Wastewater treatment system

Abstract

The invention discloses a wastewater treatment system, and relates to the technical field of urea wastewater treatment.The wastewater treatment system comprises a liquid inlet tank, a reaction tank, a plurality of agent boxes, a centrifugal machine, a first ion detection unit and a controller, the reaction tank is connected with the liquid inlet tank through a first connecting pipe, and the agent boxes are connected with the reaction tank through agent injection pipes; the chemical injection pipe is provided with a first valve, the centrifugal machine is connected with the reaction tank through a pipeline, the first ion detection unit is arranged on the first connecting pipe and electrically connected with the controller, and the first ion detection unit is used for detecting the concentration of ammonium ions and transmitting the detected value to the controller. The controller is electrically connected with the first valve and used for adjusting the first valve according to the measured ammonium ion concentration value so as to control the flow of the corresponding medicine injection pipe. According to the wastewater treatment system, the ion concentration is monitored in real time so as to control the injection flow of the medicament, the reaction ratio is accurately controlled, the removal efficiency of ammonia nitrogen in wastewater is improved, and wastewater discharge reaches the standard.

Description

Technical Field

[0001] This invention relates to the field of urea wastewater treatment technology, and more specifically, to a wastewater treatment system. Background Technology

[0002] Urea wastewater is a body of water formed by the absorption of ammonia gas from emergency discharges from the urea hydrolysis reactor, mixed with wastewater generated during the maintenance of equipment such as the urea hydrolysis reactor, urea dissolving tank, and urea solution storage tank. Its components include ammonia nitrogen, residual urea, salt, and trace amounts of heavy metals. According to environmental regulations, the ammonia nitrogen content in wastewater discharge must be below 40 mg / L. Ammonia nitrogen in urea wastewater is a key indicator affecting whether the wastewater meets this discharge requirement. Failure to treat the ammonia nitrogen in urea wastewater can easily lead to excessive ammonia nitrogen levels, increasing environmental compliance risks and posing potential operational hazards to the equipment.

[0003] In related technologies, the urea wastewater treatment process has the following problems: it is impossible to timely grasp the changes in the concentration of ammonia nitrogen and ions required for the reaction in the wastewater, the dosage is difficult to control precisely, abnormal ammonia nitrogen index cannot be detected in time, and there are problems such as low ammonia nitrogen removal efficiency, high system operating costs, and difficulty in achieving the goals of wastewater discharge meeting standards and resource recycling. Summary of the Invention

[0004] The present invention aims to at least partially solve one of the technical problems in the related art.

[0005] Therefore, this invention proposes a wastewater treatment system that improves the removal efficiency of ammonia nitrogen in wastewater by controlling the reaction ratio through real-time monitoring of ion concentration, and ensures that the wastewater discharge meets the standards.

[0006] The wastewater treatment system of this invention includes: An inlet tank, used for temporary storage of wastewater; A reaction vessel is connected to the liquid inlet tank via a first connecting pipe, and a first pump for pumping liquid is provided on the first connecting pipe. A stirring rod is rotatably installed inside the reaction vessel. A reagent tank, wherein multiple reagent tanks are provided and connected to the reaction vessel via injection pipes, and a first valve is provided on the injection pipes for controlling the flow rate of the injection pipes; A centrifuge is connected to the reaction vessel via a pipe. The centrifuge is used to centrifuge the mixture discharged from the reaction vessel. The centrifuge is equipped with a solid phase drain pipe and a liquid phase drain pipe. A first ion detection unit and a controller are provided. The first ion detection unit is located in the first connecting tube and electrically connected to the controller. The first ion detection unit is used to detect the concentration of ammonium ions and transmit the measured value to the controller. The controller is electrically connected to the first valve and is used to adjust the first valve according to the measured concentration of ammonium ions to control the flow rate of the corresponding injection tube.

[0007] The wastewater treatment system of this invention controls the injection flow rate of the reagent by real-time monitoring of ion concentration, accurately controls the reaction ratio, improves the removal efficiency of ammonia nitrogen in wastewater, and ensures that wastewater discharge meets the standards.

[0008] In some embodiments, the liquid phase manifold is equipped with a three-way valve. One outlet of the three-way valve is connected to a drain pipe, and the other outlet of the three-way valve is connected to a return pipe. The other end of the return pipe is connected to the inlet tank. A third pump is provided on the return pipe. The liquid phase manifold or the centrifuge is equipped with an ion concentration detector electrically connected to the controller and used to detect the concentration of ammonium ions. The controller is used to control the three-way valve to connect the drain pipe and the liquid phase manifold when the value measured by the ion concentration detector is less than a set value, and to control the three-way valve to connect the drain pipe and the return pipe when the value measured by the ion concentration detector is not less than the set value.

