A system and method for recycling and treating wastewater from integrated circuit LSRs.

Abstract

This invention discloses a wastewater reuse treatment system and method for integrated circuit LSRs, belonging to the field of water treatment technology. The wastewater treatment system of this invention, according to the process flow, includes a collection tank, a pH adjustment tank, a first intermediate water tank, a multi-media filter, a carbon-based filter, a first heat exchanger, a second intermediate water tank, a cation exchange tower, an anion exchange tower, a water supply tank, a microfiltration filter, and a second heat exchanger. This wastewater treatment system and method are highly efficient, have a simple system structure, occupy a small area, cause no secondary pollution to the environment, and are easy to promote and apply on a large scale in industrial applications. In particular, the use of two layers of lightweight filter media in the multi-media filter improves the filtration effect and saves on high-resistance drainage systems; the carbon-based material in the carbon-based filter can activate persulfate, and the hot wastewater can also activate persulfate, resulting in a synergistic effect that reduces the amount of persulfate added and achieves higher efficiency in degrading organic matter.

Description

Technical Field

[0001] This invention belongs to the field of water treatment technology, specifically relating to an integrated circuit LSR wastewater reuse treatment system and method. Background Technology

[0002] The plasma water washing local scrubber equipment is used to remove PFC greenhouse gases and toxic and harmful gases such as CF4, NF3, SF6, C2F6, CHF3, and CH2F2 used or generated in wafer fabrication processes such as integrated circuit dry etch, thin film, and diffusion. Nitrogen gas is ionized into plasma under the action of a strong current, and the resulting high-temperature flame decomposes the waste gas. Finally, after two stages of water washing, the waste gas is discharged into the atmosphere. The chemical substances in the waste gas dissolve in the water, producing LSR wastewater.

[0003] Currently, integrated circuit factories typically discharge LSR wastewater into wastewater ponds for treatment along with other wastewater, discharging it only after it meets standards. LSR wastewater accounts for approximately 10-15% of the total wastewater volume, which is relatively large. Compared to other wastewater, LSR wastewater has low levels of total organic carbon (TOC), conductivity, fluoride ions, and turbidity, and its pollutant composition is not complex. Furthermore, the water used by LSR equipment does not have high requirements for water quality indicators such as conductivity, fluoride ions, and turbidity. To conserve water resources, collecting and treating LSR wastewater separately before supplying it to LSR equipment is the most economical and reasonable approach. Summary of the Invention

[0004] The purpose of this invention is to provide a treatment system and method that has high efficiency in treating integrated circuit LSR wastewater, simple system structure, small footprint, no secondary pollution to the environment, and is easy to promote and apply on a large scale in industrial applications.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] The integrated circuit LSR wastewater reuse treatment system of the present invention includes, in sequence according to the process flow:

[0007] A collection tank receives wastewater from the LSR device and adjusts the water volume.

[0008] A pH adjustment tank located downstream of and connected to the collection tank, wherein the pH adjustment tank adjusts the pH of the wastewater;

[0009] A first intermediate water tank located downstream of and connected to the pH adjustment tank;

[0010] A multi-media filter located downstream of and connected to the first intermediate water tank, the multi-media filter removes colloidal particles and suspended solids with a particle size greater than 0.5 μm from the wastewater;

[0011] A carbon-based filter located downstream of and connected to the multi-media filter, the carbon-based filter degrades organic matter in the wastewater;

[0012] A first heat exchanger located downstream of and connected to the carbon-based filter exchanges heat with the wastewater.

[0013] A second intermediate water tank located downstream of the first heat exchanger and connected to the first heat exchanger;

[0014] A cation exchange tower located downstream of and connected to the second intermediate water tank, the cation exchange tower being used to remove cations from wastewater;

[0015] An anion exchange tower located downstream of and connected to the cation exchange tower is used to remove anions from wastewater.

[0016] A water supply tank located downstream of and connected to the anion exchange tower;

[0017] A microfiltration filter located downstream of and connected to the water supply tank is used to remove impurity particles larger than 0.1 μm from the wastewater to obtain recyclable water.

[0018] And a second heat exchanger located downstream of and connected to the microfiltration filter, the second heat exchanger exchanging heat with the water to meet the water temperature requirements of the LSR equipment.

[0019] Furthermore, the pH adjustment tank adjusts the pH of the wastewater by adding acid or alkali, so that the pH of the effluent from the pH adjustment tank is 9-10.

[0020] Furthermore, the multi-media filter removes colloidal particles and suspended solids in wastewater with a particle size greater than 0.5 μm by adding a coagulant to the pipe connecting the first intermediate water tank and the multi-media filter; and the multi-media filter is equipped with lightweight filter media that is lighter than water, wherein the lightweight filter media consists of granular filter media and fiber filter media arranged sequentially from bottom to top.

