Limit removal device and removal method for inactive phosphorus in reclaimed water

Abstract

The invention discloses an ultimate removal device and removal method for inactive phosphorus in reclaimed water, and relates to the technical field of reclaimed water treatment.The ultimate removal device comprises a water inlet tank, a water outlet tank and a water outlet tank, the phosphorus removal filter tank is a metal tank body and comprises an aeration disc at the lower part and a metal phosphorus removal adsorbent at the upper part, and the aeration disc is connected with the water outlet of the water inlet tank; the ozone system is connected with the aeration disc; the produced water tank is communicated with the space, located above the metal phosphorus removal adsorbent, in the phosphorus removal filter tank, and a backwashing water opening of the produced water tank is connected with the phosphorus removal filter tank through a backwashing system; the on-line monitoring system is connected with the water inlet tank, the phosphorus removal filter tank and the water production tank; the automatic control system is in control connection with the valve on the water inlet tank, the self-cleaning filter, the ozone system and the backwashing system; according to the method, no additional phosphorus removal agent is used on the basis that the total phosphorus of the reclaimed water is less than or equal to 0.02 mg / L, and secondary pollution of metal ions to the water environment is avoided.

Description

Technical Field

[0001] The present invention belongs to the technical field of reclaimed water treatment, and more specifically, relates to a device and method for limiting removal of inactive phosphorus in reclaimed water. Background Art

[0002] The phosphorus content in reclaimed water has become a key factor affecting the safety of reclaimed water landscape reuse. In response to this problem, various regions have issued corresponding standards for the phosphorus content in reclaimed water based on the water quality of the receiving water bodies in the region. Among them, the Beijing Municipal Wastewater Treatment Plant Water Pollutant Discharge Standard (DB11 / 890-2012) A standard requires that the total phosphorus in the effluent be less than 0.2 mg / L, and the Kunming Municipal Wastewater Treatment Plant Main Water Pollutant Discharge Limit (DB5301 / T43-2020) A standard requires that the total phosphorus in the effluent be less than 0.05 mg / L. According to the U.S. Lake Nutrition Level Evaluation Standard (EPA standard), when the total phosphorus exceeds 0.02 mg / L, it reaches the eutrophication level of the water body and forms algal blooms. The current treatment process of the reclaimed water plant cannot reach this concentration, so it is necessary to develop a method for the extreme removal of phosphorus in reclaimed water to further reduce the phosphorus content entering the water environment.

[0003] The total phosphorus in the effluent of the reclaimed water plant mainly includes dissolved phosphorus and particulate phosphorus. Dissolved phosphorus accounts for about 90% (including orthophosphate, polyphosphate, metaphosphate, pyrophosphate, organic phosphorus, etc.), and particulate phosphorus accounts for about 10%. Among them, except for orthophosphate, other phosphorus components of dissolved phosphorus are called "inactive phosphorus", accounting for 30% to 50% of dissolved phosphorus. For inactive phosphorus, conventional chemical phosphorus removal and adsorption phosphorus removal methods have no obvious effect, and can only rely on advanced oxidation technology, but it can only oxidize inactive phosphorus into orthophosphate, and cannot be further removed. It only changes the phosphorus form, so an efficient treatment method is needed to remove the converted orthophosphate while oxidizing inactive phosphorus. Although chemical phosphorus removal agents can remove orthophosphate, there is a phosphorus removal limit. It can only ensure that the total phosphorus of reclaimed water is <0.1mg / L, and cannot reach the ultimate low phosphorus concentration (total phosphorus ≤0.02mg / L). There are also problems such as high carbon emissions, large agent consumption, and residual agents threatening ecological and environmental safety. Summary of the invention

[0004] The purpose of the present invention is to address the deficiencies in the prior art and to provide an extreme removal device and method for inactive phosphorus in reclaimed water. The removal device and method combine ozone advanced oxidation technology with metal material adsorption phosphorus removal technology, and achieve total phosphorus in reclaimed water ≤0.02 mg / L without using any additional phosphorus removal agents, thereby avoiding secondary pollution of the water environment caused by metal ions.

