High-salt concentrated water zero-emission treatment system

Abstract

This invention relates to a zero-discharge treatment system for high-salinity concentrated wastewater, comprising at least a first and a second sedimentation tank. A magnet assembly is provided in at least the first sedimentation tank. The upper part of the first sedimentation tank has a baffle plate with a conical through-hole at its center and a corresponding turbulence-inducing mechanism positioned above the baffle plate. The baffle plate is located above the magnet assembly. The baffle plate has at least one annular channel within its body, and a spray nozzle communicating with the annular channel is formed on its upper surface. The turbulence-inducing mechanism includes a chassis with a rotating shaft and a groove at its upper part, and an electromagnet. Multiple rings of steel wool are provided on the lower end face of the chassis. Each ring of steel wool includes multiple steel brushes. The upper ports of the spray nozzles correspond to the spaces between two adjacent rings of steel wool. The upper port of the groove is higher than the upper port of the first sedimentation tank, and multiple strip-shaped through-holes are provided on the wedge-shaped portion at its root. The electromagnet body of the electromagnet is located within the chassis body. This application can improve problems such as easy scaling and rapid membrane fouling in the zero-discharge treatment of high-salinity concentrated wastewater.

Description

Technical Field

[0001] This invention belongs to the field of high-salinity wastewater / sewage treatment technology, specifically relating to a zero-discharge treatment system for high-salinity concentrated wastewater. Background Technology

[0002] In the Zero Liquid Discharge (ZLD) process for high-salinity concentrated wastewater, "zero discharge" means that all wastewater generated by the system is 100% recycled and reused within the plant or converted into solids, with no liquid wastewater discharged into the external environment (rivers, pipe networks, soil). However, high-salinity wastewater (especially high-salinity concentrated wastewater) generally faces the following technical challenges in zero-discharge treatment due to its high salt content, high concentration of calcium, magnesium, and silicon ions, and high osmotic pressure: 1. Membrane modules such as RO, nanofiltration, and membrane distillation are prone to fouling and clogging, resulting in rapid membrane fouling, short cleaning cycles, shortened membrane life, and high operating costs. Second, during the MVR evaporation and crystallization process, dense hard scale easily forms on the heat exchange surface, requiring frequent shutdowns for scale removal, which affects the continuous operation of the system and severely restricts the improvement of wastewater treatment efficiency. 3. In high-salt environments, colloids exhibit strong stability, poor flocculation and sedimentation effects, high pretreatment load, and high operating pressure in subsequent processes. Fourth, crystalline salts have dense crystals that are prone to caking, making salt separation difficult and easily generating hazardous waste from mixed salts, resulting in low resource utilization rates. Summary of the Invention

[0003] This invention provides a zero-discharge treatment system for high-salinity concentrated water, which can improve the problems of easy scaling and rapid membrane fouling in the zero-discharge treatment process of high-salinity concentrated water.

[0004] The technical solution of the present invention is: a zero-discharge treatment system for high-salinity concentrated water, including a pretreatment unit. Referring to existing technology, the pretreatment unit includes a mixing reaction tank, a sedimentation tank group, and a water collection chamber connected to the end of the sedimentation tank group, and the discharge end of the water collection chamber is connected to the inlet end of the next-stage treatment unit.

[0005] The mixing reaction tank has a mixing zone at the bottom and a flocculation reaction zone at the top. A concentrate inlet and a reagent inlet are located at the bottom of the mixing zone. The concentrate inlet is connected to the outlet of the previous treatment unit. The reagent inlet is connected to an external reagent delivery unit, allowing the delivery of flocculation reagents to the bottom of the mixing reaction tank. The upper part of the mixing reaction tank is connected to the lower upstream side of the sedimentation tank group via a vertically extending channel. The upper and lower parts of adjacent sedimentation tanks in the sedimentation tank group are connected via a vertically extending channel.

[0006] The following improvements are made to the solution in this application: The sedimentation tank group includes at least a first sedimentation tank and a second sedimentation tank. The first sedimentation tank is adjacent to and connected to the mixing reaction tank, and a magnet assembly is provided at least in the lower middle part of the first sedimentation tank. Specifically, the upper part of the mixing reaction tank is connected to the lower part of the first sedimentation tank through the first channel. The upper part of the first sedimentation tank is connected to the lower part of the second sedimentation tank through the second channel.

[0007] Specifically, a baffle with a conical through hole at the center is provided on the upper part of the tank / cavity of the first sedimentation tank, and a corresponding turbulence mechanism is provided above the baffle.

[0008] The partition is positioned above the magnet assembly, and there is a large vertical distance between them. The flared end of the tapered through hole faces upwards.

