Denitrification filter material synthesis process for inhibiting generation of hydrogen sulfide

Abstract

The invention discloses a process for synthesizing a denitrification filter material for inhibiting generation of hydrogen sulfide, belongs to the technical field of environment-friendly materials, and particularly relates to a denitrification filter material which comprises a sulfur matrix, a molten dispersion dispersed in the sulfur matrix and a functional material, the amount of the molten dispersion is 20-50 wt% of the sulfur matrix, and the amount of the functional material is 0.1-8 wt% of the sulfur matrix. The molten dispersion is formed by compounding an oxide complex and a dispersion material, the oxide complex comprises cerium oxide and iron oxide, and the dispersion material comprises ethylene bis stearamide and / or polyesteramide and / or polyamide etherate. The invention aims to provide a denitrification filter material synthesis process for inhibiting generation of hydrogen sulfide, which has a good denitrification effect, adsorbs organic carbon and can be used for sewage treatment and wastewater purification.

Description

Technical Field

[0001] The present invention belongs to the technical field of environmental protection materials, and particularly relates to a synthesis process of a denitrification filter material for inhibiting hydrogen sulfide generation. Background Art

[0002] The existing advanced denitrification technology mainly relies on heterotrophic denitrification, which requires a large amount of organic carbon sources. At the same time, the large addition of carbon sources will lead to situations such as carbon source breakthrough and excessive sludge production, causing secondary pollution to the environment. Therefore, the new sulfur autotrophic denitrification process, as an alternative to heterotrophic denitrification, has gradually received attention.

[0003] The sulfur autotrophic denitrification process refers to a denitrification process in which, under the action of autotrophic denitrifying bacteria, using inorganic carbon sources, with reducing sulfides (such as sodium sulfide, sodium thiosulfate, elemental sulfur, pyrite, etc.) as electron donors, and at the same time using nitrate nitrogen or nitrite nitrogen in sewage as electron acceptors, ultimately reducing NOx-N to nitrogen gas.

[0004] In the sulfur autotrophic denitrification process with elemental sulfur as the electron donor, the elemental sulfur filler is the core material of this process. On the one hand, compared with the heterotrophic denitrification process using organic carbon sources as electron donors, elemental sulfur, as a relatively inexpensive industrial product, has a lower price than conventional organic carbon sources, which can significantly reduce the operating cost of advanced denitrification. On the other hand, the sulfur autotrophic denitrification process does not use organic carbon sources, has no risk of carbon source breakthrough, and does not produce a large amount of excess sludge, which greatly reduces the potential risks of municipal wastewater treatment plants. Therefore, it has been widely applied in recent years. However, sulfur autotrophic denitrification is a process of producing acid and consuming alkalinity. During the operation process, the pH value of the water shows a downward trend; and the optimal pH range for elemental sulfur autotrophic denitrification is 6.8 - 8.2; some scholars have found that without adding external alkalinity, the sulfur autotrophic denitrification reaction will cause the pH value to be below 5.5, which seriously affects the progress of the denitrification reaction. Moreover, the insolubility of elemental sulfur in water further affects the utilization rate of sulfur by microorganisms, resulting in the difficulty of sulfur autotrophic denitrification to be applied to high-load advanced denitrification treatment.

[0005] CN116332343A discloses a sulfur autotrophic denitrification sulfur-based magnetic filler and its preparation method and application. The sulfur-based magnetic filler of this invention includes sulfur-containing sludge, biomass, slow-release inorganic carbon source, alkaline substances, metal loading, magnetic materials, binders, etc., and the formula is complex. CN113697950A discloses a sulfur autotrophic denitrification substrate for biological denitrification and its usage method. The buffer used therein is calcium carbonate or magnesium carbonate, and the released calcium and magnesium ions will recombine with the alkalinity in water to form precipitates, which will further inhibit the progress of autotrophic denitrification reaction. The sulfur autotrophic filler provided by CN116143281A includes a porous carrier and elemental sulfur; the elemental sulfur is loaded on the porous carrier; the porous carrier is mainly prepared from nano-calcium carbonate, binder and pore-forming agent. However, when nano-calcium carbonate is used as the component providing alkalinity and calcium carbonate deposits are formed again on the surface, it will have an adverse effect on the utilization of sulfur by microorganisms. Summary of the Invention

[0006] The purpose of the present invention is to provide a denitrification filter synthesis process with good denitrification effect, capable of adsorbing organic carbon, and can be used for sewage treatment and wastewater purification, which can inhibit the generation of hydrogen sulfide.