[0005] In order to achieve the above object, the present invention provides a device for limiting removal of inactive phosphorus in reclaimed water, comprising:

[0006] A water inlet tank, the water inlet of which is used to connect with the recycled water pipeline;

[0007] The dephosphorization filter tank is a metal tank body, and the dephosphorization filter tank comprises an aeration plate at the bottom and a metal dephosphorization adsorbent at the top, and the aeration plate is connected to the water outlet of the water inlet tank;

[0008] An ozone system connected to the aeration plate at the bottom of the dephosphorization filter tank;

[0009] A water production tank is connected to the space above the metal dephosphorization adsorbent in the dephosphorization filter tank, and a backwash water inlet of the water production tank is connected to the aeration disk through a backwash system;

[0010] An online monitoring system connected to the water inlet tank, the phosphorus removal filter tank and the water production tank;

[0011] The automatic control system is connected to the valve and the self-cleaning filter on the water inlet tank, the ozone system and the backwash system.

[0012] Optionally, the water inlet of the water inlet tank is provided with a water inlet pipe, the water inlet pipe is provided with the self-cleaning filter, the water inlet tank is also provided with an overflow port and a drain port, and a first SS probe connected to the online monitoring system is provided in the water inlet tank.

[0013] Optionally, a drainage pipe is provided between the water inlet tank and the dephosphorization filter tank, a water inlet pump connected to the automatic control system is provided on the drainage pipe, and a water outlet pipe is provided between the dephosphorization filter tank and the produced water tank.

[0014] Optionally, the ozone system includes an ozone generator connected to the automatic control system, the ozone generator is connected to the dephosphorization filter tank through an air intake pipe, the air intake pipe is provided with an ozone gas flow meter and an ozone concentration detector, the top of the dephosphorization filter tank is provided with an exhaust pipe, the exhaust pipe is provided with a concentration detector and an exhaust destructor.

[0015] Optionally, the backwash system includes a second SS probe, a backwash water pump and a backwash fan, the second SS probe is arranged in the water production tank, the backwash water pump is arranged on the backwash water pipe between the water production tank and the phosphorus removal filter tank, and the backwash fan is connected to the bottom of the water production tank.

[0016] Optionally, the particle size of the metal phosphorus removal adsorbent is 6 to 8 mm, the substrate of the metal phosphorus removal adsorbent is hydroxy iron, and the material bulk density of the metal phosphorus removal adsorbent is 1.2 to 1.5 t / m3.

[0017] The present invention also provides a method for limiting removal of inactive phosphorus in reclaimed water, using the above-mentioned device for limiting removal of inactive phosphorus in reclaimed water, the removal method comprises:

[0018] Discharge the regenerated water into the water inlet tank, and control the water inlet valve, drain valve and water discharge valve of the water inlet tank according to the concentration range of suspended solids in the water inlet tank;

[0019] Discharge the outlet water of the water inlet tank and the gas of the ozone system into the dephosphorization filter tank, and control the discharge amount of ozone according to the concentration range of inactive phosphorus in the water inlet tank;

[0020] The effluent from the dephosphorization filter tank is discharged into the production water tank, and the operation state of the backwash system is controlled according to the concentration range of suspended solids in the production water tank.

[0021] Optionally, when the concentration of suspended solids in the water inlet tank is higher than 10 mg / L, the drain valve of the water inlet tank and the self-cleaning filter are opened, and the drain valve of the water inlet tank is closed;

[0022] When the concentration of suspended solids in the water inlet tank is lower than 10 mg / L, the self-cleaning filter of the water inlet tank is closed and the drain valve of the water inlet tank is opened.

[0023] Optionally, the inactive phosphorus concentration of the water inlet tank is in the range of 0.02 to 0.1 mg / L, and the amount of ozone discharged from the ozone system into the dephosphorization filter tank is set to 15 to 30 mg / L.

