Responsive intelligent anti-fouling quartz sand filter material filter based on CO2

Abstract

The invention relates to a CO2-based response type intelligent anti-fouling quartz sand filter material filter. The filter comprises a tank body, a separation filter material with adjustable wettability is arranged in the tank body, and the separation filter material is a CO2 response type intelligent anti-pollution quartz sand filter material; an exhaust port is formed in the top of the tank body, an air inlet structure is arranged at the bottom of the tank body, and the air inlet structure is used for introducing air for regulating and controlling the wettability of the separation filter material; the tank body is provided with a liquid inlet used for injecting mixed liquid above the separation filter material, the bottom of the tank body is provided with a liquid outlet and a backwashing liquid inlet, and the tank body is provided with a backwashing liquid outlet. The wettability of the separation filter material is adjusted, so that the separation filter material is oleophylic and hydrophobic during filtration, the separation filter material is hydrophilic and oleophobic during backwashing, the separation filter material has different wettability in a filtration stage and a backwashing stage, the recycling efficiency of the filter material can be greatly improved, the service life of the filter material is prolonged, and the method is suitable for industrial application.

Description

Technical Field

[0001] This invention relates to the field of oily wastewater treatment in the petrochemical industry, and particularly to a CO2-responsive intelligent antifouling quartz sand filter. Background Technology

[0002] Global oilfield wastewater production is approximately 250 million barrels per day, and the composition of oily wastewater is extremely complex. Therefore, direct discharge without any treatment will cause severe pollution of surface water, groundwater, and soil. All types of oily wastewater must be treated before further processing. Filters are currently a commonly used device for treating oily wastewater, offering high throughput, excellent separation efficiency, and effective removal of oil and suspended solids from the water.

[0003] However, prolonged use of filters can lead to clogging and compaction of the filter media within the tank, significantly reducing the filter's processing efficiency. Most commonly used filter media are oleophilic and hydrophobic, offering good oil absorption, but their inherent wettability hinders backwashing. Therefore, the application of filter media with adjustable wettability is essential. Furthermore, current filter backwashing primarily relies on manual cleaning or the addition of agitators during the rinsing process, increasing backwashing costs. The backwashing process is complex, often insufficient, and results in low media recycling rates, further increasing costs. In summary, current filtration processes suffer from low petroleum hydrocarbon retention rates, easy media compaction and failure, and difficulties in backwashing.

[0004] Therefore, based on years of experience and practice in related industries, the inventor proposes a CO2-responsive intelligent anti-fouling quartz sand filter to overcome the shortcomings of existing technologies. Summary of the Invention

[0005] The purpose of this invention is to provide a CO2-responsive intelligent anti-fouling quartz sand filter media, which solves the problems of low petroleum rejection rate, easy caking and failure of filter media, and difficulty in backwashing in current filtration processes. This invention applies filter media with adjustable wettability to the filter. By adjusting the wettability of the separating filter media, the separating filter media is oleophilic and hydrophobic during filtration and hydrophilic and oleophobic during backwashing. This enhances the different wettability of the separating filter media in the filtration and backwashing stages, which can greatly improve the recycling efficiency of the filter media and extend its service life, making it suitable for industrial applications.

[0006] The objective of this invention is achieved as follows: a CO2-responsive intelligent antifouling quartz sand filter includes a tank; the tank contains adjustable wettability separation filter media, which is CO2-responsive intelligent antifouling quartz sand filter media; an exhaust port is provided at the top of the tank, and an air inlet structure is provided at the bottom of the tank for introducing gas that regulates the wettability of the separation filter media; an inlet for injecting a mixed liquid is provided above the separation filter media in the tank, an outlet and a backwash liquid inlet are provided at the bottom of the tank, and a backwash liquid outlet is provided on the top of the tank;

[0007] When filtering the mixture, the separation filter media is oleophilic and hydrophobic. The separation filter media adsorbs and filters oil droplets in the mixture, and the aqueous phase separated by the filtration is discharged through the outlet. During backwashing, CO2 gas is introduced through the air inlet structure to make the separation filter media hydrophilic and oleophobic, and the CO2 gas expands and fluidizes the separation filter media. Backwash liquid is injected through the backwash liquid inlet for backwashing, and the product after backwashing is discharged from the backwash liquid outlet. After backwashing, N2 gas is introduced to make the separation filter media oleophilic and hydrophobic.

