Method for short-cut nitrification of ammonia-nitrogen wastewater and application

Abstract

The present application relates to sewage biological treatment technical field, provide a kind of ammonia nitrogen wastewater short path nitrification method and application.The method includes: S100, mature autotrophic short path nitrification sludge is inoculated into reactor, and first mixed liquor is obtained;S200, water containing ammonium salt, bicarbonate and phosphate is transported into reactor by water inlet pump;S300, first mixed liquor is mixed with water by stirrer, and aeration reaction is carried out, and second mixed liquor is obtained;S400, stop stirring, aeration and pH control to second mixed liquor, carry out solid-liquid separation, and obtain treated water and sludge;S500, enable water pump, and treated water is uniformly discharged;S600, repeat steps S200-S500, add cerium chloride solution, and carry out long-term operation.The present application uses low concentration cerium to selectively enrich endogenous heterotrophic nitrosobacteria, and cooperates with autotrophic nitrosobacteria by cerium ion, to improve the accumulation rate of nitrite.

Description

Technical Field

[0001] This invention relates to the field of wastewater biological treatment technology, and more specifically, to a method and application of short-cut nitrification of ammonia nitrogen wastewater. Background Technology

[0002] Cerium is the most abundant rare earth element in global soils and a major component of tailings from ion-adsorption rare earth mining. Due to its unique redox properties, cerium is widely used in pigments, catalysts, ceramics, alloys, optics, coatings, and medical fields. Furthermore, cerium is used as a safe and economical feed additive to replace antibiotics in promoting poultry growth and increasing egg production.

[0003] With socio-economic development, the discharge of low C / N ratio ammonia nitrogen wastewater, such as aquaculture wastewater, domestic sewage, and landfill leachate, is continuously increasing. Nitrification-denitrification is a commonly used treatment method, but its high operating costs are due to rapid consumption of organic carbon sources and high aeration energy consumption. In contrast, short-cut nitrification / anaerobic ammonia oxidation (Anammox) technology, as a novel autotrophic nitrogen removal technology, offers advantages such as low energy consumption, no need for external organic carbon sources, significantly lower costs, and a stable supply of nitrite, thus supporting the implementation of the PN / Anammox process.

[0004] However, in long-term operation, short-cut nitrification processes are prone to problems such as nitrogen loss, nitrite reduction, and N2O emissions due to the accumulation of extracellular polymers. N2O is a strong greenhouse gas, with a greenhouse effect far exceeding that of carbon dioxide and methane. Furthermore, the reduction in nitrite means a greater need for oxygen and ammonia nitrogen oxidation, thus increasing aeration energy consumption. In the PN process, the decomposition products of extracellular polymers are mainly propionic acid-type small-molecule organic compounds, which is unfavorable for heterotrophic nitrifying bacteria to accumulate nitrite.

[0005] Therefore, there is an urgent need for a technology that can improve the processing capacity of short-cut nitration processes while maintaining low energy consumption and low cost. Summary of the Invention

[0006] This invention provides a method and application for short-cut nitrification of ammonia nitrogen wastewater. It proposes for the first time the use of low concentrations of cerium to selectively enrich endogenous heterotrophic nitrifying bacteria, and to increase the accumulation rate of nitrite by synergistic action of cerium ions with autotrophic nitrifying bacteria. Furthermore, by regulating the metabolic type of endogenous organic matter, it promotes close cooperation between autotrophic and heterotrophic nitrifying bacteria, realizing the synergistic effect of autotrophic and heterotrophic nitrifying bacteria and breaking through the inherent rate limitation of autotrophic nitrifying bacteria.

[0007] To address the aforementioned problems, this invention provides a method for short-cut nitrification of ammonia nitrogen wastewater. The method includes: S100, inoculation: inoculating a reactor with mature autotrophic short-cut nitrification sludge to obtain a first mixed liquor; S200, influent: pumping water containing ammonium salts, bicarbonate, and phosphate into the reactor; S300, stirring and aeration: mixing the first mixed liquor in the reactor with the water containing ammonium salts, bicarbonate, and phosphate using a stirrer and aerating the mixture to obtain a second mixed liquor; S400, settling and separation: stopping stirring, aeration, and pH control of the second mixed liquor, and performing solid-liquid separation to obtain treated water and sludge; S500, effluent: activating an effluent pump to uniformly discharge the treated water; S600, operation: repeating steps S200-S500 for long-term operation; wherein, step S600 further includes adding cerium chloride solution and continuing operation.