[0021] Furthermore, the coagulant is polyaluminum chloride;

[0022] Furthermore, the granular filter media is polystyrene granular material, and the fiber filter media is fiber bundle filter media;

[0023] Furthermore, a bottom water supply system is installed at the bottom of the tank of the multi-media filter. This system is a porous annular network with equally spaced openings at the top. One end of the bottom water supply system is connected to the outlet end of the inlet pipe of the multi-media filter, and the inlet end of the inlet pipe is connected to the outlet pipe of the first intermediate water tank. An electric valve is installed on the inlet pipe. The other end of the bottom water supply system is connected to the backwash drain pipe of the multi-media filter, and an electric valve is installed on the backwash drain pipe. The system consists of granular filter media and fiber filter media arranged sequentially from bottom to top, with the lower layer of granular filter media having a lower density than the upper layer of fiber filter media. An interception net is installed above the fiber filter media, and the fiber filter media is fixed to the interception net. A top drainage system is installed above the interception net and at the top of the tank. The top drainage system is a porous annular pipe network with equally spaced openings at the bottom. One end of the top drainage system is connected to the inlet end of the drain pipe of the multi-media filter. The drain pipe is equipped with a drain electric valve, and the outlet end of the drain pipe is connected to the inlet pipe of the carbon-based filter.

[0024] Furthermore, the porous annular pipe network includes a circular annular pipe, a main horizontal pipe, and a main vertical pipe. The main horizontal pipe and the main vertical pipe are arranged vertically and are connected at their intersection point, which is located at the center of the circular annular pipe. Both ends of the main horizontal pipe and the main vertical pipe are connected to the circular annular pipe.

[0025] Furthermore, the porous annular pipe network also includes several secondary longitudinal pipes, which are arranged parallel to the main longitudinal pipe and perpendicular to the main horizontal pipe, and both ends are connected to the annular pipe, and the intersections with the main horizontal pipe are also connected.

[0026] Furthermore, the carbon-based filter degrades organic matter in wastewater by adding persulfate into the pipe connecting the multi-media filter and the carbon-based filter; and carbon-based material is installed inside the carbon-based filter; the temperature of the wastewater entering the carbon-based filter is 40-70℃.

[0027] Furthermore, the persulfate is permonosulfate (PMS) or perdisulfate (PDS), and the dosage is 1-30 mg / L;

[0028] Furthermore, the carbon-based material is activated carbon particles or bio-activated carbon particles;

[0029] Furthermore, the LSR wastewater is the wastewater obtained by washing the exhaust gas after combustion in a combustion furnace, with a temperature of 40-70℃.

[0030] The integrated circuit LSR wastewater reuse treatment process of the present invention, using the above-mentioned integrated circuit LSR wastewater reuse treatment system, includes the following steps:

[0031] Wastewater from S01 and LSR equipment enters the collection tank;

[0032] S02. The effluent from the collection tank enters the pH adjustment tank, where acid or alkali is added.

[0033] S03, the effluent from the pH adjustment tank enters the first intermediate water tank;

[0034] S04. The effluent from the first intermediate water tank is pressurized by a water pump and enters the multi-media filter. Coagulant is added into the pipe connecting the first intermediate water tank and the multi-media filter.

[0035] S05. Water from the multi-media filter enters the carbon-based filter, and persulfate is added to the pipe connecting the multi-media filter and the carbon-based filter.

[0036] S06. Water from the carbon-based filter enters the first heat exchanger;

[0037] S07, the water outlet of the first heat exchanger enters the second intermediate water tank;

[0038] S08. The effluent from the second intermediate water tank is pressurized by a water pump and enters the cation exchange tower.

[0039] S09. The effluent from the cation exchange tower enters the anion exchange tower;

[0040] S10, the effluent from the anion exchange tower enters the water supply tank;

[0041] S11. Water from the water supply tank is pressurized by a water pump and enters the microfiltration filter;

[0042] S12. Water from the microfiltration filter enters the second heat exchanger;

[0043] S13, the water outlet of the second heat exchanger is supplied to the LSR equipment.

[0044] Furthermore, step S14 is also included:

[0045] S14. Clean the particulate and fiber filter media of the carbon-based filter;

[0046] The cleaning method is as follows: close the electric valves on the inlet and outlet pipes, and open the electric valve on the backwash drain pipe. The water stored in the upper space of the intercepting net flows downwards towards the granular and fiber filter media under the action of gravity. Colloidal particles and tiny suspended solids in the filter media flow downwards with the backwash water and enter the bottom water supply system through the hole at the top of the bottom water supply system. The water is discharged from the backwash drain pipe and discharged to the drainage facility. After the granular and fiber filter media have been backwashed, close the electric valve on the backwash drain pipe, open the electric valve on the outlet pipe, and open the electric valve on the inlet pipe to start the next filtration cycle.

[0047] The principles of this invention mainly include the filtration principle of multi-media filters and the principle of carbon-based filters degrading organic matter.

