Ion exchange resin regeneration wastewater quality-divided treatment and recycling system

Abstract

The utility model discloses a quality-divided treatment and recycling system for ion exchange resin regenerated wastewater. The quality-divided treatment and recycling system comprises a raw water pretreatment system, an ion exchanger and regeneration system, a nanofiltration device and an electrolytic wastewater chlorine production system which are communicated in sequence, an on-line chloride ion meter, an on-line sodium ion meter, matched pipelines and an electric actuator are additionally arranged on a wastewater outlet pipeline, different types of wastewater are collected according to high-chloride-ion-concentration wastewater, high-sodium-ion-concentration wastewater and low-concentration wastewater, and the low-concentration wastewater is recycled to a pre-raw water pool; the ion proportion of high-chloride-ion-concentration wastewater and high-sodium-ion-concentration wastewater is optimized through the mixing ratio, the purity of a regenerated solution is improved through a nanofiltration device, and the electrolytic chlorine production efficiency is improved. According to the utility model, the acid-base regeneration wastewater which is difficult to treat is collected according to quality and is recycled according to classes, so that the resource utilization of the wastewater is realized.

Description

Technical Field

[0001] This utility model relates to the field of industrial wastewater treatment technology, and in particular to a highly efficient system for the fractional treatment and resource utilization of acid-base regeneration wastewater from ion exchange systems. Background Technology

[0002] During commissioning and regeneration, ion exchange systems in thermal power plants often discharge large amounts of wastewater, mainly including anion exchange, cation exchange, and mixed bed flushing wastewater, regeneration backwash drainage, acid-alkali regeneration wastewater, and forward wash drainage. Among these, the acid-alkali regeneration wastewater contains high concentrations of organic matter and large amounts of acid and alkali components. Thermal power plants often use neutralization to treat this wastewater, and the treated wastewater is then used for process water makeup in the desulfurization system and for flushing coal conveyor trestles. These reuse methods negatively impact the reuse system and are detrimental to its long-term operation.

[0003] Currently, using conductivity meters to separate acid and alkali regeneration wastewater is a common method in industrial water treatment. Its core principle is to determine the type or concentration difference of wastewater by monitoring its conductivity (reflecting the total ion concentration in the solution), thereby enabling the separate collection or treatment of wastewater based on its composition. However, since conductivity only characterizes the overall conductivity of a solution and cannot distinguish specific ion types, its application has certain limitations. Utility Model Content

[0004] To address the negative impact of neutralization treatment on reuse systems in existing technologies for acid and alkali wastewater, this invention provides a system for the selective treatment and resource recovery of ion exchange resin regeneration wastewater. Through ion selective detection, three treatment pipelines with varying ion concentrations are installed. These pipelines are equipped with electric actuators, wastewater tanks, wastewater reuse pumps, and collection devices corresponding to the specified ion concentrations. This system enables precise separation of different types of wastewater from ion exchange resin regeneration wastewater, allowing for its reuse and significantly extending the lifespan of the electrolytic membrane.

[0005] The technical solution of this utility model is as follows:

[0006] This utility model discloses a wastewater treatment and resource recovery system for ion exchange resin regeneration, comprising a raw water pretreatment system, an ion exchanger and regeneration system, a nanofiltration device, and an electrolytic wastewater chlorination system connected in sequence. The ion exchanger and regeneration system includes an online chloride ion meter, an online sodium ion meter, and a high-sodium ion wastewater tank, a high-chloride ion wastewater tank, and a low-concentration wastewater tank arranged in parallel. The online chloride ion meter and the online sodium ion meter are installed on the main line at the outlet of the mixed ion exchanger in the ion exchanger and regeneration system. Electric actuators for high-concentration sodium ion wastewater, high-concentration chloride ion wastewater, and low-concentration wastewater are respectively installed on the branch lines at the inlet of the high-sodium ion wastewater tank, the high-chloride ion wastewater tank, and the low-concentration wastewater tank. The outlets of the high-sodium ion wastewater tank and the high-chloride ion wastewater tank are respectively connected to the nanofiltration device. The outlet of the nanofiltration device is connected to the electrolytic wastewater chlorination system.

[0007] Furthermore, the ion exchanger and regeneration system also includes an acid inlet pipeline and an alkali inlet pipeline, with an electric actuator installed on the acid inlet pipeline and an electric actuator installed on the alkali inlet pipeline.

[0008] Furthermore, the raw water pretreatment system includes a pre-raw water tank, a pre-treatment sedimentation tank, and a pre-desalination device connected in sequence; the outlet of the pre-desalination device is connected to the ion exchanger and the mixed ion exchanger in the regeneration system through an inlet pipe, and the outlet of the mixed ion exchanger is connected to the demineralized water tank through an outlet pipe.

