A method for treating reverse osmosis concentrated water

Abstract

The present invention relates to the technical field of sewage treatment, and in particular to a method for treating reverse osmosis concentrated water. The treatment method comprises: passing the reverse osmosis concentrated water into a crystallization system for crystallization, and dynamically adding a scale inhibitor and a coagulant in the crystallization system to obtain purified water. The treatment method provided by the present invention is for reverse osmosis concentrated water with calcium sulfate hardness as the main component, and dynamically and accurately controls the dosage of the scale inhibitor and the coagulant according to the water inlet, calcium sulfate hardness and effluent turbidity, thereby ensuring the effluent hardness and turbidity, avoiding the subsequent scaling risk, thereby eliminating the need for subsequent flocculation sedimentation tanks and other equipment, and effectively reducing costs.

Description

Technical Field

[0001] The invention relates to the technical field of sewage treatment, and in particular to a method for treating reverse osmosis concentrated water. Background Art

[0002] For the removal of hardness in reverse osmosis concentrate with calcium sulfate hardness as the main component, multi-stage reverse osmosis concentration can be used to make full use of the characteristic that the concentration product of calcium sulfate in reverse osmosis concentrate is higher than its solubility product. The crystallization process is used to directly precipitate calcium sulfate crystals, and the water quality with permanent hardness as the main component is transformed into water quality with temporary hardness as the main component, thus achieving the complete removal of permanent hardness and avoiding the use of sodium carbonate. This method has many advantages: (1) Low operating cost. Under the same hardness removal, the operating cost is only 10-15% of that of sodium carbonate; (2) The product is a crystalline solid, which is easy to dehydrate and has a low sludge moisture content, usually 5-10%; (3) The purity of the generated calcium sulfate is as high as 98% or more, and can be used as a building material or raw material for cement production.

[0003] However, the calcium sulfate crystallization process requires the addition of scale inhibitors and removers. The amount of scale inhibitors and removers added has a great influence on the hardness and turbidity of the effluent, resulting in unstable effluent. Fine crystals (particle size <50 μm) often flow out of the system with the effluent, causing the turbidity and hardness of the subsequent treatment system to exceed the standard. The crystallization continues slowly, and broken crystals and flocculants complexes will appear inside the crystallizer, which are difficult to settle, resulting in a high effluent SS (suspended solids concentration). Subsequently, a flocculation sedimentation tank needs to be added to ensure that the effluent turbidity meets the process requirements, resulting in a long process flow. At the same time, this method transfers the operation problem to the back process end and fails to fundamentally solve the problem. The flocculation sedimentation tank itself also faces a large risk of scaling and is difficult to operate for a long time. The sludge formed has a high water content, a large amount of sludge cannot be recovered, and the treatment is difficult. In addition, coagulants are usually added to the crystallizer to control the turbidity of the effluent, but the crystallizer process is different from conventional flocculation sedimentation. The presence of excessive coagulants will affect the crystal morphology, resulting in seed failure, low crystallization efficiency, and high effluent hardness.

[0004] Therefore, it is hoped to provide a method for treating reverse osmosis concentrate with calcium sulfate hardness as the main factor to achieve simultaneous control of scale inhibitors, removers and coagulants, thereby ensuring that the effluent hardness and turbidity meet the standards. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a method for treating reverse osmosis concentrate. The treatment method provided by the present invention is for reverse osmosis concentrate with calcium sulfate hardness as the main component. The dosage of scale inhibitor remover and coagulant aid is dynamically and accurately controlled according to the water inlet volume, calcium sulfate hardness and effluent turbidity, thereby ensuring the effluent hardness and turbidity and avoiding the subsequent scaling risk, thereby eliminating the need for subsequent flocculation sedimentation tanks and other equipment, effectively reducing costs.

