Integrated device for removing phosphorus and nitrogen
By integrating denitrification, aeration for phosphorus removal, and anaerobic ammonia oxidation modules, the organic matter and magnesium hydroxide in the wastewater are used to generate struvite precipitate, which solves the problems of high energy consumption and phosphate precipitation in the anaerobic ammonia oxidation process and achieves low-cost and high-efficiency phosphorus and nitrogen removal.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- 柏中环境科技(上海)股份有限公司
- Filing Date
- 2025-06-24
- Publication Date
- 2026-06-23
AI Technical Summary
Existing anaerobic ammonia oxidation processes have high aeration energy consumption and high operating costs when treating high COD wastewater, and cannot effectively solve the problem of phosphate precipitation caused by high phosphate influent, resulting in complex process flow and increased costs.
An integrated phosphorus and nitrogen removal device was designed, comprising a denitrification module, an aeration phosphorus removal module, and an anaerobic ammonia oxidation module. The device utilizes organic matter in the wastewater as a carbon source for denitrification. Magnesium hydroxide is added through the aeration phosphorus removal module to generate struvite precipitate, thereby removing phosphate and converting ammonia nitrogen into nitrogen gas.
It achieves one-stop, high-efficiency phosphorus and nitrogen removal with low energy consumption, reduces operating costs, simplifies the process, and the generated struvite precipitate can be recycled and reused, meeting the high total nitrogen emission standards.
Smart Images
Figure CN224394703U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of water treatment technology, and in particular to an integrated phosphorus and nitrogen removal device. Background Technology
[0002] Currently, the A / O process is the mainstream biological nitrogen removal technology for wastewater. This process achieves nitrogen removal through the synergistic action of an anoxic (A) and aerobic (O) stage: the anoxic stage utilizes denitrifying bacteria to reduce nitrate nitrogen to nitrogen gas; the aerobic stage removes organic matter and converts ammonia nitrogen into nitrate nitrogen. During operation, the mixed liquor from the aerobic stage is returned to the anoxic stage to complete the nitrogen removal process. This process preferentially utilizes biodegradable organic matter in the raw water as a carbon source for denitrification. When the C / N ratio of the influent is insufficient, additional carbon source needs to be added, increasing treatment costs.
[0003] With the development of biotechnology, anaerobic ammonia oxidation (ANAO) technology has been increasingly applied in the field of biological nitrogen removal from wastewater. This process utilizes anaerobic ammonia-oxidizing bacteria to directly convert ammonia nitrogen and nitrite nitrogen into nitrogen gas. The reaction equation is as follows: 1NH4+ + +1.32NO2 - +0.066HCO3 - +0.13H + →1.02N2+0.26NO3 - +0.066CH2O 0.5 N 0.15 +2.03H2O
[0004] Compared to the A / O method, it has advantages such as lower carbon dioxide emissions, no need for external carbon sources, smaller footprint, and lower aeration volume. In engineering, it is divided into a single-stage method (nitrification and anaerobic ammonia oxidation in the same reactor) and a two-stage method (separately placed in two reactors). However, this process has stringent requirements for controlling influent organic matter and phosphate levels, and the residual nitrate nitrogen after treatment limits the total nitrogen removal, making it difficult to meet high total nitrogen emission requirements.
[0005] Existing anammox combined systems have significant drawbacks: When treating high-COD wastewater, high-load aeration combined with anammox results in high aeration energy consumption and high operating costs. Furthermore, the anammox effluent requires subsequent denitrification due to residual nitrate nitrogen, and denitrification further consumes carbon sources if used. In denitrification-nitrification reactor combined with anammox reactor systems, denitrification relies on microbial degradation of carbon sources; insufficient carbon sources lead to incomplete reactions, increasing costs and causing residual COD in the effluent. This can trigger excessive growth of heterotrophic bacteria within the anammox reactor, resulting in a higher proportion of heterotrophic bacteria than anammox bacteria, leading to bioinhibition. Additionally, neither type of combined system can solve the phosphate precipitation problem caused by high phosphate influent. Precipitates such as magnesium ammonium phosphate and calcium phosphate form crystal nuclei. Due to the presence of these inorganic nuclei, newly generated anammox microorganisms attach to them, making the anammox sludge prone to sandification and loss of activity. An additional phosphorus removal process is required, complicating the process flow and increasing costs. Utility Model Content
[0006] To address the above technical problems, this utility model discloses an integrated phosphorus and nitrogen removal device, which solves the problems of COD and phosphate in ammonia nitrogen wastewater with low C / N ratio. It fully utilizes the advantages of low-energy denitrification of anaerobic ammonia oxidation, solves the problem of residual nitrate nitrogen in anaerobic ammonia oxidation effluent requiring further deep denitrification, requires no additional carbon source, greatly reduces the operating cost of biological denitrification, and achieves one-stop high-efficiency phosphorus and nitrogen removal.
[0007] The technical solution adopted by this utility model is as follows:
[0008] An integrated phosphorus and nitrogen removal device includes a denitrification module, an aeration phosphorus removal module, and an anaerobic ammonia oxidation module. The aeration phosphorus removal module and the anaerobic ammonia oxidation module are located above the denitrification module, and the aeration phosphorus removal module is located outside the anaerobic ammonia oxidation module. The denitrification module is provided with an inlet pipe, and the anaerobic ammonia oxidation module is provided with an outlet pipe. The denitrification module is connected to the aeration phosphorus removal module through the denitrification outlet pipe, and the aeration phosphorus removal module is connected to the anaerobic ammonia oxidation module through the aeration phosphorus removal outlet pipe. The anaerobic ammonia oxidation module is connected to the denitrification module through a return water inlet pipe. The aeration phosphorus removal module is provided with a magnesium hydroxide dosing pipe for adding magnesium hydroxide for phosphorus removal.
[0009] The denitrification module utilizes readily biodegradable organic matter in the wastewater as a carbon source to reduce nitrate nitrogen into nitrogen gas, while simultaneously removing most of the organic matter from the incoming water. The aeration and phosphorus removal module provides high-load aeration and phosphorus removal; magnesium hydroxide is added to the module via a magnesium hydroxide dosing pipe, utilizing the aeration to provide stirring energy. Under high stirring intensity, the phosphate and ammonium ions in the water react with magnesium using the struvite precipitation principle to form magnesium ammonium phosphate (struvite), solving the phosphate problem in the incoming water and reducing the ammonia nitrogen load in the subsequent anaerobic ammonia oxidation module. The generated struvite precipitate can be extracted and processed further and sold as a slow-release fertilizer, possessing economic value and enabling resource recycling. The anaerobic ammonia oxidation module converts ammonia nitrogen in the wastewater into nitrogen gas.
