A nitrifying bacteria bionest containing a nitrifying bacteria growth promoter, and its preparation method and application

Abstract

The invention relates to the technical field of water treatment, and discloses a nitrifying bacteria bio-nest containing a nitrifying bacteria growth promoter, a preparation method and an application thereof. The raw materials of the nitrifying bacteria bio-nest include the following components: a nitrifying bacteria growth promoter, an inorganic aggregate, a skin-core structure basalt fiber, and a redispersible latex powder; the skin-core structure basalt fiber includes basalt fiber, a bioaffinity modified layer and a calcium carbonate deposition layer from the inside to the outside. The preparation method of the nitrifying bacteria bio-nest includes the following steps: after mixing the nitrifying bacteria growth promoter, the inorganic aggregate, the skin-core structure basalt fiber, the redispersible latex powder and water, forming the mixture, and then soaking the mixture in an acid solution to react the calcium carbonate to obtain a nitrifying bacteria bio-nest. In the nitrifying bacteria bio-nest of the invention, the growth promoter slowly released from the inside can fully contact with the nitrifying bacteria attached and growing therein, so that when used for wastewater treatment, a better nitrification treatment effect can be achieved.

Description

Technical Field

[0001] The invention relates to the technical field of water treatment, and in particular to a nitrifying bacteria bio-nest containing a nitrifying bacteria growth promoter, and a preparation method and application thereof. Background Art

[0002] In industrial, agricultural and animal husbandry production, the discharge of nitrogen-containing wastewater leads to an increase in nitrogen content in surface water and groundwater, which can easily lead to eutrophication of water bodies and endanger human health and biodiversity. Biological denitrification is one of the common methods for harmless treatment of nitrogen-containing wastewater. Nitrifying bacteria include nitrite bacteria and nitrifying bacteria, which can convert reduced nitrogen (such as ammonia nitrogen, organic nitrogen) into hydroxylamine, nitrate nitrogen or nitrite nitrogen, and are an important step in biological denitrification of wastewater.

[0003] Nitrifying bacteria bio-nest refers to a solid medium or carrier that can be put into nitrogen-containing wastewater to provide a place for nitrifying bacteria to grow and reproduce, and to fix nitrifying bacteria. The use of nitrifying bacteria bio-nest can promote the growth and reproduction of nitrifying bacteria and reduce their loss, so that nitrifying bacteria can maintain a high biomass and biological activity in nitrogen-containing wastewater to improve the denitrification effect. At the same time, it can also improve the impact tolerance of the biological denitrification system, so that the system can quickly recover from the chaotic state of denitrification caused by shock loads and sudden factors, and maintain the long-term stability of nitrification.

[0004] Nitrifying bacteria growth promoter can provide nutrients for the growth and reproduction of nitrifying bacteria and nitrification, so that the bacterial flora can be quickly activated and promote biological denitrification. By loading the growth promoter in the biological nest and slowly releasing it during the wastewater treatment process, the growth promoter in the wastewater can be maintained at a relatively stable level during the biological denitrification period, thereby solving the problem of difficult control of the dosage of the growth promoter, avoiding excessive initial release causing organic matter and inorganic ion residues in the wastewater, and insufficient release in the later stage making it difficult to maintain a good denitrification effect.

[0005] The ideal bacterial bio-nest should have good adsorption properties for the bacteria, so that the microorganisms can be enriched therein, and have rich porosity and connected channels, so that the bacterial growth promoter can circulate and transmit therein, and promote bacterial growth and reproduction. Patent CN106517504B discloses a slow-release carbon source filler and its preparation method and application, the slow-release carbon source filler is made of agar, poly-β-hydroxybutyric acid, wetting dispersant, filler, enzymatic activity regulator, processing improver, polymer adhesive and foaming agent, wherein poly-β-hydroxybutyric acid is used as the carbon source, and agar is used as the skeleton carrier of the carbon source, which can achieve the stable release of the carbon source, overcome the problems of decreased microbial metabolic function and decreased pollutant removal effect caused by insufficient carbon source, and avoid excessive release of carbon source to cause organic matter residue in the effluent. The patent uses a foaming agent to increase the porosity inside the slow-release carbon source filler, but it is difficult to significantly promote the circulation and transmission of the carbon source inside the filler, and contact with bacteria to promote their growth and reproduction, which will cause the slow-release carbon source filler to have a poor treatment effect on wastewater. Summary of the invention

[0006] In order to solve the technical problem that the bacterial growth promoter released from the existing bacterial bio-nest cannot effectively contact with the bacteria, the present invention provides a nitrifying bacteria bio-nest containing a nitrifying bacteria growth promoter, a preparation method and application thereof. In the nitrifying bacteria bio-nest, the growth promoter slowly released from the bio-nest can fully contact with the nitrifying bacteria attached and growing therein, providing nutrition for the growth and reproduction of the nitrifying bacteria and the nitrification, so that when used for wastewater treatment, a better nitrification treatment effect can be achieved.

[0007] The specific technical scheme of the present invention is:

[0008] In the first aspect, the present invention provides a nitrifying bacteria bio-nest containing a nitrifying bacteria growth promoter, wherein the raw materials include the following components: a nitrifying bacteria growth promoter, an inorganic aggregate, a skin-core structured basalt fiber, and a redispersible latex powder; the skin-core structured basalt fiber includes, from the inside to the outside, basalt fibers, a bioaffinity modified layer, and a calcium carbonate deposition layer.

