Adsorption and regeneration system of ix resin and adsorption and regeneration method of ix resin

Abstract

This invention provides an adsorption and regeneration system and method for IX resin, which can recycle regenerated liquid to regenerate the IX resin. The IX resin adsorption and regeneration system includes: an IX resin adsorption unit, through which water containing perfluorinated and polyfluoroalkyl substances (PFAS) flows to adsorb the PFAS using the IX resin; a regenerated liquid circulation path for circulating regenerated liquid to the IX resin adsorption unit, the regenerated liquid being used to desorb PFAS from the IX resin; the regenerated liquid circulation path includes: a regenerated liquid tank for storing the regenerated liquid and receiving the regenerated liquid discharged from the IX resin adsorption unit; a regenerated liquid treatment unit for performing NTP treatment on the PFAS-containing regenerated liquid, in which low-temperature plasma (NTP) is generated by discharge to degrade the PFAS in the regenerated liquid; and a regenerated liquid conditioning unit for conditioning the NTP-treated regenerated liquid to restore its ability to desorb PFAS before feeding it back into the IX resin adsorption unit.

Description

Technical Field

[0001] This invention relates to an adsorption and regeneration system and method for IX resin, and particularly to a system and method for regenerating and recycling saturated IX resin after adsorbing PFAS using IX resin. Background Technology

[0002] Currently, PFAS (Per- and Poly-fluoroalkyl Substances) are widely used in industrial and consumer products such as fire-fighting foams, non-stick coatings, and waterproof fabrics. However, PFAS have extremely strong chemical stability and environmental durability, and their environmental emissions have caused global water pollution.

[0003] Anion exchange resins (IX resins) have fixed positively charged quaternary ammonium groups, amino groups or other anion exchange sites, which can selectively enrich a variety of PFAS molecules through electrostatic interaction, ion exchange interaction and hydrophobic interaction. They are generally superior to granular activated carbon, especially in the removal of short-chain PFAS.

[0004] In existing projects, IX resin is often operated in a fixed-bed configuration, employing single-column, dual-column series connection, multi-column parallel connection, or multi-column alternating modes. After IX resin adsorption saturation, traditional treatment methods mainly include resin replacement, external incineration, chemical regeneration, and external disposal of the regenerated liquid.

[0005] However, replacing or disposing of saturated IX resin is costly and generates PFAS-containing solid waste. While chemical regeneration can restore some adsorption capacity, it typically only transfers PFAS from the resin phase to the regeneration solution, bottom residue, or other concentrated residues, without actually destroying PFAS within the regeneration system. Subsequent distillation, incineration, plasma treatment, or other methods are still required.

[0006] When external disposal of regenerated liquid is required, it not only increases the amount of waste liquid and back-end costs, but also the high concentration and complex composition of PFAS regenerated liquid mean that the regeneration of IX resin and the destruction of PFAS are disconnected through external disposal, resulting in high engineering operating costs and environmental responsibility. Summary of the Invention

[0007] To address the aforementioned problems, this invention proposes an adsorption and regeneration system and method for IX resin, which can recycle the regeneration liquid to regenerate the IX resin, reduce the amount of regeneration liquid discharged, restore the adsorption capacity of the IX resin, reduce the back-end treatment load of PFAS, and improve the continuous operation capability of the system.

[0008] The IX resin adsorption and regeneration system includes:

[0009] The IX resin adsorption unit is used to adsorb water containing perfluorinated and polyfluoroalkyl substances (PFAS).

[0010] A regenerated liquid circulation path is used to circulate regenerated liquid to the IX resin adsorption unit, the regenerated liquid being used to desorb PFAS from the IX resin.

[0011] The regenerated liquid circulation path includes:

[0012] A regeneration tank, which stores regeneration liquid and receives regeneration liquid discharged from the IX resin adsorption unit;

[0013] The regenerated liquid treatment unit performs NTP treatment on the PFAS-containing regenerated liquid. In the NTP treatment, low-temperature plasma, i.e., NTP, is generated by discharge to degrade the PFAS in the regenerated liquid.

[0014] The regenerated liquid conditioning unit conditions the regenerated liquid after NTP treatment to restore its ability to desorb PFAS, and then feeds it into the IX resin adsorption unit.