[0010] Using this technology, high-ammonia wastewater carrying organic matter and phosphates flows sequentially through a denitrification module, an aeration phosphorus removal module, and an anaerobic ammonia oxidation module, ultimately achieving low-energy, one-stop, high-efficiency phosphorus and nitrogen removal. The integrated design shortens the process flow, significantly reduces the floor space required, and minimizes investment.
[0011] As a further improvement of this utility model, the denitrification module includes a denitrification cylinder, which is provided with a denitrification water distributor, a flow guide cylinder, a denitrification three-phase separator, and a denitrification water collection pipe from bottom to top. The bottom two sides of the denitrification cylinder are respectively connected to an inlet pipe and a circulating water pipe, and the circulating water pipe is connected to the inlet pipe through a circulating pump. The inlet pipe is connected to the denitrification water distributor. The top of the denitrification cylinder is connected to a denitrification exhaust pipe and a denitrification outlet pipe.
[0012] Using this technology, high-ammonia wastewater containing a certain amount of organic matter and phosphate enters the denitrification module through the inlet pipe. It is then sprayed vertically upwards at high speed by the denitrification distributor, creating an upward flow within the guide tube. This high-speed water flow forms a negative pressure zone at the bottom of the guide tube, drawing in water from outside the tube, which then flows upwards together with the water sprayed from the denitrification distributor within the guide tube. A circulating pump draws in water from outside the guide tube, pressurizes it, and then connects it to the inlet pipe via a circulating water pipe. Simultaneously, return water from the anaerobic ammonia oxidation module is also incorporated into the inlet pipe. Inside the denitrification tube, nitrate nitrogen in the return water from the anaerobic ammonia oxidation module and organic matter in the incoming water undergo denitrification removal under the action of the denitrifying sludge. Under the action of the denitrification three-phase separator, the gas, liquid and solid phases in the denitrification cylinder are separated into three phases; the nitrogen gas produced by denitrification is discharged into the atmosphere through the denitrification exhaust pipe; the denitrification effluent is collected through the denitrification water collection pipe and then enters the aeration phosphorus removal module through the denitrification effluent pipe; the denitrification sludge is returned to the denitrification cylinder under the action of gravity to continue the reaction.
[0013] As a further improvement of this utility model, a denitrification dosing pipe is connected to the lower middle part of the denitrification cylinder, the denitrification dosing pipe extends into the denitrification cylinder and communicates with the guide cylinder; an online denitrification pH meter is provided in the middle of the denitrification cylinder; and a denitrification sludge discharge pipe is provided at the bottom of the denitrification cylinder. Considering that alkalinity is generated during the denitrification process, the online denitrification pH meter in the middle of the denitrification cylinder can monitor the pH of the mixed liquor in the denitrification cylinder in real time. When the pH is high, acid is added through the denitrification dosing pipe to adjust the pH range to 6.5-7.5. In addition, since denitrifying bacteria will proliferate during the denitrification process, in order to maintain the concentration of biological sludge in the denitrification zone, excess biological sludge can be discharged through the denitrification sludge discharge pipe.
[0014] As a further improvement of this utility model, the denitrification water distributor is located at the bottom of the guide tube, and the denitrification three-phase separator is located above the guide tube.
[0015] As a further improvement of this utility model, the denitrification water distributor is provided with a plurality of vertically upward nozzles, and the nozzles are located inside the bottom of the guide tube.
[0016] As a further improvement of this utility model, the distance between the denitrification three-phase separator and the guide tube is 500-1000mm. Using this technical solution, the effluent from the guide tube can overflow through this gap, and a portion of the effluent flows downwards to fill the space at the bottom where the wastewater drawn into the guide tube flows away, forming a flow pattern that moves up and down along the inside and outside of the guide tube. This allows the denitrifying biological sludge and wastewater inside the denitrification tube to mix and react fully. At this time, the nitrate nitrogen in the return water is reduced to nitrogen gas by the denitrifying bacteria using easily biodegradable organic matter in the wastewater as a carbon source, while simultaneously removing most of the organic matter from the incoming water.
[0017] As a further improvement of this utility model, the aeration phosphorus removal module is arranged circumferentially around the anaerobic ammonia oxidation module.
[0018] As a further improvement of this utility model, the aeration phosphorus removal module includes an aeration phosphorus removal cylinder. The bottom of the aeration phosphorus removal cylinder is provided with an aeration phosphorus removal water distribution pipe connected to the denitrification effluent pipe. An aeration phosphorus removal aerator is installed inside the aeration phosphorus removal cylinder, located above the aeration phosphorus removal water distribution pipe and connected to the aeration phosphorus removal air pipe. An aeration phosphorus removal guide cylinder is located above the aeration phosphorus removal aerator, and an aeration phosphorus removal three-phase separator is located above the aeration phosphorus removal guide cylinder. A magnesium hydroxide dosing pipe enters the aeration phosphorus removal guide cylinder. The inlet end of the aeration phosphorus removal effluent pipe is located at the top of the aeration phosphorus removal three-phase separator.
[0019] In this technical solution, effluent from the denitrification module enters the bottom of the aeration and phosphorus removal cylinder through the aeration and phosphorus removal water distribution pipe. Air enters the bottom of the aeration and phosphorus removal cylinder through the aeration and phosphorus removal air pipe and is evenly distributed into the water by the aerator, providing dissolved oxygen for the activated sludge inside the aeration and phosphorus removal cylinder. This allows residual organic matter in the influent to be degraded by heterotrophic bacteria. After aeration, the medium density inside the aeration and phosphorus removal guide cylinder is lower than that outside, forming a high-speed circulation and providing high stirring energy to promote the formation of magnesium ammonium phosphate (struvite). The water, air, and sludge inside the aeration and phosphorus removal cylinder flow upwards into the aeration and phosphorus removal three-phase separator to achieve three-phase separation. Excess air escapes along the water surface. The effluent from the aeration and phosphorus removal cylinder is discharged to the anaerobic ammonia oxidation module through the aeration and phosphorus removal effluent pipe. The sludge inside the aeration and phosphorus removal cylinder falls to the bottom of the aeration and phosphorus removal three-phase separator under gravity and then falls back into the aeration and phosphorus removal cylinder to continue participating in the reaction.