[0009] In the nitrifying bacteria bio-nest of the present invention, inorganic aggregates and redispersible latex powder constitute the matrix of the bio-nest, the nitrifying bacteria growth promoter is dispersed in the matrix, and the redispersible latex powder can form a film between the inorganic aggregates, play a role in fixing the inorganic aggregates, and slow down the release of the growth promoter. Compared with agar in the prior art (which needs to be dissolved at a temperature close to 100°C), the film-forming temperature of the redispersible latex powder is lower, and it will not damage the components with poor thermal stability in the growth promoter.

[0010] The skin-core structure basalt fiber adopts a three-layer structure consisting of basalt fiber, bio-affinity modified layer and calcium carbonate deposition layer, which is dispersed in a matrix consisting of inorganic aggregate and redispersible latex powder. The outermost calcium carbonate deposition layer reacts and dissolves under the action of acid solution and releases carbon dioxide, which can form channels in the biological nest. The use of these skin-core structure basalt fibers is conducive to the contact between the growth promoter slowly released in the biological nest and the nitrifying bacteria attached and growing therein, thereby improving the nitrification treatment effect of the nitrifying bacteria biological nest on wastewater. The specific mechanism is as follows:

[0011] ① After calcium carbonate completes pore formation, a gap is formed between the fiber and the matrix, which can provide space for the enrichment of nitrifying bacteria. In addition, the bioaffinity modified layer has good bioaffinity, which is conducive to the attachment of nitrifying bacteria. Therefore, nitrifying bacteria can attach and grow on the bioaffinity modified layer on the surface of basalt fiber to form a nitrifying bacteria film.

[0012] ② In addition to providing space for the enrichment of nitrifying bacteria, the gap formed between the fiber and the matrix can also provide space for the circulation of growth promoters, so that the slowly released growth promoters can flow along the fibers and provide nutrients for the nitrifying bacteria film on the fiber surface; and, in the process of calcium carbonate pore formation, the gas generated forms pores in the bio-nest matrix, and these pores are connected to the fiber surface, which can enable the promoters slowly released from the bio-nest matrix to flow along these pores to the fiber surface, contact with the nitrifying bacteria membrane, and promote the growth and nitrification of nitrifying bacteria.

[0013] 3○ In addition, during the pore-forming process of calcium carbonate, as carbon dioxide is released, pores can be formed in the biological nest, connecting the fiber surface with the outside world, allowing nitrifying bacteria to enter along the pores and then attach to the surface of the bioaffinity modified layer in the fiber to form a nitrifying bacteria membrane, and allowing wastewater to enter from the outside and come into contact with the nitrifying bacteria membrane attached to the fiber surface.

[0014] Through the above ① to ③, the addition of skin-core structure basalt fiber is beneficial for the growth promoter slowly released in the biological nest to provide nutrients for the nitrifying bacteria attached to the fiber surface, thereby promoting the growth of nitrifying bacteria and the nitrification of wastewater.

[0015] Preferably, the raw materials of the bioaffinity modification layer include the following components: nano-silicon dioxide powder, nano-calcium carbonate powder, aminosilane coupling agent, cationic surfactant, and epoxy resin.

[0016] The surface of basalt fiber is smooth, hydrophobic, and negatively charged, which is not conducive to bacterial attachment. When used to immobilize bacteria, its surface needs to be modified by bioaffinity. Among the raw materials of the above-mentioned bioaffinity modified layer, epoxy resin can improve the hydrophilicity of the basalt fiber surface; nano-silicon dioxide powder can form protrusions on the surface of the bioaffinity modified layer to improve the surface roughness; nano-calcium carbonate powder reacts and dissolves and releases carbon dioxide during the pore formation process of the calcium carbonate deposition layer, forming pores in the bioaffinity modified layer, further improving its surface roughness; cationic surfactants can increase the Zeta potential of the surface of the bioaffinity modified layer and reduce the electrostatic repulsion between the fiber surface and bacteria; aminosilane coupling agents can make nano-silicon dioxide powder and nano-calcium carbonate powder evenly dispersed in the bioaffinity modified layer, and reduce the shedding of nano-silicon dioxide powder. In summary, the bioaffinity modified layer of the present invention can improve the hydrophilicity, roughness and bioaffinity of the basalt fiber surface, and promote the attachment and film formation of nitrifying bacteria on its surface.

[0017] Preferably, the method for preparing the skin-core structure basalt fiber comprises the following steps:

[0018] (1) dispersing nano-silicon dioxide powder and nano-calcium carbonate powder in a solvent, adding an aminosilane coupling agent thereto, carrying out a grafting reaction, and obtaining a modified particle dispersion;

[0019] In step (1), the amino group can be grafted onto the surface of the nano-silica powder and the nano-calcium carbonate powder by utilizing the silaneoxy group in the aminosilane coupling agent.

[0020] (2) adding a cationic surfactant and an epoxy resin to the modified particle dispersion, mixing them evenly, and performing a ring-opening reaction to obtain a fiber modified liquid;

[0021] In step (2), the amino groups on the surface of the nano-silicon dioxide powder and the nano-calcium carbonate powder react with the epoxy groups in the epoxy resin to connect the nano-silicon dioxide powder and the nano-calcium carbonate powder to the epoxy resin, which is beneficial for the powder to be evenly dispersed in the bioaffinity modified layer and reduces the shedding of the nano-silicon dioxide powder during the use of the bionest.

[0022] (3) immersing the basalt fiber in a fiber modification liquid, taking it out after immersion, and drying it to obtain a modified basalt fiber; in step (3), the fiber modification liquid forms a bioaffinity modification layer on the surface of the basalt fiber.