[0009] The partition plate has at least one annular channel within its body, and the upper surface of the plate has multiple spray holes that communicate with the annular channel, arranged alternately around the circumference. The annular channel can be connected to the agent dispensing unit via an external piping system, enabling the spraying of the required agent onto the partition plate through the spray holes, thereby facilitating secondary flocculation treatment.

[0010] The turbulence-inducing mechanism includes a chassis, a rotating shaft and a groove disposed on the upper part of the chassis, and an electromagnet. The outer diameter of both the chassis and the groove is smaller than the inner diameter of the upper part of the first sedimentation tank. This allows the outer diameter of the chassis to be smaller than the outer diameter of the groove.

[0011] A vertical distance is formed between the lower end face of the chassis and the upper end face of the partition.

[0012] Meanwhile, the lower end face of the chassis is provided with multiple radially alternating rings of steel bristles, and each ring includes multiple steel brushes arranged circumferentially, with the free ends of the steel brushes extending towards the upper end face of the partition. That is, the bristles of the steel brushes can extend vertically downwards, or they can extend downwards at an angle relative to the vertical direction. The upper end of each spray hole corresponds between two adjacent rings of steel bristles.

[0013] The rotating shaft is matched with a drive device located outside the pretreatment unit, enabling it to drive the chassis to rotate relative to the first sedimentation tank and the baffle around the vertical axis.

[0014] The upper end of the trough is positioned above the upper end of the first sedimentation tank. Preferably, the height difference between the two is controlled to be greater than 5 mm, but a difference of less than 5 mm is not excluded. An annular wedge-shaped surface is formed at the root of the trough, and multiple strip-shaped through holes are provided on the wedge-shaped surface, which are arranged alternately around the circumference.

[0015] The electromagnet body of the electromagnet section is located inside the chassis body, and the electronic control system is located outside the pretreatment unit. It can be a module of the control unit of the entire sewage / wastewater treatment system.

[0016] Optionally, the bristles of the steel brush are in a fluffy, interwoven state and form a three-dimensional network, with the bristles intertwining to form dense micropores.

[0017] Alternatively, the bristles of the steel brush may be made of martensitic stainless steel or an iron-cobalt-nickel alloy.

[0018] Optionally, the lower end face of the chassis is provided with three or more steel bristle rings, and the steel bristles in each ring are arc-shaped. In the multiple steel bristle rings, the steel bristles in each adjacent pair of rings are arranged in an alternating manner. The arc extension length of the steel bristles on the middle one or more steel bristle rings is greater than the arc extension length of the steel bristles on the inner and outer sides in the radial direction.

[0019] Optionally, an aeration disc is provided at the bottom of the mixing zone within the mixing reaction tank. The aeration disc increases the upward movement of large particles in the water and also helps improve the mixing and mass transfer effect.

[0020] Optionally, a baffle plate is provided at the junction of the mixing zone and the flocculation reaction zone in the mixing reaction tank, and an agitation mechanism is provided at the top.

[0021] The baffle plate is a conical tube with the large diameter end facing upwards, and an overflow hole is formed in the center of the baffle plate.

[0022] The lower end of the shaft of the agitator passes through the overflow hole and is fitted with an upper impeller plate. The lower end face of the impeller plate is formed into a downwardly convex spherical surface. Multiple blades are arranged in a circular pattern on the side wall of the impeller plate, and the blades extend upward at an angle, so as to promote the upward flow of water when the blades rotate.

[0023] Optionally, a recessed curved groove is formed on the upper end face of the paddle disc, near the root of the shaft.

[0024] Optionally, magnet assemblies are provided in the first sedimentation tank and the second sedimentation tank respectively.

[0025] The beneficial effects of this invention are as follows: The high-salinity concentrated wastewater zero-discharge treatment system disclosed in this application can improve / overcome the problems commonly found in high-salinity concentrated wastewater zero-discharge treatment systems, such as easy scaling and rapid membrane fouling. It helps to significantly reduce the frequency of membrane cleaning, improves the scaling condition during the evaporation and crystallization process, helps inhibit the rapid formation of dense, hard scale, and reduces the number of shutdowns for scaling (extending the cycle time), thus contributing to improved wastewater / sewage treatment efficiency. In summary, this application helps to achieve stable and efficient operation of high-salinity wastewater zero-discharge systems. Attached Figure Description

[0026] Figure 1 This is a partial cross-sectional structural diagram of the scheme involved in this application.

[0027] Figure 2 for Figure 1 A magnified schematic diagram of the structure at point I in the middle.

[0028] Figure 3 This is a partial cross-sectional schematic diagram of the turbulence mechanism.

[0029] Figure 4 This is a schematic diagram of the spoiler mechanism viewed from below.

[0030] Figure 5 This is a schematic diagram of a cross-sectional structure at a local location near the partition.

[0031] Figure 6 This is a top view of the structure of the baffle plate inside the first sedimentation tank.