[0008] Compared with existing technologies, the technical effects achieved by this technical solution are as follows: This invention proposes for the first time the use of cerium to selectively enrich endogenous heterotrophic nitrifying bacteria. Through the synergistic work of cerium ions and autotrophic nitrifying bacteria, the accumulation rate and yield of nitrite can be significantly improved. At the same time, it also solves the problems of high greenhouse gas emissions and nitrogen loss in traditional methods, achieving significant environmental benefits. By controlling the cerium concentration, the emission of greenhouse gases such as N2O is reduced. Furthermore, by regulating the metabolic type of endogenous organic matter, it promotes close cooperation between autotrophic and heterotrophic nitrifying bacteria, realizing the synergistic effect of autotrophic and heterotrophic nitrifying bacteria, breaking through the inherent rate limitation of autotrophic nitrifying bacteria. Compared with traditional nitrification and denitrification processes, this invention does not require an external organic carbon source and has lower aeration energy consumption, while still achieving high nitrification efficiency.

[0009] In one technical solution of the present invention, step S600 specifically includes: S601, repeating steps S200-S500 for 20 days; S602, adding cerium chloride solution based on step S601 and running for 20 days.

[0010] Compared with existing technologies, the technical effects achieved by this solution are as follows: By repeating steps S200 to S500 in step S601, the long-term stability of the system is verified. The repeated reaction process ensures that the ammonia nitrogen wastewater treatment system can continuously and efficiently remove ammonia nitrogen without performance degradation. Furthermore, continuous operation for 20 days can fully optimize the reaction conditions and the stability of the microbial community, ensuring that the microorganisms in the reactor can adapt to the changing factors in the wastewater, thereby maximizing the treatment effect. Long-term operation ensures that autotrophic and heterotrophic nitrifying bacteria in the reactor can fully adapt and work synergistically, thus guaranteeing the continuity and efficiency of the treatment process. Finally, through repeated operation, the effect of ammonia nitrogen removal and nitrite accumulation can be systematically monitored, thereby providing data support for further process optimization.

[0011] In step S602, the addition of cerium chloride solution further enhances the treatment effect while maintaining stable reactor operation, demonstrating strong flexibility and adaptability. Cerium ions promote the enrichment of endogenous heterotrophic nitrifying bacteria and synergistically work with autotrophic nitrifying bacteria to further increase the accumulation rate and conversion efficiency of nitrite, thereby improving the wastewater treatment rate, especially under conditions of low ammonia nitrogen concentration. In addition, the addition of cerium chloride optimizes the metabolic activities of microorganisms, especially enhancing the cooperation between autotrophic and heterotrophic bacteria, thus improving the overall nitrogen removal effect, effectively reducing the residual ammonia nitrogen, and improving the stability of treated water quality. The addition of cerium ions not only enhances the nitrification reaction but also reduces greenhouse gas emissions, which has a positive effect on environmental protection, especially in the long-term operation, reducing the greenhouse gases generated during nitrogen conversion.

[0012] In one embodiment of the present invention, the concentration of the cerium chloride solution is 0.05-2.5 mg / L.

[0013] Compared with existing technologies, the technical effects achieved by this solution are as follows: Cerium chloride, as a redox catalyst, can promote the nitrification reaction in the ammonia nitrogen conversion process by microorganisms. Under the action of cerium chloride, the nitrification rate is significantly improved, especially the nitrite formation rate, thereby improving the short-range nitrification effect of the system; Cerium has a promoting effect on autotrophic and heterotrophic nitrifying bacteria, especially in the process of microbial treatment of ammonia nitrogen. Cerium ions can enhance the metabolic activity of microorganisms by regulating the redox environment, enabling more effective conversion of ammonia nitrogen into nitrite and improving nitrogen removal efficiency; Cerium ions can promote the synergistic effect of autotrophic and heterotrophic nitrifying bacteria, enhancing nitrite accumulation, from The reduced residual concentration of ammonia nitrogen further optimizes the treatment effect. While nitrification generates greenhouse gases, setting the cerium chloride concentration within the range of 0.05-2.5 mg / L helps to reduce emissions of nitrogen oxides and other greenhouse gases while ensuring efficient removal of ammonia nitrogen, thus improving environmental friendliness. At appropriate concentrations, cerium chloride can also enhance the stability of the microbial community within the system, making the microbial community more stable and enabling it to continuously and efficiently convert ammonia nitrogen during long-term operation, thereby enhancing the long-term stability and reliability of the system. Finally, with a cerium chloride concentration of only 0.05-2.5 mg / L, this low concentration will not cause secondary pollution to the environment, while significantly improving wastewater treatment efficiency and demonstrating good environmental benefits.

[0014] In one technical solution of the present invention, in step S100: the reactor is a sequencing batch reactor; and / or the effective volume of the reactor is 4L; and / or the reactor effluent exchange ratio is 50%; and / or the volume of autotrophic short-cut nitrification sludge accounts for 3%-5% of the effective volume of the reactor; and / or the concentration of volatile suspended solids in the first mixed liquor is 1500-2200 mgVSS / L.