[0024] Optionally, when the concentration of suspended solids in the production water tank is greater than 5 mg / L, the backwash system is started, and the cleaning methods of the backwash system include air washing, water washing and air-water washing.

[0025] The present invention provides a device and method for limiting removal of inactive phosphorus in reclaimed water, which has the following beneficial effects:

[0026] 1. This removal method can achieve efficient removal of inactive phosphorus in reclaimed water, with the total phosphorus in the effluent ≤0.02mg / L, and the water quality reaches Class III surface water, which can significantly reduce the risk of algal blooms in the water environment;

[0027] 2. This removal method is the first to couple ozone advanced oxidation technology with adsorption phosphorus removal technology, achieving "zero" addition of phosphorus removal agents while the effluent reaches the ultimate low phosphorus concentration;

[0028] 3. This removal method has a high degree of automation, is easy to operate, and has a long replacement cycle for phosphorus removal filter materials, which reduces the labor cost of frequent replacement of filter materials;

[0029] 4. This removal method efficiently integrates two treatment technologies, replacing the traditional ozone contact tank, which can significantly save land and reduce civil construction costs by more than 50%.

[0030] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The above and other objects, features and advantages of the present invention will become more apparent through a more detailed description of exemplary embodiments of the present invention in conjunction with the accompanying drawings, wherein like reference numerals generally represent like components throughout the exemplary embodiments of the present invention.

[0032] Figure 1 A schematic structural diagram of a device for limiting removal of inactive phosphorus in reclaimed water according to an embodiment of the present invention is shown.

[0033] Figure 2 A control principle diagram of a device for limiting removal of inactive phosphorus in reclaimed water according to an embodiment of the present invention is shown.

[0034] Figure 3 A flow chart of a method for limiting removal of inactive phosphorus in reclaimed water according to an embodiment of the present invention is shown.

[0035] Figure 4 A graph showing the real-time changes in the phosphate content in the inlet and outlet water during the operation of a device for limiting removal of inactive phosphorus in reclaimed water according to an embodiment of the present invention is shown.

[0036] Description of reference numerals:

[0037] 1. Inlet water tank; 2. Phosphorus removal filter tank; 3. Aeration plate; 4. Metal phosphorus removal adsorbent; 5. Water production tank; 6. Online monitoring system; 7. Automatic control system; 8. Self-cleaning filter; 9. Inlet pump; 10. Ozone generator; 11. Ozone gas flow meter; 12. Concentration detector; 13. Tail gas destroyer; 14. Backwash water pump; 15. Backwash fan. DETAILED DESCRIPTION

[0038] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present invention more thorough and complete, and to fully convey the scope of the present invention to those skilled in the art.

[0039] The present invention provides a device for limiting removal of inactive phosphorus in reclaimed water, comprising:

[0040] A water inlet tank, the water inlet of which is used to connect with the recycled water pipeline;

[0041] The phosphorus removal filter tank is a metal tank body, and the phosphorus removal filter tank includes an aeration plate at the bottom and a metal phosphorus removal adsorbent at the top, and the aeration plate is connected to the water outlet of the water inlet tank;

[0042] Ozone system, connected to the aeration plate at the bottom of the phosphorus removal filter tank;

[0043] The water production tank is connected to the space above the metal dephosphorization adsorbent in the dephosphorization filter tank, and the backwash water inlet of the water production tank is connected to the aeration disk through the backwash system;

[0044] Online monitoring system, connected with the inlet water tank, phosphorus removal filter tank and produced water tank;

[0045] Automatic control system, connected with valves and self-cleaning filter on water inlet tank as well as ozone system and backwash system control.

