Nitrogen and phosphorus removal sewage treatment method and system

Abstract

The invention provides a nitrogen and phosphorus removal sewage treatment method and system.The method comprises the steps that sewage is pretreated by arranging a grating and a grit chamber, so that large-particle matter and suspended matter in the sewage are removed; introducing the pretreated sewage into a mixed reaction zone provided with a biofilm carrier for removing nitrogen and phosphorus in the sewage; carrying out precipitation separation on the sewage treated by the mixed reaction zone, and enabling part of sludge separated by precipitation to flow back to the mixed reaction zone so as to realize cyclic utilization of the sludge; and filtering and disinfecting the filtered water after the precipitation separation, so that the effluent reaches the sewage treatment standard. According to the method, a biofilm process and an activated sludge process are combined, and a novel adsorption material and specific microorganisms are utilized, so that efficient nitrogen and phosphorus removal under a low-energy-consumption condition is realized, the operation cost and the energy consumption are remarkably reduced, meanwhile, the use of chemicals is avoided, and secondary pollution is reduced.

Description

Technical Field

[0001] The present disclosure relates to the technical field of water treatment, and in particular to a sewage treatment method and system for nitrogen and phosphorus removal. Background Art

[0002] In the field of wastewater treatment, traditional nitrogen and phosphorus removal technologies often face problems such as high energy consumption, high operating costs and unstable treatment effects. These problems are mainly due to the fact that traditional processes rely on high-energy aeration processes and the use of chemicals, and are also affected by fluctuations in influent water quality and changes in environmental conditions.

[0003] For example, the traditional nitrification and denitrification process requires a lot of aeration to provide enough dissolved oxygen to support the growth and activity of aerobic microorganisms, and this process consumes a lot of energy. In addition, chemical phosphorus removal methods require the addition of chemicals, such as aluminum salts or iron salts, which not only increase the cost of treatment, but may also produce sludge containing heavy metals, causing secondary pollution to the environment. Furthermore, sewage treatment plants often need to deal with fluctuations in influent water quality, such as sudden increases in nitrogen and phosphorus concentrations, as well as changes in temperature and pH values. These factors may affect the activity and treatment efficiency of microorganisms, resulting in unstable effluent quality. Summary of the invention

[0004] In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a sewage treatment method and system for nitrogen and phosphorus removal, which aims to improve the sewage treatment efficiency by combining the biofilm method with the activated sludge method.

[0005] The first aspect of the present disclosure provides a wastewater treatment method for nitrogen and phosphorus removal, comprising:

[0006] Pre-treat the sewage by installing screens and grit chambers to remove large particles and suspended solids in the sewage;

[0007] The pretreated sewage is introduced into a mixed reaction zone provided with a biofilm carrier to remove nitrogen and phosphorus from the sewage;

[0008] The sewage treated in the mixed reaction zone is precipitated and separated, and the sludge separated by precipitation is partially returned to the mixed reaction zone to realize the recycling of sludge;

[0009] The water filtered out after sedimentation separation is filtered and disinfected to ensure that the effluent meets sewage treatment standards.

[0010] In an embodiment of the first aspect, the biofilm carrier in the mixed reaction zone comprises:

[0011] Adsorbent materials for removing nitrogen and phosphorus compounds from wastewater by physical or chemical adsorption;

[0012] Specific microorganisms are attached to the biofilm carrier and form a biofilm, which is used to degrade nitrogen and phosphorus compounds in sewage through biological metabolic processes.

[0013] In an embodiment of the first aspect, the adsorption material comprises: modified zeolite, activated carbon and nanomaterial; wherein,

[0014] The modified zeolite uses a cation exchange mechanism to absorb nitrate ions in sewage using positively charged groups on its surface;

[0015] The activated carbon adsorbs nitrates and phosphates in sewage through a high specific surface area;

[0016] The nanomaterial forms chemical bonds with phosphates in sewage through a chemical adsorption mechanism to remove phosphorus from the sewage.

[0017] In an embodiment of the first aspect, the biofilm carrier comprises: nitrifying bacteria, denitrifying bacteria and polyphosphate bacteria; wherein,

[0018] The nitrifying bacteria are used to oxidize ammonia nitrogen in sewage into nitrite and nitrate;

[0019] The denitrifying bacteria are used to reduce nitrate in sewage to nitrogen gas under anoxic or anaerobic conditions;

[0020] The polyphosphate bacteria are used to absorb dissolved phosphorus in sewage under aerobic conditions and convert it into polyphosphate; and decompose the generated polyphosphate under anaerobic conditions and release it into the surrounding environment.

