An ultrapure water treatment system and treatment method

Abstract

An ultrapure water treatment system and a treatment method. The ultrapure water treatment system includes a primary pure water treatment unit, a pure water storage tank, a secondary pure water treatment unit, and a gas transfer sub-unit. The primary pure water treatment unit includes a first gas transfer device and an electrodialysis desalination device, and purifies primary pure water into secondary pure water. The secondary pure water treatment unit includes an ultraviolet oxidizer, a double-chamber fine processor, a second gas transfer device, and a microparticle membrane separator, and purifies secondary pure water into ultrapure water. The gas transfer sub-unit includes a third gas transfer device and a fourth gas transfer device. The inlet of the third gas transfer device receives the cathode drainage of the electrodialysis desalination device, desorbs hydrogen in the cathode drainage and transports it to the fourth gas transfer device. A part of the ultrapure water at the outlet of the microparticle membrane separator is refluxed to the fourth gas transfer device. The fourth gas transfer device dissolves the received hydrogen into the reflux water to obtain hydrogen-charged ultrapure water, and transports it to the water inlet of the double-chamber fine processor.

Description

Technical Field

[0001] The present invention relates to the technical field of ultrapure water preparation for integrated circuit manufacturing processes, and particularly to an ultrapure water treatment system and a treatment method for optimizing the utilization of power resources within the system. Background Art

[0002] Ultrapure water is a key high-purity medium in the integrated circuit manufacturing process, used for process rinsing, chemical dilution, immersion lithography, or as coolant for target devices. Its preparation, production, and supply generally consist of five parts: a pretreatment system, a deep desalination system, a polishing treatment system, a supply and circulation system, and a recovery system. The raw water is treated into primary pure water through the pretreatment system of mechanical filtration, membrane filtration, and deionization, and then secondary pure water is made through the deep desalination system and supplied to the process plant. The polishing treatment system removes trace metals, ions, particulate matter, low-molecular-weight organic compounds, and dissolved gases, and supplies ultrapure water meeting the water quality indicators at the point of delivery (POD) to the process inlet (POE).

[0003] Patent CN118239630A discloses an ultrapure water manufacturing device and method, including: a raw water tank, where the raw water is communicated with the inlet of the raw water tank; a security filter, with a filter element filter installed inside the cover of the security filter, and communicated with the outlet of the raw water tank through a raw water pump; a decarbonation membrane, with one of its outlets connected to a vacuum pump; a plurality of parallel pre-deionizers, respectively communicated with the other outlet of the decarbonation membrane; a pure water tank, communicated with the outlet of the pre-deionizer; a UV sterilizer, communicated with the outlet of the pure water tank through a pure water pump; a plurality of parallel final deionizers, respectively communicated with the outlet of the UV sterilizer; a plurality of parallel UF membranes, respectively communicated with the outlet of the final deionizer, and communicated with the ultrapure water tank from the outlets of the plurality of UF membranes. This invention uses a plurality of deionizers and UF membranes to treat ions, microparticles, and bacteria in water, but does not treat micro-pollutants such as hydrogen peroxide and dissolved oxygen generated by the ultraviolet oxidizer. These substances may affect the quality of ultrapure water, especially in fields with extremely high water quality requirements such as semiconductor manufacturing.

[0004] In the polishing treatment system of a semiconductor factory, in order to eliminate the secondary oxidizing substances generated by the ultraviolet oxidizer, metal nanoparticle catalysts can be filled in the exchanger downstream of the ultraviolet oxidizer in the polishing treatment system. Introducing external hydrogen can not only prevent the formation of an oxide layer or oxide film on the surface of the nanoparticles in the exchanger due to the increased molecular oxygen, but also increase the quenching reaction rate of the secondary oxidizing substances and enhance the catalytic activity of the nanoparticles. The hydrogen used in the factory mainly comes from electrolysis of water or hydrogen production by cracking. As a bulk gas, the supply of hydrogen is usually entrusted by the semiconductor factory to a professional gas company. The hydrogen station is arranged near the main factory building, and the hydrogen source produced or stored is transported to the distribution room through pipelines, and then distributed from the distribution room to the Fab demand points.

[0005] For example, a system for purifying water in a fine treatment circuit is disclosed in the invention patent CN115893769B. The system includes a first membrane contactor, an ultraviolet oxidizer, a weak acid adsorption tower, a double-layer polishing tower, and a second membrane contactor. Among them, the first membrane contactor is internally provided with a hydrogen dissolution membrane for preparing ultrapure water rich in hydrogen. The double-layer polishing tower is a stacked structure, including a receiving part, a supply part, and a discharge part, and eliminates the oxide layer on the surface of metal nanoparticles through a hydrogenation reaction. In this invention, hydrogen is dissolved in a part of the secondary pure water and supplied to the double-layer polishing tower together with another part of the secondary pure water treated by photolysis and weak acid adsorption. The hydrogen is provided by an external gas source, which increases the operating cost of the system and also requires additional preparation, storage, transportation, and safety management measures, resulting in a certain economic burden in actual engineering.

[0006] Therefore, how to provide an ultrapure water treatment system that can efficiently remove secondary oxidants in water, realize the recycling of waste hydrogen resources, and reduce the dependence on external hydrogen supply to improve the efficiency of ultrapure water treatment and the resource self-use rate, and solve the sustainable utilization of energy in the prior art to reduce the plant operation cost is an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0007] In view of the above-mentioned defects existing in the prior art, the present invention provides an ultrapure water treatment system and a treatment method. The system and method can not only effectively reduce the concentrations of H2O2 and DO in water by using hydrogen, but also realize the recycling of hydrogen resources by separating hydrogen in the cathode water of the electrodialysis desalination device in the system, effectively reduce the external hydrogen supply amount, improve the efficiency of ultrapure water treatment and the resource utilization rate, and reduce the operating cost per ton of water of the system.

[0008] In a first aspect, the present invention provides an ultrapure water treatment system, including a primary pure water treatment unit, a pure water storage tank, a secondary pure water treatment unit, and a gas transfer sub-unit;

[0009] The primary pure water treatment unit includes a first gas transfer device and an electrodialysis desalination device, which purify the primary pure water into secondary pure water and store it in the pure water storage tank;

[0010] The secondary pure water treatment unit includes an ultraviolet oxidizer, a double-chamber fine processor, a second gas transfer device, and a microparticle membrane separator connected in sequence, which purify the secondary pure water output from the pure water storage tank into ultrapure water;

[0011] The gas transfer sub-unit includes a third gas transfer device and a fourth gas transfer device. The inlet of the third gas transfer device receives the cathode drainage of the electrodialysis desalination device, desorbs hydrogen in the cathode drainage, and transports it to the fourth gas transfer device;

[0012] The ultra-pure water outlet of the microparticle membrane separator is connected to the ultra-pure water usage point, and part of the ultra-pure water is refluxed to the fourth gas transfer device through the first reflux pipe;

[0013] The fourth gas transfer device dissolves the received hydrogen gas into the refluxed ultra-pure water to obtain hydrogenated ultra-pure water, and transports it to the water inlet of the double-chamber fine processor.