[0048] The filtration principle of a multi-media filter is as follows: Granular and fiber filter media each have their own filtration characteristics: granular media offers deep filtration, while fiber filter media provides high filtration precision. Combining these two types of media in a single filtration device, with the lower density of the granular filter media compared to the upper layer, creates an upward buoyancy that compresses the upper fiber filter layer, thus forming a unique double-layer composite filter media structure. During filtration, raw water first passes through the granular filter media to remove colloidal particles and fine suspended solids larger than 1 μm, then enters the fiber filter media to remove colloidal particles and fine suspended solids larger than 0.5 μm, improving water purification efficiency. During backwashing, water stored in the upper space of the filter screen stretches the granular and fiber filter media layers under gravity, effectively washing them.

[0049] The principle of carbon-based filters in degrading organic matter is as follows: before wastewater enters the carbon-based filter, persulfate is added to the pipe connecting the multi-media filter and the carbon-based filter. Persulfate includes permonosulfate (PMS) (HSO5). - ) and persulfate PDS (S2O8) 2- Persulfate contains O-O bonds and is a derivative of H₂O₂. The serrated edges, surface defects, and delocalized π electrons on the surface of carbon-based materials exhibit high reactivity. Simultaneously, oxygen-containing functional groups on the surface of carbon-based materials, such as ketone hydroxyl, hydroxyl, and carboxyl groups, can combine with PMS or PDS to form -C=OHO-OSO₃, thereby promoting the breaking of the O-O bonds and generating persulfate radicals (SO₄). -· (PDS) or persulfate radicals and hydroxyl radicals OH · (PMS). Free radicals can mineralize organic matter into CO2 and H2O, or convert it into small molecule organic matter. On the other hand, LSR wastewater is wastewater washed after the exhaust gas has been burned at high temperature in a combustion furnace. The wastewater temperature is relatively high, usually 40-70℃. The heat energy generated by the high-temperature wastewater can break the O2O bonds in persulfate, generating persulfate free radicals SO4. -· (PDS) or persulfate radicals and hydroxyl radicals OH · (PMS). In addition, carbon-based materials can activate persulfate, and hot wastewater can also activate persulfate. The two can produce a synergistic effect, reducing the amount of persulfate added and improving the degradation of organic matter.

[0050] Compared with the prior art, the present invention has the following beneficial effects:

[0051] 1) The integrated circuit LSR wastewater reuse treatment system of the present invention uses a carbon-based filter that has degradation properties.

[0052] Organic matter function. Carbon-based materials can activate persulfate, and thermal wastewater can also activate persulfate. The two can produce a synergistic effect, reducing the amount of persulfate added and achieving higher efficiency in degrading organic matter.

[0053] 2) The integrated circuit LSR wastewater reuse treatment system of the present invention uses persulfate which does not cause secondary pollution to the environment, is inexpensive and readily available, non-toxic and harmless, and easy to use.

[0054] 3) The integrated circuit LSR wastewater reuse treatment system of the present invention uses a carbon-based filter with disinfection function. Since the free radicals generated by the activation of persulfate can inactivate bacteria and microorganisms, the wastewater is disinfected. It is not necessary to add disinfectants such as sodium hypochlorite before the multi-media filter according to conventional processes, which is low-carbon and environmentally friendly.

[0055] 4) The integrated circuit LSR wastewater reuse treatment system of the present invention uses a multi-media filter with better filtration effect, saves the high-resistance drainage system, saves the backwash water pump, and reduces operating costs.

[0056] 5) The integrated circuit LSR wastewater reuse treatment system of the present invention uses a multi-media filter that cleverly combines two filter media that are lighter than water. Compared with the existing single-layer filter media of multi-media filters, it can perform deep filtration, resulting in lower turbidity of the effluent and a corresponding reduction in the content of organic matter and salts in the water. Therefore, it can reduce the organic matter load of the subsequent carbon-based filter, reduce the amount of persulfate added, and at the same time reduce the ion load of the anion and cation exchange towers, reduce the amount of acid and alkali reagents used during filter media backwashing, and save operating costs.

[0057] 6) In the integrated circuit LSR wastewater reuse treatment system of the present invention, the carbon-based filter can use the activated carbon that has failed in the activated carbon filter pool in the pure water treatment process of the integrated circuit factory, so that the waste can be reused.

[0058] 7) The integrated circuit LSR wastewater reuse treatment method of the present invention is convenient for large-scale industrial promotion and application. Attached Figure Description

[0059] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the specific embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0060] Figure 1 This is a process flow diagram of the integrated circuit LSR wastewater reuse treatment system of the present invention;

[0061] Figure 2This is a schematic diagram of the structure of the carbon-based filter in the integrated circuit LSR wastewater reuse treatment system of the present invention;

[0062] Figure 3 This is a schematic diagram of the bottom water supply system and the top drainage system of the carbon-based filter in the integrated circuit LSR wastewater reuse treatment system of the present invention;

[0063] Figure 4 The graph shows the degradation effect of three systems on TOC in water at 60°C: water, carbon-based material, and water + carbon-based material at 60°C, when different doses of persulfate were added, in Comparative Example 1 of the present invention.

