Algae-containing water source treatment method and system based on high-gradient magnetic separation

Abstract

The application discloses a kind of high-gradient magnetic separation-based algal-containing water source water treatment method and system, it is especially suitable for town water supply plant pre-oxidation-coagulation treatment algal-containing lake reservoir water source water.The treatment system includes photocatalytic reaction pool, mixing pool, flocculation pool, sedimentation tank, sludge storage tank, high-gradient magnetic cyclone separation device in series, purification tank, through the high-gradient magnetic cyclone separation device, magnetic photocatalyst and flocculant combined with it can be separated, recovered, and in purification tank, reactivated backflow to photocatalytic reaction pool, can make the dosage of magnetic photocatalyst and flocculant respectively reduce 35~50, 30~40 percentage points, and significantly improve flocculation effect, guarantee high algal period water supply safety.

Description

Technical Field

[0001] The present invention relates to the technical field of water treatment, in particular to the technical field of photocatalytic water treatment using a magnetic photocatalyst. Background Art

[0002] Algal pollution caused by algal blooms not only damages the aquatic environment, reducing water clarity and dissolved oxygen concentration, causing odor and the death of aquatic organisms, diminishing water sensory properties, and disrupting the aquatic ecosystem, but also has numerous negative impacts on water treatment processes, such as increased coagulant consumption, loosening floc structure and density, impairing sedimentation efficiency, increasing filter load, causing severe membrane fouling, and generating disinfection byproducts. Therefore, the effective prevention and control of algal pollution is a key issue in water environmental management.

[0003] Traditional treatment methods for algae-containing water can be categorized as chemical, physical, and biological. Chemical methods primarily utilize chemicals to remove algae from water. While they offer the advantage of rapid algae removal, they can also lead to the development of microbial resistance and secondary pollution and toxic side effects, resulting in certain limitations. Physical methods are the core of most water treatment processes and are often combined with chemical methods. Traditional physical treatment technologies for algae-containing water include direct filtration, flotation, adsorption, microelectrolysis, ultrasonic disruption, and ultraviolet irradiation. While physical methods do not cause secondary pollution, they can lead to algal cell disruption and the release of AOM. Furthermore, they are labor-intensive, time-consuming, and expensive, making them suitable only for small or localized areas of large water bodies. Biological methods primarily include biofilm treatment, microbial algae removal, aquatic animal control, and aquatic plant control. Biological methods are generally used in the early stages of algae outbreaks, but they are still in their early stages of development. Their long algae removal cycles, technical and management challenges, and significant capital investment make them difficult to implement on a large scale in the short term.

[0004] With the advancement of high-tech and materials science, new pollution removal technologies and materials are constantly being developed and innovated. Photocatalytic oxidation technology and photocatalytic materials, due to their environmentally friendly and energy-saving features, controllable operating conditions, mild reaction conditions, and strong ability to oxidize organic matter, have been widely researched and applied. They have also provided new approaches for oxidative algae removal. Using photocatalytic technology as a pre-oxidation method to enhance coagulation not only significantly improves algae removal effectiveness but also reduces coagulant dosage, making it a highly researchable algae removal technology.

[0005] However, practical applications of photocatalytic water treatment technology often face a challenge: the separation and recovery of photocatalyst powder. To address this issue, some existing technologies have proposed the following two approaches: 1) Composite photocatalysts with bulk materials to prepare bulk-material-loaded photocatalytic materials. Bulk materials that can serve as substrates include two categories: porous materials with high surface areas, such as carbon nanotubes, activated carbon, and zeolites; and surface-reticulated materials, such as glass, ceramics, or fibers. However, the effects of factors such as pH, temperature, and photocatalyst dosage on the kinetic properties of photocatalyst loading on porous materials are not fully understood. Furthermore, the resulting photocatalyst films exhibit weaknesses such as detachment and cracking. 2) Composite photocatalysts with magnetic materials to prepare magnetic photocatalytic materials. For example, TiO2 can be directly loaded onto magnetic materials, or a photochemically inert inorganic material can be coated onto a magnetic material, followed by TiO2 coating the inert material to prepare a magnetic photocatalyst. While these approaches can address the difficulty of photocatalyst separation to some extent, their actual water treatment efficiency and catalyst recovery rates remain low. Summary of the Invention

[0006] The purpose of the present invention is to propose a method and system for treating algae-containing water sources, which can magnetically separate sludge and a photocatalyst composited with a magnetic material (magnetic photocatalyst), and self-purify and reflux the separated magnetic photocatalyst to achieve the recycling of the magnetic photocatalyst. It can not only save the dosage of the photocatalyst; it can also promote the coagulation effect in the subsequent process, save the dosage of the coagulant, and improve the water quality after sedimentation.

