Ion exchange still, wastewater treatment device, and method for treating wastewater containing heavy metals

Abstract

The present application relates to the technical field of chemical wastewater treatment, and provides an ion exchange kettle, a wastewater treatment device and a treatment method for wastewater containing heavy metals, the ion exchange kettle comprises a kettle body and a resin cage detachably arranged in the kettle body, the resin cage is filled with ion exchange resin, mesh holes are arranged on the side of the resin cage, and the diameters of the mesh holes are smaller than the diameters of the ion exchange resin; a wastewater inlet and a regeneration liquid inlet are arranged at the bottom of the kettle body, and a wastewater outlet and a regeneration liquid outlet are arranged at the top of the kettle body, the resin cage of the ion exchange kettle is filled with ion exchange resin to adsorb heavy metals, when the resin is replaced, the resin cage can be taken out from the ion exchange kettle, and then the ion exchange resin can be taken out from the resin cage for replacement, and the whole process does not require personnel to directly contact the resin, so that the operation is safe and convenient.

Description

Technical Field

[0001] This invention relates to the technical field of chemical wastewater treatment, specifically to an ion exchange vessel, a wastewater treatment device, and a method for treating wastewater containing heavy metals. Background Technology

[0002] The principle of ion exchange for removing heavy metals from wastewater is to utilize ion exchange resins containing active functional groups to exchange with heavy metal ions in the wastewater, thereby achieving the recovery of heavy metal ions. It is evident that the core of ion exchange technology is the ion exchange resin. Currently, there are many ion exchange resin products available for wastewater treatment. Unlike chemical precipitation methods, the biggest advantage of ion exchange resins is the generation of less hazardous waste. The recovered heavy metal ions can be reused after returning to their ionic state through regeneration liquid, and the exchange resin itself can be reused after regeneration treatment. These advantages make ion exchange technology highly prominent in the treatment of wastewater containing heavy metals.

[0003] Those skilled in the art have conducted extensive research on the treatment of heavy metal-containing wastewater using ion exchange resins:

[0004] Patent CN114105276A relates to a method for separating cobalt and nickel from wastewater based on ion exchange technology, and patent CN106830435B relates to a method for treating mercury-containing wastewater using ion exchange resin.

[0005] While these patents propose process routes for removing heavy metals from wastewater, they do not propose designs for wastewater treatment devices.

[0006] Those skilled in the art have conducted extensive research on the regeneration of ion exchange resins:

[0007] Patent CN110252428A discloses a device for regenerating and cleaning ion exchange resins. Its washing method is highly effective, and the resin can be easily transferred after cleaning. However, the resin transfer process requires manual labor, and the regenerated solution and chemicals adsorbed on the resin may be harmful to human health. Operators coming into contact with the resin during the transfer process inevitably poses a certain health risk.

[0008] Patent CN113058662A describes a resin regeneration method and a mixed-bed regeneration system, which details the resin regeneration process.

[0009] Patent 201910248885.X proposes a mixed-bed regeneration method for ion exchange resins.

[0010] Patent 202011232803.1 provides an improved mixed-bed regeneration process, system, and application.

[0011] Those skilled in the art have studied the pretreatment process of wastewater before the application of ion exchange resins:

[0012] Patent CN113800704A utilizes reverse osmosis devices, steam generators, etc. to pretreat wastewater before using ion exchange devices for further treatment.

[0013] Currently, wastewater treatment equipment based on ion exchange technology mainly has the following characteristics: the system consists of one or more packed towers filled with ion exchange resin; wastewater and regenerated liquid are tested after passing through the packed tower, and generally no circulation device is provided; the exchange resin is loaded or discharged through the reactor inlet; in existing co-current reactor designs, wastewater and regenerated liquid flow naturally down the bed under their own gravity. These devices and their working mechanisms have some drawbacks:

[0014] 1) Some ion exchange resin water treatment devices cannot regenerate the resin. The regeneration process requires removing the resin, which is time-consuming and labor-intensive, and is not conducive to industrial applications.