[0032] Figure 7 This is a cross-sectional schematic diagram of the stirring mechanism.

[0033] Figure 8 This is a top view of the stirring mechanism.

[0034] In the diagram: 10 Pretreatment unit, 11 Channel 1, 12 Channel 2; 20 Mixing reaction tank, 21 Mixing zone, 211 Concentrate inlet, 212 Reagent inlet, 213 Aeration disc, 22 Flocculation reaction zone, 221 Baffle plate, 2211 Overflow hole, 23 Agitation mechanism, 231 Slurry disc, 2311 Curved groove, 2312 Spherical surface, 232 Paddle; 30 First sedimentation tank, 31 Baffle, 311 Conical through hole, 312 Annular channel, 313 Spray hole, 32 Annular flange; 40 Second sedimentation tank; 50 Magnet assembly; 60 Turbulence mechanism, 61 Chassis, 611 Steel brush, 62 Rotating shaft, 63 Type groove, 631 Wedge-shaped surface, 632 Strip-shaped through hole, 633 Radial flange, 64 Electromagnet part; 70 Water collection chamber. Detailed Implementation

[0035] The structures, proportions, and sizes illustrated in the accompanying drawings are merely for illustrative purposes and to aid those skilled in the art in understanding and reading the invention. They are not intended to limit the scope of the invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, provided they do not affect the effectiveness or purpose of the invention, should still fall within the scope of the technical content disclosed herein. Furthermore, terms such as "upper," "lower," "front," "rear," and "middle" used in this specification are merely for clarity and not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention's implementation.

[0036] like Figures 1 to 8 The high-salinity concentrated wastewater zero-discharge treatment system shown includes a pretreatment unit 10, with an upstream treatment unit and a downstream treatment unit respectively located upstream and downstream of the pretreatment unit 10. The pretreatment unit 10 includes a mixing reaction tank 20, a sedimentation tank group, and a water collection chamber 70 connected to the end of the sedimentation tank group. The drain end of the water collection chamber 70 is connected to the inlet end of the downstream treatment unit.

[0037] The mixing reaction tank 20 has a mixing zone 21 at the bottom and a flocculation reaction zone 22 at the top. A concentrated water inlet 211, a chemical inlet 212, and an aeration disc 213 are correspondingly located at the bottom of the mixing zone 21. The concentrated water inlet 211 is connected to the outlet of the previous treatment unit. The chemical inlet 212 is connected to an external chemical dosing unit. The aeration disc 213 is connected to an external aeration device and is positioned on the inner bottom surface of the mixing zone 21. Before entering the mixing zone 21, the concentrated water has undergone necessary pretreatment, such as pH adjustment.

[0038] The upper part of the mixing reaction tank 20 and the lower part of the upstream side of the sedimentation tank group (i.e. Figure 1 The lower part of the first sedimentation tank 30 shown is connected via a vertically extending channel 11, and the upper and lower parts of each adjacent sedimentation tank in the sedimentation tank group are connected (e.g., Figure 1 The first sedimentation tank 30 and the second sedimentation tank 40 shown are connected by a channel 2 12 extending in the vertical direction.

[0039] The above-mentioned technical solutions can be implemented with reference to existing technologies. The agent dispensing unit and the aeration device are all existing units and devices. Therefore, their specific structural forms are not further limited and can be implemented with reference to existing technologies as needed.

[0040] In the technical solution of this application, the sedimentation tank group includes at least a first sedimentation tank 30 and a second sedimentation tank 40. The first sedimentation tank 30 is located upstream and adjacent to the mixing reaction tank 20, and their upper and lower ends are connected via the first channel 11, that is, the upper port of the mixing reaction tank 20 is connected to the bottom of the first sedimentation tank 30 via the first channel 11. Simultaneously, the upper part of the first sedimentation tank 30 is connected to the lower part of the second sedimentation tank 40 via the second channel 12. A magnet assembly 50 is provided at least in the lower middle part of the first sedimentation tank 30.

[0041] Figure 1 In the illustrated scheme, the magnet assembly 50 is provided in both the first sedimentation tank 30 and the second sedimentation tank 40. Each magnet in the magnet assembly 50 can be either a permanent magnet or an electromagnet. These magnets can be rectangular parallelepipeds and arranged horizontally within the sedimentation tanks.

[0042] like Figures 1 to 8 As shown, a baffle 31 with a conical through-hole 311 at its center is provided on the upper part of the first sedimentation tank 30, and a flow-turbulence mechanism 60 is provided above the baffle 31. The flared end of the conical through-hole 311 faces upward, so that the sewage / wastewater (including chemicals, etc.) in the lower part of the first sedimentation tank 30 can flow into the baffle 31 through the conical through-hole 311 and diffuse outward radially.

