An ozone intermittent reverse catalytic membrane water purifying device and a method for deep water purification using the same

Abstract

An ozone intermittent reverse catalytic membrane water purification device and a method for deep water purification using it are disclosed, belonging to the field of water treatment and environmental protection. The purpose of this invention is to solve the problems in existing membrane treatment systems where small doses of ozone cannot effectively alleviate membrane fouling, and where forward ozone flushing consumes large doses of ozone due to its long path, resulting in unnecessary ozone waste. The ozone intermittent reverse catalytic membrane water purification device includes a wastewater collection module, a wastewater pretreatment module, a catalytic membrane module, an ozone intermittent backwashing module, a purified water detection module, a circulation module, and a purified water collection module. This invention features low economic cost, simple equipment structure and installation, and utilizes green energy to achieve carbon emission reduction. It is suitable for the deep treatment of natural water, reclaimed water, high-quality drinking water, secondary treatment of municipal sewage, and enhanced secondary treatment of municipal sewage effluent. This device removes pollutants such as color, odor, toxic and harmful organic matter, suspended solids (SS), and colloidal substances from water.

Description

Technical Field

[0001] This invention belongs to the field of water treatment and environmental protection, specifically relating to an ozone intermittent reverse catalytic membrane water purification device and a method for deep water purification using it. Background Technology

[0002] With the increasing severity of water scarcity and water pollution, and the growing global demand for drinking water, membrane separation technologies commonly used in water treatment primarily include microfiltration, ultrafiltration, nanofiltration, and reverse osmosis, all driven by pressure difference.

[0003] Catalytic ozone oxidation, as an emerging advanced oxidation technology, is mainly characterized by its superior removal efficiency of pollutants in practical applications. Its mechanism of action can be understood as follows: metal ions, metal oxides in solution, or metal oxides loaded onto a carrier react with ozone, promoting the decomposition of ozone molecules and generating highly oxidizing free radicals, thereby enhancing the ozone oxidation performance.

[0004] Membrane material modification refers to altering the physicochemical properties of filter membranes (such as hydrophilicity / hydrophobicity, pore size, roughness, and charge properties) through specific means and methods. This allows the modified membrane to acquire specific functions, improving its hydrophilicity, retention capacity, and antifouling properties. Pre-coating the membrane surface with manganese oxide accelerates the formation of the biofilm layer during adsorption, thereby enhancing the water purification efficiency of the membrane treatment system. Studies have reported that coating the membrane surface with manganese oxide resulted in a manganese removal rate as high as 95.4% and improved UV resistance. 254 The removal rates of DOC and UVA also improved, reaching 41.94% and 28.54%, respectively. Studies have reported that pre-depositing biochar (BC) on the membrane surface resulted in improved removal rates of DOC and UVA in surface water. 254 The removal rates of organic pollutants such as DOC and UV-sensitive substances were significantly improved. 254 The average removal rates increased from 16.7% and 10% to 34.1% and 39.9%, respectively.

[0005] Membrane treatment systems are susceptible to membrane fouling, which refers to the irreversible degradation of membrane separation performance caused by the adsorption and deposition of microparticles, colloidal particles, or large solute molecules on the membrane surface or within the pores due to physicochemical or mechanical interactions with the membrane. This results in reduced pore size or blockage. Extracellular polymeric substances (EPS) produced by microbial metabolism further increase the filtration resistance of the membrane. These defects limit the widespread application of this technology. Currently, conventional membrane cleaning methods include physical and chemical methods. Physical methods include forward flushing, backflushing, and ultrasonic cleaning, primarily targeting reversible pollutants and inorganic particulate matter. While membrane fouling control and cleaning inevitably affect the structure of the biofilm layer, its formation is a reversible dynamic process, allowing it to rebuild in subsequent filtration processes and continue its function of degrading organic pollutants and filtering. Therefore, membrane fouling control and cleaning have a positive impact on the efficiency of membrane treatment systems.

[0006] Ozone oxidizes the remaining large organic molecules into small organic molecules, ensuring the chemical safety of the water effluent after ultrafiltration. At the same time, it also reduces the amount of organic matter retained by the ultrafiltration membrane, making the membrane pores less prone to clogging and thus reducing membrane fouling caused by organic matter.

[0007] However, membrane treatment systems have several problems that urgently need to be addressed, such as the inability of small doses of ozone to effectively alleviate membrane fouling and the consumption of large doses of ozone due to the long path of forward ozone flushing. Summary of the Invention

[0008] The purpose of this invention is to solve the problems in existing membrane treatment systems where small doses of ozone cannot effectively alleviate membrane fouling and where forward ozone flushing consumes large doses of ozone due to its long path, resulting in unnecessary ozone waste. The invention provides an intermittent reverse catalytic ozone membrane water purification device and a method for deep water purification using it.

[0009] To achieve the above objectives, the present invention provides an ozone intermittent reverse catalytic membrane water purification device and a method for deep water purification using it. The present invention uses a single metal oxide or a bimetallic oxide to prepare a catalytic membrane 3-2. After intermittent reverse rinsing with ozone, ozone in the pores of the catalytic membrane 3-2 is catalyzed by the metal oxide to promote the generation of hydroxyl radicals HO·. The hydroxyl radicals (HO·) destroy the pollutants in the membrane pores, thereby alleviating the irreversible fouling of the membrane pores.