[0014] Preferably, the first gas transfer device and the second gas transfer device respectively include a membrane type gas desorber and a vacuum device. The first gas transfer device and the second gas transfer device remove other gases including oxygen and inert gases. Removing the dissolved oxygen (DO) to an extremely low level will facilitate the effective transfer of hydrogen gas in the gas phase to the liquid phase. After the second gas transfer device, microparticles above 50 - 100 nm including bacteria are removed by the microparticle membrane separator to form ultra-pure water.

[0015] Preferably, the electro-deionization device includes a membrane stack, and the membrane stack has an independent cathode water chamber and anode water chamber. The cathode drainage generated in the cathode water chamber is pumped out and input into the gas transfer sub-unit.

[0016] In the ultra-pure water treatment system of the present invention, the water inlet of the gas transfer sub-unit comes from the primary pure water treatment unit, including the electrode chamber drainage of the electro-deionization device (EDI). Preferably, the water inlet is the cathode drainage of the electro-deionization device that can be separately shunted. The hydrogen gas in the cathode chamber water is generated by the following reaction:

[0017]

[0018] Under normal circumstances, the hydrogen gas generated in the cathode chamber will be released into the atmosphere as the mixed drainage of the electrode water chamber and the concentrated water chamber or the separate drainage of the electrode water chamber is collected in the pretreatment water tank (FWT) of the primary pure water system. Under standard conditions, through the gas transfer sub-unit, the amount of hydrogen gas C that can be recycled and mixed in the concentrated water generated by the EDI can be collected H2（STP） is:

[0019] C H2（STP） =k×I×n / Q

[0020] where, C H2（STP） has the unit of mg / L; I: the current intensity of the EDI, with the unit of ampere, A; n: the number of EDI membrane stacks; Q: the fresh water flow rate of a single membrane module, with the unit of m 3 / h; k is the engineering water volume distribution coefficient, with the unit of g / (A·h), which is determined by the design.

[0021] In the current industry, the electrodeionization device (EDI) combines the extremely dilute water chamber (mixing of cathode drainage and anode drainage) with the concentrated water chamber for combined drainage (such as Evoqua products), or the extremely dilute water chamber and the concentrated water chamber are drained separately (such as SUEZ products), but there is no separately diverted cathode drainage. To address this technological gap, the present invention innovatively separates and diverts the cathode drainage in the EDI device, and through accurate control of the current intensity and flow rate, realizes real-time estimation and optimized adjustment of the dissolved H2 concentration in the cathode drainage.

[0022] In the gas transfer sub-unit as described above, preferably, the third gas transfer device includes a membrane gas desorber and an inert gas supply facility, and the membrane gas desorber is internally provided with a hydrogen desorption membrane. The fourth gas transfer device preferably includes a membrane gas absorber, an inert gas discharge facility, and a hydrogenated ultrapure water distribution pipeline. The membrane gas absorber is internally provided with a hydrogen absorption membrane, and the gas transfer sub-unit can output hydrogenated ultrapure water with a dissolved hydrogen concentration of 0.05 mg / L or more.

[0023] Preferably, the separately diverted EDI cathode chamber drainage is led out through the extremely dilute water mixing pipe of E-Cell MK-3, with a drainage volume of 30 - 50 L / h, and collected in the cathode drainage tank (CDWT). The MK-3 concentrated water drainage flow rate is adjusted to 200 - 350 L / h (about 8 - 15% of the fresh water flow rate), and the dissolved hydrogen concentration C H2（STP） , draw the relationship curve of C H2（STP） and I, and it can be obtained that under standard conditions, the relationship formula between the dissolved hydrogen concentration C H2（STP） in the concentrated water and the current intensity I is:

[0024] C H2（STP） =(0.3 - 0.8)×I×n / Q

[0025] Among them, the unit of C H2（STP） is mg / L; I: the EDI current intensity, with the unit of ampere, A; n: the number of EDI membrane stacks; Q: the fresh water flow rate of a single membrane module, with the unit of m 3 / h; k is the engineering water volume distribution coefficient, with the unit of g / (A·h), and the value range of k is: 0.3 - 0.8, preferably 0.38 - 0.76;

[0026] According to the relationship curve, the variation relationship of the H2 dissolved concentration C H2（STP） with the current intensity I is:

[0027] ① When the current intensity I exceeds the starting current I min , C H2（STP） has a linear relationship with I, and as the current intensity I increases, C H2（STP） increases;

[0028] ② When C H2（STP）When saturation is reached, the current intensity I is increased and the H2 dissolved concentration is basically stable.

[0029] By adjusting the current intensity I of the EDI unit, the operating parameters of the third gas transfer device and the fourth gas transfer device, the H2 dissolved concentration in the hydrogen-charged ultrapure water at the water outlet of the fourth gas transfer device can be obtained, and by adjusting the mixed flow ratio of the hydrogen-charged ultrapure water and the water outlet of the ultraviolet oxidizer, the hydrogen concentration of the water entering the dual-chamber fine processor is optimized to ensure that the reaction requirements are met without wasting hydrogen and electrical energy, while achieving the purpose of improving water quality and reducing system operating costs.

[0030] The third gas transfer device and the fourth gas transfer device of the gas transfer subunit are sequentially arranged in the front stage of the double-chamber polishing treatment device, and the gas phase side is connected. The liquid phase water inlet side of the third gas transfer device is connected to the pure water pipeline or collection device of the primary pure water treatment unit, which can be exemplified by being connected to the cathode drainage tank of the electric desalination device (EDI), that is, the inlet of the third gas transfer device receives the cathode drainage of the electric desalination device, and the liquid outlet is connected to the pretreatment water tank (FWT) upstream of the primary pure water treatment unit through the second return pipe. The concentrated water at the liquid outlet has a high salt content and requires at least two stages of desalination treatment before it can be recycled. Therefore, it is returned to the pretreatment water tank through the second return pipe to increase the self-use water rate. The first gas transfer device is preferably used to remove oxygen upstream of the electric desalination device (EDI) of the primary pure water treatment unit. The liquid phase side of the fourth gas transfer device is connected to the first return pipeline of the secondary pure water treatment unit. In this case, the third gas transfer device also includes an inert gas supply facility, and an inert purge gas such as nitrogen, argon or helium is introduced into the third gas transfer device. Other inert purge gases may also be used, so that H2 in the EDI cathode drainage is desorbed to the gas phase side to achieve gas-liquid separation, and the inert gas discharge facility of the fourth gas transfer device controls the discharge of excess inert purge gas upstream to balance the internal gas pressure of the membrane gas absorber and promote the effective dissolution and absorption of hydrogen. Optionally, in order to further save inert gas, such as nitrogen resources, the nitrogen purge discharge pipeline of the inert gas discharge facility of the fourth gas transfer device is connected to the gas inlet of the second gas transfer device through a gas conveying device, and under the combined action of the vacuum pump of the second gas transfer device, more efficient removal of dissolved oxygen is achieved.