[0043] The partition 31 is positioned above the magnet assembly 50, and there is a relatively large vertical distance between them.

[0044] At least one annular channel 312 is provided within the body of the partition 31, and a plurality of spray holes 313, each communicating with the annular channel 312, are formed on the upper surface of the partition. The plurality of spray holes 313 are arranged alternately around the circumference. The annular channel 312 can be connected to an external agent delivery unit via an external pipeline / pipeline system, thereby enabling the spraying / injection of necessary agents (compositions / mixtures) onto the upper surface of the partition 31 through the spray holes 313.

[0045] The turbulence-disrupting mechanism 60 includes a circular chassis 61, a rotating shaft 62 and a groove 63 disposed on the upper part of the chassis 61, and an electromagnet part 64. The rotating shaft 62 is coaxially arranged with the chassis 61, and the groove 63 can be formed as an annular groove, which is coaxial with the rotating shaft 62. The upper end of the rotating shaft 62 extends vertically upward outside the pretreatment unit 10 and is matched with the output end of the gearbox disposed on the top of the pretreatment unit 10 through a gear transmission mechanism, so that the motor disposed on the gearbox can drive the rotating shaft 62 to slowly rotate around the vertical axis. That is, the rotating shaft 62 is matched with the drive device disposed outside the pretreatment unit 10, so that it can drive the chassis 61 to rotate relative to the first sedimentation tank 30 and the baffle 31 around the vertical axis.

[0046] The outer diameter of the chassis 61 and the outer diameter of the groove 63 are both smaller than the inner diameter of the upper part of the first sedimentation tank 30. Preferably, the outer diameter of the chassis 61 is smaller than the outer diameter of the groove 63, and preferably the difference between the outer diameter of the groove 63 and the inner diameter of the upper part of the first sedimentation tank 31 is controlled to be more than 8 mm.

[0047] The upper port of the groove 63 is located above the upper port of the first sedimentation tank 30, and the height difference between the two upper ports can be more than 5mm. The specific size also needs to be considered in conjunction with the difference between the outer diameter of the groove 63 and the inner diameter of the upper part of the first sedimentation tank 31, as well as the size of the inner diameter (value) of the upper part of the first sedimentation tank 31.

[0048] A vertical distance is formed between the lower end face of the chassis 61 and the upper end face of the partition 31. Simultaneously, the lower end face of the chassis 61 is provided with multiple layers / rings of steel bristles arranged radially alternately, and each layer / ring of steel bristles includes multiple steel brushes 611 arranged circumferentially. The free ends of the steel brushes 611 extend towards the upper end face of the partition 31; specifically, the bristles of the steel brushes 611 can extend (absolutely) vertically downwards, or the bristles of the steel brushes 611 can extend downwards at an angle relative to the vertical direction. The upper port of each nozzle 313 corresponds to two adjacent layers / rings of steel bristles. Figures 1 to 6 In the scheme shown, there are three layers / three rings of steel wool rings, and the upper port of the spray hole 313 is positioned between the two steel wool rings in the inner layer / inner ring.

[0049] A ring-shaped wedge-shaped portion 631 is formed at the root of the groove 63, and a plurality of strip-shaped through holes 632 are provided on the wedge-shaped portion 631, arranged alternately around the circumference. The strip-shaped through holes 632 can be inclined holes relative to the vertical direction; see [reference needed]. Figure 2 .

[0050] The electromagnet body of the electromagnet section 64 is disposed within the body of the chassis 61.

[0051] The steel brush 611 is a steel-bristled magnetic medium. Essentially, the steel brush 611 is a steel-bristled structure with high magnetic permeability, enabling it to work in conjunction with the permanent magnet system of the electromagnet component 64 to jointly form a high-gradient magnetic separation field (structure). The core function of the high-gradient magnetic separation field is to rapidly capture magnetic composite flocs, such as magnetic flocs containing colloids, silicon, heavy metals, and some hardness generated by magnetic flocculation reactions. When these flocs flow through the high-gradient magnetic separator, they are strongly adsorbed by the high-gradient magnetic field generated by the steel brush 611 / the steel-bristled magnetic medium, thereby achieving solid-liquid separation and reducing the pollution load on the subsequent membrane concentration unit. The constructed high-gradient magnetic separation field, together with the iron oxide nanofiber magnetic seeds and flocculants, enhances the purification effect in the pretreatment stage, achieving a highly efficient pretreatment effect for high-salinity wastewater.

[0052] The physical structure requirements and material requirements for the steel brush 611 are described below.