[0007] The present invention first provides the following technical solutions:

[0008] A water treatment system for an algae-containing water source based on high-gradient magnetic separation comprises: a photocatalytic pool (1) connected to an algae-containing water source (W) through an inlet pipe and performing a photocatalytic reaction on the algae-containing water source (W), a mixing pool (2), a flocculation pool (3), a sedimentation pool (4), a sludge storage pool (5), a sludge regulating pool (7), the high-gradient magnetic cyclonic separation device (9) connected to the sludge regulating pool (7) through the inlet pipe (904), and a purification pool (10) connected to the high-gradient magnetic cyclonic separation device (9) through the liquid outlet pipe (903) and purifying the separated magnetic photocatalyst; the sludge regulating pool (7) and the sludge outlet pipe (902) of the high-gradient magnetic cyclonic separation device (9) are respectively connected to a sludge post-treatment unit (8) for performing sludge post-treatment; the inlet pipe is also connected to the purification pool and a dosing tank (103) for adding a magnetic photocatalyst; wherein the high-gradient magnetic cyclonic separation device (9) comprises: a cyclonic separation unit (10) for performing a sludge post-treatment; The invention relates to a device and an electromagnetic field generating device, wherein the cyclone separator comprises a cyclone cylinder (901) for performing cyclone separation, a sludge outlet pipe (902) located at the bottom of the cyclone cylinder (901) for discharging separated sludge, a liquid outlet pipe (903) located at the top of the cyclone cylinder (901) for discharging separated liquid, an inlet pipe (904) located at one side of the upper part of the cyclone cylinder (901) for the entry of materials to be separated, and a backwash pump (905) located at one side of the lower part of the cyclone cylinder (901) for connecting to the backwash pump. 106) is connected to a backwash pipe (905), the sludge outlet pipe (902), the liquid outlet pipe (903), the inlet pipe (904), and the backwash pipe (905) are all connected to the cyclone cylinder (901), and the electromagnetic field generating device (906) includes an energized solenoid containing core iron arranged in the cyclone cylinder (901), and the arrangement method enables the electromagnetic field generating device to generate a magnetic field strength of 80,000-250,000 amperes / meter.

[0009] Under this technical solution, the magnetic photocatalyst not only plays a photocatalytic role, but also, after the photocatalytic reaction, it enters the mixing tank with the fluid and is evenly dispersed. After further entering the flocculation tank, it can form a flocculation material with a magnetic material as the core with the flocculant, thereby enhancing the flocculation effect and allowing the flocculant to be recovered together with the magnetic photocatalyst, which not only reduces the amount of magnetic photocatalyst, but also reduces the amount of flocculant.

[0010] Under this technical solution, the high-gradient magnetic cyclone separator can separate muddy water containing a magnetic photocatalyst and its associated flocculant from muddy agent under power-on conditions, using the combined effects of high-speed centrifugation and an applied magnetic field. When powered, the solenoid coil generates a uniform electromagnetic field. Simultaneously, the ferromagnetic wire within the electromagnetic field is magnetized, stimulating a new magnetic field. This uniform magnetic field changes, forming a region near its surface with a non-uniform magnetic field whose gradient varies with distance, known as a high-gradient magnetic field. This high-gradient magnetic field separates the water, while the magnetic photocatalyst and its associated flocculant are trapped through centrifugation and magnetic adsorption.

[0011] According to some preferred embodiments of the present invention, the solenoid is housed in an isolation tube (916), which is made of metal and is arranged on the axis of the cyclone cylinder (901). The solenoid can be isolated from other parts of the cyclone cylinder (901) and serves as a protective device to prevent the solenoid from contacting other parts. The isolation tube (916) is fixed to the cyclone cylinder (901) through a plurality of support members (917) fixed at both ends to the outer wall of the isolation tube (916) and the inner wall of the cyclone cylinder (901). A plurality of openings (912) are provided on the isolation tube (916). The solenoid is electrically connected to a power supply (913) through a plurality of wires inserted into the openings (912). A current switch (915) is provided between each wire and the power supply (913).

[0012] This preferred embodiment effectively controls the required solenoid coil length, thereby achieving control over the magnetic field strength. When powered, the magnetic composite material adheres to the outer wall of the isolation tube under the influence of the magnetic field, protecting the solenoid while achieving excellent collection and fixation.

[0013] According to some preferred embodiments of the present invention, the length of the solenoid is 5-8 times the diameter of its core iron.

[0014] According to some preferred embodiments of the present invention, the solenoid comprises a polyimide enamel layer.

[0015] According to some preferred embodiments of the present invention, the high-gradient magnetic cyclone separation device (9) is further provided with a liquid drain valve (907) and a cooling device, wherein the liquid drain valve (907) is located on the liquid outlet pipe (903); the cooling device comprises a tubular densitometer constant temperature water bath cooler (909) surrounding the cyclone cylinder (901), a liquid reservoir (910) and a compressor (911) connected to the cooler in sequence, and two gas shut-off valves (908) respectively located between the inlet and outlet of the densitometer constant temperature water bath cooler (909) and the compressor (911) or the liquid reservoir (910).

[0016] According to some preferred embodiments of the present invention, the photocatalytic cell (1) includes multiple layers of photocatalytic reaction chambers, each layer of the photocatalytic reaction chambers contains a water inlet pipe connected to the dosing tank (103), the upper part of each layer of the photocatalytic reaction chamber is provided with an ultraviolet light source, the middle part is a reaction space, and the lower part is provided with an air aeration pipe, and the air aeration pipe is connected to a blower provided outside the photocatalytic cell (1).

[0017] According to some preferred embodiments of the present invention, the mixing tank is selected from one or more of a pipeline static mixer, a mechanical mixing tank, and a baffle mixing tank.