[0031] According to Henry's Law, the solubility of a component gas in a mixed gas in a liquid [C] and the equilibrium partial pressure of the gas at the gas-liquid interface [P] is proportional to the concentration of gas in the liquid phase [C] = K 0 · [P] (Gas partial pressure at the gas-liquid interface), establish the equilibrium partial pressure formula:

[0032] Vapor-phase H2 partial pressure ⇔ Z liquid-phase [H2],

[0033] When the gas-liquid reaches equilibrium, the equilibrium constant K is equal to the partial pressure P of oxygen in the gas phase H2 / the concentration [H2] of oxygen in the liquid phase, i.e., K1 = P H2 / [H2],

[0034] At a membrane interface with an equilibrium partial pressure of K1, the inert gas flows in a purging manner within the gas transfer device, preferably under vacuum conditions, and the gas-phase partial pressure P H2 Drops sharply. Since the catholyte drainage flowing in the reverse direction on the liquid phase side cannot pass through the membrane interface of the third gas transfer device, the partial pressure equilibrium formula shifts to the left. The saturated dissolved H2 with a higher partial pressure in the catholyte drainage permeates through the membrane interface of the third gas transfer device and desorbs into the gas phase, and the concentration [H2] of hydrogen in the liquid phase decreases to reach a new equilibrium K1'. Along with the purging of the inert gas, a relatively low H2 partial pressure can always be maintained within the membrane, enabling the continuously transferred hydrogen desorbed through the membrane to reach the gas phase and be carried away, thereby approaching a dynamic equilibrium, and thus completing the hydrogen desorption of the EDI catholyte drainage.

[0035] The hydrogen gas achieving gas-liquid separation enters the fourth gas transfer device. At the membrane interface of the fourth gas transfer device, the gas concentration in the liquid phase [C] = K 0 · [P] (the gas partial pressure at the gas-liquid interface), and a second equilibrium partial pressure formula is established:

[0036] Vapor-phase H2 partial pressure ⇔ Z liquid-phase [H2],

[0037] When the gas-liquid reaches equilibrium, the equilibrium constant K is equal to the partial pressure P of hydrogen in the gas phase H2 / the concentration [H2] of hydrogen in the liquid phase, i.e., K2 = P H2 / [H2].

[0038] At a membrane interface with an equilibrium partial pressure of K2, H2 is continuously introduced in a pressure manner within the fourth gas transfer device, and the gas-phase partial pressure P H2 Increases. Since the ultrapure water flowing in the reverse direction on the liquid phase side cannot pass through the membrane interface of the fourth gas transfer device, the partial pressure equilibrium formula shifts to the right. Under the condition that the partial pressures of other gases in the liquid phase are relatively low, H2 permeates through the membrane interface of the fourth gas transfer device and is absorbed by the liquid phase, and the concentration [H2] of hydrogen in the ultrapure water increases to reach a new equilibrium K2'. H2 is stripped from the catholyte drainage through the third gas transfer device and continuously introduced into the fourth gas transfer device. In the ultrapure water with reduced partial pressures of other gases, H2 is more easily absorbed by the liquid phase. The transferred H2 continuously dissolves and approaches a dynamic equilibrium, and then the preparation of hydrogenated ultrapure water is completed.

[0039] The liquid-phase effluent of the second gas transfer device preferably removes other dissolved gases to an extremely low level, and hydrogen gas in the gas phase can be more effectively transferred into the liquid phase. In addition, a first gas transfer device should be set before the EDI to desorb gases. The ultrapure water needs to undergo two-stage degassing treatment to ensure that dissolved oxygen (DO) is fully removed, thereby providing an ideal aqueous environment for the absorption of hydrogen gas. In the present invention, due to the limitation of the hydrogen source intensity, the control of other gases including dissolved oxygen (DO) in the liquid phase is more stringent.

[0040] In the present invention, the hydrogen gas recovered from the cathode drainage is dissolved into the recycled ultrapure water through the gas transfer sub-unit to form hydrogen-charged ultrapure water. The recovered hydrogen gas can be effectively dissolved in the recycled water under a certain pressure by using the Henry dissolution equilibrium principle through the fourth gas transfer device, ensuring uniform distribution and stable concentration of hydrogen gas. The generated hydrogen-charged ultrapure water and the photocatalytically treated photocatalytic water jointly enter the double-chamber fine processor, providing a continuous, appropriate, efficient, and controllable hydrogen source for the nano-metal catalyst, thereby benefiting the deep removal of oxidizing substances containing O-O bonds such as hydrogen peroxide and dissolved oxygen, and further improving the water quality and treatment efficiency of ultrapure water.

[0041] Preferably, a fourth return pipe is further provided between the ultrapure water outlet of the microparticle membrane separator and the ultrapure water usage point, which is controllably connected to the pure water storage tank to stabilize the water consumption at the ultrapure water usage point and return the remaining ultrapure water.

[0042] Preferably, a third return pipe is provided at the water outlet of the fourth gas transfer device, which is controllably connected to the pure water storage tank to regulate the mixing ratio of the hydrogen-charged ultrapure water and the effluent of the ultraviolet oxidizer.

[0043] The hydrogen-charged ultrapure water is connected to the secondary pure water treatment unit in a manner of adjusting a certain mixing ratio. The mixing ratio is preferably 3-12%, more preferably 5-10%. By using the above mixing ratio, the hydrogen gas desorbed from the cathode drainage can be rationally matched with the recycled ultrapure water, promoting the clean reaction of heterogeneous catalytic selective hydrogenation on the catalyst surface in the downstream double-chamber fine processor. When the mixing ratio is too low, the content of hydrogen-charged ultrapure water is low and cannot meet the demand for hydrogen gas in the aforementioned downstream reaction. When the mixing ratio is too high, in addition to causing waste of resources, the reaction rate of hydrogen-oxygen synthesis water may tend to decrease or be inhibited.

[0044] Preferably, the double-chamber fine processor includes a supply part, a receiving part, and a discharging part connected in sequence:

[0045] The supply part is used to supply the effluent of the ultraviolet oxidizer and the hydrogen-charged ultrapure water to the receiving part;

[0046] The receiving part includes a double-chamber structure connected in series along the water flow direction. The front chamber is filled with a supported metal nanoparticle catalyst, and the rear chamber is filled with a refined ion exchanger;

[0047] A discharge section for transporting the polished water discharged from the accommodation section to the second gas transfer device.

[0048] More preferably, a porous partition, a water distribution device and a connecting mechanism for separating the supported nano-metal catalyst and the mixed ion exchanger are provided inside the accommodation section. With such an arrangement, a double-chamber fine processor structure including a front chamber and a rear chamber is preferably formed, which can more effectively prevent the mixing of the two fillers or the disorder of the layers due to the agitation of secondary pure water, thereby ensuring the process sequence in which the secondary pure water first passes through the supported nano-metal catalyst to decompose hydrogen peroxide and continuously hydrogenate oxygen atoms into water, and then passes through the refined ion exchanger to remove dissolved ions to improve the water quality. In addition, the accommodation section can further be exemplified as an independent cylindrical structure or a tubular cavity structure.