[0015] 2) Insufficient resin utilization: The contact time between the resin and wastewater is limited, and the exchange capacity is not fully utilized;

[0016] 3) During the resin replacement process, operators must come into contact with materials containing heavy metals;

[0017] 4) Wastewater containing heavy metals must be tested to determine the concentration of heavy metal ions in the wastewater before a decision can be made on whether to discharge it. This inevitably involves a wastewater testing process. If the working mechanism of the treatment equipment is unreasonable, the equipment may stop working during the wastewater testing process, affecting the overall treatment efficiency.

[0018] 5) No assessment mechanism for the working exchange capacity of the resin has been established. The working exchange capacity of the ion exchange resin decreases with the number of uses throughout the application process. If the resin exchange capacity is insufficient during the application process and the heavy metal content of the wastewater does not meet the discharge standards, all operations need to be repeated, affecting the overall treatment efficiency.

[0019] Suspended particulate matter is a common component of wastewater. Because ion exchange resins are easily affected by suspended particulate matter, some technical solutions use adsorption materials such as activated carbon to pre-treat the wastewater. However, heavy metal ions can also be adsorbed onto these adsorption materials, turning them into difficult-to-treat hazardous waste. Some wastewater treatment processes utilize flocculants or precipitants to remove suspended solids, but these methods can cause secondary pollution to the wastewater and affect the resin's function.

[0020] Based on the patent survey above, there is currently no complete treatment solution or supporting equipment design for wastewater containing suspended particulate matter and heavy metal ions generated in the chemical production field. Summary of the Invention

[0021] The purpose of this invention is to overcome the cumbersome process of resin replacement in the prior art, and the risk of contact with heavy metals during manual removal, which poses a health hazard. This invention provides an apparatus and method for treating wastewater containing heavy metals. The apparatus and method can remove the resin cage from the ion exchange vessel, and then remove the ion exchange resin from the resin cage for replacement. The entire process does not require direct contact with the resin, making the operation safe and convenient.

[0022] To achieve the above objectives, the present invention provides an ion exchange vessel, which includes a vessel body and a resin cage detachably disposed within the vessel body. The resin cage is filled with ion exchange resin, and the resin cage has mesh openings on its periphery, the diameter of which is smaller than the diameter of the ion exchange resin. The bottom of the vessel body is provided with a wastewater inlet and a regenerated liquid inlet, and the top of the vessel body is provided with a wastewater outlet and a regenerated liquid outlet.

[0023] Preferably, the bottom of the vessel is provided with a gas outlet and a residual liquid outlet, the top of the vessel is provided with a gas inlet for introducing gas, and the side wall of the vessel is provided with a pure water inlet for introducing pure water.

[0024] Preferably, a gas distributor is provided inside the reactor above the resin cage.

[0025] Preferably, the resin cage outer sleeve is provided with a plurality of rubber sealing rings.

[0026] Preferably, the volume of the ion exchange resin in the resin cage after absorbing water accounts for 90% to 95% of the total volume of the reactor body.

[0027] Preferably, the outer wall of the vessel is provided with several pressure relief channels along the vertical direction, the pressure relief channels are connected to the pressure relief liquid collector located on the outside, and the top of the vessel is also provided with a safety valve.

[0028] Preferably, the resin cage has several arc-shaped grooves extending vertically and closed at the bottom around its periphery; the resin cage has an axially extending exhaust channel in the middle, and the bottom of the vessel body is provided with a stopcock that can open or close the bottom of the exhaust channel.

[0029] A second aspect of the present invention provides a wastewater treatment device, the wastewater treatment device including an ion exchange vessel, a regenerated liquid storage tank and a plurality of wastewater storage tanks, the regenerated liquid storage tank being connected to the regenerated liquid inlet and the regenerated liquid outlet through a first circulation pipeline, and the wastewater storage tank being connected to the wastewater inlet and the wastewater outlet through a second circulation pipeline.

[0030] Preferably, the wastewater treatment device further includes a regenerated liquid treatment tank, which is connected to the regenerated liquid storage tank and is used to temporarily store the regenerated liquid after use.