[0018] According to some preferred embodiments of the present invention, the flocculation tank is selected from a mechanical reaction flocculation tank or a hydraulic reaction flocculation tank.

[0019] According to some preferred embodiments of the present invention, the sedimentation tank is selected from a horizontal flow sedimentation tank or a radial flow sedimentation tank.

[0020] According to some preferred embodiments of the present invention, the photocatalytic pool (1) is connected to the algae-containing water source (W) via a lift pump (101).

[0021] According to some preferred embodiments of the present invention, the dosing tank (103) is connected to the water inlet pipe via a dosing pump (102).

[0022] According to some preferred embodiments of the present invention, the sludge regulating tank (7) is connected to the inlet pipe (904) via a sludge pump (105).

[0023] According to some preferred embodiments of the present invention, the purification tank (10) is connected to the water inlet pipe via a reflux pump (107).

[0024] According to some preferred embodiments of the present invention, the liquid outlet pipe (903) of the high-gradient magnetic cyclonic separation device (9) is connected to the purification tank (10) through a purified liquid tank and a post-flushing liquid pump that are sequentially arranged.

[0025] The present invention further provides a method for treating algae-containing water, which comprises:

[0026] Adding the algae-containing water source (W) to the photocatalytic pool (1) through the water inlet pipe, and performing a photocatalytic pre-oxidation reaction with the magnetic photocatalyst obtained from the dosing tank (103) in the photocatalytic pool (1), thereby obtaining a first water mixture containing the reacted magnetic photocatalyst;

[0027] Adding the first water mixture into the mixing tank (2) for uniform mixing to obtain a second water mixture;

[0028] adding the second water mixture into the flocculation tank (3) and performing flocculation treatment with a flocculant;

[0029] The water obtained by the flocculation treatment is used as sedimentation water, and the obtained flocculent is added to the sedimentation tank (4) for sedimentation to obtain sediment;

[0030] The precipitate is added to the sludge storage tank (5) for storage, and then added to the sludge conditioning tank (7) for concentration to obtain a sludge mixture;

[0031] 40-60% of the sludge mixture is added to the high-gradient magnetic cyclone separation device (9) for magnetic separation, and the remaining sludge mixture is fed into the sludge post-processing unit (8) for post-processing;

[0032] The third water mixture obtained by the magnetic separation and containing the reacted magnetic photocatalyst and the flocculant combined therewith is added to the purification tank (10) for activation treatment, and the separated sludge is added to the sludge post-treatment unit (8) for post-treatment;

[0033] adding the mixed slurry of the magnetic photocatalyst and flocculant obtained by the activation treatment into the water inlet pipe for recycling;

[0034] Wherein, the magnetic separation comprises:

[0035] The cyclone separator is turned on, and the solenoid is energized to separate the sludge in the sludge mixture from the reacted magnetic photocatalyst and the flocculant combined with it. The sludge is further discharged from the sludge outlet pipe (902), and the reacted magnetic photocatalyst and the flocculant combined with it are adsorbed in the cyclone cylinder (901). Thereafter, the inlet pipe (904) and the sludge outlet pipe (902) are closed, the solenoid is de-energized, and the backwash pump (106) is started to discharge the reacted magnetic photocatalyst and flocculant from the liquid outlet pipe (903) under the action of backwashing and enter the purification tank (10).

[0036] According to some preferred embodiments of the present invention, the activation treatment comprises: introducing a regeneration liquid into the purification tank (10), and regenerating the reacted magnetic photocatalyst in situ under the action of ultraviolet light, wherein the regeneration liquid is 0.02-0.1 mM H2O2 or a persulfate aqueous solution, and / or the in situ regeneration time is 30-60 min.

[0037] According to some preferred embodiments of the present invention, the magnetic photocatalyst is a composite material of Fe3O4 and TiO2.

[0038] According to some preferred embodiments of the present invention, the flocculant is selected from aluminum-based flocculants, more preferably, aluminum sulfate flocculant.

[0039] According to some preferred embodiments of the present invention, the input amount of the magnetic photocatalyst is 0.8-1.2 g / L.

[0040] According to some preferred embodiments of the present invention, the pre-oxidation treatment time is 1.5 to 2.5 hours.

[0041] According to some preferred embodiments of the present invention, the hydraulic retention time in the mixing tank is 0.5 to 1 min, and the velocity gradient is 800 to 1000 s. -1 .

[0042] According to some preferred embodiments of the present invention, the hydraulic retention time of the flocculation tank is 15 to 20 minutes, and the average velocity gradient is 20 to 50 seconds. -1 .

[0043] According to some preferred embodiments of the present invention, the speed at which the mud-water mixture enters the high-gradient magnetic cyclone separator is 0.05-0.2 m / s.

[0044] According to some preferred embodiments of the present invention, the DOC content of the algae-containing water source is 0-5 mg / L.

[0045] The present invention has the following beneficial effects:

[0046] The treatment system or treatment method of the present invention combines centrifugal action and high-gradient magnetic field adsorption separation action by utilizing a cyclone separator and an additional high-gradient magnetic field, thereby optimizing the separation and reflux of the traditional water treatment process and being able to effectively separate and recover the magnetic photocatalyst, with a recovery rate of over 85%.