[0023] (4) immediately immersing the modified basalt fiber after drying in step (3) in a calcium bicarbonate solution without cooling, and taking it out after immersion to obtain a skin-core structure basalt fiber;

[0024] In step (4), the modified basalt fiber has a relatively high temperature. After being immersed in the calcium bicarbonate solution, the calcium bicarbonate can be decomposed into calcium carbonate on the fiber surface, thereby forming a calcium carbonate deposition layer.

[0025] Furthermore, in steps (1) to (2), the mass ratio of the nano-silicon dioxide powder, the nano-calcium carbonate powder, the aminosilane coupling agent, the cationic surfactant, and the epoxy resin is 1:0.5-1.5:5-7:2-5:50-80.

[0026] Furthermore, in step (1), the grafting reaction temperature is 70-80° C. and the time is 2-4 hours.

[0027] Furthermore, in step (1), the ratio of the total mass of the nano-silicon dioxide powder and the nano-calcium carbonate powder to the volume of the solvent is 1 g: 90-110 mL.

[0028] Furthermore, in step (2), the temperature of the ring-opening reaction is 50-60° C., and the time is 3-4 h.

[0029] Furthermore, in step (3), the infiltration time is 1 to 2 hours.

[0030] Furthermore, in step (3), the drying temperature is 130-150°C.

[0031] Furthermore, in step (4), the concentration of the calcium bicarbonate solution is 12 to 16 wt %, and the soaking time is 20 to 30 min.

[0032] Preferably, the nitrifying bacteria growth promoter comprises the following components in parts by weight: 20-60 parts of magnesium salt, 40-100 parts of ferrous salt, 5-20 parts of manganese salt, 1-20 parts of copper salt, 1-10 parts of zinc salt, 1-20 parts of vitamins, and 1-20 parts of rhamnolipid.

[0033] The above formula can provide more comprehensive nutrition for nitrifying bacteria, enable them to grow and reproduce rapidly in a short period of time, and promote their nitrification.

[0034] Furthermore, the vitamins include one or more of vitamin B1, vitamin B2 and vitamin C.

[0035] Preferably, the inorganic aggregate includes one or more of quartz sand, attapulgite, diatomaceous earth, bentonite and talc.

[0036] Preferably, the raw materials of the nitrifying bacteria bio-nest include the following components by weight: 10-20 parts of nitrifying bacteria growth promoter, 30-50 parts of inorganic aggregate, 5-13 parts of skin-core structure basalt fiber, and 3.5-5.5 parts of redispersible latex powder.

[0037] In a second aspect, the present invention provides a method for preparing the nitrifying bacteria bio-nest, comprising the following steps: mixing a nitrifying bacteria growth promoter, inorganic aggregate, skin-core structure basalt fiber, redispersible latex powder and water, forming the mixture, and then soaking the mixture in an acid solution to react calcium carbonate to obtain a nitrifying bacteria bio-nest.

[0038] In a third aspect, the present invention provides the use of the nitrifying bacteria bio-nest in wastewater treatment.

[0039] Compared with the prior art, the present invention has the following advantages:

[0040] (1) In the nitrifying bacteria bio-nest of the present invention, by using a special skin-core structure basalt fiber, the growth promoter slowly released from the bio-nest can fully contact with the nitrifying bacteria attached and growing therein, thereby improving the nitrification treatment effect of the nitrifying bacteria bio-nest on wastewater;

[0041] (2) In the skin-core structure basalt fiber used in the present invention, by adding nano calcium carbonate powder to the raw materials of the bioaffinity modification layer, the roughness of the bioaffinity modification layer can be increased, thereby promoting the attachment and film formation of nitrifying bacteria on the fiber surface. DETAILED DESCRIPTION

[0042] The present invention will be further described below in conjunction with the embodiments.

[0043] Overall embodiment

[0044] A nitrifying bacteria bio-nest containing a nitrifying bacteria growth promoter, the raw materials of which include the following components: the nitrifying bacteria growth promoter, inorganic aggregate, skin-core structure basalt fiber, and redispersible latex powder; the skin-core structure basalt fiber includes basalt fiber, a bioaffinity modified layer, and a calcium carbonate deposition layer from the inside to the outside.

[0045] In some specific embodiments, the raw materials of the nitrifying bacteria bio-nest include the following components by weight: 10 to 20 parts of nitrifying bacteria growth promoter, 30 to 50 parts of inorganic aggregate, 5 to 13 parts of skin-core structure basalt fiber, and 3.5 to 5.5 parts of redispersible latex powder.

[0046] In some specific embodiments, the method for preparing the skin-core structure basalt fiber comprises the following steps:

[0047] (1) dispersing nano-silicon dioxide powder and nano-calcium carbonate powder in a solvent, adding an aminosilane coupling agent thereto, and carrying out a grafting reaction (temperature of 70 to 80° C., time of 2 to 4 hours) to obtain a modified particle dispersion; the ratio of the total mass of the nano-silicon dioxide powder and the nano-calcium carbonate powder to the volume of the solvent is 1 g: 90 to 110 mL;

[0048] (2) adding a cationic surfactant and an epoxy resin to the modified particle dispersion, mixing, and performing a ring-opening reaction (temperature of 50 to 60° C., time of 3 to 4 hours) to obtain a fiber modified liquid; the mass ratio of the nano-silicon dioxide powder, the nano-calcium carbonate powder, the aminosilane coupling agent, the cationic surfactant, and the epoxy resin is 1:0.5 to 1.5:5 to 7:2 to 5:50 to 80;

[0049] (3) immersing the basalt fiber in the fiber modification liquid, taking it out after soaking for 1 to 2 hours, and drying it (temperature is 130 to 150° C., time is 0.5 to 1 hour) to obtain modified basalt fiber;

[0050] (4) The modified basalt fiber after drying in step (3) is immediately immersed in a 12-16 wt % calcium bicarbonate solution without cooling, and taken out after soaking for 20-30 minutes to obtain a skin-core structure basalt fiber.

