TMAH waste liquid online recovery zero discharge system

Abstract

The invention provides a TMAH waste liquid online recovery zero discharge system, which relates to the technical field of waste water treatment and material separation and recovery, and comprises a high-concentration waste liquid treatment subsystem and a low-concentration waste liquid treatment subsystem which are connected with each other, the high-concentration waste liquid treatment subsystem is sequentially provided with a first filtering device, a first nanofiltration device and a first purification device; the low-concentration waste liquid treatment subsystem is sequentially provided with a first air flotation precipitation device, a second filtering device, a second nanofiltration device, a reverse osmosis device and a second purification device; the first purification device is connected with the air flotation precipitation device; the first nanofiltration device, the first purification device and the second purification device are all connected with a recycling tank; the high-concentration and low-concentration TMAH waste liquid is respectively sent to a high-concentration waste liquid treatment subsystem and a low-concentration waste liquid treatment subsystem, and finally a purified TMAH product is obtained and is subjected to on-line recycling after the TMAH product meets the use concentration of TMAH through proportioning and mixing. According to the method, simultaneous online recycling and zero emission of the high-concentration and low-concentration TMAH waste liquid are realized.

Description

Technical Field

[0001] The present invention relates to the technical field of wastewater treatment and material separation and recovery, and in particular to an on-line recovery zero-emission system for TMAH waste liquid. Background Art

[0002] The array process (Array) in liquid crystal panel manufacturing includes processes such as cleaning, film formation, photoresist coating, exposure, development, etching, and photoresist stripping. The photoresist used in the process consists of components such as resin, photosensitive material, solvent, and additive. After exposure, its properties change and it is dissolved and removed by an alkaline developer in the development process. The TMAH (tetramethylammonium hydroxide) solution dissolved with the photoresist discharged in the development process is the developer waste liquid or is called TMAH waste liquid.

[0003] The characteristics of TMAH waste liquid are high pollutant concentration, and the TMAH concentration can reach hundreds to tens of thousands of ppm; the OH group in the TMAH structure gives it strong alkalinity and corrosiveness; the TMA group is a kind of neurotoxin similar to that of poisonous snails, which has inhibitory effect on wastewater treatment microorganisms at high concentrations and is difficult to be decomposed by microorganisms; the developer waste liquid contains dissolved photoresist, mainly including metal ion impurities such as resin, aluminum, iron, copper, and additives; quite a part of TMAH wastewater contains hydrogen peroxide, and hydrogen peroxide has strong oxidizing property. - group makes it have strong alkalinity and corrosiveness; TMA + group is a kind of neurotoxin similar to that of poisonous snails, which has inhibitory effect on wastewater treatment microorganisms at high concentrations and is difficult to be decomposed by microorganisms; the developer waste liquid contains dissolved photoresist, mainly including metal ion impurities such as resin, aluminum, iron, copper, and additives; quite a part of TMAH wastewater contains hydrogen peroxide, and hydrogen peroxide has strong oxidizing property.

[0004] At present, the common treatment method in semiconductor and panel manufacturing plants is to discharge high and low concentration TMAH waste liquids into the organic wastewater treatment system of the factory wastewater station. First, the waste liquid is diluted by organic wastewater, and then biological denitrification processes such as AO or A2O are used to degrade and remove TMAH.

[0005] Problems existing in the prior art include: the wastewater biochemical system has a low tolerance to TMAH concentration and requires strict operation and management; the treatment load of the wastewater biochemical system is low, and the overall construction cost and energy consumption are high; TMAH is wasted and cannot be recycled for use.

[0006] Therefore, how to achieve efficient treatment of TMAH waste liquid while recovering TMAH and realizing efficient, economic and zero-emission of TMAH waste liquid. Summary of the Invention

[0007] In view of the above problems, the present invention provides an on-line recovery zero-emission system for TMAH waste liquid.