[0064] Explanation of reference numerals in the attached figures:

[0065] 1. Collection tank; 2. pH adjustment tank; 3. First intermediate water tank; 4. Multi-media filter; 5. Carbon-based filter; 6. First heat exchanger; 7. Second intermediate water tank; 8. Cation exchange tower; 9. Anion exchange tower; 10. Water supply tank; 11. Microfiltration filter; 12. Second heat exchanger;

[0066] 401. Tank body; 402. Bottom water supply system; 403. Inlet pipe; 404. Backwash drain pipe; 405. Granular filter media; 406. Fiber filter media; 407. Interception net; 408. Top drainage system; 409. Outlet pipe; 410. Outlet pipe electric valve; 411. Inlet pipe electric valve; 412. Backwash drain pipe electric valve. Detailed Implementation

[0067] To further understand the present invention, preferred embodiments of the present invention are described below. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, and not for limiting the scope of the claims of the present invention.

[0068] like Figure 1-2 As shown, the integrated circuit LSR wastewater reuse treatment system of the present invention includes, in sequence according to the process flow: collection tank 1, pH adjustment tank 2, first intermediate water tank 3, multi-media filter 4, carbon-based filter 5, first heat exchanger 6, second intermediate water tank 7, cation exchange tower 8, anion exchange tower 9, water supply tank 10, microfiltration filter 11, and second heat exchanger 12.

[0069] Wastewater from the LSR equipment sequentially enters collection tank 1 and pH adjustment tank 2. Acid or alkali is added to pH adjustment tank 2 to adjust the pH of the wastewater, making the pH of the wastewater flowing out of pH adjustment tank 2 9-10. The effluent from pH adjustment tank 2 enters the first intermediate water tank 3, and after being pressurized by a water pump, the wastewater enters multi-media filter 4. Before entering multi-media filter 4, coagulant is added to the inlet pipe 403 of multi-media filter 4. The coagulant causes suspended particles in the wastewater to aggregate and increase in size, forming flocs. Wastewater enters the bottom water supply system 402 (a porous annular network with equally spaced openings at the top) through the inlet pipe 403, flows out from the openings at the top of the bottom water supply system 402, and passes upward through the granular filter media 405 and fiber filter media 406 for filtration. Colloidal particles and tiny suspended solids with a particle size greater than 0.5μm in the wastewater are removed. The filtered wastewater passes through the interceptor screen 407 and flows upward through the openings at the bottom of the top drainage system 408 (a porous annular network with equally spaced openings at the bottom), and is discharged from the outlet pipe 409. After filtration for a period of time, the number of colloidal particles and tiny suspended solids in the granular filter media 405 and fiber filter media 406 increases, and the quality of the effluent decreases. The granular filter media 405 and fiber filter media 406 need to be backwashed. Close the inlet valve 411 on the inlet pipe 403 and the outlet valve 410 on the outlet pipe 409. Open the backwash drain valve 412 on the backwash drain pipe 404. Water stored in the upper space of the interceptor net 407 flows downwards under gravity toward the granular filter media 405 and the fiber filter media 406. The filter layers of the granular filter media 405 and the fiber filter media 406 are stretched. Colloidal particles and tiny suspended solids in the granular filter media 405 and the fiber filter media 406 flow downwards with the backwash water, enter the bottom water supply system 402 through the hole at the top of the bottom water supply system 402, and are discharged from the backwash drain pipe 404. The backwash water is discharged to the drainage facility. After the granular filter media 405 and the fiber filter media 406 have been backwashed, close the backwash drain valve 412, open the outlet valve 410 on the outlet pipe 409, and open the inlet valve 411 on the inlet pipe 403 to begin the next filtration cycle. The effluent from the multi-media filter 4 enters the carbon-based filter 5. Before entering the carbon-based filter 5, persulfate is added to the pipe connecting the multi-media filter 4 and the carbon-based filter 5 at a dosage of 1-30 mg / L. The carbon-based material can activate the persulfate, and the hot wastewater (LSR wastewater is the wastewater washed after high-temperature combustion of exhaust gas in a combustion furnace; the wastewater temperature is relatively high, usually 40-70℃) can also activate the persulfate, generating strong oxidizing free radicals such as persulfate ions, which efficiently degrade organic molecules. At the same time, because free radicals can inactivate bacteria and microorganisms, the wastewater is disinfected. The effluent from the carbon-based filter 5 enters the first heat exchanger 6, which heats the water to 25℃. The effluent from the first heat exchanger 6 enters the second intermediate water tank 7, and the effluent from the second intermediate water tank 7 is pressurized by a water pump to the cation exchange tower 8, where strong acid cation exchange resin removes cations from the wastewater.The effluent from cation exchange tower 8 enters anion exchange tower 9, where strong base anion exchange resin removes anions from the wastewater. The effluent from anion exchange tower 9 then enters a water supply tank 10. From the water supply tank 10, the effluent is pressurized by a pump and sent to a microfiltration filter 11. The microfiltration filter 11 removes impurities larger than 0.1 μm from the water. The effluent from the microfiltration filter 11 then enters a second heat exchanger 12, which heats the water to the temperature required by the LSR equipment.