[0015] Compared with existing technologies, the technical effects achieved by this solution are as follows: The sequencing batch reactor (SBR) adopts a batch reaction and periodic operation approach, effectively controlling the nitrification process of ammonia nitrogen through multiple stage switching, ensuring the optimization of conditions such as oxygen supply, reaction time, and sludge settling, and promoting the smooth progress of the nitrification process; the effective volume of the reactor is 4L, which determines the reactor's processing capacity, sludge retention time, and reaction time of ammonia nitrogen wastewater. With an effective volume of 4L, sufficient reaction time can be ensured, allowing the short-cut nitrification process to proceed smoothly; the reactor's effluent exchange ratio is 50%, meaning that at the end of each cycle, 50% of the water in the reactor is discharged and exchanged with fresh water. A 50% effluent exchange ratio ensures a continuous supply of fresh water, helping to maintain reactant and sludge concentrations within suitable ranges in the reactor. Regular drainage and replenishment prevent excessive sludge accumulation, avoiding high concentrations that could inhibit microbial activity. The proportion of autotrophic short-cut nitrification sludge in the reactor's effective volume is 3%-5%, ensuring a sufficient number of nitrifying bacteria to meet the ammonia nitrogen wastewater treatment requirements. Appropriate sludge concentration also improves ammonia nitrogen conversion efficiency, ensuring smooth nitrification and preventing the impact of insufficient or excessive sludge on reaction efficiency. The volatile suspended solids (VSS) concentration in the first mixed liquor is 1500-2200 mgVSS / L. VSS represents the number and metabolic activity of active microorganisms in the reactor. A moderate VSS concentration helps ensure sufficient microbial biomass for short-cut nitrification, especially the activity of autotrophic and heterotrophic nitrifying bacteria. It also enhances the adaptability and stability of microorganisms, reducing reaction efficiency reduction due to sludge aging.

[0016] In one technical solution of the present invention, in step S100: the abundance of nitrifying mononuclear bacteria in the mature autotrophic short-cut nitrification sludge is greater than 40%; and / or the mature autotrophic short-cut nitrification sludge includes at least one of extracellular polymers, denitrifying bacteria, and anaerobic bacteria.

[0017] Compared with existing technologies, the technical effects achieved by this solution are as follows: *Nitrosomonas* is a key microorganism in short-cut nitrification, oxidizing ammonia nitrogen to nitrite. In mature autotrophic short-cut nitrification sludge, the abundance of *Nitrosomonas* is greater than 40%, indicating that nitrifying microorganisms dominate the system. High abundance of *Nitrosomonas* significantly increases the conversion rate of ammonia nitrogen to nitrite, thereby enhancing short-cut nitrification efficiency. Furthermore, it effectively competes for and inhibits the second step of nitrification, leading to nitrite accumulation, which is beneficial for short-cut nitrification and subsequent denitrification. Finally, nitrifying bacteria can maintain a high ammonia nitrogen removal capacity under conditions of load fluctuations and oxygen concentration changes, enhancing the system's operational stability. Extracellular polymeric substances (EPS) are also present. Substances (EPS) are polysaccharides, proteins, and other substances secreted by microorganisms during metabolism. These substances protect and support the microbial community in sludge. EPS increases the cohesion of sludge particles, improves sludge settling performance, ensures good solid-liquid separation in the reactor, and provides a protective barrier for microorganisms, improving their tolerance to changes in the external environment and enhancing the system's shock resistance. Finally, EPS helps stabilize the microbial community structure, promoting the long-term survival and activity of Nitrifying Monotrophs and other microorganisms in the reactor. Denitrifying bacteria can reduce nitrite or nitrate to nitrogen gas and are an important microbial community in short-cut nitrification-denitrification systems. Denitrifying bacteria can thrive in anaerobic environments. Under certain conditions, nitrite is directly converted into nitrogen gas, thereby reducing nitrogen pollution and improving the total nitrogen removal rate. During short-cut nitrification, the accumulation of nitrite may lead to secondary pollution, while denitrifying bacteria can consume these intermediate products in a timely manner, reducing the accumulation of nitrate and nitrite. Anaerobic bacteria are mainly responsible for the degradation of organic matter or assisting in the ammonia nitrogen conversion process in the reactor. Anaerobic bacteria can degrade organic matter in wastewater, reducing the interference of carbon-nitrogen imbalance on short-cut nitrification. Anaerobic bacteria form a diverse microbial ecosystem with other bacterial species, which helps maintain the microecological balance in the reactor and improves the system's resistance to fluctuations. Anaerobic bacteria can work synergistically with denitrifying bacteria to improve the reduction and utilization of nitrite, further reducing nitrogen pollution.