[0007] The technical solution adopted by the present invention to achieve the above purpose is as follows: A denitrification filter, comprising: a sulfur matrix, a molten dispersion and a functional material dispersed in the sulfur matrix; the amount of the molten dispersion is 20-50 wt% of the sulfur matrix, and the amount of the functional material is 0.1-8 wt% of the sulfur matrix. Under anoxic or anaerobic conditions, sulfur-oxidizing bacteria use reduced sulfur as an electron donor, inorganic carbon as a carbon source, and nitrate nitrogen as an electron acceptor, obtain energy by oxidizing reduced sulfur, convert sulfur into sulfate radicals, inhibit the generation of hydrogen sulfide, and reduce the content of hydrogen sulfide. By introducing an oxide complex composed of cerium oxide and iron oxide into the denitrification filter, the denitrification effect under the action of the denitrification filter and activated sludge is improved, and the generation of hydrogen sulfide is effectively inhibited and the water treatment effect is improved.

[0008] Preferably, the molten dispersion is composed of a composite of an oxide complex and a dispersing material. The oxide complex includes cerium oxide and iron oxide, and the dispersing material includes ethylene bisstearamide and / or polyester amide and / or polyamide ether. In the present invention, a molten dispersion is obtained by compounding the oxide complex and the dispersing material. Then, the oxide complex is a cerium-iron composite oxide coupled with a silane coupling agent. Then, the molten dispersion and the functional material are dispersed in a sulfur melt having a porous sulfur matrix to form a denitrification filter medium. Among them, the use of ethylene bisstearamide and / or polyester amide and / or polyamide ether forms a sulfur-based filter medium with internal pores and a rough surface during compounding. Under the action of the structure of ethylene bisstearamide and / or polyester amide and / or polyamide ether, the oxide complex coupled with the silane coupling agent, the dispersing material, and the porous sulfur matrix, the effect of inhibiting hydrogen sulfide generation is improved, the removal of nitrate nitrogen in sewage is improved, and the removal of total organic carbon in sewage is improved.

[0009] More preferably, the oxide complex is a cerium-iron oxidation conjugate. The cerium-iron oxidation conjugate is obtained by mixing ammonium cerium nitrate, iron nitrate, and citric acid in a solution, stirring until a gel is formed, then performing a calcination treatment, and then mixing with a silane coupling solution.

[0010] Preferably, the functional material includes hydrogenated castor oil.

[0011] The present invention discloses a synthesis process of a denitrification filter medium, including: melting sulfur and then adding a nucleating agent, then adding a molten dispersion and a functional material, performing low-speed shear mixing to form a composite melt, and rapidly solidifying after high-pressure spraying to obtain a sulfur-based filter medium; the usage amount of the molten dispersion is 20-50 wt% of sulfur, and the usage amount of the functional material is 0.1-8 wt% of sulfur.

[0012] Preferably, the preparation of the molten dispersion includes a cerium-iron oxidation conjugate.

[0013] Preferably, in the preparation of the cerium-iron oxidation conjugate, ammonium cerium nitrate and iron nitrate are added to water and mixed, then citric acid is added, and stirred at 70-90 °C until a gel is formed, and calcined at 500-600 °C for 1-4 h under nitrogen protection to obtain a cerium-iron composite oxide. The cerium-iron composite oxide is added to a silane coupling solution to obtain a cerium-iron oxidation conjugate.

[0014] More preferably, in the preparation of the cerium-iron oxidation conjugate, ammonium cerium nitrate and iron nitrate are mixed in a molar ratio of cerium:iron of 1:1-4.

[0015] More preferably, in the preparation of the cerium-iron oxidation conjugate, the amount of ammonium cerium nitrate added to water is 0.1-0.25 mol / L More preferably, in the preparation of the cerium-iron oxide conjugate, the molar amount of citric acid used is 200-600% of the molar amount of cerium ammonium nitrate used.

[0016] More preferably, in the preparation of the cerium-iron oxide coupling, the silane coupling solution is prepared by mixing KH550 and ethanol, the content of KH550 in the silane coupling solution is 0.5-2wt%, and the amount of the silane coupling solution used is 60-100wt% of the cerium-iron composite oxide.

[0017] Preferably, in the preparation of the molten dispersion, the dispersed material is melted at 100-150° C. under nitrogen protection, and then the cerium-iron oxide conjugate is added and stirred for 10-60 minutes, and then the mixture is dried and crushed to obtain an oxide-coated molten dispersion.