[0070] like Figure 3 As shown, the porous annular pipe network of the present invention includes a circular annular pipe, a main horizontal pipe, a main longitudinal pipe, and several secondary longitudinal pipes. The main horizontal pipe and the main longitudinal pipe are arranged perpendicularly, and their intersection point is connected and located at the center of the circular annular pipe. Both ends of the main horizontal pipe and the main longitudinal pipe are connected to the circular annular pipe. The several secondary longitudinal pipes are arranged parallel to the main longitudinal pipe and perpendicular to the main horizontal pipe, and both ends are connected to the circular annular pipe. They are also connected at their intersection points with the main horizontal pipe. The several secondary longitudinal pipes are generally symmetrical with respect to the main longitudinal pipe. For the bottom water supply system 402, the holes of the porous annular pipe network are located at the top; for the top water supply system 408, the holes of the porous annular pipe network are located at the bottom.

[0071] The integrated circuit LSR wastewater reuse treatment process of the present invention includes the following steps: wastewater from the LSR equipment enters a collection tank 1; effluent from the collection tank 1 enters a pH adjustment tank 2, and acid or alkali is added to the pH adjustment tank 2; effluent from the pH adjustment tank 2 enters a first intermediate water tank 3; effluent from the first intermediate water tank 3 is pressurized by a water pump and enters a multi-media filter 4, and coagulant is added to the pipe connecting the first intermediate water tank 3 and the multi-media filter 4; effluent from the multi-media filter 4 enters a carbon-based filter 5, and coagulant is added to the pipe connecting the multi-media filter 4 and the carbon-based filter 5. Persulfate is added to the pipeline of carbon-based filter 5; the effluent from carbon-based filter 5 enters the first heat exchanger 6; the effluent from the first heat exchanger 6 enters the second intermediate water tank 7; the effluent from the second intermediate water tank 7 is pressurized by a water pump and enters the cation exchange tower 8; the effluent from the cation exchange tower 8 enters the anion exchange tower 9; the effluent from the anion exchange tower 9 enters the water supply tank 10; the effluent from the water supply tank 10 is pressurized by a water pump and enters the microfiltration filter 11; the effluent from the microfiltration filter 11 enters the second heat exchanger 12; the effluent from the second heat exchanger 12 is supplied to the LSR equipment.

[0072] The terminology used in this invention generally has the meanings commonly understood by those skilled in the art, unless otherwise stated.

[0073] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to embodiments.

[0074] In the following embodiments, various processes and methods not described in detail are conventional methods known in the art. Unless otherwise specified, the materials, reagents, apparatus, instruments, equipment, etc., used in the following embodiments are commercially available.

[0075] Comparative Example 1

[0076] This embodiment compares the degradation rate of TOC under three systems: persulfate activated at 60°C water, persulfate activated with carbon-based materials, and persulfate activated by both water and carbon-based materials at 60°C, at different persulfate dosages, to demonstrate that persulfate activated by both water and carbon-based materials at 60°C has a synergistic effect on TOC degradation.

[0077] Experimental setup: raw water tank, carbon-based filter, dosing device.

[0078] Experimental Procedures: Option 1: Prepare raw water with a specific TOC concentration in the raw water tank, then introduce it into the carbon-based filter. Before entering the filter, add persulfate to the pipe connecting the raw water tank and the carbon-based filter. The raw water is then discharged after exiting the carbon-based filter. Option 2: Prepare raw water with a specific TOC concentration at 60℃ in the raw water tank, then introduce it into the carbon-based filter. The raw water is then discharged after exiting the carbon-based filter. Option 3: Prepare raw water with a specific TOC concentration at 60℃ in the raw water tank, then introduce it into the carbon-based filter. Before entering the carbon-based filter, add persulfate to the pipe connecting the raw water tank and the carbon-based filter. The raw water is then discharged after exiting the carbon-based filter.

[0079] Test parameters: TOC 5 mg / L, carbon-based filter processing capacity 1 m³ / L. 3 / h, the persulfate dosages were 5 mg / L, 10 mg / L, 15 mg / L, 20 mg / L, 25 mg / L, and 30 mg / L, respectively.

[0080] Experimental steps:

[0081] Option 1:

[0082] Prepare water with a TOC content of 5 mg / L in the raw water tank, adjust the pH of the solution to 9-10 using acid or alkali, and stir evenly.

[0083] Add 5 mg / L, 10 mg / L, 15 mg / L, 20 mg / L, 25 mg / L, and 30 mg / L of persulfate to the pipes connecting the raw water tank and the carbon-based filter using a chemical dosing device.