[0010] An ozone intermittent reverse catalytic membrane water purification device includes a wastewater collection module, a wastewater pretreatment module, a catalytic membrane module, an ozone intermittent backwashing module, a purified water detection module, a circulation module, and a purified water collection module.

[0011] The wastewater collection module includes an inlet pipe 1-1, a constant-level water tank 1-2, an ozone exhaust gas destroyer 1-3, a pressure sensor 1-4, and a constant-level water tank outlet valve 1-5.

[0012] The wastewater pretreatment module includes a pretreatment tank 2-1, biochar 2-2, and a cushion layer 2-3; the catalytic membrane module includes a support mesh structure 3-1 and a catalytic membrane 3-2.

[0013] The ozone intermittent backwash module includes an ozone generator 4-1, an ozone backwash valve 4-2, a backwash valve one 4-3, a backwash water tank 4-4, a vent 4-5, an overflow hole 4-6, a backwash water pump 4-7, a backwash main pipe 4-8, a backwash valve two 4-9, and a backwash branch pipe 4-10.

[0014] The purified water testing module includes a purified water outlet valve 5-1, a water quality tester 5-2, and a purified water outlet main pipe 5-3;

[0015] The circulation module includes a first return valve 6-1, a first return pipe 6-2, an overflow pipe 6-3, an overflow valve 6-4, a second return valve 6-5, a second return pipe 6-6, a return water pump 6-7, and a circulating water tank 6-8.

[0016] The purified water collection module includes a vent 7-1, a purified water collection tank 7-2, and a purified water outlet valve 7-3;

[0017] The wastewater collection module is equipped with an ozone exhaust gas destroyer 1-3 at the top of the constant water tank 1-2, a pressure sensor 1-4 and a constant water tank outlet valve 1-5 at the bottom, and an inlet pipe 1-1 connected to the upper part of the constant water tank 1-2.

[0018] The biochar 2-2 and the bedding layer 2-3 are arranged in the pretreatment tank 2-1. The biochar 2-2 is the filter material of the wastewater pretreatment module. Below the filter material is the bedding layer 2-3. Below the bedding layer 2-3 is the support mesh structure 3-1 in the catalytic membrane module. The support mesh structure 3-1 is divided into upper and lower parts. The catalytic membrane 3-2 is fixed in the middle. The bottom layer is the backwashing main pipe 4-8 and backwashing branch pipe 4-10 in the ozone intermittent backwashing module. A constant level water tank 1-2 is provided above the wastewater pretreatment module.

[0019] In the ozone intermittent backwash module, the ozone backwash valve 4-2 is connected to the ozone generator 4-1 at the front end; the backwash main pipe 4-8 is connected to the backwash water pump 4-7, and there are several backwash branch pipes 4-10 on the backwash main pipe 4-8 located at the bottom inside the pretreatment tank 2-1. The backwash main pipe 4-8 located between the pretreatment tank 2-1 and the backwash water pump 4-7 is equipped with a backwash valve 4-9.

[0020] In the ozone intermittent backwash module, the backwash water pump 4-7 is connected to the backwash water tank 4-4 through a pipeline. The backwash water tank 4-4 is provided with a vent 4-5 at the top and an overflow hole 4-6 at the top.

[0021] The ozone intermittent backwash module is equipped with a water quality detector 5-2 at its outlet and a purified water outlet valve 5-1 is connected to the inlet of the water quality detector 5-2; the purified water outlet main pipe 5-3 is connected to the backwash water tank 4-4 through the backwash pipeline, and a backwash valve 4-3 is provided on the backwash pipeline.

[0022] In the circulation module, the circulating water tank 6-8 is connected to the pretreatment tank 2-1 of the wastewater pretreatment module and the constant-level water tank 1-2 of the wastewater collection module through return pipe 1 6-2 and return pipe 2 6-6 respectively. The circulating water tank 6-8 and the constant-level water tank 1-2 form a return flow, and a return water pump 6-7 is provided on the return pipe at the bottom of the circulating water tank 6-8; a return valve 1 6-1 is provided on the return pipe 6-2; and a return valve 2 6-5 is provided on the return pipe 2 6-6.

[0023] The constant-level water tank 1-2 is connected to the pretreatment tank 2-1 through the constant-level water tank outlet pipe. The bottom end of the pretreatment tank 2-1 is connected to the purified water collection tank 7-2 through the purified water outlet main pipe 5-3. The purified water collection tank 7-2 is connected to the purified water outlet valve 7-3. The upper end of the circulating water tank 6-8 is connected to the constant-level water tank 1-2 through the overflow pipe 6-3. An overflow valve 6-4 is provided on the overflow pipe 6-3.

[0024] A deep water purification method using an ozone intermittent reverse catalytic membrane water purification device is specifically completed according to the following steps:

[0025] 1. The water to be treated enters the constant-level water tank 1-2 through the inlet pipe 1-1. Close the return valve 6-1, ozone backwash valve 4-2, and backwash valve 4-9, and open all other valves. The water to be treated enters the wastewater pretreatment module and catalytic membrane module through the outlet valve 1-5 of the constant-level water tank for treatment. After running for a period of time, if water overflows from the overflow hole 4-6 of the backwash water tank 4-4, close the backwash valve 4-3. If the water level in the constant-level water tank 1-2 exceeds the water level in the overflow hole 4-6, the pressure sensor 1-4 will send a signal to make the return water pump 6-7 work.