[0053] Physical structure: The overall shape of the brush adopts a fluffy interwoven fibrous steel bristle structure, which is distributed in a three-dimensional mesh and fills the gap area between the upper end face of the partition 31 and the lower end face of the chassis 61 to avoid blockage of the flow of high-salt concentrated water / wastewater. That is, it is required to ensure smooth water flow and adapt to the solid-liquid separation requirements of high-salt wastewater pretreatment. The dimensions of the steel wool are as follows: the diameter of a single steel wool is controlled between 5 and 50 μm, and the length is controlled between 5 and 20 mm. The steel wool is intertwined to form dense micropores (porosity controlled between 60% and 80%), which ensures both the uniformity of the magnetic field gradient and the efficient capture of micro magnetic composite flocs. The magnetic field adaptation structure requires the steel wool to be arranged in a disordered, interwoven pattern to avoid uneven magnetic field gradients caused by directional arrangement. This ensures that, after matching with the magnetic field system of the electromagnet part 64, the overall magnetic field gradient is ≥ T / m, meeting the requirement for rapid capture of magnetic flocs; The surface structure of the steel wool is slightly rough with no obvious burrs, which reduces water flow resistance and enhances the adsorption and adhesion of magnetic flocs, preventing the flocs from falling off.

[0054] Materials needed: The core material is ferromagnetic alloy with high magnetic permeability and high saturation magnetization. Martensitic stainless steel (such as 430 stainless steel) or iron-cobalt-nickel alloy are preferred to ensure rapid magnetization under a magnetic field of 300 to 600 mT, generating a strong magnetic field gradient and improving magnetic separation efficiency. For corrosion resistance, the material must have excellent resistance to high salt and acid / alkali (suitable for high-salt wastewater environments with pH 7.5 to 8.5 and high TDS ≥ 50000 mg / L). The surface must be passivated to prevent corrosion and rusting from long-term contact with high-salt wastewater, thus avoiding affecting the magnetic separation effect and service life. The material's mechanical properties require it to have certain toughness and strength, to be not easily broken or detached, to withstand the impact of high-salt wastewater flow (the flow rate must be adapted to the pretreatment unit's operating conditions), and to maintain the stability of its three-dimensional network structure after long-term use. The magnetic properties are required to be: permeability ≥1000μH / m, saturation magnetization ≥1.5T, low remanence and coercivity, to ensure that there is no obvious residual magnetism after the magnetic field is removed, which facilitates subsequent cleaning of magnetic mud and equipment maintenance.

[0055] The magnetization effect is strongest when the water flow (direction) cuts the magnetic field lines, i.e., when the magnetic field is arranged horizontally and vertically (i.e., the water flow direction is ⊥ the magnetic field direction).

[0056] Preferably, three or more steel bristle rings are provided on the lower end face of the chassis 61, and the steel bristle brushes 611 in each ring are arc-shaped. In the multiple rings of steel bristle rings, the steel bristle brushes 611 in adjacent rings are arranged in a staggered manner, see [reference needed]. Figure 4 The arcuate extension length of the steel brush 611 on the middle one or more steel wool rings is greater than the arcuate extension length of the steel brush 611 on the inner and outer sides in the radial direction.

[0057] like Figures 1 to 4 As shown, three rings of steel bristles are provided on the lower end surface of the chassis 61, and the steel bristles 611 in each ring are all arc-shaped (i.e., arc-shaped strips). Furthermore, the steel bristles 611 in the three rings / three layers of steel bristles are arranged in a staggered manner. The arc-shaped extension length of the steel bristles 611 on the middle ring is greater than the arc-shaped extension length of the steel bristles 611 on the inner and outer rings in the radial direction.

[0058] The theoretical process of the above scheme is introduced below. (1) Essentially, in the extremely strong local magnetic field gradient environment generated by the (high) gradient magnetic field (HGMS), i.e., the magnetic medium (such as steel wool), weakly magnetic / magnetically seeded pollutant flocs will overcome gravity, fluid resistance, and viscosity, and be directionally adsorbed onto the magnetic medium, achieving second-level solid-liquid separation; non-magnetic pollutants (such as colloids, organic matter, heavy metals, etc.) under the premise of adding magnetic seeds (Fe3O4), form magnetic composite flocs through coagulation / adsorption, and are then captured and separated by the magnetic field (i.e., magnetic loading flocculation). The added magnetic seeds can be understood as a substance in the added reagent, which may also contain flocculants, etc.

[0059] Generally, trace amounts of ferric oxide magnetic seeds, flocculants, and coagulants are added through the annular channel 312 and the nozzle 313 into the space between the opposite end faces of the partition plate 31 and the chassis 61. Furthermore, the actual reagent components added to the mixing zone 21 through the reagent injection port 212 can be referenced from existing technologies. Therefore, it should be emphasized that the innovation of this application lies in its structure, while the process methods implemented in conjunction with this structure (including the timing, composition, and amount of reagent addition at various points, the associated control intervals, frequency, acid-base and temperature environments, and magnetic strength and frequency requirements, etc.) are not the focus of this application and will not be elaborated upon.