[0018] More preferably, in the preparation of the molten dispersion, the dispersing material comprises ethylene bisstearamide, and the amount of the cerium iron oxide conjugate used is 60-300wt% of the ethylene bisstearamide. More preferably, in the preparation of the molten dispersion, the dispersing material comprises ethylene bisstearamide and polyamide etherate, the polyamide etherate is used in an amount of 10-60wt% of ethylene bisstearamide, and the cerium iron oxide conjugate is used in an amount of 60-300wt% of ethylene bisstearamide.

[0019] More preferably, in the preparation of the molten dispersion, the pulverized product is passed through a 80-100 mesh sieve.

[0020] Preferably, the preparation of the polyamide etherate comprises the preparation of a morpholine derivative.

[0021] Preferably, in the preparation of the morpholine derivative, 5-hydroxytryptophan is mixed with tetrahydrofuran, triethylamine and chloroacetyl chloride are added at 0-10°C and mixed, and then stirred at 20-40°C for 3-12h. After the reaction is completed, the tetrahydrofuran is dried by rotary evaporation, dichloromethane is added to dissolve, saturated sodium chloride solution is washed, dried, and dichloromethane is vacuum-evacuated to obtain an intermediate product; the intermediate product and sodium bicarbonate are added to N,N-dimethylformamide, stirred at 40-90°C for 6-24h, filtered, N,N-dimethylformamide is removed by vacuum distillation, dichloromethane is added to dissolve, saturated sodium chloride solution is washed, dried, dichloromethane is removed by rotary evaporation, and column chromatography is eluted to obtain a morpholine derivative.

[0022] More preferably, in the preparation of the morpholine derivative, the amount of 5-hydroxytryptophan used is 2-6 wt % of tetrahydrofuran. More preferably, in the preparation of the morpholine derivative, the amount of triethylamine used is 80-120 wt % of 5-hydroxytryptophan.

[0023] More preferably, in the preparation of the morpholine derivative, the amount of chloroacetyl chloride used is 60-100 wt % of 5-hydroxytryptophan.

[0024] More preferably, in the preparation of the morpholine derivative, the usage amount of sodium bicarbonate is 200 - 400 wt% of tryptophan.

[0025] More preferably, in the preparation of the morpholine derivative, the usage amount of N,N - dimethylformamide is 800 - 1200 wt% of tryptophan.

[0026] Preferably, in the preparation of the polyamide ether compound, the morpholine derivative and caprolactone are added into chloroform, then a catalyst is added, and polymerization is carried out at 20 - 40 °C for 2 - 12 h. After the reaction is completed, anhydrous ether is added to precipitate the solid, and vacuum drying is carried out to obtain the polyamide ether compound.

[0027] More preferably, in the preparation of the polyamide ether compound, the usage amount of the morpholine derivative is 10 - 40 wt% of chloroform More preferably, in the preparation of the polyamide ether compound, the usage amount of caprolactone is 100 - 1000 wt% of the morpholine derivative.

[0028] More preferably, in the preparation of the polyamide ether compound, the catalyst is DBU, and the usage amount of the catalyst is 0.1 - 2 wt% of the morpholine derivative.

[0029] Preferably, the nucleating agent is molybdenum disulfide.

[0030] Preferably, the rotation speed of low - speed shearing is 600 - 1000 rpm, and the mixing time of low - speed shearing is 10 - 60 min.

[0031] Preferably, the temperature of the composite melt during high - pressure spraying is 110 - 140 °C.

[0032] Preferably, in the preparation of the molten dispersion, the dispersion material is melted and then added to the oxide composite for mixing, and after drying and pulverizing, the molten dispersion is obtained.

[0033] Preferably, in the preparation of the sulfur - based filter material, sulfur is melted at 120 - 150 °C, then molybdenum disulfide is added and mixed evenly, then the molten dispersion and the functional material are added, and low - speed shearing and mixing are carried out at 600 - 1000 rpm for 10 - 60 min to form a composite sulfur melt. After cooling to 110 - 140 °C, high - pressure spraying is carried out to form droplets, and the droplets are solidified in water at 0 - 10 °C to obtain the sulfur - based filter material.

[0034] More preferably, in the preparation of the sulfur - based filter material, the usage amount of molybdenum disulfide is 0.2 - 1 wt% of sulfur.

[0035] More preferably, in the preparation of the sulfur - based filter material, the usage amount of the molten dispersion is 20 - 50 wt% of sulfur.

[0036] More preferably, in the preparation of the sulfur-based filter material, the functional material is hydrogenated castor oil, and the amount of hydrogenated castor oil used is 1-5wt% of the sulfur.