[0008] To achieve the above object, the present invention provides an on-line recovery zero-emission system for TMAH waste liquid, including a high-concentration waste liquid treatment subsystem and a low-concentration waste liquid treatment subsystem connected to each other; The high-concentration waste liquid treatment subsystem includes a first filtration device, a first nanofiltration device, and a first purification device connected in sequence; The low-concentration waste liquid treatment subsystem includes a first air flotation sedimentation device, a second filtration device, a second nanofiltration device, a reverse osmosis device, and a second purification device connected in sequence; The first purification device is connected to the air flotation sedimentation device; The first nanofiltration device, the first purification device, and the second purification device are all connected to a reuse tank; The high-concentration TMAH waste liquid is sent to the high-concentration waste liquid treatment subsystem. Suspended solids and colloids are removed by the first filtration device. Nanofiltration fresh water and nanofiltration concentrated water containing photoresist and divalent ions are separated by the first nanofiltration device. The nanofiltration concentrated water is purified by the first purification device to obtain purified TMAH products and low-concentration TMAH waste liquid. The nanofiltration fresh water and TMAH products are sent to the reuse tank, and the low-concentration TMAH waste liquid is sent to the low-concentration waste liquid treatment subsystem; the supernatant is separated from the low-concentration TMAH waste liquid by the first air flotation sedimentation device. Suspended solids and colloids are removed from the supernatant by the second filtration device. Nanofiltration fresh water and nanofiltration concentrated water containing photoresist and divalent ions are separated by the second nanofiltration device. The nanofiltration fresh water is desalted and concentrated by the reverse osmosis device to obtain reverse osmosis concentrated water. Purified TMAH products are obtained by the second purification device and sent to the reuse tank. High-purity water is added to the reuse tank to make the ratio in the reuse tank meet the use concentration of TMAH for online reuse.

[0009] As a further improvement of the present invention, it further includes a waste liquid collection tank, which is arranged at the front end of the first filtration device and is connected to the high-concentration TMAH waste liquid through a pipeline.

[0010] As a further improvement of the present invention, it further includes a concentrated water tank and a fresh water tank. The concentrated water tank is arranged between the first nanofiltration device and the first purification device, and the fresh water tank is arranged between the second purification device and the first air flotation sedimentation device; The nanofiltration concentrated water separated by the first nanofiltration device is temporarily stored in the concentrated water tank; The low-concentration TMAH waste liquid obtained from the high-concentration waste liquid treatment subsystem is temporarily stored in the fresh water tank; The fresh water tank is connected to external low-concentration TMAH waste liquid through a pipeline.

[0011] As a further improvement of the present invention, the second nanofiltration device is further connected to a second air flotation sedimentation device, and the second air flotation sedimentation device is connected to the fresh water tank; The nanofiltration concentrated water containing photoresist and divalent ions separated by the second nanofiltration device is separated into supernatant and sediment by the second air flotation sedimentation device, and the supernatant flows back to the fresh water tank for further treatment.

[0012] As a further improvement of the present invention, the reverse osmosis device is also connected to a desalted water tank; The nanofiltration fresh water separated by the second nanofiltration device is desalinated and concentrated by the reverse osmosis device to obtain reverse osmosis fresh water, and the reverse osmosis fresh water is sent to the desalted water tank for storage.

[0013] As a further improvement of the present invention, the second purification device is also connected to the first flotation sedimentation device and the second flotation sedimentation device to send the purified by-products to the first flotation sedimentation device and the second flotation sedimentation device for secondary utilization.

[0014] As a further improvement of the present invention, the first filtering device and the second filtering device are both provided with two-stage or multi-stage filters, and the filters include filter element filters, filter bag filters, sand filters, microfiltration membrane filtration, and ultrafiltration membrane filtration.

[0015] As a further improvement of the present invention, both the first nanofiltration device and the second nanofiltration device are provided with one or more stages of monovalent and divalent separation nanofiltration membranes.

