Reduction recycling system and technology for semiconductor industry wastewater

Abstract

The invention relates to a decrement recycling system and process for semiconductor industry wastewater. A filter membrane for the semiconductor industry wastewater is prepared from the following raw materials in parts by weight: 15 to 20 parts of polyethersulfone, 2 to 3 parts of sulfonated polyetheretherketone, 10 to 12 parts of polyethylene glycol, 8 to 10 parts of polyvinylpyrrolidone, 4 to 10 parts of carboxyl betaine, 1 to 4 parts of PSS intercalation MgAl-LDH, 30 to 40 parts of solvent and 8 to 20 parts of cosolvent. The system comprises: a pretreatment subsystem, which is used for carrying out classification pretreatment on different types of semiconductor wastewater; and the recycling subsystem is used for carrying out advanced treatment on the pretreated wastewater to realize recycling. According to the semiconductor industry wastewater decrement recycling system, front and back matching is proper, colloid is not prone to accumulation in the UF membrane water purification unit, and the RO water purification unit is small in pressure and long in service life.

Description

TECHNICAL FIELD

[0001] The present application relates to wastewater treatment, more particularly, it relates to a filtration membrane, a semiconductor industry wastewater reduction and reuse system and process. BACKGROUND

[0002] In the semiconductor manufacturing process, a series of complex processes such as photolithography, etching, deposition, ion implantation, grinding and cleaning are required, which results in a large amount of industrial wastewater with extremely complex components. The wastewater not only contains high-concentration inorganic ions such as HF and heavy metal ions, but also contains biotoxic organic matter such as photoresist, organic solvent and surfactant, and colloidal particles such as silica sol and metal oxide colloid. The water quality of the wastewater fluctuates greatly, and the scaling caused by the synergistic effect between pollutants can quickly reduce the wastewater treatment flux, further challenging the wastewater reduction and reuse treatment.

[0003] In the treatment of semiconductor wastewater, hollow fiber polyether sulfone membrane is widely used in colloidal, heavy metal ion interception and nanoparticle separation process due to its organic solvent resistance, high mechanical strength and adjustable pore size distribution. The self-supporting structure of the inner cavity can greatly reduce the internal pressure loss.

[0004] However, the existing polyether sulfone membrane usually has a large water contact angle, and proteins and colloids are easy to adhere. Long-term use can easily cause blockage. After hydrophilic modification or addition of hydrophilic components, the membrane layer strength is reduced, resulting in pore structure collapse and long-term water treatment stability decline. The addition of reinforcing fillers causes poor interfacial compatibility, stress microcracks, and accelerated membrane aging. In the high-flux cross-flow water treatment process, the requirements for membrane material strength cannot be well met. Therefore, it is of great significance to provide a high-strength, high-flux, colloidal polyether sulfone membrane that is not easy to adhere, a semiconductor industry wastewater reduction and reuse system and process. SUMMARY

[0005] In order to solve the problems of low colloidal reuse rate and colloidal adhesion to the membrane material in semiconductor wastewater, the present application provides a semiconductor industry wastewater reduction and reuse system and process.

[0006] In the first aspect, the present application provides a filtration membrane for semiconductor industry wastewater treatment, which comprises the following mass parts of raw materials: polyether sulfone 15-20 parts, sulfonated polyether ether ketone 2-3 parts, polyethylene glycol 10-12 parts, polyvinylpyrrolidone 8-10 parts, carboxybetaine 4-10 parts, PSS intercalated MgAl-LDH 1-4 parts, solvent 30-40 parts, and cosolvent 8-20 parts.

[0007] By adopting the above scheme, the polyether sulfone is a high-performance aromatic polymer, has excellent mechanical strength and thermal stability, chemical resistance, and certain resistance to corrosion of acids, alkalis and organic solvents in semiconductor wastewater and temperature fluctuations, and the ether bond provides a certain flexibility to form a hydrophobic microzone support film structure. The sulfonated polyether ether ketone has high compatibility with the polyether sulfone. By adding a certain amount of sulfonated polyether ether ketone, sulfonic acid groups are introduced, which can not only improve the surface hydrophilicity of the membrane material and reduce the adsorption of organic pollutants such as photoresist and surfactants, but also introduce negatively charged sulfonic acid groups. The sulfonic acid group ionizes to form a hydration layer, and the electrostatic repulsion of anions inhibits phase separation. By adding a certain amount of polyvinylpyrrolidone and polyethylene glycol, porosity is increased, water flux is improved, pore size distribution is appropriate, and the filtration membrane also has a certain flexibility. By adding a certain amount of carboxybetaine, the quaternary ammonium cation and the sulfonic acid anion form an electrically neutral dipole, adsorb water molecules to form a dense hydration layer, and further improve the resistance effect of photoresist residues, surfactants and other pollutants in wastewater. By adding a certain amount of PSS intercalated MgAl-LDH, the LDH achieves better dispersion, compatibility and reinforcement effect on the membrane material, which is more suitable for cross-flow filtration. The LDH layer adsorbs heavy metal ions, the polystyrene sulfonate interlayer expands the interlayer spacing, improves the ion exchange capacity, and the sulfonic acid group further enhances the interface hydrophilicity. At the same time, the sulfonic acid group and the quaternary ammonium cation of the carboxybetaine through ion pair interaction enhance the interface bonding force, the sulfonic acid group ionizes to attract hydrated hydrogen ions, and the dipole hydration layer of the carboxybetaine is coupled. The prepared membrane material is not easy to adhere to colloids, has small fluid resistance, and is more suitable for cross-flow filtration.

[0008] In a second aspect, the application provides a preparation method of a filtration membrane for semiconductor industry wastewater treatment, characterized in that the preparation method comprises the following preparation steps: weighing raw materials according to mass parts, heating and stirring, and vacuum degassing to obtain a casting solution; extruding the casting solution from a spinneret, and sequentially entering an air bath and a coagulation bath to obtain the filtration membrane, wherein the coagulation bath comprises an ethanol aqueous solution and aziridine.