[0037] More preferably, in the preparation of the sulfur-based filter material, the functional material also includes polymethacrylamide propyl trimethyl ammonium methyl sulfate, and the amount of polymethacrylamide propyl trimethyl ammonium methyl sulfate used is 0.1-3wt% of sulfur. In the present invention, when preparing the sulfur-based filter material, polymethacrylamide propyl trimethyl ammonium methyl sulfate can also be added to the functional material, and the polymethacrylamide propyl trimethyl ammonium methyl sulfate, under the action of ferrocerium oxide coupling and dispersing material, can further improve the effect of inhibiting the generation of hydrogen sulfide, improve the removal of nitric nitrogen in sewage, and improve the removal of total organic carbon in sewage.

[0038] More preferably, in the preparation of the sulfur-based filter material, the particle size of the sulfur-based filter material is 2-3 mm.

[0039] The invention discloses application of the above-mentioned denitrification filter material in sewage treatment and / or wastewater purification.

[0040] The invention adopts the method of mixing ammonium cerium nitrate, ferric nitrate and citric acid in a solution, stirring until a gel is formed, calcining the mixture, and then mixing the mixture with a silane coupling solution to obtain a ferrocerium oxide coupling; then melting ethylene bisstearamide and mixing the mixture with the ferrocerium oxide coupling, drying and crushing the mixture to obtain a ferrocerium oxide coupling-coated molten dispersion; finally, sulfur is used as a matrix, molybdenum disulfide is added after the sulfur is melted, and the molybdenum disulfide is used as a nucleating agent to form a porous sulfur matrix; then the molten dispersion and the functional material are added, and the mixture is sprayed under high pressure and rapidly solidified in cold water to form a sulfur-based filter material; the invention adopts the method of preparing a molten dispersion and a functional material, and a molten dispersion is prepared by the method of preparing a molten dispersion. When preparing the polyamide ether, a polyamide ether can be added and used together with ethylene bis stearamide. The polyamide ether is firstly reacted by 5-hydroxytryptophan and chloroacetyl chloride to generate an intermediate, and then the intermediate is cyclized to form a morpholine derivative. The morpholine derivative and caprolactone are ring-opening polymerized under the action of a catalyst to form a polyamide ether with different block structures; and finally used to prepare a sulfur-based filter material, so it has the following beneficial effects: it has a good removal effect on the total organic carbon in the sewage, and it can be combined with activated sludge to better remove nitrate nitrogen, which can be used for sewage treatment and wastewater purification, and in the case of sulfur autotrophy, it can inhibit the generation of hydrogen sulfide. Therefore, the present invention is a denitrification filter material synthesis process with good denitrification effect, adsorption of organic carbon, and inhibition of hydrogen sulfide generation that can be used for sewage treatment and wastewater purification. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is the SEM image of sulfur-based filter material.

[0042] Figure 2 This is the total organic carbon removal rate diagram.

[0043] Figure 3 It is a graph of nitrate nitrogen removal rate. Specific implementation manner

[0044] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0045] First, the concepts involved in the present application will be described in conjunction with the accompanying drawings. It should be noted here that the following descriptions of each concept are only for making the content of the present application easier to understand, and do not represent a limitation on the protection scope of the present application; at the same time, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0046] Example 1: A synthesis process of a denitrification filter material for inhibiting hydrogen sulfide generation Preparation of cerium-iron oxide conjugate: Ammonium cerium nitrate and ferric nitrate are added to water and mixed, then citric acid is added, and stirred at 80 °C until gel formation occurs, and calcined at 550 °C for 2 h under nitrogen protection to obtain cerium-iron composite oxide. The cerium-iron composite oxide is added to the silane coupling solution to obtain a cerium-iron oxide conjugate. Ammonium cerium nitrate and ferric nitrate are mixed in a molar ratio of cerium: iron of 1:2. The amount of ammonium cerium nitrate added to water is 0.2 mol / L, and the molar amount of citric acid used is 360% of the molar amount of ammonium cerium nitrate used. The silane coupling solution is composed of KH550 and ethanol, and the content of KH550 in the silane coupling solution is 1 wt%, and the usage amount of the silane coupling solution is 80 wt% of the cerium-iron composite oxide.

[0047] Preparation of molten dispersion: Under nitrogen protection, ethylene bisstearamide is melted at 120 °C, then the cerium-iron oxide conjugate is added and stirred and mixed for 30 min, dried and pulverized to obtain an oxide-coated molten dispersion. The usage amount of the cerium-iron oxide conjugate is 100 wt% of ethylene bisstearamide. After drying and pulverizing, it is sieved through a 100-mesh sieve before use.