[0084] Water passes through a carbon-based filter;

[0085] Take a water sample after treatment with a carbon-based filter and use Na2SO3 at a concentration of 500 mg / L as a quenching agent to terminate the reaction.

[0086] The TOC concentration in the treated water sample was measured.

[0087] Option 2:

[0088] Water with a temperature of 60℃ and a TOC content of 5mg / L to be treated is prepared in the raw water tank. The pH of the solution is adjusted to 9-10 using acid or alkali and stirred evenly.

[0089] Water passes through a carbon-based filter;

[0090] Take a water sample after treatment with a carbon-based filter and use Na2SO3 at a concentration of 500 mg / L as a quenching agent to terminate the reaction.

[0091] The TOC concentration in the treated water sample was measured.

[0092] Option 3:

[0093] Water with a temperature of 60℃ and a TOC content of 5mg / l is prepared in the raw water tank. The pH of the solution is adjusted to 9-10 using acid or alkali and stirred evenly.

[0094] Add 5 mg / L, 10 mg / L, 15 mg / L, 20 mg / L, 25 mg / L, and 30 mg / L of persulfate to the pipes connecting the raw water tank and the carbon-based filter using a chemical dosing device.

[0095] Water passes through a carbon-based filter;

[0096] Take a water sample after treatment with a carbon-based filter and use Na2SO3 at a concentration of 500 mg / L as a quenching agent to terminate the reaction.

[0097] The TOC concentration in the treated water sample was measured.

[0098] Table 1 shows the degradation effects of three systems—water at 60℃, carbon-based materials, and water at 60℃ + carbon-based materials—on TOC in water. The degradation effects vary with the amount of persulfate used. Figure 4 As shown in the figure. Where C0 is the initial concentration of the TOC solution, and C is the concentration after treatment.

[0099] Table 1. Degradation effect of different systems on TOC in water

[0100]

[0101] From Table 1 and Figure 4 It is known that when persulfate is added, 60°C water alone and carbon-based materials alone have a certain degradation effect on TOC. The 60°C water + carbon-based material system significantly improves the effect. When the dosage is 30 mg / L, the TOC removal rate can reach 97%. This comparative example confirms that when persulfate is added, the provided hot wastewater and carbon-based materials have a synergistic effect, and the method of generating free radicals to rapidly degrade TOC in water has a better degradation effect.

[0102] Example 1

[0103] LSR wastewater quality from the wood semiconductor plant: TOC 5 mg / L, temperature 55℃, conductivity 1200 μS / cm, F - 110 mg / L, turbidity 12 NTU, pH 2-11.

[0104] Wastewater enters collection tank 1, and the effluent from collection tank 1 enters pH adjustment tank 2. Acid or alkali is added to pH adjustment tank 2 to adjust the pH of the water to 9. The effluent from pH adjustment tank 2 enters the first intermediate water tank 3, and the effluent from the first intermediate water tank 3 is pressurized by a water pump and enters the multi-media filter 4. Before the effluent enters the multi-media filter 4, polyaluminum chloride, a coagulant, is added to the pipe connecting the first intermediate water tank 3 and the multi-media filter 4. The suspended particles in the wastewater aggregate and become larger, forming flocs. Wastewater enters the bottom water supply system 402 from the inlet pipe 403 and flows out from the hole at the top of the bottom water supply system 402. It passes upward through polystyrene granular filter media and fiber bundle filter media in sequence. Colloidal particles and tiny suspended solids with a particle size greater than 0.5μm in the water are removed. The filtered wastewater passes through the interception net 407 and enters the top drainage system 408 from the hole at the bottom of the top drainage system 408, and is discharged from the outlet pipe 409. The multi-media filter 4 produces effluent turbidity <0.1 NTU. While reducing effluent turbidity, it also reduces organic matter and sulfur in the water. - The content of substances such as salts also decreases to some extent. After filtration for a period of time, the amount of colloidal particles and fine suspended solids in the two layers of filter media increases, the quality of the effluent decreases, and the filter media needs to be backwashed. Close the inlet pipe electric valve 411 on the inlet pipe 403 and the outlet pipe electric valve 410 on the outlet pipe 409, and open the backwash drain pipe electric valve 412 on the backwash drain pipe 404. The water stored in the upper space of the interception net 407 flows downwards towards the filter media under the action of gravity. The colloidal particles and fine suspended solids in the filter media flow downwards with the water flow, enter the bottom water supply system 402 through the hole at the bottom of the bottom water supply system 402, and are discharged from the backwash drain pipe 404. The backwash water is discharged to the drainage facility. After the filter media backwashing is completed, close the backwash drain electric valve 412, open the outlet pipe electric valve 410 on the outlet pipe 409, and open the inlet pipe electric valve 411 on the inlet pipe 403 to start the next filtration cycle.