[0020] As a further improvement of this utility model, the aeration phosphorus removal module includes an aeration phosphorus removal sludge discharge pipe, which is connected to the aeration phosphorus removal cylinder. Using this technical solution, the microbial proliferation sludge produced from COD degradation and the generated struvite crystals form a mixed sludge, which can be discharged through the aeration phosphorus removal sludge discharge pipe.
[0021] As a further improvement of this utility model, the aeration phosphorus removal module includes an online dissolved oxygen (DO) meter, which is inserted below the liquid level inside the aeration phosphorus removal cylinder. This technical solution allows for real-time monitoring of the dissolved oxygen concentration in the aeration phosphorus removal cylinder, thereby controlling the air volume in the aeration phosphorus removal air pipe.
[0022] As a further improvement of this utility model, the aeration phosphorus removal aerator is a coarse-pore aerator, which can avoid excessive dissolved oxygen while meeting the stirring capacity requirements.
[0023] As a further improvement of this utility model, the anaerobic ammonia oxidation module includes an anaerobic ammonia oxidation cylinder and a water collection cylinder. An anaerobic ammonia oxidation water distribution pipe is located at the bottom of the anaerobic ammonia oxidation cylinder and is connected to an aeration phosphorus removal effluent pipe. An anaerobic ammonia oxidation aerator is located above the water distribution pipe and is connected to an anaerobic ammonia oxidation air pipe. An anaerobic ammonia oxidation three-phase separator is located in the upper middle part of the anaerobic ammonia oxidation cylinder. An anaerobic ammonia oxidation effluent pipe is located at the top of the three-phase separator and is connected to the water collection cylinder. The upper part of the water collection cylinder is connected to the effluent pipe. The bottom of the water collection cylinder is connected to a return water inlet pipe via an effluent return pipe. A heat exchange tube is located inside the anaerobic ammonia oxidation cylinder, with its two ends connected to a hot water inlet pipe and a hot water return pipe, respectively. An anaerobic ammonia oxidation pH dosing pipe and a trace element dosing pipe are located at the top of the anaerobic ammonia oxidation cylinder. The trace elements required by the anaerobic ammonia oxidation microorganisms are added into the anaerobic ammonia oxidation cylinder through the trace element dosing tube.
[0024] In this technical solution, effluent from the aeration and phosphorus removal outlet pipe enters the anammox cylinder through the anammox water distribution pipe. Air enters the bottom of the anammox cylinder through the anammox air pipe and is evenly distributed into the water via the anammox aerator, providing oxygen for the nitrification of ammonia nitrogen in the anammox granular sludge within the cylinder and simultaneously mixing the wastewater and granular sludge. Under the action of anammox bacteria, ammonia nitrogen in the wastewater is ultimately converted into nitrogen gas, while a portion of nitrate nitrogen is generated. Inside the anammox cylinder, water, gas, and sludge flow upwards together, where they undergo three-phase separation in the anammox three-phase separator. Gas escapes from the water surface, while the anammox granular sludge returns to the anammox cylinder to continue participating in the reaction. The effluent is discharged into the collection tank. The collection tank provides a buffer space for the effluent and further removes gas from the water, preventing cavitation of the subsequent booster pump. The bottom of the water collection cylinder is connected to a return water pipe, and the top overflows to allow the final effluent to be discharged outside the system through the outlet pipe. Considering that anaerobic ammonia oxidizing bacteria have high activity at temperatures of 30-40℃ and low activity below 35℃, the water temperature in the anaerobic ammonia oxidizing cylinder can be controlled by heating when the water temperature is low. Hot water is connected to the heat exchange pipe from the hot water inlet pipe. After heat exchange, the water temperature decreases and then flows back to the external heating system through the hot water return pipe.
[0025] As a further improvement of this utility model, the anammox module includes an online anammox thermometer, an online anammox pH meter, and an online anammox DO meter, which are inserted below the liquid surface inside the anammox cylinder. Using this technical solution, the online anammox thermometer can monitor the water temperature inside the anammox cylinder in real time and can be linked to control an external heating system or hot water valve to adjust the water temperature. The one-stage anammox method used in the anammox module includes a nitrification reaction, thus consuming alkalinity. The online anammox pH meter can monitor the pH of the mixed solution inside the anammox cylinder in real time, and the pH value of the solution can be controlled by controlling the addition of alkali solution through the anammox dosing pipe. Based on the feedback from the online DO meter, the air supply in the anammox air pipe can be adjusted to control dissolved oxygen.
[0026] As a further improvement of this utility model, a booster pump is provided between the outlet return pipe and the return water inlet pipe.
[0027] As a further improvement of this utility model, the bottom of the water collecting cylinder is inverted conical.
[0028] As a further improvement of this utility model, the anaerobic ammonia oxidation aerator is a microporous aerator.
[0029] As a further improvement of this utility model, the diameter of the denitrification cylinder is the same as that of the anaerobic ammonia oxidation cylinder, and is smaller than the outer diameter of the aeration phosphorus removal cylinder.
[0030] As a further improvement of this utility model, the bottom of the aeration phosphorus removal cylinder is inverted conical.