[0009] By adopting the above scheme, the carboxybetaine is interface-limited crosslinked with the aziridine after entering the coagulation bath, a more dense crosslinked shell layer is formed on the membrane surface, the hydration barrier is more stable, and the adsorption of proteins and colloids is significantly reduced.

[0010] In a specific embodiment, the PSS intercalated MgAl-LDH is an epoxy silane coupling agent modified PSS intercalated MgAl-LDH.

[0011] By taking the above scheme, the compatibility of MgAl-LDH with the matrix is further improved, and after modification by the epoxy silane coupling agent, not only the cohesion of the membrane material is further enhanced, but also a certain crosslinking is generated at the site of the PSS intercalated MgAl-LDH after the casting solution enters the coagulation bath to form an anchoring effect, and the surface of the membrane material is also smoother, the resistance of the semiconductor wastewater is smaller in the cross-flow filtration process, and the internal pressure loss and colloid adhesion are further reduced.

[0012] In a specific embodiment, the mass ratio of polyethylene glycol, polyvinylpyrrolidone and PSS intercalated MgAl-LDH is 11: (8-10): (2.5-3.5).

[0013] Preferably, the mass ratio of polyethylene glycol, polyvinylpyrrolidone and PSS intercalated MgAl-LDH is 11: (8-10): (2.5-3.5).

[0014] By taking the above scheme, PEG accelerates the solvent-nonsolvent exchange, promotes the penetration of the finger-like pores, polyvinylpyrrolidone delays the surface solidification, increases the density and crosslinking degree of the surface layer sponge pores, PSS intercalated MgAl-LDH as a heterogeneous nucleation point, induces the formation of micropores, and the prepared filtration membrane realizes a multi-level pore gradient, which is more suitable for the complex composition in semiconductor wastewater.

[0015] In a specific embodiment, the air bath height is 12-15 cm, the casting solution pressure is 0.3-0.4 MPa, and the coagulation bath temperature is 50-70℃.

[0016] By taking the above scheme, water molecules quickly penetrate, and PSBMA and PEG form a super-hydrophilic skin layer. At the same time, carboxybetaine migrates to the membrane surface to form a shell layer with strength and hydrophilicity, and the crosslinking effect is good.

[0017] In a specific embodiment, the mass ratio of epoxy silane coupling agent modified PSS intercalated MgAl-LDH and carboxybetaine is (2.5-3.5):8.

[0018] In a specific embodiment, aziridine includes 5.5-6.2 functionality aziridine.

[0019] Preferably, the mass ratio of epoxy silane coupling agent modified PSS intercalated MgAl-LDH and carboxybetaine is 3:8.

[0020] By adopting the above scheme, the cross-linking degree of aziridine with carboxybetaine and epoxy silane coupling agent modified PSS intercalated MgAl-LDH in the casting solution is appropriate, which can fully "anchor" the surface of the membrane material and the site where PSS intercalated MgAl-LDH is located, and will not excessively reduce the wastewater flux, and the prepared filtration membrane has higher flux and service life.

[0021] In a third aspect, the application discloses a semiconductor industry wastewater reduction and recycling system, comprising: a pretreatment subsystem for classifying and pretreating different types of semiconductor wastewater; and a recycling subsystem for deep treatment of the pretreated wastewater to realize recycling. The pretreatment subsystem comprises a grinding and cutting wastewater pretreatment module, a heavy metal wastewater pretreatment module and a fluorine-containing wastewater pretreatment module, and the recycling subsystem comprises an UF membrane water purification module and an RO membrane water purification module. The grinding and cutting wastewater pretreatment module is used for pretreating silicon-containing wastewater generated in the process of grinding and cutting silicon wafers. The heavy metal wastewater pretreatment module is used for pretreating heavy metal wastewater containing nickel and copper, and comprises, in sequence, a pH adjusting unit, a precipitation reaction unit, a flocculation unit, a precipitation unit, a sand filtration unit and a resin deep treatment unit. The fluorine-containing wastewater pretreatment module is used for pretreating fluorine-containing wastewater, and comprises, in sequence, a pH adjusting unit, a flocculation unit and an inclined plate precipitation unit. The recycling subsystem comprises an UF membrane water purification module and an RO membrane water purification module. The wastewater pretreated by different pretreatment modules is mixed and then enters the UF membrane water purification module, and then enters 1# adjusting tank, 2# adjusting tank and 3# adjusting tank in sequence. The UF membrane water purification module comprises a filtration module, and the filtration module comprises the filtration membrane.

[0022] By adopting the above scheme, the multi-stage treatment chain realizes removal of wastewater with different pollution concentrations, alleviates water quality fluctuation, realizes better guarantee of water inlet stability through three-stage adjusting tanks and turbidity feedback control, and significantly reduces the UF filtration membrane pollution risk. The resin deep treatment of the heavy metal wastewater can effectively alleviate the RO membrane poisoning.

[0023] Preferably, the UF membrane water purification module further comprises a pneumatic valve, a turbidity meter, a differential pressure sensor, a water inlet pump, a backwashing water pump and a control system; the RO membrane water purification module comprises a 1 μm safety filter, a high-pressure pump, an RO membrane group, a scale inhibitor dosing system, a control system and an on-site control panel, and corresponding instrument valves and other auxiliary systems.

[0024] In one specific embodiment, NaOH is added first to adjust the pH of the wastewater, and then Na2S is used to react with the nickel ions in the wastewater to generate a precipitate.

[0025] PAC and PAM are added to form flocculation in the conditioning tank, and then metal sulfides are precipitated in the sedimentation tank, suspended impurities in the wastewater are removed by sand filtration, and finally the wastewater is treated by resin for deep treatment, so that the nickel concentration in the wastewater reaches the semiconductor first-class pollutant discharge standard.