[0009] Furthermore, the low-concentration wastewater tank is connected to the pre-raw water tank via a low-concentration wastewater reuse pump.

[0010] Furthermore, a high-sodium ion wastewater reuse pump is installed on the branch line connecting the high-sodium ion wastewater tank and the nanofiltration device; a high-chlorine concentration wastewater reuse pump is installed on the branch line connecting the high-chlorine ion wastewater tank and the nanofiltration device.

[0011] Furthermore, the nanofiltration unit is also connected to the desulfurization system.

[0012] This utility model has the following beneficial effects:

[0013] 1. This utility model provides a system for the differentiated treatment and resource recovery of ion exchange resin regeneration wastewater. It solves the problems of resource waste, severe membrane fouling caused by divalent ions, electrode passivation, and low electrolysis efficiency in traditional ion exchange resin regeneration wastewater treatment by sequentially employing a technical path of precise ion separation and collection, mixing optimization, nanofiltration removal of interfering ions, and electrolysis resource recovery. Traditional conductivity meters cannot distinguish Cl... - and Na + This invention uses ion-selective detection to accurately identify target wastewater, providing a raw material basis for subsequent resource utilization.

[0014] 2. This utility model adds online chloride ion meters, online sodium ion meters, and their matching pipelines and electric actuators to the wastewater outlet pipe of the mixed ion exchanger, so as to collect different types of wastewater separately, improve the recycling rate, realize the resource utilization of wastewater, avoid the system operation deterioration caused by direct mixing of high-salt wastewater, reduce the pressure of downstream wastewater treatment, and solve the problem of no reuse and no treatment method for high-concentration wastewater from gas turbine units.

[0015] 3. This utility model, while simultaneously producing chlorine through electrolytic wastewater reuse, also incorporates wastewater reuse pumps and wastewater tanks with different concentrations and types of ions after precise ion separation and collection, thereby achieving the treatment of Cl in the wastewater. - / Na + By optimizing the mixing ratio and adjusting the ion ratio, and by setting up a nanofiltration device, "monovalent ions can pass through while divalent ions are retained," the problem of divalent ion interference in the subsequent electrolysis process is solved. When the final product enters the chlorination system from the electrolytic wastewater, the electrolysis efficiency can be increased to 85%, significantly extending the life of the electrolytic membrane, and the chlorine production per ton of water is ≥3.5 kg. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the ion exchanger and regeneration system in this utility model;

[0017] Figure 2 This is a schematic diagram of the overall structure of this utility model.

[0018] The reference numerals in the figure are as follows:

[0019] 1-Pre-raw water tank, 2-Pre-treatment sedimentation tank, 3-Pre-desalination device, 4-Ion exchanger and regeneration system, 5-Desalinated water tank, 6-Nanofiltration device, 7-Electrolytic wastewater chlorination system, 8-Desulfurization system, 41-Inlet water pipeline, 42-Acid inlet pipeline electric actuator, 43-Acid inlet pipeline, 44-Alkali inlet pipeline electric actuator, 45-Alkali inlet pipeline, 46-Online chloride ion meter, 47-Online sodium ion meter, 48-High concentration 49 - Electric actuator for high-concentration chloride ion wastewater pipeline; 410 - Electric actuator for low-concentration sodium ion wastewater pipeline; 411 - Low-concentration wastewater tank; 412 - High-sodium ion wastewater tank; 413 - High-chloride ion wastewater tank; 414 - High-chloride concentration wastewater reuse pump; 415 - High-sodium ion wastewater reuse pump; 416 - Low-concentration wastewater reuse pump; 417 - Effluent pipeline; 418 - Mixed ion exchanger. Detailed Implementation

[0020] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0021] See Figure 1 and 2A wastewater treatment and resource recovery system for ion exchange resin regeneration includes a raw water pretreatment system, an ion exchanger and regeneration system 4, a nanofiltration device 6, and an electrolytic wastewater chlorination system 7 connected in sequence. The raw water pretreatment system can perform pretreatment such as sedimentation, filtration, and desalination on the incoming raw water. The ion exchanger and regeneration system 4 includes an online chloride ion meter 46, an online sodium ion meter 47, and a high sodium ion wastewater tank 412, a high chloride ion wastewater tank 413, and a low concentration wastewater tank 411 arranged in parallel. The online chloride ion meter 46 and the online sodium ion meter 47 are installed on the main line at the outlet of the mixed ion exchanger 418 in the ion exchanger and regeneration system 4. The branch lines at the inlet of the high sodium ion wastewater tank 412, the high chloride ion wastewater tank 413, and the low concentration wastewater tank 411 are respectively equipped with a high concentration sodium ion wastewater pipeline electric actuator 49, a high concentration chloride ion wastewater pipeline electric actuator 48, and a low concentration wastewater electric actuator 410.