[0105] Wastewater enters carbon-based filter 5 from multi-media filter 4. Before entering carbon-based filter 5, persulfate is added to the pipe connecting multi-media filter 4 and carbon-based filter 5 at a dosage of 17 mg / L. The carbon-based material activates the persulfate; thermal activation of the persulfate generates strong oxidizing free radicals such as persulfate ions, which efficiently degrade organic molecules. Simultaneously, the free radicals inactivate bacteria and microorganisms, disinfecting the wastewater. The effluent from carbon-based filter 5 enters the first heat exchanger 6, which heats the water to 25°C. The effluent from the first heat exchanger 6 enters the second intermediate water tank 7, and the effluent from the second intermediate water tank 7 is pressurized by a pump to the cation exchange tower 8. The packing material in the cation exchange tower 8 is a strong acid cation resin, which can degrade sodium in the water. + K + Ca 2+ and Mg 2+ Cations are converted to H + The cation exchanger removes cations. The effluent from cation exchanger 8 enters anion exchanger 9, which is filled with strong base anion exchange resin to remove Cl- from the water. - SO4 2- HCO3 - CO3 2- Anions are exchanged. The effluent from the anion exchange tower 9 enters the water supply tank 10. The effluent from the water supply tank 10 is pressurized by a water pump and sent to the microfiltration filter 11. The microfiltration filter 11 removes impurities larger than 0.1μm from the water. The effluent from the microfiltration filter 11 enters the second heat exchanger 12, which heats the water to the 25°C required by the LSR equipment.

[0106] After testing, the water quality indicators after treatment by the process of this invention are: temperature 25℃, conductivity <100μs / cm, F - <5mg / l, turbidity <1NTU, pH 9-10, meeting the influent water quality requirements of LSR equipment.

[0107] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A wastewater reuse and treatment system for integrated circuit LSRs, characterized in that, The process flow includes, in sequence: Collection tank (1), the collection tank (1) receives wastewater from LSR equipment and adjusts the water volume; A pH adjustment tank (2) is located downstream of the collection tank (1) and connected to the collection tank (1), the pH adjustment tank (2) adjusting the pH of the wastewater; A first intermediate water tank (3) located downstream of the pH adjustment tank (2) and connected to the pH adjustment tank (2); A multi-media filter (4) is located downstream of the first intermediate water tank (3) and connected to the first intermediate water tank (3). The multi-media filter (4) removes colloidal particles and suspended solids with a particle size greater than 0.5 μm from the wastewater. A bottom water supply system (402) is provided at the bottom of the tank (401) of the multi-media filter (4). The bottom water supply system (402) is a porous annular pipe network with equally spaced openings at the top. One end of the bottom water supply system (402) is connected to the outlet end of the inlet pipe (403) of the multi-media filter (4). The inlet end of (403) is connected to the outlet pipe of the first intermediate water tank (3), and an inlet pipe electric valve (411) is provided on the inlet pipe (403); the other end of the bottom water supply system (402) is connected to the filter media backwash drain pipe (404) of the multi-media filter (4), and a backwash drain pipe electric valve (412) is provided on the filter media backwash drain pipe (404); granular filter media (405) and fiber filter media (406) are arranged sequentially from bottom to top above the bottom water supply system (402), and the granular filter media (405) and fiber filter media (406) are arranged sequentially from bottom to top. The filter media (405) is lighter than water and has a lower density than the upper fiber filter media (406). A screen (407) is installed above the fiber filter media (406), and the fiber filter media (406) is fixed to the screen (407). A top drainage system (408) is installed above the screen (407) and at the top of the tank (401). The top drainage system (408) is a porous annular network with equally spaced openings at the bottom. One end of the top drainage system (408) is connected to the inlet end of the outlet pipe (409) of the multi-media filter (4). The water outlet pipe (409) is equipped with an electric valve (410), and the water outlet end of the water outlet pipe (409) is connected to the water inlet pipe of the carbon-based filter (5). The porous annular pipe network includes a circular annular pipe, a main horizontal pipe and a main vertical pipe. The main horizontal pipe and the main vertical pipe are arranged vertically and are connected at their intersection and located at the center of the circular annular pipe. Both ends of the main horizontal pipe and the main vertical pipe are connected to the circular annular pipe. The network also includes several secondary vertical pipes. The secondary vertical pipes are parallel to the main vertical pipe and perpendicular to the main horizontal pipe, and both ends are connected to the circular annular pipe. The intersections with the main horizontal pipe are also connected. A carbon-based filter (5) located downstream of the multi-media filter (4) and connected to the multi-media filter (4) is provided with carbon-based materials and degrades organic matter in wastewater. A first heat exchanger (6) located downstream of and connected to the carbon-based filter (5) exchanges heat with the wastewater. A second intermediate water tank (7) is located downstream of the first heat exchanger (6) and connected to the first heat exchanger (6); A cation exchange tower (8) located downstream of and connected to the second intermediate water tank (7) is used to remove cations from the wastewater. An anion exchange tower (9) is located downstream of the cation exchange tower (8) and connected to the cation exchange tower (8). The anion exchange tower (9) is used to remove anions from wastewater. A water supply tank (10) located downstream of the anion exchange tower (9) and connected to the anion exchange tower (9). A microfiltration filter (11) located downstream of the water supply tank (10) and connected to the water supply tank (10) is used to remove impurity particles with a particle size greater than 0.1 μm from the wastewater to obtain water that can be recycled. And a second heat exchanger (12) located downstream of the microfiltration filter (11) and connected to the microfiltration filter (11), the second heat exchanger (12) exchanges heat with the water to meet the water temperature requirements of the LSR equipment; Persulfate is added to the pipe connecting the multi-media filter (4) and the carbon-based filter (5); The carbon-based material is activated carbon particles or bio-activated carbon particles. The LSR wastewater is the wastewater from the washing of waste gas after combustion in a combustion furnace, at a temperature of 40-70℃.