[0046] Specifically, the removal device discharges the regenerated water into the inlet water tank, and monitors the concentration of suspended solids in the inlet water tank through an online monitoring system to control the inlet water tank to drain water to the dephosphorization filter tank; while the inlet water tank is draining water to the dephosphorization filter tank, the ozone system also injects ozone gas into the dephosphorization filter tank, and an aeration plate is arranged at the bottom of the dephosphorization filter tank, which can increase the combination area of ​​ozone and water and improve the oxidation efficiency, and then after adsorption treatment by a metal dephosphorization adsorbent, it can absorb the oxidized inactive phosphorus and orthophosphate in the regenerated water, and at the same time play a role in filtering SS and particulate phosphorus; the production water tank collects the effluent from the dephosphorization filter tank, and when the online monitoring system detects that the concentration of suspended solids in the production water tank exceeds the standard, the water in the production water tank can be used to flush the dephosphorization filter tank through the backwash system. The online monitoring system in the removal device mainly includes an online phosphate detection device and an online SS detection device, a signal transmission module and a display screen, etc., wherein the phosphate online sampler is arranged in the inlet water tank and the production water tank, and samples are taken every hour to detect the total phosphorus and orthophosphate concentrations, and the difference between the two concentrations is the inactive phosphorus concentration; the SS probe is located in the inlet water tank and the production water tank, and is used to monitor the SS changes in the water tank, so as to facilitate the timely start of the self-cleaning filter and the phosphorus removal filter tank backwashing program; in addition, the automatic control system is connected with the online monitoring system, the water pump of the inlet water tank, the self-cleaning filter, the ozone system and the backwashing system, so as to realize the real-time adjustment of the ozone dosage, the start and stop of the self-cleaning filter, and the flow rate and backwashing time of the backwashing water and backwashing gas of the phosphorus removal filter tank.

[0047] Optionally, the water inlet of the water inlet tank is provided with an inlet pipe, the water inlet pipe is provided with a self-cleaning filter, the water inlet tank is also provided with an overflow port and a drain port, and a first SS probe connected to the online monitoring system is provided in the water inlet tank.

[0048] Specifically, an inlet, an overflow and an outlet are arranged on the water inlet tank, and a drain port is arranged at the bottom. The recycled water is discharged into the water inlet tank through the inlet pipe. A self-cleaning filter is installed on the water inlet pipe. An online SS probe is installed in the water tank. When the SS in the water tank exceeds 10 mg / L, it is necessary to open the drain valve of the water inlet tank, close the water inlet valve of the phosphorus removal filter tank, and start the self-cleaning filter at the same time to reduce the influence of the inlet SS on the subsequent phosphorus removal filter material and ozone oxidation efficiency.

[0049] Optionally, a drainage pipe is provided between the water inlet tank and the dephosphorization filter tank, a water inlet pump connected to the automatic control system is provided on the drainage pipe, and a water outlet pipe is provided between the dephosphorization filter tank and the produced water tank.

[0050] Specifically, the drainage from the phosphorus removal filter tank enters the water production tank. At the same time, the water in the water production tank is also used as backwash water for the phosphorus removal filter tank. An online phosphate sampler and an online SS probe are installed inside the tank to monitor the effluent water quality in real time.

[0051] Optionally, the ozone system includes an ozone generator connected to an automatic control system, the ozone generator is connected to the dephosphorization filter tank through an air intake pipe, an ozone gas flow meter and an ozone concentration detector are provided on the air intake pipe, an exhaust pipe is provided on the top of the dephosphorization filter tank, and a concentration detector and an exhaust destructor are provided on the exhaust pipe.

[0052] Specifically, the ozone system adjusts the amount of ozone added to the dephosphorization filter tank in real time by controlling the output power of the ozone generator and the valve opening of the gas flowmeter. The calculation method of the ozone dosage is: (ozone intake concentration-exhaust concentration)*flow*time / water volume, and the exhaust gas destroyer is used to decompose the unreacted ozone; when the inactive phosphorus concentration in the water inlet tank is less than 0.02mg / L, the amount of ozone in the dephosphorization filter tank is controlled to be 5-10mg / L, when the inactive phosphorus concentration is greater than 0.02mg / L and less than 0.1mg / L, the amount of ozone in the dephosphorization filter tank is controlled to be 15-30mg / L, and when the inactive phosphorus concentration is greater than 0.1mg / L and less than 0.3mg / L, the amount of ozone in the dephosphorization filter tank is controlled to be 30-60mg / L.