[0026] In one specific embodiment, the filter membrane group includes 25-30 filter membranes / sleeve membranes, 3 sets of UF membrane systems are connected in parallel, the membrane area is 70-75 m 2 , the membrane diameter is 200-240 mm, and the length is 1-2 meters.

[0027] In a fourth aspect, the application provides a reuse process of a semiconductor industry wastewater reduction and reuse system, characterized in that it comprises the following steps: The semiconductor wastewater is classified and pretreated by a plurality of pretreatment modules of a pretreatment subsystem, and then the wastewater is deeply treated by a recycling subsystem to realize recycling; wherein, The UF membrane water purification module is cross-flow filtration, the running time is 25-35 minutes, the positive flushing time is 50-60 seconds, the positive flushing flux is 50-120 LmH, then gas washing is performed, the gas washing flow is 8-12 nm 3 / min, and finally backwashing is performed, the backwashing flux is 200-300 LmH, and after running for 8-12 hours, chemical cleaning is performed, during chemical cleaning, soaking is performed for 5-15 minutes first, then each set is cleaned for 10-20 minutes, and then circulation is performed.

[0028] Preferably, the recovery rate is controlled at 55-65%.

[0029] By adopting the above scheme, cross-flow filtration, low-pressure positive flushing, high-intensity gas washing, and high-flux backwashing are sequentially performed, the flux is large, the cleaning effect is good, the mud cake layer on the membrane surface is physically stripped, the chemical cleaning frequency is reduced, the physical pollution difficulty of the traditional UF membrane is effectively solved, the system and the membrane material of the application are suitable for use, and the operation cost is reduced.

[0030] High flow rate generates strong turbulence, reduces boundary layer thickness, reduces the deposition of pollutants on the membrane surface, shear force forces the deposited particles to return to the fluid, delays pollution, high packing density increases the membrane area per unit volume, and meets the treatment capacity demand of semiconductor wastewater. The membrane material with good hydration effect in the application has good cooperation effect.

[0031] The fluorine-containing wastewater is preferably treated by an inclined plate sedimentation method, and the process flow comprises: fluorine-containing ion wastewater and calcium chloride are reacted, the pH value is controlled to be 10-11, an excess of slaked lime is added, calcium fluoride precipitate is produced through chemical reaction; the wastewater is added into a flocculation tank, aluminum sulfate and PAM are added, large flocculation is formed, the pH value is controlled to be 7-8, and the flocculation falls into an inclined plate sedimentation tank.

[0032] The nickel and copper-containing wastewater treatment process comprises: NaOH is added to adjust the pH value of the wastewater, Na2S is used to react with nickel ions in the wastewater to generate precipitate, PAC and PAM are added to form flocculation in the adjusting tank; then metal sulfide precipitate is generated in the sedimentation tank, suspended impurities in the wastewater are removed through sand filtration, and finally the wastewater is subjected to deep treatment through resin, so that the nickel concentration in the wastewater reaches the pollutant discharge standard.

[0033] Preferably, the UF membrane water purification module requires that the nickel content is less than 1 mg / L and the fluorine ion content is less than 10 mg / L.

[0034] Preferably, the RO membrane water purification module is two-stage treatment, and the arrangement ratio is (1-3):1, and the recovery rate is 45-55%.

[0035] Through the above scheme, the RO membrane is less prone to fouling.

[0036] Preferably, the RO membrane water purification module is connected with an ultrapure water preparation system downstream.

[0037] In summary, the application has the following beneficial effects: Compared with the prior art, the application provides a filtering membrane for semiconductor industry wastewater treatment, which adsorbs heavy metal ions through an LDH layer plate, expands the interlayer spacing through polystyrene sulfonate intercalation, improves the ion exchange capacity, and further enhances the interface hydrophilicity through sulfonic acid groups. At the same time, the sulfonic acid groups of sulfonated polyether ether ketone and the quaternary ammonium cation of carboxybetaine are coupled through ion pair interaction to enhance the interface bonding force, and the sulfonic acid groups ionize to attract hydrated hydrogen ions, which are coupled with the dipole hydration layer of carboxybetaine. The prepared membrane material is not easy to adhere to colloid, has small fluid resistance, and is more suitable for cross-flow filtration.

[0038] Compared with the prior art, the application provides a preparation method of a filtering membrane for semiconductor industry wastewater treatment, which modifies PSS intercalated in MgAl-LDH with carboxybetaine and epoxy silane coupling agent, and then interfaces with aziridine to form a more dense cross-linked shell on the membrane surface after entering the coagulation bath, so that the hydration barrier is more stable, the membrane pore anchoring on the membrane surface is enhanced, and the adsorption of protein and colloid is significantly reduced.

[0039] Compared with the prior art, the semiconductor industry wastewater reduction and recycling system and process provided by the application can generate strong turbulence at a high flow rate in the filtration process, reduce the thickness of the boundary layer, reduce the deposition of pollutants on the membrane surface, force the deposited particles to return to the fluid by shear force, delay the pollution and blockage, increase the unit volume membrane area by high packing density, and adapt to the large processing capacity requirement of semiconductor wastewater. BRIEF DESCRIPTION OF DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative effort.

[0041] Figure 1 A process flow diagram of the semiconductor industry wastewater reduction and recycling system provided by the application. DETAILED DESCRIPTION

[0042] In order to further help understand the technical solutions of the application, the technical solutions of the application are described in more detail by providing several specific embodiments. All the described embodiments are only some embodiments of the application, not all; the embodiments can be combined with each other, and the same or similar concepts or processes can not be described in some embodiments. The following embodiments are further illustrations of the application, and the application is not limited thereto.

[0043] The components used in the preparation examples in the embodiments of the application are all components obtained by the preparation examples. The remaining experimental reagents, unless otherwise specified, are all conventional commercially available brands or obtained by conventional preparation processes.