[0048] Preparation of sulfur-based filter material: melt sulfur at 130°C, then add molybdenum disulfide and mix evenly, then add molten dispersion and functional material, and mix at low speed shear at 800rpm for 30 minutes to form a composite sulfur melt, cool to 115°C, spray into droplets at high pressure, and solidify the droplets in water at 5°C to obtain sulfur-based filter material. The amount of molybdenum disulfide used is 0.5wt% of sulfur, the amount of molten dispersion used is 30wt% of sulfur, the functional material is hydrogenated castor oil, and the amount of hydrogenated castor oil used is 3wt% of sulfur. The particle size of the sulfur-based filter material is 2-3mm.

[0049] Example 2: A synthesis process for a denitrification filter material for inhibiting the generation of hydrogen sulfide The difference between this embodiment and embodiment 1 lies in the preparation of the molten dispersion. Polyamide etherification is added in the preparation of the molten dispersion.

[0050] Preparation of morpholine derivatives: 5-hydroxytryptophan is mixed with tetrahydrofuran, triethylamine and chloroacetyl chloride are added at 5°C, and then stirred at 30°C for 6 hours. After the reaction is completed, the tetrahydrofuran is dried by rotary evaporation, dichloromethane is added to dissolve, saturated sodium chloride solution is washed, dried, and dichloromethane is vacuum-evacuated to obtain an intermediate product; the intermediate product and sodium bicarbonate are added to N,N-dimethylformamide, stirred at 60°C for 12 hours, filtered, N,N-dimethylformamide is removed by reduced pressure distillation, dichloromethane is added to dissolve, saturated sodium chloride solution is washed, dried, dichloromethane is removed by rotary evaporation, and column chromatography is eluted to obtain a morpholine derivative. The usage of 5-hydroxytryptophan is 4wt% of tetrahydrofuran, the usage of triethylamine is 100wt% of 5-hydroxytryptophan, the usage of chloroacetyl chloride is 80wt% of 5-hydroxytryptophan, the usage of sodium bicarbonate is 300wt% of 5-hydroxytryptophan, and the usage of N,N-dimethylformamide is 1000wt% of 5-hydroxytryptophan.

[0051] Preparation of polyamide ether: morpholine derivative and caprolactone are added to chloroform, and then a catalyst is added, and polymerization is carried out at 30°C for 6 hours. After the reaction is completed, anhydrous ether is added to precipitate the solid, and vacuum drying is performed to obtain a polyamide ether. The amount of morpholine derivative used is 30wt% of chloroform, the amount of caprolactone used is 400wt% of the morpholine derivative, and the catalyst is DBU, and the amount of the catalyst used is 1wt% of the morpholine derivative.

[0052] Preparation of molten dispersion: Ethylene bis stearamide and polyamide ether are melted at 120°C under nitrogen protection, and then cerium iron oxide conjugate is added and stirred for 30 minutes, dried and crushed to obtain an oxide-coated molten dispersion. The amount of polyamide ether is 20wt% of ethylene bis stearamide, and the amount of cerium iron oxide conjugate is 100wt% of ethylene bis stearamide.

[0053] Example 3: Synthesis Process of a Denitrification Filter Media for Inhibiting Hydrogen Sulfide Generation This example is different from Example 2 in the preparation of the molten dispersion.

[0054] Preparation of the molten dispersion: Under nitrogen protection, ethylene bisstearamide and polyamide ether were melted at 120°C, then cerium-iron oxidation conjugate was added and stirred for 30 minutes, dried and crushed to obtain an oxide-coated molten dispersion. The usage amount of polyamide ether is 30 wt% of ethylene bisstearamide, and the usage amount of cerium-iron oxidation conjugate is 100 wt% of ethylene bisstearamide.

[0055] Example 4: Synthesis Process of a Denitrification Filter Media for Inhibiting Hydrogen Sulfide Generation This example is different from Example 3 in the preparation of the sulfur-based filter media.

[0056] Preparation of the sulfur-based filter media: Sulfur was melted at 130°C, then molybdenum disulfide was added and mixed evenly, then the molten dispersion and functional materials were added, and low-speed shear mixing was carried out at 800 rpm for 30 minutes to form a composite sulfur melt. After cooling to 115°C, it was atomized into droplets by high-pressure spraying, and the droplets were solidified in water at 5°C to obtain the sulfur-based filter media. The usage amount of molybdenum disulfide is 0.5 wt% of sulfur, the usage amount of the molten dispersion is 30 wt% of sulfur, the functional materials are hydrogenated castor oil and polyacrylamide propyltrimethylammonium methyl sulfate, the usage amount of hydrogenated castor oil is 3 wt% of sulfur, and the usage amount of polyacrylamide propyltrimethylammonium methyl sulfate is 0.9 wt% of sulfur.