[0031] As a further improvement of this utility model, the integrated phosphorus and nitrogen removal system includes a control module. The outlet of the denitrification dosing pipe is connected to a denitrification dosing control valve. The aeration phosphorus removal air pipe is connected to an aeration phosphorus removal air control valve. The hot water inlet pipe is connected to a hot water valve, or the inlet end of the hot water inlet pipe is equipped with a heating thermostat. The outlet of the anammox pH dosing pipe is connected to an anammox pH dosing control valve. The control module is electrically connected to the online denitrification pH meter, the online aeration phosphorus removal DO meter, the online anammox thermometer, the online anammox pH meter, the online anammox DO meter, the denitrification dosing control valve, the aeration phosphorus removal air control valve, the hot water valve or the heating thermostat, and the anammox pH dosing control valve. Using this technical solution, the control module can monitor the pH of the liquid inside the denitrification tank in real time through the online denitrification pH meter, adjust the amount of acid added in the denitrification dosing pipe, and control the pH of the liquid inside the denitrification tank to 6.5–7.5; based on the feedback from the online DO meter for phosphorus removal, it can adjust the air supply in the air pipe for phosphorus removal, and control the dissolved oxygen level in the liquid inside the aeration and phosphorus removal tank to 0.3–0.5 mg / L; based on the feedback from the online thermometer for anaerobic ammonia oxidation, it can adjust... The hot water inlet pipe controls the water temperature of the liquid inside the anaerobic ammonia oxidation cylinder to be 33-38℃; based on the feedback from the online pH meter for anaerobic ammonia oxidation, the dosage in the pH dosing pipe for anaerobic ammonia oxidation is adjusted to control the pH of the liquid inside the anaerobic ammonia oxidation cylinder to be 7.5-8.0; based on the feedback from the online DO meter for anaerobic ammonia oxidation, the air supply in the air pipe for anaerobic ammonia oxidation is adjusted to control the dissolved oxygen in the liquid inside the anaerobic ammonia oxidation cylinder to be below 0.3 mg / L.
[0032] Compared with the prior art, the beneficial effects of this utility model are as follows:
[0033] First, efficient utilization of carbon source. The technical solution of this utility model makes full use of the nitrate nitrogen produced by the reduction of anaerobic ammonia oxidation reaction by organic matter in the wastewater, eliminating the need for additional carbon source addition and reducing operating costs.
[0034] Secondly, energy consumption is significantly reduced. Using the technical solution of this invention, the high-load aeration of the phosphorus removal module serves only as a safeguard for organic matter control. Since most readily biodegradable organic matter has already been removed during the preceding denitrification process, the aeration power consumption in this step is significantly reduced compared to directly treating the incoming water, resulting in an overall system power consumption reduction of 20%.
[0035] Third, simultaneous phosphorus removal and resource recovery. This invention's technical solution involves adding magnesium hydroxide to the aeration phosphorus removal module. Utilizing the aeration and stirring energy, and based on the principle of struvite precipitation, phosphate and ammonium ions react with magnesium ions to form magnesium ammonium phosphate precipitate. This process not only effectively removes phosphate from wastewater but also reduces the influent ammonia nitrogen load of the subsequent anaerobic ammonia oxidation module. Furthermore, the generated struvite precipitate can be extracted and sold as slow-release fertilizer, achieving resource recovery and utilization. The phosphorus removal operating cost is only 0.3 yuan per cubic meter of wastewater.
[0036] Fourth, deep denitrification and process simplification. The technical solution of this utility model has a low total nitrogen content in the effluent, eliminating the need for additional deep denitrification treatment and meeting the requirements of high total nitrogen discharge standards. The integrated design shortens the process flow, significantly reducing the footprint and investment costs. Taking wastewater with influent ammonia nitrogen of 1000 mg / L and phosphate of 200 mg / L as an example, the total nitrogen removal rate increases from 81.6% to 96%, and the operating cost is reduced by 1.10 yuan / cubic meter of wastewater, achieving one-stop, low-energy-consumption, and highly efficient deep phosphorus and nitrogen removal. Attached Figure Description
[0037] Figure 1 This is a schematic diagram illustrating the working principle of the integrated phosphorus and nitrogen removal device according to an embodiment of this utility model.
[0038] Figure 2 This is a schematic diagram of the integrated phosphorus and nitrogen removal device according to an embodiment of the present invention.
[0039] The reference numerals in the figures include:
[0040] 1-Denitrification module, 2-Aeration phosphorus removal module, 3-Anaerobic ammonium oxidation module;
[0041] 100-Denitrification cylinder, 101-Inlet pipe, 102-Denitrification water distributor, 103-Guide cylinder, 104-Circulating inlet pipe, 105-Circulating pump, 106-Circulating outlet pipe, 107-Denitrification three-phase separator, 108-Denitrification water collection pipe, 109-Denitrification outlet pipe, 110-Denitrification exhaust pipe, 111-Denitrification sludge discharge pipe, 112-Denitrification chemical dosing pipe, 113-Denitrification online pH meter;
[0042] 200-Aeration and phosphorus removal cylinder, 201-Aeration and phosphorus removal water distribution pipe, 202-Aeration and phosphorus removal air pipe, 203-Aeration and phosphorus removal aerator, 204-Aeration and phosphorus removal guide cylinder, 205-Aeration and phosphorus removal three-phase separator, 206-Aeration and phosphorus removal effluent pipe, 207-Magnesium hydroxide dosing pipe, 208-Aeration and phosphorus removal sludge discharge pipe, 209-Aeration and phosphorus removal online DO instrument;
[0043] 300-Anaerobic ammonia oxidation cylinder, 301-Anaerobic ammonia oxidation water distribution pipe, 302-Anaerobic ammonia oxidation air pipe, 303-Anaerobic ammonia oxidation aerator, 304-Anaerobic ammonia oxidation three-phase separator, 305-Anaerobic ammonia oxidation effluent pipe, 306-Water collection cylinder, 307-Effluent pipe, 308-Effluent return pipe, 309-Hot water inlet pipe, 310-Heat exchange pipe, 311-Hot water return pipe, 312-Anaerobic ammonia oxidation pH dosing pipe, 313-Trace element dosing pipe, 314-Anaerobic ammonia oxidation online thermometer, 315-Anaerobic ammonia oxidation online pH meter, 316-Anaerobic ammonia oxidation online DO meter, 317-Booster pump, 318-Return water inlet pipe. Detailed Implementation
[0044] The preferred embodiments of this utility model will be described in further detail below.
[0045] like Figure 1 and Figure 2 As shown, the integrated phosphorus and nitrogen removal device includes a denitrification module 1, an aeration phosphorus removal module 2, and an anaerobic ammonia oxidation module 3. These three modules form a reactor system. The denitrification module 1 is located below the reactor system, while the aeration phosphorus removal module 2 and the anaerobic ammonia oxidation module 3 are located above it, with the anaerobic ammonia oxidation module 3 directly above the denitrification module 1 and the aeration phosphorus removal module 2 surrounding it in a ring. The denitrification module 1 is connected to the aeration phosphorus removal module 2 via a denitrification effluent pipe 109, and the aeration phosphorus removal module 2 is connected to the anaerobic ammonia oxidation module 3 via an aeration phosphorus removal effluent pipe 206. The anaerobic ammonia oxidation module 3 is connected to the denitrification module 1 via a return water inlet pipe 318. The aeration phosphorus removal module 2 is equipped with a magnesium hydroxide dosing pipe 207 for adding magnesium hydroxide.