[0051] In some specific embodiments, the nitrifying bacteria growth promoter includes the following components in parts by weight: 20-60 parts of magnesium salt, 40-100 parts of ferrous salt, 5-20 parts of manganese salt, 1-20 parts of copper salt, 1-10 parts of zinc salt, 1-20 parts of vitamins, and 1-20 parts of rhamnolipid.

[0052] Optionally, the vitamins include one or more of vitamin B1, vitamin B2 and vitamin C.

[0053] In some specific embodiments, the inorganic aggregate includes one or more of quartz sand, attapulgite, diatomaceous earth, bentonite and talc.

[0054] A method for preparing the nitrifying bacteria bio-nest comprises the following steps: mixing a nitrifying bacteria growth promoter, inorganic aggregate, skin-core structure basalt fiber, redispersible latex powder and water, forming the mixture, and then soaking the mixture in an acid solution to react calcium carbonate to obtain a nitrifying bacteria bio-nest.

[0055] The application of the nitrifying bacteria bio-nest in wastewater treatment.

[0056] Example 1

[0057] A nitrifying bacteria bio-nest containing a nitrifying bacteria growth promoter is prepared by the following steps:

[0058] (1) Preparation of nitrifying bacteria growth promoter:

[0059] (1.1) Weigh by weight: 30 parts of magnesium sulfate, 60 parts of ferrous sulfate, 10 parts of manganese sulfate, 10 parts of copper sulfate, 5 parts of zinc sulfate, 15 parts of vitamins, and 15 parts of rhamnolipid;

[0060] (1.2) All raw materials are separated into particles and lumps using a FAST-600 single-layer rotary vibrating screen with a mesh size of 30. The particles can be used directly, while the lumps need to be broken into particles by a crusher before use;

[0061] (1.3) All the raw materials processed in step (1.2) are mixed evenly using a mixer to obtain a nitrifying bacteria growth promoter.

[0062] (2) Preparation of skin-core structure basalt fiber:

[0063] (2.1) Weigh by weight: 1 part of nano-silicon dioxide powder, 1 part of nano-calcium carbonate powder, 5-7 parts of silane coupling agent KH-550, 2-5 parts of hexadecyltrimethylammonium chloride, and 50-80 parts of epoxy resin;

[0064] (2.2) Take nano-silicon dioxide powder and nano-calcium carbonate powder, add them to ethanol aqueous solution (the volume ratio of ethanol to water is 1:1.5) according to the solid-liquid ratio of 1g:100mL, after ultrasonic dispersion for 10 minutes, add silane coupling agent KH-550, heat reflux reaction at 75°C for 3 hours, and obtain modified particle dispersion;

[0065] (2.3) adding hexadecyltrimethylammonium chloride and epoxy resin to the modified particle dispersion, stirring at high speed to uniformly obtain the modified particle dispersion, and stirring at 55° C. for 3.5 h to obtain a fiber modified solution;

[0066] (2.4) Basalt fibers with a diameter of 13 μm were immersed in a fiber modification solution at a mass volume ratio of 1 g:10 mL, taken out after immersion for 1.5 h, dried at 140°C for 0.5 h, and immediately immersed in a 15 wt% calcium bicarbonate solution at a mass volume ratio of 1 g:20 mL. After immersion for 30 min, they were taken out and dried at 120°C to constant weight to obtain a skin-core structured basalt fiber.

[0067] (3) Preparation of nitrifying bacteria bionest:

[0068] (3.1) Weigh the following by weight: 15 parts of nitrifying bacteria growth promoter, 20 parts of quartz sand, 18 parts of attapulgite, 10 parts of skin-core structure basalt fiber, 4.5 parts of ethylene-vinyl acetate copolymer latex powder, and 15 parts of water;

[0069] (3.2) Mix all the raw materials evenly with a mixer, inject the obtained slurry into a mold, and demould after drying to obtain a bionest blank;

[0070] (3.3) Immerse the bio-nest blank in 10 wt % hydrochloric acid at a ratio of 1 g:20 mL, take it out after soaking for 1.5 h, rinse it with water until it is neutral, drain it, and obtain the nitrifying bacteria bio-nest.

[0071] Example 2

[0072] A nitrifying bacteria bio-nest containing a nitrifying bacteria growth promoter is prepared by the following steps:

[0073] (1) Preparation of nitrifying bacteria growth promoter:

[0074] (1.1) Weigh by weight: 20 parts of magnesium sulfate, 100 parts of ferrous sulfate, 5 parts of manganese sulfate, 1 part of copper sulfate, 10 parts of zinc sulfate, 1 part of vitamins, and 20 parts of rhamnolipid;

[0075] (1.2) All raw materials are separated into particles and lumps using a FAST-600 single-layer rotary vibrating screen with a mesh size of 30. The particles can be used directly, while the lumps need to be broken into particles by a crusher before use;

[0076] (1.3) All the raw materials processed in step (1.2) are mixed evenly using a mixer to obtain a nitrifying bacteria growth promoter.