[0026] 2. Open ozone backwash valve 4-2, return valve 6-1, and ozone tail gas destroyer 1-3 to stop water intake. Close purified water outlet valve 5-1, backwash valve 4-3, backwash valve 4-9, and backwash water pump 4-7. Then turn on ozone generator 4-1 for ozone oxygen backwash. When performing water backwash, close ozone generator 4-1 and ozone backwash valve 4-2, and open backwash valve 4-9 and backwash water pump 4-7. The backwash water will pass through pretreatment tank 2-1 and return valve 6-1 into circulating water tank 6-8. When the backwash ends, close backwash water pump 4-7, backwash valve 4-9, ozone backwash valve 4-2, ozone generator 4-1, return valve 6-1, and ozone tail gas destroyer 1-3, and open purified water outlet valve 5-1 and backwash valve 4-3 to obtain treated drinking water, which flows into purified water collection tank 7-2.

[0027] The ozone generator 4-1 has an outlet concentration of 2 mg / L to 10 mg / L, and each time it discharges water in the forward direction for 20 minutes, followed by a reverse ozone rinse for 5 to 10 minutes.

[0028] The catalytic membrane 3-2 is an external type: operating pressure ≤ 0.2 MPa, membrane flux preferably 40~70 L / (m²). 2 •h); The catalytic membrane 3-2 is an immersed type: operating pressure ≤0.05MPa, membrane flux preferably 30~50L / (m 2 ·h).

[0029] The present invention has the following beneficial effects:

[0030] I. This invention solves the problems in existing membrane treatment systems where small doses of ozone cannot effectively alleviate membrane fouling, and where forward ozone flushing consumes large doses of ozone due to its long path, resulting in unnecessary ozone waste and high costs; the catalytic membrane 3-2 prepared by this invention has a contact angle that is 10° lower than that of the original membrane, and its hydrophilicity is greatly improved.

[0031] 2. After ozone backwashing, catalysis is carried out on the surface of the catalytic membrane 3-2, which damages the pollutants in the membrane pores and destroys the irreversible fouling of the membrane.

[0032] 3. A small amount of residual ozone enters the surface of the catalytic membrane 3-2, and comes into contact with the biofilm attached to the membrane surface and the water to form dissolved oxygen that is conducive to the growth of biofilm, thereby increasing the activity of aerobic microorganisms and effectively removing a variety of pollutants from the wastewater.

[0033] IV. This invention features low economic cost, simple equipment structure and installation, and utilizes green energy to achieve carbon emission reduction. It is suitable for the advanced treatment of natural water, reclaimed water, high-quality drinking water, secondary urban sewage treatment, and enhanced secondary urban sewage treatment effluent. This device removes pollutants such as color, odor, toxic and harmful organic matter, suspended solids (SS), and colloidal substances from water; CODC... r The removal rate is approximately 5-30%, the turbidity is <0.2 NTU, and the water recovery rate is ≥90%. It has a significant effect on removing color, odor, and toxic and harmful organic matter containing unsaturated bonds. The effluent color is generally less than 10 degrees. It can effectively remove odor and has the effect of reducing biological toxicity.

[0034] V. This invention can generate ozone on-site, is simple to operate, and can replace conventional sedimentation-filtration processes and conventional ozone catalytic membrane treatment processes. It has the ability to efficiently remove color, odor, toxic and harmful organic matter, suspended solids and colloidal substances, and the effluent water quality is better than that of conventional media filtration. It has a small footprint and a high degree of automation. Due to the intermittent in-situ reverse ozone catalysis, it saves costs compared to forward in-situ ozone catalysis. When treating the same pollutants, intermittent in-situ reverse ozone catalysis saves more than 35% of ozone compared to forward in-situ ozone catalysis. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of an ozone intermittent reverse catalytic membrane water purification device.

[0036] Figure 2 for Figure 1 A partial view of the catalytic membrane module in the image;

[0037] Figure 3 Here is a photograph of the catalytic membrane prepared in Example 2;

[0038] Figure 4 This is a SEM image of the catalytic membrane prepared in Example 2. Detailed Implementation

[0039] Specific Implementation Method 1: This implementation method provides an ozone intermittent reverse catalytic membrane water purification device, which includes a wastewater collection module, a wastewater pretreatment module, a catalytic membrane module, an ozone intermittent backwashing module, a purified water detection module, a circulation module, and a purified water collection module.

[0040] The wastewater collection module includes an inlet pipe 1-1, a constant-level water tank 1-2, an ozone exhaust gas destroyer 1-3, a pressure sensor 1-4, and a constant-level water tank outlet valve 1-5.

[0041] The wastewater pretreatment module includes a pretreatment tank 2-1, biochar 2-2, and a cushion layer 2-3; the catalytic membrane module includes a support mesh structure 3-1 and a catalytic membrane 3-2.

[0042] The ozone intermittent backwash module includes an ozone generator 4-1, an ozone backwash valve 4-2, a backwash valve one 4-3, a backwash water tank 4-4, a vent 4-5, an overflow hole 4-6, a backwash water pump 4-7, a backwash main pipe 4-8, a backwash valve two 4-9, and a backwash branch pipe 4-10.

[0043] The purified water testing module includes a purified water outlet valve 5-1, a water quality tester 5-2, and a purified water outlet main pipe 5-3;

[0044] The circulation module includes a first return valve 6-1, a first return pipe 6-2, an overflow pipe 6-3, an overflow valve 6-4, a second return valve 6-5, a second return pipe 6-6, a return water pump 6-7, and a circulating water tank 6-8.