[0016] As a further improvement of the present invention, the first purification device and the second purification device both include a power supply, electrodes, anion and cation exchange membranes and partitions, and separate and purify the TMAH product through the directional migration of conductive ions.

[0017] As a further improvement of the present invention, the first flotation precipitation device and the second flotation precipitation device are both provided with a reaction zone, a precipitation zone, a flotation zone and a dosing device, and the pH is adjusted by the dosing device to separate the photoresist and divalent ions in the TMAH waste liquid.

[0018] Compared with the prior art, the present invention has the following beneficial effects: The present invention solves the problem that high-concentration and low-concentration TMAH waste liquids cannot be recycled online at the same time by sequentially connecting a high-concentration waste liquid treatment subsystem and a low-concentration waste liquid treatment subsystem. At the same time, the TMAH waste liquid is purified into a TMAH product and desalted water, and the TMAH waste liquid is reused online in production, thereby realizing efficient recycling and zero emission of the TMAH waste liquid.

[0019] The system of the present invention does not introduce any reagents that pollute the product during the treatment process, and removes pollutants in TMAH waste liquid through the organic coupling of multiple physical and chemical methods, thereby ensuring the online purity of the TMAH product and enabling better online recycling of the TMAH product.

[0020] The present invention achieves zero discharge of TMAH waste liquid by coupling multiple physical and chemical treatment devices and utilizing internal product recycling. Compared with the investment cost and treatment cost of existing treatment technologies, the present invention has significant improvement and achieves energy saving, consumption reduction and resource utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic diagram of an online recovery zero - discharge system for TMAH waste liquid disclosed in an embodiment of the present invention. Specific embodiments

[0022] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0023] The present invention will be further described in detail below with reference to the accompanying drawings: As Figure 1 shown, an online recovery zero - discharge system for TMAH waste liquid provided by the present invention includes: a high - concentration waste - liquid treatment subsystem and a low - concentration waste - liquid treatment subsystem connected to each other; The high - concentration waste - liquid treatment subsystem includes a first filtration device, a first nanofiltration device and a first purification device connected in sequence; The low - concentration waste - liquid treatment subsystem includes a first air - flotation sedimentation device, a second filtration device, a second nanofiltration device, a reverse osmosis device and a second purification device connected in sequence; The first purification device is connected to the air - flotation sedimentation device; The first nanofiltration device, the first purification device and the second purification device are all connected to the reuse tank; The high-concentration TMAH waste liquid generated in the developing section is sent to the high-concentration waste liquid treatment subsystem. The first filtration device consists of two-stage filter bag filters and ultrafiltration membranes. The high-concentration TMAH waste liquid removes impurities such as suspended solids and colloids through the first filtration device. The first nanofiltration device separates nanofiltration fresh water and nanofiltration concentrated water containing photoresist, divalent ions, etc. The nanofiltration recovery rate is 90%. The nanofiltration concentrated water obtains purified TMAH products and low-concentration TMAH waste liquid through the first purification device. The first purification device is an electrochemical component composed of anion and cation exchange membranes, a power supply, electrodes, separators, etc. The purified TMAH products are separated through the directional migration of conductive ions. 90% of the nanofiltration fresh water and TMAH products are sent to the reuse tank. The low-concentration TMAH waste liquid contains pollutants such as photoresist and divalent ions and is sent to the low-concentration waste liquid treatment subsystem. The low-concentration TMAH waste liquid generated in the developing section and the low-concentration TMAH waste liquid obtained from the high-concentration waste liquid treatment subsystem are sent to the first air flotation and sedimentation device. The low-concentration TMAH waste liquid separates the supernatant through the first air flotation and sedimentation device. The supernatant removes impurities such as suspended solids and colloids through the second filtration device. The second nanofiltration device separates nanofiltration fresh water and nanofiltration concentrated water containing photoresist, divalent ions, etc. The nanofiltration recovery rate is 90%. 90% of the nanofiltration fresh water is desalted and concentrated through the reverse osmosis device to obtain reverse osmosis concentrated water. The reverse osmosis recovery rate is 80%. 20% of the reverse osmosis concentrated water is separated and purified through the second purification device. The second purification device is an electrochemical component composed of anion and cation exchange membranes, bipolar membranes, a power supply, electrodes, separators, etc. The purified TMAH products and acid are separated through the directional migration of conductive ions. The purified TMAH products are sent to the reuse tank. High-purity water is added to the reuse tank to make the ratio in the reuse tank meet the use concentration of TMAH for online reuse.