[0015] In some embodiments, in the regenerated liquid circulation path, the regenerated liquid treatment unit is an NTP treatment unit located downstream of the regeneration tank. The NTP treatment unit receives PFAS-containing regenerated liquid from the regenerated liquid tank and sends the NTP-treated regenerated liquid to the regenerated liquid conditioning unit.

[0016] In some embodiments, the regenerated liquid treatment unit is disposed within the IX resin adsorption unit.

[0017] In the IX resin adsorption unit, after PFAS is desorbed by the regenerated liquid, NTP is generated by discharge to degrade the PFAS in the regenerated liquid.

[0018] In some embodiments, the outer shell of the IX resin adsorption unit is connected to a grounding electrode, and a high-voltage electrode is inserted inside the IX resin adsorption unit to generate NTP by discharging through the high-voltage electrode.

[0019] In some embodiments, the regenerated liquid conditioning unit includes a defluorination unit for removing or controlling F. - HF, fluorine-containing intermediates.

[0020] In some embodiments, the defluorination unit removes fluoride through one or more of the following methods: precipitation of calcium, magnesium, or aluminum salts, special defluorination adsorbents, anion exchange, membrane separation, and alkaline washing absorption.

[0021] In some embodiments, the regenerated liquid conditioning unit includes a conditioning unit that adjusts at least one of the following: pH, conductivity, ionic strength, redox state, regenerator concentration, and organic additive concentration of the regenerated liquid.

[0022] In some embodiments, the IX resin adsorption and regeneration system includes multiple IX resin adsorption units.

[0023] When regenerant is introduced into one IX resin adsorption unit, water containing PFAS is allowed to flow into other IX resin adsorption units.

[0024] The adsorption and regeneration method for IX resin of the present invention uses the adsorption and regeneration system for IX resin described in any one of the above claims, and includes the following steps:

[0025] In the adsorption step, water containing perfluorinated and polyfluoroalkyl substances, i.e., PFAS, is passed through the IX resin adsorption unit, and the PFAS are adsorbed by the IX resin.

[0026] The saturation detection step involves detecting the operating status of the IX resin adsorption unit to determine whether the IX resin is saturated.

[0027] Switch the operating steps, stop the inflow of PFAS-containing water into the IX resin adsorption unit, and introduce regeneration solution;

[0028] The NTP regeneration step utilizes the regenerated solution to desorb PFAS from the IX resin.

[0029] The effect evaluation step assesses the regeneration effect of the IX resin and determines whether the regeneration effect of the IX resin is qualified.

[0030] The operation is restored by resuming the flow of PFAS-containing water into the IX resin adsorption unit after determining that the regeneration effect of the IX resin is qualified.

[0031] In some embodiments, during the NTP regeneration step, PFAS in the regenerated liquid are degraded by a regenerated liquid treatment unit, and the ability of the regenerated liquid to desorb PFAS from the IX resin is restored by a regenerated liquid conditioning unit.

[0032] In some embodiments, the volume of regenerated liquid introduced into the IX resin is 0.5 BV to 5 BV. More preferably, the volume of regenerated liquid introduced into the IX resin is 0.5 BV to 2 BV.

[0033] In some embodiments, during the effect evaluation step, the regeneration effect of the IX resin is deemed satisfactory when the regeneration efficiency is above 80%.

[0034] The regeneration efficiency is the ratio of the adsorption capacity of the regenerated IX resin to the initial adsorption capacity of the IX resin. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the adsorption and regeneration system of IX resin according to the first embodiment of the present invention.

[0036] Figure 2 This is a flowchart of the adsorption and regeneration method of IX resin according to the first embodiment of the present invention.

[0037] Figure 3 This is a structural diagram of the IX resin adsorption unit in the IX resin adsorption and regeneration system of the second embodiment of the present invention. Detailed Implementation

[0038] Specific embodiments of this disclosure will now be described with reference to the accompanying drawings. It should be understood that the following description is for the purpose of enabling those skilled in the art to quickly understand the contents of this disclosure and is not intended to limit the scope of protection claimed by this disclosure. By reading the following detailed description in conjunction with the accompanying drawings, those skilled in the art will be able to more clearly recognize the features and advantages of this disclosure. Unless otherwise stated, the terminology used herein has its common meaning in the art. The term "comprising" as used herein is open-ended, meaning it does not exclude additional, unlisted members or elements. The term "and / or" as used herein includes any and all combinations of the listed members or elements.