[0018] In one embodiment of the present invention, in step S200: the concentration range of ammonium salt is between 0-200 mgN / L; and / or the concentration range of bicarbonate is between 0-200 mgN / L; and / or the concentration range of phosphate is between 0-1.74 mgP / L.

[0019] Compared with existing technologies, the technical effects achieved by this solution are as follows: Ammonium salts are the main nitrogen source in ammonia nitrogen wastewater treatment, participating in the nitrification and short-cut nitrification processes. With ammonium salt concentrations ranging from 0-200 mgN / L, the concentration of ammonia nitrogen in the wastewater can be adjusted to optimize the ammonia nitrogen conversion efficiency during nitrification. This helps maintain a suitable ammonia nitrogen concentration in the reactor, avoiding the inhibitory effects of excessively high ammonia nitrogen concentrations on the nitrification process and microorganisms. Within the 0-200 mgN / L concentration range, the moderate ammonium salt concentration is beneficial to the growth and metabolism of nitrifying bacteria, thereby improving the ammonia nitrogen conversion rate and short-cut nitrification effect. Furthermore, it helps improve system stability, avoiding ammonia nitrogen toxicity due to excessively high concentrations or nitrification process stagnation due to excessively low concentrations. Bicarbonate, as a buffer in the water, helps maintain the pH level in the reactor. A stable pH value is crucial to prevent excessively low pH levels caused by acidic byproducts during nitrification, which can negatively impact microbial activity. An appropriate concentration of bicarbonate effectively buffers the acids produced during the reaction, maintaining the pH within a suitable range. This promotes the activity of nitrifying microorganisms and ammonia nitrogen conversion, helping to maintain pH stability within the reactor and preventing reduced nitrite or ammonia nitrogen removal efficiency in acidic environments. Phosphate is an essential nutrient for microbial growth, especially in autotrophic nitrification, where phosphorus is a key substance for cell synthesis and energy conversion. Appropriate phosphate concentrations promote the growth and activity of Nitrosomonas and other nitrifying microorganisms, helping to maintain microbial reproduction and metabolic activities, and improving ammonia nitrogen conversion efficiency. Conversely, excessively low phosphate concentrations limit nitrifying bacteria growth and affect ammonia nitrogen removal efficiency.

[0020] In one technical solution of the present invention, in step S200: the carbon-nitrogen ratio in the water containing ammonium salt, bicarbonate and phosphate is 0.8 and the phosphorus-nitrogen ratio is 0.005; wherein, the carbon source is carbonate or bicarbonate.

[0021] Compared with existing technologies, the technical effects achieved by this solution are as follows: The carbon-to-nitrogen ratio (C / N ratio) is one of the important parameters affecting microbial metabolism in water treatment, especially in the biotransformation of ammonia nitrogen. Setting the C / N ratio to 0.8 helps to inhibit denitrification, ensuring that ammonia nitrogen is mainly removed through nitrification. Furthermore, since denitrification requires a carbon source as an electron donor, a C / N ratio within this range avoids excessive carbon source promoting denitrification, ensuring that the system mainly performs short-cut nitrification. This allows microorganisms to carry out nitrification at the optimal rate, improving the efficiency of ammonia nitrogen conversion to nitrite, thereby improving the system's treatment effect. The phosphorus-to-nitrogen ratio is the ratio of phosphorus to nitrogen sources in the reaction system. A phosphorus-to-nitrogen ratio of 0.005 indicates that the phosphorus concentration in the water is much lower than the nitrogen concentration. This means that the phosphorus source plays an auxiliary role in the system, mainly supporting the growth of microorganisms and preventing insufficient phosphorus from affecting the nitrification process. An excessively high phosphorus-to-nitrogen ratio leads to the accumulation of excessive phosphorus, which in turn leads to eutrophication of the water body. Carbonates and bicarbonates, as carbon sources, can provide a buffering effect and provide the carbon source required by microorganisms. While maintaining the stability of the pH value in the reactor, they can also support the energy metabolism of microorganisms during short-cut nitrification. As buffers and carbon sources, carbonates and bicarbonates can enhance the stability of the system and reduce the fluctuations in microbial activity caused by pH fluctuations, thereby ensuring the long-term efficient operation of the short-cut nitrification process.

[0022] In one technical solution of the present invention, in step S300: the aeration reaction is performed by aeration for 30 minutes every 30 minutes; and / or the dissolved oxygen concentration is 0.1 mg / L during the aeration reaction; and / or the dissolved oxygen concentration is less than 0.1 mg / L at the end of the aeration reaction.

