System for preparing electronic-grade source water from reclaimed water

Abstract

The utility model provides a system for preparing electronic-grade source water from reclaimed water, which relates to the technical field of preparation of electronic-grade source water from reclaimed water, and comprises pretreatment equipment, hollow fiber nanofiltration equipment, reverse osmosis equipment, photocatalytic oxidation equipment and ion exchange adsorption equipment which are connected in sequence, the hollow fiber nanofiltration equipment comprises a hollow fiber nanofiltration membrane, and the reverse osmosis equipment comprises a reverse osmosis membrane element; the problems of poor organic matter removal effect and low treatment efficiency of a reclaimed water treatment technology in the prior art are solved.

Description

Technical Field

[0001] This utility model belongs to the field of technology for preparing electronic-grade water from reclaimed water, and more specifically, relates to a system for preparing electronic-grade water from reclaimed water. Background Technology

[0002] With the rapid development of self-sufficiency in my country's semiconductor chip and display panel industries, the demand for electronic-grade water has increased significantly, and the source water for these industries is primarily tap water. Driven by national environmental protection policies and emission standards, replacing traditional water sources with reclaimed water to solve the "water security" dilemma of my country's high-end chip and semiconductor industries has become a future development direction. However, most existing reclaimed water is used for applications with low water quality requirements, such as urban greening and river landscape replenishment. For electronic-grade water, which has extremely stringent water quality requirements, reclaimed water cannot be directly reused in the preparation of electronic-grade ultrapure water. The main reason is that reclaimed water has a complex composition and is rich in urea and trihalomethanes, which easily penetrate the ultrapure water preparation system, leading to substandard ultrapure water quality and affecting product yield. Therefore, how to utilize reclaimed water to prepare electronic-grade source water has become the key to solving the above problems.

[0003] Existing reclaimed water treatment technologies suffer from the following drawbacks: simple oxidation treatment has limited effectiveness in removing organic matter; and physical adsorption and chemical oxidation methods result in low treatment efficiency. Compared to existing water sources, reclaimed water has a high concentration of organic matter, with the content of small-molecule organic matter such as urea reaching up to three times that of tap water. Furthermore, reverse osmosis treatment has a low rejection rate for specific small organic molecules, and its permeate still contains electrically neutral small-molecule organic matter such as halogenated hydrocarbons, oxygen-containing compounds, and nitrogen-containing compounds. Therefore, it is necessary to develop a technology for preparing electronic-grade source water from reclaimed water that offers superior treatment effects, high efficiency, and strong adaptability, based on the characteristics of reclaimed water quality. Utility Model Content

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a system for preparing electronic-grade water from reclaimed water, thus solving the problems of poor organic matter removal and low treatment efficiency in existing reclaimed water treatment technologies.

[0005] To achieve the above objectives, this utility model provides a system for preparing electronic-grade water source from reclaimed water, comprising:

[0006] The equipment comprises a pretreatment device, a hollow fiber nanofiltration device, a reverse osmosis device, a photocatalytic oxidation device, and an ion exchange adsorption device connected in sequence. The pretreatment device includes a filter, the hollow fiber nanofiltration device includes a hollow fiber nanofiltration membrane, and the reverse osmosis device includes a reverse osmosis membrane element.

[0007] Optionally, the filtration accuracy of the filter is 0.45um-50um.

[0008] Optionally, the hollow fiber nanofiltration membrane has a molecular weight cutoff range of 250 Da to 8000 Da.

[0009] Optionally, the reverse osmosis membrane element is a reverse osmosis membrane element used to remove neutral molecules.

[0010] Optionally, the photocatalytic oxidation device is an ultraviolet photocatalytic oxidation device.

[0011] Optionally, the ion exchange adsorption device is provided with ion exchange resin.

[0012] Optionally, the oxidant in the photocatalytic oxidation device is hydrogen peroxide, persulfate, or active chlorine, and the dosage of the oxidant is 5–100 mg / L.

[0013] Optionally, the ion exchange resin in the ion exchange adsorption device is a polystyrene-based gel-type weakly basic anion exchange resin, a polystyrene-based gel-type strongly basic anion exchange resin, a polystyrene-based macroporous weakly basic anion exchange resin, or a polystyrene-based macroporous strongly basic anion exchange resin.