[0039] [First Implementation Method]

[0040] Figure 1 This is a schematic diagram of the adsorption and regeneration system of IX resin according to the first embodiment of the present invention.

[0041] like Figure 1 As shown, the IX resin adsorption and regeneration system 100 includes: an IX resin adsorption unit 101, through which water containing perfluorinated and polyfluoroalkyl substances (PFAS) flows to adsorb the PFAS using the IX resin; a regeneration liquid circulation path, which circulates regeneration liquid to the IX resin adsorption unit, the regeneration liquid being used to desorb PFAS from the IX resin; the regeneration liquid circulation path includes: a regeneration liquid tank 102, which stores the regeneration liquid and receives the regeneration liquid discharged from the IX resin adsorption unit; a regeneration liquid treatment unit 104, which performs NTP treatment on the PFAS-containing regeneration liquid, in which low-temperature plasma (NTP) is generated by discharge to degrade the PFAS in the regeneration liquid; and a regeneration liquid conditioning unit 105, which conditions the NTP-treated regeneration liquid to restore its ability to desorb PFAS and then feeds it into the IX resin adsorption unit 101.

[0042] The aforementioned IX resin adsorption and regeneration system 100 enables the desorption of PFAS from the resin phase to the regeneration liquid phase within the IX resin adsorption unit using the regeneration liquid. The regeneration liquid, containing PFAS, undergoes chain breaking, defluorination, and degradation treatment via a regeneration liquid circulation path. After defluorination and liquid conditioning, it is reused in the IX resin regeneration process. This reduces the amount of regeneration liquid discharged, restores the IX resin adsorption capacity, decreases the PFAS downstream disposal load, and improves the system's continuous operation capability.

[0043] Furthermore, by continuously reducing the PFAS concentration in the circulating regenerated liquid, the desorption concentration gradient from the resin phase to the regenerated liquid phase can be maintained, allowing PFAS to continuously migrate from the resin phase to the regenerated liquid phase. Compared with the simple chemical regeneration in existing technologies, this not only restores the resin adsorption sites but also enables the degradation and defluorination control of PFAS within the system.

[0044] Next, the various parts of the IX resin adsorption and regeneration system 100 will be described in detail.

[0045] In this embodiment, the IX resin adsorption unit 101 can use an IX resin column as the adsorption and regeneration body. When water containing PFAS flows through the IX resin adsorption unit 101, the PFAS is adsorbed by the IX resin column, thereby achieving the removal of PFAS.

[0046] A switching valve is provided on the IX resin adsorption unit 101. When it is determined that the IX resin adsorbs PFAS to saturation, the valve can be switched to allow the regenerated liquid to flow in and start the regenerated liquid circulation.

[0047] The regenerated liquid circulation path serves as a bypass path for the IX resin adsorption unit 101. The regenerated liquid from the IX resin after PFAS desorption in the IX resin adsorption unit 101 is discharged into the regenerated liquid circulation path. After being treated to restore its ability to desorb PFAS from the IX resin, the regenerated liquid is returned to the IX resin adsorption unit 101 for the regeneration of the IX resin. The regenerated liquid may contain inorganic salts, alkalis, a low proportion of alcohol additives, surfactants, or other components that can promote PFAS desorption.

[0048] In this embodiment, a regenerated liquid tank 102, a regenerated liquid treatment unit 104, and a regenerated liquid adjustment unit 105 are provided in the regenerated liquid circulation path. Alternatively, a driving mechanism such as a circulation pump 103 can be provided in the regenerated liquid circulation path to achieve the circulation of the regenerated liquid.

[0049] The regenerated liquid tank 102 is used to contain the regenerated liquid. When the IX resin adsorption unit 101 is operating normally and not regenerating the IX resin, the regenerated liquid in the regenerated liquid circulation path does not circulate but is stored in the regenerated liquid tank 102. In this embodiment, the regenerated liquid tank 102 is located downstream of the IX resin adsorption unit 101 in the regenerated liquid circulation path, thereby receiving the regenerated liquid after PFAS desorption from the IX resin. A regenerated liquid processing unit 104 and a regenerated liquid conditioning unit 105 are provided downstream of the regenerated liquid tank 102, so that the regenerated liquid tank 102 can function as a buffer tank for subsequent processing units. In addition, the position of the regenerated liquid tank 102 is not limited to this and can be adjusted according to actual needs.

