A microbial treatment method for ammonia nitrogen wastewater

Abstract

The present invention relates to the technical field of water treatment, and discloses a microbial treatment method for ammonia nitrogen wastewater, comprising the following steps: adding activated sludge and microbial carriers into a biological treatment device, passing acclimation water containing ammonia nitrogen, performing acclimation and biofilm formation, and then passing the ammonia nitrogen wastewater to be treated into the biological treatment device for nitrification treatment; wherein the raw materials of the microbial carrier include a slow-release matrix material, a modified activated carbon fiber and a nitrifying bacteria growth promoter, the modified activated carbon fiber is an activated carbon fiber whose surface is sequentially provided with an ammonium bicarbonate layer and a water-insulating layer from the inside to the outside, and the microbial carrier is obtained by mixing and molding various raw materials and then heat-treating to form pores. In the microbial treatment process of ammonia nitrogen wastewater, the present invention can promote the circulation of the nitrifying bacteria growth promoter in the microbial carrier by adopting a special microbial carrier, and contact with the surface of the activated carbon fiber and the nitrifying bacteria membrane, thereby shortening the acclimation and biofilm formation time, and improving the wastewater nitrification treatment efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of water treatment, and in particular to a microbial treatment method for ammonia nitrogen wastewater. Background Art

[0002] Ammonia nitrogen wastewater usually refers to wastewater containing a large amount of NH3 and NH4 + The sources of wastewater include livestock and poultry breeding wastewater, farmland production tail water, industrial wastewater, urban wastewater, garbage leachate, etc. After ammonia nitrogen wastewater is discharged into the water body, it is easy to cause eutrophication of the water body. In severe cases, it will cause large-scale death of aquatic organisms and cause respiratory diseases after entering the human body. At present, the prevention and control of ammonia nitrogen pollution has become one of the focuses of environmental protection.

[0003] Common treatment methods for ammonia nitrogen wastewater include physical methods (such as air stripping, adsorption, membrane separation), chemical methods (such as chemical precipitation, electrochemical oxidation, breakpoint chlorination) and biological methods. Among them, nitrification and denitrification is a typical biological treatment method for ammonia nitrogen wastewater, which first converts ammonia nitrogen into nitrates using nitrifying bacteria under aerobic conditions, and then uses denitrifying bacteria under anoxic conditions to reduce nitrates to harmless nitrogen gas, thereby achieving harmless treatment of ammonia nitrogen in wastewater.

[0004] In the process of wastewater nitrification treatment, by adding nitrifying bacteria growth promoter, it is possible to provide nutrients for the growth and reproduction of nitrifying bacteria and nitrification, so that the initial nitrifying bacteria can be quickly activated, and biological denitrification is promoted. In the prior art, microbial growth promoters are often loaded in carrier fillers, which can not only enable the microbial growth promoter to be released smoothly during the wastewater treatment process, avoid excessive initial additions causing organic matter and inorganic ion residues in the wastewater, and insufficient residual amounts in the later stage making it difficult to maintain a good wastewater treatment effect, but also adsorb microorganisms, provide a place for their growth and reproduction, reduce the loss of microorganisms, improve wastewater treatment efficiency, and improve the system's ability to withstand shocks.

[0005] Patent CN109775860B discloses an immobilized microbial carrier filler and a preparation method thereof, wherein the main ingredients, a slow-release agent (i.e., a nutrient), and a nutrient agent are kneaded and formed, and a foaming agent and a foaming catalyst are added to the kneading and forming system, and then hardened to obtain an immobilized microbial carrier filler. The patent increases the porosity and roughness of the surface of the carrier filler by adding a foaming agent during the preparation process, which can provide a channel for the fixation and growth of microorganisms, but these holes are difficult to significantly promote the circulation of the slowly released nutrients inside the carrier filler and contact with the bacteria attached to the carrier filler, so as to promote the rapid activation of microorganisms in the initial stage of wastewater treatment and improve the biological treatment efficiency of wastewater. Summary of the invention

[0006] In order to solve the technical problem that the existing microbial carriers are difficult to significantly promote the slow-released nutrients to circulate inside them and contact with the bacteria attached therein, the present invention provides a microbial treatment method for ammonia nitrogen wastewater. In the microbial treatment process of ammonia nitrogen wastewater, the present invention adopts a special microbial carrier to promote the nitrifying bacteria growth promoter to circulate in the microbial carrier and contact with the surface of activated carbon fiber and nitrifying bacteria membrane, thereby shortening the acclimatization and biofilm formation time and improving the wastewater nitrification treatment efficiency.

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

[0008] A microbial treatment method for ammonia nitrogen wastewater comprises the following steps:

[0009] Step S1: adding activated sludge and microbial carriers into a biological treatment device, and introducing acclimation water containing ammonia nitrogen to perform acclimation and biofilm formation; the raw materials of the microbial carrier include a slow-release matrix material, modified activated carbon fiber and a nitrifying bacteria growth promoter, the modified activated carbon fiber is an activated carbon fiber with an ammonium bicarbonate layer and a water-insulating layer arranged on the surface from the inside to the outside in sequence, and the microbial carrier is obtained by mixing and molding the raw materials and then subjecting them to heat treatment to form pores;

[0010] Step S2: After the completion of acclimatization and biofilm formation, the ammonia nitrogen wastewater to be treated is passed into a biological treatment device for nitrification treatment.

[0011] Activated carbon fiber is a carbon fiber activated by high temperature, has strong adsorption to microorganisms, and can be used as a biofilm carrier for microbial treatment of wastewater. The present invention provides an ammonium bicarbonate layer on the surface of the activated carbon fiber, and provides a water-proof layer outside the ammonium bicarbonate layer, which is added to the microbial carrier, and water needs to be added during the mixing and molding process, and the water-proof layer can prevent the ammonium bicarbonate layer from being dissolved by water; in the pore-forming process after the mixing and molding, the ammonium bicarbonate on the surface of the activated carbon fiber is decomposed into gas, so that a gap is formed between the activated carbon fiber and the slow-release matrix, and the carbon dioxide and ammonia generated by the decomposition of ammonium bicarbonate can expand the gap between the activated carbon fiber and the slow-release matrix during the process of outward release, and form a channel in the slow-release matrix that connects the surface of the activated carbon fiber and the outside of the slow-release matrix.