[0009] In some embodiments, there are two reagent tanks, one of which stores a magnesium source, which is a leachate from power plant ash residue, and the other of which stores a phosphorus source, which is desulfurization wastewater.

[0010] In some embodiments, a second ion detection unit and a third ion detection unit are further included. The second ion detection unit and the third ion detection unit are respectively disposed on the first connecting tube and electrically connected to the controller. The second ion detection unit is used to detect the magnesium ion concentration and transmit the measured value to the controller. The third ion detection unit is used to detect the phosphate ion concentration and transmit the measured value to the controller. The controller is used to adjust the corresponding first valve according to the measured magnesium ion concentration or phosphate ion concentration value to control the flow rate of the corresponding drug injection tube.

[0011] In some embodiments, a fourth ion detection unit is also included, which is disposed in the first connecting tube and used to detect calcium ion concentration.

[0012] In some embodiments, a pH sensor electrically connected to the controller is also included, the pH sensor being disposed within the reaction vessel and located in the solution, the pH sensor being used to measure the acidity or alkalinity of the solution within the reaction vessel.

[0013] In some embodiments, the controller is provided with a touch screen display for displaying the ammonium ion concentration and the pH of the solution in the reaction vessel, and / or the controller is electrically connected to an alarm for controlling the alarm to issue an alarm signal when the pH of the solution in the reaction vessel exceeds a set range.

[0014] In some embodiments, an electrically connected ultrasonic generator and an ultrasonic probe are also included, the ultrasonic probe being disposed within the reaction vessel and located within the solution, the ultrasonic probe being used to apply pulsed ultrasonic waves to the solution.

[0015] In some embodiments, the system further includes a settling tank connected to the reaction vessel via a second connecting pipe, the second connecting pipe being equipped with a second pump; the settling tank connected to the centrifuge via a third connecting pipe, the third connecting pipe being equipped with a third valve; the settling tank being equipped with a discharge pipe for discharging particulate crystals, the discharge pipe being equipped with a fourth valve.

[0016] In some embodiments, the inlet tank is provided with an inlet pipe, and a filter screen is provided inside the inlet tank corresponding to the inlet pipe. The filter screen is used to filter impurities in the wastewater discharged from the inlet pipe. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a wastewater treatment system according to an embodiment of the present invention.

[0018] Figure 2 This is a schematic diagram of the structure of the inlet tank in the wastewater treatment system of this invention.

[0019] Figure 3 This is a schematic diagram of the structure of the reaction tank in the wastewater treatment system of this invention.

[0020] Figure 4 This is a schematic diagram of the centrifuge connection in the wastewater treatment system of this invention.

[0021] Figure label: 1. Liquid inlet tank; 2. Reaction vessel; 3. Reagent tank; 4. Centrifuge; 5. First ion detection unit; 6. Controller; 7. First connecting pipe; 8. First pump; 9. Stirring rod; 10. Injection pipe; 11. First valve; 12. Solid phase manifold; 13. Liquid phase manifold; 14. Three-way valve; 15. Drain pipe; 16. Return pipe; 17. Third pump; 18. Second ion detection unit; 19. Third ion detection unit; 20. Fourth ion detection unit; 21. pH sensor; 22. Alarm; 23. Ultrasonic generator; 24. Ultrasonic probe; 25. Settling tank; 26. Second connecting pipe; 27. Second pump; 28. Third connecting pipe; 29. ​​Discharge pipe; 30. Liquid inlet pipe; 31. Filter screen. Detailed Implementation

[0022] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0023] like Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, the wastewater treatment system of this embodiment includes an inlet tank 1, a reaction tank 2, a reagent tank 3, a centrifuge 4, a first ion detection unit 5, and a controller 6. The inlet tank 1 is used to temporarily store wastewater. The reaction tank 2 is connected to the inlet tank 1 through a first connecting pipe 7, and a first pump 8 for pumping liquid is provided on the first connecting pipe 7. A stirring rod 9 is rotatably provided inside the reaction tank 2. The reagent tank 3 has multiple units and is connected to the reaction tank 2 through a dosing pipe 10. A first valve 11 for controlling the flow rate of the dosing pipe 10 is provided on the dosing pipe 10. The centrifuge 4 is connected to the reaction tank 2 through a pipe. The centrifuge 4 is used to centrifuge the mixed liquid discharged from the reaction tank 2. The centrifuge 4 has a solid phase discharge pipe 12 and a liquid phase discharge pipe 13. The first ion detection unit 5 is located on the first connecting pipe 7 and is electrically connected to the controller 6. The first ion detection unit 5 is used to detect the concentration of ammonium ions and transmit the measured value to the controller 6. The controller 6 is electrically connected to the first valve 11 and is used to adjust the first valve 11 according to the measured ammonium ion concentration value to control the flow rate of the corresponding dosing pipe 10.