[0014] This invention provides a system for preparing electronic-grade water from reclaimed water. Its advantages are as follows: the system comprises, from front to back, a pretreatment device with a filter, a hollow fiber nanofiltration device with a hollow fiber nanofiltration membrane, a reverse osmosis device with a reverse osmosis membrane assembly, a photocatalytic oxidation device for photocatalytic oxidation treatment, and an ion exchange adsorption device for ion adsorption treatment. This system efficiently removes organic matter from the reclaimed water, ensuring that the ultrapure water quality at the process end meets standards. By replacing traditional water sources with reclaimed water, it alleviates the contradiction between water scarcity and the increasing demand for electronic-grade ultrapure water in my country, promotes the industrial recycling of wastewater, and achieves high-quality and efficient regeneration. The transformation from water to electronic-grade source water: Reclaimed water is filtered through pretreatment equipment to remove particulate impurities and suspended solids, preventing physical damage to subsequent treatment equipment. Hollow fiber nanofiltration membranes are used to remove some organic matter after pretreatment, reducing the load on reverse osmosis treatment and retaining some divalent salts, thus mitigating the tendency of the concentrate to scale during reverse osmosis treatment. The reverse osmosis membrane module removes a large amount of small molecule organic matter such as urea. Then, photocatalytic oxidation is used to convert the electrically neutral organic matter in the reverse osmosis product water into negatively charged carboxylic acids. Finally, ion exchange adsorption equipment removes these substances through ion exchange adsorption treatment, achieving high-quality purification of reclaimed water and obtaining electronic-grade source water.

[0015] Other features and advantages of this invention will be described in detail in the following detailed description section. Attached Figure Description

[0016] The above and other objects, features and advantages of the present invention will become more apparent from the accompanying drawings, in which like reference numerals generally represent like parts.

[0017] Figure 1 A schematic diagram of a system for preparing electronic-grade water from reclaimed water according to an embodiment of the present invention is shown.

[0018] Figure 2 A flowchart illustrating the operation of a system for preparing electronic-grade source water from reclaimed water according to an embodiment of the present invention is shown.

[0019] Explanation of reference numerals in the attached figures:

[0020] 1. Pretreatment equipment; 2. Hollow fiber nanofiltration equipment; 3. Reverse osmosis equipment; 4. Photocatalytic oxidation equipment; 5. Ion exchange adsorption equipment. Detailed Implementation

[0021] Preferred embodiments of the present invention will now be described in more detail. While preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to make the present invention more thorough and complete, and to fully convey the scope of the present invention to those skilled in the art.

[0022] like Figure 1 As shown, this utility model provides a system for preparing electronic-grade water source from reclaimed water, comprising:

[0023] The pretreatment equipment 1, hollow fiber nanofiltration equipment 2, reverse osmosis equipment 3, photocatalytic oxidation equipment 4, and ion exchange adsorption equipment 5 are connected in sequence. The pretreatment equipment 1 includes a filter, the hollow fiber nanofiltration equipment 2 includes a hollow fiber nanofiltration membrane, and the reverse osmosis equipment 3 includes a reverse osmosis membrane element.

[0024] Specifically, to address the problems of poor organic matter removal and low treatment efficiency in existing reclaimed water treatment technologies, this utility model provides a system for preparing electronic-grade source water from reclaimed water. This system comprises, from front to back, a pretreatment device 1 with a filter, a hollow fiber nanofiltration device 2 with a hollow fiber nanofiltration membrane, a reverse osmosis device 3 with a reverse osmosis membrane module, a photocatalytic oxidation device 4 for photocatalytic oxidation, and an ion exchange adsorption device 5 for ion adsorption. This system efficiently removes organic matter from the reclaimed water, ensuring that the ultrapure water quality at the process end meets standards. By replacing traditional water sources with reclaimed water, it alleviates the contradiction between water scarcity and the increasing demand for electronic-grade ultrapure water in my country, promotes the industrial recycling of wastewater, and can... The process achieves a high-quality and efficient transformation of reclaimed water into electronic-grade source water. The reclaimed water is filtered by pretreatment equipment 1 to remove particulate impurities and suspended solids, thus preventing physical damage to subsequent treatment equipment. Hollow fiber nanofiltration membranes are used to remove some organic matter after pretreatment, reducing the load on reverse osmosis treatment and retaining some divalent salts, thus mitigating the tendency of the concentrate to scale during reverse osmosis treatment. The reverse osmosis membrane module removes a large amount of small molecule organic matter such as urea. Then, photocatalytic oxidation is used to convert the electrically neutral organic matter in the reverse osmosis product water into negatively charged carboxylic acids. Finally, the ion exchange adsorption equipment 5 removes these substances through ion exchange adsorption treatment, achieving high-quality purification of the reclaimed water and obtaining electronic-grade source water.