[0021] In an embodiment of the first aspect, the ratio of the nitrifying bacteria to the polyphosphate bacteria is equal to the molar ratio of nitrogen to phosphorus in the sewage; and the ratio of the nitrifying bacteria to the denitrifying bacteria is equal to ensure that the nitrate produced by nitrification can be reduced to nitrogen gas.

[0022] In an embodiment of the first aspect, the sewage treated in the mixed reaction zone is subjected to sedimentation separation, and part of the sludge separated by sedimentation is returned to the mixed reaction zone to achieve the recycling of the sludge, including:

[0023] During the sedimentation separation process, 80% (by volume) of the sludge separated by sedimentation is returned to the mixing reaction zone to promote the continuous activity of the biofilm carrier;

[0024] Discharge 10% to 30% (by volume) of the upper sewage after sedimentation separation to remove excess solids and aged biofilm carriers accumulated during the treatment process.

[0025] In an embodiment of the first aspect, filtering and disinfecting the water filtered out after the precipitation separation comprises:

[0026] Use ultrafiltration or nanofiltration technology to further remove tiny suspended particles and dissolved pollutants from water;

[0027] Degradation of organic matter in water through an oxidation process using one or a combination of ozone, hydrogen peroxide or ultraviolet light.

[0028] The second aspect of the present disclosure discloses a sewage treatment system for nitrogen and phosphorus removal, comprising:

[0029] Pre-treatment area, used to remove large particles and suspended solids from sewage by setting screens and grit chambers;

[0030] A mixing reaction zone, connected to the pretreatment zone, provided with a biofilm carrier for removing nitrogen and phosphorus from the pretreated sewage;

[0031] A sedimentation zone, connected to the mixed reaction zone, for sedimentation and separation of the sewage treated in the mixed reaction zone;

[0032] The post-treatment zone is connected to the sedimentation zone and is used to filter and disinfect the water filtered out after the sedimentation separation.

[0033] In an embodiment of the second aspect, further comprising:

[0034] The monitoring module is arranged in the post-processing area and is used for real-time monitoring of the nitrogen and phosphorus content of the water in the post-processing area.

[0035] In an embodiment of the second aspect, the post-processing zone comprises:

[0036] Advanced oxidation units, which integrate ozone generators and catalysts to degrade organic matter in water;

[0037] Membrane bioreactor unit for solid-liquid separation to improve effluent clarity.

[0038] As described above, the wastewater treatment method and system for nitrogen and phosphorus removal disclosed in the present invention have at least the following technical effects:

[0039] (1) This method combines the biofilm method with the activated sludge method and utilizes new adsorption materials and specific microorganisms to achieve efficient nitrogen and phosphorus removal under low energy consumption conditions, significantly reducing operating costs and energy consumption, while avoiding the use of chemicals and reducing secondary pollution.

[0040] (2) By optimizing the structure and proportion of the microbial flora and utilizing the physicochemical properties of the adsorption material, this method improves the system's ability to adapt to fluctuations in influent water quality, ensures the stability of the treatment effect, and at the same time promotes the recycling of sludge and reduces sludge production.

[0041] (3) Through filtration and disinfection treatment in the post-treatment area, including ultrafiltration, nanofiltration and advanced oxidation processes, the water after sedimentation and separation is further purified, ensuring that the effluent quality meets or exceeds the sewage treatment standards and is suitable for safe discharge or reuse, thereby improving the sustainability and environmental friendliness of the overall sewage treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 A schematic flow chart showing a wastewater treatment method for nitrogen and phosphorus removal according to an embodiment of the present disclosure.

[0043] Figure 2 A schematic diagram showing a biofilm carrier in one embodiment of the present disclosure.

[0044] Figure 3 A schematic diagram showing the architecture of a sewage treatment system for nitrogen and phosphorus removal according to an embodiment of the present disclosure.