[0008] In a preferred embodiment of the present invention, the separation filter material includes granular filter material. A modified solution is sprayed onto the surface of the granular filter material to make it CO2 responsive. After the modified solution adheres to the granular filter material, the separation filter material can be transformed from oleophilic and hydrophobic to hydrophilic and oleophobic by introducing CO2 gas, and the separation filter material can be transformed from hydrophilic and oleophobic to oleophilic and hydrophobic by introducing N2 gas.

[0009] In a preferred embodiment of the present invention, the particle size of the particulate filter media is 0.6-0.8 mm.

[0010] In a preferred embodiment of the present invention, the tank body is provided with a rinsing port for injecting rinsing liquid between the separation filter material and the liquid inlet. The rinsing port is positioned opposite to and at the same height as the backwash liquid outlet. During backwashing, backwash liquid is injected from the backwash liquid inlet for backwashing, and then rinsing liquid is injected from the rinsing port to discharge the backwashed product from the backwash liquid outlet.

[0011] In a preferred embodiment of the present invention, a liner plate is provided inside the tank, the liner plate is provided with a plurality of through holes, and the separation filter material is supported on the liner plate.

[0012] In a preferred embodiment of the invention, the support plate is made of steel plate.

[0013] In a preferred embodiment of the present invention, a long-handled filter head is provided below the liner plate, and the two ends of the long-handled filter head are respectively connected to the air inlet structure and the backwash liquid inlet.

[0014] In a preferred embodiment of the present invention, the air inlet structure includes a first air inlet and a second air inlet arranged in parallel, wherein the first air inlet is used to introduce CO2 gas and the second air inlet is used to introduce N2 gas.

[0015] In a preferred embodiment of the present invention, a first valve is provided at the liquid inlet and a second valve is provided at the liquid outlet; a third valve is provided at the first air inlet, a fourth valve is provided at the second air inlet, and a fifth valve is provided at the exhaust outlet; a sixth valve is provided at the backwash liquid inlet, a seventh valve is provided at the backwash liquid outlet, and an eighth valve is provided at the flushing outlet.

[0016] In a preferred embodiment of the present invention, the expansion rate of the CO2 gas expanding fluidizing the separation filter media is 40%-50%.

[0017] In summary, the purpose of this invention is to provide a CO2-responsive intelligent antifouling quartz sand filter with the following beneficial effects:

[0018] This invention uses CO2-responsive intelligent antifouling quartz sand filter media to achieve intelligent control of the wettability of the separation filter media. It does not require disassembly of the device or replacement of the packing material, making it easy to operate and with low operating costs.

[0019] This invention enhances the backwashing effect of the separation filter media by changing its wettability. The introduction of a liquid-loving phase into the filter media can better clean the separation filter media thoroughly, improve backwashing efficiency, solve the problem of filter media caking, improve the oil removal rate of the filter, and ensure stable performance.

[0020] After backwashing, N2 gas is introduced to restore the wettability of the separation filter material to an oleophilic-hydrophobic type, which adsorbs oil droplets and allows for recycling.

[0021] During the backwashing process, a mixture of gas and liquid phases is used to increase the backwashing intensity, making the filter media backwash more thorough and the filter media reuse rate higher.

[0022] This invention modifies quartz sand to form a CO2-responsive intelligent antifouling quartz sand filter media, giving it hydrophilic-hydrophobic conversion function. Due to its stronger dirt-holding capacity, it has the advantage of simultaneously removing suspended solids compared to modification using corrugated plates, metal mesh, and other materials. It also solves the problem that the interface of corrugated plates or metal mesh modified materials is easily damaged by suspended solids, making it difficult to handle emulsions containing suspended solids, thus effectively ensuring the oil removal rate of the system. Attached Figure Description

[0023] The accompanying drawings are intended only to illustrate and explain the present invention and do not limit the scope of the invention.