[0031] A third aspect of the present invention provides a method for treating wastewater containing heavy metals, the method using a wastewater treatment device, comprising the following steps:

[0032] S1, the wastewater is pretreated and then injected into the wastewater storage tank;

[0033] S2, the wastewater in the wastewater storage tank is circulated between the wastewater storage tank and the ion exchange vessel through the second circulation pipeline;

[0034] S3, sample and analyze the wastewater in the wastewater storage tank, and discharge the wastewater in the wastewater storage tank after the wastewater meets the preset requirements;

[0035] S4, dry compressed gas is introduced into the ion exchange vessel through the air inlet located at the top of the vessel body to discharge residual wastewater into the wastewater storage tank;

[0036] S5, pure water is introduced into the ion exchange vessel through the pure water inlet provided on the side wall of the vessel body and soaked for a preset time, and then the pure water is discharged through the residual liquid outlet provided at the bottom of the vessel body.

[0037] S6, dry compressed air is introduced into the ion exchange vessel through the air inlet to purge the ion exchange resin;

[0038] S7, the regenerated liquid in the regenerated liquid storage tank is circulated between the ion exchange vessel and the regenerated liquid storage tank through the first circulation pipeline;

[0039] S8, the regenerated liquid in the regenerated liquid storage tank is introduced into the regenerated liquid treatment tank;

[0040] S9, dry compressed gas is introduced into the ion exchange vessel through the air inlet to discharge the residual regenerated liquid into the regenerated liquid storage tank;

[0041] S10, pure water is introduced into the ion exchange vessel through the pure water inlet and soaked for a preset time, and then the pure water is discharged through the residual liquid outlet;

[0042] S11, dry compressed air is introduced into the ion exchange vessel through the air inlet to purge the ion exchange resin;

[0043] S12, inject new regenerated liquid into the regenerated liquid storage tank.

[0044] It is easy to see from the above technical solution that the advantages of the present invention are:

[0045] 1. The resin cage of the ion exchange vessel provided by the present invention is filled with ion exchange resin to adsorb heavy metals. When the resin is replaced, the resin cage can be taken out from the ion exchange vessel, and then the ion exchange resin can be taken out from the resin cage for replacement. The entire process does not require personnel to directly contact the resin, and the operation is safe and convenient.

[0046] 2. The wastewater treatment device provided by this invention is equipped with a dual circulation system consisting of a first circulation pipeline and a second circulation pipeline. In this way, when the treated wastewater returns to the wastewater storage tank and the heavy metal concentration is tested to see if it meets the standard, the ion exchange vessel can perform resin regeneration, avoiding intermittent start-up and shutdown of the entire device and improving the overall operating efficiency. The design of multiple wastewater storage tanks allows the wastewater in each wastewater storage tank to be treated immediately one by one without waiting for the test results of the previous wastewater treatment, further improving the operating efficiency. Attached Figure Description

[0047] Figure 1 This is a schematic diagram of an overall device of a preferred embodiment of a wastewater treatment device;

[0048] Figure 2 This is a schematic diagram of a preferred embodiment of an ion exchange reactor;

[0049] Figure 3 This is a schematic diagram of pressure control in a preferred embodiment of an ion exchange reactor;

[0050] Figure 4 This is a schematic diagram of a preferred embodiment of the bottom of an ion exchange vessel;

[0051] Figure 5 This is a flowchart of a preferred embodiment of a method for treating wastewater containing heavy metals.

[0052] Explanation of reference numerals in the attached figures

[0053] 1. Reactor body; 101. Air inlet; 102. Pure water inlet; 103. Plug; 104. Pressure relief channel; 105. Safety valve; 106. Residual liquid outlet; 107. Air outlet; 108. Gas distributor; 2. Resin cage; 201. Arc-shaped groove; 202. Exhaust channel; 3. Rubber sealing ring; 4. Regenerated liquid storage tank; 5. First circulation pipeline; 501. Regenerated liquid inlet; 502. Regenerated liquid outlet; 6. Wastewater storage tank; 7. Second circulation pipeline; 701. Wastewater inlet; 702. Wastewater outlet; 8. Pressure relief liquid collector; 9. Regenerated liquid treatment tank. Detailed Implementation

[0054] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0055] In this invention, unless otherwise stated, directional terms such as "up, down, left, right, front, back, inside, outside" in the terminology only represent the orientation of the term in its normal use or are common terms understood by those skilled in the art, and should not be regarded as a limitation on the term.