[0022] During normal operation, only the inlet pipe 41 and the outlet pipe 417 of the mixed ion exchanger 418 are operational. During regeneration, the inlet pipe 41 and the outlet pipe 417 are closed, and acid and alkali are introduced into the mixed ion exchanger 418 by opening the electric actuators 42 and 44 of the acid inlet pipe and 44 of the alkali inlet pipe, respectively. The regeneration wastewater is discharged from the mixed ion exchanger 418. An online chloride ion meter 46 and an online sodium ion meter 47 are installed on the wastewater discharge pipe. The online chloride ion meter 46 monitors the chloride ion concentration during regeneration. In this embodiment, the recommended measurement range for the online chloride ion meter 46 is 20 mg / L to 800 mg / L; a measurement range that is too large will cause errors. The online sodium ion meter 47 monitors the sodium ion concentration during regeneration, and the recommended measurement range is 20 mg / L to 800 mg / L. Excessive measurement range will cause errors; when the chloride ion concentration in the regeneration solution exceeds 50 mg / L, the electric actuator 48 of the high-concentration chloride ion wastewater pipeline opens the valve, and the high-concentration chloride ion wastewater enters the high-concentration chloride ion wastewater tank 413; when the sodium ion concentration in the regeneration solution exceeds 50 mg / L, the electric actuator 49 of the high-concentration sodium ion wastewater pipeline opens the valve, and the high-concentration sodium ion wastewater enters the high-concentration sodium ion wastewater tank 412; when, during the regeneration process, the online chloride ion meter 46 and the online sodium ion meter 47 fail to detect chloride and sodium ion concentrations higher than 50 mg / L, the low-concentration wastewater electric actuator 410 opens, and the wastewater at this time enters the low-concentration wastewater tank 411; through the above separate monitoring and control, the separate collection of high-concentration chloride ion wastewater, high-concentration sodium ion wastewater, and low-concentration wastewater is achieved;

[0023] The effluent outlets of the high sodium ion wastewater tank 412 and the high chloride ion wastewater tank 413 are respectively connected to the nanofiltration device 6; the effluent outlet of the nanofiltration device 6 is connected to the electrolytic wastewater chlorination system 7; the low concentration wastewater tank 411 is connected to the pre-raw water tank 1 through the low concentration wastewater reuse pump 416; a high sodium ion wastewater reuse pump 415 is installed on the branch connecting the high sodium ion wastewater tank 412 and the nanofiltration device 6; a high chloride concentration wastewater reuse pump 414 is installed on the branch connecting the high chloride ion wastewater tank 413 and the nanofiltration device 6.

[0024] After wastewater is collected separately, low-concentration wastewater is recycled to the pre-raw water tank 1 via low-concentration wastewater reuse pump 416 for system utilization; high-chloride and high-sodium ion wastewater are mixed at a volume ratio of 1:(0.8-1.2) via high-chloride wastewater reuse pump 414 and high-sodium ion wastewater reuse pump 415 to form Cl... - with Na + A mixture with a molar ratio close to 1:1 enters nanofiltration device 6. In this embodiment, nanofiltration device 6 uses a spiral-wound polyamide composite membrane with a molecular weight cutoff of 200-300 Da, operating at a pressure of 0.8-1.5 MPa, capable of removing ≥90% of Ca from the mixture. 2+ Mg 2+ The permeate from nanofiltration unit 6 enters the electrolytic wastewater chlorination system 7 to achieve high-concentration NaCl solution electrolysis. The electrolytic wastewater chlorination system 7 pumps the nanofiltration permeate (divalent ions ≤ 50 mg / L) into the electrolytic cell, where sodium hypochlorite solution or chlorine gas is generated through diaphragm electrolysis. In this embodiment, the electrolytic cell of the electrolytic wastewater chlorination system 7 is a diaphragm electrolytic cell coated with ruthenium-iridium electrodes. Through precise pre-separation and nanofiltration optimization of the regeneration solution in this embodiment, the electrolysis efficiency is increased to over 85%.

[0025] In a preferred embodiment, the concentrate from the nanofiltration unit 6 is also reused in the desulfurization system 8 as makeup water for the system's process water, since the concentrate is mostly composed of calcium. 2+ Mg 2+ It will not increase the chloride ion concentration in the desulfurization slurry and has virtually no impact on the desulfurization system.