[0006] In a first aspect, the present invention provides a method for treating reverse osmosis concentrated water, the method comprising:

[0007] The reverse osmosis concentrated water is passed into the crystallization system for crystallization, and the scale inhibitor, remover and coagulant are dynamically added into the crystallization system to obtain purified water;

[0008] The dosage of the antiscalant remover is Q1,

[0009] Q1=C1÷1000÷ρ1×Q in ;

[0010] Wherein, Q1-dosage of scale inhibitor and remover, L / h;

[0011] C1- scale inhibitor removal agent dosage concentration, mg / L;

[0012] ρ1- scale inhibitor remover agent density, g / cm 3 ;

[0013] Q in -water intake, m³ / h;

[0014] The dosage of the coagulant aid is Q2,

[0015] Q2=Q in ×C2÷ρ2

[0016] in:

[0017] Q2-dosage of coagulant aid, L / h;

[0018] Q in -water intake, m³ / h;

[0019] C2-coagulant concentration, mg / L;

[0020] ρ2-coagulant preparation concentration, g / L.

[0021] The treatment method provided by the present invention is aimed at reverse osmosis concentrated water with calcium sulfate hardness as the main component, and the dosage of the scale inhibitor remover and the coagulant aid is dynamically and accurately controlled according to the water inlet, calcium sulfate hardness and effluent turbidity, thereby ensuring the effluent hardness and turbidity, avoiding the subsequent scaling risk, thereby eliminating the need for subsequent flocculation sedimentation tanks and other equipment, and effectively reducing costs. Specifically:

[0022] The treatment method provided by the present invention passes reverse osmosis concentrate into a crystallization system for crystallization. On the one hand, the present invention finds the relationship between the dosage of a scale inhibitor remover and the water inflow and hardness of the reverse osmosis concentrate, and dynamically controls the dosage of the scale inhibitor remover according to the water inflow and hardness of the reverse osmosis concentrate to destroy the scale inhibitor, thereby removing supersaturated calcium sulfate through crystallization. On the other hand, the present invention finds the relationship between the dosage of a coagulant aid and the water inflow and turbidity value of the reverse osmosis concentrate, and dynamically controls the dosage of the coagulant aid according to the water inflow and turbidity of the reverse osmosis concentrate to avoid the negative impact of excessive dosage on the crystallization of calcium sulfate, while leaving fine crystals in the crystallization system, thereby ensuring the hardness and turbidity of the effluent water, avoiding the subsequent scaling risk, and reducing the investment in subsequent process units.

[0023] As a preferred technical solution of the present invention, C1=Δcond / k, wherein Δcond is the difference between the inlet water conductivity and the target conductivity, and k is the dosing coefficient, which is between 20 and 30, for example, 20, 22, 24, 26, 28, 30, etc.

[0024] The present invention finds the relationship between the dosing concentration C1 of the scale inhibitor remover and the influent conductivity and the target conductivity. When it is within the above range, the dosage of the scale inhibitor remover can be accurately controlled within a suitable range, effectively destroying the scale inhibitor in the reverse osmosis concentrated water, thereby generating CaSO4·2H2O crystals and achieving hardness removal.

[0025] As a preferred technical solution of the present invention, the C2=NTU out ÷10, where NTU out is the effluent turbidity value.

[0026] The present invention finds the relationship between the concentration of coagulant and the turbidity value of the effluent water. When the above relationship is met, the dosage of the coagulant can be accurately controlled within a suitable range, thus avoiding the problems of seed failure, low crystallization efficiency, high effluent hardness, etc. caused by excessive dosage.

[0027] As a preferred technical solution of the present invention, 0.2≤C2≤2.5, for example, C2 can be 0.2, 0.5, 1.0, 1.5, 2.0, 2.5, etc.

[0028] As a preferred technical solution of the present invention, the reverse osmosis concentrated water includes calcium ions and sulfate ions.

[0029] The treatment method provided by the present invention is mainly aimed at removing the hardness in reverse osmosis concentrated water mainly composed of calcium sulfate hardness. The permanent hardness is completely removed by dynamically controlling the dosage of scale inhibitor remover and coagulant to crystallize calcium sulfate.

[0030] As a preferred technical solution of the present invention, the scale inhibitor remover includes any one or more of polyaluminium chloride, polyferric sulfate and ferric chloride.

[0031] As a preferred technical solution of the present invention, the coagulant aid includes polyacrylamide.