[0045] Figure 4 A schematic diagram showing the operation of a sewage treatment system for nitrogen and phosphorus removal according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0046] The following is an explanation of the embodiments of the present disclosure by specific examples, and those skilled in the art can easily understand other advantages and effects of the present disclosure from the information disclosed by the present disclosure. The present disclosure can also be implemented or applied through other different specific embodiments, and the details in the present disclosure can also be modified or changed in various ways according to different viewpoints and application modules without departing from the spirit of the present disclosure. It should be noted that the embodiments in the present disclosure and the features in the embodiments can be combined with each other without conflict.

[0047] The following is a detailed description of the embodiments of the present disclosure with reference to the accompanying drawings so that those skilled in the art can easily implement the present disclosure. The present disclosure can be embodied in many different forms and is not limited to the embodiments described herein.

[0048] In the representations of the present disclosure, the reference terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" and the like mean that the specific features, structures, materials or characteristics represented in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure. Moreover, the specific features, structures, materials or characteristics represented may be combined in any one or a group of embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples represented in the present disclosure and the features of different embodiments or examples, unless they are mutually contradictory.

[0049] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the representation of the present disclosure, "a group" means two or more, unless otherwise clearly and specifically defined.

[0050] In order to clearly describe the present disclosure, components not related to the description are omitted, and the same reference numerals are given to the same or similar components throughout the specification.

[0051] Throughout the specification, when a device is said to be "connected" to another device, this includes not only the case of "direct connection" but also the case of "indirect connection" by placing other elements therebetween. In addition, when a device is said to "include" a certain component, unless otherwise stated, it does not exclude other components, but means that other components may be included.

[0052] The technical terms used herein are only used to refer to specific embodiments and are not intended to limit the present disclosure. The singular form used herein also includes the plural form unless the sentence clearly indicates the contrary meaning. The meaning of "including" used in the specification is to specify specific characteristics, regions, integers, steps, operations, elements and / or components, and does not exclude the existence or addition of other characteristics, regions, integers, steps, operations, elements and / or components.

[0053] Although not defined differently, all terms, including technical and scientific terms used herein, have the same meaning as those generally understood by those skilled in the art to which the present disclosure belongs. Terms defined in commonly used dictionaries are additionally interpreted as having meanings consistent with relevant technical literature and the message of the present disclosure, and shall not be overly interpreted as ideal or very formal meanings unless defined.

[0054] Traditional wastewater treatment technologies have problems such as high energy consumption, high costs, and unstable effects in nitrogen and phosphorus removal. These challenges mainly stem from the reliance on large amounts of aeration in the nitrification and denitrification processes, as well as the increased costs and potential secondary pollution brought about by chemical phosphorus removal methods. In addition, fluctuations in influent water quality, such as changes in nitrogen and phosphorus concentrations and fluctuations in temperature and pH, can also affect the activity of microorganisms, leading to reduced treatment efficiency.

[0055] To meet these challenges, wastewater treatment technology is developing towards a more efficient, economical and environmentally friendly direction. Among them, the combination of biofilm method and activated sludge method, as well as the application of new adsorption materials and specific microorganisms, show significant potential. The biofilm method improves the contact efficiency between microorganisms and pollutants by fixing microorganisms on carriers, while the activated sludge method uses suspended microorganisms to degrade organic matter. The combination of the two can enhance the system's ability to resist shock loads and adaptability.

[0056] The technical solutions in the embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0057] like Figure 1 As shown, a schematic flow chart of a wastewater treatment method for nitrogen and phosphorus removal disclosed in the present invention is shown, including steps S11-S14.

[0058] Step S11: pre-treating the sewage by setting a screen and a grit chamber to remove large particles and suspended matter in the sewage.

[0059] Specifically, in the primary stage of sewage treatment, pretreatment is mainly achieved by setting up screens and grit chambers. As the first line of defense in pretreatment, screens are used to intercept and remove large floating objects and suspended solids in sewage, such as branches, plastic bags, bottles and other large particles that may interfere with subsequent treatment equipment. Screens are usually composed of a set of parallel metal bars or mesh structures. Depending on the size of the particles in the sewage, the gaps between the screens will vary to ensure effective interception.

[0060] The wastewater then flows into a grit chamber, a step designed to remove sand, gravel and other heavy particulate matter from the wastewater. Grit chambers work by gravity, where the wastewater velocity slows down, allowing heavy particulate matter to settle to the bottom of the chamber. This sediment is then removed regularly to prevent it from being resuspended in subsequent treatment processes.