[0025] Optionally, the filter's filtration accuracy is 0.45um-50um.

[0026] Specifically, the filter can be a mechanical filter, a bag filter, or a precision filter.

[0027] Optionally, the hollow fiber nanofiltration membrane can be selected with a molecular weight cutoff ranging from 250 Da to 8000 Da.

[0028] Specifically, the hollow fiber nanofiltration device 2 is preferably an external pressure type, and the hollow fiber nanofiltration membrane material can be modified polyethersulfone. According to the size of organic molecules in the reclaimed water, the molecular weight cutoff of the hollow fiber nanofiltration membrane is selected in the range of 250 Da to 8000 Da.

[0029] Optionally, the reverse osmosis membrane element is a reverse osmosis membrane element used to remove neutral molecules.

[0030] Specifically, the reverse osmosis membrane element is preferably a reverse osmosis membrane element with ultra-low pressure and high neutral molecule removal rate, with a standard desalination rate ≥99.8%, isopropanol removal rate ≥95%, SiO2 removal rate ≥99.7%, and the reverse osmosis membrane material is aromatic polyamide.

[0031] Optionally, the photocatalytic oxidation device 4 is an ultraviolet photocatalytic oxidation device 4.

[0032] Specifically, the ultraviolet photocatalytic oxidation device 4 preferably uses dual-wavelength (185nm + 254nm) ultraviolet light with an intensity of 2-10 mV / cm. 2 Ultraviolet radiation dose 200–1000 mJ / cm 2 The dwell time is 30 to 300 seconds.

[0033] Optionally, the ion exchange adsorption device 5 is equipped with ion exchange resin.

[0034] Optionally, the oxidant in the photocatalytic oxidation device is hydrogen peroxide, persulfate, or active chlorine, and the dosage of the oxidant is 5–100 mg / L.

[0035] Optionally, the ion exchange resin in the ion exchange adsorption device is a polystyrene-based gel-type weakly basic anion exchange resin, a polystyrene-based gel-type strongly basic anion exchange resin, a polystyrene-based macroporous weakly basic anion exchange resin, or a polystyrene-based macroporous strongly basic anion exchange resin.

[0036] like Figure 2 As shown, the system for preparing electronic-grade water from reclaimed water provided by this utility model operates as follows:

[0037] The reclaimed water is fed into pretreatment equipment 1 for filtration;

[0038] The filtered reclaimed water is fed into hollow fiber nanofiltration device 2 to remove some organic matter and some divalent salts;

[0039] The reclaimed water that has passed through the hollow fiber nanofiltration device 2 is fed into the reverse osmosis device 3 to remove small molecule organic matter;

[0040] The reclaimed water from the reverse osmosis unit 3 is fed into the photocatalytic oxidation unit 4 to convert electrically neutral organic matter into negatively charged carboxylic acid substances.

[0041] The regenerated water that has passed through the photocatalytic oxidation device 4 is fed into the ion exchange adsorption device 5 to adsorb and remove negatively charged carboxylic acid substances.