[0032] As a preferred technical solution of the present invention, the treatment method utilizes a reverse osmosis concentrated water crystallization system for crystallization, and the reverse osmosis concentrated water crystallization system includes a water inlet pipeline, a crystallization device and a dosing system;

[0033] The crystallization device comprises an outer cylinder, a guide cylinder, a water inlet, a water outlet and an agitator. The guide cylinder is arranged inside the outer cylinder and is a structure with upper and lower ends opening; the water inlet is arranged on the outer cylinder and leads to the lower end inside the guide cylinder; the water outlet is arranged at the upper end of the outer cylinder; the agitator is arranged at the lower end of the outer cylinder and extends into the guide cylinder, and is used to make the reverse osmosis concentrated water flow from bottom to top in the guide cylinder and overflow to the outer cylinder to form a cycle;

[0034] The water inlet pipe is connected to the water inlet of the crystallization device and is used to pass reverse osmosis concentrated water into the crystallization device;

[0035] The dosing system includes a first dosing device and a second dosing device. The first dosing device is used to add scale inhibitor and remover, and the dosing point is located in the guide tube of the crystallization device; the second dosing device is used to add coagulant aid, and the dosing point is located between the guide tube and the outer tube of the crystallization device.

[0036] The reverse osmosis concentrate treatment method provided by the present invention is implemented by utilizing the reverse osmosis concentrate crystallization system. When the high-salt reverse osmosis concentrate enters the crystallization system, the crystallization device forms certain hydraulic conditions through stirring, so that the crystals are in a suspended state with gradient uniform distribution, creating good conditions for the growth of CaSO4·2H2O crystals. At the same time, the scale inhibitor is destroyed by dynamically controlling the dosage of the scale inhibitor remover, so that the supersaturated calcium sulfate is crystallized and removed, and the fine crystals are retained in the crystallization system by controlling the dosage of the coagulant aid, so as to maintain the turbidity of the effluent water.

[0037] As a preferred technical solution of the present invention, a water inlet flow meter and a water inlet conductivity meter are arranged in the water inlet pipeline;

[0038] A water outlet turbidity meter is provided at the water outlet of the crystallization device;

[0039] A first dosing flow meter is provided in the pipeline from the first dosing device to the crystallization device;

[0040] A second dosing flow meter is provided in the pipeline from the second dosing device to the crystallization device;

[0041] The reverse osmosis concentrated water crystallization system also includes a PLC control module, which is used to monitor the detection results of the water inlet flow meter, the water inlet conductivity meter, the water outlet turbidity meter, the first dosing flow meter and the second dosing flow meter, and dynamically control the first dosing device and the second dosing device to add reagents to the crystallization device and adjust the dosing flow rate based on the detection results.

[0042] The method for treating reverse osmosis concentrated water provided by the present invention utilizes the above-mentioned reverse osmosis concentrated water crystallization system for treatment, and can realize real-time monitoring of water intake, calcium sulfate hardness and effluent turbidity, so as to dynamically control the dosage of scale inhibitor remover and coagulant aid, realize the crystallization and removal of calcium sulfate, and thus ensure that the effluent hardness and turbidity meet the standards.

[0043] As a preferred technical solution of the present invention, the processing method comprises the following steps:

[0044] The reverse osmosis concentrate is introduced into the guide tube through the water inlet pipe. Under the action of stirring, the reverse osmosis concentrate flows from bottom to top in the guide tube and overflows to the outer tube to form a cycle. The PLC control module dynamically controls the first dosing device to add scale inhibitor and remover according to the detection results of the inlet flow meter and the inlet conductivity meter, and dynamically controls the second dosing device to add coagulant according to the detection results of the inlet flow meter and the outlet turbidity meter. When the outlet water hardness and turbidity meet the standards, purified water is obtained.

[0045] The technical solution provided by the embodiment of the present invention has the following advantages compared with the prior art:

[0046] The treatment method provided by the present invention is aimed at reverse osmosis concentrated water with calcium sulfate hardness as the main component. The dosage of the scale inhibitor remover and the coagulant aid is dynamically and accurately controlled according to the water inlet volume, calcium sulfate hardness and effluent turbidity, thereby ensuring the effluent hardness and turbidity and avoiding the subsequent scaling risk, thereby eliminating the need for subsequent flocculation sedimentation tanks and other equipment, effectively reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0048] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0049] Figure 1 This is a diagram of the reverse osmosis concentrated water crystallization system used in Example 1 of the present invention;

[0050] Among them, 1-water inlet pipeline, 2-crystallization device, 3-dosing system, 4-PLC control module;

[0051] 11-water inlet flowmeter, 12-water inlet conductivity meter, 21-outer cylinder, 22-flow guide cylinder, 23-water inlet, 24-water outlet, 25-agitator, 26-outlet turbidity meter, 31-first dosing device, 32-second dosing device, 33-first dosing flowmeter, 34-second dosing flowmeter.