[0050] In this embodiment, the regenerated liquid treatment unit 104 is an independent unit disposed in the regenerated liquid circulation path. The regenerated liquid containing PFAS is subjected to NTP treatment in the regenerated liquid treatment unit. In the NTP treatment, low-temperature plasma, i.e., NTP, is generated by discharge, causing the PFAS in the regenerated liquid to undergo chain scission, defluorination, and partial or further mineralization. The effect of NTP treatment can be expressed as the target PFAS reduction rate. More preferably, it combines short-chain intermediates, F... - The evaluation is based on a comprehensive assessment of indicators such as emission amount, TOF / EOF reduction rate, exhaust gas fluorine capture amount, COD change, and energy consumption.

[0051] The regenerated liquid treatment unit 104 can continuously reduce the concentration of target PFAS and extractable organic fluorine in the regenerated liquid, reduce the activity of liquid-phase PFAS, break the desorption equilibrium limitation between the resin phase and the liquid phase, and thus maintain the driving force for the migration of PFAS from the resin phase to the regenerated liquid phase.

[0052] The regenerated liquid after NTP treatment by the regenerated liquid treatment unit 104 can be adjusted by the regenerated liquid adjustment unit 105 to restore the regenerated liquid's ability to desorb PFAS. In this embodiment, the regenerated liquid adjustment unit 105 may include a defluorination unit and a liquid conditioning unit.

[0053] The defluorination unit is used to remove or control F - HF and fluorine-containing intermediates. The defluorination unit can remove fluoride through one or more of the following methods: calcium salt, magnesium salt or aluminum salt precipitation, special defluorination adsorbent, anion exchange, membrane separation, alkaline washing absorption, etc.

[0054] The liquid conditioning unit can adjust at least one of the following: pH, conductivity, ionic strength, redox state, regenerant concentration, and organic additive concentration of the regenerant.

[0055] In addition, when the salinity and F in the regenerated solution -When TOF / EOF, COD, organic additives, or conductivity exceed set thresholds, the control system can control the regenerated liquid adjustment unit 105 to partially discharge the concentrate and add new regenerated liquid or supplementary agent. The discharged concentrate can enter an independent defluorination, solidification, or final disposal unit. After adding fresh regenerated liquid or supplementary agent, closed-loop operation can continue.

[0056] After passing through the regenerated liquid treatment unit 104 and the regenerated liquid conditioning unit 105, the regenerated liquid, which has regained its desorption capacity, can be returned to the IX resin adsorption unit 101 through the regenerated liquid circulation path for PFAS desorption again.

[0057] Furthermore, the adsorption and regeneration system 100 of the IX resin in this embodiment may also include a control system capable of online detection of F. - Parameters such as pH, conductivity, ORP, and PFAS are used to control valves, circulation pumps, NTP power supplies, concentrate discharge, and replenishment.

[0058] Next, refer to Figure 2 The adsorption and regeneration method of IX resin using the adsorption and regeneration system 100 of IX resin is described. Figure 2 This is a flowchart of the adsorption and regeneration method of IX resin according to the second embodiment of the present invention.

[0059] In this embodiment, the adsorption and regeneration method of IX resin can be used in water treatment containing PFAS, including the following steps: adsorption step S1, saturation detection step S2, switching operation step S3, NTP regeneration step S4, effect evaluation step S5, and operation recovery step S6.

[0060] In the adsorption step S1, water containing PFAS is passed through the IX resin adsorption unit 101. The IX resin can selectively enrich various PFAS molecules through electrostatic interactions, ion exchange interactions, and hydrophobic interactions, thereby realizing the adsorption of PFAS by the IX resin.

[0061] In the saturation detection step S2, the operating status of the IX resin adsorption unit 101 is detected to determine whether the IX resin is saturated. In this embodiment, saturation determination can be achieved by PFAS monitoring at the midpoint of the pre-adsorption column-post-protection column dual-tower configuration, bed volume (BV), periodic LC-MS / MS detection, TOF / EOF analysis, and breakthrough model prediction. Additionally, conductivity, pH, pressure difference, and flow rate can also be used as auxiliary indicators of operating status or regenerated liquid replacement status.