[0047] The high-gradient magnetic cyclone separator used in the present invention can simultaneously recycle the flocculant combined with the magnetic photocatalyst, thereby improving the utilization rate of the flocculant.

[0048] (3) The present invention can determine the magnetic field strength of the high-gradient magnetic cyclone separator according to the characteristics of the magnetic photocatalyst and the amount of water to be treated, thereby realizing automatic control, saving labor costs, improving operation accuracy, and enhancing water supply safety.

[0049] (4) The present invention can effectively recycle the magnetic photocatalyst and flocculant, enhance the flocculation effect, reduce the treatment load of the sedimentation tank, increase the reuse rate of the magnetic photocatalyst, reduce the amount of photocatalyst re-dosing in the photocatalytic pre-oxidation process, and reduce economic costs.

[0050] (5) The treatment method of the present invention can reduce the dosage of magnetic photocatalyst by 35 to 50 percentage points and the dosage of flocculant by 30 to 40 percentage points. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 This is a connection structure diagram of the water treatment system of the present invention.

[0052] Figure 2 It is a structural schematic diagram of the high gradient magnetic cyclone separation device of the present invention.

[0053] Figure 3 This is a schematic diagram of the solenoid arrangement structure of the high gradient magnetic cyclonic separation device of the present invention.

[0054] Figure 4 This is a schematic structural diagram of the cooling device of the high-gradient magnetic cyclonic separation device of the present invention.

[0055] Figure 5 It is a schematic diagram of the combined structure of the cooling device and the high gradient magnetic separation cyclone of the present invention.

[0056] Figure 6 Schematic diagram of the structure of the photocatalytic cell of the present invention.

[0057] Among them, W-water source 101-lift pump 102-dosing pump 103-dosing tank 104-static tube mixer 105-sludge pump 106-backwash pump 107-catalyst reflux pump 1-photocatalytic tank 2-mixing tank 3-flocculation tank 4-sedimentation tank 5-sludge storage tank 6-post-settling water 7-sludge regulating tank 8-sludge subsequent treatment tank 9-high gradient magnetic cyclone separator 10-purification tank DETAILED DESCRIPTION

[0058] The present invention is described in detail below with reference to the embodiments and accompanying drawings. However, it should be understood that the embodiments and accompanying drawings are merely exemplary descriptions of the present invention and do not constitute any limitation on the scope of protection of the present invention. All reasonable variations and combinations within the scope of the inventive concept of the present invention fall within the scope of protection of the present invention.

[0059] Refer to the attached Figure 1 A specific embodiment of the water treatment system of the present invention includes:

[0060] The photocatalytic tank 1, mixing tank 2, flocculation tank 3, sedimentation tank 4, sludge storage tank 5, sludge regulating tank 7, high gradient magnetic cyclone separation device 9, and purification tank 10 are connected to the algae-containing water source W through the water inlet pipe; the sludge regulating tank 7 and the high gradient magnetic cyclone separation device 9 are also connected to the sludge post-treatment unit 8 respectively, and the water inlet pipe is also connected to the purification tank 10 and the dosing tank 103.

[0061] The water treatment process under this structure is:

[0062] The algae-containing water source W is added to the photocatalytic pool 1 through the water inlet pipe, and the photocatalytic pool 1 performs a photocatalytic pre-oxidation reaction with the magnetic photocatalyst obtained from the dosing tank 103 to obtain a first water mixture containing the reacted magnetic photocatalyst;

[0063] Adding the first water mixture into the mixing tank 2 and uniformly mixing it to obtain a second water mixture;

[0064] The second water mixture is added to the flocculation tank 3 and flocculated with a flocculant. The actual flocculant in this process also includes a flocculant with a composite structure having a magnetic material as the core formed by combining with the reacted magnetic photocatalyst;

[0065] The water obtained by flocculation treatment is used as sedimentation water 6, and the obtained flocculent is added to the sedimentation tank 4 for sedimentation to obtain sediment;

[0066] The sediment is added to the sludge storage tank 5 for storage, and then added to the sludge conditioning tank 7 for conditioning to obtain a sludge mixture;

[0067] A portion of the sludge mixture, such as 40-60% of the sludge mixture, is added to the high gradient magnetic cyclone separation device 9 for magnetic separation, and the remaining sludge mixture is added to the sludge post-treatment unit 8 for post-treatment;

[0068] The third water mixture containing the reacted magnetic photocatalyst and the flocculant combined therewith obtained by magnetic separation is added to the purification tank 10 for activation treatment, and the separated sludge is added to the sludge post-treatment unit 8 for post-treatment;

[0069] The mixed slurry of the magnetic photocatalyst and flocculant obtained through activation treatment is added into the water inlet pipeline for recycling.

[0070] Furthermore, a lifting pump 101 may be provided between the photocatalytic pool 1 and the algae-containing water source W, and the algae-containing water source W may be lifted to different heights in the photocatalytic pool 1 by the lifting pump 101 .

[0071] Furthermore, a dosing pump 102 may be provided between the dosing tank 103 and the water inlet pipe, and the magnetic photocatalyst may be pumped into the water inlet pipe through the dosing pump 102 .

[0072] Furthermore, a static tubular mixer 104 may be provided between the photocatalytic pool 1 and the mixing pool 2 to achieve a better mixing effect.

