to the bottom of the wastewater during water purification. With the increase in usage, undissolved particles will accumulate at the bottom of the pond. If this continues for a long time, these incompletely dissolved particles will deteriorate the ecological environment at the bottom of the pond. Summary of the Invention

[0009] The purpose of this invention is to provide a wastewater treatment agent for treating nitrogen pollution and its preparation method, so as to solve the problems mentioned in the background art.

[0010] To achieve the above objectives, the present invention provides the following technical solution: a wastewater treatment agent for treating nitrogen pollution, comprising a porous carrier and microbial agents adsorbed on the porous carrier.

[0011] Preferably, the porous carrier is a composite carrier of platinum nanoparticles and porous hexagonal boron nitride fibers.

[0012] Preferably, in any of the above embodiments, the preparation method of the platinum nanoparticles and porous hexagonal boron nitride fiber composite carrier includes the following steps:

[0013] S1: Heat 100-200ml of deionized water to 60-70℃;

[0014] S2: Melamine and boric acid are added to the prepared deionized water in a mass ratio of 1-1.5:1 and stirred at a rate of 200 r / min. During this process, after the drugs dissolve, a white flocculent precipitate is formed. With continued stirring, the flocculent precipitate disappears and becomes a milky liquid, resulting in a mixed solution.

[0015] S3: Heat the water bath to 90℃, stir at 200 rpm for the first 1-2 hours, then increase the stirring speed to 400 rpm at 5 rpm / min until the water is completely evaporated. Then place the obtained product in a forced-air drying oven at 90-100℃ for 12-18 hours under ultraviolet light, and then cool it to room temperature to obtain the precursor.

[0016] S4: After grinding the precursor, place it in a tube furnace and heat it to 600-800℃ at a rate of 5℃ / min under an argon atmosphere with a gas flow rate of 150-200 sccm. After reaching 800℃, keep the argon gas constant and introduce ammonia gas at a flow rate of 50-100 sccm. After holding at this temperature for 5-10 hours, turn off the ammonia gas and cool it down to 200-300℃ at a rate of 5℃ / min. Then, allow it to cool naturally to room temperature to obtain porous hexagonal boron nitride nanofibers.

[0017] S5: Disperse 50-100 mg of PS-P2VP block copolymer in 10-20 ml of toluene solvent, and stir in the dark for 3-7 days until completely dissolved;

[0018] S6: Add an appropriate amount of H2PtCl6·6H2O to the above solution to make the mass ratio of porous hexagonal boron nitride nanofibers to Pt 1:1.5. Continue to stir in the dark for 3-7 days to obtain a reverse micelle solution loaded with platinum salt.

[0019] S7: Add the porous hexagonal boron nitride nanofibers from step S4 to the above solution, and stir with a magnetic stirrer at room temperature for 36-72 hours to obtain the product;

[0020] S8: After drying the product, anneal it in air at 450-650℃ for 20-60 min to obtain a composite carrier of platinum nanoparticles and porous hexagonal boron nitride fibers.

[0021] Preferably, in any of the above embodiments, the intensity of the ultraviolet light is 100-10000 uw / cm. 2 .

[0022] Preferably, in any of the above embodiments, the microbial agent includes facultative anaerobic autotrophic denitrifying bacteria.

[0023] Preferably, in any of the above embodiments, the autotrophic denitrifying bacteria include *Trichophyton aquatilis* and *Oligotroph ...

[0024] Preferably, in any of the above embodiments, the method for preparing the microbial agent includes: inoculating the seed culture of *Trichophyton aquatilis* and *Oligotrophomonas* into the culture medium at 1% v / v for enrichment culture; during fermentation, introducing sterile air into the tank; stirring at 100-300 rpm; fermentation temperature at 30-40℃; fermentation time at 40-60 h; and collecting the culture medium, which is the microbial agent of *Trichophyton aquatilis* and *Oligotrophomonas*.

[0025] Preferably, each liter of the above-mentioned culture medium contains 1.0-2.0g of sodium bicarbonate, 0.5-0.7g of ferrous sulfate, 0.1-0.3g of potassium hydrogen phosphate, 0.5-0.7g of potassium dihydrogen phosphate, 0.1-0.2g of calcium chloride, 0.1-0.2g of magnesium sulfate, 0.1-0.3g of potassium nitrate, and 2-4ml of trace elements, wherein each liter of trace elements contains 0.1-0.2g of zinc sulfate, 0.5-0.7g of ferrous sulfate, 0.5-0.7g of copper sulfate, 0.1-0.2g of manganese chloride, 0.1-0.2g of cobalt chloride, and 1.0-1.5g of EDTA.