[0062] In the saturation detection step S2, once saturation of the IX resin is detected, the process proceeds to the switching operation step S3. In the switching operation step S3, the inflow of PFAS-containing water into the IX resin adsorption unit is stopped, and regeneration solution is introduced.

[0063] Alternatively, in some embodiments, multiple IX resin adsorption units 101 may be provided. During the regeneration of one IX resin adsorption unit 101, PFAS-containing water can flow into other IX resin adsorption units 101 by switching operation step S3. This ensures continuous operation of the entire water treatment system without interruption.

[0064] In the NTP regeneration step S4, PFAS in the IX resin are desorbed using a circulating regenerated liquid. The volume of the regenerated liquid introduced into the IX resin adsorption unit 101 is preferably 0.5 BV to 5 BV, more preferably 0.5 BV to 2 BV. The regenerated liquid may contain inorganic salts, alkalis, low-proportion alcohol additives, surfactants, or other components that can promote PFAS desorption. In addition, to reduce the load and safety risks of the subsequent regenerated liquid treatment unit 104, a low-chlorine, low-organic additive or recyclable additive system may be used, and necessary gas-liquid separation, dilution, solvent recovery, or liquid conditioning steps may be provided before the NTP treatment in the regenerated liquid treatment unit 104.

[0065] In addition, the NTP regeneration step S4 also includes NTP treatment in the regenerated liquid treatment unit 104 and defluorination / conditioning treatment in the regenerated liquid conditioning unit 105. After the regenerated liquid restores its ability to desorb PFAS on the IX resin, it is reused for IX resin regeneration in the IX resin adsorption unit 101.

[0066] In the effect evaluation step S5, the regeneration effect of IX resin is evaluated to determine whether the regeneration effect of IX resin is qualified. In this embodiment, the regeneration effect can be evaluated based on resin capacity recovery rate, PFAS selective recovery rate, exchange capacity, resin structural integrity, residual PFAS in the regenerated solution, and F. - The regeneration efficiency was evaluated based on factors such as release rate, TOF / EOF ratio, exhaust gas fluoride capture rate, and multi-cycle stability. As an example, a regeneration efficiency of 80% or higher was considered sufficient for the regeneration of the IX resin. Here, regeneration efficiency refers to the ratio of the adsorption capacity of the regenerated IX resin to its initial adsorption capacity (the adsorption capacity of the unused IX resin).

[0067] In addition, if the regeneration effect of IX resin is deemed unqualified, the process returns to NTP regeneration step S4 to continue the circulation of the regenerated solution.

[0068] In the effect evaluation step S5, if the regeneration effect of the IX resin is deemed satisfactory, the system proceeds to the recovery operation step S6, where PFAS-containing water resumes flowing into the IX resin adsorption unit 101. This achieves the circulation of the entire water treatment system.

[0069] [Second Implementation]

[0070] The adsorption and regeneration system for IX resin according to the first embodiment and the method of using the system have been described above. However, the present invention is not limited to this embodiment. Next, refer to... Figure 3 The adsorption and regeneration system of IX resin according to the second embodiment of the present invention will be described. Figure 3 This is a structural diagram of the IX resin adsorption unit 201 in the IX resin adsorption and regeneration system of the second embodiment of the present invention.

[0071] In this embodiment, the regenerated liquid treatment unit is not independently disposed in the regenerated liquid circulation path, but is integrated into the IX resin adsorption unit 201. Other structures are the same as in the first embodiment described above, therefore related descriptions are omitted.

[0072] like Figure 3 As shown, the IX resin adsorption unit 201 includes a housing 214 and a high-voltage electrode 212. The housing 214 is connected to a ground electrode. An IX resin bed 213 is housed within the housing 214. The high-voltage electrode 212 is rod-shaped and inserted into the interior of the housing 214. By energizing the high-voltage electrode 212, a discharge can occur between the high-voltage electrode 212 and the housing 214, forming a dielectric barrier discharge region and generating NTP.