[0057] Example 5: Synthesis Process of a Denitrification Filter Media for Inhibiting Hydrogen Sulfide Generation This example is different from Example 4 in the preparation of the sulfur-based filter media.

[0058] Preparation of the sulfur-based filter media: Sulfur was melted at 130°C, then molybdenum disulfide was added and mixed evenly, then the molten dispersion and functional materials were added, and low-speed shear mixing was carried out at 800 rpm for 30 minutes to form a composite sulfur melt. After cooling to 115°C, it was atomized into droplets by high-pressure spraying, and the droplets were solidified in water at 5°C to obtain the sulfur-based filter media. The usage amount of molybdenum disulfide is 0.5 wt% of sulfur, the usage amount of the molten dispersion is 30 wt% of sulfur, the functional materials are hydrogenated castor oil and polyacrylamide propyltrimethylammonium methyl sulfate, the usage amount of hydrogenated castor oil is 3 wt% of sulfur, and the usage amount of polyacrylamide propyltrimethylammonium methyl sulfate is 2.1 wt% of sulfur.

[0059] Comparative Example 1: Synthesis Process of a Denitrification Filter Media for Inhibiting Hydrogen Sulfide Generation This comparative example is different from Example 2 in the preparation of the molten dispersion.

[0060] Preparation of the molten dispersion: Under nitrogen protection, ethylene bisstearamide and polyamide ether were melted at 120 °C, then cerium iron oxide conjugate was added and stirred for 30 min, dried and pulverized to obtain an oxide-coated molten dispersion. The usage amount of polyamide ether was 5 wt% of ethylene bisstearamide, and the usage amount of cerium iron oxide conjugate was 100 wt% of ethylene bisstearamide.

[0061] Comparative Example 2: A synthesis process of a denitrification filter material for inhibiting hydrogen sulfide generation This comparative example is different from Example 4 in the preparation of the molten dispersion.

[0062] Preparation of the molten dispersion: Under nitrogen protection, ethylene bisstearamide was melted at 120 °C, then cerium iron oxide conjugate was added and stirred for 30 min, dried and pulverized to obtain an oxide-coated molten dispersion. The usage amount of cerium iron oxide conjugate was 100 wt% of ethylene bisstearamide.

[0063] Test example: In the present invention, scanning electron microscopy was used to characterize the surface morphology of the sulfur-based filter material prepared in Example 2, and the results are as Figure 1 shown. There are small holes and small fragments on the surface of the sulfur-based filter material. The holes and rough surface increase the specific surface area of the sulfur-based filter material, providing good conditions for the attachment and growth of denitrifying bacteria. The porous structure inside the sulfur-based filter material is beneficial for microorganisms to fully utilize the electron donors therein, improving the denitrification efficiency.

[0064] Simulated sewage: The total nitrogen content was 0.37 g / L, the total phosphorus content was 0.025 g / L, and the total organic carbon content was 0.1 g / L. The total nitrogen included 0.35 g / L potassium nitrate and 0.02 g / L ammonium chloride. The total phosphorus included potassium dihydrogen phosphate.

[0065] 300 mL of simulated sewage and 8 g of sulfur-based filter material were mixed, sealed and oscillated at 30 °C for 5 d. After the cultivation was completed, it was filtered through a 0.45 μm filter membrane, and the nitrate nitrogen content was detected. It was found that the adsorption and removal effect of the sulfur-based filter material on nitrate nitrogen in the simulated sewage was weak, indicating that even if the sulfur-based filter material could adsorb nitrogen-containing molecules, it was easy to desorb.