[0024] in:

[0025] Figure 1 This is a schematic diagram of the CO2-responsive intelligent antifouling quartz sand filter of the present invention.

[0026] In the picture:

[0027] 1. Tank body;

[0028] 2. Fifth valve;

[0029] 3. Separate the filter media;

[0030] 4. Supporting plate;

[0031] 5. Exhaust port;

[0032] 6. Liquid inlet;

[0033] 7. Backwash solution outlet;

[0034] 8. Rinse port;

[0035] 9. First air intake;

[0036] 10. Second air intake;

[0037] 11. Long-handled filter head;

[0038] 12. Backwash solution inlet;

[0039] 13. First valve;

[0040] 14. Third valve;

[0041] 15. Fourth valve;

[0042] 16. Sixth valve;

[0043] 17. Seventh valve;

[0044] 18. The eighth valve;

[0045] 19. Transition pipe;

[0046] 20. Ninth valve. Detailed Implementation

[0047] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention will now be described with reference to the accompanying drawings.

[0048] The specific embodiments of the present invention described herein are for illustrative purposes only and should not be construed as limiting the invention in any way. Under the teachings of this invention, those skilled in the art can conceive of any possible modifications based on the invention, all of which should be considered within the scope of the invention. It should be noted that when an element is referred to as being "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or there may be an intervening element. The terms "mounted," "connected," and "linked" should be interpreted broadly; for example, they can refer to mechanical or electrical connections, or internal communication between two elements, and can be direct or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible embodiments.

[0049] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0050] like Figure 1 As shown, this invention provides a CO2-responsive intelligent antifouling quartz sand filter, including a tank 1; the tank 1 contains adjustable wettability separation filter media 3, which is CO2-responsive intelligent antifouling quartz sand filter media; an exhaust port 5 is provided at the top of the tank 1, and an air inlet structure is provided at the bottom of the tank 1 for introducing gas to regulate the wettability of the separation filter media; an inlet 6 for injecting a mixed liquid is provided above the separation filter media 3 in the tank 1, and an outlet and a backwash liquid inlet 12 are provided at the bottom of the tank 1, the backwash liquid inlet 12 can also serve as an outlet; a backwash liquid outlet 7 is provided on the tank 1;

[0051] When filtering the mixture, the separation filter media 3 is oleophilic and hydrophobic. The separation filter media 3 adsorbs the oil droplets in the filtered mixture, and the aqueous phase of the mixture separated by filtration is discharged through the outlet.

[0052] When the filter media 3 is saturated or contains a large number of solid particles, backwashing is performed. During backwashing, CO2 gas is introduced through the air inlet structure to convert the filter media 3 into a hydrophilic and oleophobic material. The CO2 gas expands and fluidizes the filter media 3, increasing its porosity and facilitating backwashing. In one embodiment, the expansion rate of the CO2 gas fluidizing the filter media is 40%-50%. Backwashing liquid is injected through the backwash liquid inlet for backwashing, and the product after backwashing is discharged from the backwash liquid outlet 7. The dual action of the gas and liquid phases makes the cleaning of the filter media 3 more thorough, greatly enhances the backwashing effect, increases the reuse rate of the filter media 3, and saves costs.

[0053] After backwashing, N2 gas is introduced to make the separation filter media 3 oleophilic and hydrophobic, so that it can be reused for oil-water separation.

[0054] This invention uses CO2-responsive intelligent antifouling quartz sand filter media to achieve intelligent control of the wettability of the separation filter media 3. It does not require disassembly of the device or replacement of the packing, making it easy to operate and with low operating costs.