[0024] Specifically: The present invention further includes a waste liquid collection tank, which is arranged at the front end of the first filtration device. The high-concentration TMAH waste liquid generated in the developing section is collected in the waste liquid collection tank through a pipeline.

[0025] An intermediate water tank is arranged between the first filtration device and the first nanofiltration device of the present invention. The filtered high-concentration TMAH waste liquid first flows into the intermediate water tank for temporary storage and is then pumped to the first nanofiltration device.

[0026] The present invention further includes a concentrated water tank, which is arranged between the first nanofiltration device and the first purification device. The nanofiltration concentrated water separated by the first nanofiltration device is temporarily stored in the concentrated water tank; The present invention further includes a fresh water tank, which is arranged between the second purification device and the first air flotation sedimentation device; the low-concentration TMAH waste liquid obtained by the high-concentration waste liquid treatment subsystem is temporarily stored in the fresh water tank; the fresh water tank is also connected to external low-concentration TMAH waste liquid through a pipeline, such as the low-concentration TMAH waste liquid generated in the developing section; further, the second nanofiltration device is also connected to a second air flotation sedimentation device, and the second air flotation sedimentation device is connected to the fresh water tank; the nanofiltration concentrated water containing photoresist and divalent ions separated by the second nanofiltration device is separated into supernatant and sediment by the second air flotation sedimentation device, and the supernatant flows back to the fresh water tank for further treatment.

[0027] A stirrer is arranged in the fresh water tank to mix the waste liquid. The low-concentration TMAH waste liquid homogenized by the stirrer is pumped to the first air flotation sedimentation device through a pump. The first air flotation sedimentation device is provided with a reaction zone, a sedimentation zone, an air flotation zone and a dosing device. In the first air flotation sedimentation device, the low-concentration TMAH waste liquid enters the reaction zone, and the acid generated by the second purification device is added to the reaction zone to adjust the pH to neutral or acidic. The adjusted low-concentration TMAH waste liquid flows into the sedimentation zone and the air flotation zone to realize the sedimentation and air flotation separation of sediments such as photoresist and suspended matter. In the present invention, the reverse osmosis device is also connected to a desalted water tank; 90% of the nanofiltration fresh water separated by the second nanofiltration device is desalted and concentrated by the reverse osmosis device to obtain reverse osmosis fresh water, and the reverse osmosis fresh water is sent to the desalted water tank for storage for reuse.

[0028] The second purification device of the present invention is also connected to the first air flotation sedimentation device and the second air flotation sedimentation device. The acid and TMAH products purified by the second purification device are respectively sent to the first air flotation sedimentation device and the second air flotation sedimentation device. The acid added to the first air flotation sedimentation device adjusts the pH of the reaction zone to neutral or acidic and flows into the sedimentation zone and the air flotation zone to realize the sedimentation and air flotation separation of sediments such as photoresist and suspended matter; the TMAH product added to the second air flotation sedimentation device adjusts the pH of the reaction zone to alkaline and flows into the sedimentation zone and the air flotation zone to realize the sedimentation and air flotation separation of sediments such as divalent ions, and finally realizes the recycling of TMAH waste liquid.

[0029] In the present invention, the sediments obtained by the first air flotation sedimentation device and the second air flotation sedimentation device can be dehydrated through equipment such as pressure filtration and drying, or can be directly sent to the sludge treatment system of the in-plant sewage treatment station for joint treatment.