[0053] Optionally, the backwash system includes a second SS probe, a backwash water pump and a backwash fan. The second SS probe is arranged in the water production tank, the backwash water pump is arranged on the backwash water pipe between the water production tank and the phosphorus removal filter tank, and the backwash fan is connected to the bottom of the water production tank.

[0054] Specifically, during the operation of the backwash system, when the SS in the water tank exceeds 5 mg / L, the backwash procedure of the phosphorus removal filter tank is started. The backwash procedure includes air washing for 5 to 10 minutes, air-water washing for 10 to 20 minutes, and water washing for 10 to 15 minutes. The air washing intensity is 10 to 15 L / (m 2·s), the air washing intensity remains unchanged during air-water washing, and the water washing intensity is 2~3L / (m 2 ·s), the water washing intensity when washing with water alone is 3.5~5L / (m 2 ·s).

[0055] Optionally, the particle size of the metal phosphorus removal adsorbent is 6 to 8 mm, the substrate of the metal phosphorus removal adsorbent is hydroxy iron, and the material bulk density of the metal phosphorus removal adsorbent is 1.2 to 1.5 t / m3.

[0056] Specifically, the metal dephosphorization adsorbent in the dephosphorization filter tank is a composite metal material with a particle size of 6-8 mm. This particle size range can give full play to the optimal adsorption performance of the dephosphorization material, which can not only achieve efficient removal of phosphorus, but also avoid the loss of materials during backwashing; the base material of the metal dephosphorization adsorbent is hydroxy iron and loaded with rare earth metals. The material bulk density is 1.2-1.5 t / m 3 , the material filling volume is 50% to 70% of the effective volume of the tank.

[0057] The present invention also provides a method for limiting removal of inactive phosphorus in reclaimed water, using the above-mentioned device for limiting removal of inactive phosphorus in reclaimed water, the removal method comprises:

[0058] Discharge the regenerated water into the inlet tank, and control the inlet valve, drain valve and drain valve of the inlet tank according to the concentration range of suspended solids in the inlet tank;

[0059] The water from the inlet tank and the gas from the ozone system are discharged into the dephosphorization filter tank, and the amount of ozone discharged is controlled according to the concentration range of inactive phosphorus in the inlet tank;

[0060] The effluent from the dephosphorization filter tank is discharged into the production water tank, and the operating state of the backwash system is controlled according to the concentration range of suspended solids in the production water tank.

[0061] Optionally, when the concentration of suspended solids in the inlet tank is higher than 10 mg / L, open the drain valve and self-cleaning filter of the inlet tank, and close the drain valve of the inlet tank; when the concentration of suspended solids in the inlet tank is lower than 10 mg / L, close the self-cleaning filter of the inlet tank and open the drain valve of the inlet tank.

[0062] Optionally, the inactive phosphorus concentration of the water inlet tank ranges from 0.02 to 0.1 mg / L, and the amount of ozone discharged into the deozonation system is set to 15 to 30 mg / L.

[0063] Optionally, when the concentration of suspended solids in the production water tank is greater than 5 mg / L, the backwash system is started, and the cleaning methods of the backwash system include air washing, water washing and air-water washing.

[0064] Specifically, the method for extreme removal of inactive phosphorus in reclaimed water solves the problems of high inactive phosphorus concentration in the effluent of reclaimed water plants and ineffectiveness of conventional phosphorus removal methods, provides feasible technical methods and treatment devices, solves the drawbacks of existing phosphorus removal methods in reclaimed water plants, and achieves total phosphorus in effluent ≤0.02 mg / L, meets the standards for safe utilization of the water environment, and reduces the risk of algal blooms.