[0055] This invention enhances the backwashing effect of the separation filter media 3 by changing its wettability. The introduction of a liquid-loving phase into the filter media can better clean the separation filter media 3 thoroughly, improve the backwashing efficiency, solve the problem of filter media caking, improve the oil removal rate of the filter, and ensure stable performance.

[0056] After backwashing, N2 gas is introduced to restore the wettability of the separation filter media 3 to an oleophilic-hydrophobic type, so that oil droplets can be adsorbed and reused.

[0057] During the backwashing process, a mixture of gas and liquid phases is used to increase the backwashing intensity, making the filter media backwash more thorough and the filter media reuse rate higher.

[0058] This invention modifies quartz sand to form a CO2-responsive intelligent antifouling quartz sand filter media, giving it hydrophilic-hydrophobic conversion function. Due to its stronger dirt-holding capacity, it has the advantage of simultaneously removing suspended solids compared to modification using corrugated plates, metal mesh, and other materials. It also solves the problem that the interface of corrugated plates or metal mesh modified materials is easily damaged by suspended solids, making it difficult to handle emulsions containing suspended solids, thus effectively ensuring the oil removal rate of the system.

[0059] Furthermore, the separation filter media 3 includes granular filter media. The modified solution is sprayed onto the surface of the granular filter media to make it CO2 responsive. After the modified solution adheres to the granular filter media, the separation filter media can be transformed from oleophilic and hydrophobic to hydrophilic and oleophobic by introducing CO2 gas, and the separation filter media can be transformed from hydrophilic and oleophobic to oleophilic and hydrophobic by introducing N2 gas.

[0060] The adjustable wettability separation filter media uses granular filter media quartz sand as the base material. Preferably, the particle size of the granular filter media is 0.6-0.8 mm. The modified solution is sprayed onto the surface of the granular filter media using a spraying method. The modified solution is prepared as follows:

[0061] 10g of the main surfactant AHY (obtained by a 1:1 mass ratio of cocoagulant polyoxyethylene ether PEG-n and fatty alcohol polyoxyethylene ether sodium sulfate AES), 10g of the amphiphilic solvent (n-propanol or isopropanol), and 20g of pure water were added to an Erlenmeyer flask. A switching solvent (cyclic: N,N-dimethylcyclohexylamine, N,N-dimethylbenzylamine, N,N-dimethylaniline; chain: N,N-dimethylbutylamine, N,N-dimethylhexylamine, N,N-dimethyloctylamine) was added in the same mass as the amphiphilic solvent. The mixture was stirred using a magnetic stirrer at 300 rpm for 30 minutes. The switching solvent was added as the oil phase during stirring. The mixture was then allowed to stand to check for stratification. If no stratification occurred, the modified solution was successfully prepared. This solution exhibits CO2 responsiveness; after adhering to a material, the introduction of CO2 can transform the material from oleophilic-hydrophobic to hydrophilic-oleophobic. The introduction of N2 can then revert the material's wettability back to oleophilic-hydrophobic.

[0062] Furthermore, such as Figure 1 As shown, the tank body 1 is located between the separation filter media 3 and the liquid inlet 6 and is provided with a flushing port 8 for injecting flushing liquid. The flushing port 8 and the backwash liquid outlet 7 are positioned opposite each other and at the same height. During backwashing, backwash liquid is injected from the backwash liquid inlet for backwashing, and then flushing liquid is injected from the flushing port 8 to discharge the backwashed product from the backwash liquid outlet 7.

[0063] During the backwashing process of the filter media 3, CO2 gas is introduced through the air inlet structure, changing the wettability of the filter media 3 from oleophilic to hydrophobic to hydrophilic to oleophobic. Simultaneously, the filter media 3 expands, increasing its porosity, which facilitates backwashing. Then, flowing water is introduced through the backwash liquid inlet and flushing port 8, using the water flow to thoroughly clean the filter media 3, carrying away solid particles and residual oil phase from the pores and reducing clogging. The dual action of the gas and liquid phases ensures more thorough cleaning of the filter media, greatly enhancing the backwashing effect, increasing the filter media reuse rate, and saving costs.