[0046] Specifically, the denitrification module 1 includes a denitrification cylinder 100, an inlet pipe 101, a circulating inlet pipe 104, a circulating pump 105, a circulating outlet pipe 106, a denitrification outlet pipe 109, a denitrification exhaust pipe 110, a denitrification sludge discharge pipe 111, a denitrification chemical dosing pipe 112, and a denitrification online pH meter 113. Inside the denitrification cylinder 100, from bottom to top, are arranged a denitrification water distributor 102, a guide cylinder 103, a denitrification three-phase separator 107, and a denitrification water collection pipe 108. The inlet pipe 101 is connected to the bottom of the denitrification cylinder 100. The circulating pump 105 is connected to the bottom of the denitrification cylinder 100 through the circulating inlet pipe 104 and the circulating outlet pipe 106. The denitrification exhaust pipe 110 is connected to the top of the denitrification cylinder 100; the denitrification sludge discharge pipe 111 is connected to the bottom of the denitrification cylinder 100; the denitrification dosing pipe 112 is located in the lower middle part of the denitrification cylinder 100 and is connected to the guide cylinder 103; the denitrification online pH meter 113 is connected to the middle part of the denitrification cylinder 100 and can monitor the pH of the liquid in the denitrification cylinder 100 in real time; the denitrification effluent pipe 109 is connected to the top of the denitrification cylinder 100; the inlet end of the denitrification water distributor 102 is connected to the inlet pipe 101, and its outlet end is a vertically upward nozzle located inside the bottom of the guide cylinder 103; the denitrification three-phase separator 107 is located on the upper part of the guide cylinder 103, and is 500-1000 mm away from the guide cylinder.
[0047] The aeration phosphorus removal module 2 includes an aeration phosphorus removal cylinder 200, an aeration phosphorus removal water distribution pipe 201, an aeration phosphorus removal air pipe 202, an aeration phosphorus removal aerator 203, an aeration phosphorus removal guide cylinder 204, an aeration phosphorus removal three-phase separator 205, an aeration phosphorus removal effluent pipe 206, a magnesium hydroxide dosing pipe 207, an aeration phosphorus removal sludge discharge pipe 208, and an online aeration phosphorus removal DO meter 209. The aeration phosphorus removal water distribution pipe 201 is located at the bottom of the aeration phosphorus removal cylinder 200 and is connected to the denitrification effluent pipe 111; the aeration phosphorus removal aerator 203 is located above the aeration phosphorus removal water distribution pipe 201 and is connected to the aeration phosphorus removal air pipe 202; the aeration phosphorus removal aerator 203 is a coarse-pore aerator. The aeration phosphorus removal guide tube 204 is located above the aeration phosphorus removal aerator 203; the aeration phosphorus removal three-phase separator 205 is located at the upper part of the aeration phosphorus removal cylinder 200 and above the aeration phosphorus removal guide tube 204. The inlet end of the aeration phosphorus removal outlet pipe 206 is located at the top of the aeration phosphorus removal three-phase separator 205, and its outlet end is connected to the anaerobic ammonia oxidation module 3. The magnesium hydroxide dosing pipe 207 enters the aeration phosphorus removal guide tube 204; the aeration phosphorus removal sludge discharge pipe 208 is connected to the bottom of the aeration phosphorus removal cylinder 200. The aeration phosphorus removal online DO meter 209 is inserted below the liquid level in the aeration phosphorus removal cylinder 200 and can interlock to adjust the air supply in the aeration phosphorus removal air pipe 202 to further control the dissolved oxygen at 0.3-0.5 mg / L.
[0048] The anaerobic ammonia oxidation module 3 includes an anaerobic ammonia oxidation cylinder 300, an anaerobic ammonia oxidation water distribution pipe 301, an anaerobic ammonia oxidation air pipe 302, an anaerobic ammonia oxidation aerator 303, an anaerobic ammonia oxidation three-phase separator 304, an anaerobic ammonia oxidation water outlet pipe 305, a water collection cylinder 306, a water outlet pipe 307, a water outlet return pipe 308, a hot water inlet pipe 309, a heat exchange pipe 310, a hot water return pipe 311, an anaerobic ammonia oxidation pH dosing pipe 312, a trace element dosing pipe 313, an anaerobic ammonia oxidation online thermometer 314, an anaerobic ammonia oxidation online pH meter 315, an anaerobic ammonia oxidation online DO meter 316, a booster pump 317, and a return water inlet pipe 318. The anammox water distribution pipe 301 is located at the bottom of the anammox cylinder 300 and is connected to the aeration phosphorus removal effluent pipe 206. The anammox aerator 303 is located above the anammox water distribution pipe 301 and is connected to the anammox air pipe 302. The anammox aerator 303 is a microporous aerator. The anammox three-phase separator 304 is located in the upper center of the anammox cylinder 300. The inlet end of the anammox effluent pipe 305 communicates with the top of the anammox three-phase separator 304, and its outlet end communicates with the water collection cylinder 306. The effluent pipe 307 communicates with the upper part of the water collection cylinder 306; the bottom of the water collection cylinder is inverted conical; and the effluent return pipe 308 communicates with the bottom of the water collection cylinder 306. The heat exchange tube 310 is located in the middle of the anammox cylinder 300, with its two ends connected to the hot water inlet pipe 309 and the hot water return pipe 311, respectively. The anammox pH dosing pipe 312 and the trace element dosing pipe 313 are connected to the upper part of the anammox cylinder 300. The anammox online thermometer 314, the anammox online pH meter 315, and the anammox online DO meter 316 are all inserted below the liquid surface inside the anammox cylinder 300. The anammox online thermometer 314 can be interlocked to adjust the hot water flow or temperature in the hot water inlet pipe 309, thereby controlling the water temperature inside the anammox cylinder 300. The anammox online pH meter 315 can be interlocked to adjust the dosage in the anammox pH dosing pipe 312 to adjust the pH range to 7.5–8.0. The anaerobic ammonia oxidation online DO meter 316 can be interlocked to adjust the air supply in the anaerobic ammonia oxidation air pipe 302 to control dissolved oxygen below 0.3 mg / L. The inlet side of the booster pump 317 is connected to the water collection cylinder 306 through the outlet return pipe 308, and its outlet side is connected to the denitrification module through the return water inlet pipe 318.