[0012] When the above-mentioned microbial carrier is used for ammonia nitrogen wastewater treatment, the channels connected to the surface of the activated carbon fiber and the outside of the slow-release matrix distributed inside the slow-release matrix can make the ammonia nitrogen in the wastewater and the nitrifying bacteria added externally enter the slow-release matrix and reach the surface of the activated carbon fiber. The gap between the activated carbon fiber and the slow-release matrix can provide space for the attachment and growth of nitrifying bacteria, so that the nitrifying bacteria can form a nitrifying bacteria film on the surface of the activated carbon fiber. At the same time, the channels connected to the surface of the activated carbon fiber inside the slow-release matrix are used to facilitate the diffusion of the nitrifying bacteria growth promoter released from the slow-release matrix to the surface of the activated carbon fiber, and the gap between the activated carbon fiber and the slow-release matrix can promote the circulation and transmission of the nitrifying bacteria growth promoter along the activated carbon fiber, and then fully contact the surface of the activated carbon fiber and the nitrifying bacteria film. Through the above method, during the domestication and biofilm formation period, the nitrifying bacteria growth promoter can be fully utilized to activate the nitrifying bacteria, so that they can grow and reproduce rapidly on the surface of the activated carbon fiber, thereby shortening the domestication and biofilm formation time; during the wastewater nitrification treatment period, the nitrifying bacteria growth promoter can be fully utilized to provide nutrients for nitrification, thereby improving the wastewater nitrification treatment efficiency.

[0013] In addition, the porogen ammonium bicarbonate used in the present invention and its products in the porogenic process will not inhibit the growth of nitrifying bacteria: ammonium bicarbonate is decomposed into carbon dioxide, ammonia and water during heat treatment to form pores and released outside the microbial carrier. Some undecomposed ammonium bicarbonate is easily soluble in water and will be taken out of the microbial carrier by water during the acclimation and biofilm formation period. A small amount of residue in the microbial carrier can help the acclimation of the microbial film on the surface of the activated carbon fiber, so that the microbial film has a higher content of nitrifying bacteria. In addition, in the porogenic process, the water-proof layer on the surface of the ammonium bicarbonate layer is destroyed, so it will not have a significant impact on the attachment of nitrifying bacteria to the surface of the activated carbon fiber.

[0014] Preferably, in step S1, the thickness of the ammonium bicarbonate layer in the modified activated carbon fiber is 5 to 10 μm.

[0015] Preferably, in step S1, the water-proof layer is an oil film, and the method for preparing the modified activated carbon fiber comprises the following steps:

[0016] (1.1) depositing ammonium bicarbonate on the surface of activated carbon fiber to obtain ammonium bicarbonate modified activated carbon fiber;

[0017] (1.2) The ammonium bicarbonate-modified activated carbon fiber is immersed in engine oil, taken out after being fully soaked, and drained to obtain modified activated carbon fiber.

[0018] Preferably, in step S1, the length of the modified activated carbon fiber is 20 to 40 mm.

[0019] Preferably, in step S1, the sustained-release matrix material comprises redispersible latex powder and inorganic aggregate.

[0020] Furthermore, in step S1, the inorganic aggregate includes silicate cement and porous clay, and the slow-release matrix material includes redispersible latex powder, silicate cement and porous clay in a mass ratio of 1:8-12:3-8.

[0021] Preferably, in step S1, the preparation method of the microbial carrier includes the following steps: mixing the sustained-release matrix material, modified activated carbon fiber, nitrifying bacteria growth promoter and water to form a slurry, injecting it into a mold, allowing it to stand and harden, and performing heat treatment to form pores during the standing and hardening period to obtain a microbial carrier.

[0022] During the static hardening process, the mechanical strength of the microbial carrier gradually increases with time. After the static hardening is completed, the mechanical strength of the microbial carrier is relatively high, and the carbon dioxide and ammonia released during the pore formation reaction are not easy to form pores in the microbial carrier (fewer pores can be formed). However, the present invention forms pores during the static hardening period, which is conducive to forming more pores in the microbial carrier by using the carbon dioxide and ammonia released during the pore formation.

[0023] Furthermore, the process of heat treatment to form pores during static hardening includes the following steps: after static hardening for 8 to 12 hours, treating at 60 to 65° C. for 60 to 80 minutes, and then static hardening for another 6 to 7 days.

[0024] Furthermore, the mass ratio of the sustained-release matrix material, the modified activated carbon fiber, the nitrifying bacteria growth promoter and water is 1:0.05-0.15:0.02-0.10:0.5-1.0.

[0025] Preferably, in step S1, 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.

[0026] Preferably, in step S1, the amount of the microbial carrier used is 1 / 3 to 1 / 2 of the volume of the biological treatment device.

[0027] Preferably, in step S1, the amount of activated sludge used is 1 / 4 to 1 / 3 of the volume of the biological treatment device.

[0028] Preferably, in step S1, the acclimation and biofilm formation process includes the following steps: diluting the ammonia nitrogen wastewater to be treated to an ammonia nitrogen concentration of 150-250 mg / L, passing it into a biological treatment device until the ammonia nitrogen concentration drops to no more than 50 mg / L; then diluting the ammonia nitrogen wastewater to be treated to an ammonia nitrogen concentration of 300-350 mg / L, passing it into a biological treatment device, and continuously inletting and outleting water for 10-15 days.

[0029] Preferably, before step S2, the ammonia nitrogen wastewater to be treated is subjected to water quality adjustment, the pH is adjusted to 7.0-8.0, and the ammonia nitrogen concentration is adjusted to no more than 500 mg / L.

[0030] Preferably, in step S2, during the nitrification treatment, the dissolved oxygen content in the ammonia nitrogen wastewater is controlled to be 3-5 mg / L, the temperature of the ammonia nitrogen wastewater is controlled to be 25-35° C., and the hydraulic retention time is 2-5 d.

[0031] Compared with the prior art, the present invention has the following advantages:

[0032] (1) In the process of microbial treatment of ammonia nitrogen wastewater, the present invention can promote the circulation of nitrifying bacteria growth promoter in the microbial carrier by using a special microbial carrier, and contact with the surface of activated carbon fiber and nitrifying bacteria membrane, thereby shortening the acclimatization and biofilm formation time and improving the wastewater nitrification treatment efficiency;

[0033] (2) In the preparation process of the microbial carrier of the present invention, pores are formed during the static hardening period, which is beneficial to form more pores in the microbial carrier by utilizing the carbon dioxide and ammonia released during the pores, thereby further improving the efficiency of domestication and biofilm formation as well as wastewater nitrification treatment. DETAILED DESCRIPTION

[0034] The present invention will be further described below in conjunction with the embodiments.