[0026] A method for preparing a wastewater treatment agent for treating nitrogen pollution includes the following steps:

[0027] Heat the microcrystalline wax in a water bath at 80-90℃ until it is completely melted. During this process, stir at 50-100 rpm for 5-10 minutes every 20 minutes. Add the porous carrier during the third stirring.

[0028] Microbial agents and nutrients are added to the completely melted solution and stirred at 50-100 rpm for 30 minutes to ensure that the microbial agents and nutrients are evenly distributed in the wax liquid and adhered to the porous carrier. The nutrients are culture medium, biopolyester and diatomaceous earth. All materials are prepared into nutrient granules with a slow-release effect through granulation process.

[0029] Finally, pour the mixture into the prepared mold and allow it to cool naturally to obtain the wastewater treatment agent.

[0030] The application of wastewater treatment agents in wastewater treatment is specifically to remove nitrates through the denitrification process.

[0031] The technical effects and advantages of this invention are as follows: This invention uses platinum nanoparticles and porous hexagonal boron nitride fiber composite carriers. The Pt and hexagonal boron nitride fiber composites prepared by block copolymer self-assembly micelle method have no other impurities. The composite carrier material exhibits good uniformity and has the excellent high temperature stability and large surface area of ​​porous hexagonal boron nitride fiber itself. It also has functions such as organic dye adsorption, oil-water separation, and gas adsorption, and can effectively load more microbial agents and disperse them evenly.

[0032] A mixture of *Trichomonas aquatilis* and *Oligotrophosporium* in a 1:1 ratio was used. *Trichomonas aquatilis* has greater applicability to different water quality and environmental conditions, while *Oligotrophosporium* is a strain with good denitrification ability under low temperature and acid-alkaline conditions. The synergistic treatment of the two has a wider range of applicability and better treatment effect.

[0033] When preparing wastewater treatment agents, microcrystalline wax is used to combine bacterial agents, nutrients, porous carriers, and wax together. By generating a biofilm on the carrier surface, the water quality is purified. Using external materials, the wax-based microbial wastewater treatment agent is suspended on the surface of the water or sinks to the bottom. This achieves the goal of not causing secondary pollution to the water environment, controlling the reaction process, and being environmentally friendly. Attached Figure Description

[0034] Figure 1 This is a flowchart illustrating the preparation process of the wastewater treatment agent of the present invention. Detailed Implementation

[0035] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings. It should be noted that these descriptions are for the purpose of aiding understanding the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0036] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature.

[0037] Example 1:

[0038] A wastewater treatment agent for treating nitrogen pollution includes a composite carrier of platinum nanoparticles and porous hexagonal boron nitride fibers, and a composite bacterial agent of aquatic Trichomonas aquatilis and Oligotrophospora attached to the composite carrier, wherein Trichomonas aquatilis and Oligotrophospora are present.

[0039] The preparation method of this platinum nanoparticle-porous hexagonal boron nitride fiber composite carrier includes:

[0040] S1: Heat 100ml of deionized water to 60℃;

[0041] S2: Melamine and boric acid are added to the prepared deionized water in a mass ratio of 1:1 and stirred at a rate of 200 r / min. During this process, after the drugs dissolve, a white flocculent precipitate is formed. With continued stirring, the flocculent precipitate disappears and becomes a milky liquid, resulting in a mixed solution.

[0042] S3: Heat the water bath to 90℃, stir at 200 rpm for the first hour, then increase the stirring speed to 400 rpm at 5 rpm / min until the water is completely evaporated. Then, expose the obtained product to UV light; the UV intensity is 300 uw / cm. 2 Place it in a forced-air drying oven at 90-100℃ for 12-18 hours and dry it at room temperature to obtain the precursor.

[0043] S4: After grinding the precursor, it is placed in a tube furnace and heated to 600°C at a rate of 5°C / min under an argon atmosphere with a gas flow rate of 150 sccm. After reaching 800°C, the argon atmosphere is kept constant, and ammonia is introduced at a gas flow rate of 50 sccm. After holding at this temperature for 5 hours, the ammonia is turned off and the temperature is lowered to 200°C at a rate of 5°C / min. Then, it is allowed to cool naturally to room temperature to obtain porous hexagonal boron nitride nanofibers.