[0049] The diameter of the denitrification cylinder 100 is the same as that of the anaerobic ammonia oxidation cylinder 200, and smaller than the outer diameter of the aeration phosphorus removal cylinder 300. The bottom of the aeration phosphorus removal cylinder 300 is inverted conical.
[0050] Furthermore, the integrated phosphorus and nitrogen removal system includes a control module. The outlet of the denitrification dosing pipe 112 is connected to a denitrification dosing control valve. The aeration phosphorus removal air pipe 202 is connected to an aeration phosphorus removal air control valve. The hot water inlet pipe 309 is connected to a hot water valve, or the inlet end of the hot water inlet pipe 309 is equipped with a heating thermostat. The outlet of the anammox pH dosing pipe 312 is connected to an anammox pH dosing control valve. The control module is electrically connected to the online denitrification pH meter 113, the online aeration phosphorus removal DO meter 209, the online anammox thermometer 314, the online anammox pH meter 315, the online anammox DO meter 316, the denitrification dosing control valve, the aeration phosphorus removal air control valve, the hot water valve or the heating thermostat, and the anammox pH dosing control valve. Using this technical solution, the control module can monitor the pH of the liquid inside the denitrification cylinder in real time through the online denitrification pH meter 113, adjust the amount of acid added in the denitrification dosing pipe 112, and control the pH of the liquid inside the denitrification cylinder to 6.5-7.5; based on the feedback from the online phosphorus removal DO meter 209, it can adjust the air supply in the aeration phosphorus removal air pipe 202, and control the dissolved oxygen level of the liquid surface inside the aeration phosphorus removal cylinder to 0.3-0.5 mg / L; based on the feedback from the online anaerobic ammonia oxidation thermometer 314, it can adjust the hot water... The hot water volume or temperature of the inlet pipe 309 controls the water temperature of the liquid in the anaerobic ammonia oxidation cylinder 300 to be 33-38℃; based on the feedback from the online pH meter 315, the dosage in the pH dosing pipe 312 is adjusted to control the pH of the liquid in the anaerobic ammonia oxidation cylinder 300 to be 7.5-8.0; based on the feedback from the online DO meter 316, the air supply in the air pipe 302 is adjusted to control the dissolved oxygen in the liquid in the anaerobic ammonia oxidation cylinder 300 to be below 0.3 mg / L.
[0051] The workflow of the integrated phosphorus and nitrogen removal unit for treating high-ammonia wastewater containing organic matter and phosphate is as follows:
[0052] High-ammonia wastewater carrying certain amounts of organic matter and phosphate ions enters the denitrification cylinder 100 of the denitrification module 1 through the inlet pipe 101. It is then sprayed vertically upwards at high speed by the denitrification water distributor 102, forming an upward flow within the guide cylinder 103. The high-speed water flow creates a negative pressure zone at the bottom of the guide cylinder 103, drawing in water from outside the guide cylinder 103, which then flows upwards within the guide cylinder 103 together with the water sprayed from the denitrification water distributor 102. The circulation pump 105 draws water from outside the guide cylinder 103 through the circulation inlet pipe 104, pressurizes it, and then merges it into the inlet pipe 101 via the circulation outlet pipe 106. Simultaneously, the return water from the anaerobic ammonia oxidation module 3 is pressurized via the outlet return pipe 308 and the booster pump 317, and then merges into the inlet pipe 101 via the return water inlet pipe 318.
[0053] A gap of 500-1000 mm is provided between the upper part of the guide tube 103 and the denitrification three-phase separator 107. The water effluent from the guide tube 103 can be turned out through this gap, and part of the effluent flows downward to fill the space at the bottom where the wastewater drawn into the guide tube 103 flows away, forming a flow pattern that flows up and down along the inside and outside of the guide tube 103. This allows the denitrifying biological sludge and wastewater in the denitrification cylinder 100 to be fully mixed and reacted. At this time, the nitrate nitrogen in the return water is reduced to nitrogen gas by the denitrifying bacteria through the use of easily biodegradable organic matter in the wastewater as a carbon source, while removing most of the organic matter in the incoming water. Under the action of the denitrification three-phase separator 107, the gas, liquid, and solid phases in the denitrification cylinder 100 are separated into three phases: the nitrogen gas produced by denitrification is discharged into the atmosphere through the denitrification exhaust pipe 110; the denitrification effluent is collected through the denitrification water collection pipe 108 and then enters the aeration phosphorus removal module 2 through the denitrification effluent pipe 109; the denitrification sludge is returned to the denitrification cylinder 100 under the action of gravity to continue the reaction; in addition, due to the increase of denitrifying bacteria during the denitrification process... To maintain the concentration of biological sludge in the denitrification zone, excess biological sludge is discharged through the denitrification sludge discharge pipe 111 at the bottom of the denitrification cylinder 100. Considering the alkalinity generated during the denitrification process, an online denitrification pH meter 113 is installed in the middle of the denitrification cylinder 100 to monitor the pH of the mixed liquor in the denitrification cylinder 100 in real time. When the pH is high, acid is added through the denitrification dosing pipe 112 to adjust the pH range to 6.5-7.5.