[0077] (2) Preparation of skin-core structure basalt fiber:

[0078] (2.1) Weigh by weight: 1 part of nano-silicon dioxide powder, 1.5 parts of nano-calcium carbonate powder, 5-7 parts of silane coupling agent KH-550, 2-5 parts of hexadecyltrimethylammonium chloride, and 50-80 parts of epoxy resin;

[0079] (2.2) Take nano-silicon dioxide powder and nano-calcium carbonate powder, add them to ethanol aqueous solution (the volume ratio of ethanol to water is 1:1.5) according to the solid-liquid ratio of 1g:100mL, after ultrasonic dispersion for 10 minutes, add silane coupling agent KH-550, heat reflux reaction at 70°C for 4 hours, and obtain modified particle dispersion;

[0080] (2.3) adding hexadecyltrimethylammonium chloride and epoxy resin to the modified particle dispersion, stirring at high speed to uniformly obtain the modified particle dispersion, and stirring at 60° C. for 3 h to obtain a fiber modified solution;

[0081] (2.4) Basalt fibers with a diameter of 13 μm were immersed in a fiber modification solution at a mass volume ratio of 1 g:10 mL, taken out after immersion for 1 hour, dried at 150°C for 0.5 hour, and immediately immersed in a 12 wt% calcium bicarbonate solution at a mass volume ratio of 1 g:20 mL. After immersion for 30 minutes, they were taken out and dried at 120°C to constant weight to obtain a skin-core structured basalt fiber.

[0082] (3) Preparation of nitrifying bacteria bio-nest:

[0083] (3.1) Weigh the following by weight: 10 parts of nitrifying bacteria growth promoter, 30 parts of quartz sand, 20 parts of attapulgite, 13 parts of skin-core structure basalt fiber, 5.5 parts of ethylene-vinyl acetate copolymer latex powder, and 20 parts of water;

[0084] (3.2) Mix all the raw materials evenly with a mixer, inject the obtained slurry into a mold, and demould after drying to obtain a bionest blank;

[0085] (3.3) Immerse the bio-nest blank in 10 wt % hydrochloric acid at a ratio of 1 g:20 mL, take it out after soaking for 2 hours, rinse it with water until it is neutral, drain it, and obtain the nitrifying bacteria bio-nest.

[0086] Example 3

[0087] A nitrifying bacteria bio-nest containing a nitrifying bacteria growth promoter is prepared by the following steps:

[0088] (1) Preparation of nitrifying bacteria growth promoter:

[0089] (1.1) Weigh by weight: 60 parts of magnesium sulfate, 40 parts of ferrous sulfate, 20 parts of manganese sulfate, 20 parts of copper sulfate, 1 part of zinc sulfate, 20 parts of vitamins, and 5 parts of rhamnolipid;

[0090] (1.2) All raw materials are separated into particles and lumps using a FAST-600 single-layer rotary vibrating screen with a mesh size of 30. The particles can be used directly, while the lumps need to be broken into particles by a crusher before use;

[0091] (1.3) All the raw materials processed in step (1.2) are mixed evenly using a mixer to obtain a nitrifying bacteria growth promoter.

[0092] (2) Preparation of skin-core structure basalt fiber:

[0093] (2.1) Weigh by weight: 1 part of nano-silicon dioxide powder, 0.5 parts of nano-calcium carbonate powder, 5-7 parts of silane coupling agent KH-550, 2-5 parts of hexadecyltrimethylammonium chloride, and 50-80 parts of epoxy resin;

[0094] (2.2) Take nano-silicon dioxide powder and nano-calcium carbonate powder, add them to ethanol aqueous solution (the volume ratio of ethanol to water is 1:1.5) according to the solid-liquid ratio of 1g:100mL, after ultrasonic dispersion for 10 minutes, add silane coupling agent KH-550, heat reflux reaction at 80°C for 2 hours, and obtain modified particle dispersion;

[0095] (2.3) adding hexadecyltrimethylammonium chloride and epoxy resin to the modified particle dispersion, stirring at high speed to uniformly obtain the modified particle dispersion, and stirring at 50° C. for 4 h to obtain a fiber modified solution;

[0096] (2.4) Basalt fibers with a diameter of 13 μm were immersed in a fiber modification solution at a mass volume ratio of 1 g:10 mL, taken out after immersion for 2 h, dried at 130°C for 1 h, and immediately immersed in a 16 wt% calcium bicarbonate solution at a mass volume ratio of 1 g:20 mL. After immersion for 20 min, they were taken out and dried at 120°C to constant weight to obtain skin-core structured basalt fibers.

[0097] (3) Preparation of nitrifying bacteria bio-nest:

[0098] (3.1) Weigh the following by weight: 20 parts of nitrifying bacteria growth promoter, 15 parts of quartz sand, 15 parts of attapulgite, 5 parts of skin-core basalt fiber, 3.5 parts of ethylene-vinyl acetate copolymer latex powder, and 10 parts of water;

[0099] (3.2) Mix all the raw materials evenly with a mixer, inject the obtained slurry into a mold, and demould after drying to obtain a bionest blank;

[0100] (3.3) Immerse the bio-nest blank in 10 wt % hydrochloric acid at a ratio of 1 g:20 mL, take it out after soaking for 1 hour, rinse it with water until it is neutral, drain it, and obtain the nitrifying bacteria bio-nest.