[0056] See Figure 1 The present invention provides an ion exchange vessel, which includes a vessel body 1 and a resin cage 2 detachably disposed within the vessel body 1. The resin cage 2 is filled with ion exchange resin, and the resin cage 2 has mesh openings on its periphery, the mesh diameter being smaller than the diameter of the ion exchange resin. The bottom of the vessel body 1 is provided with a wastewater inlet 701 and a regenerated liquid inlet 501, and the top of the vessel body 1 is provided with a wastewater outlet 702 and a regenerated liquid outlet 502.

[0057] The resin cage 2 of the present invention is filled with ion exchange resin to adsorb heavy metals. When the resin is replaced, the resin cage 2 can be taken out from the vessel body 1, and then the ion exchange resin can be taken out from the resin cage 2 for replacement. The entire process does not require personnel to directly contact the resin, making the operation safe and convenient.

[0058] It is worth noting that there are multiple ways to remove the ion exchange resin in this embodiment. For example, an opening can be made at the bottom of the resin cage 2 (and then sealed with a cover plate when filling the resin) to pour out the ion exchange resin. Those skilled in the art should be able to come up with more suitable and reasonable methods, all of which should be within the protection scope of this invention.

[0059] In addition, there are several ways to remove the resin cage 2 from the ion exchange vessel. For example, an opening can be provided at the top of the ion exchange vessel to lift the resin cage 2 out as a whole. This will not be elaborated further.

[0060] In addition, specifically, it is best if the mesh diameter is 2 to 3 mm smaller than the diameter of the ion exchange resin.

[0061] For other implementation methods, please refer to [link / reference]. Figure 1 The resin cage 2 is covered with several rubber sealing rings 3.

[0062] As before, the resin cage 2 needs to be placed or removed from the ion exchange vessel as a whole. Therefore, a certain gap needs to be reserved between the resin cage 2 and the inner wall of the ion exchange vessel. The width of the several rubber sealing rings 3 on the outer sleeve of the resin cage 2 should be slightly smaller than the gap width. After the resin cage 2 is placed into the ion exchange vessel, hot air can be blown in to expand the rubber sealing rings 3, which will fill the gap width and ensure the stability of the resin cage 2 in the ion exchange vessel. Before removing the resin cage 2, hot air can also be blown into the ion exchange vessel to soften the rubber sealing rings 3, making it easier to remove the resin cage 2.

[0063] In addition, the material of the rubber sealing ring 3 can be selected from HNBR hydrogenated nitrile butadiene rubber, which has good corrosion resistance, wear resistance and tear resistance.

[0064] In some other embodiments, the bottom of the vessel body 1 is also provided with an air outlet 107 and a residual liquid outlet 106, the top of the vessel body 1 is also provided with an air inlet 101 for introducing gas, and the side wall of the vessel body 1 is provided with a pure water inlet 102 for introducing pure water.

[0065] The ion exchange vessel provided by this invention requires the introduction of gas or liquid for auxiliary operations in many places. For example, the insertion or removal of the resin cage 2 may require the introduction of hot air; the drying of the resin may require the introduction of drying compressed gas; and the cleaning of the residue in the ion exchange vessel may require the introduction of pure water. Generally, the introduced gas is discharged from the gas outlet 107, and the introduced liquid is discharged from the residual liquid outlet 106.

[0066] In some other embodiments, the volume percentage of the ion exchange resin in the resin cage 2 after absorbing water is 90% to 95%.

[0067] To ensure sufficient contact between the resin and the liquid medium and smooth flow of the liquid medium within the resin cage 2, a small amount of space is left for the resin to move around. Specifically, it is best if the volume percentage of the ion exchange resin in the resin cage after absorbing water is 90% to 95%.

[0068] In the foregoing embodiments, please refer to Figure 3 , Figure 3 This is a schematic diagram of the pressure control of the ion exchange vessel of the present invention. Several pressure relief channels 104 are provided on the outer wall of the vessel body 1 along the vertical direction. The pressure relief channels 104 are connected to the pressure relief liquid collector 8 located on the outside. A safety valve 105 is also provided on the top of the vessel body 1.

[0069] As mentioned in the aforementioned embodiments, the ion exchange vessel needs to be circulated with gas for operation, such as by circulating dry compressed gas to dry the ion exchange vessel. However, this will inevitably cause pressure changes inside the ion exchange vessel. In particular, when the resin is under excessive pressure, it will be squeezed together and block the passage of the gas medium. Based on this problem, several pressure relief channels 104 are provided on the outer wall of the ion exchange vessel in conjunction with the safety valve 105 at the top for pressure relief. When the pressure inside the ion exchange vessel is too high, the pressure relief channels 104 can be opened step by step to relieve pressure.