[0024] The working principle of the wastewater treatment system in this embodiment of the invention is as follows: The inlet tank 1 serves as a pretreatment carrier, providing temporary storage and initial buffer space for urea wastewater. The wastewater in the inlet tank 1 is transported to the reaction tank 2 through the first connecting pipe 7 and the first pump 8, avoiding the impact of flow fluctuations on the reaction tank 2 when the wastewater directly enters the reaction tank 2, ensuring that the reaction in the reaction tank 2 proceeds under stable conditions. The ammonium ion concentration of the wastewater transported in the first connecting pipe 7 is monitored by the first ion detection unit 5. The controller 6 controls the flow rate of the reagent entering the reaction tank 2 through the first valve 11, increasing the number of ammonium ions participating in the reaction and the sufficiency of the reaction. The stirring rod 9 in the reaction tank 2 rotates, improving the mixing efficiency of wastewater and reagent, and further increasing the reaction rate. The mixed liquid discharged from the reaction tank 2 is centrifuged in the centrifuge 4 to obtain struvite crystals and solution, improving the ammonia nitrogen removal efficiency in the wastewater.

[0025] The wastewater treatment system of this invention monitors the concentration of ammonium ions in real time, which makes it easy to control the amount of ammonium ions to be removed. This, in turn, allows the controller 6 to control the injection flow rate of the reagent, accurately control the reaction ratio, improve the removal efficiency of ammonia nitrogen in wastewater, and facilitate wastewater discharge to meet standards.

[0026] Optionally, the first ion detection unit 5 is an ammonium ion detector.

[0027] Optionally, a servo motor is fixedly installed on the reaction vessel 2, and the stirring rod 9 is fixedly installed at the output end of the servo motor. The servo motor drives the stirring rod 9 to rotate at a specific speed. The speed design needs to take into account both mixing efficiency and crystal integrity, to avoid insufficient mixing due to excessively low speed, which would reduce the probability of ion collision and slow down the reaction rate; at the same time, to avoid excessive shear force due to excessively high speed, which would break the initially formed struvite microcrystals and affect the final crystallization particle size and purity.

[0028] Optionally, the environment inside the reaction vessel 2 should meet the thermodynamic conditions for struvite formation, such as a temperature of 25-35°C, to promote the forward chemical reaction.

[0029] Optionally, the centrifuge 4 is equipped with a drive motor, the output end of which is fixedly connected to a drum located inside the centrifuge 4. The drive motor drives the drum to rotate at a speed of 2400-2600 r / min, generating a centrifugal force with a separation factor of 1000-1100. This force throws the denser solid struvite in the mixture onto the inner wall of the centrifuge 4, while the liquid phase flows through the sieve holes on the drum wall to the liquid phase discharge pipe 13, achieving efficient solid-liquid separation. The solid struvite is discharged from the solid phase discharge pipe 12 and dried in an external dryer until the moisture content is ≤3.8-4.0%. Excessive moisture content will cause struvite to clump, affecting subsequent resource utilization. For example, in the use of agricultural slow-release fertilizer, controlling the moisture content can ensure that the particles are loose and do not damage the crystal structure, ultimately obtaining high-purity struvite.

[0030] In some embodiments, such as Figure 1 and Figure 4 As shown, the liquid phase manifold 13 is equipped with a three-way valve 14. One outlet of the three-way valve 14 is connected to a drain pipe 2915, and the other outlet of the three-way valve 14 is connected to a return pipe 16. The other end of the return pipe 16 is connected to the inlet tank 1. A third pump 17 is provided on the return pipe 16. The liquid phase manifold 13 or the centrifuge 4 is equipped with an ion concentration detector that is electrically connected to the controller 6 and is used to detect the concentration of ammonium ions. The controller 6 is used to control the three-way valve 14 to connect the drain pipe 2915 and the liquid phase manifold 13 when the value measured by the ion concentration detector is less than the set value, and to control the three-way valve 14 to connect the drain pipe 2915 and the return pipe 16 when the value measured by the ion concentration detector is not less than the set value.