[0035] Overall embodiment

[0036] A microbial treatment method for ammonia nitrogen wastewater comprises the following steps:

[0037] Step S1: adding activated sludge and microbial carriers into a biological treatment device, and introducing acclimation water containing ammonia nitrogen to perform acclimation and biofilm formation; the raw materials of the microbial carrier include a slow-release matrix material, modified activated carbon fiber and a nitrifying bacteria growth promoter, the modified activated carbon fiber is an activated carbon fiber with an ammonium bicarbonate layer and a water-insulating layer arranged on the surface from the inside to the outside in sequence, and the microbial carrier is obtained by mixing and molding the raw materials and then subjecting them to heat treatment to form pores;

[0038] Step S2: After the completion of acclimatization and biofilm formation, the ammonia nitrogen wastewater to be treated is passed into a biological treatment device for nitrification treatment.

[0039] As a specific implementation, in step S1, the amount of the microbial carrier is 1 / 3 to 1 / 2 of the volume of the biological treatment device, and the amount of the activated sludge is 1 / 4 to 1 / 3 of the volume of the biological treatment device.

[0040] As a specific implementation, in step S1, the water-proof layer is an oil film, and the preparation method of the modified activated carbon fiber comprises the following steps:

[0041] (1.1) After the activated carbon fiber is cut into a length of 20 to 40 mm, ammonium bicarbonate is deposited on the surface thereof to form an ammonium bicarbonate layer with a thickness of 5 to 10 μm, thereby obtaining ammonium bicarbonate-modified activated carbon fiber;

[0042] (1.2) The ammonium bicarbonate-modified activated carbon fiber is immersed in engine oil, taken out after being fully soaked, and drained to obtain modified activated carbon fiber.

[0043] As a specific implementation, in step S1, the sustained-release matrix material includes redispersible latex powder, silicate cement and porous clay in a mass ratio of 1:8-12:3-8; the preparation method of the microbial carrier includes the following steps: mixing the sustained-release matrix material, modified activated carbon fiber, nitrifying bacteria growth promoter and water in a mass ratio of 1:0.05-0.15:0.02-0.10:0.5-1.0 to form a slurry, injecting it into a mold, and after standing and hardening for 8-12 hours, treating it at 60-65°C for 60-80 minutes, and then standing and hardening for 6-7 days to obtain a microbial carrier.

[0044] As a specific implementation, in step S1, 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.

[0045] As a specific implementation method, in step S1, the acclimation and biofilm formation process includes the following steps: diluting the ammonia nitrogen wastewater to be treated to an ammonia nitrogen concentration of 150 to 250 mg / L, passing it into a biological treatment device until the ammonia nitrogen concentration drops to no more than 50 mg / L; then diluting the ammonia nitrogen wastewater to be treated to an ammonia nitrogen concentration of 300 to 350 mg / L, passing it into a biological treatment device, and continuously inletting and outleting water for 10 to 15 days.

[0046] As a specific implementation method, before step S2, the ammonia nitrogen wastewater to be treated is subjected to water quality adjustment, the pH is adjusted to 7.0-8.0, and the ammonia nitrogen concentration is adjusted to no more than 500 mg / L.

[0047] As a specific implementation, in step S2, during the nitrification treatment, the dissolved oxygen content in the ammonia nitrogen wastewater is controlled to be 3-5 mg / L, the temperature of the ammonia nitrogen wastewater is controlled to be 25-35°C, and the hydraulic retention time is 2-5 days.

[0048] Example 1

[0049] The microbial carrier is prepared by the following steps:

[0050] (1) Preparation of modified activated carbon fibers:

[0051] (1.1) After the activated carbon fiber is cut into a length of 30±5 mm, ammonium bicarbonate is deposited on the surface of the activated carbon fiber by atomization deposition method to form an ammonium bicarbonate layer with an average thickness of 5.4 μm, thereby obtaining an ammonium bicarbonate-modified activated carbon fiber, wherein the mass ratio of ammonium bicarbonate to the activated carbon fiber is 0.38:1;

[0052] (1.2) The ammonium bicarbonate-modified activated carbon fiber is immersed in engine oil, taken out after soaking for 5 minutes, and drained to obtain modified activated carbon fiber.

[0053] (2) Preparation of nitrifying bacteria growth promoter:

[0054] (2.1) 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;

[0055] (2.2) All raw materials are separated into granules and lumps using a FAST-600 single-layer rotary vibrating screen with a mesh size of 30. Granules can be used directly, while lumps need to be broken into granules by a pulverizer before use;

[0056] (2.3) All the raw materials processed in step (2.2) are mixed evenly using a mixer to obtain a nitrifying bacteria growth promoter.

[0057] (3) Preparation of microbial carriers:

[0058] (3.1) Weigh by weight: 1 part of redispersible latex powder, 10 parts of Portland cement, 5 parts of attapulgite, 0.8 parts of modified activated carbon fiber, 1.6 parts of nitrifying bacteria growth promoter, and 6.5 parts of water;

[0059] (3.2) After all the raw materials are mixed to form a slurry, it is injected into a rectangular mold with an internal size of 6 cm×2 cm×2 cm. After being allowed to stand and harden at room temperature for 10 hours, it is heated to 65°C and kept warm for 60 minutes. It is then allowed to stand and harden at room temperature for 7 days (during this period, water is sprayed on the surface, and the amount of water sprayed is 1.5% of the mass of the microbial carrier) to obtain a microbial carrier.