[0052] Figure 2 The results of water hardness and turbidity of Example 1 of the present invention are shown.

[0053] Figure 3 The results of water hardness and turbidity of Comparative Example 1 of the present invention are shown.

[0054] Figure 4 This is a SEM image of the crystal precipitate obtained in Example 1 of the present invention.

[0055] Figure 5 This is a SEM image of the crystal precipitate obtained in Comparative Example 1 of the present invention. DETAILED DESCRIPTION

[0056] In order to more clearly understand the above-mentioned objectives, features and advantages of the present invention, the scheme of the present invention will be further described below. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0057] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present invention, rather than all of the embodiments.

[0058] Example 1

[0059] This embodiment provides a method for treating reverse osmosis concentrated water, which uses a reverse osmosis concentrated water crystallization system for treatment.

[0060] The reverse osmosis concentrated water is obtained by concentrating the wastewater from a chemical fiber industry through reverse osmosis, with a sulfate concentration of 16,000 mg / L and a calcium hardness of 4,500 mg / L.

[0061] The reverse osmosis concentrated water crystallization system is as follows Figure 1 As shown, it specifically includes a water inlet pipeline 1, a crystallization device 2, a dosing system 3 and a PLC control module 4;

[0062] The crystallization device 2 includes an outer cylinder 21, a guide cylinder 22, a water inlet 23, a water outlet 24, an agitator 25 and a water outlet turbidity meter 26. The guide cylinder 22 is arranged inside the outer cylinder 21 and is a structure with upper and lower ends open; the water inlet 23 is arranged on the outer cylinder 21 and leads to the lower end of the guide cylinder 22; the water outlet 24 is arranged at the upper end of the outer cylinder 21; the water outlet turbidity meter 26 is arranged at the water outlet 24; the agitator 25 is arranged at the lower end of the outer cylinder 21 and extends into the guide cylinder 22;

[0063] The water inlet pipe 1 is connected to the water inlet 23 of the crystallization device 2, and is used to pass reverse osmosis concentrated water into the crystallization device 2. The water inlet pipe 1 is provided with a water inlet flow meter 11 and a water inlet conductivity meter 12;

[0064] The dosing system 3 includes a first dosing device 31 and a second dosing device 32. The first dosing device 31 is used to add a scale inhibitor and remover, and the dosing point is located in the guide tube 22 of the crystallization device 2. A first dosing flowmeter 33 is provided in the pipeline from the first dosing device 31 to the crystallization device 2. The second dosing device 32 is used to add a coagulant aid, and the dosing point is located between the guide tube 22 and the outer tube 21 of the crystallization device 2. A second dosing flowmeter 34 is provided in the pipeline from the second dosing device 32 to the crystallization device 2.

[0065] The PLC control module 4 is used to monitor the detection results of the water inlet flowmeter 11, the water inlet conductivity meter 12, the water outlet turbidity meter 26, the first dosing flowmeter 33 and the second dosing flowmeter 34, and dynamically control the first dosing device 31 and the second dosing device 32 to add reagents to the crystallization device 2 and adjust the dosing flow rate based on the detection results.