[0073] Furthermore, a liquid inlet and a liquid outlet are formed on the housing 214 of the IX resin adsorption unit 201, through which PFAS-containing water and regenerated liquid can be supplied to the IX resin adsorption unit 201. The supply of PFAS-containing water or regenerated liquid can be selected by operating a switching valve.

[0074] Furthermore, similar to the first embodiment, the regenerated liquid circulation path is connected to the liquid inlet and liquid outlet on the housing 214, thereby enabling the circulation of the regenerated liquid. A regenerated liquid tank 202 and a regenerated liquid regulating unit 205 can be provided on the regenerated liquid circulation path.

[0075] When water treatment is performed using the IX resin adsorption unit 201, water containing PFAS is introduced into the IX resin adsorption unit 201, thereby utilizing the IX resin to adsorb PFAS.

[0076] When the IX resin is saturated, the water containing PFAS is drained, and a small volume of regenerant is introduced. The regenerant causes the PFAS on the IX resin to desorb into the regenerant phase. The volume of regenerant introduced into the IX resin adsorption unit 201 is preferably 0.5 BV to 5 BV, more preferably 0.5 BV to 2 BV.

[0077] The IX resin body exhibits high resistivity and dielectric strength. By draining PFAS-containing water and controlling the water content, conductivity, electrode spacing, gas composition, power density, and processing time of the IX resin bed, liquid-phase short circuits, localized hot spots, and damage to resin functional groups during discharge can be avoided. Furthermore, due to the small volume of the introduced regenerated solution, short circuits caused by the regenerated solution that could affect discharge can be prevented.

[0078] Under semi-dry conditions in the IX resin bed 213, the migration of some adsorbed PFAS from the resin surface or pores to the liquid / gas phase can be promoted by gas purging, electric field disturbance, local mild thermal effect, and changes in resin surface properties.

[0079] Subsequently, a power source can be connected to the high-voltage electrode 212, and discharge can occur between the high-voltage electrode 212 and the grounded casing 214 to generate NTP. The high-energy electrons, UV / VUV, O3, H2O2, and other redox active species generated by NTP mainly act on the PFAS or migrating PFAS that have been desorbed into the regeneration solution, causing them to undergo chain scission, defluorination, and transformation. Thus, NTP treatment of PFAS-containing regeneration solution or migrating PFAS can be achieved in the IX resin adsorption unit 201.

[0080] The regenerated liquid, after NTP treatment in the IX resin adsorption unit 201, can be treated by the defluorination conditioning unit 205 in the regenerated liquid circulation path to restore its ability to desorb PFAS from the IX resin and be reused for the regeneration of the IX resin.

[0081] The IX resin adsorption and regeneration system and method of the present invention have been described above, and have the following significant advantages:

[0082] (1) Strong closed-loop performance: The present invention embeds the NTP treatment of PFAS-containing regenerated liquid into the regenerated liquid loop, instead of treating the regenerated liquid as a separate waste liquid.

[0083] (2) Continuous desorption driving force: By reducing the concentration of PFAS in the regenerated solution, the concentration gradient from the resin phase to the liquid phase can be maintained continuously, thereby enhancing the regeneration effect.

[0084] (3) Reduced waste liquid volume: The regenerated liquid is reused after defluorination / conditioning, which can significantly reduce the consumption of fresh regenerated liquid and the discharge of PFAS-containing regenerated waste liquid.

[0085] (4) Strong engineering adaptability: It is suitable for drinking water, groundwater, industrial wastewater, membrane concentrate combined use and multi-column continuous operation scenarios.

[0086] (5) Complete evaluation system: Simultaneous examination of PFAS removal, defluorination, TOF / EOF, resin capacity recovery and material stability is helpful to prove that it is not simply a transfer of pollutants.

Claims

1. An adsorption and regeneration system for IX resin, comprising: The IX resin adsorption unit is used to adsorb water containing perfluorinated and polyfluoroalkyl substances (PFAS). A regenerated liquid circulation path is used to circulate regenerated liquid to the IX resin adsorption unit, the regenerated liquid being used to desorb PFAS from the IX resin. The regenerated liquid circulation path includes: A regeneration tank, which stores regeneration liquid and receives regeneration liquid discharged from the IX resin adsorption unit; The regenerated liquid treatment unit performs NTP treatment on the PFAS-containing regenerated liquid. In the NTP treatment, low-temperature plasma, i.e., NTP, is generated by discharge to degrade the PFAS in the regenerated liquid. The regenerated liquid conditioning unit conditions the regenerated liquid after NTP treatment to restore its ability to desorb PFAS, and then feeds it into the IX resin adsorption unit.