[0044] MgAl-LDH was purchased from Xi'an Qiyue Biological Technology Co., Ltd. Q-0326827; polystyrene sulfonic acid PSS was purchased from Yuan Ye Y33129; polyether sulfone was purchased from Merck Life Science GF98159787; sulfonated polyether ether ketone was purchased from Xi'an Qiyue Biological Technology Co., Ltd., with a sulfonation degree of 10%; polyethylene glycol was purchased from Renda Chemical PEG-3000; polyvinylpyrrolidone was purchased from Huzhou Shenhua, with a density of 1.69 g / cm³; trifunctional aziridine was purchased from Haodeng Material HD-100; hexafunctional aziridine was purchased from HUITUCHEM Huituo HT-160; carboxybetaine, i.e. trimethylglycine, was purchased from Yuan Ye S48731.

[0045] Preparation Example

[0046] Preparation Example 1: PSS intercalated MgAl-LDH PSS intercalated MgAl-LDH prepared in Preparation Example 1 was added into 150 ml of 30 wt% ethanol aqueous solution, 2 g of KH-550 was added, and the mixture was heated at 70°C for 1 h. The product was filtered, washed, and dried to obtain PSS intercalated MgAl-LDH modified by amino silane coupling agent.

[0047] Preparation Example 2: PSS intercalated MgAl-LDH modified by epoxy silane coupling agent PSS intercalated MgAl-LDH prepared in Preparation Example 1 was added into 150 ml of 30 wt% ethanol aqueous solution, 2 g of KH-550 was added, and the mixture was heated at 70°C for 1 h. The product was filtered, washed, and dried to obtain PSS intercalated MgAl-LDH modified by amino silane coupling agent.

[0048] Preparation Example 3: PSS intercalated MgAl-LDH modified by amino silane coupling agent PSS intercalated MgAl-LDH prepared in Preparation Example 1 was added into 150 ml of 30 wt% ethanol aqueous solution, 2 g of KH-550 was added, and the mixture was heated at 70°C for 1 h. The product was filtered, washed, and dried to obtain PSS intercalated MgAl-LDH modified by amino silane coupling agent. Example Example 1

[0049] Preparation of casting solution: polyether sulfone 18 g, sulfonated polyether ether ketone 2 g, polyethylene glycol 10 g, polyvinylpyrrolidone 10 g, carboxybetaine 6 g, PSS intercalated MgAl-LDH prepared in Preparation Example 1 3 g, 1,4-butyrolactone 30 g, ε-caprolactam 10 g, dimethylacetamide 10 g.

[0050] Preparation process: 1,4-butyrolactone, ε-caprolactam, and dimethylacetamide were mixed and stirred at 40°C for 1 h. Polyether sulfone, sulfonated polyether ether ketone, and polyvinylpyrrolidone were added, and the mixture was stirred at 95°C for 2 h. The remaining components were added, and the mixture was stirred at 70°C for 3 h. Vacuum degassing was performed at 40°C for 12 h. The casting solution was extruded from a spinneret with a 5 μm filter core, and then passed through an air bath and a coagulation bath in sequence. The inner diameter / outer diameter of the spinneret was 0.8 / 1.4 mm, the core liquid flow rate was 3.0 g / min, the casting solution pressure was 0.35 MPa, the air bath height was 12 cm, and the coagulation bath temperature was 50°C. The coagulation bath included 10 wt% ethanol, 85 wt% water, and 5 wt% trifunctional aziridine. Example 2

[0051] Preparation process: 1,4-butyrolactone, ε-caprolactam, dimethylacetamide were mixed, stirred at 40℃ for 1h, polyether sulfone, sulfonated polyether ether ketone, polyvinylpyrrolidone were added, heated to 95℃ and stirred for 2h, cooled to 70℃, the remaining components were added, and stirred for 3h, vacuum degassing at 40℃ for 12h, filtration, the casting solution was extruded from the spinneret with a filter core of 5μm, into air bath and coagulation bath in turn, the inner diameter / outer diameter of the spinneret was 0.8 / 1.4mm, the core liquid flow rate was 3.0g / min, the casting solution pressure was 0.35MPa, the air bath height was 12cm, the coagulation bath temperature was 50℃, and the coagulation bath included 10wt% ethanol, 85wt% water and 5wt% trifunctional aziridine.

[0052] Preparation process: 1,4-butyrolactone, ε-caprolactam, dimethylacetamide were mixed, stirred at 40℃ for 1h, polyether sulfone, sulfonated polyether ether ketone, polyvinylpyrrolidone were added, heated to 95℃ and stirred for 2h, cooled to 70℃, the remaining components were added, and stirred for 3h, vacuum degassing at 40℃ for 12h, filtration, the casting solution was extruded from the spinneret with a filter core of 5μm, into air bath and coagulation bath in turn, the inner diameter / outer diameter of the spinneret was 0.8 / 1.4mm, the core liquid flow rate was 3.0g / min, the casting solution pressure was 0.35MPa, the air bath height was 12cm, the coagulation bath temperature was 50℃, and the coagulation bath included 10wt% ethanol, 85wt% water and 5wt% trifunctional aziridine. Example 3

[0053] Preparation process: 1,4-butyrolactone, ε-caprolactam, dimethylacetamide were mixed, stirred at 40℃ for 1h, polyether sulfone, sulfonated polyether ether ketone, polyvinylpyrrolidone were added, heated to 95℃ and stirred for 2h, cooled to 70℃, the remaining components were added, and stirred for 3h, vacuum degassing at 40℃ for 12h, filtration, the casting solution was extruded from the spinneret with a filter core of 5μm, into air bath and coagulation bath in turn, the inner diameter / outer diameter of the spinneret was 0.8 / 1.4mm, the core liquid flow rate was 3.0g / min, the casting solution pressure was 0.35MPa, the air bath height was 12cm, the coagulation bath temperature was 50℃, and the coagulation bath included 10wt% ethanol, 85wt% water and 5wt% trifunctional aziridine.