[0073] Furthermore, a sludge pump 105 may be provided between the sludge regulating tank 7 and the high gradient magnetic cyclone separation device 9 , and the sludge in the sludge regulating tank 7 is pumped into the high gradient magnetic cyclone separation device 9 through the sludge pump 105 .

[0074] Furthermore, a purification liquid tank and a post-flushing liquid pump may be sequentially arranged between the high-gradient magnetic cyclonic flow separation device 9 and the purification tank 10 to purify the separated magnetic photocatalyst and flocculant after reaction.

[0075] Furthermore, a reflux pump 107 may be provided between the purification tank 10 and the water inlet pipe, and the regenerated and purified magnetic photocatalyst and flocculant may be pumped into the water inlet pipe through the reflux pump.

[0076] Some preferred embodiments include: the mixing tank 2 is selected from one or more of a pipeline static mixer, a mechanical mixing tank, and a baffle mixing tank; the flocculation tank 3 is selected from a mechanical flocculation tank and / or a hydraulic flocculation tank; and the sedimentation tank 4 is selected from a horizontal flow sedimentation tank and / or a radial flow sedimentation tank.

[0077] Further, see the attached Figure 2 The high gradient magnetic cyclone separation device 9 includes: a cyclone separator and an electromagnetic field generating device, wherein the cyclone separator includes a cyclone cylinder 901 for cyclone separation, a sludge outlet pipe 902 located at the bottom of the cyclone cylinder 901 for discharging the separated sludge, a liquid outlet pipe 903 located at the top of the cyclone cylinder 901 for discharging the separated liquid, an inlet pipe 904 located on one side of the upper part of the cyclone cylinder 901 for the entry of the material to be separated, and a sludge outlet pipe 902 located at the bottom of the cyclone cylinder 901 for discharging the separated sludge, and a liquid outlet pipe 903 located at the top of the cyclone cylinder 901 for the entry of the material to be separated. 01, a backwash pipe 905 connected to the backwash pump 106, a sludge outlet pipe 902, a liquid outlet pipe 903, an inlet pipe 904, and a backwash pipe 905 are all connected to the cyclone cylinder 901, and preferably, a valve for controlling the switch is provided in the connection; the electromagnetic field generating device 906 includes an energized solenoid containing core iron arranged in the cyclone cylinder 901, which forms an electromagnetic field with an intensity of 80,000-250,000 amperes / meter.

[0078] Among them, the inlet pipe 904 is connected to the sludge regulating tank 7, the liquid outlet pipe 903 is connected to the purification tank 10, and the sludge outlet pipe 902 is connected to the sludge post-processing unit 8.

[0079] Preferably, the high gradient magnetic cyclone separation device 9 is provided with a liquid drain valve 907 at the liquid outlet pipe 903, through which the liquid is drained.

[0080] The magnetic separation process under this structure is:

[0081] The cyclone separator is turned on and the solenoid is energized to separate the sludge in the sludge mixture from the reacted magnetic photocatalyst and the flocculant combined with it. The sludge is further discharged from the sludge outlet pipe 902. The reacted magnetic photocatalyst and the flocculant combined with it are adsorbed in the cyclone cylinder 901. Thereafter, the inlet pipe 904 and the sludge outlet pipe 902 are closed, the solenoid is de-energized, and the backwash pump 106 is started to discharge the reacted magnetic photocatalyst and flocculant from the liquid outlet pipe 903 under the action of backwashing and enter the purification tank 10 for purification and regeneration.

[0082] Further, see the attached Figure 3 The solenoid containing the core iron 914 is accommodated in an isolation tube 916. The isolation tube 916 is arranged on the axis inside the cyclone cylinder 901, and can isolate the solenoid from other parts inside the cyclone cylinder 901. The isolation tube 916 is fixed to the cyclone cylinder 901 by a number of support members 917 fixed to the inner wall of the isolation tube 916 and the inner wall of the cyclone cylinder 901 at both ends. A plurality of openings 912 are provided on the isolation tube 916. The solenoid is electrically connected to the power supply 913 through a plurality of wires inserted into the openings 912. A current switch 915 is provided between each wire and the power supply 913. The connection between the solenoid and the power supply 913 is controlled by turning the current switch 915 on and off, thereby controlling the magnetic field strength. In this embodiment, during the magnetic separation process, the magnetic composite material is adsorbed on the outer wall of the isolation tube 916 and can be effectively separated.

[0083] Further, see the attached Figures 4 and 5 The high-gradient magnetic cyclone separation device 9 can also be equipped with a cooling device to cool the solenoid to prevent overheating. The cooling device includes a tubular densitometer constant-temperature water bath cooler 909 surrounding the cyclone cylinder 901, a liquid reservoir 910 and a compressor 911 connected to the cooler in sequence, and two gas shut-off valves 908 located between the inlet and outlet of the densitometer constant-temperature water bath cooler 909 and the compressor 906 or the liquid reservoir 907, respectively.

[0084] Further, see the attached Figure 6 The photocatalytic pool 1 includes multiple layers of photocatalytic reaction chambers, each layer of which contains a water inlet pipe connected to the dosing tank 103. The upper part of each layer of photocatalytic reaction chamber is provided with an ultraviolet light source 1104, the middle part is a reaction space 1107, and the lower part is provided with an aeration pipe 1105. The aeration pipe is connected to a blower 1106 arranged outside the photocatalytic pool 1.