[0044] S5: Disperse 50 mg of PS-P2VP block copolymer in 10 ml of toluene solvent, seal and stir in the dark for 3-7 days until completely dissolved;

[0045] S6: Add H2PtCl6·6H2O to the above solution and continue to stir in the dark for 3 days to obtain a reverse micelle solution loaded with platinum salt;

[0046] S7: Add the porous hexagonal boron nitride nanofibers from step S4 to the above solution, and stir with a magnetic stirrer at room temperature for 36 hours to obtain the product;

[0047] S8: After drying the product, anneal it in air at 450℃ for 20 min to obtain a composite carrier of platinum nanoparticles and porous hexagonal boron nitride fibers.

[0048] The preparation method of this aquatic Trichomonas hydrophila and oligotrophosome compound inoculant includes inoculating the seed culture of aquatic Trichomonas hydrophila and oligotrophosomes into the culture medium at 1% v / v for enrichment culture, with a ratio of aquatic Trichomonas hydrophila and oligotrophosomes of 1:1, introducing sterile air into the tank during fermentation, stirring at 100 rpm, fermentation temperature at 30℃, fermentation time at 40 h, and collecting the culture medium as the microbial inoculant of denitrifying bacteria aquatic Trichomonas hydrophila and oligotrophosomes.

[0049] Each liter of the aforementioned culture medium contains 1.0g sodium bicarbonate, 0.5g ferrous sulfate, 0.1g potassium hydrogen phosphate, 0.5g potassium dihydrogen phosphate, 0.1g calcium chloride, 0.1g magnesium sulfate, 0.1g potassium nitrate, and 2ml of trace elements, wherein each liter of trace elements contains 0.1g zinc sulfate, 0.5g ferrous sulfate, 0.5g copper sulfate, 0.1g manganese chloride, 0.1g cobalt chloride, and 1.0g EDTA.

[0050] like Figure 1 As shown, the present invention also provides a method for preparing a wastewater treatment agent for treating nitrogen pollution, comprising:

[0051] The microcrystalline wax was heated in a water bath at 80°C until it was completely melted. During this process, it was stirred at 50 rpm for 5 minutes every 20 minutes. The platinum nanoparticles and porous hexagonal boron nitride fiber composite carrier prepared above were added during the third stirring.

[0052] Add the composite microbial agent of aquatic Trichomonas and Oligotrophus prepared as described above and nutrients to the completely melted solution, and stir at 50 rpm for 30 min to make the microbial agent and nutrients evenly distributed in the wax liquid and attached to the porous carrier. The nutrients are culture medium, biopolyester and diatomaceous earth. All materials are prepared into nutrient granules with slow-release effect through granulation process.

[0053] Finally, pour the mixture into the prepared mold and allow it to cool naturally to obtain the wastewater treatment agent.

[0054] Example 2:

[0055] A wastewater treatment agent for treating nitrogen pollution includes a composite carrier of platinum nanoparticles and porous hexagonal boron nitride fibers, and a composite bacterial agent of aquatic Trichomonas aquatilis and Oligotrophospora attached to the composite carrier, wherein Trichomonas aquatilis and Oligotrophospora are present.

[0056] The preparation method of this platinum nanoparticle-porous hexagonal boron nitride fiber composite carrier includes:

[0057] S1: Heat 150ml of deionized water to 65℃;

[0058] S2: Melamine and boric acid are added to the prepared deionized water in a mass ratio of 1.3:1 and stirred at a rate of 200 r / min. During this process, after the drugs dissolve, a white flocculent precipitate is formed. With continued stirring, the flocculent precipitate disappears and becomes a milky liquid, resulting in a mixed solution.

[0059] S3: Heat the water bath to 90℃, stir at 200 rpm for the first 1.5 hours, then increase the stirring speed to 400 rpm at 5 rpm / min until the water is completely evaporated. The resulting product is then subjected to UV light; the UV intensity is 4000 uw / cm. 2 The precursor was obtained by drying it in a forced-air drying oven at 95°C for 16 hours and then cooling it to room temperature.

