Embedded device and method for efficiently removing urea in ultrapure water production

Abstract

The invention relates to the technical field of water treatment, and discloses an embedded device and method for efficiently removing urea in ultrapure water production. According to the embedded device for efficiently removing urea in ultrapure water production provided by the invention, the chlorinating agent supply unit and the ultraviolet treatment unit are introduced into a conventional ultrapure water system, so that a urea removal system is embedded into the conventional ultrapure water production system; a urea removal system does not need to be additionally arranged outside an ultrapure water production system, so that the occupied area of equipment is remarkably reduced, and the removal operation process of urea in ultrapure water is simplified.

Description

Technical Field

[0001] The present invention relates to the technical field of water treatment, and in particular to an embedded device and method for efficiently removing urea in ultrapure water production. Background Art

[0002] Electronic-grade ultrapure water is a fundamental raw material in the semiconductor industry, requiring high volumes and quality. To ensure the ultrapure water's exceptional quality and meet the demands of the semiconductor industry, the production process is complex. Typical ultrapure water production processes include multi-stage reverse osmosis (RO) treatment, multi-stage ion exchange resin treatment, and ultraviolet (UV) treatment.

[0003] Urea, with the chemical formula CO(NH2)2, is a small organic molecule commonly found in daily life. It is the primary product of mammalian protein metabolism, one of the most commonly used agricultural fertilizers, and a crucial industrial raw material, present in a wide range of water bodies. Urea can penetrate ultrapure water production lines, potentially causing excessive TOC levels in the produced water and reducing chip production yields, presenting a technical challenge in ultrapure water production. Therefore, efficient urea removal is crucial for producing ultrapure water from unconventional water sources, such as recycled water, to overcome water resource constraints and ensure the yield of semiconductor manufacturing products.

[0004] In the related art, methods for removing urea mainly include biological methods, physical adsorption methods, enzymatic methods, chemical oxidation methods, and advanced oxidation methods. However, the urea removal technologies in the related art are inefficient and are not suitable for the efficient removal of low-concentration urea. Summary of the Invention

[0005] The purpose of the present invention is to provide an embedded device and method for efficiently removing urea in ultrapure water production, so as to solve the problem that urea is difficult to remove in the ultrapure water production process.

[0006] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is:

[0007] In a first aspect, the present invention provides an embedded device for efficient removal of urea in ultrapure water production, the device comprising a cation bed, a decarbonization tower, an anion bed, a chlorinating agent supply unit, and an ultraviolet treatment unit;

[0008] Wherein, the chlorinating agent supply unit is configured to supply the chlorinating agent to the effluent water of the cation bed after the cation bed and before the ultraviolet treatment unit;

[0009] The ultraviolet treatment unit is arranged between the decarbonization tower and the cathode bed, and is used for emitting ultraviolet light to irradiate the ultrapure water added with the chlorinating agent flowing through the ultraviolet treatment unit.

[0010] In an optional embodiment, the chlorination agent supply unit is configured to supply the chlorination agent to the effluent water of the cation bed after the cation bed and before the decarbonization tower;

[0011] And / or, the hydraulic retention time of the decarbonization tower is set to be no less than 5 minutes, so that the effluent from the cationic bed can be chlorinated.

[0012] In an optional embodiment, the embedded device further includes:

[0013] A chlorination unit is provided between the cationic bed and the ultraviolet treatment unit, and the chlorination agent supply unit is provided to supply the chlorination agent to the effluent water of the cationic bed after the cationic bed and before the chlorination unit;

[0014] And / or, the hydraulic retention time of the chlorination unit is set to be no less than 5 minutes, so that the effluent from the cathodic bed can be chlorinated.

[0015] For example, when a chlorination unit is provided, the chlorination unit can be provided before or after the decarbonization tower. When the chlorination unit is provided after the decarbonization tower, the chlorination agent supply unit can supply the chlorination agent to the ultrapure water before or after the decarbonization tower.