[0066] The processing method comprises the following steps:

[0067] The reverse osmosis concentrated water is introduced into the guide tube 22 through the water inlet pipe 1. Under the stirring action, the reverse osmosis concentrated water flows from bottom to top in the guide tube 22 and overflows to the outer tube 21 to form a cycle. The PLC control module 4 dynamically controls the first dosing device 31 to add the scale inhibitor and remover PAC according to the detection results of the water inlet flow meter 11 and the water inlet conductivity meter 12, and dynamically controls the second dosing device 32 to add the coagulant aid polyacrylamide according to the detection results of the water inlet flow meter 11 and the water outlet turbidity meter 26. When the water outlet hardness and turbidity meet the standards, purified water is obtained;

[0068] The dosage of the antiscalant remover is Q1,

[0069] Q1=C1÷1000÷ρ1×Q in ;

[0070] Wherein, C1-antiscalant removal agent dosage concentration, mg / L; C1=Δcond / k, where Δcond is the difference between the inlet conductivity and the target conductivity, k is 25, and the target conductivity is 35000μs / cm;

[0071] ρ1- scale inhibitor remover agent density, 1.4 g / cm 3 ;

[0072] Q in - water inlet, 200 m³ / h;

[0073] The dosage of the coagulant aid is Q2,

[0074] Q2=Q in ×C2÷ρ2

[0075] in:

[0076] Q in - water inlet, 200 m³ / h;

[0077] C2-coagulant concentration, mg / L; C2=NTU out ÷10, where NTU out is the effluent turbidity value;

[0078] ρ2-coagulant preparation concentration, 1 g / L.

[0079] Comparative Example 1

[0080] This comparative example provides a method for treating reverse osmosis concentrated water, wherein the reverse osmosis concentrated water is obtained by concentrating wastewater from a chemical fiber industry through reverse osmosis, wherein the sulfate concentration is 16000 mg / L and the calcium hardness is 4500 mg / L.

[0081] The treatment method is: adding 160 mg / L of scale inhibitor and remover PAC and 1.5 mg / L of coagulant aid polyacrylamide to the reverse osmosis concentrated water.

[0082] Performance Testing

[0083] 1. The water hardness and turbidity of Example 1 and Comparative Example 1 were tested. The results are as follows: Figure 2 and 3 As shown. Among them, Figure 2 The water hardness and turbidity results of Example 1 are: Figure 3 The results of water hardness and turbidity of Comparative Example 1 are shown below.

[0084] Depend on Figure 2 and Figure 3It can be found that using the reverse osmosis concentrated water treatment method provided by the present invention, the effluent hardness and turbidity are relatively stable, the effluent hardness is about 1800 mg / L, and the turbidity is between 2-12NTU. Compared with the comparative example 1, the effluent hardness is about 1950 mg / L and the turbidity is between 15-90NTU. The effluent hardness and turbidity values ​​obtained by the treatment method of the present invention are smaller, which meets the requirements of the subsequent process section.

[0085] 2. The crystal precipitates obtained in Example 1 and Comparative Example 1 were subjected to SEM test. The test results are as follows: Figure 4 and Figure 5 As shown. Among them, Figure 4 This is the SEM image of the crystal precipitate obtained in Example 1. Figure 5 This is the SEM image of the crystal precipitate obtained in Comparative Example 1.

[0086] Depend on Figure 4 and Figure 5 By comparison, it can be found that the crystal particle size obtained by the treatment method provided by the present invention is larger, indicating that the present invention can reduce the interference of PAM on the crystal morphology particle size by dynamically controlling the amount of PAM, the crystal particle size is increased, and there are more growth points on the crystal surface, which is beneficial to subsequent centrifugal dehydration.

[0087] 3. The particle size distribution of the crystals obtained in Example 1 and Comparative Example 1 was tested, and the results are shown in Table 1 and Table 2:

[0088] Table 1 Crystalline particle size distribution of Example 1

[0089]

[0090] Table 2 Comparative Example 1 Crystalline Particle Size Distribution

[0091]

[0092] It can be found from Table 1 and Table 2 that the crystal particle size obtained by the treatment method provided by the present invention is larger, indicating that the present invention can reduce the interference of PAM on the crystal morphology particle size by dynamically controlling the amount of PAM, so that the crystal particle size is increased and there are more growth points on the crystal surface, which is beneficial to subsequent centrifugal dehydration.