[0054] Preparation process: 1,4-butyrolactone, ε-caprolactam, dimethylacetamide were mixed, stirred at 40℃ for 1h, polyether sulfone, sulfonated polyether ether ketone, polyvinylpyrrolidone were added, heated to 95℃ and stirred for 2h, cooled to 70℃, the remaining components were added, and stirred for 3h, vacuum degassing at 40℃ for 12h, filtration, the casting solution was extruded from the spinneret with a filter core of 5μm, into air bath and coagulation bath in turn, the inner diameter / outer diameter of the spinneret was 0.8 / 1.4mm, the core liquid flow rate was 3.0g / min, the casting solution pressure was 0.35MPa, the air bath height was 12cm, the coagulation bath temperature was 50℃, and the coagulation bath included 10wt% ethanol, 85wt% water and 5wt% trifunctional aziridine. Example 4

[0055] Preparation process: 1,4-butyrolactone, ε-caprolactam, dimethylacetamide were mixed, stirred at 40℃ for 1h, polyether sulfone, sulfonated polyether ether ketone, polyvinylpyrrolidone were added, heated to 95℃ and stirred for 2h, cooled to 70℃, the remaining components were added, and stirred for 3h, vacuum degassing at 40℃ for 12h, filtration, the casting solution was extruded from the spinneret with a filter core of 5μm, into air bath and coagulation bath in turn, the inner diameter / outer diameter of the spinneret was 0.8 / 1.4mm, the core liquid flow rate was 3.0g / min, the casting solution pressure was 0.35MPa, the air bath height was 12cm, the coagulation bath temperature was 50℃, and the coagulation bath included 10wt% ethanol, 85wt% water and 5wt% trifunctional aziridine.

[0056] Preparation process: 1,4-butyrolactone, ε-caprolactam, dimethylacetamide were mixed, stirred at 40℃ for 1h, polyether sulfone, sulfonated polyether ether ketone, polyvinylpyrrolidone were added, heated to 95℃ and stirred for 2h, cooled to 70℃, the remaining components were added, and stirring was continued for 3h, vacuum degassing at 40℃ for 12h, filtration, the casting solution was extruded from the spinneret with a 5μm filter core, into the air bath and coagulation bath in turn, the inner diameter / outer diameter of the spinneret was 0.8 / 1.4mm, the core liquid flow rate was 3.0g / min, the casting solution pressure was 0.35MPa, the air bath height was 12cm, the coagulation bath temperature was 50℃, and the coagulation bath included 10wt% ethanol, 85wt% water and 5wt% trifunctional aziridine. Example 5

[0057] Preparation of casting solution raw materials: polyether sulfone 18g, sulfonated polyether ether ketone 2g, polyethylene glycol 10g, polyvinylpyrrolidone 10g, carboxy betaine 6g, PSS intercalated MgAl-LDH modified by epoxy silane coupling agent prepared in Preparation Example 2 4g, 1,4-butyrolactone 30g, ε-caprolactam 10g, dimethylacetamide 10g.

[0058] Preparation process: 1,4-butyrolactone, ε-caprolactam, dimethylacetamide were mixed, stirred at 40℃ for 1h, polyether sulfone, sulfonated polyether ether ketone, polyvinylpyrrolidone were added, heated to 95℃ and stirred for 2h, cooled to 70℃, the remaining components were added, and stirring was continued for 3h, vacuum degassing at 40℃ for 12h, filtration, the casting solution was extruded from the spinneret with a 5μm filter core, into the air bath and coagulation bath in turn, the inner diameter / outer diameter of the spinneret was 0.8 / 1.4mm, the core liquid flow rate was 3.0g / min, the casting solution pressure was 0.35MPa, the air bath height was 12cm, the coagulation bath temperature was 50℃, and the coagulation bath included 10wt% ethanol, 85wt% water and 5wt% trifunctional aziridine. Example 6

[0059] Preparation of casting solution raw materials: polyether sulfone 18g, sulfonated polyether ether ketone 2g, polyethylene glycol 11g, polyvinylpyrrolidone 10g, carboxy betaine 8g, PSS intercalated MgAl-LDH modified by epoxy silane coupling agent prepared in Preparation Example 2 3g, 1,4-butyrolactone 30g, ε-caprolactam 10g, dimethylacetamide 10g.

[0060] Preparation process: 1,4-butyrolactone, ε-caprolactam, dimethylacetamide were mixed, stirred at 40℃ for 1h, polyether sulfone, sulfonated polyether ether ketone, polyvinylpyrrolidone were added, heated to 95℃ and stirred for 2h, cooled to 70℃, the remaining components were added, and stirring was continued for 3h, vacuum degassing at 40℃ for 12h, filtration, the casting solution was extruded from the spinneret with a filter core of 5μm, into air bath and coagulation bath in turn, the inner diameter / outer diameter of the spinneret was 0.8 / 1.4mm, the core liquid flow rate was 3.0g / min, the casting solution pressure was 0.35MPa, the air bath height was 12cm, the coagulation bath temperature was 50℃, and the coagulation bath included 10wt% ethanol, 85wt% water and 5wt% trifunctional aziridine. Example 7

[0061] Preparation of casting solution raw materials: polyether sulfone 18g, sulfonated polyether ether ketone 2g, polyethylene glycol 10g, polyvinylpyrrolidone 10g, carboxy betaine 6g, amino modified PSS intercalated MgAl-LDH prepared in Preparation Example 3 3g, 1,4-butyrolactone 30g, ε-caprolactam 10g, dimethylacetamide 10g.