[0061] Through pretreatment of screens and grit chambers, not only can the subsequent treatment equipment be protected from damage and the operating efficiency and service life of the entire sewage treatment system be improved, but also the sludge treatment volume can be reduced and the load of the subsequent treatment stage can be reduced, laying a solid foundation for achieving more efficient biological treatment and better effluent water quality.

[0062] Step S12: introducing the pretreated sewage into a mixed reaction zone provided with a biofilm carrier to remove nitrogen and phosphorus from the sewage.

[0063] In some embodiments, the mixed reaction zone is equipped with a biofilm carrier, such as Figure 2 As shown, this is a special medium whose surface allows specific microorganisms to attach and form biofilms.

[0064] Exemplarily, specific microorganisms include nitrifying bacteria, denitrifying bacteria and phosphate accumulating bacteria; wherein,

[0065] The nitrifying bacteria are used to oxidize ammonia nitrogen in sewage into nitrite and nitrate;

[0066] The denitrifying bacteria are used to reduce nitrate in sewage to nitrogen gas under anoxic or anaerobic conditions;

[0067] The polyphosphate bacteria are used to absorb dissolved phosphorus in sewage under aerobic conditions and convert it into polyphosphate; and decompose the generated polyphosphate under anaerobic conditions and release it into the surrounding environment.

[0068] Furthermore, the ratio of nitrifying bacteria to phosphate-accumulating bacteria is adjusted according to the molar ratio of nitrogen to phosphorus in the sewage to ensure that the removal efficiency of nitrogen and phosphorus matches. At the same time, the ratio of nitrifying bacteria to denitrifying bacteria remains equal, which ensures that the nitrate produced by the nitrification process can be effectively reduced to nitrogen gas by denitrifying bacteria, avoiding the accumulation of nitrate in the system.

[0069] The following describes the principles by which specific microorganisms remove nitrogen and phosphorus from wastewater through their respective biological metabolic processes.

[0070] Nitrifying bacteria are the pioneers in this process. They convert ammonia nitrogen (NH4 + ) is converted into nitrite (NO2 - ) and further converted into nitrate (NO3 - ). This oxidation process not only reduces the toxicity of ammonia nitrogen, but also provides the necessary substrate for denitrifying bacteria.

[0071] Subsequently, denitrifying bacteria work under anoxic or anaerobic conditions, reducing nitrates to harmless nitrogen gas (N2). Through this process, nitrogen in the sewage is completely removed, thus completing the denitrification process.

[0072] Under aerobic conditions, polyphosphate bacteria absorb and store dissolved phosphorus in sewage through the polyphosphate synthase system in their cells, convert it into polyphosphate, and form polyphosphate particles in the cells. This process is called biological phosphorus removal or microbial phosphorus removal, which enables polyphosphate bacteria to accumulate large amounts of phosphorus under aerobic conditions.

[0073] When the environmental conditions change to anaerobic, polyphosphate bacteria begin to decompose the previously stored polyphosphates, release phosphorus, and use the energy generated in this process to survive and reproduce. This cycle of phosphorus absorption and release under aerobic and anaerobic conditions enables polyphosphate bacteria to effectively remove phosphorus from sewage, reduce phosphorus discharge, and thus control the occurrence of eutrophication of water bodies.

[0074] Through the synergistic action of nitrifying bacteria, denitrifying bacteria and polyphosphate bacteria, the sewage treatment system can efficiently remove nitrogen and phosphorus from sewage. The water purification principle of these microorganisms not only improves the efficiency of sewage treatment, but also reduces dependence on chemical treatment methods, achieving a more environmentally friendly and sustainable sewage treatment goal.

[0075] In order to enhance the denitrification and phosphorus removal capabilities of the biofilm carrier, adsorption materials are also combined in the biofilm carrier. These materials enhance the removal capabilities of nitrogen and phosphorus compounds in sewage through their respective physical and chemical properties.

[0076] Exemplarily, the adsorption material includes: modified zeolite, activated carbon and nanomaterials; wherein,

[0077] The modified zeolite uses a cation exchange mechanism to absorb nitrate ions in sewage using positively charged groups on its surface;

[0078] The activated carbon adsorbs nitrates and phosphates in sewage through a high specific surface area;

[0079] The nanomaterial forms chemical bonds with phosphates in sewage through a chemical adsorption mechanism to remove phosphorus from the sewage.

[0080] The following describes the principle of adsorption materials to remove nitrogen and phosphorus from wastewater.