[0030] In the present invention, the TMAH waste liquid on-line recovery zero-emission system is also provided with a supporting tail gas collection system for collecting and treating tail gas.

[0031] In the present invention, the first filtration device and the second filtration device are both provided with two-stage or multi-stage filters, and the filters include cartridge filters, filter bag filters, sand filters, microfiltration membrane filtration, ultrafiltration membrane filtration, etc.

[0032] In the present invention, both the first nanofiltration device and the second nanofiltration device are provided with one or more stages of nanofiltration membranes for separating monovalent and divalent ions, and the recovery rate is set above 80%.

[0033] In the present invention, both the first purification device and the second purification device include a power supply, electrodes, anion and cation exchange membranes, and partitions, and separate and purify the TMAH product through the directional migration of conductive ions.

[0034] In the present invention, both the first air flotation and precipitation device and the second air flotation and precipitation device are provided with a reaction zone, a precipitation zone, an air flotation zone, and a chemical dosing device. The pH is adjusted through the chemical dosing device to separate the photoresist and divalent ions in the TMAH waste liquid.

[0035] In the present invention, the reverse osmosis device is provided with one or more stages of desalination reverse osmosis membranes, and the recovery rate is set above 80%. Example:

[0036] Apply the on-line recovery and zero-emission system for TMAH waste liquid of the present invention to simultaneously recover the high-concentration and low-concentration TMAH waste liquid generated in the developing section. Connect the high-concentration TMAH waste liquid generated in the developing section to the waste liquid collection tank through a pipeline, and connect the low-concentration TMAH waste liquid generated in the developing section to the fresh water tank through a pipeline. The specific treatment process includes: Step 1: Pump the high-concentration TMAH waste liquid in the waste liquid collection tank to the first filtration device composed of two-stage filter bag filters and ultrafiltration membranes, and remove substances such as suspended solids and colloids through filtration treatment; Step 2: The filtered high-concentration TMAH waste liquid flows into the first intermediate water tank for temporary storage, and then is pumped from the intermediate water tank to the first nanofiltration device. The high-concentration TMAH waste liquid is separated to obtain nanofiltration concentrated water containing photoresist, divalent ions, etc. and nanofiltration fresh water. The nanofiltration concentrated water enters the concentrated water tank, the nanofiltration recovery rate is 90%, and 90% of the nanofiltration fresh water enters the reuse tank; Step 3: Pump the high-concentration TMAH waste liquid in the concentrated water tank to the first purification device, and separate and purify the high-concentration TMAH waste liquid through the first purification device. The first purification device is composed of anion and cation exchange membranes, a power supply, electrodes, partitions, etc., and separates and purifies the TMAH product through the directional migration of conductive ions. The purified TMAH product is sent to the reuse tank, and the remaining TMAH waste liquid after separation contains pollutants such as photoresist and divalent ions, and is sent to the fresh water tank; Step 4: The remaining TMAH waste liquid in Step 3 and the low-concentration TMAH waste liquid generated in the developing section are collected in the fresh water tank. After being stirred, mixed, and homogenized in the fresh water tank, they are pumped to the first air flotation and sedimentation device. In the first air flotation and sedimentation device, the low-concentration TMAH waste liquid enters the reaction zone, and acid generated by the second purification device is added to the reaction zone to adjust the pH of the low-concentration TMAH waste liquid to neutral or acidic. Then it flows into the sedimentation zone and the air flotation zone to achieve the sedimentation and air flotation separation of precipitates such as photoresist and suspended solids, and the supernatant enters the second filtration device; the precipitate is dehydrated through equipment such as pressure filtration and drying, and then sent to the sludge treatment system of the enterprise's sewage treatment station for unified disposal; Step 5: The second filtration device consists of a sand filter and an ultrafiltration device, which further removes substances such as suspended solids and colloids in the supernatant. The filtered clear liquid flows into the second intermediate water tank for temporary storage and is then pumped to the second nanofiltration device; Step 6: The nanofiltration concentrated water containing photoresist, divalent ions, etc. in the low-concentration TMAH waste liquid separated by the second nanofiltration device is sent to the second air flotation and sedimentation device. The nanofiltration recovery rate is 90%, and 90% of the nanofiltration fresh water enters the reverse osmosis device; Step 7: The low-concentration TMAH waste liquid in the second air flotation and sedimentation device enters the reaction zone, and TMAH product generated by the second purification device is added to the reaction zone to adjust the pH of the low-concentration TMAH waste liquid to alkaline. Then it flows into the sedimentation zone and the air flotation zone to achieve the sedimentation and air flotation separation of precipitates such as divalent ions; the precipitate is dehydrated through equipment such as pressure filtration and drying, and then sent to the sludge treatment system of the enterprise's sewage treatment station for unified disposal; Step 8: The nanofiltration fresh water obtained by the second nanofiltration device is pumped into the reverse osmosis device. The reverse osmosis device concentrates the nanofiltration fresh water. The reverse osmosis recovery rate is 80%. 20% of the concentrated reverse osmosis concentrated water enters the second purification device, and 80% of the reverse osmosis fresh water enters the demineralized water tank and is used as the demineralized water for the production system for reuse; Step 9: The second purification device separates and purifies the 20% concentrated reverse osmosis concentrated water. The purification device consists of anion and cation exchange membranes, bipolar membranes, power supplies, electrodes, partitions, etc. TMAH products and acids are separated and purified through the directional migration of conductive ions. Part of the purified TMAH product is sent to the reuse tank, part of the TMAH product is sent to the second air flotation and sedimentation device to adjust the pH, and the generated acid is sent to the first air flotation and sedimentation device to adjust the pH; Step 10: The nanofiltration fresh water of the first nanofiltration device collected in the reuse tank and the TMAH product purified by the second purification device are mixed proportionally with high-purity water and are reused online after meeting the use concentration of TMAH.