[0049] Preferably, the supported metal nanoparticle catalyst includes a supported single-metal nanoparticle catalyst or a supported composite nanoparticle catalyst among Group VIII metals, and the dissolved H2 pressure on its surface in the kinetic reaction range should be less than 400 kPa, the dissolved H2 mass concentration should be greater than 3 μg / l, and the kinetic reaction range satisfies H2 / O2 = 0.15 - 13;

[0050] The refined ion exchanger is prepared by pre-mixing at least two ion exchange resins respectively carrying basic groups and / or acidic groups.

[0051] The supported metal nanoparticle catalyst is filled on the supply section side, and the refined ion exchanger is filled on the discharge section side.

[0052] It is further preferably to use a high-purity grade mixed ion exchange agent with a dissolved concentration of ΔTOC ≤ 1 μg / l and non-renewable. The water to be treated first passes through the supported nano-metal catalyst in the double-chamber fine processor from top to bottom, causing the H2O2 generated by the ultraviolet oxidizer to dissociate and decompose, generating by-product O2. O2 and H2 absorbed by the water phase of the gas transfer sub-unit are activated by the relatively high dissociation energy of the catalyst into adsorbed hydrogen atoms and adsorbed atomic oxygen, and thus a heterogeneous catalytic selective hydrogenation reaction occurs on the catalyst surface to synthesize H2O. This not only efficiently removes the secondary H2O2 and O2 in the secondary pure water, but also fundamentally solves the problems of surface oxidation, performance degradation, and shortened lifespan of the catalyst after long-term use, and also avoids the limited restoration steps such as interruption of operation, extraction, soaking, and cleaning and the associated pollution risks; after the secondary pure water passes through the supported nano-metal catalyst, it then passes through the refined ion exchange agent to deeply remove dissolved micro-pollutants such as trace metal ions, non-metal ions, weakly ionized inorganic salts, and residual organic impurities in the water. Compared with the traditional process, the double-chamber fine processor can not only effectively prevent the mixing of the two fillers or the disorder of the layers due to the agitation of the secondary pure water, but also avoid the degradation and decomposition of the anion exchange agent in the refined ion exchange agent by hydrogen peroxide, ensure a relatively high exchange efficiency of the exchange agent and extend its service life, and achieve the complete and effective removal of DO, H2O2, and dissolved electrolytes in the water through the catalyst and the mixed ion exchange agent.

[0053] Further research shows that an appropriate amount of H2 can enhance the overall decomposition activity of H2O2 on the surface of Group VIII metals. While increasing the decomposition rate of H2O2, it can also consume H2O2 by completely hydrogenating it to H2O. For Group VIII metals, such as Pd, under certain external conditions, the outer electron configuration 4d 10 5s 0 in which the d-orbital electrons can transition to the s-orbital, forming d-band holes and generating chemisorption, which is conducive to the activation of H2 and O2. H2 is first adsorbed on the vacant sites on the Pd surface. After being activated by the Pd catalyst, the H-H bond dissociates (the required activation energy is 4.587 kJmol -1 ) and presents as adsorbed hydrogen atoms H a , while O2 is adsorbed on separate vacant sites, and the O-O bond is not easily dissociated (the required activation energy is 49.404 kJmol -1 ) and mainly presents as adsorbed molecular oxygen (O2) on the Pd active sites a . The adsorbed hydrogen atoms and oxygen molecules first synthesize the transition state peroxide substance (OOH) a . The energy provided by the Pd active sites reaching the dissociation energy of the O-O bond is the key condition to ensure the selectivity of the catalytic oxidation reaction. Under this condition, the O-O bond breaks to form adsorbed atomic oxygen O a , and then hydrogenates with the adsorbed hydrogen atoms H a to generate adsorbed hydroxyl groups (OH)a , and then react with adsorbed hydrogen atoms H a to undergo a hydrogenation reaction to form H2O, or undergo a disproportionation reaction by adsorbed hydroxyl groups (OH) a to form H2O and adsorbed atomic oxygen O a .

[0054] By changing the ratio of H2 / O2, two significantly different kinetic intervals appear in the whole reaction process. In kinetic interval 1 (the ratio range of H2 / O2 is 0.15 - 4.0), the first-order formation rate of H2O increases with the increase of H2 pressure and shows a weak decreasing trend after reaching 380 kPa. The first-order formation rate of H2O is a single-valued function of O2 pressure. Increasing O2 pressure can increase the formation rate of H2O, while the first-order formation rate coefficient k 1st H2O depends on the reaction rate of O - O bond breaking to form adsorbed atomic oxygen O a and the reaction rate of O2 to form adsorbed molecular oxygen (O2) a , and k 1st H2O is positively correlated with both; in kinetic interval 2 (the ratio range of H2 / O2 is 4.0 - 13.0), the formation rate of H2O increases with the increase of O2 pressure and is inversely proportional to the square root of H2 pressure, that is, increasing H2 pressure will also reduce the formation rate of H2O. Therefore, for the metal nanoparticle catalyst, the dissolved H2 pressure on its surface in the kinetic reaction interval (H2 / O2 = 0.15~13) is preferably less than 400 kPa and the mass concentration is greater than 3 μg / l, which can inhibit the side reaction selectivity of H2 - O2 to form H2O2, not only ensuring that the mass concentration of H2O2 is stably controlled below 1 μg / l, but also achieving the treatment effect and purpose of finally removing the dissolved O2 to 0.1 - 0.5 μg / l or even lower at the outlet of the second gas transfer device.

[0055] Preferably, the filling capacity of the supported metal nanoparticle catalyst is 2 - 88% of the filling capacity of the refined ion exchanger, and more preferably 5 - 40%.

[0056] Preferably, the ultrapure water treatment system further includes a control unit, and the regulation content of the control unit includes but is not limited to: according to the H2 absorption concentration at the liquid phase outlet of the fourth gas transfer device, regulating the pressure of the inert gas discharge facility at its gas phase outlet to improve the hydrogen dissolution efficiency of the hydrogenated ultrapure water; according to the water output of the ultraviolet oxidizer, regulating the reflux amount of the third reflux pipe, thereby controlling the mixing ratio of the hydrogenated ultrapure water and the water output of the ultraviolet oxidizer.

[0057] Second, the present invention also provides a treatment method using the ultrapure water treatment system, including the following steps:

[0058] Step 1: The primary pure water treatment unit purifies the primary pure water into secondary pure water and stores it in the pure water storage tank, and conveys the cathode drainage of the electro - desalination device to the third gas transfer device. The third gas transfer device desorbs the hydrogen in the cathode drainage and conveys it to the fourth gas transfer device;

[0059] Step 2: The secondary pure water treatment unit purifies the secondary pure water output from the pure water storage tank into ultrapure water, and returns part of the ultrapure water to the fourth gas transfer device;

[0060] Step 3: The fourth gas transfer device dissolves the received hydrogen into the returned ultrapure water to obtain hydrogen - charged ultrapure water, and inputs it into the water inlet of the double - chamber fine processor;

[0061] Step 4: After the ultraviolet oxidizer effluent and the hydrogen - charged ultrapure water are processed by the double - chamber fine processor, the second gas transfer device and the microparticle membrane separator, fine - processed ultrapure water with an H2O2 concentration below 1 μg / l and a dissolved oxygen concentration below 0.5 μg / l is provided to the ultrapure water usage point.