[0101] Example 4

[0102] A nitrifying bacteria bio-nest containing a nitrifying bacteria growth promoter is prepared by the following steps:

[0103] (1) Preparation of nitrifying bacteria growth promoter:

[0104] (1.1) Weigh by weight: 30 parts of magnesium sulfate, 60 parts of ferrous sulfate, 10 parts of manganese sulfate, 10 parts of copper sulfate, 5 parts of zinc sulfate, 15 parts of vitamins, and 15 parts of rhamnolipid;

[0105] (1.2) All raw materials are separated into particles and lumps using a FAST-600 single-layer rotary vibrating screen with a mesh size of 30. The particles can be used directly, while the lumps need to be broken into particles by a crusher before use;

[0106] (1.3) All the raw materials processed in step (1.2) are mixed evenly using a mixer to obtain a nitrifying bacteria growth promoter.

[0107] (2) Preparation of skin-core structure basalt fiber:

[0108] (2.1) Weigh by weight: 1 part of nano-silica powder, 5-7 parts of silane coupling agent KH-550, 2-5 parts of hexadecyltrimethylammonium chloride, and 50-80 parts of epoxy resin;

[0109] (2.2) Take nano-silica powder and add it to an ethanol aqueous solution (the volume ratio of ethanol to water is 1:1.5) at a solid-liquid ratio of 0.5 g:100 mL. After ultrasonic dispersion for 10 min, add silane coupling agent KH-550 and heat under reflux at 75 °C for 3 h to obtain a modified particle dispersion.

[0110] (2.3) adding hexadecyltrimethylammonium chloride and epoxy resin to the modified particle dispersion, stirring at high speed to uniformly obtain the modified particle dispersion, and stirring at 55° C. for 3.5 h to obtain a fiber modified solution;

[0111] (2.4) Basalt fibers with a diameter of 13 μm were immersed in a fiber modification solution at a mass volume ratio of 1 g:10 mL, taken out after immersion for 1.5 h, dried at 140°C for 0.5 h, and immediately immersed in a 15 wt% calcium bicarbonate solution at a mass volume ratio of 1 g:20 mL. After immersion for 30 min, they were taken out and dried at 120°C to constant weight to obtain a skin-core structured basalt fiber.

[0112] (3) Preparation of nitrifying bacteria bio-nest:

[0113] (3.1) Weigh the following by weight: 15 parts of nitrifying bacteria growth promoter, 20 parts of quartz sand, 18 parts of attapulgite, 10 parts of skin-core structure basalt fiber, 4.5 parts of ethylene-vinyl acetate copolymer latex powder, and 15 parts of water;

[0114] (3.2) Mix all the raw materials evenly with a mixer, inject the obtained slurry into a mold, and demould after drying to obtain a bionest blank;

[0115] (3.3) Immerse the bio-nest blank in 10 wt % hydrochloric acid at a ratio of 1 g:20 mL, take it out after soaking for 1.5 h, rinse it with water until it is neutral, drain it, and obtain the nitrifying bacteria bio-nest.

[0116] Comparative Example 1

[0117] A nitrifying bacteria bio-nest containing a nitrifying bacteria growth promoter is prepared by the following steps:

[0118] (1) Preparation of nitrifying bacteria growth promoter:

[0119] (1.1) Weigh by weight: 30 parts of magnesium sulfate, 60 parts of ferrous sulfate, 10 parts of manganese sulfate, 10 parts of copper sulfate, 5 parts of zinc sulfate, 15 parts of vitamins, and 15 parts of rhamnolipid;

[0120] (1.2) All raw materials are separated into particles and lumps using a FAST-600 single-layer rotary vibrating screen with a mesh size of 30. The particles can be used directly, while the lumps need to be broken into particles by a crusher before use;

[0121] (1.3) All the raw materials processed in step (1.2) are mixed evenly using a mixer to obtain a nitrifying bacteria growth promoter.

[0122] (2) Preparation of nitrifying bacteria bio-nest:

[0123] (2.1) Weigh the following by weight: 15 parts of nitrifying bacteria growth promoter, 20 parts of quartz sand, 18 parts of attapulgite, 3.5 parts of calcium carbonate, 4.5 parts of ethylene-vinyl acetate copolymer latex powder, and 15 parts of water;

[0124] (2.2) Mix all the raw materials evenly with a mixer, inject the obtained slurry into a mold, and demould after drying to obtain a bionest blank;

[0125] (2.3) Immerse the bio-nest blank in 10 wt % hydrochloric acid at a ratio of 1 g:20 mL, take it out after soaking for 1.5 h, rinse it with water until it is neutral, drain it, and obtain the nitrifying bacteria bio-nest.

[0126] Comparative Example 2

[0127] A nitrifying bacteria bio-nest containing a nitrifying bacteria growth promoter is prepared by the following steps:

[0128] (1) Preparation of nitrifying bacteria growth promoter:

[0129] (1.1) Weigh by weight: 30 parts of magnesium sulfate, 60 parts of ferrous sulfate, 10 parts of manganese sulfate, 10 parts of copper sulfate, 5 parts of zinc sulfate, 15 parts of vitamins, and 15 parts of rhamnolipid;

[0130] (1.2) All raw materials are separated into particles and lumps using a FAST-600 single-layer rotary vibrating screen with a mesh size of 30. The particles can be used directly, while the lumps need to be broken into particles by a crusher before use;

[0131] (1.3) All the raw materials processed in step (1.2) are mixed evenly using a mixer to obtain a nitrifying bacteria growth promoter.