[0066] After the sewage was treated as described above in the present invention, the total organic carbon content in the sewage was detected, and the total organic carbon removal rate was calculated. The results are as Figure 2As shown in the figure, where S1 is Example 1, S2 is Example 2, S3 is Example 3, S4 is Example 4, S5 is Example 5, D1 is Comparative Example 1, and D2 is Comparative Example 2. In the present invention, ammonium cerium nitrate, iron nitrate and citric acid are mixed in a solution, stirred until a gel is formed and then calcined, and then mixed with a silane coupling solution to obtain a cerium-iron oxide conjugate; then ethylene bisstearamide is melted and mixed with the cerium-iron oxide conjugate, dried and pulverized to obtain a molten dispersion coated with the cerium-iron oxide conjugate. Finally, sulfur is used as the matrix, molybdenum disulfide is added after sulfur is melted, and molybdenum disulfide is used as a nucleating agent to form a porous sulfur matrix, and then the molten dispersion and functional materials are added, and high-pressure spraying and rapid solidification in cold water are carried out to form a sulfur-based filter material. The sulfur-based filter material prepared by the present invention can adsorb organic carbon in sewage; when preparing the molten dispersion in the present invention, polyamide ether can be added and used together with ethylene bisstearamide. Polyamide ether is first prepared by reacting 5-hydroxytryptophan with chloroacetyl chloride to form an intermediate, and then the intermediate is cyclized to form a morpholine derivative. The morpholine derivative and ε-caprolactone are ring-opening polymerized under the action of a catalyst to form polyamide ether with different block structures; when polyamide ether and ethylene bisstearamide are mixed and used together, after the molten dispersion is prepared, the sulfur-based filter material is prepared. Under the action of the porous sulfur matrix, the molten dispersion formed by polyamide ether and ethylene bisstearamide, and the functional materials, the obtained sulfur-based filter material has a better adsorption and removal effect on organic carbon. When the amount of polyamide ether used is increased, the sulfur-based filter material has a stronger adsorption and removal effect on organic carbon; in addition to hydrogenated castor oil, poly(methacryloylpropyltrimethylammonium methyl sulfate) can also be used as the functional material in the present invention. When hydrogenated castor oil and poly(methacryloylpropyltrimethylammonium methyl sulfate) are used in the functional material, and polyamide ether and ethylene bisstearamide are used in the preparation of the molten dispersion, in the coexistence of the porous sulfur matrix and the molten dispersion coated with the cerium-iron oxide conjugate, the adsorption and removal effect of the obtained sulfur-based filter material on organic carbon is further improved.

[0067] Take 300 mL of nitrogen-containing simulated sewage and 100 mL of activated sludge, mix them, and then add 8 g of the sulfur-based filter material. Ensure an anaerobic environment under a nitrogen atmosphere, and shake and culture at 30 °C for 5 days. After the culture is completed, filter with a 0.45 μm filter membrane to detect the ammonium nitrogen content in the sewage. In the test of the present invention, the change in ammonium nitrogen content is not significant, indicating that in the water treatment of the sulfur-based filter material and activated sludge of the present invention, nitrate nitrogen utilization will generate ammonium nitrogen, but at the same time, ammonium nitrogen will be utilized and consumed by microorganisms. Therefore, the change in ammonia nitrogen content is not significant; detect the nitrate nitrogen content in the sewage, and calculate the nitrate nitrogen removal rate relative to the initial nitrate nitrogen content of the nitrogen-containing simulated sewage. The results are as Figure 3As shown, where S1 is Example 1, S2 is Example 2, S3 is Example 3, S4 is Example 4, S5 is Example 5, D1 is Comparative Example 1, and D2 is Comparative Example 2. In the present invention, ammonium cerium nitrate, iron nitrate and citric acid are mixed in a solution, stirred until a gel is formed and then calcined, and then mixed with a silane coupling solution to obtain a cerium-iron oxide conjugate; then ethylene bisstearamide is melted and mixed with the cerium-iron oxide conjugate, dried and pulverized to obtain a molten dispersion coated with the cerium-iron oxide conjugate. Finally, sulfur is used as the matrix, molybdenum disulfide is added after sulfur is melted, and molybdenum disulfide is used as a nucleating agent to form a porous sulfur matrix, and then the molten dispersion and the functional material are added, and high-pressure spraying and rapid curing in cold water are carried out to form a sulfur-based filter material. The sulfur-based filter material prepared by the present invention can remove nitrate nitrogen in sewage under the action of activated sludge; when preparing the molten dispersion in the present invention, polyamide ether can be added and used together with ethylene bisstearamide. Polyamide ether is first formed by reacting 5-hydroxytryptophan with chloroacetyl chloride to form an intermediate, and then the intermediate is cyclized to form a morpholine derivative, and the morpholine derivative and ε-caprolactone are ring-opening polymerized under the action of a catalyst to form polyamide ether with different block structures; when polyamide ether and ethylene bisstearamide are used together, after the molten dispersion is prepared, the sulfur-based filter material is prepared. Under the action of the porous sulfur matrix, the molten dispersion formed by polyamide ether and ethylene bisstearamide, and the functional material, the obtained sulfur-based filter material has a better nitrate nitrogen removal effect under the action of activated sludge. When the dosage of polyamide ether in the present invention is too low, the nitrate nitrogen removal effect of the obtained sulfur-based filter material under the action of activated sludge is not significantly enhanced, that is, within a certain range of the dosage of polyamide ether, the nitrate nitrogen removal effect of the obtained sulfur-based filter material under the action of activated sludge has an enhancing effect; when the dosage of polyamide ether is increased, the nitrate nitrogen removal effect of the obtained sulfur-based filter material under the action of activated sludge is stronger; in addition to using hydrogenated castor oil, the functional material in the present invention can also use poly(methacrylamide propyltrimethylammonium methyl sulfate). When hydrogenated castor oil and poly(methacrylamide propyltrimethylammonium methyl sulfate) are used in the functional material, and polyamide ether and ethylene bisstearamide are used in the preparation of the molten dispersion, in the coexistence of the porous sulfur matrix and the molten dispersion coated with the cerium-iron oxide conjugate, the nitrate nitrogen removal effect of the obtained sulfur-based filter material under the action of activated sludge is further improved. In the present invention, the adsorption effect of the sulfur-based filter material on nitrate nitrogen is not good, and after adding activated sludge, the nitrate nitrogen removal effect is enhanced, indicating that activated sludge is the key factor for removing nitrate nitrogen, but the composition and structure of the sulfur-based filter material can strengthen the performance of activated sludge and improve the nitrate nitrogen removal effect of activated sludge.