[0037] Advantages of the present invention: The present invention solves the problem that high- and low-concentration TMAH waste liquids cannot be recycled online simultaneously by successively connecting a high-concentration waste liquid treatment subsystem and a low-concentration waste liquid treatment subsystem. At the same time, it realizes the purification of TMAH waste liquid into TMAH products and desalted water, and the online reuse in production, achieving the efficient recovery and zero discharge of TMAH waste liquid.

[0038] During the system treatment process of the present invention, no medicaments that pollute products are introduced, and the removal of pollutants in the TMAH waste liquid is achieved through the organic coupling of multiple physical and chemical methods, ensuring the online purity of the TMAH products and enabling better online reuse of the TMAH products.

[0039] The present invention realizes the zero discharge of TMAH waste liquid by coupling multiple physical and chemical treatment devices and utilizing the internal product recycling. Compared with the investment cost and treatment cost of the existing treatment technologies, it has made obvious and greater progress, achieving energy conservation, consumption reduction, and resource utilization.

[0040] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An online recycling zero-emission system for TMAH waste liquid, characterized in that: It includes a high-concentration waste liquid treatment subsystem and a low-concentration waste liquid treatment subsystem connected to each other; The high-concentration waste liquid treatment subsystem includes a first filtration device, a first nanofiltration device, and a first purification device connected in sequence; The low-concentration waste liquid treatment subsystem includes a first air flotation sedimentation device, a second filtration device, a second nanofiltration device, a reverse osmosis device, and a second purification device connected in sequence; The first purification device is connected to the air flotation sedimentation device; The first nanofiltration device, the first purification device, and the second purification device are all connected to a reuse tank; The high-concentration TMAH waste liquid is sent to the high-concentration waste liquid treatment subsystem. Suspended solids and colloids are removed by the first filtration device. Nanofiltration fresh water and nanofiltration concentrated water containing photoresist and divalent ions are separated by the first nanofiltration device. The nanofiltration concentrated water is purified by the first purification device to obtain purified TMAH products and low-concentration TMAH waste liquid. The nanofiltration fresh water and TMAH products are sent to the reuse tank, and the low-concentration TMAH waste liquid is sent to the low-concentration waste liquid treatment subsystem; The low-concentration TMAH waste liquid is separated into supernatant by the first air flotation sedimentation device. The supernatant is removed of suspended solids and colloids by the second filtration device. Nanofiltration fresh water and nanofiltration concentrated water containing photoresist and divalent ions are separated by the second nanofiltration device. The nanofiltration fresh water is desalted and concentrated by the reverse osmosis device to obtain reverse osmosis concentrated water, and purified TMAH products are obtained by the second purification device and sent to the reuse tank. High-purity water is added to the reuse tank to make the ratio in the reuse tank meet the use concentration of TMAH for online reuse.