[0054] The effluent from the denitrification zone outlet pipe 109 enters the bottom of the aeration and phosphorus removal cylinder 200 through the aeration and phosphorus removal water distribution pipe 201. Air enters the bottom of the aeration and phosphorus removal cylinder 200 through the aeration and phosphorus removal air pipe 202 and is evenly distributed into the water via the aeration and phosphorus removal aerator 203. This provides dissolved oxygen to the activated sludge inside the aeration and phosphorus removal cylinder 200, allowing residual organic matter in the influent to be degraded by heterotrophic bacteria, thus ensuring the effluent meets the COD requirements of the anaerobic ammonia oxidation reaction. The aeration and phosphorus removal aerator 203 is a coarse-pore aerator, which avoids excessively high dissolved oxygen levels while ensuring sufficient mixing energy. The aeration and phosphorus removal guide cylinder 204 is located above the aeration and phosphorus removal aerator 203. After aeration, the medium density inside the guide cylinder is lower than that outside, forming a high-speed circulation, providing high mixing energy, and promoting the formation of magnesium ammonium phosphate (struvite). Water, air, and sludge in the aeration phosphorus removal cylinder 200 flow upwards into the aeration phosphorus removal three-phase separator 205 for three-phase separation. Excess air escapes along the water surface. The effluent from the aeration phosphorus removal cylinder 200 is discharged to the anaerobic ammonia oxidation module 3 through the aeration phosphorus removal effluent pipe 206. The sludge in the aeration phosphorus removal cylinder 200 falls to the bottom of the aeration phosphorus removal three-phase separator 204 under gravity and falls back into the aeration phosphorus removal cylinder 200 to continue participating in the reaction. Considering that microorganisms will proliferate during the COD degradation process, forming mixed sludge with struvite crystals, it is finally discharged through the aeration phosphorus removal sludge discharge pipe 208. Dissolved oxygen is an important control parameter of the aeration phosphorus removal module. The dissolved oxygen concentration in the aeration phosphorus removal cylinder 200 is monitored in real time by the online DO meter 207 and the air volume in the aeration phosphorus removal air pipe 202 is controlled accordingly, so that the dissolved oxygen in the aeration phosphorus removal cylinder 200 is controlled at 0.3-0.5 mg / L.
[0055] The effluent from the aeration and phosphorus removal outlet pipe 206 enters the anammox cylinder 300 via the anammox water distribution pipe 301, while air enters the bottom of the anammox cylinder 300 through the anammox air pipe 302 and is evenly distributed into the water via the anammox aerator 303. This provides oxygen for the nitrification of ammonia nitrogen in the anammox granular sludge within the anammox cylinder 300 and simultaneously mixes the wastewater and granular sludge. Under the action of anammox bacteria, ammonia nitrogen in the wastewater is ultimately converted into nitrogen gas, while a portion of nitrate nitrogen is generated. Inside the anammox cylinder 300, water, air, and sludge flow upwards together and undergo three-phase separation under the action of the anammox three-phase separator 304. The gas escapes from the water surface, while the anammox granular sludge flows back into the anammox cylinder to continue participating in the reaction. The effluent is discharged into the collection cylinder 306 through the anammox water pipe 305. The function of the water collection cylinder 306 is to provide a certain buffer space for the water outlet and further remove gas from the water to prevent cavitation of the subsequent booster pump 317. The bottom of the water collection cylinder 306 is connected to the water outlet return pipe 308, and the top overflows to allow the final water outlet to be discharged outside the system through the water pipe 307.
[0056] Considering that anaerobic ammonia oxidizing bacteria have high activity at temperatures between 30 and 40°C, and low activity below 35°C, the water temperature in the anaerobic ammonia oxidizing cylinder 300 needs to be controlled by heating when the water temperature is low. The water temperature inside the cylinder 300 is monitored in real time by an online anaerobic ammonia oxidizing thermometer 314, and the external heating system is controlled accordingly to maintain the water temperature between 33 and 38°C. During heating, hot water flows from the hot water inlet pipe 309 to the heat exchange pipe 310. After heat exchange, the water temperature decreases, and then it flows back to the external heating system through the hot water return pipe 311.
[0057] Furthermore, since this technical solution employs a one-stage anaerobic ammonia oxidation process, which includes nitrification, alkalinity is consumed. The pH of the mixed solution within the anaerobic ammonia oxidation cylinder 300 is monitored in real-time using an online pH meter 315, and the addition of alkali solution via the dosing pipe 312 is controlled to maintain the pH between 7.5 and 8.0. The trace elements required by the anaerobic ammonia oxidation microorganisms are added to the anaerobic ammonia oxidation cylinder 300 via the trace element dosing pipe 313. For the one-stage anaerobic ammonia oxidation reaction, dissolved oxygen is a crucial control parameter. The dissolved oxygen in the mixed solution within the cylinder 300 is monitored in real-time using an online DO meter 316, and the air volume in the air pipe 302 is adjusted to maintain the dissolved oxygen below 0.3 mg / L.
[0058] In this embodiment, the organic matter carried in the incoming water is used as a carbon source for denitrification of nitrate nitrogen in the anammox effluent, eliminating the need for an additional carbon source. Unused organic matter in the denitrified effluent is further removed by high-load aeration in the subsequent phosphorus removal module, significantly reducing the power consumption compared to direct high-load aeration of the incoming water. Simultaneously, by adding magnesium hydroxide to the phosphorus removal module, phosphorus is removed using the struvite crystallization principle. This causes phosphate and ammonium ions in the water to react with magnesium to form magnesium ammonium phosphate (struvite), solving the phosphate problem in the incoming water and reducing the influent ammonia nitrogen load for the subsequent anammox module. This improves the stability of the microbial system within the subsequent anammox module, achieving low-energy, high-efficiency biological denitrification and ensuring that the final effluent meets total nitrogen discharge requirements without the need for further deep denitrification. The elimination of subsequent denitrification in the effluent reduces the complexity of subsequent treatment for applications with high total nitrogen discharge requirements. Furthermore, the generated struvite precipitate can be extracted and processed for sale as a slow-release fertilizer, possessing economic value and enabling resource recycling.
[0059] The technical solution in this embodiment achieves integrated phosphorus and nitrogen removal, significantly shortening the process flow, thereby reducing the footprint and saving investment. For wastewater with low C / N ratio, high ammonia, and phosphate content, compared to existing systems combining high-load aeration and anaerobic ammonium oxidation, as well as combined systems of denitrification-nitrification and anaerobic ammonium oxidation, it greatly reduces operating costs and achieves one-stop, low-energy, high-efficiency, and deep phosphorus and nitrogen removal. Taking an influent ammonia nitrogen of 1000 mg / L and phosphate of 200 mg / L as an example: the total nitrogen removal rate increases from 81.6% to 96%, operating costs decrease by 1.10 yuan / cubic meter of wastewater, electricity consumption decreases by 20%, and phosphorus removal operating costs are only 0.3 yuan / cubic meter of wastewater.
[0060] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the protection scope of the present invention.