[0060] S4: After grinding the precursor, it is placed in a tube furnace and heated to 700°C at a rate of 5°C / min under an argon atmosphere with a gas flow rate of 180 sccm. After reaching 800°C, the argon atmosphere is kept constant, and ammonia is introduced at a gas flow rate of 80 sccm. After holding at this temperature for 8 hours, the ammonia is turned off and the temperature is lowered to 250°C at a rate of 5°C / min. Then, it is allowed to cool naturally to room temperature to obtain porous hexagonal boron nitride nanofibers.

[0061] S5: Disperse 80 mg of PS-P2VP block copolymer in 15 ml of toluene solvent, and stir in the dark for 3-7 days until completely dissolved;

[0062] S6: Add H2PtCl6·6H2O to the above solution and continue to stir in the dark for 5 days to obtain a reverse micelle solution loaded with platinum salt.

[0063] S7: Add the porous hexagonal boron nitride nanofibers from step S4 to the above solution, and stir with a magnetic stirrer at room temperature for 50 h to obtain the product;

[0064] S8: After drying the product, anneal it in air at 500℃ for 40 min to obtain a composite carrier of platinum nanoparticles and porous hexagonal boron nitride fibers.

[0065] The preparation method of this aquatic Trichomonas hydrophila and oligotrophosome compound inoculant includes inoculating the seed culture of aquatic Trichomonas hydrophila and oligotrophosomes into the culture medium at 1% v / v for enrichment culture, mixing aquatic Trichomonas hydrophila and oligotrophosomes at a 1:1 ratio, introducing sterile air into the tank during fermentation, stirring at 200 rpm, fermenting at 35℃, fermenting for 50 h, and collecting the culture medium as the microbial inoculant of denitrifying bacteria aquatic Trichomonas hydrophila and oligotrophosomes.

[0066] Each liter of the aforementioned culture medium contains 1.5g sodium bicarbonate, 0.6g ferrous sulfate, 0.2g potassium hydrogen phosphate, 0.6g potassium dihydrogen phosphate, 0.15g calcium chloride, 0.15g magnesium sulfate, 0.2g potassium nitrate, and 3ml of trace elements, wherein each liter of trace elements contains 0.15g zinc sulfate, 0.6g ferrous sulfate, 0.6g copper sulfate, 0.15g manganese chloride, 0.15g cobalt chloride, and 1.3g EDTA.

[0067] like Figure 1 As shown, the present invention also provides a method for preparing a wastewater treatment agent for treating nitrogen pollution, comprising:

[0068] The microcrystalline wax was heated in a water bath at 85°C until it was completely melted. During this process, it was stirred at 80 rpm for 8 minutes every 20 minutes. When stirring for the third time, the platinum nanoparticles and porous hexagonal boron nitride fiber composite carrier prepared as described above were added.

[0069] Add the composite microbial agent of aquatic Trichomonas and Oligotrophus prepared as described above and nutrients to the completely melted solution, and stir at 80 rpm for 30 min to make the microbial agent and nutrients evenly distributed in the wax liquid and attached to the porous carrier. The nutrients are culture medium, biopolyester and diatomaceous earth. All materials are prepared into nutrient granules with slow-release effect through granulation process.

[0070] Finally, pour the mixture into the prepared mold and allow it to cool naturally to obtain the wastewater treatment agent.

[0071] Example 3:

[0072] A wastewater treatment agent for treating nitrogen pollution includes a composite carrier of platinum nanoparticles and porous hexagonal boron nitride fibers, and a composite bacterial agent of aquatic Trichomonas aquatilis and Oligotrophospora attached to the composite carrier, wherein Trichomonas aquatilis and Oligotrophospora are present.

[0073] The preparation method of this platinum nanoparticle-porous hexagonal boron nitride fiber composite carrier includes:

[0074] S1: Heat 200ml of deionized water to 70℃;

[0075] S2: Melamine and boric acid are added to the prepared deionized water in a mass ratio of 1.5:1 and stirred at a rate of 200 r / min. During this process, after the drugs dissolve, a white flocculent precipitate is formed. With continued stirring, the flocculent precipitate disappears and becomes a milky liquid, resulting in a mixed solution.

[0076] S3: Heat the water bath to 90℃ and stir at 200 rpm for the first 2 hours. Then, increase the stirring speed to 400 rpm at 5 rpm / min until the water is completely evaporated. Subsequently, expose the obtained product to ultraviolet light; the ultraviolet intensity is 8000 uw / cm. 2 The precursor was obtained by drying it in a forced-air drying oven at 100°C for 18 hours and then cooling it to room temperature.