[0081] Modified zeolite is a natural or synthetic aluminosilicate material. After special treatment, its surface has positively charged groups, which can effectively adsorb nitrate ions (NO3 - ). This mechanism involves the charge attraction between the positive charges on the surface of the modified zeolite and the nitrate ions in the solution, thereby achieving nitrogen removal.

[0082] Activated carbon is known for its high specific surface area and porous structure, which enables it to provide a large number of adsorption sites to remove nitrates and phosphates from wastewater by physical adsorption. The adsorption of activated carbon does not involve chemical changes, but fixes pollutants on its surface through physical forces, thereby reducing the concentration of these compounds in the water.

[0083] Nanomaterials, such as metal oxides, form stable chemical bonds with phosphates in wastewater through a chemical adsorption mechanism. The high reactivity of this material enables it to chemically react with phosphates to form insoluble compounds, thereby achieving phosphorus removal.

[0084] In the above embodiment, the biofilm carrier can not only remove nitrogen and phosphorus through the metabolic activities of microorganisms, but also further improve the removal efficiency through physical and chemical adsorption. This method of combining biological treatment and physical and chemical adsorption provides a comprehensive and efficient solution for sewage treatment, which helps to achieve higher quality effluent standards while reducing overall operating costs and environmental impacts.

[0085] Step S13: Sedimentation and separation are performed on the sewage after treatment in the mixed reaction zone, and part of the sludge separated by sedimentation is returned to the mixed reaction zone to realize the recycling of the sludge.

[0086] Specifically, after being treated in the mixing and reaction zone, the sewage is directed to the sedimentation and separation facility, the purpose of which is to separate the sludge formed during the treatment process from the purified supernatant water. During the sedimentation and separation process, the sludge will settle at the bottom of the sedimentation tank through gravity sedimentation, while the treated supernatant water will remain in the upper layer.

[0087] In some embodiments, in order to maintain the activity and treatment efficiency of the biofilm carrier in the mixed reaction zone, the sludge separated by sedimentation is not completely removed, but 80% (by volume) is selected as return sludge and sent back to the mixed reaction zone. This return mechanism helps to maintain the number and activity of microorganisms in the reaction zone, because the return sludge contains a rich microbial population, which can continue to participate in the biological treatment process of sewage.

[0088] At the same time, in order to ensure the healthy operation of the treatment system and remove the accumulated excess solids and aged biofilm carriers, 10% to 30% (by volume) of the upper sewage after sedimentation separation will be discharged. This discharge ratio is set to balance the recycling of sludge and the removal of solids in the system, preventing excessive accumulation of solids from affecting the sewage treatment effect and the activity of the biofilm.

[0089] Step S14: filtering and disinfecting the water filtered out after the sedimentation separation to ensure that the effluent meets the sewage treatment standard.

[0090] In some embodiments, the water filtered out after precipitation separation is filtered and disinfected, including: using ultrafiltration or nanofiltration technology to further remove tiny suspended particles and soluble pollutants in the water; degrading organic matter in the water through an oxidation process of one or more combinations of ozone, hydrogen peroxide or ultraviolet rays.

[0091] Specifically, ultrafiltration or nanofiltration technology is used to remove tiny suspended particles and dissolved pollutants in water. These technologies use the screening effect of semi-permeable membranes to intercept suspended solids, microorganisms and some dissolved pollutants in water by physical screening, thereby improving water clarity and biosafety. Ultrafiltration and nanofiltration membranes have small pore sizes and can effectively intercept most bacteria and viruses while removing some organic matter and dissolved solids.

[0092] Next, in order to further degrade the organic matter in the water that is difficult to biodegrade and improve the chemical stability and sensory quality of the effluent, an oxidation process combining one or more of ozone, hydrogen peroxide or ultraviolet light is used. Ozone is a strong oxidant that can effectively oxidize and decompose organic matter in the water, while also killing microorganisms in the water. Hydrogen peroxide can also produce strong oxidizing properties under the action of a catalyst to decompose organic pollutants in the water. Ultraviolet disinfection achieves the effect of sterilization and disinfection by destroying the DNA structure of microorganisms.