[0016] In an optional embodiment, the cationic bed includes a weak cationic bed and a strong cationic bed, and the chlorinating agent supply unit is configured to supply the chlorinating agent to the cationic bed outlet water of the strong cationic bed after the strong cationic bed;

[0017] And / or, the anion bed includes a weak anion bed and a strong anion bed, and the ultraviolet treatment unit is arranged between the decarbonization tower and the weak anion bed.

[0018] In an optional embodiment, the ultraviolet treatment unit is provided with a dual-wavelength ultraviolet light source, and the dual-wavelength ultraviolet light source can simultaneously emit ultraviolet light with wavelengths of 185nm and 254nm;

[0019] And / or, the hydraulic retention time of the ultraviolet treatment unit is set to be no less than 2 minutes.

[0020] In an optional embodiment, the embedded device further comprises one or more pumps to enable the ultrapure water to flow in its flow direction, and / or to enable the chlorinating agent supply unit to provide the chlorinating agent according to a preset metering amount.

[0021] In an optional embodiment, the chlorinating agent supply unit is configured to supply the chlorinating agent so that the active chlorine concentration in the ultrapure water added with the chlorinating agent is more than 5 times the urea concentration.

[0022] In a second aspect, the present invention provides an ultrapure water production system, comprising the above-mentioned embedded device.

[0023] In a third aspect, the present invention provides a method for efficiently removing urea in ultrapure water production, using the above-mentioned embedded device, comprising the following steps:

[0024] Supplying a chlorinating agent to the effluent water from the cathodic bed of the embedded device and chlorinating the water to obtain chlorinated water;

[0025] treating the chlorinated water with ultraviolet radiation to obtain ultraviolet-treated water;

[0026] The ultraviolet treated water is allowed to enter the cathode bed of the embedded device.

[0027] In an optional embodiment, the chlorination is carried out in a decarbonization tower of the embedded device;

[0028] Alternatively, the chlorination is carried out in a chlorination unit arranged after the decarbonization tower of the embedded device.

[0029] In an optional embodiment, when the chlorinating agent is supplied to the cation bed outlet water of the embedded device, the active chlorine concentration in the ultrapure water added with the chlorinating agent is made to be more than 5 times the urea concentration;

[0030] And / or, the chlorination time is not less than 5 minutes;

[0031] And / or, the ultraviolet irradiation time is not less than 2 minutes;

[0032] And / or, the ultraviolet light wavelength of the ultraviolet irradiation is 185nm and 254nm.

[0033] The technical solution of the present invention has at least the following beneficial effects:

[0034] (1) The embedded device for efficient removal of urea in ultrapure water production provided by the present invention introduces a chlorinating agent supply unit and an ultraviolet treatment unit into a conventional ultrapure water production system, thereby embedding the urea removal system into the conventional ultrapure water production system. There is no need to re-install the urea removal system outside the ultrapure water production system, which significantly reduces the equipment footprint and simplifies the operation process of removing urea from ultrapure water.

[0035] In addition, in the technical solution of the present invention, the chlorinating agent supply unit is configured to supply the chlorinating agent to the effluent water of the cation bed after the cation bed of the embedded device, and the ultraviolet treatment unit is arranged between the decarbonization tower and the anion bed of the embedded device and is used to perform ultraviolet irradiation treatment on the ultrapure water after chlorination. That is, the present invention embeds the urea removal system between the cation bed and the anion bed of the conventional ultrapure water production system. Through this design, on the one hand, the low pH property of the effluent water of the cation bed can be directly utilized (the cation bed replaces the cations in the ultrapure water with hydrogen ions, so that the pH value of the effluent water of the cation bed is less than 3) for urea removal treatment, without the need for additional addition of acidifying agents, which can reduce production costs and avoid the introduction of other impurity ions; on the other hand, the ultraviolet treatment unit performs ultraviolet irradiation treatment on the ultrapure water, which can make the electrically neutral organic matter in the ultrapure water carry a charge, which is conducive to improving the removal effect of the subsequent anion bed on this part of the organic matter.