[0093] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0094] The above description is only a specific embodiment of the present invention, so that those skilled in the art can understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments described herein, but should conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for treating reverse osmosis concentrated water, characterized in that: The processing method comprises: The reverse osmosis concentrated water is passed into the crystallization system for crystallization, and the scale inhibitor, remover and coagulant are dynamically added into the crystallization system to obtain purified water; The dosage of the antiscalant remover is Q1, Q1=C1÷1000÷ρ1×Q in ; Wherein, Q1-dosage of scale inhibitor and remover, L / h; C1- scale inhibitor removal agent dosage concentration, mg / L; ρ1- scale inhibitor remover agent density, g / cm 3 ; Q in -water intake, m³ / h; The dosage of the coagulant aid is Q2, Q2=Q in ×C2÷ρ2 in: Q2-dosage of coagulant aid, L / h; Q in -water intake, m³ / h; C2-coagulant concentration, mg / L; ρ2-coagulant preparation concentration, g / L; C1 = Δcond / k, where Δcond is the difference between the inlet conductivity and the target conductivity, and k is the dosing coefficient, which is between 20 and 30; C2 = NTU out ÷10, where NTU out is the effluent turbidity value.

2. The processing method according to claim 1, characterized in that: 0.2≤C2≤2.5。 3. The processing method according to claim 1, characterized in that: The reverse osmosis concentrated water includes calcium ions and sulfate ions.

4. The processing method according to claim 1, characterized in that: The antiscalant remover includes any one or more of polyaluminium chloride, polyferric sulfate and ferric chloride.

5. The processing method according to claim 1, characterized in that: The coagulant aid includes polyacrylamide.

6. The processing method according to any one of claims 1 to 5, characterized in that: The treatment method utilizes a reverse osmosis concentrated water crystallization system for crystallization, wherein the reverse osmosis concentrated water crystallization system comprises a water inlet pipeline (1), a crystallization device (2) and a dosing system (3); The crystallization device (2) comprises an outer cylinder (21), a flow guide cylinder (22), a water inlet (23), a water outlet (24) and a stirrer (25); the flow guide cylinder (22) is arranged inside the outer cylinder (21) and is a structure with upper and lower ends open; the water inlet (23) is arranged on the outer cylinder (21) and leads to the lower end of the flow guide cylinder (22); the water outlet (24) is arranged at the upper end of the outer cylinder (21); the stirrer (25) is arranged at the lower end of the outer cylinder (21) and extends into the interior of the flow guide cylinder (22); The water inlet pipe (1) is connected to the water inlet (23) of the crystallization device (2) and is used to pass reverse osmosis concentrated water into the crystallization device (2); The dosing system (3) comprises a first dosing device (31) and a second dosing device (32), wherein the first dosing device (31) is used for dosing a scale inhibitor and remover, and a dosing point is located in a guide tube (22) of the crystallization device (2); and the second dosing device (32) is used for dosing a coagulant, and a dosing point is located between the guide tube (22) and the outer tube (21) of the crystallization device (2).

7. The processing method according to claim 6, characterized in that: The water inlet pipe (1) is provided with a water inlet flow meter (11) and a water inlet conductivity meter (12); A water outlet turbidity meter (26) is provided at the water outlet (24) of the crystallization device (2); A first dosing flow meter (33) is provided in a pipeline from the first dosing device (31) to the crystallization device (2); A second dosing flow meter (34) is provided in the pipeline from the second dosing device (32) to the crystallization device (2); The reverse osmosis concentrated water crystallization system further comprises a PLC control module (4) for monitoring the detection results of the inlet flow meter (11), the inlet conductivity meter (12), the outlet turbidity meter (26), the first dosing flow meter (33) and the second dosing flow meter (34), and dynamically controlling the first dosing device (31) and the second dosing device (32) to add reagents to the crystallization device (2) and adjust the dosing flow rate based on the detection results.

8. The processing method according to claim 7, characterized in that: The processing method comprises the following steps: The reverse osmosis concentrate is introduced into the guide tube (22) through the water inlet pipe (1). Under the action of stirring, the reverse osmosis concentrate flows from bottom to top in the guide tube (22) and overflows into the outer tube (21) to form a cycle. The PLC control module (4) dynamically controls the first dosing device (31) to add a scale inhibitor and remover according to the detection results of the water inlet flow meter (11) and the water inlet conductivity meter (12), and dynamically controls the second dosing device (32) to add a coagulant according to the detection results of the water inlet flow meter (11) and the water outlet turbidity meter (26). When the water outlet hardness and turbidity meet the standards, purified water is obtained.

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