[0085] Some preferred embodiments include: the length of the solenoid is 5-8 times the diameter of its core iron; and the solenoid contains a polyimide enamel layer.

[0086] The water treatment method of the present invention is further demonstrated below with reference to the embodiments.

[0087] Example 1

[0088] The algae-containing water source used was a slightly polluted water sample containing algae-derived organic matter, with a DOC of 3.0 mg / L and UV 254 0.095cm -1 The magnetic photocatalyst is Fe3O4 / TiO2, the dosage is 0.9 g / L, a 300W xenon lamp generator is set in the photocatalytic cell as the excitation light source, and the illumination range is adjusted to 450~550W / m 2 Photocatalytic pre-oxidation was performed; 0.08 mM (in terms of aluminum) of aluminum sulfate flocculant was added to the flocculation tank; the technical parameters of the high-gradient magnetic cyclone separation device were as follows: the current was supplied by a 16A DC power supply; the wire diameter was 1.65 mm, and the coil had 9 layers; the magnetic field strength was 100,000 amperes per meter; the measured magnetic induction intensity on the surface of the steel wire fibers at both ends of the solenoid was greater than 950 gauss, and the residual magnetism was approximately 50 gauss after the current was removed.

[0089] During the treatment process, the sludge mixture flows through the high-gradient magnetic cyclone separation device at a speed of 0.2 meters per second (processing water volume is about 50 liters / hour); in the activation treatment carried out in the purification tank, 0.02mM H2O2 is added and irradiated with ultraviolet light for 2 hours, and the self-cleaned magnetic photocatalyst and flocculant obtained are returned to the photocatalytic tank.

[0090] Calculation shows that under the above process, the recovery rate of the magnetic photocatalyst is 40%. In the subsequent water treatment, the re-dosage of the magnetic photocatalyst is 0.585 g / L, and the re-dosage of the flocculant is 0.056 mM. The re-dosage of the magnetic photocatalyst is saved by 35 percentage points, and the re-dosage of the flocculant is saved by 30 percentage points.

[0091] Example 2

[0092] The algae-containing water source used was a slightly polluted water sample containing algae-derived organic matter, with a DOC of 3.5 mg / L and UV 254 0.105cm -1 The magnetic photocatalyst is Fe3O4 / TiO2, the dosage is 1.0 g / L, a 300W xenon lamp generator is set in the photocatalytic cell as the excitation light source, and the illumination range is adjusted to 450~550W / m 2 Photocatalytic pre-oxidation was carried out; 0.1 mM (in terms of aluminum) of aluminum sulfate flocculant was added to the flocculation tank; the technical parameters of the high-gradient magnetic cyclonic separation device were as follows: the current was supplied by 220 V direct rectification; the wire diameter was 0.6 mm, and there were 20 coil layers; the magnetic field strength was 100,000 amperes per meter; the measured magnetic induction intensity on the surface of the steel wire fibers at both ends of the solenoid was greater than 950 gauss, and the residual magnetism was about 50 gauss after the current was removed.

[0093] During the treatment process, the sludge mixture flows through the high-gradient magnetic cyclone separation device at a speed of 0.06 meters per second (processing water volume is about 100 liters / hour); in the activation treatment carried out in the purification tank, 0.1mM H2O2 is added and irradiated with ultraviolet light for 2 hours, and the self-cleaned magnetic photocatalyst and flocculant obtained are returned to the photocatalytic tank.

[0094] Calculation shows that under the above process, the recovery rate of the magnetic photocatalyst is 45%. In the subsequent water treatment, the re-dosage of the magnetic photocatalyst is 0.60 g / L, and the re-dosage of the flocculant is 0.065 mM. The re-dosage of the magnetic photocatalyst is saved by 40 percentage points, and the re-dosage of the flocculant is saved by 35 percentage points.

[0095] Example 3

[0096] The algae-containing water source used was a slightly polluted water sample containing algae-derived organic matter, with a DOC of 3.8 mg / L and UV 254 0.125cm -1 The magnetic photocatalyst is Fe3O4 / TiO2, the dosage is 1.1 g / L, a 300W xenon lamp generator is set in the photocatalytic cell as the excitation light source, and the illumination range is adjusted to 450~550W / m 2 Photocatalytic pre-oxidation was performed; 0.12 mM (in terms of aluminum) of aluminum sulfate flocculant was added to the flocculation tank; the technical parameters of the high-gradient magnetic cyclone separation device were as follows: the current was supplied by 24 volt direct rectification; the wire diameter was 1.8 mm, and the coil had 10 layers; the magnetic field strength was 100,000 amperes per meter; the measured magnetic induction intensity on the surface of the steel wire fibers at both ends of the solenoid was greater than 950 gauss, and the residual magnetism was about 50 gauss after the current was removed.

[0097] During the treatment process, the sludge mixture flows through the high-gradient magnetic cyclone separation device at a speed of 0.06 meters per second (processing water volume is about 100 liters / hour); in the activation treatment carried out in the purification tank, 0.04mM sodium persulfate is added and irradiated with ultraviolet light for 1 hour, and the self-cleaned magnetic photocatalyst and flocculant obtained are returned to the photocatalytic tank.