[0062] Optionally, the recycled water from the semiconductor manufacturing process is collected in the pretreatment water tank upstream of the primary pure water treatment unit. The content of hydrogen peroxide in the recycled water from the semiconductor manufacturing process is slightly higher, and its decomposition will generate more oxygen. Through the resource utilization of hydrogen in the present invention, oxygen can be deeply reduced, and the hydrogen supply cost can be reduced. It is particularly suitable for the recycling of recycled water resources with a high hydrogen peroxide content, further reducing the production and usage costs of ultrapure water.

[0063] Preferably, Step 4 includes:

[0064] 4.1 Control the hydrogen - charged ultrapure water and the ultraviolet oxidizer effluent to enter the double - chamber fine processor at a mixing ratio of 3 - 12%, and flow through the supported metal nanoparticle catalyst and the refined ion exchanger in sequence to obtain fine - processed water;

[0065] 4.2 Convey the fine - processed water to the second gas transfer device for degassing treatment to obtain degassed water;

[0066] 4.3 The degassed water enters the microparticle membrane separator to remove microparticles larger than 50 nm to obtain the fine - processed ultrapure water.

[0067] Preferably, the control unit ensures the conventional circulating return water design, that is, the automatic adjustment between the amount of ultrapure water consumed at the semiconductor process water usage point and the amount of water returned to the pure water storage tank through the fourth return pipe. The dynamic matching and automatic adjustment of the real - time consumption amount and the return water amount of the process water are important guarantee objectives for the ultrapure water system design. Therefore, for other return pipes, such as the first return pipe, the return ratio should preferably not affect this design factor.

[0068] The present invention adopts a combined system of an electro - desalination device and a gas transfer sub - unit to replace the existing hydrogen - charging method with an external hydrogen source. It can rationally utilize the hydrogen - dissolving capacity of the gas transfer sub - unit and the actual hydrogen consumption in the micro - kinetic reaction of hydrogen and oxygen under the catalyst structure, controllably adjust the reflux amount of the third reflux pipe and the adapted mixing ratio, so that the mixed water of hydrogen - charged ultrapure water and the effluent of the ultraviolet oxidizer can form an optimized and efficient hydrogenation environment in the double - chamber fine processor, match the hydrogen pressure with the surface reaction activity of the catalyst, ensure the high - selectivity progress of the heterogeneous catalytic hydrogenation reaction, and thus obtain a hydrogen - charging treatment effect better than that of an external high - concentration hydrogen source, save hydrogen consumption, and reduce production costs. For the methods of desorbing hydrogen and charging hydrogen in the system, the mixing ratio of hydrogen - charged ultrapure water and the effluent of the ultraviolet oxidizer directly determines the hydrogen concentration, pressure and water quality conditions of the water body entering the double - chamber fine processor. When the mixing ratio is too low (<3%), the hydrogen concentration in the mixed water body is insufficient, which is not conducive to obtaining sufficient hydrogen sources on the catalyst surface for the hydrogenation reaction, and is likely to cause the oxygen generated by the decomposition of hydrogen peroxide or the dissolved oxygen in the secondary ultrapure water to be difficult to completely remove. When the mixing ratio is too high (>12%), the amount of hydrogen increases, which increases the dissociation barrier of the O - O bond in the adsorbed molecular oxygen or the intermediate species containing a peroxy bond in some kinetic intervals. This not only causes waste of hydrogen and an increase in the operating cost of the system, but also the continuous increase in hydrogen pressure is likely to result in an adverse tendency to reduce the H2O generation rate under specific reaction conditions.

[0069] The present invention has at least the following beneficial effects:

[0070] (1) Through the compact and continuous desorption and dissolution process of the gas transfer sub - unit, the present invention recovers the waste hydrogen generated by the electro - desalination device during the deep desalination process, prepares hydrogen - charged ultrapure water, and uses it for the subsequent fine - treatment process. This way of hydrogen resource utilization avoids dependence on external hydrogen supply, reduces operating costs, and at the same time reduces the additional facility investment required for external hydrogen preparation, storage, transportation and management. In addition, the closed - loop recovery of gas resources meets the requirements of energy conservation, environmental protection and sustainable development, effectively improves the economic and environmental protection value of the system, and promotes the green development of the membrane - based preparation technology in the high - end semiconductor manufacturing industry.

[0071] (2) Through the heterogeneous catalytic hydrogenation reaction of the supported metal nanoparticle catalyst in the double - chamber fine processor, the present invention accurately removes hydrogen peroxide generated in the ultraviolet oxidizer and oxygen generated by the catalyst. These substances will pollute the process in high - precision industries (such as nano - process semiconductor manufacturing), and advanced methods should be used to strictly control them. This system can stably control the hydrogen peroxide concentration below 1 μg / L and reduce the dissolved oxygen concentration to 0.1 - 0.5 μg / L, significantly improving the purity and quality of ultrapure water and ensuring that it meets the strict control requirements of high - index ultrapure water in the semiconductor cutting - edge process field.

[0072] (3) By adjusting the mixing ratio of hydrogenated ultrapure water and the effluent of the ultraviolet oxidizer, the present invention ensures that the amount of hydrogen entering the dual-chamber fine processor matches the surface reaction kinetics of the catalyst, forming an efficient and controllable hydrogenation environment. This not only guarantees the complete removal of hydrogen peroxide and dissolved oxygen, improves the treatment efficiency, but also prevents the formation of an oxide layer on the catalyst surface, inhibits the selectivity of adverse side reactions, fundamentally promotes the green synthesis reaction, extends the service life of the catalyst, and reduces the maintenance and replacement frequency of core consumables. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] Figure 1 It is the process flow diagram of the ultrapure water treatment system of the present invention;

[0074] Figure 2 It is the schematic diagram of the cathode drainage generation in the membrane stack of the electro-desalting device of the present invention;

[0075] Figure 3 It is the curve graph of the dissolved concentration of H2 in the influent of the cathode drainage tank varying with I in the embodiment of the present invention;

[0076] Figure 4 It is the analysis of the influence of multiple mixing ratios on the concentrations of H2 and O2 in the mixed hydrogenated water and the O2 concentration at the outlet of the dual-chamber fine processor of the present invention.

[0077] DESCRIPTION OF THE REFERENCE NUMERALS: 100 - pure water storage tank, 11 - first membrane type gas desorber, 111 - first vacuum device, 112 - first nitrogen charging facility, 12 - electro-desalting device, 21 - ultraviolet oxidizer, 22 - dual-chamber fine processor, 23 - second membrane type gas desorber, 231 - second vacuum device, 24 - microparticle membrane separator, 30 - cathode drainage, 31 - third membrane type gas desorber, 32 - second nitrogen charging facility, 33 - fourth gas transfer device, 400 - ultrapure water usage point. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0078] In order to better understand the above technical solution, the following will describe the above technical solution in detail in combination with the specification and specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0079] The terms used in the embodiments of the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. The singular forms "a", "the" and "said" used in the embodiments of the present invention and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise. "Multiple" generally includes at least two.