[0093] These advanced oxidation processes can be used alone or in combination to suit different water quality conditions and treatment requirements. For example, the combination of ozone and hydrogen peroxide can improve oxidation efficiency, while ultraviolet light can be used as a final disinfection guarantee. The combined application of these filtration and disinfection technologies ensures that the effluent quality after sewage treatment meets or exceeds sewage treatment standards and is suitable for safe discharge or further reuse. The optimization and implementation of this post-treatment process is an important guarantee for achieving the integrity of the sewage treatment process and the safety of the effluent.

[0094] It should be particularly noted that the process or method represented by the flowchart of the above embodiment of the present disclosure can be understood as representing a module, fragment or part of a code including one or more sets of executable instructions configured to implement the steps of a specific logical function or process. And the scope of the preferred embodiment of the present disclosure includes other implementations, in which the functions may not be performed in the order shown or discussed, including performing the functions in a substantially simultaneous manner or in a reverse order according to the functions involved.

[0095] like Figure 3 , Figure 4 As shown, the sewage treatment system for nitrogen and phosphorus removal disclosed in the present invention comprises: a pretreatment zone, a mixing reaction zone, a sedimentation zone and a post-treatment zone, wherein:

[0096] The pre-treatment area is used to remove large particles and suspended matter in the sewage by setting a grid and a grit chamber.

[0097] Specifically, the pretreatment area is the starting point of the entire process. Its main function is to remove large particles and suspended solids in the sewage by setting up screens and grit chambers. The screens serve as primary filtration devices to intercept and remove larger solids that may be contained in the sewage, such as branches and plastic bags, to prevent these substances from causing damage or clogging to subsequent treatment equipment. The grit chamber further removes particles with larger specific gravity, such as sand and gravel. If these particles are not removed, they may accumulate in the subsequent treatment process, affecting the sedimentation effect and biological treatment efficiency.

[0098] The mixed reaction zone is connected to the pretreatment zone and is provided with a biofilm carrier for removing nitrogen and phosphorus from the pretreated sewage.

[0099] Specifically, the pretreated sewage then flows into the mixed reaction zone, which is the core of sewage treatment and contains biofilm carriers. The biofilm carriers provide an environment for microorganisms to attach and grow, allowing specific microorganisms such as nitrifying bacteria, denitrifying bacteria and polyphosphate bacteria to form biofilms on their surfaces. Through their own metabolic activities, these microorganisms convert ammonia nitrogen in sewage into nitrates, which are then reduced to nitrogen gas. At the same time, they absorb dissolved phosphorus and convert it into polyphosphates, achieving the purpose of denitrification and dephosphorization.

[0100] The sedimentation zone is connected to the mixed reaction zone and is used for sedimentation and separation of the sewage treated in the mixed reaction zone.

[0101] Specifically, the sewage that has completed biological treatment then flows into the sedimentation zone, which is connected to the mixed reaction zone and has the function of solid-liquid separation. In the sedimentation zone, the sewage that has undergone biological treatment is subjected to gravity, causing the suspended biological flocs and sludge particles to settle to the bottom. The sedimentation zone is usually designed as a rectangular trough to optimize the water flow distribution and sedimentation efficiency. The sludge accumulated at the bottom of the sedimentation zone can be partially returned to the mixed reaction zone through the sludge return system to maintain the activity of the biofilm and the concentration of microorganisms, while the supernatant is used as treated water and can be subsequently filtered and disinfected, or directly discharged.

[0102] The post-treatment area is connected to the sedimentation area and is used to filter and disinfect the water filtered out after sedimentation separation.

[0103] Specifically, the post-treatment area is a key link to ensure that the effluent quality meets the established standards. It is directly connected to the sedimentation area and is responsible for further filtering and disinfecting the filtered water after sedimentation separation. This area is designed to remove residual tiny suspended particles, dissolved pollutants and organic matter to ensure the safety and clarity of the final effluent.

[0104] In some embodiments, the post-treatment zone includes: an advanced oxidation unit and a membrane bioreactor unit, wherein the advanced oxidation unit is used to integrate an ozone generator and a catalyst to degrade organic matter in the water; and the membrane bioreactor unit is used for solid-liquid separation to improve the clarity of the effluent.

[0105] Specifically, the advanced oxidation unit integrates an ozone generator and a catalyst to utilize the strong oxidizing property of ozone to degrade organic matter that is difficult to biodegrade in water. The hydroxyl radicals generated by the reaction of ozone with organic matter are very active oxidants that can efficiently mineralize organic pollutants and convert them into harmless carbon dioxide and water, thereby significantly improving water quality.