[0045] The purified water collection module includes a vent 7-1, a purified water collection tank 7-2, and a purified water outlet valve 7-3;

[0046] The wastewater collection module is equipped with an ozone exhaust gas destroyer 1-3 at the top of the constant water tank 1-2, a pressure sensor 1-4 and a constant water tank outlet valve 1-5 at the bottom, and an inlet pipe 1-1 connected to the upper part of the constant water tank 1-2.

[0047] The biochar 2-2 and the bedding layer 2-3 are arranged in the pretreatment tank 2-1. The biochar 2-2 is the filter material of the wastewater pretreatment module. Below the filter material is the bedding layer 2-3. Below the bedding layer 2-3 is the support mesh structure 3-1 in the catalytic membrane module. The support mesh structure 3-1 is divided into upper and lower parts. The catalytic membrane 3-2 is fixed in the middle. The bottom layer is the backwashing main pipe 4-8 and backwashing branch pipe 4-10 in the ozone intermittent backwashing module. A constant level water tank 1-2 is provided above the wastewater pretreatment module.

[0048] In the ozone intermittent backwash module, the ozone backwash valve 4-2 is connected to the ozone generator 4-1 at the front end; the backwash main pipe 4-8 is connected to the backwash water pump 4-7, and there are several backwash branch pipes 4-10 on the backwash main pipe 4-8 located at the bottom inside the pretreatment tank 2-1. The backwash main pipe 4-8 located between the pretreatment tank 2-1 and the backwash water pump 4-7 is equipped with a backwash valve 4-9.

[0049] In the ozone intermittent backwash module, the backwash water pump 4-7 is connected to the backwash water tank 4-4 through a pipeline. The backwash water tank 4-4 is provided with a vent 4-5 at the top and an overflow hole 4-6 at the top.

[0050] The ozone intermittent backwash module is equipped with a water quality detector 5-2 at its outlet and a purified water outlet valve 5-1 is connected to the inlet of the water quality detector 5-2; the purified water outlet main pipe 5-3 is connected to the backwash water tank 4-4 through the backwash pipeline, and a backwash valve 4-3 is provided on the backwash pipeline.

[0051] In the circulation module, the circulating water tank 6-8 is connected to the pretreatment tank 2-1 of the wastewater pretreatment module and the constant-level water tank 1-2 of the wastewater collection module through return pipe 1 6-2 and return pipe 2 6-6 respectively. The circulating water tank 6-8 and the constant-level water tank 1-2 form a return flow, and a return water pump 6-7 is provided on the return pipe at the bottom of the circulating water tank 6-8; a return valve 1 6-1 is provided on the return pipe 6-2; and a return valve 2 6-5 is provided on the return pipe 2 6-6.

[0052] The constant-level water tank 1-2 is connected to the pretreatment tank 2-1 through the constant-level water tank outlet pipe. The bottom end of the pretreatment tank 2-1 is connected to the purified water collection tank 7-2 through the purified water outlet main pipe 5-3. The purified water collection tank 7-2 is connected to the purified water outlet valve 7-3. The upper end of the circulating water tank 6-8 is connected to the constant-level water tank 1-2 through the overflow pipe 6-3. An overflow valve 6-4 is provided on the overflow pipe 6-3.

[0053] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that the preparation method of the catalyst membrane 3-2 is specifically carried out according to the following steps:

[0054] 1. Disperse single-metal oxide particles or bimetal oxide particles at a concentration of 10. -4 ~10 -3 In a mol / L KNO3 solution or NaNO3 solution, a metal oxide suspension is obtained;

[0055] 2. Stir the metal oxide suspension magnetically for a period of time to obtain the magnetically stirred metal oxide suspension.

[0056] 3. Place the original membrane into the metal oxide suspension after magnetic stirring and allow it to settle naturally for 6 to 8 hours to obtain the original membrane containing metal oxides.

[0057] 4. The original membrane containing metal oxides is vacuum dried, then calcined, and finally naturally cooled to room temperature to obtain catalytic membrane 3-2. Other steps are the same as in specific implementation method one.

[0058] Specific Implementation Method Three: This implementation method differs from Specific Implementation Method One or Two in that: the single metal oxide mentioned in step one is a transition metal element oxide such as MnO2, MnO, Mn2O3, CoO, Fe2O3, or Fe3O4; the bimetallic oxide mentioned is a copper-nickel bimetallic oxide CuNiO, Cu... 0.2 MnO xAlternatively, a Mn-Fe bimetallic oxide may be used; when the monometallic oxide mentioned in step one is MnO2, the calcination process in step four is: calcination at 850℃~1000℃ for 110min~160min. Other steps are the same as in specific implementation method one or two.

[0059] Specific Implementation Method Four: The difference between this implementation method and Specific Implementation Methods One to Three is that the mass and concentration of the single metal oxide particles mentioned in step one are 10. -4 ~10 -3 The volume ratio of mol / L KNO3 solution or NaNO3 solution is (0.2g~0.8g):(1000mL~2000mL); the mass and concentration of the bimetallic oxide particles are 10. -4 ~10 -3 The volume ratio of mol / L KNO3 solution or NaNO3 solution is (0.2g~0.8g):(1000mL~2000mL). Other steps are the same as in specific embodiments one to three.

[0060] Specific Implementation Method Five: This implementation method differs from Specific Implementation Methods One to Four in that the magnetic stirring described in step two is performed at a speed of 300 r / min to 600 r / min for 12 to 15 hours. The other steps are the same as in Specific Implementation Methods One to Four.