[0070] In the foregoing embodiments, please refer to Figure 2 and Figure 4 , Figure 2 This is a schematic diagram of the horizontal cross-section of the ion exchange vessel of the present invention. Figure 4This is a schematic diagram of the bottom layout of the ion exchange vessel of the present invention. The resin cage 2 is provided with several arc-shaped grooves 201 extending vertically and closed at the bottom around its periphery; the resin cage 2 is provided with an axially extending exhaust channel 202 in the middle, and the bottom of the vessel body 1 is provided with a stopcock 103 that can open or close the bottom of the exhaust channel 202.

[0071] When the ion exchange vessel is conditioned by a gaseous medium, such as a dry compressed gas, the following example uses a dry compressed gas. The dry compressed gas is distributed by a distributor to each arc-shaped groove 201. The dry compressed gas enters the resin cage 2 from the arc-shaped groove 201 and passes through the resin, carrying the water vapor in it into the exhaust channel 202 and finally exiting from the outlet 107 of the ion exchange vessel. The resin can fully contact the dry compressed air, avoiding the awkward situation where the gas enters directly from the top, the center of the resin is impacted, and the edges are difficult to fully contact with the gas. During the removal of heavy metal ions and regeneration, the stopcock 103 tightly seals the bottom of the exhaust channel 202, preventing the liquid medium from bypassing the resin and directly reaching the top of the exhaust channel 202 for discharge. Similarly, the stopcock 103 can also be opened as needed, such as during the aforementioned drying operation.

[0072] Another aspect of the present invention provides a wastewater treatment device, which includes an ion exchange vessel, a regenerated liquid storage tank 4, and several wastewater storage tanks 6. The regenerated liquid storage tank 4 is connected to a regenerated liquid inlet 501 and a regenerated liquid outlet 502 through a first circulation pipeline 5, and the wastewater storage tanks 6 are connected to a wastewater inlet 701 and a wastewater outlet 702 through a second circulation pipeline 7.

[0073] When treating wastewater, a circulating pump circulates the wastewater between the wastewater storage tank 6 and the ion exchange vessel through the second circulating pipeline 7. During resin regeneration, another circulating pump circulates the regenerated liquid between the regenerated liquid storage tank 4 and the ion exchange vessel through the first circulating pipeline 5. In this way, when the treated wastewater returns to the wastewater storage tank 6 and the heavy metal concentration is tested to see if it meets the standard, the ion exchange vessel can perform resin regeneration, avoiding intermittent start-up and shutdown of the entire device and improving the overall operating efficiency. The design of multiple wastewater storage tanks 6 allows the wastewater in each wastewater storage tank 6 to be treated immediately one by one without waiting for the test results of the previous wastewater treatment, further improving the operating efficiency.

[0074] When wastewater or regenerated liquid is introduced, the liquid medium enters from the bottom of the ion exchange vessel, passes through the resin cage 2 and the ion exchange resin inside, so that the resin can be completely immersed in the liquid medium. The liquid medium eventually overflows from the top of the ion exchange vessel. With this setting, the resin can fully contact the liquid medium, which will significantly improve both the removal of heavy metal ions and the regeneration effect.

[0075] Specifically, the flow rate of the liquid medium should be such that it can achieve turbulence when entering the ion exchange vessel. This can be calculated based on the pipeline data, and the circulation time should be 20 to 30 minutes.

[0076] In the foregoing embodiments, please refer to Figure 1 It also includes a regenerated liquid treatment tank 9, which is connected to the regenerated liquid storage tank 4.

[0077] The regeneration solution treatment tank 9 is used to temporarily store the used regeneration solution and perform operations such as heavy metal ion concentration measurement. The solution can then be reused in chemical production.

[0078] In another aspect, the present invention provides a method for treating wastewater containing heavy metals, please refer to [reference needed]. Figure 5 , Figure 5 This is a flowchart of the method for treating heavy metal-containing wastewater according to the present invention, the method comprising:

[0079] S1: After pretreatment, the wastewater is injected into the wastewater storage tank 6;

[0080] The pretreatment here is mainly used to remove suspended particulate matter from wastewater and perform pH adjustment and other operations. The preferred methods for removing suspended particulate matter are precision filtration or air flotation.