[0023] Compared with existing technologies, the technical effects achieved by this solution are as follows: In step S300, the intermittent aeration mode helps simulate natural oxygen supply conditions, avoiding excessive accumulation and depletion of dissolved oxygen in the reactor, making oxygen supply and consumption more balanced, thereby promoting the aerobic reaction in the short-cut nitrification process. Simultaneously, it avoids unnecessary energy consumption caused by excessive oxygen supply and ensures that dissolved oxygen is kept at a low level to meet the needs of autotrophic short-cut nitrification microorganisms, preventing excessive microbial growth or competition due to continuous aeration, thus maintaining the ecological balance within the reactor. At low dissolved oxygen concentrations, the system is beneficial for… The growth and activity of nitrifying bacteria are crucial. These bacteria can convert ammonia nitrogen into nitrite, thereby removing ammonia nitrogen. In addition, they can reduce denitrification, prevent nitrogen oxides from being converted into nitrogen gas and wasting nitrogen source, thus reducing oxygen consumption and improving the energy efficiency of the system. At the end of aeration, the oxygen concentration drops to a very low level, which is conducive to strengthening the dominant position of nitrifying bacteria during oxygen consumption, while reducing excessive promotion of other microorganisms. This enhances the short-cut nitrification reaction in the autotrophic short-cut nitrification process, which helps to generate nitrite rather than further converting it into nitrate.

[0024] In one embodiment of the present invention, in step S300, the pH value of the second mixture is between 8.8 and 9.

[0025] Compared with existing technologies, the technical effects achieved by this solution are as follows: Controlling the pH of the second mixed liquor within the range of 8.8-9 allows nitrifying bacteria to be more active in a slightly alkaline environment, effectively oxidizing ammonia nitrogen to nitrite and maintaining optimal conditions for the reaction of ammonia nitrogen with oxygen, thus accelerating the conversion process and improving wastewater treatment efficiency. On the one hand, pH plays a crucial regulatory role in the growth and metabolism of microorganisms. Within this range, autotrophic short-range nitrifying bacteria can adapt and grow better, improving their performance in the ammonia nitrogen conversion process. When the pH is too low, some microorganisms may be inhibited or die. On the other hand, maintaining the pH within the range of 8.8-9 can effectively inhibit the activity of denitrifying bacteria, preventing nitrate from being reduced to nitrogen gas, thereby increasing the conversion ratio of ammonia nitrogen to nitrite. Finally, excessively low or high pH values ​​may cause fluctuations in microbial activity in the reactor, affecting the treatment effect. Within this pH range, stable microbial metabolism is ensured, improving the stability of the entire system.

[0026] This invention provides an application of short-cut nitrification for ammonia nitrogen wastewater, employing any of the methods described above. Therefore, it includes the beneficial effects of any of the above technical solutions, which will not be elaborated upon here.

[0027] By adopting the technical solution of the present invention, the following technical effects can be achieved:

[0028] (1) Low greenhouse gas production: After treatment with low concentrations of cerium, nitrogen loss and greenhouse gas emissions were reduced by 83%;

[0029] (2) Strong processing capacity: The rate of nitrite accumulation and the processing capacity increased by 33% during the long-term operation phase;

[0030] (3) Easy to control: The key operating parameters such as pH value, dissolved oxygen concentration and cerium ion required for long-term operation have fixed parameters. Attached Figure Description

[0031] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings to be used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a graph showing the changes in nitrogen concentration during long-term operation before and after low-dose cerium treatment in Example 1 of this invention;

[0033] Figure 2 This is a graph showing the changes in total nitrogen during long-term operation before and after low-dose cerium treatment in Example 1 of this invention;

[0034] Figure 3 This is a graph showing the nitrogen conversion rate before and after low-dose cerium treatment provided in the batch test of Embodiment 1 of the present invention;

[0035] Figure 4 This is a diagram showing the microbial community structure before and after low-dose cerium treatment in Example 1 of this invention;

[0036] Figure 5 This is a diagram showing the expression evolution of nitrogen-converting enzyme-related pathways in Example 1 of the present invention. Detailed Implementation

[0037] To make the above-mentioned objectives, features, and advantages of the present invention more apparent and understandable, the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] This invention provides a method for short-cut nitrification of ammonia nitrogen wastewater. By continuously operating an inoculated mature sludge reactor for 20 days, a short-cut nitrification reactor exhibiting nitrogen loss after long-term operation is simulated. Through long-term treatment with low-dose cerium, many anaerobic fermentation and denitrifying bacteria that are not adapted to cerium rapidly die off. Under conditions of 0-1.0 mg / L concentration, pH 8.9±0.3, and dissolved oxygen 0.1 mg / L, cerium rapidly accumulates in heterotrophic nitrification-denitrification and anaerobic fermentation bacteria, making them the dominant bacteria second only to nitrosomonas. Anaerobic fermentation bacteria utilize EPS decomposition to produce suitable small-molecule organic matter. Heterotrophic nitrification-denitrification utilizes these endogenous organic carbon sources to convert ammonia nitrogen into nitrate, and then reduces nitrate to nitrite, achieving rapid autotrophic-endogenous heterotrophic short-cut nitrification. Nor enzyme is a key enzyme in the conversion of nitrite to N2O; low-dose cerium leads to a significant downregulation of Nor enzyme expression, thereby reducing N2O production and achieving endogenous short-cut denitrification.