[0080] It should also be noted that the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a commodity or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such commodity or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the commodity or device comprising said element.

[0081] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0082] As Figure 1 shown, the present invention provides an ultra-pure water treatment system, specifically including:

[0083] (1) The primary pure water treatment unit purifies primary pure water into secondary pure water and transports the secondary pure water to the pure water storage tank 100. Specifically, it includes a first gas transfer device and an electrodialysis desalination device 12. The cathode effluent of the electrodialysis desalination device 12 is connected to the gas transfer sub-unit; the first gas transfer device includes a first membrane type gas desorber 11, a first vacuum device 111 and a first nitrogen filling facility 112 connected to the first membrane type gas desorber 11; the cathode drainage 30 of the electrodialysis desalination device 12 enters the third gas transfer device of the gas transfer sub-unit.

[0084] See Figure 2 , the electrodialysis desalination device 12 includes a membrane stack, the membrane stack has an independent cathode chamber and anode chamber, and the cathode drainage generated in the cathode chamber is pumped out and input into the gas transfer sub-unit. Specifically, at the cathode and anode of the membrane stack, the cathode chamber is isolated by a cation exchange membrane, and the anode chamber is isolated by an anion exchange membrane. A large amount of available hydrogen ions exist in the cathode drainage of the cathode chamber. After obtaining electrons, they are reduced to H2.

[0085] (2) The secondary pure water treatment unit treats the secondary pure water in the pure water storage tank 100 into ultra-pure water, including the following connected in sequence:

[0086] 2.1) An ultraviolet oxidizer 21. The effluent of the ultraviolet oxidizer 21 is mixed with the effluent of the gas transfer sub-unit and then introduced into a double-chamber fine processor 22;

[0087] 2.2) The double-chamber fine processor 22 includes a supply part, a receiving part and a discharge part connected in sequence;

[0088] The supply part is used to supply the effluent of the ultraviolet oxidizer 21 and hydrogen-filled ultra-pure water to the receiving part;

[0089] The containment section, including a tandem dual-chamber structure, is respectively filled with a supported metal nanoparticle catalyst and a refined ion exchanger; it receives the water supply from the supply section;

[0090] The discharge section is used to transport the refined water discharged from the containment section to the second gas transfer device;

[0091] In the containment section, the supported metal nanoparticle catalyst is filled on the supply section side, the refined ion exchanger is filled on the discharge section side, and the two are stacked along the water flow direction. The filling height of the supported metal nanoparticle catalyst is 2 - 88% of the filling height of the refined ion exchanger, preferably 5 - 40%;

[0092] The supported metal nanoparticle catalyst includes a supported single metal nanoparticle catalyst or a supported composite nanoparticle catalyst among Group VIII metals. The dissolved H2 pressure on its surface in the kinetic reaction range is less than 400 kPa, the dissolved H2 mass concentration is greater than 3 μg / l, and the kinetic reaction range satisfies H2 / O2 = 0.15 - 13; the refined ion exchanger is prepared by pre-mixing at least two ion exchange resins respectively carrying basic groups and / or acidic groups;

[0093] 2.3) The second gas transfer device is arranged between the dual-chamber fine processor 22 and the microparticle membrane separator 24, and includes a second membrane type gas desorber 23 and a second vacuum device 231 connected thereto. The water inlet of the second membrane type gas desorber 23 is in communication with the effluent of the dual-chamber fine processor 22. The second membrane type gas desorber 23 and the second vacuum device 231 are used to remove other gases including oxygen and inert gases;

[0094] 2.4) The microparticle membrane separator 24 is used to remove microparticles above 50 nm - 100 nm including bacteria. It is arranged at the outlet of the second membrane type gas desorber 23, is in communication with the ultrapure water usage point 400, and returns part of the ultrapure water to the fourth gas transfer device 33 and / or the pure water storage tank 100;

[0095] (3) The gas transfer sub-unit includes:

[0096] 3.1) The third gas transfer device includes a third membrane type gas desorber 31 and a second nitrogen filling facility 32 connected thereto. The third gas transfer device receives the cathode drainage 30 of the electro - desalting device 12 and desorbs the hydrogen in the cathode drainage 30. The third gas transfer device also includes a water inlet pipe connected upstream of the first gas transfer device, and returns the cathode brine after desorbing hydrogen to the pretreatment water tank upstream of the primary pure water treatment unit.

[0097] 3.2) The fourth gas transfer device 33, including a membrane gas absorber, is used to receive the hydrogen gas transported by the third gas transfer device; dissolve the received hydrogen gas into the recirculated ultrapure water to obtain hydrogenated ultrapure water, and transport it to the water inlet of the double-chamber fine processor 22.

[0098] (4) The control unit regulates multiple links of the ultrapure water treatment system, including but not limited to:

[0099] ① On the basis of ensuring and stabilizing the water consumption at the ultrapure water usage point 400, automatically regulate the recirculation ratio of the fourth return pipe returning to the pure water storage tank 100;

[0100] ② Adjust the amount of ultrapure water output by the microparticle membrane separator 24 entering the first return pipe and recirculating to the fourth gas transfer device 33, so as to determine the total amount of hydrogenated ultrapure water produced by the fourth gas transfer device 33. On this basis, regulate the water volume of the third return pipe to ensure that the mixing ratio of the hydrogenated ultrapure water output by the gas transfer sub-unit and the water output of the ultraviolet oxidizer 21 in the mixer is 3-12%, more preferably 5-10%;

[0101] ③ When it is detected that the quality of the secondary pure water deteriorates, without affecting the process water consumption, part of the ultrapure water output by the microparticle membrane separator can be recirculated to the upstream pretreatment water tank (FWT) of the primary pure water treatment unit to actively control the water supply quality of the pure water storage tank 100.

[0102] The treatment method of the ultrapure water treatment system specifically includes the following steps:

[0103] Step 1: The primary pure water treatment unit purifies the primary pure water into secondary pure water, and transports the cathode drainage 30 of the electrodialysis desalination device 12 to the third gas transfer device, and the third gas transfer device desorbs the hydrogen gas in the cathode drainage and transports it to the fourth gas transfer device 33;

[0104] Step 2: The secondary pure water treatment unit purifies the secondary pure water into ultrapure water, and recirculates part of the ultrapure water to the fourth gas transfer device 33;

[0105] Step 3: The fourth gas transfer device 33 dissolves the received hydrogen gas into the recirculated ultrapure water to obtain hydrogenated ultrapure water, and inputs it into the water inlet of the double-chamber fine processor 22;

[0106] Step 4: The hydrogenated ultrapure water and the water output of the ultraviolet oxidizer 21 enter the double-chamber fine processor 22 in a controlled mixing ratio of 3-12%, more preferably 5-10% in the mixer. After being processed by the double-chamber fine processor 22, the second gas transfer device and the microparticle membrane separator 24, provide fine-processed ultrapure water with an H2O2 concentration of less than 1 μg / l and a dissolved oxygen concentration of less than 0.5 μg / l to the ultrapure water usage point 400;

[0107] It is processed by the double-chamber fine processor 22, specifically including the following steps:

[0108] 4.1 The water output from the ultraviolet oxidizer 21 and the hydrogen-charged ultrapure water flow through the supported metal nanoparticle catalyst and the refined ion exchanger in the double-chamber fine processor in sequence to obtain the finely processed water;

[0109] 4.2 The finely processed water is transported to the second gas transfer device for degassing treatment to obtain the degassed water;

[0110] 4.3 The degassed water enters the microparticle membrane separator 24 to remove microparticles above 50 nm to obtain the refined ultrapure water.