[0065] Example

[0066] like Figures 1 to 4 As shown, the present invention provides a device for limiting removal of inactive phosphorus in reclaimed water, comprising:

[0067] A water inlet tank 1, the water inlet of which is used to connect to the recycled water pipeline;

[0068] The dephosphorization filter tank 2 is a metal tank body, and the dephosphorization filter tank 2 includes an aeration plate 3 at the bottom and a metal dephosphorization adsorbent 4 at the top, and the aeration plate 3 is connected to the water outlet of the water inlet tank 1;

[0069] An ozone system is connected to the aeration plate 3;

[0070] The water production tank 5 is connected to the space above the metal dephosphorization adsorbent 4 in the dephosphorization filter tank 2, and the backwash water inlet of the water production tank 5 is connected to the aeration plate 3 through the backwash system;

[0071] The online monitoring system 6 is connected to the inlet water tank 1, the dephosphorization filter tank 2 and the produced water tank 5;

[0072] The automatic control system 7 is connected to the valve on the water inlet tank 1, the self-cleaning filter 8, the ozone system and the backwash system.

[0073] In this embodiment, the water inlet of the water inlet tank 1 is provided with a water inlet pipe, the water inlet pipe is provided with a self-cleaning filter 8, the water inlet tank 1 is also provided with an overflow port and a drain port, and the water inlet tank 1 is provided with a first SS probe connected to the online monitoring system.

[0074] In this embodiment, a drainage pipe is provided between the water inlet tank 1 and the dephosphorization filter tank 2 , and a water inlet pump 9 connected to the automatic control system is provided on the drainage pipe; and a water outlet pipe is provided between the dephosphorization filter tank 2 and the produced water tank 5 .

[0075] In this embodiment, the ozone system includes an ozone generator 10 connected to an automatic control system. The ozone generator 10 is connected to the dephosphorization filter tank 2 through an air intake pipe. An ozone gas flow meter 11 and an ozone concentration detector are provided on the air intake pipe. An exhaust pipe is provided on the top of the dephosphorization filter tank 2. A concentration detector 12 and an exhaust destructor 13 are provided on the exhaust pipe.

[0076] In this embodiment, the backwash system includes a second SS probe, a backwash water pump 14 and a backwash fan 15. The second SS probe is arranged in the water production tank 5, the backwash water pump 14 is arranged on the backwash water pipe between the water production tank 5 and the phosphorus removal filter tank 2, and the backwash fan 15 is connected to the bottom of the water production tank 5.

[0077] In this embodiment, the particle size of the metal dephosphorization adsorbent 4 is 6-8 mm, the base material of the metal dephosphorization adsorbent 4 is hydroxy iron, and the material bulk density of the metal dephosphorization adsorbent 4 is 1.2-1.5 t / m3.

[0078] The present invention also provides a method for limiting removal of inactive phosphorus in reclaimed water, using the above-mentioned device for limiting removal of inactive phosphorus in reclaimed water, the removal method comprises:

[0079] Discharge the regenerated water into the inlet water tank 1, and control the inlet valve, self-cleaning filter 8, drain valve and drain valve of the inlet water tank 1 according to the concentration range of suspended solids in the inlet water tank 1;

[0080] The water from the inlet tank 1 and the gas from the ozone system are discharged into the dephosphorization filter tank 2, and the amount of ozone discharged is controlled according to the concentration range of inactive phosphorus in the inlet tank 1;

[0081] The effluent from the dephosphorization filter tank 2 is discharged into the water production tank 5 , and the operation state of the backwash system is controlled according to the concentration range of suspended solids in the water production tank 5 .

[0082] In this embodiment, when the concentration of suspended solids in the inlet water tank 1 is higher than 10 mg / L, the drain valve of the inlet water tank 1 and the self-cleaning filter 8 are opened, and the drain valve of the inlet water tank 1 is closed;

[0083] When the concentration of suspended solids in the inlet water tank 1 is lower than 10 mg / L, the self-cleaning filter 8 of the inlet water tank 1 is closed and the drain valve of the inlet water tank 1 is opened.