[0036] (2) The embedded device for efficient removal of urea in ultrapure water production provided by the present invention has a chlorinating agent supply unit configured to supply chlorinating agent to the effluent of the cation bed after the cation bed and before the decarbonization tower, and the hydraulic retention time of the decarbonization tower is configured to be no less than 5 minutes, so that the effluent of the cation bed can be chlorinated. By limiting the supply position of the chlorinating agent and the hydraulic retention time of the decarbonization tower, the decarbonization tower can simultaneously complete the removal of carbon dioxide and the chlorination of ultrapure water, eliminating the need for an additional chlorination treatment site, which can further reduce the equipment footprint and simplify the production process. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0038] Figure 1 The structure diagram of the embedded device according to the first embodiment of the present invention is schematically shown;

[0039] Figure 2 The schematic diagram of the structure of a conventional ultrapure water production system is shown;

[0040] Figure 3 FIG2 schematically shows a structural diagram of an embedded device according to Embodiment 2 of the present invention.

[0041] Description of reference numerals:

[0042] 1. Weak cationic bed; 2. Strong cationic bed; 3. Decarbonization tower; 4. UV treatment unit; 5. Weak cationic bed; 6. Strong cationic bed; 7. Chlorination agent supply unit; 8. Water inlet pump; 9. Dosing pump; 10. Chlorination unit. DETAILED DESCRIPTION

[0043] To further illustrate the technical means and results employed by the present invention to achieve its intended objectives, the following describes in detail the specific implementations, technical solutions, and features of the present invention using preferred embodiments. The specific features, structures, or characteristics of the various embodiments described below may be combined in any suitable manner.

[0044] If no specific experimental steps or conditions are specified in the examples, the conventional experimental steps or conditions described in the literature in this field can be used. If the manufacturer of the reagents or instruments is not specified, they are all commercially available conventional reagents.

[0045] The present invention is further described in detail below with reference to specific examples. These examples should not be construed as limiting the scope of protection claimed in the present invention.

[0046] Example 1

[0047] This embodiment provides an embedded device for efficient removal of urea in ultrapure water production. Figure 1 The schematic diagram of the structure of the embedded device of this embodiment is shown schematically.

[0048] like Figure 1 As shown, the embedded device of this embodiment includes, in sequence, a weak cation bed 1, a strong cation bed 2, a decarbonization tower 3, an ultraviolet treatment unit 4, a weak anion bed 5, a strong anion bed 6, and a chlorinating agent supply unit 7. Along the flow direction of ultrapure water, the weak cation bed 1, the strong cation bed 2, and the decarbonization tower 3 are connected in sequence, and the weak anion bed 5 and the strong anion bed 6 are connected.

[0049] A chlorinating agent supply unit 7 is configured to supply a chlorinating agent to the cation bed effluent of the cation bed 2 between the cation bed 2 and the decarbonization tower 3. The chlorinating agent can be a reagent that provides active chlorine, such as sodium hypochlorite. Furthermore, the chlorinating agent supply unit 7 is configured to supply the chlorinating agent so that the active chlorine concentration in the ultrapure water to which the chlorinating agent is added is at least five times the urea concentration. The hydraulic retention time of the decarbonization tower 3 is set to be no less than 5 minutes.

[0050] The UV treatment unit 4 is disposed between the decarbonization tower 3 and the weak anion bed 5 and is in communication with each of the two, emitting ultraviolet light to irradiate the ultrapure water flowing through the decarbonization tower 3 and the weak anion bed 5. The UV treatment unit 4 is equipped with a dual-wavelength UV light source capable of simultaneously emitting UV light at wavelengths of 185 nm and 254 nm. The hydraulic retention time of the UV treatment unit 4 is set to be no less than 2 minutes.

[0051] In addition, a water inlet pump 8 is provided on the waterway between the strong cationic bed 2 and the decarbonization tower 3 to ensure that the ultrapure water flows in its direction. A dosing pump 9 is also provided on the waterway between the chlorination agent supply unit 7 and the decarbonization tower 3 to ensure that the chlorination agent supply unit 7 provides the ultrapure water with a preset dosage of chlorination agent.