[0031] Specifically, a three-way valve 14 is installed, forming a first discharge branch and a second discharge branch at the return pipe 16 of the centrifuge 4. The first discharge branch includes a drain pipe 2915 connected to the three-way valve 14, which is used to discharge wastewater with ammonia nitrogen content that meets the standards. The second discharge branch includes a return pipe 16 connected to the three-way valve 14, which is used to transport wastewater with ammonia nitrogen content that does not meet the standards to the inlet tank 1, further removing ammonium ions from the wastewater. If the ammonium ion concentration measured by the ion concentration detector is not less than 14 mg / L, it indicates that the standard is not met, and the second discharge branch is activated to re-treat the wastewater. If the ammonium ion concentration measured by the ion concentration detector is less than 14 mg / L, it indicates that the standard is met, and the first discharge branch is activated to directly discharge the wastewater. Through the coordinated operation of the ion concentration detector, the three-way valve 14, and the ion concentration detector, the solution after the reaction in the centrifuge 4 is further monitored to ensure that the discharged wastewater meets the discharge standards.

[0032] In some embodiments, such as Figure 1 and Figure 3 As shown, there are two reagent tanks 3. One reagent tank 3 stores a magnesium source, which is a leachate from power plant ash residue. The other reagent tank 3 stores a phosphorus source, which is desulfurization wastewater.

[0033] Specifically, by utilizing the effective components in industrial by-products, such as the abundant magnesium ions in the leachate of power plant ash residue and the free phosphate ions in desulfurization wastewater, traditional high-purity magnesium and phosphate salts, such as MgCl2 and Na3PO4, can be replaced. This not only reduces the cost of reagent procurement but also realizes the resource utilization of industrial waste, which is in line with the logic of the circular economy.

[0034] In some embodiments, such as Figure 1 and Figure 3 As shown, it also includes a second ion detection unit 18 and a third ion detection unit 19. The second ion detection unit 18 and the third ion detection unit 19 are respectively disposed on the first connecting pipe 7 and electrically connected to the controller 6. The second ion detection unit 18 is used to detect the magnesium ion concentration and transmit the measured value to the controller 6. The third ion detection unit 19 is used to detect the phosphate ion concentration and transmit the measured value to the controller 6. The controller 6 is used to adjust the corresponding first valve 11 according to the measured magnesium ion concentration or phosphate ion concentration value to control the flow rate of the corresponding drug injection pipe 10.

[0035] Based on the precise measurement of magnesium ion concentration and phosphate ion concentration by the second ion detection unit 18 and the third ion detection unit 19, the injection tube 10 and the first valve 11 precisely control the amount of reagent injected, injecting magnesium source and phosphorus source according to the ion reaction ratio of 1:1:1 to increase the reaction amount of ammonium ions. The opening degree of the first valve 11 can be dynamically adjusted according to the subsequent ion monitoring data to improve the stability of the reagent ratio and the completeness of the reaction.

[0036] Preferably, the total amount of magnesium ions should be 110% of the total amount of ammonium ions. Excess magnesium ions can promote the chemical equilibrium to shift towards the formation of struvite, and avoid the residue of ammonium ions due to incomplete reaction.

[0037] Optionally, the second ion detection unit 18 is a magnesium ion detector.

[0038] Optionally, the third ion detection unit 19 is a phosphate ion detector.

[0039] In some embodiments, such as Figure 1 and Figure 3 As shown, it also includes a fourth ion detection unit 20, which is located in the first connecting tube 7 and is used to detect calcium ion concentration.

[0040] Calcium ions are monitored to ensure that the concentration is less than 7 mg / L, thus preventing the formation of calcium phosphate precipitate from calcium ions and phosphate ions. Calcium phosphate is easily adsorbed on the surface of struvite, which affects its purity and consequently its recycling.

[0041] Optionally, the fourth ion detection unit 20 is a calcium ion detector.

[0042] In some embodiments, such as Figure 1 and Figure 3 As shown, it also includes a pH sensor 21 electrically connected to the controller 6. The pH sensor 21 is located inside the reaction vessel 2 in the solution and is used to measure the acidity or alkalinity of the solution in the reaction vessel 2.