[0061] Specific Implementation Method Six: This implementation method differs from Specific Implementation Methods One through Five in that: the original membrane mentioned in step three is an Al2O3 ceramic membrane, a TiO2 ceramic membrane, a PVDF membrane, or a cellulose acetate membrane; the loading of metal oxides in the original membrane containing metal oxides mentioned in step three is 20 mg / cm³. 2 ~80mg / cm 2 The other steps are the same as those in implementation methods one through five.

[0062] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Methods One to Six in that the vacuum drying temperature in step four is 45℃~100℃, and the vacuum drying time is 0.5h~2h. The other steps are the same as in Specific Implementation Methods One to Six.

[0063] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Methods One to Seven in that the valves and pumps in the ozone intermittent reverse catalytic membrane water purification device are automatically controlled by a PLC control system. The other steps are the same as in Specific Implementation Methods One to Seven.

[0064] Specific Implementation Method Nine: This implementation method utilizes an ozone intermittent reverse catalytic membrane water purification device for deep water purification, specifically completed according to the following steps:

[0065] 1. The water to be treated enters the constant-level water tank 1-2 through the inlet pipe 1-1. Close the return valve 6-1, ozone backwash valve 4-2, and backwash valve 4-9, and open all other valves. The water to be treated enters the wastewater pretreatment module and catalytic membrane module through the outlet valve 1-5 of the constant-level water tank for treatment. After running for a period of time, if water overflows from the overflow hole 4-6 of the backwash water tank 4-4, close the backwash valve 4-3. If the water level in the constant-level water tank 1-2 exceeds the water level in the overflow hole 4-6, the pressure sensor 1-4 will send a signal to make the return water pump 6-7 work.

[0066] 2. Open ozone backwash valve 4-2, return valve 6-1, and ozone tail gas destroyer 1-3 to stop water intake. Close purified water outlet valve 5-1, backwash valve 4-3, backwash valve 4-9, and backwash water pump 4-7. Then turn on ozone generator 4-1 for ozone oxygen backwash. When performing water backwash, close ozone generator 4-1 and ozone backwash valve 4-2, and open backwash valve 4-9 and backwash water pump 4-7. The backwash water will pass through pretreatment tank 2-1 and return valve 6-1 into circulating water tank 6-8. When the backwash ends, close backwash water pump 4-7, backwash valve 4-9, ozone backwash valve 4-2, ozone generator 4-1, return valve 6-1, and ozone tail gas destroyer 1-3, and open purified water outlet valve 5-1 and backwash valve 4-3 to obtain treated drinking water, which flows into purified water collection tank 7-2.

[0067] The ozone generator 4-1 has an outlet concentration of 2 mg / L to 10 mg / L, and each time it discharges water in the forward direction for 20 minutes, followed by a reverse ozone rinse for 5 to 10 minutes.

[0068] The catalytic membrane 3-2 is an external type: operating pressure ≤ 0.2 MPa, membrane flux preferably 40~70 L / (m²). 2 •h); The catalytic membrane 3-2 is an immersed type: operating pressure ≤0.05MPa, membrane flux preferably 30~50L / (m 2 ·h).

[0069] Specific Implementation Method Ten: This implementation method differs from Specific Implementation Methods One to Nine in that: the total hardness of the water to be treated is ≤450mg / L and the TDS is ≤1000mg / L; the total hardness of the treated drinking water is ≤120mg / L and the TDS is ≤20mg / L. Other steps are the same as in Specific Implementation Methods One to Nine.

[0070] The beneficial effects of the present invention are verified using the following embodiments:

[0071] Example 1: An ozone intermittent reverse catalytic membrane water purification device includes a wastewater collection module, a wastewater pretreatment module, a catalytic membrane module, an ozone intermittent backwashing module, a purified water detection module, a circulation module, and a purified water collection module;

[0072] The wastewater collection module includes an inlet pipe 1-1, a constant-level water tank 1-2, an ozone exhaust gas destroyer 1-3, a pressure sensor 1-4, and a constant-level water tank outlet valve 1-5.

[0073] The wastewater pretreatment module includes a pretreatment tank 2-1, biochar 2-2, and a cushion layer 2-3; the catalytic membrane module includes a support mesh structure 3-1 and a catalytic membrane 3-2.

[0074] The ozone intermittent backwash module includes an ozone generator 4-1, an ozone backwash valve 4-2, a backwash valve one 4-3, a backwash water tank 4-4, a vent 4-5, an overflow hole 4-6, a backwash water pump 4-7, a backwash main pipe 4-8, a backwash valve two 4-9, and a backwash branch pipe 4-10.

[0075] The purified water testing module includes a purified water outlet valve 5-1, a water quality tester 5-2, and a purified water outlet main pipe 5-3;

[0076] The circulation module includes a first return valve 6-1, a first return pipe 6-2, an overflow pipe 6-3, an overflow valve 6-4, a second return valve 6-5, a second return pipe 6-6, a return water pump 6-7, and a circulating water tank 6-8.

[0077] The purified water collection module includes a vent 7-1, a purified water collection tank 7-2, and a purified water outlet valve 7-3;

[0078] The wastewater collection module is equipped with an ozone exhaust gas destroyer 1-3 at the top of the constant water tank 1-2, a pressure sensor 1-4 and a constant water tank outlet valve 1-5 at the bottom, and an inlet pipe 1-1 connected to the upper part of the constant water tank 1-2.