[0098] According to calculation, under the above process, the recovery rate of the magnetic photocatalyst is 35%. In the subsequent water treatment, the re-dosage of the magnetic photocatalyst is 0.715 g / L, and the re-dosage of the flocculant is 0.078 mM. The re-dosage of the magnetic photocatalyst is saved by 35 percentage points, and the re-dosage of the flocculant is saved by 35 percentage points.

[0099] Example 4

[0100] The algae-containing water source used was a slightly polluted water sample containing algae-derived organic matter, with a DOC of 4.0 mg / L and UV 254 0.135cm-1 The magnetic photocatalyst is Fe3O4 / TiO2, the dosage is 1.2 g / L, a 300W xenon lamp generator is set in the photocatalytic cell as the excitation light source, and the illumination range is adjusted to 450~550W / m 2 Photocatalytic pre-oxidation was performed; 0.14 mM (in terms of aluminum) of aluminum sulfate flocculant was added to the flocculation tank; the technical parameters of the high-gradient magnetic cyclonic separation device were as follows: the current was supplied by a 16A DC power supply; the wire diameter was 1.5 mm, and the coil had 8 layers; the magnetic field strength was 100,000 amperes per meter; the measured magnetic induction intensity on the surface of the steel wire fibers at both ends of the solenoid was greater than 950 gauss, and the residual magnetism was approximately 50 gauss after the current was removed.

[0101] During the treatment process, the sludge mixture flows through the high-gradient magnetic cyclone separation device at a speed of 0.06 meters per second (processing water volume is about 100 liters / hour); in the activation treatment carried out in the purification tank, 0.1mM sodium persulfate is added and irradiated with ultraviolet light for 1 hour, and the self-cleaned magnetic photocatalyst and flocculant obtained are returned to the photocatalytic tank.

[0102] Calculation shows that under the above process, the recovery rate of the magnetic photocatalyst is 60%. In the subsequent water treatment, the re-dosage of the magnetic photocatalyst is 0.72 g / L, and the re-dosage of the flocculant is 0.084 mM. The re-dosage of the magnetic photocatalyst is saved by 40 percentage points, and the re-dosage of the flocculant is saved by 40 percentage points.

[0103] The above embodiments are merely preferred embodiments of the present invention, and the scope of protection of the present invention is not limited to the above embodiments. All technical solutions that fall within the scope of protection of the present invention are within the scope of protection of the present invention. It should be noted that improvements and modifications that can be made by a person skilled in the art without departing from the principles of the present invention are also considered to be within the scope of protection of the present invention.

Claims

1. Algae-containing water source treatment system based on high gradient magnetic separation, characterized in that: The invention comprises: a photocatalytic pool (1) connected to an algae-containing water source (W) through a water inlet pipe and performing a photocatalytic reaction on the algae-containing water source (W), a mixing pool (2), a flocculation pool (3), a sedimentation pool (4), a sludge storage pool (5), a sludge regulating pool (7), a high-gradient magnetic cyclone separation device (9) connected to the sludge regulating pool (7) through an inlet pipe (904), and a purification pool (10) connected to the high-gradient magnetic cyclone separation device (9) through a liquid outlet pipe (903) and purifying the separated magnetic photocatalyst; the sludge regulating pool (7) is also connected to the high-gradient magnetic cyclone separation device (9) through a liquid outlet pipe (903). The sludge outlet pipe (902) of the gradient magnetic cyclone separation device (9) is connected to the sludge post-treatment unit (8) for sludge post-treatment; the water inlet pipe is also connected to the purification tank and the dosing tank (103) for adding magnetic photocatalyst; the high gradient magnetic cyclone separation device (9) comprises: a cyclone separator and an electromagnetic field generating device, wherein the cyclone separator comprises a cyclone cylinder (901) for cyclone separation, a sludge outlet pipe (902) located at the bottom of the cyclone cylinder (901) for discharging the separated sludge, and a liquid sludge outlet pipe (902) located at the top of the cyclone cylinder (901) for discharging the separated liquid. The sludge outlet pipe (902), the liquid outlet pipe (903), the inlet pipe (904) for the material to be separated, which is located on the upper side of the cyclone cylinder (901), and the backwash pipe (905) is connected to the backwash pump (106). The sludge outlet pipe (902), the liquid outlet pipe (903), the inlet pipe (904), and the backwash pipe (905) are all connected to the cyclone cylinder (901). The electromagnetic field generating device (906) includes an energized solenoid containing a core iron and arranged in the cyclone cylinder (901). , and its arrangement is such that the electromagnetic field generating device generates a magnetic field strength of 80,000-250,000 amperes per meter; a regeneration liquid is passed through the purification tank (10) to regenerate the reacted magnetic photocatalyst in situ under the action of ultraviolet light; a flocculant is added to the flocculation tank, and the flocculant combines with the reacted magnetic photocatalyst to form a composite structure with a magnetic material as the core; a reflux pump (107) is provided between the purification tank (10) and the water inlet pipe, and the regenerated and purified magnetic photocatalyst and flocculant are pumped into the water inlet pipe through the reflux pump (107).