[0043] pH directly affects the ionic form of struvite formation. Under acidic conditions, such as pH < 8.4, PO42- 3- Easily converted to HPO4 2- H2PO4 - It cannot effectively combine with magnesium ions to form struvite. Under excessively alkaline conditions, such as pH > 10.0, NH4+... + It will be converted into NH3 and volatilize, while Mg 2+ Mg(OH)2 precipitate will be generated, so the pH needs to be controlled in the optimal range of 8.4-9.0 to ensure that the ionic form is suitable for the reaction requirements.

[0044] By setting up a pH sensor 21, the acidity and alkalinity of the solution in the reaction vessel 2 can be monitored in real time. Based on the measurement results, the acidity and alkalinity of the solution in the reaction vessel 2 can be adjusted to promote the forward progress of the chemical reaction.

[0045] In some embodiments, the controller 6 is provided with a touch screen display for displaying the concentration of ammonium ions and the pH of the solution in the reaction vessel 2.

[0046] The touchscreen display facilitates system control and allows for intuitive observation of ion concentration, enabling personnel to easily monitor and control the system.

[0047] In some embodiments, such as Figure 1 As shown, the controller 6 is electrically connected to the alarm 22. The controller 6 is used to control the alarm 22 to issue an alarm signal when the pH of the solution in the reaction vessel 2 exceeds the set range.

[0048] Specifically, the controller 6 stores preset values, such as 7.2≤pH≤9.8. When the pH of the solution in the reaction tank 2 exceeds this range, the controller 6 controls the alarm 22 to issue an alarm signal so that personnel can adjust the pH of the solution in a timely manner.

[0049] In some embodiments, such as Figure 1 and Figure 3 As shown, it also includes an ultrasonic generator 23 and an ultrasonic probe 24 that are electrically connected. The ultrasonic probe 24 is located inside the reaction vessel 2 and in the solution. The ultrasonic probe 24 is used to apply pulsed ultrasonic waves to the solution.

[0050] Specifically, the ultrasonic reactor generates pulsed ultrasonic waves with a frequency of 26-28kHz and a power of 240-260W, which are transmitted to the mixture in the reaction vessel 2 through the ultrasonic probe 24. A large number of microbubbles are generated in the mixture. When the microbubbles burst rapidly, they release local high temperature and high pressure. On the one hand, this breaks the local concentration gradient of magnesium ions, phosphate ions and ammonium ions, accelerates ion diffusion and collision frequency, and increases the reaction rate. On the other hand, the shock wave generated by the bursting of microbubbles can destroy the disordered agglomeration structure of struvite microcrystals, reduce the surface energy of the microcrystals, and promote their directional growth along specific crystal planes to form crystals with larger particle size and higher purity, thus avoiding the adsorption of impurities by small microcrystals and the resulting decrease in purity.

[0051] In some embodiments, such as Figure 1 and Figure 4 As shown, it also includes a settling tank 25, which is connected to the reaction tank 2 via a second connecting pipe 26. A second pump 27 is installed on the second connecting pipe 26. The settling tank 25 is connected to the centrifuge 4 via a third connecting pipe 28. A third valve is installed on the third connecting pipe 28. The settling tank 25 is equipped with a discharge pipe for discharging granular crystals, and a fourth valve is installed on the discharge pipe.

[0052] The mixture discharged from reaction tank 2 undergoes preliminary separation in settling tank 25 based on the law of gravity settling. Due to the density difference between the struvite crystals and the liquid phase, struvite crystals with a particle size ≥38-40 micrometers will settle to the bottom of the tank under static conditions. This process can remove most of the coarse crystal particles. The settled crystal particles are discharged through the discharge pipe, and the settled liquid is discharged through the second connecting pipe 26, reducing the separation load of the subsequent centrifuge 4, preventing fine microcrystals from clogging the sieve holes of the centrifuge 4, and reducing the energy consumption of the centrifuge 4.

[0053] In some embodiments, such as Figure 1 As shown, the liquid inlet tank 1 is provided with a liquid inlet pipe 30, and a filter screen 31 is provided inside the liquid inlet tank 1 corresponding to the liquid inlet pipe 30. The filter screen 31 is used to filter impurities in the wastewater discharged from the liquid inlet pipe 30.

[0054] Specifically, the filter screen 31 is set at the top of the liquid inlet tank 1. By setting the filter screen 31, solid impurities in the wastewater, such as pipe corrosion residue and urea crystals, are intercepted and removed, thereby improving the stability of the mixing flow field in the reaction tank 2 and preventing impurities from clogging the delivery pipes or adhering to the inner wall of the reaction tank 2, which would disrupt the uniformity of solid-liquid mixing and improve the stability of the reaction in the reaction tank 2.