2. The adsorption and regeneration system for IX resin according to claim 1, wherein, In the regenerated liquid circulation path, the regenerated liquid treatment unit is an NTP treatment unit located downstream of the regeneration tank. The NTP treatment unit receives regenerated liquid containing PFAS from the regenerated liquid tank and sends the NTP-treated regenerated liquid to the regenerated liquid conditioning unit.

3. The adsorption and regeneration system for IX resin according to claim 1, wherein, The regenerated liquid treatment unit is disposed within the IX resin adsorption unit. In the IX resin adsorption unit, after PFAS is desorbed by the regenerated liquid, NTP is generated by discharge to degrade the PFAS in the regenerated liquid.

4. The adsorption and regeneration system for IX resin according to claim 3, wherein, The outer shell of the IX resin adsorption unit is connected to the grounding electrode, and a high-voltage electrode is inserted inside the IX resin adsorption unit. NTP is generated by discharging through the high-voltage electrode.

5. The adsorption and regeneration system for IX resin according to any one of claims 1 to 4, wherein, The regenerated liquid conditioning unit includes a defluorination unit, which is used to remove or control F-, HF, and fluorine-containing intermediates.

6. The adsorption and regeneration system for IX resin according to claim 5, wherein, The defluorination unit removes fluoride through one or more of the following methods: precipitation of calcium, magnesium or aluminum salts, special defluorination adsorbents, anion exchange, membrane separation, and alkaline washing absorption.

7. The adsorption and regeneration system for IX resin according to claim 5, wherein, The regenerated liquid conditioning unit includes a conditioning unit that adjusts at least one of the following: pH, conductivity, ionic strength, redox state, regenerator concentration, and organic additive concentration of the regenerated liquid.

8. The adsorption and regeneration system for IX resin according to any one of claims 1 to 4, wherein, The adsorption and regeneration system of the IX resin includes multiple IX resin adsorption units. When regenerant is introduced into one IX resin adsorption unit, water containing PFAS is allowed to flow into other IX resin adsorption units.

9. A method for adsorption and regeneration of IX resin, using the adsorption and regeneration system of IX resin according to any one of claims 1 to 7, comprising the following steps: In the adsorption step, water containing perfluorinated and polyfluoroalkyl substances, i.e., PFAS, is passed through the IX resin adsorption unit, and the PFAS are adsorbed by the IX resin. The saturation detection step involves detecting the operating status of the IX resin adsorption unit to determine whether the IX resin is saturated. Switch the operating steps, stop the inflow of PFAS-containing water into the IX resin adsorption unit, and introduce regeneration solution; The NTP regeneration step utilizes the regenerated solution to desorb PFAS from the IX resin. The effect evaluation step assesses the regeneration effect of the IX resin and determines whether the regeneration effect of the IX resin is qualified. The operation is restored by resuming the flow of PFAS-containing water into the IX resin adsorption unit after determining that the regeneration effect of the IX resin is qualified.

10. The method for adsorption and regeneration of IX resin according to claim 9, wherein, In the NTP regeneration step, PFAS in the regenerated liquid are degraded by the regenerated liquid treatment unit, and the regenerated liquid's ability to desorb PFAS is restored by the regenerated liquid conditioning unit.

11. The method for adsorption and regeneration of IX resin according to claim 9, wherein, The volume of regenerated liquid introduced into the IX resin is 0.5 BV to 5 BV.

12. The method for adsorption and regeneration of IX resin according to claim 11, wherein, The volume of regenerated liquid introduced into the IX resin is 0.5 BV to 2 BV.

13. The method for adsorption and regeneration of IX resin according to claim 8, wherein, In the effect evaluation step, when the regeneration efficiency is above 80%, the regeneration effect of IX resin is judged to be qualified. The regeneration efficiency is the ratio of the adsorption capacity of the regenerated IX resin to the initial adsorption capacity of the IX resin.

Images