[0052] When the system starts operating, a certain concentration of chlorinating agent (e.g., sodium hypochlorite solution) in the chlorinating agent supply unit 7 is pumped into the inlet water of the decarbonization tower 3 via the dosing pump 9, causing the ultrapure water to mix in the decarbonization tower 3 and achieve urea chlorination. The water sample then enters the ultraviolet treatment unit 4 for efficient urea removal. When the device starts operating, the ultraviolet treatment unit 4 must first be turned on, followed by the dosing pump 9 and the water inlet pump 8, which must be turned on and properly adjusted to ensure that the active chlorine concentration of the mixed solution in the inlet water of the decarbonization tower 3 is at least 5 times the urea concentration. At the same time, the HRT of the decarbonization tower 3 must be ensured to exceed 5 minutes, and the HRT of the ultraviolet treatment unit 4 must exceed 2 minutes.

[0053] The above-mentioned embedded device of this embodiment can be embedded in any conventional ultrapure water production system that uses a 2B3T system or a 4B5T system to produce ultrapure water, and there is no restriction on the specific composition of the "conventional ultrapure water production system". As long as a 2B3T system or a 4B5T system is installed therein, it can be replaced by the embedded device of this embodiment.

[0054] For example, a "conventional ultrapure water production system" may be Figure 2 The ultrapure water production system shown includes a pretreatment section, a polishing section, and a polishing section. The pretreatment section may include a water tank, a heat exchanger, a multi-media filter, an activated carbon filter, a 2B3T system, or a 4B5T system, among other devices for pre-treating incoming water. The polishing section may include a reverse osmosis device, an ultraviolet treatment device, an ion resin mixed bed, a primary degassing membrane, a heat exchanger, and other devices for polishing incoming water. The polishing section may include a secondary ultraviolet treatment device, a polishing resin bed, a secondary degassing membrane, a terminal ultrafiltration system, and other devices for polishing incoming water.

[0055] Example 2

[0056] This embodiment provides an embedded device for ultrapure water production. Figure 3 The schematic diagram of the structure of the embedded device of this embodiment is shown schematically.

[0057] like Figure 3As shown, the embedded device of this embodiment includes, in sequence, a weak cation bed 1, a strong cation bed 2, a decarbonization tower 3, a chlorination unit 10, a UV treatment unit 4, a weak anion bed 5, a strong anion bed 6, and a chlorination agent supply unit 7. Along the flow direction of ultrapure water, the weak cation bed 1, the strong cation bed 2, and the decarbonization tower 3 are connected in sequence, and the weak anion bed 5 and the strong anion bed 6 are connected.

[0058] The chlorination unit 10 is located after the decarbonization tower 3, and the UV treatment unit 4 is located between the chlorination unit 10 and the weak anion bed 5. A chlorinating agent supply unit 7 is configured to supply a chlorinating agent to the anion bed effluent between the decarbonization tower 3 and the chlorination unit 10. The chlorinating agent can be a reagent that provides active chlorine, such as sodium hypochlorite. Furthermore, the chlorinating agent supply unit 7 is configured to supply the chlorinating agent so that the active chlorine concentration in the ultrapure water to which the chlorinating agent is added is at least five times the concentration of urea. The hydraulic retention time of the chlorination unit 10 is set to be no less than 5 minutes.

[0059] The decarbonization tower 3, chlorination unit 10, UV treatment unit 4, and weak anion bed 5 are sequentially connected. The UV treatment unit 4 is configured to emit ultraviolet light to irradiate the ultrapure water flowing through the unit, which has been treated with a chlorinating agent. The UV treatment unit 4 is equipped with a dual-wavelength UV light source capable of simultaneously emitting UV light at wavelengths of 185 nm and 254 nm. The hydraulic retention time of the UV treatment unit 4 is set to no less than 2 minutes.

[0060] In addition, a water inlet pump 8 is provided on the waterway between the strong cationic bed 2 and the decarbonization tower 3 to ensure that the ultrapure water flows in its direction. A dosing pump 9 is also provided on the waterway between the chlorination agent supply unit 7 and the chlorination unit 10 to ensure that the chlorination agent supply unit 7 provides the ultrapure water with a preset dosage of chlorination agent.