[0039] Example 1

[0040] This embodiment provides a method and application for short-cut nitrification of ammonia nitrogen wastewater. The specific operation steps are as follows:

[0041] S100, Inoculation: Mature autotrophic short-cut nitrification sludge is inoculated into a sequencing batch reactor with an effective volume of 4L and an effluent exchange ratio of 50% to obtain the first mixed liquor.

[0042] Among them, the mature autotrophic short-cut nitrification sludge was formed by culturing ZL202210842055.1 and the short-cut nitrification reactor had been running for 6 months. The volume of the autotrophic short-cut nitrification sludge accounted for 3% of the effective volume of the reactor. The concentration of volatile suspended solids in the first mixed liquor was 1500 mg VSS / L. The abundance of nitrifying mononuclear bacteria in the mature autotrophic short-cut nitrification sludge was greater than 40%. The mature autotrophic short-cut nitrification sludge included extracellular polymers, denitrifying bacteria, and anaerobic bacteria.

[0043] S200, Influent: Water with concentrations of 150 mg N / L, 150 mg C / L and 0.87 mg P / L of ammonium salt, bicarbonate and phosphate is pumped into the reactor. The influent carbon-nitrogen ratio is 0.8 and the phosphorus-nitrogen ratio is 0.005. Carbonate is used as the carbon source.

[0044] S300, Stirring and Aeration: The first mixture in the reactor is mixed with water containing ammonium salt, bicarbonate and phosphate by a stirrer, and aeration is carried out for 30 minutes every 30 minutes. The dissolved oxygen concentration during aeration is 0.1 mg / L, resulting in the second mixture, with the pH value maintained at 8.8.

[0045] S400, settling and separation: At a temperature range of 12-20℃, stop stirring, aeration and pH control of the second mixture, and carry out solid-liquid separation within 10 minutes to obtain treated water and sludge. The dissolved oxygen concentration is less than 0.1mg / L at the end of the aeration reaction.

[0046] S500, Water Discharge: Activate the water discharge pump to evenly discharge the treated water;

[0047] S600, Operation: Repeat steps S200-S500 for 20 days of long-term operation, add 0.5 mg / L cerium chloride solution, and continue to operate for 20 days.

[0048] Example 2

[0049] This embodiment provides a method and application for short-cut nitrification of ammonia nitrogen wastewater. The specific operation steps are as follows:

[0050] S100, Inoculation: Mature autotrophic short-cut nitrification sludge is inoculated into a sequencing batch reactor with an effective volume of 4L and an effluent exchange ratio of 50% to obtain the first mixed liquor.

[0051] Among them, the mature autotrophic short-cut nitrification sludge was formed by culturing ZL202210842055.1, and the short-cut nitrification reactor had been running for 6 months. The volume of the autotrophic short-cut nitrification sludge accounted for 5% of the effective volume of the reactor. The concentration of volatile suspended solids in the first mixed liquor was 2200 mg VSS / L. The abundance of nitrosomonas in the mature autotrophic short-cut nitrification sludge was greater than 40%. The mature autotrophic short-cut nitrification sludge included extracellular polymers, denitrifying bacteria, and anaerobic bacteria.

[0052] S200, Influent: Water with concentrations of 200 mg N / L, 200 mg C / L and 1.74 mg P / L of ammonium salt, bicarbonate and phosphate is pumped into the reactor. The influent carbon-nitrogen ratio is 0.8 and the phosphorus-nitrogen ratio is 0.005. Carbonate is used as the carbon source.

[0053] S300, Stirring and Aeration: The first mixture in the reactor is mixed with water containing ammonium salt, bicarbonate and phosphate by a stirrer, and aeration is carried out for 30 minutes every 30 minutes. The dissolved oxygen concentration during aeration is 0.1 mg / L, and the second mixture is obtained, with the pH value maintained at 9.

[0054] S400, settling and separation: At a temperature range of 12-20℃, stop stirring, aeration and pH control of the second mixture, and carry out solid-liquid separation within 10 minutes to obtain treated water and sludge. The dissolved oxygen concentration is less than 0.1mg / L at the end of the aeration reaction.