[0111] In the above process, the control unit regulates multiple links of the ultrapure water treatment system. On the basis of ensuring that the water consumption and water quality at the ultrapure water use point meet the standards and are stable, it controls the first return pipe and regulates the return flow rate of the third return pipe to ensure the mixing ratio of the hydrogen-charged ultrapure water and the water output from the ultraviolet oxidizer 21.

[0112] Example 1

[0113] An ultrapure water treatment system and treatment method specifically include:

[0114] (1) The primary pure water treatment unit purifies the primary pure water into secondary pure water;

[0115] It includes a first gas transfer device and an E-Cell MK-3 electrodialysis desalination device connected in sequence, and a separately shunted EDI cathode chamber drain is led out by a mixed discharge pipe, with a drainage volume of 40 L / h, which is collected in the cathode drainage tank (CDWT). The MK-3 concentrated water drainage flow rate is adjusted to 300 L / h (about 10% of the fresh water flow rate), and the working current intensity is 1.7 A;

[0116] (2) The secondary pure water treatment unit purifies the secondary pure water into ultrapure water, including the following connected in sequence:

[0117] 2.1) The ultraviolet oxidizer. The water output from the ultraviolet oxidizer is mixed with the hydrogen-charged ultrapure water flowing out of the gas transfer sub-unit and then introduced into the double-chamber fine processor. The mixing ratio of the hydrogen-charged ultrapure water and the water output from the ultraviolet oxidizer entering the mixer is 3%;

[0118] 2.2) The double-chamber fine processor includes a supply part, a housing part, and a discharge part connected in sequence;

[0119] a. The supply part is used to supply the water output from the ultraviolet oxidizer and the hydrogen-charged ultrapure water to the housing part;

[0120] b. A receiving portion, comprising a dual-chamber structure connected in series, which is filled with a supported metal nanoparticle catalyst and a refined ion exchanger, respectively; the supported metal nanoparticle catalyst is filled on the supply side, and the refined ion exchanger is filled on the discharge side, and both are stacked along the water flow direction, and the filling capacity of the supported metal nanoparticle catalyst is 10% of the filling capacity of the refined ion exchanger;

[0121] The supported metal nanoparticle catalyst includes a supported single metal nanoparticle catalyst or a supported composite nanoparticle catalyst in a Group VIII metal, the surface of which has a dissolved H2 pressure of less than 400 kPa in the kinetic reaction interval, a dissolved H2 mass concentration of greater than 3 μg / l, and a kinetic reaction interval that satisfies H2 / O2=0.15-13; the refined ion exchanger is prepared by premixing two ion exchange resins having a basic group and an acidic group, respectively;

[0122] c. a discharge portion for delivering the refined treated water discharged from the receiving portion to the second gas transfer device;

[0123] 2.3) A second gas transfer device, connected to the effluent water of the double chamber polishing device, for removing other gases including oxygen and inert gases, including a second membrane gas desorber and a vacuum pump;

[0124] 2.4) A microparticle membrane separator is used to remove microparticles larger than 50 nm including bacteria. It is installed at the outlet of the second gas transfer device, connected to the pipeline network that transports ultrapure water to the ultrapure water use point, and diverts part of the ultrapure water to the fourth gas transfer device.

[0125] (3) Gas transfer subunit, including:

[0126] 3.1) A third gas transfer device, which is used to receive cathode drainage from the electric desalination device and desorb hydrogen in the cathode drainage, specifically including: a third membrane gas desorber and a nitrogen purge facility.

[0127] 3.2) The fourth gas transfer device includes a membrane gas absorber for receiving the hydrogen delivered by the third gas transfer device; dissolving the received hydrogen into the refluxed ultrapure water to obtain hydrogen-filled ultrapure water, and delivering it to the water inlet of the dual-chamber polishing device. In order to further save nitrogen resources, the nitrogen purge exhaust pipeline of the fourth gas transfer device is connected to the inlet of the second gas transfer device through a gas delivery device, and in combination with a vacuum pump, more efficient removal of dissolved oxygen is achieved.

[0128] Example 2

[0129] The difference between this embodiment and embodiment 1 is that in this embodiment, the mixing ratio of the hydrogen-filled ultrapure water and the outlet water of the ultraviolet oxidizer is 12%.

[0130] Example 3

[0131] The difference between this embodiment and embodiment 1 is that the mixing ratio of the hydrogen-filled ultrapure water and the outlet water of the ultraviolet oxidizer in this embodiment is 6%.

[0132] Comparative Example 1

[0133] The difference between this comparative example and Example 3 is that the mixing ratio of the hydrogen-charged ultrapure water and the outlet water of the ultraviolet oxidizer in this comparative example is 2%.

[0134] Comparative Example 2

[0135] The difference between this comparative example and Example 3 is that the mixing ratio of the hydrogen-charged ultrapure water and the outlet water of the ultraviolet oxidizer in this comparative example is 15%.

[0136] Test methods and results

[0137] (1) The E-Cell MK-3's polar water mixing pipe is led out to the EDI cathode chamber drainage with a separate diversion, with a drainage volume of 40L / h, which is collected in the cathode drainage trough (CDWT). The MK-3 concentrated water drainage flow rate is adjusted to 300L / h (about 10% of the fresh water flow rate), connected to the membrane gas desorber (MGD) liquid phase outlet, and returned to the upstream pretreatment water tank (FWT) of the primary pure water treatment unit after merging. When the MK-3 current intensity I is adjusted and changes between 1 and 2A, the H2 dissolved concentration C at the inlet of the cathode drainage trough (CDWT) is plotted. H2（STP） The test results are as follows: Figure 3 As shown. Figure 3 It can be seen that:

[0138] ① In actual production, the H2 dissolved concentration is related to the relatively stable polar water supply;

[0139] ②When the current intensity I exceeds the starting current I min , C H2（STP） It is linearly related to I. As the current intensity I increases, C H2（STP） Increase;

[0140] ③When C H2（STP） When saturation is reached, the current intensity I is increased and the H2 dissolved concentration is basically stable.