[0132] (2) Preparation of skin-core structure basalt fiber:

[0133] (2.1) Weigh by weight: 1 part of nano-silicon dioxide powder, 1 part of nano-calcium carbonate powder, 5-7 parts of silane coupling agent KH-550, 2-5 parts of hexadecyltrimethylammonium chloride, and 50-80 parts of epoxy resin;

[0134] (2.2) Take nano-silicon dioxide powder and nano-calcium carbonate powder, add them to ethanol aqueous solution (the volume ratio of ethanol to water is 1:1.5) according to the solid-liquid ratio of 1g:100mL, after ultrasonic dispersion for 10 minutes, add silane coupling agent KH-550, heat reflux reaction at 75°C for 3 hours, and obtain modified particle dispersion;

[0135] (2.3) adding hexadecyltrimethylammonium chloride and epoxy resin to the modified particle dispersion, stirring at high speed to uniformly obtain the modified particle dispersion, and stirring at 55° C. for 3.5 h to obtain a fiber modified solution;

[0136] (2.4) A basalt fiber with a diameter of 13 μm was immersed in a fiber modification solution at a mass volume ratio of 1 g:10 mL, taken out after immersion for 1.5 h, and dried at 140 °C to constant weight to obtain a skin-core structured basalt fiber.

[0137] (3) Preparation of nitrifying bacteria bionest:

[0138] (3.1) Weigh the following by weight: 15 parts of nitrifying bacteria growth promoter, 20 parts of quartz sand, 18 parts of attapulgite, 10 parts of skin-core basalt fiber, 3.5 parts of calcium carbonate, 4.5 parts of ethylene-vinyl acetate copolymer latex powder, and 15 parts of water;

[0139] (3.2) Mix all the raw materials evenly with a mixer, inject the obtained slurry into a mold, and demould after drying to obtain a bionest blank;

[0140] (3.3) Immerse the bio-nest blank in 10 wt % hydrochloric acid at a ratio of 1 g:20 mL, take it out after soaking for 1.5 h, rinse it with water until it is neutral, drain it, and obtain the nitrifying bacteria bio-nest.

[0141] Comparative Example 3

[0142] A nitrifying bacteria bio-nest containing a nitrifying bacteria growth promoter is prepared by the following steps:

[0143] (1) Preparation of nitrifying bacteria growth promoter:

[0144] (1.1) Weigh by weight: 30 parts of magnesium sulfate, 60 parts of ferrous sulfate, 10 parts of manganese sulfate, 10 parts of copper sulfate, 5 parts of zinc sulfate, 15 parts of vitamins, and 15 parts of rhamnolipid;

[0145] (1.2) All raw materials are separated into particles and lumps using a FAST-600 single-layer rotary vibrating screen with a mesh size of 30. The particles can be used directly, while the lumps need to be broken into particles by a crusher before use;

[0146] (1.3) All the raw materials processed in step (1.2) are mixed evenly using a mixer to obtain a nitrifying bacteria growth promoter.

[0147] (2) Preparation of skin-core structure basalt fiber:

[0148] After heat treatment at 140°C for 0.5h, basalt fiber with a diameter of 13 μm was immediately immersed in a 15wt% calcium bicarbonate solution at a mass volume ratio of 1g:20mL, taken out after immersion for 30min, and dried at 120°C to constant weight to obtain a skin-core structured basalt fiber.

[0149] (3) Preparation of nitrifying bacteria bionest:

[0150] (3.1) Weigh the following by weight: 15 parts of nitrifying bacteria growth promoter, 20 parts of quartz sand, 18 parts of attapulgite, 10 parts of skin-core structure basalt fiber, 4.5 parts of ethylene-vinyl acetate copolymer latex powder, and 15 parts of water;

[0151] (3.2) Mix all the raw materials evenly with a mixer, inject the obtained slurry into a rectangular mold of 6 cm × 3 cm × 3 cm, and demould after drying to obtain a bionest blank;

[0152] (3.3) Immerse the bio-nest blank in 10 wt % hydrochloric acid at a ratio of 1 g:20 mL, take it out after soaking for 1.5 h, rinse it with water until it is neutral, drain it, and obtain the nitrifying bacteria bio-nest.

[0153] Application Examples

[0154] The nitrifying bacteria bio-nests prepared in Examples 1 to 4 and Comparative Examples 1 to 3 were used to carry out wastewater nitrification treatment. The specific process is as follows: 5 L of production wastewater (COD of 1100 mg / L, ammonia nitrogen concentration of 200 mg / L) from a pharmaceutical factory in Taizhou City, Zhejiang Province was taken, 50 g of the bio-nest and 1 g of the nitrifying bacteria agent were added, the dissolved oxygen content in the wastewater was controlled to be 4.5±0.5 mg / L, and the temperature was 30±1°C, and the wastewater was nitrified. From the addition of the bio-nest and the bacteria agent, samples were taken at regular intervals to detect the ammonia nitrogen content, and the results are shown in Table 1.

[0155] Table 1 Changes of ammonia nitrogen concentration in wastewater (in mg / L) over time

[0156] 18h after adding 48h after adding 66h after adding 90h after adding 114h after adding No bio-nest added 199.0 196.8 193.6 189.9 184.5 Example 1 181.2 128.6 88.7 31.6 8.4 Example 2 182.9 134.3 96.0 36.2 9.6 Example 3 190.4 144.5 106.3 47.5 20.7 Example 4 190.8 146.0 110.5 56.2 26.8 Comparative Example 1 195.7 160.3 132.6 91.6 68.0 Comparative Example 2 193.3 154.6 119.2 69.4 45.3 Comparative Example 3 192.9 157.6 127.4 84.3 59.8

[0157] Comparing the effects of the wastewater nitrification treatment of the bionests of the embodiments and the comparative examples in the above table, it can be seen that:

[0158] (1) Compared with the case without adding the bio-nest, the ammonia nitrogen removal efficiency of Examples 1 to 4 and Comparative Examples 1 to 3 is significantly higher, indicating that by adding the bio-nest, nitrifying bacteria can be quickly activated and their nitrification of wastewater can be promoted.