[0064] Furthermore, such as Figure 1 As shown, a liner plate 4 is installed inside the tank body 1. The liner plate 4 has several through holes, and the separation filter media 3 is supported on the liner plate 4. The separation filter media 3 is fixed by the liner plate 4.

[0065] Furthermore, the support plate 4 is made of steel plate.

[0066] Furthermore, such as Figure 1As shown, a long-handled filter head 11 is provided below the support plate 4, and the two ends of the long-handled filter head 11 are connected to the air inlet structure and the backwash liquid inlet 12, respectively.

[0067] Furthermore, such as Figure 1 As shown, the air inlet structure includes a first air inlet 9 and a second air inlet 10 arranged in parallel. The first air inlet 9 is used to introduce CO2 gas, and the second air inlet 10 is used to introduce N2 gas.

[0068] Furthermore, such as Figure 1 As shown, to facilitate the input and output control of gas and liquid phases, a first valve 13 is installed at the liquid inlet 6, and a second valve is installed at the liquid outlet; a third valve 14 is installed at the first air inlet 9, a fourth valve 15 is installed at the second air inlet 10, and a fifth valve 2 is installed at the exhaust outlet 5; a sixth valve 16 is installed at the backwash liquid inlet, a seventh valve 17 is installed at the backwash liquid outlet 7, and an eighth valve 18 is installed at the flushing outlet 8.

[0069] Furthermore, such as Figure 1 As shown, the backwash fluid inlet 12 can be connected to the flushing port 8 through the transition pipe 19. The inlet of the transition pipe 19 is equipped with a ninth valve 20. The backwash fluid inlet 12 can be connected to a peristaltic pump (existing technology) to pump water in and supply backwash fluid or flushing fluid (generally water).

[0070] Example

[0071] like Figure 1 As shown, a CO2-responsive intelligent antifouling quartz sand filter includes a tank 1. An inlet 6 for introducing a mixed liquid is located on the left side of the tank 1, which can be connected to a peristaltic pump to pump the mixed liquid in. The filter media 3 inside the tank 1 is fixed by a support plate 4. A long-handled filter head 11 is connected to the bottom of the tank 1. One end of the long-handled filter head 11 has a first air inlet 9 (CO2) and a second air inlet 10 (N2). An exhaust port 5 is located at the top of the tank 1 to allow the introduction and discharge of CO2 and N2. A backwash liquid inlet 12 is located at the other end of the long-handled filter head 11, which can be connected to a peristaltic pump to pump water in. Additionally, the backwash liquid inlet 12 can also serve as an outlet. A backwash liquid outlet 7 is located on the left side of the tank 1, above the filter media, to facilitate filter media expansion and fluidization. A flushing port 8 is located on the right side of the tank 1 at the same height to flush out floating solid particles.

[0072] Working principle:

[0073] When using this invention, the inlet 6 and outlet are connected to the corresponding external devices, and the other channel valves are closed. The mixture enters the interior of the tank 1 through the inlet 6, and then passes through the separation filter media 3, where the oil phase is adsorbed by the filter media and separated from the water phase. Finally, the filtered filtrate is discharged from the outlet.

[0074] When the filter media is saturated or contains a large number of solid particles in the pores, backwashing of the separation filter media 3 is required. First, close the first valve 13 at the liquid inlet 6 and the second valve at the liquid outlet, then open the third valve 14 at the first air inlet 9 to introduce CO2 gas. This changes the wettability of the separation filter media 3 from oleophilic to hydrophobic to hydrophilic to oleophobic, with a conveying intensity of approximately 17-25 L / m³. 2 • h, purge for about 5-10 minutes, which simultaneously allows the separation filter media 3 to expand and fluidize, with an expansion rate of about 40%-50%, facilitating backwashing. Gas is discharged from exhaust port 5, and then the sixth valve 16 at the backwash liquid inlet 12 is opened at 30-40 L / m 2 A flow rate of h is used to pass water through for thorough cleaning. Water is introduced through the flushing port 8 to carry out impurities and residual oil phase, which flow out through the backwash liquid outlet 7. The dual action of the gas phase and liquid phase can make the cleaning of the separation filter media 3 more thorough and greatly enhance the backwashing effect.