[0055] S500, Water Discharge: Activate the water discharge pump to evenly discharge the treated water;

[0056] S600, Operation: Repeat steps S200-S500 for 20 days of long-term operation, add 2.5 mg / L cerium chloride solution, and continue to operate for 20 days.

[0057] Example 3

[0058] This embodiment provides a method and application for short-cut nitrification of ammonia nitrogen wastewater. The specific operation steps are as follows:

[0059] S100, Inoculation: Mature autotrophic short-cut nitrification sludge is inoculated into a sequencing batch reactor with an effective volume of 4L and an effluent exchange ratio of 50% to obtain the first mixed liquor.

[0060] Among them, the mature autotrophic short-cut nitrification sludge was formed by culturing ZL202210842055.1 and the short-cut nitrification reactor had been running for 6 months. The volume of the autotrophic short-cut nitrification sludge accounted for 4% of the effective volume of the reactor. The concentration of volatile suspended solids in the first mixed liquor was 2000 mg VSS / L. The abundance of nitrosomonas in the mature autotrophic short-cut nitrification sludge was greater than 40%. The mature autotrophic short-cut nitrification sludge included extracellular polymers, denitrifying bacteria, and anaerobic bacteria.

[0061] S200, Influent: Water with concentrations of 15 mg N / L, 15 mg C / L and 0.05 mg P / L of ammonium salt, bicarbonate and phosphate is pumped into the reactor. The influent carbon-nitrogen ratio is 0.8 and the phosphorus-nitrogen ratio is 0.005. Carbonate is used as the carbon source.

[0062] S300, Stirring and Aeration: The first mixture in the reactor is mixed with water containing ammonium salt, bicarbonate and phosphate by a stirrer, and aeration is carried out for 30 minutes every 30 minutes. The dissolved oxygen concentration during aeration is 0.1 mg / L, and the second mixture is obtained, with the pH value maintained at 9.

[0063] S400, settling and separation: At a temperature range of 12-20℃, stop stirring, aeration and pH control of the second mixture, and carry out solid-liquid separation within 10 minutes to obtain treated water and sludge. The dissolved oxygen concentration is less than 0.1mg / L at the end of the aeration reaction.

[0064] S500, Water Discharge: Activate the water discharge pump to evenly discharge the treated water;

[0065] S600, Operation: Repeat steps S200-S500 for 20 days of long-term operation, add 0.05 mg / L cerium chloride solution, and continue to operate for 20 days.

[0066] Analysis of measured indicators:

[0067] The influent and effluent samples were measured after being filtered through qualitative analysis filter paper. NH 4+ -N、NO 2− -N and NO 3− The concentration tests for -N were all conducted in accordance with the standard methods of "Methods for Testing and Analysis of Water and Wastewater" (Fourth Edition) compiled by the State Environmental Protection Administration of China.

[0068] NH 4+ The quantitative detection of -N was performed using Nessler's reagent spectrophotometry.

[0069] NO 2− The quantitative detection of -N was performed using the N-(1-naphthyl)-ethylenediamine spectrophotometric method;

[0070] NO 3− -N quantitative detection was performed using the aminosulfonic acid ultraviolet spectrophotometric method.

[0071] Sludge samples from Example 1 were obtained from the reactor on days 20 and 42, and high-throughput sequencing, microbial community analysis, and metabolic pathway analysis were performed.

[0072] like Figure 1 As shown, after long-term operation from day 1 to day 20, the effluent nitrite nitrogen concentration began to be significantly lower than the influent ammonia nitrogen concentration, while the effluent ammonia nitrogen and nitrate nitrogen concentrations remained at low levels, indicating that significant nitrogen loss occurred after long-term operation of short-cut nitrification. From day 21 to day 42, after the addition of 0.5 mg / L cerium to the influent, the effluent nitrite nitrogen concentration gradually approached the influent ammonia nitrogen concentration, while the effluent ammonia nitrogen and nitrate nitrogen concentrations remained at low levels, indicating that nitrogen loss was significantly reduced after long-term operation of short-cut nitrification, and the proportion of ammonia nitrogen converted to nitrite nitrogen significantly increased from 83.01±1.08% to 94.22±1.14%.

[0073] like Figure 2 As shown, after long-term operation from day 1 to day 20, the total nitrogen in the effluent was lower than that in the influent, confirming the occurrence of a large amount of nitrogen loss; from day 21 to day 42, after adding 0.5 mg / L of cerium to the influent, the nitrogen loss gradually decreased from 23.74±4.61 mg / L to 4.01±2.42 mg / L, a reduction of 83.11%.