[0060] (2) Charged ions (such as , When heavy metals and colloids are carried by a magnetic field and water flow, they are affected by the Lorentz force F=q(v×B). This causes positive and negative ions to move in opposite circular / spiral directions, significantly increasing the collision probability and the rate of ion association / nucleation. This inhibits the formation of hard scale (calcite) and promotes the precipitation of soft scale (aragonite), thus achieving the purpose of scale prevention / removal. Because magnetic fields can alter the crystallization pathways of CaCO3 and CaSO4, transforming them from dense calcite to loose aragonite / spherulite, scale is less likely to adhere to the pipe wall and is easier to flush, thus inhibiting nucleation; Lorentz force , and Rapid association (i.e., the phenomenon of ion association) crystallizes in the main water ahead of time, rather than forming scale on the heat exchange surface; In addition, for high-salinity concentrated water, a magnetic field can reduce water viscosity, enhance ion diffusion, strengthen the mass transfer efficiency of membrane distillation (MD) and evaporation, reduce membrane fouling, and improve the concentration limit.

[0061] (3) The directional deflection and aggregation of charged colloidal particles can enhance destabilization and flocculation, which helps to reduce the amount of flocculant used.

[0062] (4) It can promote the polarization / magnetic domain effect of water molecules and ions. Water molecules are polar molecules. The magnetic field causes their hydrogen bonds to break, the association chains to shorten, and the molecular clusters to become smaller. The viscosity of water decreases, the surface tension weakens, and the dissolution / mass transfer capacity is enhanced, which is conducive to the desorption, diffusion and reaction of pollutants. Metal ions / salts have electron orbit distortion, magnetic moment orientation and polarization enhanced in the magnetic field, which changes the crystallization habit, inhibits dense hard scale and generates loose and easy-to-peel crystals. Heavy metal ions are more likely to combine with precipitants / adsorbents, and the removal rate is improved.

[0063] Magnetic flocculation / magnetic separation (solid-liquid separation) implementation requirements: Magnetic seed loading involves adding Fe3O4 magnetic powder (i.e., magnetic seed) as the core of the floc, which adsorbs pollutants and increases the density of the floc (specific gravity 3 to 5 g / cm³, which is significantly higher than the conventional 1.0 to 1.2). Specifically, magnetic seeds (Fe3O4 magnetic powder, particle size 10 to 50 μm) can be added to the mixing zone 21 and the annular channel 312 in synergy with coagulant (PAC / PFS) and coagulant aid (PAM) to form high-density magnetic flocs. These flocs settle rapidly by gravity and magnetic force, making it easy to recycle the magnetic seeds.

[0064] The magnetic field is enhanced. The external magnetic field (100 to 500 mT) formed by the electromagnet part 64 can cause the magnetic flocs to align and aggregate rapidly along the magnetic field lines, so that the settling speed can reach 20 to 50 m / h (a huge increase compared to the conventional 2 to 5 m / h), and the residence time is shortened to 5 to 15 minutes. (In a magnetic environment, the steel brush 611 promotes) high-gradient magnetic trapping, where the magnetic medium generates a strong gradient to capture tiny magnetic flocs (μm level), removing suspended solids, colloids, phosphorus, heavy metals, and bacteria with an efficiency of over 95%.

[0065] Throughout the entire process, the actual "sedimentation" action only occurs in the sedimentation tank. That is, in the mixing zone 21, only the reagent (which may contain a small amount of magnetic seed) is added to promote mixing, and no sedimentation occurs; in the flocculation reaction zone 22, magnetic flocs begin to form and may be affected by the magnetic field, but do not settle; in the sedimentation tank, under the influence of the magnet assembly 50 and the electromagnet part 64, the magnetic flocs settle under the enhanced magnetic force.

[0066] Example 1 of the mixing reaction tank 20: magnetic loading coagulation, that is, no magnetic field is added to the flocculation reaction zone 22, only magnetic seeds, flocculants, coagulants, etc. are added.

[0067] Principle: The magnetic seed is simply "added" to act as the floc skeleton, making the flocs heavier and denser; flocculation relies on coagulant + stirring, not magnetic force.

[0068] The purpose of placing a magnetic field only in the sedimentation tank is to accelerate and compact the already formed magnetic flocs during sedimentation.

[0069] Example 2 of the mixing reaction tank 20: "Magnetic flocculation / magnetized flocculation", that is, in The flocculation reaction zone 22 is also equipped with a weak magnetic field to accelerate the collision and arrangement of flocs, so that the flocs grow faster and denser; however, the magnetic field here does not have to be present all the time, it is enough to be present in the middle and late stages of flocculation, and it is also possible to keep it on throughout the process.

[0070] In short, the core of the flocculation reaction is the reagent and stirring, not the magnetic field. Flocculation can still be completed without a magnetic field.