[0060] Take ammonia nitrogen wastewater from a chemical plant in Zhejiang Province. After measurement, its COD is 1730 mg / L and the ammonia nitrogen concentration is 568 mg / L. Use the microbial carrier prepared in this example to treat the ammonia nitrogen wastewater with microorganisms. The specific steps are as follows:

[0061] Step S1: loading activated sludge with a volume of 1 / 4 of the volume of the aerobic tank into the aerobic tank, and then loading microbial carrier with a volume of 1 / 3 of the volume of the aerobic tank;

[0062] Step S2: domestication and biofilm formation are carried out by gradually increasing the ammonia nitrogen load, specifically as follows: diluting the ammonia nitrogen wastewater to an ammonia nitrogen concentration of 189 mg / L, adjusting the pH to 7.5, and then passing it into the aerobic tank. The passing is stopped after the aerobic tank volume reaches 3 / 4, and the dissolved oxygen content in the wastewater is controlled to 4.5±0.5 mg / L by aeration, and the water temperature is controlled to 30±1°C. The ammonia nitrogen concentration in the wastewater in the aerobic tank is detected at regular intervals. The ammonia nitrogen concentration is measured to drop to 48 mg / L 72 hours after the wastewater is passed, and the wastewater is discharged; The nitrogen wastewater was diluted to an ammonia nitrogen concentration of 315 mg / L, and the pH was adjusted to 7.5, and then passed into the aerobic tank, and the dissolved oxygen content in the wastewater was controlled to 4.5±0.5 mg / L by aeration, and the water temperature was controlled to 30±1°C, and the water was continuously in and out for 10 hours; Step S3: The ammonia nitrogen wastewater was diluted to an ammonia nitrogen concentration of 379 mg / L, and the pH was adjusted to 7.5, and then passed into the aerobic tank, and the dissolved oxygen content in the wastewater was controlled to 4.5±0.5 mg / L by aeration, and the water temperature was controlled to 30±1°C, and the hydraulic retention time was 5 days. The operation was continuous for 30 days, during which the ammonia nitrogen content in the effluent of the aerobic tank was continuously monitored, and the ammonia nitrogen concentration in the effluent was ≤13.7 mg / L, and the ammonia nitrogen removal rate was calculated to be >96.3%.

[0063] Example 2

[0064] The microbial carrier is prepared by the following steps:

[0065] (1) Preparation of modified activated carbon fibers:

[0066] (1.1) After the activated carbon fiber is cut into a length of 30±5 mm, ammonium bicarbonate is deposited on the surface of the activated carbon fiber by an atomization deposition method to form an ammonium bicarbonate layer with an average thickness of 9.6 μm, thereby obtaining an ammonium bicarbonate-modified activated carbon fiber, wherein the mass ratio of ammonium bicarbonate to the activated carbon fiber is 0.69:1;

[0067] (1.2) The ammonium bicarbonate-modified activated carbon fiber is immersed in engine oil, taken out after soaking for 5 minutes, and drained to obtain modified activated carbon fiber.

[0068] (2) Preparation of nitrifying bacteria growth promoter:

[0069] (2.1) 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;

[0070] (2.2) All raw materials are separated into granules and lumps using a FAST-600 single-layer rotary vibrating screen with a mesh size of 30. Granules can be used directly, while lumps need to be broken into granules by a pulverizer before use;

[0071] (2.3) All the raw materials processed in step (2.2) are mixed evenly using a mixer to obtain a nitrifying bacteria growth promoter.

[0072] (3) Preparation of microbial carriers:

[0073] (3.1) Weigh by weight: 1 part of redispersible latex powder, 8 parts of Portland cement, 3 parts of attapulgite, 1.8 parts of modified activated carbon fiber, 0.24 parts of nitrifying bacteria growth promoter, and 12 parts of water;

[0074] (3.2) After all the raw materials are mixed to form a slurry, it is injected into a rectangular mold with an internal size of 6 cm×2 cm×2 cm. After being allowed to stand and harden at room temperature for 12 hours, it is heated to 60°C and kept warm for 80 minutes. It is then allowed to stand and harden at room temperature for another 6 days (during which time water is sprayed on the surface, and the amount of water sprayed is 1.5% of the mass of the microbial carrier) to obtain a microbial carrier.

[0075] The microbial carrier prepared in this example was used to perform microbial treatment on the same ammonia nitrogen wastewater as in Example 1. The specific steps are as follows:

[0076] Step S1: loading activated sludge with a volume of 1 / 4 of the volume of the aerobic tank into the aerobic tank, and then loading microbial carrier with a volume of 1 / 3 of the volume of the aerobic tank;

[0077] Step S2: domestication and biofilm formation are carried out by gradually increasing the ammonia nitrogen load, specifically as follows: diluting the ammonia nitrogen wastewater to an ammonia nitrogen concentration of 189 mg / L, adjusting the pH to 7.5, and then passing it into the aerobic tank. The passing is stopped after the aerobic tank volume reaches 3 / 4, and the dissolved oxygen content in the wastewater is controlled to 4.5±0.5 mg / L by aeration, and the water temperature is controlled to 30±1°C. The ammonia nitrogen concentration in the wastewater in the aerobic tank is detected at regular intervals. The ammonia nitrogen concentration is measured to drop to 44 mg / L 72 hours after the wastewater is passed, and the wastewater is discharged; The nitrogen wastewater was diluted to an ammonia nitrogen concentration of 315 mg / L, and the pH was adjusted to 7.5, and then passed into the aerobic tank, and the dissolved oxygen content in the wastewater was controlled to 4.5±0.5 mg / L by aeration, and the water temperature was controlled to 30±1°C, and the water was continuously in and out for 10 hours; Step S3: The ammonia nitrogen wastewater was diluted to an ammonia nitrogen concentration of 379 mg / L, and the pH was adjusted to 7.5, and then passed into the aerobic tank, and the dissolved oxygen content in the wastewater was controlled to 4.5±0.5 mg / L by aeration, and the water temperature was controlled to 30±1°C, and the hydraulic retention time was 3 days. The operation was continuous for 30 days, during which the ammonia nitrogen content in the effluent of the aerobic tank was continuously monitored, and the ammonia nitrogen concentration in the effluent was ≤19.5 mg / L, and the ammonia nitrogen removal rate was calculated to be >94.8%.

[0078] Example 3

[0079] The microbial carrier is prepared by the following steps:

[0080] (1) Preparation of modified activated carbon fibers:

[0081] (1.1) After the activated carbon fiber is cut into a length of 30±5 mm, ammonium bicarbonate is deposited on the surface of the activated carbon fiber by atomization deposition to form an ammonium bicarbonate layer with an average thickness of 7.3 μm, thereby obtaining an ammonium bicarbonate-modified activated carbon fiber, wherein the mass ratio of ammonium bicarbonate to the activated carbon fiber is 0.52:1;

[0082] (1.2) The ammonium bicarbonate-modified activated carbon fiber is immersed in engine oil, taken out after soaking for 5 minutes, and drained to obtain modified activated carbon fiber.

[0083] (2) Preparation of nitrifying bacteria growth promoter:

[0084] (2.1) 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;

[0085] (2.2) All raw materials are separated into granules and lumps using a FAST-600 single-layer rotary vibrating screen with a mesh size of 30. Granules can be used directly, while lumps need to be broken into granules by a pulverizer before use;

[0086] (2.3) All the raw materials processed in step (2.2) are mixed evenly using a mixer to obtain a nitrifying bacteria growth promoter.