[0062] Preparation process: 1,4-butyrolactone, ε-caprolactam, dimethylacetamide were mixed, stirred at 40℃ for 1h, polyether sulfone, sulfonated polyether ether ketone, polyvinylpyrrolidone were added, heated to 95℃ and stirred for 2h, cooled to 70℃, the remaining components were added, and stirring was continued for 3h, vacuum degassing at 40℃ for 12h, filtration, the casting solution was extruded from the spinneret with a filter core of 5μm, into air bath and coagulation bath in turn, the inner diameter / outer diameter of the spinneret was 0.8 / 1.4mm, the core liquid flow rate was 3.0g / min, the casting solution pressure was 0.35MPa, the air bath height was 10cm, the coagulation bath temperature was 50℃, and the coagulation bath included 10wt% ethanol, 85wt% water and 5wt% trifunctional aziridine. Example 8

[0063] Preparation of casting solution raw materials: polyether sulfone 18g, sulfonated polyether ether ketone 2g, polyethylene glycol 11g, polyvinylpyrrolidone 10g, carboxy betaine 8g, epoxy modified PSS intercalated MgAl-LDH prepared in Preparation Example 2 3g, 1,4-butyrolactone 30g, ε-caprolactam 10g, dimethylacetamide 10g.

[0064] Preparation process: 1,4-butyrolactone, ε-caprolactam, dimethylacetamide were mixed, stirred at 40℃ for 1h, polyether sulfone, sulfonated polyether ether ketone, polyvinylpyrrolidone were added, heated to 95℃ and stirred for 2h, cooled to 70℃, the remaining components were added, and stirred for 3h, vacuum degassing at 40℃ for 12h, filtration, the casting solution was extruded from the spinneret with a 5μm filter core, into the air bath and coagulation bath in turn, the inner diameter / outer diameter of the spinneret was 0.8 / 1.4mm, the core liquid flow rate was 3.0g / min, the casting solution pressure was 0.35MPa, the air bath height was 12cm, the coagulation bath temperature was 50℃, and the coagulation bath included 10wt% ethanol, 85wt% water and 5wt% hexafunctional aziridine. Example 9

[0065] Preparation of casting solution raw materials: polyether sulfone 18g, sulfonated polyether ether ketone 2g, polyethylene glycol 10g, polyvinylpyrrolidone 10g, carboxybetaine 6g, PSS intercalated MgAl-LDH 3g, 1,4-butyrolactone 30g, ε-caprolactam 10g, dimethylacetamide 10g.

[0066] Preparation process: 1,4-butyrolactone, ε-caprolactam, dimethylacetamide were mixed, stirred at 40℃ for 1h, polyether sulfone, sulfonated polyether ether ketone, polyvinylpyrrolidone were added, heated to 95℃ and stirred for 2h, cooled to 70℃, the remaining components were added, and stirred for 3h, vacuum degassing at 40℃ for 12h, filtration, the casting solution was extruded from the spinneret with a 5μm filter core, into the air bath and coagulation bath in turn, the inner diameter / outer diameter of the spinneret was 0.8 / 1.4mm, the core liquid flow rate was 3.0g / min, the casting solution pressure was 0.35MPa, the air bath height was 12cm, the coagulation bath temperature was 50℃, and the coagulation bath included 10wt% ethanol, 90wt% water. Example 10

[0067] Reuse process: A plurality of pretreatment modules are used for classified pretreatment of different types of semiconductor wastewater: The grinding and cutting wastewater pretreatment module is used for pretreatment of silicon-containing wastewater generated by grinding and cutting silicon wafers: the pH is adjusted to 7, PAC is added to 20mg / L, and PAM is added to 1mg / L, and after 2 hours of sedimentation, 50-100μm quartz sand filtration and 5-10μm activated carbon filtration are performed; The pH is controlled at neutral to fully release silicon, PAC is added to destabilize the silicon colloid through electrical neutralization, PAM is further bridged to form large flocs, PAC is destabilized through electrical neutralization, and PAM is further bridged to form large flocs for sufficient filtration.

[0068] The heavy metal wastewater pretreatment module is used for pretreating heavy metal wastewater containing nickel and copper, and sequentially comprises a pH adjusting unit, a precipitation reaction unit, a flocculation unit, a precipitation unit, a sand filtration unit and a resin deep treatment unit. The pH is adjusted to 9 by NaOH and Ca(OH)2 in a mass ratio of 1:1 to generate a heterogeneous co-precipitation, and the reaction is ensured for 15-30 minutes to ensure that the metal ions fully react with OH⁻ for 30 minutes, and then the metal ions are precipitated after the complex is broken. PAC 30 mg / L and PAM 2 mg / L are added for flocculation, and then 200 rpm stirring is performed for 1 minute, and then 100 rpm stirring is performed for 10 minutes. The surface load of the precipitation unit is 1 m³ / (m²·h) to fully precipitate the heavy metal hydroxide, and the sludge reflux ratio is 15% to improve the precipitation efficiency. The particle size of the quartz sand is 0.5-1.2 mm, the filtration speed is 5 m / h, and backwashing is performed according to the turbidity of the influent. The resin is a heavy metal chelating resin, and the working flow rate is 12 BV / h, so that the heavy metal concentration is reduced to the μg / L level, and the subsequent UF / RO membrane influent requirements are met; The fluorine-containing wastewater pretreatment module is used for pretreating fluorine-containing wastewater, and sequentially comprises a pH adjusting unit, a flocculation unit and an inclined plate sedimentation tank. The pH is adjusted to 7 to make Al³⁺ fully hydrolyze to generate a colloid. PAC is added to 350 mg / L, and the colloid is generated after flocculation for 20 minutes. The inclined plate load is 4 m³ / (m²·h), and the angle is 60° to make the sludge better slide, and the concentration is 7 mg / L; After the wastewater treated by different pretreatment modules is mixed, the wastewater enters the UF membrane water purification unit, and sequentially enters a 1# adjusting tank, a 2# adjusting tank and a 3# adjusting tank. The turbidity of each adjusting tank is monitored by a turbidity instrument. If the turbidity of the 1# adjusting tank is qualified, the wastewater sequentially enters the 2# adjusting tank and the 3# adjusting tank. If the turbidity is not qualified, the wastewater is backflowed to the 1# adjusting tank for reprocessing. The membrane group in the adjusting tank is used, and the running time of each membrane group is 30 minutes, the forward flushing is performed, the forward flushing time is 60 seconds, the forward flushing flux is calculated according to 60 Lmh, the forward flushing water volume is 60(lmh)x55(m 2 )x28(branches) / 1000=92m 3 / hr, and then air washing is performed. The air washing flow is calculated according to 10 nm 3 / min, and the total air washing volume is 10(nm 3 / min)x28(branches)x1 set=280nm 3 / min; then backwashing is performed. The backwashing flow is calculated according to 250(Lmh)x55(m 2 )x28(branches)=385m 3 / hr, and chemical cleaning is performed after 10 hours of operation. During the chemical cleaning, chemical reagents NaOH and NaCLO 1-2 mg / L are sequentially added, the membrane group is soaked for 10 minutes, and then each set of membrane group is cleaned for 15 minutes. Then the wastewater is circulated and operated. If the turbidity exceeds 5 NTU, the wastewater is backflowed.