[0084] In this embodiment, the inactive phosphorus concentration of the water inlet tank 1 is in the range of 0.02 to 0.1 mg / L, and the amount of ozone discharged into the deozonation system is set to 15 to 30 mg / L.

[0085] In this embodiment, when the concentration of suspended solids in the production water tank 5 is greater than 5 mg / L, the backwash system is started, and the backwash system has a cleaning method including an air wash method, a water wash method, and an air-water wash method.

[0086] In summary, the limit removal device is used in a reclaimed water plant, where the filtered water volume of the self-cleaning filter is 1 to 5 m 3 / h, the filtration accuracy is 25-300μm, and the device can be started and stopped at any time through the automatic control system. When the SS in the water tank is higher than 10mg / L, the water tank drain valve is opened and the dephosphorization filter tank water inlet valve and water pump are closed. After the drain is completed, the self-cleaning filter is started and the water tank drain valve is closed. When the SS is less than 10mg / L, the self-cleaning filter is closed and the dephosphorization filter tank water inlet valve and water pump are opened; the ozone generator output is 25g / h, the power is 900W, and the corresponding gas flow The meter, ozone concentration detector and tail gas destroyer are supporting devices, which are provided by the ozone generator manufacturer; during the operation of the device, the inactive phosphorus concentration in the water tank ranges from 0.02 to 0.1 mg / L, and the ozone amount in the phosphorus removal filter tank is controlled to be 15 to 30 mg / L; the adsorption phosphorus removal filter tank is 1.2m high, 0.85m high inside, 0.4m in diameter, the filling mass of the metal phosphorus removal adsorbent is 95kg, the filling height is 0.51m, accounting for 60% of the effective volume of the filter tank, and the water volume of the filter tank is 1m 3 / h, hydraulic retention time is 20min; titanium aeration plate is installed under the adsorbent, ozone and backwash gas can be introduced, there is a support layer between the aeration plate and the dephosphorization adsorbent, the space height between the support layer and the bottom of the filter tank is 0.1m, which is convenient for ozone and influent water to be fully mixed; when the SS in the water tank exceeds 5mg / L, the dephosphorization filter tank backwashing procedure is started, air washing for 5min, air-water washing for 20min, water washing for 10min, and the air washing intensity is 12L / (m 2 ·s), the air washing intensity remains unchanged during air-water washing, and the water washing intensity is 3L / (m 2 ·s), the water washing intensity for simple water washing is 4L / (m 2 ·s), close the filter tank water inlet valve and ozone generator during backwashing. If SS is too high, repeat the above backwashing process 1 to 2 times.

[0087] During the operation of the device, the phosphate content (total phosphorus and orthophosphate) in the inlet and outlet water was monitored in real time, and the 24-hour average was used to draw a curve to analyze the effect of continuous operation for 30 days. The results showed that when the total phosphorus in the inlet water was ≤0.2 mg / L and the inactive phosphorus was ≤0.1 mg / L, the inactive phosphorus in the outlet water of the device was ≤0.01 mg / L and the total phosphorus was stable ≤0.02 mg / L, reaching the surface water quality of Class III and meeting the design requirements. The specific data are as follows: Figure 4 shown.

[0088] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A device for limiting removal of inactive phosphorus in reclaimed water, characterized in that: include: A water inlet tank, the water inlet of which is used to connect with the recycled water pipeline; The dephosphorization filter tank is a metal tank body, and the dephosphorization filter tank comprises an aeration plate at the bottom and a metal dephosphorization adsorbent at the top, and the aeration plate is connected to the water outlet of the water inlet tank; An ozone system connected to the aeration plate at the bottom of the dephosphorization filter tank; A water production tank is connected to the space above the metal dephosphorization adsorbent in the dephosphorization filter tank, and a backwash water inlet of the water production tank is connected to the aeration disk through a backwash system; An online monitoring system connected to the water inlet tank, the phosphorus removal filter tank and the water production tank; The automatic control system is connected to the valve and the self-cleaning filter on the water inlet tank, the ozone system and the backwash system.