[0081] S2: The wastewater in the wastewater storage tank 6 is circulated between the wastewater storage tank 6 and the ion exchange vessel through the second circulation pipeline 7;

[0082] At this point, the stopcock 103 needs to be tightly sealed to the bottom of the exhaust channel 202 to prevent wastewater from bypassing the resin and directly reaching the top of the exhaust channel 202 for discharge.

[0083] S3: Sampling and analyzing the wastewater, and discharging the wastewater from wastewater storage tank 1 after it meets the preset requirements;

[0084] S4: Dry compressed gas is introduced into the ion exchange vessel through the air inlet 101 located at the top of the vessel body 1 to discharge residual wastewater into the wastewater storage tank 6;

[0085] At this time, the circulation pump of the second circulation pipeline 7 is turned off, but the residual liquid outlet 106 is opened to facilitate the discharge of the residue into the wastewater storage tank 6.

[0086] S5: Pure water is introduced into the ion exchange vessel through the pure water inlet 102 set on the side wall of the vessel body 1 and soaked for a preset time, and then the pure water is discharged through the residual liquid outlet 106 set at the bottom of the vessel body 1.

[0087] Here, pure water is used to soak the resin in order to remove the residual wastewater between the resins.

[0088] S6: Purge the ion exchange resin with dry compressed air inside the ion exchange vessel;

[0089] The resin is dried, and the purging time should not be too long, otherwise it will cause the resin to crack. Preferably, the purging time is 5 to 10 minutes. If necessary, the pressure relief channel 104 can be opened in conjunction with the safety valve 105 to relieve pressure.

[0090] S7: The regenerated liquid in the regenerated liquid storage tank 4 is circulated between the ion exchange vessel and the regenerated liquid storage tank 4 through the first circulation pipeline 5;

[0091] At this point, the stopcock 103 needs to be tightly sealed to the bottom of the exhaust channel 202 to prevent the regenerated liquid from bypassing the resin and directly reaching the top of the exhaust channel 202 for discharge.

[0092] S8: Pass the regenerated liquid in the regenerated liquid storage tank 4 into the regenerated liquid treatment tank 9;

[0093] The regeneration solution treatment tank 9 can temporarily store the used regeneration solution and perform operations such as heavy metal ion concentration measurement. The solution can then be reused in chemical production.

[0094] S9: Dry compressed gas is introduced into the ion exchange vessel through the air inlet 101 to discharge the residual regenerated liquid into the regenerated liquid storage tank 4;

[0095] At this time, the circulation pump of the first circulation pipeline 5 is turned off, but the residual liquid outlet 106 is opened to facilitate the discharge of the residue into the regenerated liquid storage tank 4.

[0096] S10: Pure water is introduced into the ion exchange vessel through the pure water inlet 102 and soaked for a preset time, and then the pure water is discharged through the residual liquid outlet 106.

[0097] Here, pure water is used to soak the resin in order to remove the residual regeneration solution between the resins.

[0098] S11: Dry compressed air is introduced into the ion exchange vessel through the air inlet 101 to purge the ion exchange resin.

[0099] The precautions for purging are the same as those in step S6 above.

[0100] S12: Inject new regenerated liquid into the regenerated liquid storage tank 4.