[0075] Finally, close the valve and open the fourth valve 15 at the second air inlet 10 to introduce N2. The gas is discharged from the exhaust port 5, which changes the wettability of the separation filter material 3 back to oleophilic and hydrophobic, allowing it to be reused for oil-water separation, greatly saving costs.

[0076] Performance testing:

[0077] Oily wastewater was filtered using the CO2-responsive intelligent antifouling quartz sand filter of this invention. The separated filter media 3 was backwashed and circulated ten times. The oil content and suspended solids content of the mixture before and after treatment were measured. All test results met the limits of the Integrated Wastewater Discharge Standard GB 8978-1996. Two sets of tests were conducted. Example 1 used CO2-responsive intelligent antifouling quartz sand filter as the filter media to filter a mixture with an oil content of 500 mg / L and a suspended solids content of 200 mg / L before treatment. Example 2 used CO2-responsive intelligent antifouling quartz sand filter as the filter media to filter a mixture with an oil content of 1000 mg / L and a suspended solids content of 500 mg / L before treatment. The test results are shown in Table 1.

[0078] Example 3 uses metal mesh filter media to filter a mixture with an oil content of 1000 mg / L and suspended solids of 500 mg / L before treatment. Example 4 uses corrugated plate filter media to filter a mixture with an oil content of 1000 mg / L and suspended solids of 500 mg / L before treatment. The comparison results between Example 2 and Example 3 are shown in Table 2, and the comparison results between Example 2 and Example 4 are shown in Table 3.

[0079] Compared to common ordinary filters, which have an oil removal efficiency of about 70%, the CO2-responsive intelligent antifouling quartz sand filter of this invention has a significantly improved oil removal rate for oily wastewater, reaching 97%. Furthermore, after switching wettability and backwashing, the problem of filter media clogging is solved, and the number of cycles is greatly increased.

[0080]

[0081] Table 1

[0082]

[0083] Table 2

[0084]

[0085] Table 3

[0086] In summary, the purpose of this invention is to provide a CO2-responsive intelligent antifouling quartz sand filter with the following beneficial effects:

[0087] This invention uses CO2-responsive intelligent antifouling quartz sand filter media to achieve intelligent control of the wettability of the separation filter media. It does not require disassembly of the device or replacement of the packing material, making it easy to operate and with low operating costs.

[0088] This invention enhances the backwashing effect of the separation filter media by changing its wettability. The introduction of a liquid-loving phase into the filter media can better clean the separation filter media thoroughly, improve backwashing efficiency, solve the problem of filter media caking, improve the oil removal rate of the filter, and ensure stable performance.

[0089] After backwashing, N2 gas is introduced to restore the wettability of the separation filter material to an oleophilic-hydrophobic type, which adsorbs oil droplets and allows for recycling.

[0090] During the backwashing process, a mixture of gas and liquid phases is used to increase the backwashing intensity, making the filter media backwash more thorough and the filter media reuse rate higher.

[0091] This invention modifies quartz sand to form a CO2-responsive intelligent antifouling quartz sand filter media, giving it hydrophilic-hydrophobic conversion function. Due to its stronger dirt-holding capacity, it has the advantage of simultaneously removing suspended solids compared to modification using corrugated plates, metal mesh, and other materials. It also solves the problem that the interface of corrugated plates or metal mesh modified materials is easily damaged by suspended solids, making it difficult to handle emulsions containing suspended solids, thus effectively ensuring the oil removal rate of the system.

[0092] The above description is merely an illustrative embodiment of the present invention and is not intended to limit the scope of the invention. Any equivalent changes and modifications made by those skilled in the art without departing from the concept and principles of the present invention should fall within the scope of protection of the present invention.