Claims
1. An integrated phosphorus and nitrogen removal device, characterized in that: The system includes a denitrification module, an aeration phosphorus removal module, and an anaerobic ammonia oxidation module. The aeration phosphorus removal module and the anaerobic ammonia oxidation module are located above the denitrification module, with the aeration phosphorus removal module located outside the anaerobic ammonia oxidation module. The denitrification module has an inlet pipe, and the anaerobic ammonia oxidation module has an outlet pipe. The denitrification module is connected to the aeration phosphorus removal module through the denitrification outlet pipe, and the aeration phosphorus removal module is connected to the anaerobic ammonia oxidation module through the aeration phosphorus removal outlet pipe. The anaerobic ammonia oxidation module is connected to the denitrification module through a return water inlet pipe. The aeration phosphorus removal module is equipped with a magnesium hydroxide dosing pipe for adding magnesium hydroxide to remove phosphorus.
2. The integrated phosphorus and nitrogen removal device according to claim 1, characterized in that: The denitrification module includes a denitrification cylinder, which contains, from bottom to top, a denitrification water distributor, a flow guide cylinder, a denitrification three-phase separator, and a denitrification water collection pipe. An inlet pipe and a circulating water pipe are connected to the bottom two sides of the denitrification cylinder, respectively. The circulating water pipe is connected to the inlet pipe via a circulating pump. The inlet pipe is connected to the denitrification water distributor. The top of the denitrification cylinder is connected to a denitrification exhaust pipe and a denitrification water outlet pipe; The lower middle part of the denitrification cylinder is connected to a denitrification dosing pipe, which extends into the denitrification cylinder and is connected to the guide cylinder; the middle part of the denitrification cylinder is equipped with an online denitrification pH meter; the bottom of the denitrification cylinder is equipped with a denitrification sludge discharge pipe.
3. The integrated phosphorus and nitrogen removal device according to claim 2, characterized in that: The denitrification water distributor is equipped with several vertically upward nozzles, and the nozzles are located inside the bottom of the guide tube; the distance between the denitrification three-phase separator and the guide tube is 500-1000mm.
4. The integrated phosphorus and nitrogen removal device according to claim 2, characterized in that: The aeration phosphorus removal module includes an aeration phosphorus removal cylinder. The bottom of the cylinder is equipped with an aeration phosphorus removal water distribution pipe connected to the denitrification effluent pipe. An aeration phosphorus removal aerator is installed inside the cylinder, positioned above the water distribution pipe and connected to an air aerator. Above the aerator is an aeration phosphorus removal flow guide cylinder, and above the flow guide cylinder is an aeration phosphorus removal three-phase separator. A magnesium hydroxide dosing pipe enters the flow guide cylinder. The inlet of the effluent pipe is located at the top of the three-phase separator.
5. The integrated phosphorus and nitrogen removal device according to claim 4, characterized in that: The aeration phosphorus removal module includes an online phosphorus removal DO instrument and an aeration phosphorus removal sludge discharge pipe. The online phosphorus removal DO instrument is inserted below the liquid level inside the aeration phosphorus removal cylinder. The aeration phosphorus removal sludge discharge pipe is connected to the aeration phosphorus removal cylinder. The aeration phosphorus removal aerator is a coarse-pore aerator.
6. The integrated phosphorus and nitrogen removal device according to claim 5, characterized in that: The anaerobic ammonia oxidation module includes an anaerobic ammonia oxidation cylinder and a water collection cylinder. An anaerobic ammonia oxidation water distribution pipe is provided at the bottom of the anaerobic ammonia oxidation cylinder, and the anaerobic ammonia oxidation water distribution pipe is connected to the aeration and phosphorus removal effluent pipe. An anaerobic ammonia oxidation aerator is provided above the anaerobic ammonia oxidation water distribution pipe, and the anaerobic ammonia oxidation aerator is connected to the anaerobic ammonia oxidation air pipe. An anaerobic ammonia oxidation three-phase separator is provided in the upper middle part of the anaerobic ammonia oxidation cylinder. The top of the anaerobic ammonia oxidation three-phase separator is equipped with an anaerobic ammonia oxidation outlet pipe, which is connected to a water collection cylinder. The upper part of the water collection cylinder is connected to the outlet pipe. The bottom of the water collection cylinder is connected to the return water inlet pipe through an outlet return pipe. The anaerobic ammonia oxidation cylinder is equipped with a heat exchange tube, the two ends of which are connected to a hot water inlet pipe and a hot water return pipe, respectively. The upper part of the anaerobic ammonia oxidation cylinder is equipped with an anaerobic ammonia oxidation pH dosing pipe and a trace element dosing pipe.
7. The integrated phosphorus and nitrogen removal device according to claim 6, characterized in that: The anaerobic ammonia oxidation module includes an online anaerobic ammonia oxidation thermometer, an online anaerobic ammonia oxidation pH meter, and an online anaerobic ammonia oxidation DO meter. These devices are inserted below the liquid level inside the anaerobic ammonia oxidation cylinder. A booster pump is installed between the effluent return pipe and the return water inlet pipe. The bottom of the water collection cylinder is inverted conical. The anaerobic ammonia oxidation aerator is a microporous aerator.
8. The integrated phosphorus and nitrogen removal device according to claim 7, characterized in that: The diameter of the denitrification cylinder is the same as that of the anaerobic ammonia oxidation cylinder, but smaller than the outer diameter of the aeration phosphorus removal cylinder. The bottom of the aeration phosphorus removal cylinder is an inverted cone shape.
9. The integrated phosphorus and nitrogen removal device according to claim 7 or 8, characterized in that: It includes a control module. The outlet of the denitrification dosing pipe is connected to the denitrification dosing control valve. The aeration and phosphorus removal air pipe is connected to the aeration and phosphorus removal air control valve. The hot water inlet pipe is connected to a hot water valve or the inlet end of the hot water inlet pipe is equipped with a heating thermostat. The outlet of the anammox pH dosing pipe is connected to the anammox pH dosing control valve. The control module is electrically connected to the online denitrification pH meter, the online aeration and phosphorus removal DO meter, the online anammox thermometer, the online anammox pH meter, the online anammox DO meter, the denitrification dosing control valve, the aeration and phosphorus removal air control valve, the hot water valve or the heating thermostat, and the anammox pH dosing control valve.