2. The processing system according to claim 1, wherein: The solenoid is housed in a metal isolation tube (916). The isolation tube (916) is arranged on the axis of the cyclone cylinder (901) and is fixed to the cyclone cylinder (901) via a plurality of support members (917) whose ends are respectively fixed to the outer wall of the isolation tube (916) and the inner wall of the cyclone cylinder (901). The isolation tube (916) is provided with a plurality of openings (912). The solenoid is electrically connected to a power supply (913) via a plurality of wires inserted into the openings (912). A current switch (915) is provided between each wire and the power supply (913).

3. The processing system according to claim 1, wherein: The high-gradient magnetic cyclone separation device (9) is further provided with a liquid drain valve (907) and a cooling device, wherein the liquid drain valve (907) is located on the liquid outlet pipe (903); the cooling device comprises a tubular densitometer constant temperature water bath cooler (909) surrounding the cyclone cylinder (901), a liquid reservoir (910) and a compressor (911) connected to the cooler in sequence, and two gas shut-off valves (908) respectively located between the inlet and outlet of the densitometer constant temperature water bath cooler (909) and the compressor (911) or the liquid reservoir (910).

4. The processing system according to claim 1, wherein: The photocatalytic cell (1) comprises multiple layers of photocatalytic reaction chambers, each layer of the photocatalytic reaction chambers comprises a water inlet pipe connected to the dosing tank (103), an ultraviolet light source is provided at the top of each layer of the photocatalytic reaction chamber, a reaction space is provided in the middle, and an air aeration pipe is provided at the bottom, the air aeration pipe is connected to a blower provided outside the photocatalytic cell (1).

5. The processing system according to claim 1, wherein: in, The mixing tank is selected from one or more of a pipeline static mixer, a mechanical mixing tank, and a baffle mixing tank; the flocculation tank is selected from a mechanical flocculation tank or a hydraulic flocculation tank; and the sedimentation tank is selected from a horizontal flow sedimentation tank or a radial flow sedimentation tank.

6. A method for treating algae-containing water source using the treatment system according to any one of claims 1 to 5, characterized in that: It includes: Adding the algae-containing water source (W) to the photocatalytic pool (1) through the water inlet pipe, and performing a photocatalytic pre-oxidation reaction with the magnetic photocatalyst obtained from the dosing tank (103) in the photocatalytic pool (1), thereby obtaining a first water mixture containing the reacted magnetic photocatalyst; Adding the first water mixture into the mixing tank (2) for uniform mixing to obtain a second water mixture; adding the second water mixture into the flocculation tank (3) and performing flocculation treatment with a flocculant; The water obtained by the flocculation treatment is used as sedimentation water, and the obtained flocculent is added to the sedimentation tank (4) for sedimentation to obtain sediment; The precipitate is added to the sludge storage tank (5) for storage, and then added to the sludge conditioning tank (7) for concentration to obtain a sludge mixture; 40-60% of the sludge mixture is added to the high-gradient magnetic cyclone separation device (9) for magnetic separation, and the remaining sludge mixture is fed into the sludge post-processing unit (8) for post-processing; The third water mixture obtained by the magnetic separation and containing the reacted magnetic photocatalyst and the flocculant combined therewith is added to the purification tank (10) for activation treatment, and the separated sludge is added to the sludge post-treatment unit (8) for post-treatment; adding the mixed slurry of the magnetic photocatalyst and flocculant obtained by the activation treatment into the water inlet pipe for recycling; Wherein, the magnetic separation comprises: The cyclone separator is turned on, and the solenoid is energized to separate the sludge in the sludge mixture from the reacted magnetic photocatalyst and the flocculant combined with it. The sludge is further discharged from the sludge outlet pipe (902), and the reacted magnetic photocatalyst and the flocculant combined with it are adsorbed in the cyclone cylinder (901). Thereafter, the inlet pipe (904) and the sludge outlet pipe (902) are closed, the solenoid is de-energized, and the backwash pump (106) is started to discharge the reacted magnetic photocatalyst and flocculant from the liquid outlet pipe (903) under the action of backwashing and enter the purification tank (10).

7. The processing method according to claim 6, characterized in that The activation treatment includes: introducing a regeneration liquid into the purification tank (10), and regenerating the reacted magnetic photocatalyst in situ under the action of ultraviolet light, wherein the regeneration liquid is 0.02-0.1mM H2O2 or a persulfate aqueous solution, and the in situ regeneration time is 30-60min.

8. The processing method according to claim 6, characterized in that The magnetic photocatalyst is a composite material of Fe3O4 and TiO2, and the flocculant is selected from aluminum flocculants.

9. The processing method according to claim 6, characterized in that: in, The input amount of the magnetic photocatalyst is 0.8-1.2 g / L; and / or, the pre-oxidation reaction time is 1.5-2.5 h; the hydraulic retention time in the mixing tank is 0.5-1 min, and the velocity gradient is 800-1000 s -1 The hydraulic retention time of the flocculation tank is 15 to 20 minutes, and the average velocity gradient is 20 to 50 seconds. -1 .

10. The processing method according to claim 6, characterized in that: The sludge mixture enters the high gradient magnetic cyclone separator at a rate of 0.05 to 0.2 m / s.

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