[0106] Meanwhile, the membrane bioreactor (MBR) unit plays a vital role in the post-treatment area. MBR technology combines biological treatment and membrane filtration to achieve solid-liquid separation through microfiltration or ultrafiltration membranes. This membrane filtration process can effectively intercept microorganisms and suspended solids, making the effluent clearer while reducing the use of disinfectants because membrane filtration has removed most potential sources of microbial contamination. The MBR unit not only improves the clarity of the effluent, but also enhances the efficiency of biological treatment by extending the sludge age.

[0107] Through the synergistic effect of the advanced oxidation unit and the membrane bioreactor unit, the post-treatment area can ensure that the effluent quality after sewage treatment meets or even exceeds the sewage treatment standards, and is suitable for safe discharge, agricultural irrigation or industrial reuse. This integrated post-treatment process not only improves the efficiency and effluent quality of sewage treatment, but also helps to reduce the use of chemicals, reduce operating costs, and achieve sustainable development of sewage treatment.

[0108] In some embodiments, the wastewater treatment system for nitrogen and phosphorus removal further includes: a monitoring module, disposed in the post-treatment area, for real-time monitoring of nitrogen and phosphorus content of water in the post-treatment area.

[0109] Specifically, the monitoring module is set up in the post-treatment area, and its core function is to monitor the nitrogen and phosphorus content in the treated water in real time. By using high-precision sensors and analytical instruments, the monitoring module can continuously collect data on the nitrogen and phosphorus concentrations in the effluent, which is crucial for evaluating the efficiency and effectiveness of the entire sewage treatment process.

[0110] The data collection and analysis capabilities of the monitoring module enable operators to understand the treatment effect in a timely manner and adjust system operating parameters based on real-time data, such as the aeration volume of the biological reaction zone, the sludge return ratio or the amount of chemical additives added. This real-time monitoring and adjustment mechanism not only ensures that the effluent quality always meets the predetermined sewage treatment standards, but also helps to optimize the operating efficiency of the entire system and reduce energy consumption and the use of chemicals.

[0111] In addition, the monitoring module can also be combined with the system's automatic control system to achieve data-driven intelligent decision-making. For example, when the concentration of nitrogen or phosphorus in the effluent is detected to exceed the preset threshold, the system can automatically adjust the operating parameters or initiate an emergency plan to respond quickly and ensure the quality of the effluent. This intelligent monitoring and control strategy not only improves the reliability and stability of the sewage treatment system, but also provides strong technical support for achieving more refined and sustainable sewage treatment.

[0112] In summary, the present invention discloses an efficient method and system for treating wastewater for nitrogen and phosphorus removal, which achieves wastewater purification through a series of continuous treatment steps. The pretreatment area removes large particulate matter and suspended solids through a grid and a grit chamber. Subsequently, the wastewater enters a mixed reaction zone containing a biofilm carrier, where nitrogen and phosphorus are removed using adsorption materials and specific microorganisms (such as nitrifying bacteria, denitrifying bacteria, and polyphosphate bacteria). The sedimentation zone precipitates and separates the wastewater treated in the mixed reaction zone, and part of the sludge is returned for recycling. The post-treatment area uses ultrafiltration or nanofiltration technology and ozone, hydrogen peroxide or ultraviolet oxidation processes to further purify the water quality. The system also includes a monitoring module to monitor the nitrogen and phosphorus content in the effluent in real time to ensure the treatment effect. In addition, the post-treatment area integrates an advanced oxidation unit and a membrane bioreactor unit to degrade organic matter and improve the clarity of the effluent. The entire system is designed to improve wastewater treatment efficiency, reduce energy consumption, and achieve environmentally friendly and sustainable wastewater treatment.

[0113] The above embodiments are merely illustrative of the principles and effects of the present disclosure, and are not intended to limit the present disclosure. Anyone familiar with the technology may modify or change the above embodiments without violating the spirit and scope of the present disclosure. Therefore, all equivalent modifications or changes made by a person of ordinary skill in the art without departing from the spirit and technical ideas disclosed in the present disclosure shall still be covered by the claims of the present disclosure.