[0141] According to the test results, the current intensity I=1.7A can ensure that the EDI outlet water resistivity is greater than 17.8MΩ.cm, and is also an economical choice that takes both H2 dissolved concentration and energy consumption into consideration. Therefore, this data is used in all embodiments.

[0142] (2)Based on the test conditions of Example 3, after the fourth gas transfer device absorbs H2 in ultrapure water, the opening of the hydrogenated water valve is adjusted to control the mixing ratio of 6% and supply it to the double-chamber fine processor. After fine treatment to remove H2O2, O2 and soluble microelectrolytes, the residual dissolved gas is removed through the second gas transfer device, and cross-flow filtration of microparticles is carried out through the microparticle membrane separator to form ultrapure water. Using three analyzers, Dextens 62101, Orbisphere 510 and Aero-Laser 2021, the concentration changes of H2, O2 and H2O2 in the secondary pure water treatment system are detected respectively and recorded in Table 1:

[0143] Table 1 Online detection data of the mass concentrations of H2, O2 and H2O2 in the secondary pure water treatment system

[0144]

[0145] In the table, CDWT - cathode drain tank, MGD - the third gas transfer device, MGA - the fourth gas transfer device, DLB-P - double-chamber fine processor, MGD-P - the second gas transfer device.

[0146] It can be seen from the above test data that H2 in the cathode water obtains a concentration of 5.21 μg / l in the mixed hydrogenated water at the inlet of the double-chamber fine processor through desorption and absorption. On the catalyst surface, 28.1 μg / l of H2O2 formed by the recombination of hydroxyl radicals is quenched to 0.7 μg / l. The H2 in the mixed hydrogenated water can remove the O2 generated by the quenching reaction and the O2 in the water (a total of about 19.11 μg / l) to 0.97 μg / l, realizing the effective substitution of the hydrogen source.

[0147] (3)The test measured the effect of removing O2 from the mixed hydrogenated water at multiple mixing ratios, and the test results are as Figure 4 shown.

[0148] As Figure 4 can be seen, increasing the mixing ratio can increase the H2 concentration in the mixed hydrogenated water and slightly reduce the O2 concentration in the mixed hydrogenated water, and can ensure that the O2 at the outlet of the double-chamber fine processor (the inlet of the second gas transfer device) reaches a better level of less than 0.9 μg / l. For example, the mixing ratio in Example 1 is 3%, the mixing ratio in Example 3 is 6%, and the mixing ratio in Example 2 is 12%, all of which can better reduce the O2 concentration.

[0149] From the change trend of the residual O2 at the outlet of the double-chamber fine processor, it can be seen that as the H2 concentration in the hydrogenated water increases, the O2 concentration only drops from 0.98 μg / l to 0.93 μg / l, and the decline is not obvious. On the premise of ensuring the dissolved oxygen removal effect, considering the conservation of ultrapure water resources and gas energy, adopting the hydrogenated water mixed flow method and appropriately reducing the mixed flow ratio, such as setting the mixed flow ratio at 3-12%, preferably 5-10%, is a more economical choice.

[0150] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications to these embodiments once they learn the basic creative concept. Therefore, the present invention is intended to be construed as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention. Obviously, those skilled in the art can make various changes and variations to the present invention without departing from the spirit and scope of the present invention.

Claims

1. A method for treating ultrapure water, characterized in that: The steps include: Step 1: A primary pure water treatment unit includes a first gas transfer device and an electric desalination device, which purifies the primary pure water into secondary pure water and stores it in a pure water storage tank, and transports the cathode drainage of the electric desalination device to a third gas transfer device, which desorbs hydrogen from the cathode drainage and transports it to a fourth gas transfer device; the third gas transfer device also includes a second reflux pipe, which refluxes the cathode salt water after desorbing hydrogen to a pre-treatment water tank upstream of the primary pure water treatment unit; Step 2: A secondary pure water treatment unit, comprising an ultraviolet oxidizer, a dual-chamber polishing device, a second gas transfer device and a microparticle membrane separator connected in sequence, purifies the secondary pure water output from the pure water storage tank into ultrapure water, and refluxes part of the ultrapure water to the fourth gas transfer device through the first reflux pipe; Step 3: the fourth gas transfer device dissolves the received hydrogen into the refluxed ultrapure water to obtain hydrogen-filled ultrapure water, and transports the hydrogen-filled ultrapure water to the water inlet of the dual-chamber polishing device; Step 4: After the effluent from the ultraviolet oxidizer and the hydrogen-filled ultrapure water are treated by a double-chamber polishing device, a second gas transfer device and a microparticle membrane separator, the ultrapure water with a H2O2 concentration below 1μg / L and a dissolved oxygen concentration below 0.5μg / L is provided to the ultrapure water use point.

2. The method for treating ultrapure water according to claim 1, characterized in that: Step 4 includes: The hydrogen-charged ultrapure water and the outlet water of the ultraviolet oxidizer are controlled to enter the double-chamber polishing treatment device at a mixed flow ratio of 3-12%, and flow through the supported metal nanoparticle catalyst and the refined ion exchanger in sequence to obtain refined treated water; The refined treated water is transported to the second gas transfer device for degassing to obtain degassed water; The degassed water enters the microparticle membrane separator to remove microparticles larger than 50 nm, thereby obtaining the refined ultrapure water.

3. The method for treating ultrapure water according to claim 1 or 2, characterized in that: The first gas transfer device and the second gas transfer device include a membrane gas desorber and a vacuum device, respectively.

4. The method for treating ultrapure water according to claim 1 or 2, characterized in that: The electric desalination device comprises a membrane stack having an independent cathode water chamber and an anode water chamber. The cathode drainage produced in the cathode water chamber is extracted and input into a third gas transfer device.

5. The method for treating ultrapure water according to claim 4, characterized in that: The third gas transfer device includes a membrane gas desorber and an inert gas supply facility; The fourth gas transfer device includes a membrane gas absorber and an inert gas exhaust facility.

6. The method for treating ultrapure water according to claim 5, characterized in that: A fourth reflux pipe is also provided between the ultrapure water outlet of the microparticle membrane separator and the ultrapure water use point, which is connected to the pure water storage tank in a controlled manner to stabilize the water consumption at the ultrapure water use point and reflux the remaining ultrapure water.

7. The method for treating ultrapure water according to claim 5, characterized in that: The water outlet of the fourth gas transfer device is provided with a third reflux pipe, which is controllably connected to the pure water storage tank to adjust the mixed flow ratio of the hydrogen-filled ultrapure water and the outlet water of the ultraviolet oxidizer.

8. The method for treating ultrapure water according to any one of claims 5 to 7, characterized in that: The dual-chamber finishing processor comprises a supply portion, a receiving portion and a discharge portion which are connected in sequence: A supply unit, used for supplying mixed flow of ultraviolet oxidizer water and hydrogen-filled ultrapure water to the receiving unit; The receiving part includes a double-chamber structure connected in series along the water flow direction, the front chamber is filled with a supported metal nanoparticle catalyst, and the rear chamber is filled with a refined ion exchanger; The discharge part is used to transport the refined treated water discharged from the receiving part to the second gas transfer device.

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