[0074] like Figure 3 As shown, the nitrite production rate on day 20 (R1) and day 42 (R2) was determined by sampling every hour. Compared with the nitrite production rate of R1 (6.66±0.87 mgN / L / h), the nitrite production rate of R2 (8.89±2.85 mgN / L / h) increased by 33.48%.

[0075] like Figure 4As shown, norank_A4b is an anaerobic fermenting bacterium that can decompose large EPS molecules in sludge into easily usable small organic molecules; Pseudofulvimonas is classified as heterotrophic nitrification-aerobic denitrification and has been reported to utilize small organic molecules for endogenous heterotrophic short-cut nitrification to produce nitrite; as a functional bacterium for short-cut nitrification, the relative abundance of Nitrosomonas decreased from 43.53% to 16.85%, while the amount and rate of nitrite production increased significantly, indicating that endogenous short-cut denitrification became an important pathway for nitrite supply after treatment with 0.5 mg / L cerium.

[0076] like Figure 5 As shown, the expression of functional enzymes in autotrophic short-cut nitrification (Amo and Hao) was significantly downregulated by 51.09% and 50.36%, respectively, while the expression of functional enzyme in endogenous heterotrophic short-cut nitrification (Nad2) was significantly upregulated by 77.17%, and the expression of functional enzymes producing N2O (NirBC and Nor) was significantly downregulated by 32.21% and 38.98%, respectively.

[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for short-cut nitrification of ammonia nitrogen wastewater, characterized in that, The method comprises: S100, inoculation: inoculating mature autotrophic partial nitrification sludge into a reactor to obtain a first mixed liquor; S200, water feeding: feeding water containing ammonium salt, bicarbonate and phosphate into the reactor through a water feeding pump; S300, stirring and aeration: mixing the first mixed liquor in the reactor with the water containing ammonium salt, bicarbonate and phosphate through a stirrer and performing an aeration reaction to obtain a second mixed liquor; S400, standing and separation: stopping stirring, aeration and pH control of the second mixed liquor and performing solid-liquid separation to obtain treated water and sludge; S500, water discharge: enabling a water discharge pump to uniformly discharge the treated water; S600, operation: repeating steps S200-S500 to perform long-term operation; In step S600, cerium chloride solution is further added and the operation is continuously performed, and the concentration of the cerium chloride solution is 0.05-2.5 mg / L.

2. The method for short-cut nitrification of ammonia nitrogen wastewater according to claim 1, characterized in that, The step S600 specifically comprises: S601, repeating steps S200-S500 for 20 days; S602, on the basis of step S601, adding the cerium chloride solution and performing operation for 20 days.

3. The method for ammonia nitrogen wastewater short-cut nitrification according to claim 1, characterized in that, In step S100: The reactor is a sequencing batch reactor; and / or The effective volume of the reactor is 4 L; and / or The water exchange ratio of the reactor is 50%; and / or The volume ratio of the autotrophic partial nitrification sludge in the reactor effective volume is 3%-5%; and / or The volatile suspended solid concentration in the first mixed liquor is 1500-2200 mgVSS / L.

4. The method for ammonia nitrogen wastewater short-cut nitrification according to claim 1, characterized in that, In step S100: The abundance of Nitrosomonas in the mature autotrophic partial nitrification sludge is greater than 40%; and / or The mature autotrophic partial nitrification sludge comprises at least one of extracellular polymeric substance, denitrifying bacteria and anaerobic bacteria.

5. The method for ammonia nitrogen wastewater short-cut nitrification according to claim 1, characterized in that, In step S200: The concentration of the ammonium salt ranges between 0-200 mgN / L; and / or The concentration of the bicarbonate ranges between 0-200 mgN / L; and / or The concentration of the phosphate ranges between 0-1.74 mgP / L.

6. The method for short-cut nitrification of ammonia nitrogen wastewater according to claim 1, characterized in that, In step S200, the carbon-nitrogen ratio of the water containing ammonium salt, bicarbonate and phosphate is 0.8, and the phosphorus-nitrogen ratio is 0.

005.

7. The method for ammonia nitrogen wastewater short-cut nitrification according to claim 1, characterized in that, In step S300: The aeration reaction is 30 min of aeration every 30 min; and / or The dissolved oxygen concentration during the aeration reaction is 0.1 mg / L; and / or The dissolved oxygen concentration at the end of the aeration reaction is lower than 0.1 mg / L.

8. The method for short-cut nitrification of ammonia nitrogen wastewater according to claim 1, characterized in that, In step S300, the pH value of the second mixed liquor ranges between 8.8-9.

9. The use of ammonia-nitrogen wastewater short-cut nitrification, characterized in that, The method according to any one of claims 1-8 is used to treat ammonia-nitrogen wastewater.

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