[0087] (3) Preparation of microbial carriers:

[0088] (3.1) Weigh by weight: 1 part of redispersible latex powder, 12 parts of Portland cement, 3 parts of attapulgite, 2 parts of modified activated carbon fiber, 1.3 parts of nitrifying bacteria growth promoter, and 8 parts of water;

[0089] (3.2) After all the raw materials are mixed to form a slurry, it is injected into a rectangular mold with an internal size of 6 cm×2 cm×2 cm. After being allowed to stand and harden at room temperature for 8 hours, it is heated to 65°C and kept warm for 70 minutes. It is then allowed to stand and harden at room temperature for another 7 days (during which time water is sprayed on the surface, and the amount of water sprayed is 1.5% of the mass of the microbial carrier) to obtain a microbial carrier.

[0090] The microbial carrier prepared in this example was used to perform microbial treatment on the same ammonia nitrogen wastewater as in Example 1. The specific steps are as follows:

[0091] Step S1: loading activated sludge with a volume of 1 / 4 of the volume of the aerobic tank into the aerobic tank, and then loading microbial carrier with a volume of 1 / 3 of the volume of the aerobic tank;

[0092] Step S2: domestication and biofilm formation are carried out by gradually increasing the ammonia nitrogen load, specifically as follows: diluting the ammonia nitrogen wastewater to an ammonia nitrogen concentration of 189 mg / L, adjusting the pH to 7.5, and then passing it into the aerobic tank. The passing is stopped after the aerobic tank volume reaches 3 / 4, and the dissolved oxygen content in the wastewater is controlled to 4.5±0.5 mg / L by aeration, and the water temperature is controlled to 30±1°C. The ammonia nitrogen concentration in the wastewater in the aerobic tank is detected at regular intervals. The ammonia nitrogen concentration is measured to drop to 37 mg / L 72 hours after the wastewater is passed, and the wastewater is discharged; The nitrogen wastewater was diluted to an ammonia nitrogen concentration of 315 mg / L, and the pH was adjusted to 7.5, and then passed into the aerobic tank, and the dissolved oxygen content in the wastewater was controlled to 4.5±0.5 mg / L by aeration, and the water temperature was controlled to 30±1°C, and the water was continuously in and out for 10 hours; Step S3: The ammonia nitrogen wastewater was diluted to an ammonia nitrogen concentration of 379 mg / L, and the pH was adjusted to 7.5, and then passed into the aerobic tank, and the dissolved oxygen content in the wastewater was controlled to 4.5±0.5 mg / L by aeration, and the water temperature was controlled to 30±1°C, and the hydraulic retention time was 2 days. The operation was continuous for 30 days, during which the ammonia nitrogen content in the effluent of the aerobic tank was continuously monitored, and the ammonia nitrogen concentration in the effluent was ≤14.4 mg / L, and the ammonia nitrogen removal rate was calculated to be >96.2%.

[0093] Example 4

[0094] The microbial carrier is prepared by the following steps:

[0095] (1) Preparation of modified activated carbon fibers:

[0096] (1.1) After the activated carbon fiber is cut into a length of 30±5 mm, ammonium bicarbonate is deposited on the surface of the activated carbon fiber by atomization deposition to form an ammonium bicarbonate layer with an average thickness of 7.3 μm, thereby obtaining an ammonium bicarbonate-modified activated carbon fiber, wherein the mass ratio of ammonium bicarbonate to the activated carbon fiber is 0.52:1;

[0097] (1.2) The ammonium bicarbonate-modified activated carbon fiber is immersed in engine oil, taken out after soaking for 5 minutes, and drained to obtain modified activated carbon fiber.

[0098] (2) Preparation of nitrifying bacteria growth promoter:

[0099] (2.1) 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;

[0100] (2.2) All raw materials are separated into granules and lumps using a FAST-600 single-layer rotary vibrating screen with a mesh size of 30. Granules can be used directly, while lumps need to be broken into granules by a pulverizer before use;

[0101] (2.3) All the raw materials processed in step (2.2) are mixed evenly using a mixer to obtain a nitrifying bacteria growth promoter.

[0102] (3) Preparation of microbial carriers:

[0103] (3.1) Weigh by weight: 1 part of redispersible latex powder, 12 parts of Portland cement, 3 parts of attapulgite, 2 parts of modified activated carbon fiber, 1.3 parts of nitrifying bacteria growth promoter, and 8 parts of water;

[0104] (3.2) After all the raw materials are mixed to form a slurry, it is injected into a rectangular mold with an internal size of 6 cm×2 cm×2 cm. After being allowed to stand and harden at room temperature for 8 hours, it is continued to stand and harden for 7 days (during this period, water is sprayed on the surface, and the amount of water sprayed is 1.5% of the mass of the microbial carrier), and then heated to 65°C and kept warm for 70 minutes to obtain a microbial carrier.

[0105] The microbial carrier prepared in this example was used to perform microbial treatment on the same ammonia nitrogen wastewater as in Example 1. The specific steps are as follows:

[0106] Step S1: loading activated sludge with a volume of 1 / 4 of the volume of the aerobic tank into the aerobic tank, and then loading microbial carrier with a volume of 1 / 3 of the volume of the aerobic tank;

[0107] Step S2: domestication and biofilm formation are carried out by gradually increasing the ammonia nitrogen load, specifically as follows: diluting the ammonia nitrogen wastewater to an ammonia nitrogen concentration of 189 mg / L, adjusting the pH to 7.5, and then passing it into the aerobic tank. The passing is stopped after the aerobic tank volume reaches 3 / 4, and the dissolved oxygen content in the wastewater is controlled to 4.5±0.5 mg / L by aeration, and the water temperature is controlled to 30±1°C. The ammonia nitrogen concentration in the wastewater in the aerobic tank is detected at regular intervals. 90 hours after the wastewater is passed, the ammonia nitrogen concentration is measured to drop to 38 mg / L, and the wastewater is discharged; The nitrogen wastewater was diluted to an ammonia nitrogen concentration of 315 mg / L, and the pH was adjusted to 7.5, and then passed into the aerobic tank, and the dissolved oxygen content in the wastewater was controlled to 4.5±0.5 mg / L by aeration, and the water temperature was controlled to 30±1°C, and the water was continuously in and out for 10 hours; Step S3: The ammonia nitrogen wastewater was diluted to an ammonia nitrogen concentration of 379 mg / L, and the pH was adjusted to 7.5, and then passed into the aerobic tank, and the dissolved oxygen content in the wastewater was controlled to 4.5±0.5 mg / L by aeration, and the water temperature was controlled to 30±1°C, and the hydraulic retention time was 2 days. The operation was continuous for 30 days, during which the ammonia nitrogen content in the effluent of the aerobic tank was continuously monitored, and the ammonia nitrogen concentration in the effluent was ≤62.2 mg / L, and the ammonia nitrogen removal rate was calculated to be >83.5%.