[0042] Specifically, this system for preparing electronic-grade water from reclaimed water has a high organic matter removal rate and stable removal effect. The reclaimed water is filtered by pretreatment equipment 1 to remove particulate impurities and suspended solids to avoid physical damage to subsequent treatment equipment. Then, hollow fiber nanofiltration can retain some organic matter and some divalent ions, reducing the reverse osmosis treatment load and alleviating membrane fouling. The subsequent treatment by the reverse osmosis membrane module can effectively retain specific small molecule organic matter. Then, through ultraviolet photocatalysis, the electrically neutral organic matter is converted into negatively charged carboxylic acids. Finally, the ion exchange resin adsorption removes the organic matter, which can further reduce the content of electrically neutral organic matter in the reverse osmosis permeate.

[0043] In summary, when using the system for preparing electronic-grade source water from reclaimed water provided by this utility model, taking the preparation of electronic-grade source water from reclaimed water from a primary wastewater treatment plant as an example: the water quality indicators of the reclaimed water are: pH 7.0, conductivity 2586 μS / cm, and TOC 7.5 mg / L; firstly, the reclaimed water enters the pretreatment unit 1 to remove particulate matter and suspended solids (SS). The pretreatment unit uses a mechanical filter with a filtration accuracy of 0.45 μm; the effluent from the pretreatment unit enters the hollow fiber nanofiltration unit 2. The hollow fiber nanofiltration unit 2 is an external pressure type, and the hollow fiber nanofiltration membrane material is modified polyethersulfone with a molecular weight cutoff of 8000 Da, a product water conductivity of 2327 μS / cm, and a TOC of 6.75 mg / L; next, the effluent from the hollow fiber nanofiltration unit 2 enters the reverse osmosis unit 3. The reverse osmosis membrane element model is TBW-HR, and the product water conductivity is 4.6 μS / cm, with a TOC of... 675ug / L; subsequently, the effluent from reverse osmosis unit 3 enters ultraviolet photocatalytic oxidation unit 4, which uses dual-wavelength (185nm+254nm) ultraviolet light with an ultraviolet intensity of 5mv / cm. 2 UV dose 500mJ / cm 2 The residence time is 150s, the oxidant is persulfate, the dosage is 20mg / L, the conductivity of the product water is 45.6us / cm, and the TOC is 340ug / L; finally, the effluent from the photocatalytic oxidation device 4 enters the ion exchange adsorption device 5, the ion exchange resin is polystyrene-based macroporous weakly basic anion exchange resin, the conductivity of the effluent is 47us / cm, and the TOC is 155ug / L.

[0044] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A system for preparing electronic-grade source water from reclaimed water, characterized in that, The system includes: The equipment comprises a pretreatment device, a hollow fiber nanofiltration device, a reverse osmosis device, a photocatalytic oxidation device, and an ion exchange adsorption device connected in sequence. The pretreatment device includes a filter, the hollow fiber nanofiltration device includes a hollow fiber nanofiltration membrane, and the reverse osmosis device includes a reverse osmosis membrane element.

2. The system for preparing electronic-grade source water from reclaimed water according to claim 1, characterized in that, The filter has a filtration accuracy of 0.45um-50um.

3. The system for preparing electronic-grade source water from reclaimed water according to claim 1, characterized in that, The hollow fiber nanofiltration membrane has a molecular weight cutoff range of 250 Da to 8000 Da.

4. The system for preparing electronic-grade source water from reclaimed water according to claim 1, characterized in that, The reverse osmosis membrane element is used to remove neutral molecules.

5. The system for preparing electronic-grade source water from reclaimed water according to claim 1, characterized in that, The photocatalytic oxidation equipment is an ultraviolet photocatalytic oxidation equipment.

6. The system for preparing electronic-grade source water from reclaimed water according to claim 1, characterized in that, The ion exchange adsorption device is equipped with ion exchange resin.

7. The system for preparing electronic-grade source water from reclaimed water according to claim 5, characterized in that, The oxidant in the photocatalytic oxidation equipment is hydrogen peroxide, persulfate, or active chlorine, and the dosage of the oxidant is 5-100 mg / L.

8. The system for preparing electronic-grade source water from reclaimed water according to claim 6, characterized in that, The ion exchange resin in the ion exchange adsorption equipment is a polystyrene-based gel-type weakly basic anion exchange resin, a polystyrene-based gel-type strongly basic anion exchange resin, a polystyrene-based macroporous weakly basic anion exchange resin, or a polystyrene-based macroporous strongly basic anion exchange resin.

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