Claims

1. A wastewater treatment method for denitrification and dephosphorization, characterized in that: include: Pre-treat the sewage by installing screens and grit chambers to remove large particles and suspended solids in the sewage; The pretreated sewage is introduced into a mixed reaction zone provided with a biofilm carrier to remove nitrogen and phosphorus from the sewage; The sewage treated in the mixed reaction zone is precipitated and separated, and the sludge separated by precipitation is partially returned to the mixed reaction zone to realize the recycling of sludge; The water filtered out after sedimentation separation is filtered and disinfected to ensure that the effluent meets sewage treatment standards.

2. The wastewater treatment method for denitrification and dephosphorization according to claim 1, characterized in that: The biofilm carrier in the mixed reaction zone includes: Adsorbent materials for removing nitrogen and phosphorus compounds from wastewater by physical or chemical adsorption; Specific microorganisms are attached to the biofilm carrier and form a biofilm, which is used to degrade nitrogen and phosphorus compounds in sewage through biological metabolic processes.

3. The wastewater treatment method for denitrification and dephosphorization according to claim 2, characterized in that: The adsorption material includes: modified zeolite, activated carbon and nanomaterials; wherein, The modified zeolite uses a cation exchange mechanism to absorb nitrate ions in sewage using positively charged groups on its surface; The activated carbon adsorbs nitrates and phosphates in sewage through a high specific surface area; The nanomaterial forms chemical bonds with phosphates in sewage through a chemical adsorption mechanism to remove phosphorus from the sewage.

4. The wastewater treatment method for denitrification and dephosphorization according to claim 2, characterized in that: The biofilm carrier includes: nitrifying bacteria, denitrifying bacteria and polyphosphate bacteria; wherein, The nitrifying bacteria are used to oxidize ammonia nitrogen in sewage into nitrite and nitrate; The denitrifying bacteria are used to reduce nitrate in sewage to nitrogen gas under anoxic or anaerobic conditions; The polyphosphate bacteria are used to absorb dissolved phosphorus in sewage under aerobic conditions and convert it into polyphosphate; and decompose the generated polyphosphate under anaerobic conditions and release it into the surrounding environment.

5. The wastewater treatment method for denitrification and dephosphorization according to claim 4, characterized in that: The ratio of the nitrifying bacteria to the polyphosphate bacteria is equal to the molar ratio of nitrogen to phosphorus in the sewage; The ratio of the nitrifying bacteria to the denitrifying bacteria is equal to ensure that the nitrate produced by nitrification can be reduced to nitrogen gas.

6. The wastewater treatment method for denitrification and dephosphorization according to claim 1, characterized in that: The sewage treated in the mixed reaction zone is subjected to sedimentation separation, and the sludge separated by sedimentation is partially returned to the mixed reaction zone to realize the recycling of the sludge, including: During the sedimentation separation process, 80% (by volume) of the sludge separated by sedimentation is returned to the mixing reaction zone to promote the continuous activity of the biofilm carrier; Discharge 10% to 30% (by volume) of the upper sewage after sedimentation separation to remove excess solids and aged biofilm carriers accumulated during the treatment process.

7. The wastewater treatment method for denitrification and dephosphorization according to claim 1, characterized in that: The filtering and disinfecting of the water filtered out after the precipitation separation comprises: Use ultrafiltration or nanofiltration technology to further remove tiny suspended particles and dissolved pollutants from water; Degradation of organic matter in water through an oxidation process using one or a combination of ozone, hydrogen peroxide or ultraviolet light.

8. A sewage treatment system for nitrogen and phosphorus removal, characterized in that: include: Pre-treatment area, used to remove large particles and suspended solids from sewage by setting screens and grit chambers; A mixing reaction zone, connected to the pretreatment zone, provided with a biofilm carrier for removing nitrogen and phosphorus from the pretreated sewage; The sedimentation zone is connected to the mixing reaction zone and is used for sedimentation separation of the sewage after treatment in the mixing reaction zone; the post-treatment zone is connected to the sedimentation zone and is used for filtering and disinfecting the water filtered out after sedimentation separation.

9. The sewage treatment system for nitrogen and phosphorus removal according to claim 8, characterized in that: Also includes: The monitoring module is arranged in the post-processing area and is used for real-time monitoring of the nitrogen and phosphorus content of the water in the post-processing area.

10. The sewage treatment system for nitrogen and phosphorus removal according to claim 8, characterized in that: The post-processing area includes: Advanced oxidation units, which integrate ozone generators and catalysts to degrade organic matter in water; Membrane bioreactor unit for solid-liquid separation to improve effluent clarity.

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