[0077] S4: After grinding the precursor, it is placed in a tube furnace and heated to 800°C at a rate of 5°C / min under an argon atmosphere with a gas flow rate of 200 sccm. After reaching 800°C, the argon atmosphere is kept constant, and ammonia is introduced at a gas flow rate of 100 sccm. After holding at this temperature for 10 hours, the ammonia is turned off and the temperature is lowered to 300°C at a rate of 5°C / min. Then, it is allowed to cool naturally to room temperature to obtain porous hexagonal boron nitride nanofibers.

[0078] S5: Disperse 100 mg of PS-P2VP block copolymer in 20 ml of toluene solvent, and stir in the dark for 3-7 days until completely dissolved;

[0079] S6: Add H2PtCl6·6H2O to the above solution and continue to stir in the dark for 7 days to obtain a reverse micelle solution loaded with platinum salt;

[0080] S7: Add the porous hexagonal boron nitride nanofibers from step S4 to the above solution, and stir with a magnetic stirrer at room temperature for 72 hours to obtain the product;

[0081] S8: After drying the product, anneal it in air at 650°C for 60 min to obtain a composite carrier of platinum nanoparticles and porous hexagonal boron nitride fibers.

[0082] The preparation method of this aquatic Trichomonas hydrophila and oligotrophosome compound inoculant includes inoculating the seed culture of aquatic Trichomonas hydrophila and oligotrophosomes into the culture medium at 1% v / v for enrichment culture, mixing aquatic Trichomonas hydrophila and oligotrophosomes at a 1:1 ratio, introducing sterile air into the tank during fermentation, stirring at 300 rpm, fermenting at 40℃, fermenting for 60 h, and collecting the culture medium as the microbial inoculant of denitrifying bacteria aquatic Trichomonas hydrophila and oligotrophosomes.

[0083] Each liter of the aforementioned culture medium contains 2.0g sodium bicarbonate, 0.7g ferrous sulfate, 0.3g potassium hydrogen phosphate, 0.7g potassium dihydrogen phosphate, 0.2g calcium chloride, 0.2g magnesium sulfate, 0.3g potassium nitrate, and 4ml trace elements, of which each liter of trace elements contains 0.2g zinc sulfate, 0.7g ferrous sulfate, 0.7g copper sulfate, 0.2g manganese chloride, 0.2g cobalt chloride, and 1.5g EDTA.

[0084] like Figure 1As shown, the present invention also provides a method for preparing a wastewater treatment agent for treating nitrogen pollution, comprising:

[0085] The microcrystalline wax was heated in a water bath at 90°C until it was completely melted. During this process, it was stirred at 100 rpm for 10 minutes every 20 minutes. When stirring for the third time, the platinum nanoparticles and porous hexagonal boron nitride fiber composite carrier prepared as described above were added.

[0086] Add the composite microbial agent of aquatic tufted ...

[0087] Finally, pour the mixture into the prepared mold and allow it to cool naturally to obtain the wastewater treatment agent.

[0088] Comparative Example 1:

[0089] This comparative example is basically the same as Example 1, except that a single aquatic Trichomonas vaginalis is used as the microbial agent.

[0090] Comparative Example 2:

[0091] This comparative example is basically the same as Example 1, except that the porous carrier is porous hexagonal boron nitride fiber.

[0092] Comparative Example 3:

[0093] This comparative example is basically the same as Example 2, except that the microcrystalline wax is heated in a water bath at 85°C until completely melted, and then stirred at 80 rpm. Platinum nanoparticles and porous hexagonal boron nitride fiber composite carrier are added during stirring.

[0094] Comparative Example 4:

[0095] This comparative example is basically the same as Example 3, except that platinum nanoparticles and porous hexagonal boron nitride fiber composite carriers were added to the prepared aquatic tufted bacteria and oligotrophic bacteria composite agent, and the mixture was cultured in a shaker at room temperature for 24 hours and then filtered to obtain the wastewater treatment agent.

[0096] The application of this wastewater treatment agent in wastewater treatment is as follows: wastewater from a refining and chemical enterprise is selected, and its dissolved oxygen is adjusted to 0.2-0.5 mg / L and pH to 6.5-7.5. Seven wastewater samples of the same volume are prepared, and the wastewater treatment agent is added to the wastewater at a mass-volume ratio of 0.1 g: 1 L. The temperature is controlled at 20-35℃, and the mixture is stirred for 8-12 hours. The removal rates of total nitrogen and nitrate nitrogen in the wastewater are then tested and calculated. The results are shown in Table 1 below.