2. The on-line recovery zero-emission system for TMAH waste liquid according to claim 1, wherein: It also includes a waste liquid collection tank, which is arranged at the front end of the first filtration device and is connected to the high-concentration TMAH waste liquid through a pipeline.

3. The on-line recycling zero-emission system for TMAH waste liquid according to claim 1, characterized in that: It also includes a concentrated water tank and a fresh water tank. The concentrated water tank is arranged between the first nanofiltration device and the first purification device, and the fresh water tank is arranged between the second purification device and the first air flotation sedimentation device; The nanofiltration concentrated water separated by the first nanofiltration device is temporarily stored in the concentrated water tank; The low-concentration TMAH waste liquid obtained by the high-concentration waste liquid treatment subsystem is temporarily stored in the fresh water tank; The fresh water tank is connected to external low-concentration TMAH waste liquid through a pipeline.

4. The on-line recovery and zero discharge system for TMAH waste liquid according to claim 3, characterized in that: The second nanofiltration device is also connected to a second air flotation sedimentation device, and the second air flotation sedimentation device is connected to the fresh water tank; The nanofiltration concentrated water containing photoresist and divalent ions separated by the second nanofiltration device is separated into supernatant and sediment by the second air flotation sedimentation device, and the supernatant flows back to the fresh water tank for re-treatment.

5. The on-line recycling zero-emission system for TMAH waste liquid according to claim 1, characterized in that: The reverse osmosis device is also connected to a desalted water tank; The nanofiltration fresh water separated by the second nanofiltration device is desalted and concentrated by the reverse osmosis device to obtain reverse osmosis fresh water, and the reverse osmosis fresh water is sent to the desalted water tank for storage.

6. The on-line recovery and zero-emission system for TMAH waste liquid according to claim 1, characterized in that: The second purification device is also connected to the first air flotation sedimentation device and the second air flotation sedimentation device, and the by-products obtained by purification are sent to the first air flotation sedimentation device and the second air flotation sedimentation device for secondary utilization.

7. An on-line recycling zero-emission system for TMAH waste liquid according to claim 1, characterized in that: Both the first filtration device and the second filtration device are provided with two or more stages of filters, and the filters include cartridge filters, bag filters, sand filters, microfiltration membrane filtration, and ultrafiltration membrane filtration.

8. The on-line recovery zero-emission system for TMAH waste liquid according to claim 1, wherein: Both the first nanofiltration device and the second nanofiltration device are provided with one-stage or multi-stage nanofiltration membranes for separating monovalent and divalent ions.

9. The on-line recycling zero-emission system for TMAH waste liquid according to claim 1, characterized in that: Both the first purification device and the second purification device include a power supply, electrodes, anion and cation exchange membranes, and partitions, and separate and purify the TMAH product through the directional migration of conductive ions.

10. The on-line recycling zero-emission system for TMAH waste liquid according to claim 1, characterized in that: Both the first air flotation and precipitation device and the second air flotation and precipitation device are provided with a reaction zone, a precipitation zone, an air flotation zone, and a chemical dosing device. The pH is adjusted through the chemical dosing device to separate the photoresist and divalent ions in the TMAH waste liquid.

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