[0071] In the technical solution of this application, when the water flows upward in the first sedimentation tank 30, it is blocked by the baffle 31, causing it to converge towards the center and surge upward. Simultaneously, under the rotating and agitating action of the chassis 61, the wastewater / fluid flows radially outward and also undergoes circumferential convection, thereby improving the mass transfer and mixing effect between the fine flocs, micro-flocs, colloids, etc., that have not yet settled in the lower chamber of the first sedimentation tank 30 and the fluid. During this process, in a (high) gradient magnetic field environment, the magnetic seeds, flocculants, and additives in the reagents added (through the nozzle 313) are also stimulated. Coagulants and other agents create a good mass transfer mixing effect with fine flocs, micro-flocs, colloids, etc. in water / fluids, promoting the rapid growth and enlargement of fine, micro-flocs, and colloids. This allows the magnetic seeds, flocculants, and coagulant aids uniformly mixed in the water / fluid / sewage to fully react after entering the molding tank 63, growing larger magnetic flocs (the electromagnet part 64 can influence the magnetic field environment of the molding tank 63, causing the flocs to be affected by the magnetic field and slowing their upward flow). Ultimately, the magnetic flocs in the sewage overflowing from the molding tank 63 into the second sedimentation tank 40 can settle in a short time. Specifically, the upper port of the molding tank 63 is positioned above the upper port of the first sedimentation tank 30 to provide a buffer space for the growth of (magnetic) flocs in the sewage, preventing them from quickly escaping the magnetic field influence of the electromagnet part 64, and allowing them sufficient growth time in the magnetic field environment without escaping in a short time.

[0072] In summary, the fine flocs, micro-flocs, and colloids that escape upward from the first sedimentation tank 30 undergo secondary flocculation in the trough 63. Through a series of charge neutralization, destabilization, adsorption bridging, and netting and sweeping actions, they can aggregate into larger and denser dense flocs, significantly improving the settling performance of the flocs. This allows for efficient settling in subsequent sedimentation units (such as the second sedimentation tank 40), achieving thorough solid-liquid separation and ensuring the stable operation of subsequent membrane concentration or evaporation crystallization systems.

[0073] To promote the mixing and mass transfer of various substances (including magnetic seeds, reagents, etc.) in the water. For example... Figure 1 , Figures 7 to 8 As shown, in the mixing reaction tank 20, a flow baffle 221 is provided at the position where the mixing zone 21 and the flocculation reaction zone 22 are connected, and an agitation mechanism 23 is provided at the top of the mixing reaction tank 20.

[0074] The baffle plate 221 is a conical cylinder with its larger diameter end facing upwards, and an overflow hole 2211 is formed at the center of the baffle plate 221. The lower end of the shaft of the agitation mechanism 23 passes through the overflow hole 2211 and is fitted with a paddle plate 231, so that a large vertical distance is formed between the opposite end faces of the paddle plate 231 and the baffle plate 221. The inner diameter of the overflow hole 2211 is more than twice the outer diameter of the shaft of the agitation mechanism 23, and less than half the outer diameter of the paddle plate 231.

[0075] The lower end face of the paddle tray 231 is formed as a downwardly convex spherical surface 2312. Multiple paddle blades 232 are arranged circumferentially on the side wall of the paddle tray 231. These blades 232 extend upwards at an angle (i.e., axially away from the spherical surface 2312), and are required to promote upward flow of water during rotation. During this upward flow, the agitation mechanism 23 impacts the lower conical surface of the baffle plate 221, causing turbulence (strong vertical churning and radial convection), promoting mixing of various substances in the water, and ultimately surging upwards through the overflow hole 2211 above the baffle plate 221. If a magnet is provided in the flocculation reaction zone 22, it can be placed on the baffle plate 221.

[0076] The flow baffle 221 can be positioned relatively close to the flocculation reaction zone 22, and the paddle disc 231 and paddle blade 232 can be extended to the upper middle part of the mixing zone 21.

[0077] To further promote the convection effect of water between the baffle plate 221 and the paddle plate 231, a (downward) concave curved groove 2311 can be formed on the upper end surface of the paddle plate 231, near the root of the shaft. In this way, after the water impacts the lower end conical surface of the baffle plate 221, it can impact the curved groove 2311 during the downward flow, thereby increasing the ability of the water to flow outward in the radial direction and improving the radial convection intensity of the water.

[0078] An annular flange 32 is formed on the inner wall of the first sedimentation tank 30, corresponding to the upper part of the partition 31; correspondingly, a radial flange 633 is formed on the lower part of the outer wall of the groove 63. After assembly, the radial flange 633 and the annular flange 32 are in contact and matched. To reduce the frictional resistance between the contact surfaces, ceramic balls can be embedded in the upper end face of the annular flange 32 to form a line-surface contact matching relationship between the opposite surfaces of the radial flange 633 and the annular flange 32.