[0069] Then into the RO membrane water purification unit, by high pressure water pump into the RO membrane system, water pressure 0.3 MPa, water production pressure 2.0 MPa, according to the water quality characteristics of this time into the selection of anti-pollution brackish water RO membrane, reverse osmosis RO membrane main role is to carry on the desalination treatment to the pretreated production water, RO membrane assembly recovery rate of 50%, designed as two-stage treatment, the arrangement ratio is 2:1 section, the first section 2 membrane, the second section 1 membrane; as raw water into the pure water system of pretreatment water system, the remaining half of the high conductivity water production, as cooling tower water or flushing ground and toilet water, make full use of to achieve the purpose of energy saving, this RO membrane system is wastewater recycling water reverse osmosis application, the system includes 1 μm security filter, high pressure pump, RO membrane group, scale inhibitor dosing system and control system and on-site control panel, and the corresponding instrument valve. Comparative Example

[0070] Comparative Example 1 Casting solution raw material preparation: polyether sulfone 18 g, sulfonated polyether ether ketone 2 g, polyethylene glycol 10 g, polyvinylpyrrolidone 10 g, carboxy betaine 6 g, 1,4-butyrolactone 30 g, ε-caprolactam 10 g, dimethylacetamide 10 g.

[0071] Preparation process: mix 1,4-butyrolactone, ε-caprolactam, dimethylacetamide, stir at 40°C for 1 h, add polyether sulfone, sulfonated polyether ether ketone, polyvinylpyrrolidone, heat to 95°C and stir for 2 h, cool to 70°C, add the remaining components, continue to stir for 3 h, vacuum degassing at 40°C for 12 h, filter, extrude the casting solution from the spinneret with a 5 μm filter core, into an air bath and a coagulation bath in turn, the inner diameter / outer diameter of the spinneret = 0.8 / 1.4 mm, the core liquid flow rate is 3.0 g / min, the casting solution pressure is 0.35 MPa, the air bath height is 12 cm, and the coagulation bath temperature is 50°C. The coagulation bath comprises 10 wt% ethanol, 85 wt% water and 5 wt% trifunctional aziridine.

[0072] Comparative Example 2 Casting solution raw material preparation: polyether sulfone 18 g, sulfonated polyether ether ketone 2 g, polyethylene glycol 10 g, polyvinylpyrrolidone 10 g, PSS intercalated MgAl-LDH 3 g, 1,4-butyrolactone 30 g, ε-caprolactam 10 g, dimethylacetamide 10 g.

[0073] Preparation process: 1,4-butyrolactone, epsilon-caprolactam, dimethylacetamide were mixed, stirred at 40℃ for 1h, polyether sulfone, sulfonated polyether ether ketone, polyvinylpyrrolidone were added, the temperature was raised to 95℃ and stirred for 2h, the temperature was lowered to 70℃, the remaining components were added, and stirring was continued for 3h, vacuum degassing at 40℃ for 12h, filtration, the casting solution was extruded from the spinneret with a filter core of 5μm, and then entered the air bath and the coagulation bath in turn, the inner diameter / outer diameter of the spinneret was 0.8 / 1.4mm, the core liquid flow rate was 3.0g / min, the casting solution pressure was 0.35MPa, the air bath height was 12cm, and the coagulation bath temperature was 50℃, and the coagulation bath included 10wt% ethanol, 85wt% water and 5wt% trifunctional aziridine. Performance detection experiment

[0074] The prepared sample was used for semiconductor wastewater treatment in the above UF recovery unit, and flux test and colloidal pollution rate test were carried out after stable operation for 2 hours under a pressure of 0.15MPa.

[0075] The flux test calculation method is as follows: P=V / (Axt), wherein P is the permeation flux of the membrane (L / (m 2 ·h)), V is the volume of the collected permeate liquid (L), A is the membrane area (m 2 ), and t is the permeate liquid time (h).

[0076] The colloidal pollution rate test calculation method is as follows: the pressure difference on both sides of the UF filtration membrane after running for 2 hours is measured, and the colloidal pollution rate (bar / h) is obtained by dividing the change amount of the pressure difference by the time interval, and the results are recorded in Table 1.

[0077] Table 1 Flux (LmH) Gelatin contamination rate (bar / h) Example 1 140.1 0.22 Example 2 147.3 0.16 Example 3 145.7 0.23 Example 4 149.7 0.12 Example 5 146.0 0.18 Example 6 151.8 0.11 Example 7 142.4 0.20 Example 8 152.7 0.07 Example 9 127.4 0.31 Comparative Example 1 110.8 0.48 Comparative Example 2 107.6 0.44 In combination with Examples 1-3, 7, 9, Comparative Examples 1-2 and in combination with Table 1, the present application modifies PSS intercalated MgAl-LDH by adding a certain mass of carboxybetaine and epoxy silane coupling agent in the casting solution, adds a certain mass of aziridine in the coagulation bath and limits a certain preparation process, and the prepared filtration membrane has high flux and service life, and colloids are not easy to deposit, which is suitable for semiconductor wastewater treatment.