Claims

1. A CO2-responsive intelligent antifouling quartz sand filter, characterized in that, Includes a tank body; the tank body is equipped with a separation filter material with adjustable wettability, the separation filter material is a CO2-responsive intelligent anti-fouling quartz sand filter material; the top of the tank body is provided with an exhaust port, and the bottom of the tank body is provided with an air inlet structure, the air inlet structure is used to introduce gas that adjusts the wettability of the separation filter material; The tank body is located above the separating filter media and is provided with an inlet for injecting the mixed liquid. The bottom of the tank body is provided with an outlet and a backwash liquid inlet, and the top of the tank body is provided with a backwash liquid outlet. When filtering the mixture, the separation filter media is oleophilic and hydrophobic. The separation filter media adsorbs and filters oil droplets in the mixture, and the aqueous phase separated by the filtration is discharged through the outlet. During backwashing, CO2 gas is introduced through the air inlet structure to make the separation filter media hydrophilic and oleophobic, and the CO2 gas expands and fluidizes the separation filter media. Backwash liquid is injected through the backwash liquid inlet for backwashing, and the product after backwashing is discharged from the backwash liquid outlet. After backwashing, N2 gas is introduced to make the separation filter media oleophilic and hydrophobic.

2. The CO2-responsive intelligent antifouling quartz sand filter as described in claim 1, characterized in that, The separation filter media includes granular filter media. A modified solution is sprayed onto the surface of the granular filter media to make it CO2 responsive. After the modified solution adheres to the granular filter media, the separation filter media can be transformed from oleophilic and hydrophobic to hydrophilic and oleophobic by introducing CO2 gas, and the separation filter media can be transformed from hydrophilic and oleophobic to oleophilic and hydrophobic by introducing N2 gas.

3. The CO2-responsive intelligent antifouling quartz sand filter as described in claim 2, characterized in that, The particle size of the granular filter media is 0.6-0.8 mm.

4. The CO2-responsive intelligent antifouling quartz sand filter as described in claim 2, characterized in that, The tank body is provided with a flushing port for injecting flushing liquid between the separation filter material and the liquid inlet. The flushing port is opposite to and at the same height as the backwash liquid outlet. During backwashing, backwash liquid is injected into the backwash liquid inlet for backwashing, and then flushing liquid is injected into the flushing port to discharge the backwashed product from the backwash liquid outlet.

5. The CO2-responsive intelligent antifouling quartz sand filter as described in claim 4, characterized in that, The tank is equipped with a liner plate, which has several through holes, and the separation filter material is supported on the liner plate.

6. The CO2-responsive intelligent antifouling quartz sand filter as described in claim 5, characterized in that, The support plate is made of steel plate.

7. The CO2-responsive intelligent antifouling quartz sand filter as described in claim 5, characterized in that, A long-handled filter head is provided below the liner plate, and the two ends of the long-handled filter head are respectively connected to the air inlet structure and the backwash liquid inlet.

8. The CO2-responsive intelligent antifouling quartz sand filter as described in claim 4, characterized in that, The air inlet structure includes a first air inlet and a second air inlet arranged in parallel. The first air inlet is used to introduce CO2 gas, and the second air inlet is used to introduce N2 gas.

9. The CO2-responsive intelligent antifouling quartz sand filter as described in claim 8, characterized in that, A first valve is provided at the liquid inlet, and a second valve is provided at the liquid outlet; a third valve is provided at the first air inlet, a fourth valve is provided at the second air inlet, and a fifth valve is provided at the exhaust outlet; a sixth valve is provided at the backwash liquid inlet, a seventh valve is provided at the backwash liquid outlet, and an eighth valve is provided at the flushing outlet.

10. The CO2-responsive intelligent antifouling quartz sand filter as described in claim 1, characterized in that, The expansion rate of the CO2 gas used to fluidize the separation filter media is 40%-50%.

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