[0061] The above-mentioned embedded device of this embodiment can also be embedded in any conventional ultrapure water production system that uses a 2B3T system or a 4B5T system to produce ultrapure water, and will not be described in detail.

[0062] The above description is merely a preferred embodiment of the present invention; however, the scope of protection of the present invention is not limited thereto. Any person skilled in the art who, within the technical scope disclosed by the present invention, makes equivalent substitutions or modifications based on the technical solutions and improved concepts of the present invention shall be covered by the scope of protection of the present invention.

Claims

1. An embedded device for efficient removal of urea in ultrapure water production, characterized in that: The device comprises a cation bed, a decarbonization tower, a cathode bed, a chlorinating agent supply unit and an ultraviolet treatment unit; Wherein, the chlorinating agent supply unit is configured to supply the chlorinating agent to the effluent water of the cation bed after the cation bed and before the ultraviolet treatment unit; The ultraviolet treatment unit is arranged between the decarbonization tower and the cathode bed, and is used for emitting ultraviolet light to irradiate the ultrapure water added with the chlorinating agent flowing through the ultraviolet treatment unit.

2. The embedded device according to claim 1, wherein: The chlorinating agent supply unit is configured to supply chlorinating agent to the effluent water of the cation bed after the cation bed and before the decarbonization tower; And / or, the hydraulic retention time of the decarbonization tower is set to be no less than 5 minutes, so that the effluent from the cationic bed can be chlorinated.

3. The embedded device according to claim 1, wherein: The embedded device further comprises: A chlorination unit is provided between the cationic bed and the ultraviolet treatment unit, and the chlorination agent supply unit is provided to supply the chlorination agent to the effluent water of the cationic bed after the cationic bed and before the chlorination unit; And / or, the hydraulic retention time of the chlorination unit is set to be no less than 5 minutes, so that the effluent from the cathodic bed can be chlorinated.

4. The embedded device according to any one of claims 1 to 3, characterized in that: The cationic bed includes a weak cationic bed and a strong cationic bed, and the chlorinating agent supply unit is configured to supply the chlorinating agent to the cationic bed outlet water of the strong cationic bed after the strong cationic bed; And / or, the anion bed includes a weak anion bed and a strong anion bed, and the ultraviolet treatment unit is arranged between the decarbonization tower and the weak anion bed.

5. The embedded device according to any one of claims 1 to 3, characterized in that: The ultraviolet treatment unit is provided with a dual-wavelength ultraviolet light source, which can simultaneously emit ultraviolet light with wavelengths of 185nm and 254nm; And / or, the hydraulic retention time of the ultraviolet treatment unit is set to be no less than 2 minutes.

6. The embedded device according to any one of claims 1 to 3, characterized in that: The embedded device further includes one or more pumps to enable the ultrapure water to flow in its flow direction, and / or to enable the chlorinating agent supply unit to provide the chlorinating agent according to a preset metering amount.

7. The embedded device according to any one of claims 1 to 3, characterized in that: The chlorinating agent supply unit is configured to supply the chlorinating agent so that the active chlorine concentration in the ultrapure water to which the chlorinating agent is added is 5 times or more the urea concentration.

8. An ultrapure water production system, characterized in that: The ultrapure water production system comprises the embedded device according to any one of claims 1 to 7.

9. A method for efficiently removing urea in ultrapure water production, using the embedded device according to any one of claims 1 to 7, characterized in that: The steps include: Supplying a chlorinating agent to the effluent water from the cathodic bed of the embedded device and chlorinating the water to obtain chlorinated water; treating the chlorinated water with ultraviolet radiation to obtain ultraviolet-treated water; The ultraviolet treated water is allowed to enter the cathode bed of the embedded device.

10. The method according to claim 9, characterized in that When supplying a chlorinating agent to the outlet water of the cathodic bed of the embedded device, the active chlorine concentration in the ultrapure water to which the chlorinating agent is added is made to be more than 5 times the urea concentration; And / or, the chlorination time is not less than 5 minutes; And / or, the ultraviolet irradiation time is not less than 2 minutes; And / or, the ultraviolet light wavelength of the ultraviolet irradiation is 185nm and 254nm.

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