[0079] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Many aspects of the present invention can be improved without departing from the overall concept. Those skilled in the art can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A zero-discharge treatment system for high-salinity concentrated wastewater, comprising a pretreatment unit (10) containing a mixing reaction tank (20) and a sedimentation tank group; the mixing reaction tank (20) has a mixing zone (21) at the bottom and a flocculation reaction zone (22) at the top; characterized in that: The sedimentation tank group includes at least a first sedimentation tank (30) and a second sedimentation tank (40); the upper part of the mixing reaction tank (20) is connected to the lower part of the first sedimentation tank (30); the upper part of the first sedimentation tank (30) is connected to the lower part of the second sedimentation tank (40); at least a magnet group (50) is provided in the first sedimentation tank (30). The upper part of the first sedimentation tank (30) is provided with a baffle (31) with a conical through hole (311) formed in the center and a turbulence mechanism (60) correspondingly provided above the baffle (31). The partition (31) is located above the magnet assembly (50), and its body is provided with at least one annular channel (312) that can be connected to the drug delivery unit. The upper plate surface is formed with multiple spray holes (313) that are respectively connected to the annular channel (312); the flared end of the conical through hole (311) faces upward. The turbulence-disrupting mechanism (60) includes a chassis (61) with a rotating shaft (62) and a groove (63) on the upper part, and an electromagnet part (64); the outer diameter of the chassis (61) and the outer diameter of the groove (63) are both smaller than the inner diameter of the upper part of the first sedimentation tank (30); a multi-ring steel wool ring is provided on the lower end face of the chassis (61); each ring of steel wool ring includes a plurality of steel brushes (611) arranged alternately around the circumference; the free end of the steel brush (611) extends toward the upper end face of the partition (31). The upper ports of the nozzles (313) are all located between two adjacent steel wool rings; the rotating shaft (62) can drive the chassis (61) to rotate around the vertical axis; the upper port of the groove (63) is located above the upper port of the first sedimentation tank (30); a wedge-shaped surface (631) is formed at the root of the groove (63); multiple strip-shaped through holes (632) are provided on the wedge-shaped surface (631) and are distributed around the circumference; the electromagnet body of the electromagnet part (64) is located in the body of the chassis (61).

2. The high-salinity concentrated wastewater zero-discharge treatment system according to claim 1, characterized in that: The bristles of the steel brush (611) are in a fluffy, interwoven state and can form a three-dimensional network. The bristles can cross and intertwine to form dense micropores.

3. The high-salinity concentrated wastewater zero-discharge treatment system according to claim 1 or 2, characterized in that: The bristles of the steel brush (611) are made of martensitic stainless steel or iron-cobalt-nickel alloy.

4. The high-salinity concentrated wastewater zero-discharge treatment system according to claim 1, characterized in that: The lower end face of the chassis (61) is provided with three or more steel bristle rings, and the steel bristle brush (611) in each ring is in the shape of an arc bristle. In the multi-ring steel wool, the steel wool brushes (611) in each adjacent two rings are arranged in an alternating manner; the arc extension length of the steel wool brush (611) on the middle ring or multiple rings is greater than the arc extension length of the steel wool brush (611) on the two side rings.

5. The high-salinity concentrated wastewater zero-discharge treatment system according to claim 1, characterized in that: An aeration disc (213) is provided at the bottom of the mixing zone (21) within the mixing reaction tank (20).

6. The high-salinity concentrated wastewater zero-discharge treatment system according to claim 1, characterized in that: Inside the mixing reaction tank (20), a baffle plate (221) is provided at the junction of the mixing zone (21) and the flocculation reaction zone (22), and an agitation mechanism (23) is provided at the top. The baffle plate (221) is a conical cylinder with the large diameter end facing upward, and an overflow hole (2211) is formed at the center of the baffle plate (221). The shaft of the agitation mechanism (23) passes through the overflow hole (2211) and is then fitted with an upper slurry plate (231). The lower end face of the slurry plate (231) is formed as a downwardly convex spherical surface (2312). Multiple blades (232) are provided on the side wall of the slurry plate (231) and are arranged in a circumferentially alternating pattern. The blades (232) extend upward at an angle, and when the blades (232) rotate, they can promote the upward flow of water.

7. The high-salinity concentrated wastewater zero-discharge treatment system according to claim 6, characterized in that: A recessed curved groove (2311) is formed on the upper end face of the paddle disc (231) and near the root of the shaft.

8. The high-salinity concentrated wastewater zero-discharge treatment system according to claim 1, characterized in that: Magnet groups (50) are respectively installed in the first sedimentation tank (30) and the second sedimentation tank (40).

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