[0108] Analysis of ammonia nitrogen removal effect: In the microbial treatment of ammonia nitrogen wastewater, the ammonia nitrogen removal rate of Example 3 is significantly higher than that of Example 4; and during the first stage of acclimation and biofilm formation, the time for the ammonia nitrogen concentration to drop from 189 mg / L to about 37 mg / L in Example 3 is shorter than that in Example 4. This indicates that in the process of preparing microbial carriers, compared with performing pore formation after static hardening, performing pore formation during static hardening can improve the ammonia nitrogen removal effect in wastewater and accelerate the acclimation and biofilm formation speed. The reason is that after the static hardening is completed, the mechanical strength of the microbial carrier is relatively high, so the carbon dioxide and ammonia released during the pore-forming reaction form fewer pores in the microbial carrier; while pore-forming during the static hardening period is beneficial to the use of the carbon dioxide and ammonia released during the pore-forming reaction to form more pores in the microbial carrier and expand the gap between the activated carbon fiber and the slow-release matrix, thereby promoting the nitrifying bacteria growth promoter released from the slow-release matrix to a greater extent. Contact with the nitrifying bacteria film attached to the surface of the activated carbon fiber, thereby promoting the rapid growth and reproduction of nitrifying bacteria on the surface of the activated carbon fiber, and promoting its nitrification.

[0109] Comparative Example 1

[0110] The microbial carrier is prepared by the following steps:

[0111] (1) Preparation of nitrifying bacteria growth promoter:

[0112] (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;

[0113] (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;

[0114] (1.3) All the raw materials processed in step (1.2) are mixed evenly using a mixer to obtain a nitrifying bacteria growth promoter.

[0115] (2) Preparation of microbial carriers:

[0116] (2.1) Weigh by weight: 1 part of redispersible latex powder, 12 parts of Portland cement, 3 parts of attapulgite, 1.3 parts of activated carbon fiber, 0.7 parts of ammonium bicarbonate, 1.3 parts of nitrifying bacteria growth promoter, and 8 parts of water;

[0117] (2.2) After all the raw materials are mixed to form a slurry, it is injected into a rectangular mold with an internal size of 6 cm×2 cm×2 cm. After being allowed to stand and harden at room temperature for 8 hours, it is heated to 65°C and kept warm for 70 minutes. It is then allowed to stand and harden at room temperature for another 7 days (during which time, water is sprayed on the surface, and the amount of water sprayed is 1.5% of the mass of the microbial carrier) to obtain a microbial carrier.

[0118] The microbial carrier prepared in this example was used to perform microbial treatment on the same ammonia nitrogen wastewater as in Example 1. The specific steps are as follows:

[0119] Step S1: loading activated sludge with a volume of 1 / 4 of the volume of the aerobic tank into the aerobic tank, and then loading microbial carrier with a volume of 1 / 3 of the volume of the aerobic tank;

[0120] Step S2: domestication and biofilm formation are carried out by gradually increasing the ammonia nitrogen load, specifically as follows: diluting the ammonia nitrogen wastewater to an ammonia nitrogen concentration of 189 mg / L, adjusting the pH to 7.5, and then passing it into the aerobic tank. The passing is stopped after the aerobic tank volume reaches 3 / 4, and the dissolved oxygen content in the wastewater is controlled to 4.5±0.5 mg / L by aeration, and the water temperature is controlled to 30±1°C. The ammonia nitrogen concentration in the wastewater in the aerobic tank is detected at regular intervals. When the ammonia nitrogen concentration is measured to drop to 40 mg / L 132 hours after the wastewater is passed, the wastewater is discharged; The ammonia nitrogen wastewater was diluted to an ammonia nitrogen concentration of 315 mg / L, and the pH was adjusted to 7.5, and then passed into the aerobic tank, and the dissolved oxygen content in the wastewater was controlled to 4.5±0.5 mg / L by aeration, and the water temperature was controlled to 30±1°C, and the water was continuously in and out for 10 hours; Step S3: The ammonia nitrogen wastewater was diluted to an ammonia nitrogen concentration of 379 mg / L, and the pH was adjusted to 7.5, and then passed into the aerobic tank, and the dissolved oxygen content in the wastewater was controlled to 4.5±0.5 mg / L by aeration, and the water temperature was controlled to 30±1°C, and the hydraulic retention time was 2 days. The operation was continuous for 30 days, during which the ammonia nitrogen content in the effluent of the aerobic tank was continuously monitored, and the ammonia nitrogen concentration in the effluent was ≤119.8 mg / L, and the ammonia nitrogen removal rate was calculated to be >68.3%.

[0121] Comparative Example 2

[0122] The microbial carrier is prepared by the following steps:

[0123] (1) Preparation of modified activated carbon fibers:

[0124] (1.1) After the activated carbon fiber is cut into a length of 30±5 mm, ammonium bicarbonate is deposited on the surface of the activated carbon fiber by atomization deposition to form an ammonium bicarbonate layer with an average thickness of 7.3 μm, thereby obtaining an ammonium bicarbonate-modified activated carbon fiber, wherein the mass ratio of ammonium bicarbonate to the activated carbon fiber is 0.52:1;

[0125] (1.2) The ammonium bicarbonate-modified activated carbon fiber is immersed in engine oil, taken out after soaking for 5 minutes, and drained to obtain modified activated carbon fiber.

[0126] (2) Preparation of nitrifying bacteria growth promoter:

[0127] (2.1) 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;

[0128] (2.2) All raw materials are separated into granules and lumps using a FAST-600 single-layer rotary vibrating screen with a mesh size of 30. Granules can be used directly, while lumps need to be broken into granules by a pulverizer before use;

[0129] (2.3) All the raw materials processed in step (2.2) are mixed evenly using a mixer to obtain a nitrifying bacteria growth promoter.