[0079] The biochar 2-2 and the bedding layer 2-3 are arranged in the pretreatment tank 2-1. The biochar 2-2 is the filter material of the wastewater pretreatment module. Below the filter material is the bedding layer 2-3. Below the bedding layer 2-3 is the support mesh structure 3-1 in the catalytic membrane module. The support mesh structure 3-1 is divided into upper and lower parts. The catalytic membrane 3-2 is fixed in the middle. The bottom layer is the backwashing main pipe 4-8 and backwashing branch pipe 4-10 in the ozone intermittent backwashing module. A constant level water tank 1-2 is provided above the wastewater pretreatment module.

[0080] In the ozone intermittent backwash module, the ozone backwash valve 4-2 is connected to the ozone generator 4-1 at the front end; the backwash main pipe 4-8 is connected to the backwash water pump 4-7, and there are several backwash branch pipes 4-10 on the backwash main pipe 4-8 located at the bottom inside the pretreatment tank 2-1. The backwash main pipe 4-8 located between the pretreatment tank 2-1 and the backwash water pump 4-7 is equipped with a backwash valve 4-9.

[0081] In the ozone intermittent backwash module, the backwash water pump 4-7 is connected to the backwash water tank 4-4 through a pipeline. The backwash water tank 4-4 is provided with a vent 4-5 at the top and an overflow hole 4-6 at the top.

[0082] The ozone intermittent backwash module is equipped with a water quality detector 5-2 at its outlet and a purified water outlet valve 5-1 is connected to the inlet of the water quality detector 5-2; the purified water outlet main pipe 5-3 is connected to the backwash water tank 4-4 through the backwash pipeline, and a backwash valve 4-3 is provided on the backwash pipeline.

[0083] In the circulation module, the circulating water tank 6-8 is connected to the pretreatment tank 2-1 of the wastewater pretreatment module and the constant-level water tank 1-2 of the wastewater collection module through return pipe 1 6-2 and return pipe 2 6-6 respectively. The circulating water tank 6-8 and the constant-level water tank 1-2 form a return flow, and a return water pump 6-7 is provided on the return pipe at the bottom of the circulating water tank 6-8; a return valve 1 6-1 is provided on the return pipe 6-2; and a return valve 2 6-5 is provided on the return pipe 2 6-6.

[0084] The constant-level water tank 1-2 is connected to the pretreatment tank 2-1 through the constant-level water tank outlet pipe. The bottom end of the pretreatment tank 2-1 is connected to the purified water collection tank 7-2 through the purified water outlet main pipe 5-3. The purified water collection tank 7-2 is connected to the purified water outlet valve 7-3. The upper end of the circulating water tank 6-8 is connected to the constant-level water tank 1-2 through the overflow pipe 6-3. An overflow valve 6-4 is provided on the overflow pipe 6-3.

[0085] In the ozone intermittent reverse catalytic membrane water purification device, the valves and pumps are automatically controlled by a PLC control system.

[0086] Example 2: The preparation method of the catalytic membrane 3-2 described in Example 1 is carried out according to the following steps:

[0087] I. The single metal oxide particles are dispersed at a concentration of 10. -3 In a mol / L KNO3 solution, a suspension of metal oxides was obtained;

[0088] The single metal oxide mentioned in step one is MnO2;

[0089] The mass and concentration of the single metal oxide particles mentioned in step one are 10.-3 The volume ratio of mol / L KNO3 solution is 0.5g:1000mL;

[0090] 2. The metal oxide suspension was magnetically stirred at 500 r / min for 12 h to obtain the magnetically stirred metal oxide suspension.

[0091] 3. Place the original membrane into the metal oxide suspension after magnetic stirring and allow it to settle naturally for 7 hours to obtain the original membrane containing metal oxides.

[0092] The original membrane mentioned in step three is an Al2O3 ceramic membrane; the loading of metal oxides in the original membrane containing metal oxides mentioned in step three is 50 mg / cm³. 2 ;

[0093] 4. The original membrane containing metal oxides was vacuum dried at 100℃ for 1 hour, then calcined at 900℃ for 150 minutes, and finally naturally cooled to room temperature to obtain the catalytic membrane 3-2.

[0094] Figure 3 Here is a photograph of the catalytic membrane prepared in Example 2;

[0095] Figure 4 This is a SEM image of the catalytic membrane prepared in Example 2.

[0096] from Figure 4 It can be seen that this is the microstructure of the catalytic film surface.

[0097] Example 3: The deep water purification method using the ozone intermittent reverse catalytic membrane water purification device described in Example 1 is specifically completed according to the following steps:

[0098] 1. The water to be treated enters the constant-level water tank 1-2 through the inlet pipe 1-1. Close the return valve 6-1, ozone backwash valve 4-2, and backwash valve 4-9, and open all other valves. The water to be treated enters the wastewater pretreatment module and catalytic membrane module through the outlet valve 1-5 of the constant-level water tank for treatment. After running for a period of time, if water overflows from the overflow hole 4-6 of the backwash water tank 4-4, close the backwash valve 4-3. If the water level in the constant-level water tank 1-2 exceeds the water level in the overflow hole 4-6, the pressure sensor 1-4 will send a signal to make the return water pump 6-7 work.