[0078] In combination with Examples 2, 4-6 and in combination with Table 1, the present application limits the mass ratio of polyethylene glycol, polyvinylpyrrolidone and PSS intercalated MgAl-LDH, carboxybetaine, so that the membrane filament is better shaped, the hydration barrier is more stable, and the performance is better.

[0079] In combination with Examples 4, 8 and in combination with Table 1, the present application further reduces the colloidal pollution rate by limiting the functionality of aziridine.

[0080] The embodiments of the present application are merely used for explaining the present application, and are not used for limiting the present application, and the person skilled in the art can make the modification to the embodiments without the creative contribution according to the needs after reading the present specification, and as long as the modification is within the scope of the present application, it is protected by the patent law.

Claims

1. A filtration membrane for semiconductor industry wastewater treatment, characterized by, The preparation method comprises the following steps: weighing raw materials, heating and stirring, and vacuum defoaming to prepare a casting solution, extruding the casting solution from a spinneret, and sequentially entering an air bath and a coagulation bath to obtain a product.

2. A method for preparing a filtration membrane for semiconductor industry wastewater treatment according to claim 1, characterized by: The preparation method comprises the following steps: weighing raw materials, heating and stirring, and vacuum defoaming to prepare a casting solution, extruding the casting solution from a spinneret, and sequentially entering an air bath and a coagulation bath to obtain a product. The mass ratio of polyethylene glycol, polyvinylpyrrolidone and PSS intercalated MgAl-LDH is 11: (8-10): (2.5-3.5). The air bath height is 12-15 cm, the casting solution pressure is 0.3-0.4 MPa, and the coagulation bath temperature is 50-70 DEG C. The coagulation bath comprises an ethanol aqueous solution and aziridine.

3. The method for preparing a filtration membrane for semiconductor industry wastewater treatment according to claim 2, characterized by: The mass ratio of the PSS intercalated MgAl-LDH modified by an epoxy silane coupling agent and the carboxybetaine is (2.5-3.5):

8.

4. The method for preparing a filtration membrane for semiconductor industry wastewater treatment according to claim 2, characterized by: The aziridine comprises 5.5-6.2 functionality aziridines.

5. A system for reducing and reusing semiconductor industry wastewater, characterized by: Preprocessing subsystem for classifying and preprocessing different types of semiconductor wastewater; Recycling subsystem for deep processing of the pretreated wastewater to realize recycling; The preprocessing subsystem comprises a grinding and cutting wastewater preprocessing module, a heavy metal wastewater preprocessing module and a fluorine-containing wastewater preprocessing module; The grinding and cutting wastewater preprocessing module is used for preprocessing silicon-containing wastewater generated in the grinding and cutting of silicon wafers; The heavy metal wastewater preprocessing module is used for preprocessing heavy metal wastewater containing nickel and copper, and comprises, in sequence, a pH adjusting unit, a precipitation reaction unit, a flocculation unit, a precipitation unit, a sand filtration unit and a resin deep processing unit; The fluorine-containing wastewater preprocessing module is used for preprocessing fluorine-containing wastewater, and comprises, in sequence, a pH adjusting unit, a flocculation unit and an inclined plate precipitation unit. The recycling subsystem comprises a UF membrane water purification module and an RO membrane water purification module; The UF membrane water purification module comprises a filtration module, and the filtration module comprises the filtration membrane according to claim 1. The UF membrane water purification module further comprises a pneumatic valve, a turbidimeter, a differential pressure sensor, a water inlet pump, a backwashing water pump and a control system; the RO membrane water purification module comprises a 1 mu m security filter, a high-pressure pump, an RO membrane group, a scale inhibitor dosing system, a control system and an on-site control panel, and corresponding instrument valves and other auxiliary systems.

6. The semiconductor industry wastewater minimization and reuse system of claim 5, wherein: The water inlet requirement of the UF membrane water purification module is that the nickel content is less than 1 mg / L and the fluorine ion content is less than 10 mg / L.

7. The semiconductor industry wastewater minimization and reuse system of claim 5, wherein: The filter membrane group includes 25-30 filter membranes / sleeve membranes, 3 sets of UF membrane systems are connected in parallel, the membrane area is 70-75 m 2 , the membrane diameter is 200-240 mm, and the length is 1-2 meters.

8. A reuse process using the semiconductor industry wastewater reduction and reuse system according to any one of claims 5 to 7, characterized by, It comprises the following steps: classified pretreatment of semiconductor wastewater by multiple pretreatment modules of a pretreatment subsystem; and deep treatment of the wastewater by a recycling subsystem to realize recycling; wherein the UF membrane water purification module is a cross-flow filtration, the operation time is 25-35 minutes, the positive flushing time is 50-60 seconds, the positive flushing flux is 50-120 LmH, then air washing is performed, the air washing flow is 8-12 nm / min, finally backwashing is performed, the backwashing flux is 200-300 LmH, after 8-12 hours of operation, chemical cleaning is performed, during the chemical cleaning, first soaking is performed for 5-15 minutes, then each set is cleaned for 10-20 minutes, and then circulation operation is performed again. 3 / min, finally backwashing is performed, the backwashing flux is 200-300 LmH, after 8-12 hours of operation, chemical cleaning is performed, during the chemical cleaning, first soaking is performed for 5-15 minutes, then each set is cleaned for 10-20 minutes, and then circulation operation is performed again.

9. The reuse process of claim 8, wherein: The RO membrane water purification module is two-stage treatment, and the arrangement ratio is (1-3): 1, and the recovery rate is 45-55%.

10. The reuse process of claim 8, wherein: ​

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