[0130] (3) Preparation of microbial carriers:

[0131] (3.1) Weigh by weight: 1 part of redispersible latex powder, 12 parts of Portland cement, 3 parts of attapulgite, 2 parts of modified activated carbon fiber, 1.3 parts of nitrifying bacteria growth promoter, and 8 parts of water;

[0132] (3.2) After all the raw materials are mixed to form a slurry, it is injected into a rectangular mold with an internal size of 6 cm×2 cm×2 cm. After being allowed to stand and harden at room temperature for 8 hours, it is continued to stand and harden for 7 days (during this period, water is sprayed on the surface, and the amount of water sprayed is 1.5% of the mass of the microbial carrier), and then heated to 65°C and kept warm for 70 minutes to obtain a microbial carrier.

[0133] The microbial carrier prepared in this example was used to perform microbial treatment on the same ammonia nitrogen wastewater as in Example 1. The specific steps are as follows:

[0134] Step S1: loading activated sludge with a volume of 1 / 4 of the volume of the aerobic tank into the aerobic tank, and then loading microbial carrier with a volume of 1 / 3 of the volume of the aerobic tank;

[0135] Step S2: domestication and biofilm formation are carried out by gradually increasing the ammonia nitrogen load, specifically as follows: diluting the ammonia nitrogen wastewater to an ammonia nitrogen concentration of 189 mg / L, adjusting the pH to 7.5, and then passing it into the aerobic tank. The passing is stopped after the aerobic tank volume reaches 3 / 4, and the dissolved oxygen content in the wastewater is controlled to 4.5±0.5 mg / L by aeration, and the water temperature is controlled to 30±1°C. The ammonia nitrogen concentration in the wastewater in the aerobic tank is detected at regular intervals. The ammonia nitrogen concentration is measured to drop to 38 mg / L 124 hours after the wastewater is passed, and the wastewater is discharged; The ammonia nitrogen wastewater was diluted to an ammonia nitrogen concentration of 315 mg / L, and the pH was adjusted to 7.5, and then passed into the aerobic tank, and the dissolved oxygen content in the wastewater was controlled to 4.5±0.5 mg / L by aeration, and the water temperature was controlled to 30±1°C, and the water was continuously in and out for 10 hours; Step S3: The ammonia nitrogen wastewater was diluted to an ammonia nitrogen concentration of 379 mg / L, and the pH was adjusted to 7.5, and then passed into the aerobic tank, and the dissolved oxygen content in the wastewater was controlled to 4.5±0.5 mg / L by aeration, and the water temperature was controlled to 30±1°C, and the hydraulic retention time was 2 days. The operation was continuous for 30 days, during which the ammonia nitrogen content in the effluent of the aerobic tank was continuously monitored, and the ammonia nitrogen concentration in the effluent was ≤97.5 mg / L, and the ammonia nitrogen removal rate was calculated to be >74.2%.

[0136] Analysis of ammonia nitrogen removal effect: In the microbial treatment of ammonia nitrogen wastewater, the ammonia nitrogen removal rate of Example 3 is significantly higher than that of Comparative Examples 1 and 2; and, in the first stage of domestication and biofilm formation, the time required for Example 3 is significantly shorter than that of Comparative Examples 1 and 2. It is explained that in the process of preparing the microbial carrier, compared with not adding activated carbon fiber and only adding ammonium bicarbonate, and compared with dispersed addition of activated carbon fiber and ammonium bicarbonate, by setting an ammonium bicarbonate layer on the surface of the activated carbon fiber, the ammonia nitrogen removal effect in the wastewater can be improved, and the domestication and biofilm formation speed can be accelerated. The reason is that by using the ammonium bicarbonate pores on the surface of the activated carbon fiber, a gap can be formed between the fiber and the slow-release matrix, and a channel connecting the surface of the activated carbon fiber and the outside of the slow-release matrix can be formed in the slow-release matrix. In this way, during domestication and biofilm formation, the nitrifying bacteria growth promoter can be fully utilized to activate the nitrifying bacteria, so that it can grow and reproduce rapidly on the surface of the activated carbon fiber, thereby shortening the domestication and biofilm formation time; during the nitrification treatment of wastewater, the nitrifying bacteria growth promoter can be fully utilized to provide nutrition for nitrification, thereby improving the nitrification treatment efficiency of wastewater.

[0137] Comparative Example 3

[0138] The microbial carrier is prepared by the following steps:

[0139] (1) Preparation of modified activated carbon fibers:

[0140] After the activated carbon fibers were cut into a length of 30±5 mm, ammonium bicarbonate was deposited on the surface thereof by an atomization deposition method to form an ammonium bicarbonate layer with an average thickness of 7.3 μm, thereby obtaining modified activated carbon fibers, wherein the mass ratio of ammonium bicarbonate to activated carbon fibers was 0.52:1.

[0141] (2) Preparation of nitrifying bacteria growth promoter:

[0142] (2.1) 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;

[0143] (2.2) All raw materials are separated into granules and lumps using a FAST-600 single-layer rotary vibrating screen with a mesh size of 30. Granules can be used directly, while lumps need to be broken into granules by a pulverizer before use;

[0144] (2.3) All the raw materials processed in step (2.2) are mixed evenly using a mixer to obtain a nitrifying bacteria growth promoter.

[0145] (3) Preparation of microbial carriers:

[0146] (3.1) Weigh by weight: 1 part of redispersible latex powder, 12 parts of Portland cement, 3 parts of attapulgite, 2 parts of modified activated carbon fiber, 1.3 parts of nitrifying bacteria growth promoter, and 8 parts of water;

[0147] (3.2) After all the raw materials are mixed to form a slurry, it is injected into a rectangular mold with an internal size of 6 cm×2 cm×2 cm. After being allowed to stand and harden at room temperature for 8 hours, it is heated to 65°C and kept warm for 70 minutes. It is then allowed to stand and harden at room temperature for another 7 days (during which time water is sprayed on the surface, and the amount of water sprayed is 1.5% of the mass of the microbial carrier) to obtain a microbial carrier.