[0101] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0102] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0103] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A method for treating wastewater containing heavy metals, characterized in that, The treatment method uses a wastewater treatment device, which includes an ion exchange vessel, a regenerated liquid storage tank (4), and several wastewater storage tanks (6). The ion exchange vessel includes a vessel body (1) and a resin cage (2) detachably disposed within the vessel body (1). The resin cage (2) is filled with ion exchange resin, and the resin cage (2) has mesh openings on its periphery, with the mesh diameter being smaller than the diameter of the ion exchange resin. The bottom of the vessel body (1) is provided with a wastewater inlet (701) and a regenerated liquid inlet (501), and the top of the vessel body (1) is provided with a wastewater outlet (702) and a regenerated liquid outlet (502). The regenerated liquid storage tank (4) is connected to the regenerated liquid inlet (501) and the regenerated liquid outlet (502) through a first circulation pipeline (5), and the wastewater storage tank (6) is connected to the wastewater inlet (701) and the wastewater outlet (702) through a second circulation pipeline (7). The treatment method includes the following steps: S1, the wastewater is pretreated and then injected into the wastewater storage tank (6). S2, the wastewater in the wastewater storage tank (6) is circulated between the wastewater storage tank (6) and the ion exchange vessel through the second circulation pipeline (7); S3, take samples of the wastewater in the wastewater storage tank (6) for analysis, and discharge the wastewater in the wastewater storage tank (6) after the wastewater meets the preset requirements; S4, dry compressed gas is introduced into the ion exchange vessel through the air inlet (101) set at the top of the vessel body (1) to discharge the residual wastewater into the wastewater storage tank (6); S5, pure water is introduced into the ion exchange vessel through the pure water inlet (102) set on the side wall of the vessel body (1) and soaked for a preset time, and then the pure water is discharged through the residual liquid outlet (106) set at the bottom of the vessel body (1); S6, dry compressed air is introduced into the ion exchange vessel through the air inlet to purge the ion exchange resin; S7, the regenerated liquid in the regenerated liquid storage tank (4) is circulated between the ion exchange vessel and the regenerated liquid storage tank (4) through the first circulation pipeline (5); S8, the regenerated liquid in the regenerated liquid storage tank (4) is introduced into the regenerated liquid treatment tank (9). S9, dry compressed gas is introduced into the ion exchange vessel through the air inlet (101) to discharge the residual regenerated liquid into the regenerated liquid storage tank (4); S10, pure water is introduced into the ion exchange vessel through the pure water inlet (102) and soaked for a preset time, and then the pure water is discharged through the residual liquid outlet (106); S11, dry compressed air is introduced into the ion exchange vessel through the air inlet (101) to purge the ion exchange resin; S12, inject new regenerated liquid into the regenerated liquid storage tank (4).

2. The method for treating heavy metal-containing wastewater according to claim 1, characterized in that, The wastewater treatment device also includes a regenerated liquid treatment tank (9), which is connected to the regenerated liquid storage tank (4) and is used to temporarily store the regenerated liquid after use.

3. An ion exchange vessel, characterized in that, The ion exchange vessel is configured for treating heavy metal-containing wastewater according to claim 1. The ion exchange vessel includes a vessel body (1) and a resin cage (2) detachably disposed within the vessel body (1). The resin cage (2) is filled with ion exchange resin. The resin cage (2) has mesh openings on its periphery, and the diameter of the mesh openings is smaller than the diameter of the ion exchange resin. The bottom of the vessel body (1) is provided with a wastewater inlet (701) and a regenerated liquid inlet (501), and the top of the vessel body (1) is provided with a wastewater outlet (702) and a regenerated liquid outlet (502). The bottom of the vessel body (1) is also provided with an air outlet (107) and a residual liquid outlet (106), and the top of the vessel body (1) is also provided with an air inlet (101) for introducing gas. A gas distributor (108) is provided inside the vessel body (1) above the resin cage (2), and several pressure relief channels (104) are provided on the outer wall of the vessel body (1) in the vertical direction. The resin cage (2) has several arc-shaped grooves (201) extending vertically and closed at the bottom on its periphery, and each arc-shaped groove (201) is connected to the gas distributor (108); the resin cage (2) has an axially extending exhaust channel (202) in the middle, and the exhaust channel (202) is connected to the gas outlet (107); the bottom of the vessel body (1) is provided with a stopcock (103) that can open or close the bottom of the exhaust channel (202).

4. The ion exchange vessel according to claim 3, characterized in that, The side wall of the vessel (1) is provided with a pure water inlet (102) for introducing pure water.

5. The ion exchange vessel according to claim 3, characterized in that, The resin cage (2) is covered with several rubber sealing rings (3).

6. The ion exchange vessel according to claim 3, characterized in that, The volume of the ion exchange resin in the resin cage (2) after absorbing water accounts for 90% to 95% of the total volume of the vessel body (1).

7. The ion exchange vessel according to claim 3, characterized in that, The pressure relief channel (104) is connected to the external pressure relief fluid collector (8), and a safety valve (105) is also provided on the top of the vessel body (1).

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