[0099] 2. Open ozone backwash valve 4-2, return valve 6-1, and ozone tail gas destroyer 1-3 to stop water intake. Close purified water outlet valve 5-1, backwash valve 4-3, backwash valve 4-9, and backwash water pump 4-7. Then turn on ozone generator 4-1 for ozone oxygen backwash. When performing water backwash, close ozone generator 4-1 and ozone backwash valve 4-2, and open backwash valve 4-9 and backwash water pump 4-7. The backwash water will pass through pretreatment tank 2-1 and return valve 6-1 into circulating water tank 6-8. When the backwash ends, close backwash water pump 4-7, backwash valve 4-9, ozone backwash valve 4-2, ozone generator 4-1, return valve 6-1, and ozone tail gas destroyer 1-3, and open purified water outlet valve 5-1 and backwash valve 4-3 to obtain treated drinking water, which flows into purified water collection tank 7-2.

[0100] The ozone generator 4-1 has an outlet concentration of 5 mg / L, and each time it discharges water in the forward direction for 20 minutes, followed by a reverse ozone rinse for 5 minutes.

[0101] The catalytic membrane 3-2 is an immersed type: operating pressure ≤ 0.05 MPa, membrane flux preferably 30-50 L / (m²). 2 ·h);

[0102] The total hardness of the water to be treated is ≤450mg / L and the TDS is ≤1000mg / L; the total hardness of the treated drinking water is ≤120mg / L and the TDS is ≤20mg / L.

Claims

1. An intermittent reverse catalytic membrane water purifying device of ozone, characterized in that An ozone intermittent reverse catalytic membrane water purification device includes a wastewater collection module, a wastewater pretreatment module, a catalytic membrane module, an ozone intermittent backwashing module, a purified water detection module, a circulation module, and a purified water collection module. The wastewater collection module includes an inlet pipe (1-1), a constant-level water tank (1-2), an ozone exhaust gas destroyer (1-3), a pressure sensor (1-4), and a constant-level water tank outlet valve (1-5). The wastewater pretreatment module includes a pretreatment tank (2-1), biochar (2-2), and a bedding layer (2-3). The catalytic membrane module includes a support mesh structure (3-1) and a catalytic membrane (3-2). The ozone intermittent backwash module includes an ozone generator (4-1), an ozone backwash valve (4-2), a backwash valve one (4-3), a backwash water tank (4-4), a vent, an overflow hole (4-6), a backwash water pump (4-7), a backwash main pipe (4-8), a backwash valve two (4-9), and a backwash branch pipe (4-10). The purified water testing module includes a purified water outlet valve (5-1), a water quality tester (5-2), and a purified water outlet main pipe (5-3). The circulation module includes a first return valve (6-1), a first return pipe (6-2), an overflow pipe (6-3), an overflow valve (6-4), a second return valve (6-5), a second return pipe (6-6), a return water pump (6-7), and a circulating water tank (6-8). The purified water collection module includes a vent, a purified water collection tank (7-2), and a purified water outlet valve (7-3). The wastewater collection module has an ozone exhaust gas destroyer (1-3) at the top of the constant water tank (1-2), a pressure sensor (1-4) and a constant water tank outlet valve (1-5) at the bottom, and an inlet pipe (1-1) connected to the upper part of the constant water tank (1-2). The biochar (2-2) and the bedding layer (2-3) are arranged in the pretreatment tank (2-1). The biochar (2-2) is the filter material of the wastewater pretreatment module. Below the filter material is the bedding layer (2-3). Below the bedding layer (2-3) is the support mesh structure (3-1) in the catalytic membrane module. The support mesh structure (3-1) is divided into upper and lower parts. The catalytic membrane (3-2) is fixed in the middle. The bottom layer is the backwashing main pipe (4-8) and backwashing branch pipe (4-10) in the ozone intermittent backwashing module. A constant-level water tank (1-2) is provided above the wastewater pretreatment module. The preparation method of the catalytic membrane (3-2) is specifically carried out according to the following steps:

1. Disperse single-metal oxide particles or bimetal oxide particles in a solution with a concentration of 10... -4 ~10 -3 In a mol / L KNO3 solution or NaNO3 solution, a metal oxide suspension is obtained; 2. Stir the metal oxide suspension magnetically for a period of time to obtain the magnetically stirred metal oxide suspension.

3. Place the original membrane into the metal oxide suspension after magnetic stirring and allow it to settle naturally for 6 to 8 hours to obtain the original membrane containing metal oxides. IV. The original membrane containing metal oxides is vacuum dried, then calcined, and finally naturally cooled to room temperature to obtain the catalytic membrane (3-2). In the ozone intermittent backwash module, the ozone backwash valve (4-2) is connected to the ozone generator (4-1) at the front end; the backwash main pipe (4-8) is connected to the backwash water pump (4-7), and there are several backwash branch pipes (4-10) on the backwash main pipe (4-8) located at the bottom inside the pretreatment tank (2-1). A backwash valve two (4-9) is provided on the backwash main pipe (4-8) located between the pretreatment tank (2-1) and the backwash water pump (4-7). In the ozone intermittent backwash module, the backwash water pump (4-7) is connected to the backwash water tank (4-4) through a pipeline. The backwash water tank (4-4) has a vent at the top and an overflow hole (4-6) at the top. The ozone intermittent backwash module is equipped with a water quality detector (5-2) at its outlet and a purified water outlet valve (5-1) is connected to the inlet of the water quality detector (5-2); the purified water outlet main pipe (5-3) is connected to the backwash water tank (4-4) through the backwash pipeline, and a backwash valve (4-3) is provided on the backwash pipeline. In the circulation module, the circulating water tank (6-8) is connected to the pretreatment tank (2-1) of the wastewater pretreatment module and the constant-level water tank (1-2) of the wastewater collection module through return pipe one (6-2) and return pipe two (6-6), respectively. The circulating water tank (6-8) and the constant-level water tank (1-2) form a backflow. A return water pump (6-7) is provided on the return pipe two (6-6) at the bottom of the circulating water tank (6-8). A return valve one (6-1) is provided on the return pipe one (6-2). A return valve two (6-5) is provided on the return pipe two (6-6). The constant-level water tank (1-2) is connected to the pretreatment tank (2-1) through the constant-level water tank outlet pipe. The bottom end of the pretreatment tank (2-1) is connected to the purified water collection tank (7-2) through the purified water outlet main pipe (5-3). The purified water collection tank (7-2) is connected to the purified water outlet valve (7-3). The upper end of the circulating water tank (6-8) is connected to the constant-level water tank (1-2) through the overflow pipe (6-3). An overflow valve (6-4) is provided on the overflow pipe (6-3).