[0148] The microbial carrier prepared in this example was used to perform microbial treatment on the same ammonia nitrogen wastewater as in Example 1. The specific steps are as follows:

[0149] Step S1: loading activated sludge with a volume of 1 / 4 of the volume of the aerobic tank into the aerobic tank, and then loading microbial carrier with a volume of 1 / 3 of the volume of the aerobic tank;

[0150] Step S2: domestication and biofilm formation are carried out by gradually increasing the ammonia nitrogen load, specifically as follows: diluting the ammonia nitrogen wastewater to an ammonia nitrogen concentration of 189 mg / L, adjusting the pH to 7.5, and then passing it into the aerobic tank. The passing is stopped after the aerobic tank has reached 3 / 4 of the volume. The dissolved oxygen content in the wastewater is controlled to 4.5±0.5 mg / L by aeration, and the water temperature is controlled to 30±1°C. The ammonia nitrogen concentration in the wastewater in the aerobic tank is detected at regular intervals. The ammonia nitrogen concentration is measured to drop to 46 mg / L 124 hours after the wastewater is passed, and the wastewater is discharged; The ammonia nitrogen wastewater was diluted to an ammonia nitrogen concentration of 315 mg / L, and the pH was adjusted to 7.5, and then passed into the aerobic tank, and the dissolved oxygen content in the wastewater was controlled to 4.5±0.5 mg / L by aeration, and the water temperature was controlled to 30±1°C, and the water was continuously in and out for 10 hours; Step S3: The ammonia nitrogen wastewater was diluted to an ammonia nitrogen concentration of 379 mg / L, and the pH was adjusted to 7.5, and then passed into the aerobic tank, and the dissolved oxygen content in the wastewater was controlled to 4.5±0.5 mg / L by aeration, and the water temperature was controlled to 30±1°C, and the hydraulic retention time was 2 days. The operation was continuous for 30 days, during which the ammonia nitrogen content in the effluent of the aerobic tank was continuously monitored, and the ammonia nitrogen concentration in the effluent was ≤93.6 mg / L, and the ammonia nitrogen removal rate was calculated to be >75.3%.

[0151] Analysis of ammonia nitrogen removal effect: In the microbial treatment of ammonia nitrogen wastewater, the ammonia nitrogen removal rate of Example 3 is significantly higher than that of Comparative Example 3; and, in the first stage of acclimatization and biofilm formation, the time required for Example 3 is significantly shorter than that of Comparative Example 3. It is explained that in the process of preparing the microbial carrier, by providing an engine oil film on the outermost layer of the modified activated carbon fiber, the ammonia nitrogen removal effect in the wastewater can be improved, and the acclimatization and biofilm formation speed can be accelerated. The reason is that in the process of mixing and molding the microbial carrier, the engine oil film can prevent the ammonium bicarbonate layer from dissolving into the water, so that it can play the role of "forming a gap between the fiber and the sustained-release matrix" and "forming a pore in the sustained-release matrix that connects the surface of the activated carbon fiber and the outside of the sustained-release matrix" when forming pores.

[0152] 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.

[0153] 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 treating ammonia nitrogen wastewater with microorganisms, characterized in that: The following steps are involved: Step S1: adding activated sludge and microbial carriers into a biological treatment device, and introducing acclimation water containing ammonia nitrogen to perform acclimation and biofilm formation; the raw materials of the microbial carrier include a slow-release matrix material, modified activated carbon fiber and a nitrifying bacteria growth promoter, the modified activated carbon fiber is an activated carbon fiber with an ammonium bicarbonate layer and a water-proof layer arranged on the surface from the inside to the outside in sequence, the microbial carrier is obtained by mixing and molding various raw materials, and then heat-treating the ammonium bicarbonate to decompose and form pores, and the water-proof layer is an engine oil film; Step S2: After the completion of acclimatization and biofilm formation, the ammonia nitrogen wastewater to be treated is passed into a biological treatment device for nitrification treatment.

2. The microbial treatment method for ammonia nitrogen wastewater according to claim 1, characterized in that: In step S1, in the modified activated carbon fiber, the thickness of the ammonium bicarbonate layer is 5-10 μm.

3. The microbial treatment method for ammonia nitrogen wastewater according to claim 1 or 2, characterized in that: In step S1, the method for preparing the modified activated carbon fiber comprises the following steps: (1.1) Depositing ammonium bicarbonate on the surface of activated carbon fiber to obtain ammonium bicarbonate modified activated carbon fiber; (1.2) Immerse the ammonium bicarbonate-modified activated carbon fiber in engine oil, take it out after it is fully soaked, drain it, and obtain modified activated carbon fiber.

4. The microbial treatment method for ammonia nitrogen wastewater according to claim 1, characterized in that: In step S1, the sustained-release matrix material includes redispersible latex powder and inorganic aggregate.

5. The microbial treatment method for ammonia nitrogen wastewater according to claim 4, characterized in that: In step S1, the inorganic aggregate includes silicate cement and porous clay, and the slow-release matrix material includes redispersible latex powder, silicate cement and porous clay in a mass ratio of 1:8-12:3-8.

6. The microbial treatment method for ammonia nitrogen wastewater according to claim 4 or 5, characterized in that: In step S1, the preparation method of the microbial carrier includes the following steps: mixing the sustained-release matrix material, modified activated carbon fiber, nitrifying bacteria growth promoter and water to form a slurry, injecting it into a mold, allowing it to stand and harden, and performing heat treatment to form pores during the standing and hardening period to obtain a microbial carrier.

7. The microbial treatment method for ammonia nitrogen wastewater according to claim 6, characterized in that: The process of heat treatment to form pores during static hardening includes the following steps: after static hardening for 8 to 12 hours, treating at 60 to 65° C. for 60 to 80 minutes, and then static hardening for another 6 to 7 days.

8. The microbial treatment method for ammonia nitrogen wastewater according to claim 1, characterized in that: In step S1, the acclimation and biofilm formation process includes the following steps: diluting the ammonia nitrogen wastewater to be treated to an ammonia nitrogen concentration of 150-250 mg / L, passing it into a biological treatment device until the ammonia nitrogen concentration drops to no more than 50 mg / L; then diluting the ammonia nitrogen wastewater to be treated to an ammonia nitrogen concentration of 300-350 mg / L, passing it into a biological treatment device, and continuously inletting and outleting water for 10-15 days.

9. The microbial treatment method for ammonia nitrogen wastewater according to claim 1 or 8, characterized in that: Before step S2, the ammonia nitrogen wastewater to be treated is subjected to water quality adjustment, the pH is adjusted to 7.0-8.0, and the ammonia nitrogen concentration is adjusted to no more than 500 mg / L.

10. The microbial treatment method for ammonia nitrogen wastewater according to claim 1, characterized in that: In step S2, during the nitrification treatment, the dissolved oxygen content in the ammonia nitrogen wastewater is controlled to be 3-5 mg / L, the temperature of the ammonia nitrogen wastewater is controlled to be 25-35° C., and the hydraulic retention time is 2-5 d.