[0055] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0056] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0057] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0058] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0059] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0060] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A wastewater treatment system, characterized in that, include: An inlet tank, used for temporary storage of wastewater; A reaction vessel is connected to the liquid inlet tank via a first connecting pipe, and a first pump for pumping liquid is provided on the first connecting pipe. A stirring rod is rotatably installed inside the reaction vessel. A reagent tank, wherein multiple reagent tanks are provided and connected to the reaction vessel via injection pipes, and a first valve is provided on the injection pipes for controlling the flow rate of the injection pipes; A centrifuge is connected to the reaction vessel via a pipe. The centrifuge is used to centrifuge the mixture discharged from the reaction vessel. The centrifuge is equipped with a solid phase drain pipe and a liquid phase drain pipe. A first ion detection unit and a controller are provided. The first ion detection unit is located in the first connecting tube and electrically connected to the controller. The first ion detection unit is used to detect the concentration of ammonium ions and transmit the measured value to the controller. The controller is electrically connected to the first valve and is used to adjust the first valve according to the measured concentration of ammonium ions to control the flow rate of the corresponding injection tube.

2. The wastewater treatment system according to claim 1, characterized in that, The liquid phase manifold is equipped with a three-way valve. One outlet of the three-way valve is connected to a drain pipe, and the other outlet of the three-way valve is connected to a return pipe. The other end of the return pipe is connected to the inlet tank. A third pump is installed on the return pipe. The liquid phase manifold or the centrifuge is equipped with an ion concentration detector electrically connected to the controller and used to detect the concentration of ammonium ions. The controller is used to control the three-way valve to connect the drain pipe and the liquid phase manifold when the value measured by the ion concentration detector is less than a set value, and to control the three-way valve to connect the drain pipe and the return pipe when the value measured by the ion concentration detector is not less than the set value.

3. The wastewater treatment system according to claim 1, characterized in that, The reagent tank is provided in two parts. One of the reagent tanks stores a magnesium source, which is a leachate solution from power plant ash residue. The other reagent tank stores a phosphorus source, which is desulfurization wastewater.

4. The wastewater treatment system according to claim 3, characterized in that, It also includes a second ion detection unit and a third ion detection unit. The second ion detection unit and the third ion detection unit are respectively disposed in the first connecting tube and electrically connected to the controller. The second ion detection unit is used to detect the magnesium ion concentration and transmit the measured value to the controller. The third ion detection unit is used to detect the phosphate ion concentration and transmit the measured value to the controller. The controller is used to adjust the corresponding first valve according to the measured magnesium ion concentration or phosphate ion concentration value to control the flow rate of the corresponding drug injection tube.

5. The wastewater treatment system according to claim 1, characterized in that, It also includes a fourth ion detection unit, which is located in the first connecting tube and is used to detect calcium ion concentration.

6. The wastewater treatment system according to claim 1, characterized in that, It also includes a pH sensor electrically connected to the controller, the pH sensor being located inside the reaction vessel within the solution, the pH sensor being used to measure the acidity or alkalinity of the solution inside the reaction vessel.

7. The wastewater treatment system according to claim 6, characterized in that, The controller is equipped with a touch screen display, which is used to display the ammonium ion concentration and the pH of the solution in the reaction vessel, and / or the controller is electrically connected to an alarm, which is used to control the alarm to issue an alarm signal when the pH of the solution in the reaction vessel exceeds a set range.

8. The wastewater treatment system according to any one of claims 1-7, characterized in that, It also includes an electrically connected ultrasonic generator and an ultrasonic probe, the ultrasonic probe being disposed inside the reaction vessel and located within the solution, the ultrasonic probe being used to apply pulsed ultrasonic waves to the solution.

9. The wastewater treatment system according to any one of claims 1-7, characterized in that, It also includes a settling tank, which is connected to the reaction vessel via a second connecting pipe and a second pump is installed on the second connecting pipe. The settling tank is connected to the centrifuge via a third connecting pipe and a third valve is installed on the third connecting pipe. The settling tank is equipped with a discharge pipe for discharging particulate crystals and a fourth valve is installed on the discharge pipe.

10. The wastewater treatment system according to any one of claims 1-7, characterized in that, The inlet tank is equipped with an inlet pipe, and a filter screen is provided inside the inlet tank corresponding to the inlet pipe. The filter screen is used to filter impurities in the wastewater discharged from the inlet pipe.

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