[0097] Table 1:

[0098]

[0099] As can be seen from the results in Table 1, the wastewater treatment agent prepared by the present invention has a good removal capacity for nitrogen in wastewater, and the removal rate of both can reach more than 97%. However, the nitrate nitrogen removal rate of the wastewater treatment agent prepared in the comparative example is the lowest at 45% and the highest at 50%, while the total nitrogen removal rate is only 63% at most, which is far lower than the removal effect of the wastewater treatment agent of the present invention.

[0100] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the methods and techniques disclosed above without departing from the scope of the present invention to create equivalent embodiments. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for preparing a wastewater treatment agent for treating nitrogen pollution, characterized in that: Includes the following steps: The microcrystalline wax was heated in a water bath at 80-90 ℃ until completely melted. During this process, it was stirred at 50-100 rpm for 5-10 minutes every 20 minutes. The porous carrier was added during the third stirring. Microbial agents and nutrients are added to the completely melted solution and stirred at 50-100 rpm for 30 minutes to ensure that the microbial agents and nutrients are evenly distributed in the wax liquid and adhered to the porous carrier. The nutrients are culture medium, biopolyester and diatomaceous earth. All materials are prepared into nutrient granules with a slow-release effect through granulation process. Finally, pour it into the prepared mold and let it cool naturally to obtain the wastewater treatment agent; The porous support is a composite support of platinum nanoparticles and porous hexagonal boron nitride fibers. The preparation method of the platinum nanoparticle and porous hexagonal boron nitride fiber composite carrier includes the following steps: S1: Heat 100-200ml of deionized water to 60-70℃; S2: Melamine and boric acid are added to the prepared deionized water in a mass ratio of 1-1.5:1 and stirred at a rate of 200 r / min. During this process, after the drugs dissolve, a white flocculent precipitate is formed. With continued stirring, the flocculent precipitate disappears and becomes a milky liquid, thus obtaining a mixed solution. S3: Heat the water bath to 90℃, stir at 200 rpm for the first 1-2 hours, then increase the stirring speed to 400 rpm at 5 rpm / min until the water is completely evaporated. Then, expose the obtained product to ultraviolet light with an intensity of 100-10000 μW / cm. 2 Place it in a forced-air drying oven at 90-100℃ for 12-18 hours and dry it at room temperature to obtain the precursor. S4: After grinding the precursor, place it in a tube furnace and heat it to 600-800℃ at a rate of 5℃ / min under an argon atmosphere with a gas flow rate of 150-200 sccm. After reaching 800℃, keep the argon gas constant and introduce ammonia gas at a flow rate of 50-100 sccm. After holding at this temperature for 5-10 h, turn off the ammonia gas and cool it down to 200-300℃ at a rate of 5℃ / min. Then, allow it to cool naturally to room temperature to obtain porous hexagonal boron nitride nanofibers. S5: Disperse 50-100 mg of PS-P2VP block copolymer in 10-20 ml of toluene solvent, and stir in the dark for 3-7 days until completely dissolved; S6: Add H2PtCl6∙6H2O to the above solution, and continue to stir in the dark for 3-7 days to obtain a reverse micelle solution loaded with platinum salt; S7: Add the porous hexagonal boron nitride nanofibers from step S4 to the above solution, and stir with a magnetic stirrer at room temperature for 36-72 h to obtain the product; S8: After drying the product, anneal it in air at 450-650 ℃ for 20-60 min to obtain a composite carrier of platinum nanoparticles and porous hexagonal boron nitride fibers. The microbial inoculant includes facultative anaerobic autotrophic denitrifying bacteria, the autotrophic denitrifying bacteria including *Trichophyton aquatilis* and *Oligotroph ...

2. The method for preparing a wastewater treatment agent for treating nitrogen pollution according to claim 1, characterized in that: Each liter of the culture medium contains 1.0-2.0 g of sodium bicarbonate, 0.5-0.7 g of ferrous sulfate, 0.1-0.3 g of potassium hydrogen phosphate, 0.5-0.7 g of potassium dihydrogen phosphate, 0.1-0.2 g of calcium chloride, 0.1-0.2 g of magnesium sulfate, 0.1-0.3 g of potassium nitrate, and 2-4 ml of trace elements.

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