[0159] (2) The ammonia nitrogen removal efficiency of Example 1 is significantly higher than that of Comparative Examples 1 and 2, indicating that compared with the dispersed addition of porogen calcium carbonate, the present invention deposits it on the surface of the skin-core structure basalt fiber, which can improve the effect of the biological nest in promoting the nitrification treatment of wastewater. The reason is that: the calcium carbonate pores on the surface of the skin-core structure basalt fiber can form a gap between the fiber and the matrix, providing space for the attachment of bacteria and the circulation of growth promoters along the fiber, and the gas generated during the pore formation of calcium carbonate forms channels in the matrix, which can connect the fiber surface with the outside world and the inside of the biological nest matrix. In this way, nitrifying bacteria can enter the biological nest and be enriched on the fiber surface, which is conducive to the contact of the slowly released growth promoter with the nitrifying bacteria on the fiber surface, and the wastewater can enter the biological nest and contact with the nitrifying bacteria membrane on the fiber surface, thereby promoting the growth and reproduction of nitrifying bacteria and the nitrification of wastewater.

[0160] (3) Compared with Comparative Example 3, Example 1 has a higher ammonia nitrogen removal efficiency, indicating that by setting a bioaffinity modification layer on the surface of basalt fiber, the effect of the bio-nest in promoting wastewater nitrification treatment can be improved. The reason is that the surface of basalt fiber is smooth, hydrophobic, and negatively charged, which is not conducive to bacterial attachment. However, after the surface is modified by the method of the present invention and a bioaffinity modification layer is formed on its surface, the hydrophilicity, roughness and bioaffinity of the basalt fiber surface can be improved, and the attachment and film formation of nitrifying bacteria on its surface can be promoted, thereby facilitating the bio-nest to play a role in promoting the growth of nitrifying bacteria and nitrification metabolism.

[0161] (4) Compared with Example 4, the ammonia nitrogen removal efficiency of Example 1 is significantly higher, indicating that by adding calcium carbonate to the bioaffinity modified layer, the effect of the bionest in promoting wastewater nitrification treatment can be improved. The reason is that during the pore formation process of the calcium carbonate deposition layer, the nano calcium carbonate powder in the bioaffinity modified layer will also react and dissolve and release carbon dioxide, forming pores in the bioaffinity modified layer, increasing its surface roughness, and further promoting the attachment and film formation of nitrifying bacteria on its surface.

[0162] The raw materials and equipment used in the present invention, unless otherwise specified, are all commonly used raw materials and equipment in the art; the methods used in the present invention, unless otherwise specified, are all conventional methods in the art.

[0163] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent transformation made to the above embodiment based on the technical essence of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A method for preparing a nitrifying bacteria bio-nest containing a nitrifying bacteria growth promoter, characterized in that the steps include: S1: Disperse nano-SiO2 powder and nano-CaCO3 powder in a solvent, add an aminosilane coupling agent, carry out a grafting reaction, obtain a modified particle dispersion, add a cationic surfactant and an epoxy resin, mix well, carry out a ring-opening reaction, and obtain a fiber modification liquid; immerse the basalt fiber in the fiber modification liquid, take it out after immersion, dry it at 130-150°C, immerse it in a Ca(HCO3)2 solution immediately without cooling, take it out after immersion, and obtain a skin-core structure basalt fiber including basalt fiber, a bioaffinity modification layer and a CaCO3 deposition layer from the inside to the outside; S2: The raw materials including nitrifying bacteria growth promoter, inorganic aggregate, skin-core structure basalt fiber and redispersible latex powder are made into nitrifying bacteria bio-nest.

2. The preparation method according to claim 1, characterized in that In step S1, the mass ratio of the nano-SiO2 powder, the nano-CaCO3 powder, the aminosilane coupling agent, the cationic surfactant, and the epoxy resin is 1:0.5~1.5:5~7:2~5:50~80.

3. The preparation method according to claim 1, characterized in that: In step S1, the concentration of the Ca(HCO3)2 solution is 12-16 wt%.

4. The preparation method according to claim 1 or 3, characterized in that: In step S1, the soaking time is 20 to 30 minutes.

5. The preparation method according to claim 1, characterized in that: In step S2, the nitrifying bacteria growth promoter includes the following components in parts by weight: 20-60 parts of magnesium salt, 40-100 parts of ferrous salt, 5-20 parts of manganese salt, 1-20 parts of copper salt, 1-10 parts of zinc salt, 1-20 parts of vitamins, and 1-20 parts of rhamnolipid.

6. The preparation method according to claim 1, characterized in that: In step S2, the raw materials of the nitrifying bacteria bio-nest include the following components by weight: 10-20 parts of nitrifying bacteria growth promoter, 30-50 parts of inorganic aggregate, 5-13 parts of skin-core structure basalt fiber, and 3.5-5.5 parts of redispersible latex powder.

7. The preparation method according to claim 1, characterized in that: The specific process of step S2 includes the following steps: mixing the nitrifying bacteria growth promoter, inorganic aggregate, skin-core structure basalt fiber, redispersible latex powder and water, forming the mixture, and then soaking the mixture in an acid solution to react CaCO3 to obtain a nitrifying bacteria bio-nest.

8. A nitrifying bacteria bio-nest prepared by the preparation method according to any one of claims 1 to 7.

9. Use of the nitrifying bacteria bio-nest as claimed in claim 8 in wastewater treatment.