2. The integrated circuit LSR wastewater reuse treatment system according to claim 1, characterized in that, The pH adjustment tank (2) adjusts the pH of the wastewater by adding acid or alkali, so that the pH of the effluent from the pH adjustment tank (2) is 9-10.

3. The integrated circuit LSR wastewater reuse treatment system according to claim 1, characterized in that, The multi-media filter (4) removes colloidal particles and suspended solids with a particle size greater than 0.5 μm from wastewater in the following manner: Add coagulant to the pipe connecting the first intermediate water tank (3) and the multi-media filter (4).

4. The integrated circuit LSR wastewater reuse treatment system according to claim 3, characterized in that, The coagulant is polyaluminum chloride; And / or, the particulate filter media is polystyrene particulate material; And / or, the fiber filter media is a fiber bundle filter media.

5. The integrated circuit LSR wastewater reuse treatment system according to claim 1, characterized in that, The carbon-based filter (5) degrades organic matter in wastewater in the following way: The temperature of the wastewater entering the carbon-based filter (5) is 40-70℃.

6. The integrated circuit LSR wastewater reuse treatment system according to claim 1, characterized in that, The persulfate is permonosulfate or perdisulfate, and the dosage is 1-30 mg / L.

7. A process for treating and reusing wastewater from integrated circuit LSRs, characterized in that, The integrated circuit LSR wastewater reuse treatment system according to any one of claims 1-6 includes the following steps: S01, Wastewater from LSR equipment enters collection tank (1); S02. The effluent from the collection tank (1) enters the pH adjustment tank (2), and acid or alkali is added to the pH adjustment tank (2). S03, pH adjustment tank (2) effluent enters the first intermediate water tank (3); S04. The water effluent from the first intermediate water tank (3) is pressurized by a water pump and enters the multi-media filter (4). Coagulant is added into the pipe connecting the first intermediate water tank (3) and the multi-media filter (4). S05. The water from the multi-media filter (4) enters the carbon-based filter (5), and persulfate is added to the pipe connecting the multi-media filter (4) and the carbon-based filter (5). S06, water from the carbon-based filter (5) enters the first heat exchanger (6); S07, the water from the first heat exchanger (6) enters the second intermediate water tank (7); S08. The water from the second intermediate water tank (7) is pressurized by a water pump and enters the cation exchange tower (8). S09, The effluent from the cation exchange tower (8) enters the anion exchange tower (9); S10, the effluent from the anion exchange tower (9) enters the water supply tank (10). S11. Water from the water supply tank (10) is pressurized by a water pump and enters the microfiltration filter (11). S12, water from the microfiltration filter (11) enters the second heat exchanger (12); S13, the water from the second heat exchanger (12) is supplied to the LSR equipment.

8. The integrated circuit LSR wastewater reuse treatment process according to claim 7, employing the integrated circuit LSR wastewater reuse treatment system according to claim 4, characterized in that, It also includes, S14. Clean the granular filter media (405) and fiber filter media (406) of the multi-media filter (4); the cleaning method is as follows: close the inlet pipe electric valve (411) on the inlet pipe (403) and the outlet pipe electric valve (410) on the outlet pipe (409), open the backwash drain pipe electric valve (412) on the backwash drain pipe (404), and the water stored in the upper space of the interception net (407) flows downward towards the granular filter media (405) and fiber filter media (406) under the action of gravity. Colloidal particles and suspended solids in the fiber filter media (406) are carried downward by the backwash water and enter the bottom water supply system (402) through the hole at the top of the bottom water supply system (402). They are discharged from the backwash drain pipe (404) and the backwash water is discharged to the drainage facility. After the granular filter media (405) and fiber filter media (406) have been backwashed, the backwash drain electric valve (412) is closed, the outlet pipe electric valve (410) on the outlet pipe (409) is opened, and the inlet pipe electric valve (411) on the inlet pipe (403) is opened to start the next cycle of filtration.

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