[0068] The above-described embodiments and / or implementation manners are only used to illustrate the preferred embodiments and / or implementation manners for implementing the technology of the present invention, and do not impose any formal restrictions on the implementation manners of the technology of the present invention. Any person skilled in the art, without departing from the scope of the technical means disclosed in the content of the present invention, may make some modifications or changes to other equivalent embodiments, but should still be regarded as the same technology or embodiment as the present invention in essence.

[0069] Specific examples are used in this article to elaborate on the principles and implementation manners of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea. The above are only the preferred implementation manners of the present application. It should be noted that due to the limited nature of language expression and the objectively infinite specific structures, for those of ordinary skill in the art, without departing from the principles of the present application, several improvements, refinements or changes can also be made, or the above technical features can be combined in an appropriate manner; these improvements, refinements, changes or combinations, or directly applying the concept and technical solution of the invention to other occasions without improvement, should all be regarded as the protection scope of the present application.

Claims

1. A denitrification filter medium, comprising: A sulfur matrix, a molten dispersion and a functional material dispersed in the sulfur matrix; the amount of the molten dispersion is 20-50wt% of the sulfur matrix, and the amount of the functional material is 0.1-8wt% of the sulfur matrix.

2. The denitrification filter medium according to claim 1, wherein: The molten dispersion is composed of an oxide complex and a dispersion material. The oxide complex includes cerium oxide and iron oxide. The dispersion material includes ethylene bisstearamide and / or polyester amide and / or polyamide ether.

3. The denitrification filter medium according to claim 2, characterized in that: The oxide complex is a cerium-iron oxide coupling, which is prepared by mixing ammonium cerium nitrate, ferric nitrate and citric acid in a solution, stirring until a gel is formed, calcining the mixture, and then mixing the mixture with a silane coupling solution to obtain the cerium-iron oxide coupling.

4. The denitrification filter medium according to claim 1, wherein: The functional material includes hydrogenated castor oil.

5. A synthesis process of denitrification filter media, comprising: After sulfur is melted, a nucleating agent is added, and then a molten dispersion and a functional material are added, and low-speed shear mixing is performed to form a composite melt, which is rapidly solidified after high-pressure spraying to obtain a sulfur-based filter material; the amount of the molten dispersion used is 20-50wt% of the sulfur, and the amount of the functional material used is 0.1-8wt% of the sulfur.

6. The synthesis process of a denitrification filter medium according to claim 5, characterized in that: The nucleating agent is molybdenum disulfide.

7. The synthesis process of a denitrification filter material according to claim 5, characterized in that: The rotation speed of the low-speed shearing is 600-1000 rpm, and the mixing time of the low-speed shearing is 10-60 min.

8. The synthesis process of a denitrification filter medium according to claim 5, characterized in that: The temperature of the composite melt during the high-pressure spraying is 110-140°C.

9. The synthesis process of a denitrification filter medium according to claim 5, characterized in that: In the preparation of the molten dispersion, the dispersion material is melted and then added to the oxide composite for mixing, and then dried and crushed to obtain the molten dispersion.

10. Use of a denitrification filter material according to any one of claims 1 to 4 in sewage treatment and / or wastewater purification.

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