[0026] In a preferred embodiment, the ion exchanger and regeneration system 4 further includes an acid inlet pipe 43 and an alkali inlet pipe 45. An acid inlet pipe 43 is equipped with an acid inlet pipe electric actuator 42, and an alkali inlet pipe 45 is equipped with an alkali inlet pipe electric actuator 44. When the mixed ion exchanger 418 fails, it needs to be regenerated with acid and alkali. At this time, the acid and alkali are introduced by opening the acid inlet pipe electric actuator 42 or the alkali inlet pipe electric actuator 44, thereby realizing the regeneration of the mixed ion exchanger 418.

[0027] In a preferred embodiment, the raw water pretreatment system includes a pre-raw water tank 1, a pretreatment sedimentation tank 2, and a pre-desalination device 3 connected in sequence. The outlet of the pre-desalination device 3 is connected to the mixed ion exchanger 418 in the ion exchanger and regeneration system 4 via an inlet pipe 41. The outlet of the mixed ion exchanger 418 is connected to the demineralized water tank 5 via an outlet pipe 417. The product water of the pre-desalination device 3 is used as the inlet water of the ion exchanger and regeneration system 4 during normal operation. The product water of the ion exchanger and regeneration system 4 during normal operation enters the demineralized water tank 5. At the same time, the water in the demineralized water tank 5 is used as the water for the regeneration of the ion exchanger and regeneration system 4.

[0028] The above description is merely an embodiment of the utility model and does not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made using the content of this utility model specification, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A system for the treatment and resource utilization of ion exchange resin regeneration wastewater, characterized in that: The system comprises a raw water pretreatment system, an ion exchanger and regeneration system (4), a nanofiltration device (6) and an electrolytic wastewater chlorine production system (7) connected in sequence; the ion exchanger and regeneration system (4) comprises an online chloride ion meter (46), an online sodium ion meter (47), and a high-sodium ion wastewater tank (412), a high-chloride ion wastewater tank (413) and a low-concentration wastewater tank (411) arranged in parallel; the online chloride ion meter (46) and the online sodium ion meter (47) are arranged on the main line at the outlet of the mixed ion exchanger (418) in the ion exchanger and regeneration system (4); the high-sodium ion wastewater tank (412), the high-chloride ion wastewater tank (413) and the low-concentration wastewater tank (411) are arranged with a high-concentration sodium ion wastewater pipeline electric actuator (49), a high-concentration chloride ion wastewater pipeline electric actuator (48) and a low-concentration wastewater pipeline electric actuator (410) respectively at the inlet branch; the outlets of the high-sodium ion wastewater tank (412) and the high-chloride ion wastewater tank (413) are connected to the nanofiltration device (6); the outlet of the nanofiltration device (6) is connected to the electrolytic wastewater chlorine production system (7).

2. The ion exchange resin regeneration wastewater multi-quality treatment and resource system according to claim 1, characterized in that: The ion exchanger and regeneration system (4) further comprises an acid inlet pipeline (43) and an alkali inlet pipeline (45), and the acid inlet pipeline (43) is provided with an acid inlet pipeline electric actuator (42), and the alkali inlet pipeline (45) is provided with an alkali inlet pipeline electric actuator (44).

3. The ion exchange resin regeneration wastewater multi-quality treatment and resource system according to claim 1, characterized in that: The raw water pretreatment system comprises a pre-raw water tank (1), a pretreatment sedimentation tank (2) and a pre-desalination device (3) connected in sequence; the outlet of the pre-desalination device (3) is connected to the ion exchanger and regeneration system (4) through a water inlet pipeline (41), and the outlet of the ion exchanger and regeneration system (4) is connected to a desalted water tank (5) through a water outlet pipeline (417).

4. The ion exchange resin regeneration wastewater multi-quality treatment and resource system according to claim 1, characterized in that: The low-concentration wastewater tank (411) is connected to the pre-raw water tank (1) through a low-concentration wastewater recycling pump (416).

5. The ion exchange resin regeneration wastewater multi-quality treatment and resource system according to claim 1, characterized in that: A high-sodium ion wastewater recycling pump (415) is arranged on the branch connecting the high-sodium ion wastewater tank (412) and the nanofiltration device (6); a high-chloride ion wastewater recycling pump (414) is arranged on the branch connecting the high-chloride ion wastewater tank (413) and the nanofiltration device (6).

6. The ion exchange resin regeneration wastewater multi-quality treatment and resource system according to claim 1, characterized in that: The nanofiltration device (6) is further connected to a desulfurization system (8).

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