2. The ozone intermittent reverse catalytic membrane water purifier according to claim 1, characterized in that The single metal oxide mentioned in step one is a transition metal oxide such as MnO2, MnO, Mn2O3, CoO, Fe2O3, or Fe3O4; the bimetallic oxide is a copper-nickel bimetallic oxide such as CuNiO or Cu 0.2 MnO x Or Mn-Fe bimetallic oxide; when the monometallic oxide mentioned in step one is MnO2, the calcination process in step four is: calcination at 850℃~1000℃ for 110min~160min.

3. The ozone intermittent reverse catalytic membrane water purifier according to claim 1, characterized in that The mass and concentration of the single metal oxide particles mentioned in step one are 10. -4 ~10 -3 The volume ratio of mol / L KNO3 solution or NaNO3 solution is (0.2g~0.8g):(1000mL~2000mL); the mass and concentration of the bimetallic oxide particles are 10. -4 ~10 - 3 The volume ratio of mol / L KNO3 solution or NaNO3 solution is (0.2g~0.8g):(1000mL~2000mL).

4. The ozone intermittent reverse catalytic membrane water purification device according to claim 1, characterized in that... The magnetic stirring described in step two involves stirring at a speed of 300 r / min to 600 r / min for 12 to 15 hours.

5. The ozone intermittent reverse catalytic membrane water purifier according to claim 1, characterized in that The original membrane mentioned in step three is an Al2O3 ceramic membrane, a TiO2 ceramic membrane, a PVDF membrane, or a cellulose acetate membrane; the metal oxide loading in the original membrane containing metal oxides mentioned in step three is 20 mg / cm³. 2 ~80mg / cm 2 .

6. The ozone intermittent reverse catalytic membrane water purifier according to claim 1, characterized in that The vacuum drying temperature in step four is 45℃~100℃, and the vacuum drying time is 0.5h~2h.

7. The ozone intermittent reverse catalytic membrane water purifier according to claim 1, characterized in that In the ozone intermittent reverse catalytic membrane water purification device, the valves and pumps are automatically controlled by a PLC control system.

8. The method for advanced water purification by using the ozone intermittent reverse catalytic membrane water purification device according to claim 1, characterized in that Specifically, it is done by following these steps:

1. The water to be treated enters the constant-level water tank (1-2) through the inlet pipe (1-1), and the return valve 1 (6-1), ozone backwash valve (4-2), and backwash valve 2 (4-9) are closed, while all other valves are opened; the water to be treated enters the wastewater pretreatment module and catalytic membrane module for treatment through the outlet valve (1-5) of the constant-level water tank; after running for a period of time, if water overflows from the overflow hole (4-6) of the backwash water tank (4-4), the backwash valve 1 (4-3) is closed; if the water level in the constant-level water tank (1-2) exceeds the water level in the overflow pipe (6-3), the pressure sensor (1-4) will send a signal to make the return water pump (6-7) work; 2. Open the ozone backwash valve (4-2), return valve one (6-1), and ozone exhaust gas destroyer (1-3), stop the water inlet, and close the purified water outlet valve one (5-1), backwash valve one (4-3), backwash valve two (4-9), and backwash water pump (4-7). Then turn on the ozone generator (4-1) to perform ozone oxygen backwash; when performing water backwash, close the ozone generator (4-1) and ozone backwash valve (4-2), and open backwash valve two (4-9) and backwash water pump (4-7). (4-7) The backwash water will pass through the pretreatment tank (2-1) and return valve one (6-1) into the circulating water tank (6-8); when the backwashing ends, the backwash water pump (4-7), backwash valve two (4-9), ozone backwash valve (4-2), ozone generator (4-1), return valve one (6-1), and ozone tail gas destroyer (1-3) are turned off, and the purified water outlet valve one (5-1) and backwash valve one (4-3) are turned on to obtain the treated drinking water, which flows into the purified water collection tank (7-2); The ozone generator (4-1) has an outlet concentration of 2mg / L~10mg / L, and each time it discharges water in the forward direction for 20 minutes, followed by a reverse ozone rinse for 5 minutes~10 minutes. The catalytic membrane (3-2) is an external type: operating pressure ≤ 0.2 MPa, membrane flux preferably 40~70 L / (m²). 2 •h); The catalytic membrane (3-2) is an immersed type: operating pressure ≤0.05MPa, membrane flux preferably 30~50 L / (m 2 ·h).

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