2. The device for limiting removal of inactive phosphorus in reclaimed water according to claim 1, characterized in that: The water inlet of the water inlet tank is provided with a water inlet pipe, the water inlet pipe is provided with the self-cleaning filter, the water inlet tank is also provided with an overflow port and a drain port, and the water inlet tank is provided with a first SS probe connected to the online monitoring system.

3. The device for limiting removal of inactive phosphorus in reclaimed water according to claim 1, characterized in that: A drainage pipe is arranged between the water inlet tank and the dephosphorization filter tank, and a water inlet pump connected to the automatic control system is arranged on the drainage pipe. A water outlet pipe is arranged between the dephosphorization filter tank and the produced water tank.

4. The device for limiting removal of inactive phosphorus in reclaimed water according to claim 1, characterized in that: The ozone system comprises an ozone generator connected to the automatic control system, the ozone generator is connected to the dephosphorization filter tank through an air intake pipe, an ozone gas flow meter and an ozone concentration detector are arranged on the air intake pipe, an exhaust pipe is arranged on the top of the dephosphorization filter tank, and a concentration detector and an exhaust destructor are arranged on the exhaust pipe.

5. The device for limiting removal of inactive phosphorus in reclaimed water according to claim 1, characterized in that: The backwash system includes a second SS probe, a backwash water pump and a backwash fan. The second SS probe is arranged in the water production tank, the backwash water pump is arranged on the backwash water pipe between the water production tank and the dephosphorization filter tank, and the backwash fan is connected to the aeration plate at the bottom of the dephosphorization filter tank.

6. The device for limiting removal of inactive phosphorus in reclaimed water according to claim 1, characterized in that: The particle size of the metal dephosphorization adsorbent is 6-8 mm, the base material of the metal dephosphorization adsorbent is hydroxy iron, and the material bulk density of the metal dephosphorization adsorbent is 1.2-1.5 t / m 3 .

7. A method for the ultimate removal of inactive phosphorus in reclaimed water, using the device for the ultimate removal of inactive phosphorus in reclaimed water according to any one of claims 1 to 6, characterized in that: The removal methods include: Discharge the regenerated water into the water inlet tank, and control the water inlet valve, drain valve and water discharge valve of the water inlet tank according to the concentration range of suspended solids in the water inlet tank; Discharge the outlet water of the water inlet tank and the gas of the ozone system into the dephosphorization filter tank, and control the discharge amount of ozone according to the concentration range of inactive phosphorus in the water inlet tank; The effluent from the dephosphorization filter tank is discharged into the production water tank, and the operation state of the backwash system is controlled according to the concentration range of suspended solids in the production water tank.

8. The method for limiting removal of inactive phosphorus in reclaimed water according to claim 7, characterized in that: When the concentration of suspended solids in the water inlet tank is higher than 10 mg / L, the drain valve of the water inlet tank and the self-cleaning filter are opened, and the drain valve of the water inlet tank is closed; When the concentration of suspended solids in the water inlet tank is lower than 10 mg / L, the self-cleaning filter of the water inlet tank is closed and the drain valve of the water inlet tank is opened.

9. The method for limiting removal of inactive phosphorus in reclaimed water according to claim 7, characterized in that: The inactive phosphorus concentration of the water inlet tank ranges from 0.02 to 0.1 mg / L, and the amount of ozone discharged from the ozone system into the dephosphorization filter tank is set to 15 to 30 mg / L.

10. The method for limiting removal of inactive phosphorus in reclaimed water according to claim 7, characterized in that: When the concentration of suspended solids in the water production tank is greater than 5 mg / L, the backwash system is started, and the cleaning methods of the backwash system include air washing, water washing and air-water washing.

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