Water treatment system for the production of sterile water

Abstract

Water treatment system (2) for the production of sterile water, in particular for a beverage bottling plant, with a pre-filtration unit (8) which is arranged in an inlet line for reverse osmosis water and is designed to remove foreign substances such as sealing residues and metal particles, a UV disinfection unit (10) with a UV light source, preferably with a wavelength of 254 nm, the irradiation duration and irradiation intensity of which can be controlled depending on a flow rate and water quality parameters of the reverse osmosis water, a sterile filtration unit (11) comprising at least one filter membrane, preferably with a nominal pore size of 0.2 µm or 0.22 µm, and which is preferably made of a material from the group consisting of polyethersulfone, PES, polyvinylidene fluoride, PVDF, cellulose acetate or nylon, a Clean-In-Place (CIP) cleaning unit, comprising a fresh water tank, a hot water tank, an acid tank, a caustic tank and / or a heating unit, each of which is fluidically connected to a piping system of the water treatment system (2) via solenoid valves; a sterilization-in-place (SIP) sterilization unit which is configured to generate steam via a steam generation unit and to feed the steam at a predetermined temperature for a predetermined time into the water treatment system (2), and a sterile gas filtration unit which is designed to filter and process a supply gas necessary for the operation of the water treatment system (2) from a supply gas tank.

Description

Technical field

[0001] The present invention relates to a water treatment system for the production of sterile water. In particular, the invention relates to integrated systems that combine functions such as filtration, UV disinfection, sterilization, cleaning, and integrity testing of filter membranes to ensure the reliable production of sterile water. Conventional water treatment systems are used in industries with stringent requirements for the quality of sterile water, such as the pharmaceutical, food, biotechnology, and electronics industries, and offer significant advantages, especially in the beverage manufacturing process. Background of the invention

[0002] The treatment / production of sterile water is a critical and essential process in various industries, and the quality of the produced water directly impacts the safety and reliability of the final products. Existing technologies for producing sterile water have several limitations. For example, conventional filtration systems often struggle to efficiently capture or retain microorganisms and contaminants, resulting in inconsistent water quality. The cleaning and sterilization processes in these systems are often not systematically optimized or optimally coordinated, leading to a higher risk of microbial residue. Furthermore, the lack of integration between functional units such as filtration, cleaning, sterilization, and leak detection results in operational inefficiencies and increased maintenance costs and effort.

[0003] Sterilization filters, a key component in sterile water treatment, are designed to remove all living microorganisms, including bacteria, fungi, and viruses, from liquids. However, in existing systems, these filters often face challenges such as limited material compatibility, difficulties in ensuring long-term sterility, and inadequate integration with other system components. These shortcomings lead to fluctuations in sterile water quality and prevent the high standards required for modern industrial production. Brief description of the present invention

[0004] Therefore, the present invention aims to avoid or at least mitigate the disadvantages described above and, in particular, to provide a water treatment system for the production of sterile water which, through the interaction of several components, stably produces sterile water that meets the requirements of international standards such as the USP (United States Pharmacopeia) and EP (European Pharmacopoeia) and fulfills the stringent requirements of industries such as the pharmaceutical and biotechnology sectors. Furthermore, the system should ensure safe operation even in the event of a failure of individual components, thereby reducing the risk of microbial contamination of the entire water treatment system.

[0005] This problem is solved by a water treatment system according to the features of claim 1. Advantageous embodiments are claimed in the dependent claims and / or are explained below.

[0006] The invention therefore relates firstly to a water treatment system for producing sterile water, in particular for a beverage bottling plant, comprising a pre-filtration unit / pre-filtration unit arranged in an inlet line for reverse osmosis water, which is supplied in particular from a reverse osmosis water tank and is designed for the (coarse) removal of foreign substances such as sealing residues, metal particles or similar contaminants, and a UV disinfection unit comprising a UV light source, preferably emitting UV light with a wavelength of 254 nm, the irradiation duration and intensity of which are controllable depending on a flow rate and water quality parameters of the reverse osmosis water. Preferably, the water treatment system can have a plurality of sensors designed for detecting the (flow) rate and the quality parameters of the reverse osmosis water.Furthermore, the water treatment system comprises a sterile filtration unit, which has at least one filter membrane / filter element, preferably with a nominal pore size of 0.2 µm or 0.22 µm, and which is preferably made of a material from the group consisting of polyethersulfone, PES, polyvinylidene fluoride, PVDF, cellulose acetate or nylon, and a clean-in-place (CIP) cleaning unit, which has a fresh water tank, a hot water tank, an acid tank, a caustic tank and / or a heating device, each of which is fluidically connected to a (pipe) piping system of the water treatment system via solenoid valves.Furthermore, the water treatment system comprises a sterilization-in-place (SIP) sterilization unit, which is configured to generate steam via a steam generation unit and to feed the steam into the water treatment system at a predetermined temperature for a predetermined time, as well as a sterile gas filtration unit, which is configured to filter and treat the supply gas, preferably compressed compressed air or nitrogen, necessary for the operation of the water treatment system, in particular for the operation of the at least one filter membrane, from a supply gas tank, which can then be supplied to or is supplied to the water treatment system.

[0007] In other words, the water treatment system according to the invention includes a CIP cleaning unit designed to perform various cleaning processes with the tanks for fresh water, hot water, acid, and / or alkali described above, in order to achieve different levels of system cleanliness, effectively remove dirt and microbial residues from the entire water treatment system, including the piping system, and ensure the continuous, stable operation of the water treatment system as well as the quality of the sterile water treatment. The SIP sterilization unit is designed to ensure thorough sterilization of all components and piping of the water treatment system by supplying hot steam generated by the steam generation unit.

[0008] Furthermore, the components of the water treatment system described above are interconnected via the piping system, particularly in the form of pipelines, and preferably in series. The water treatment system also includes a control unit, preferably a higher-level one, which is electronically connected to the components of the water treatment system described above, thus forming a closed system for the treatment of sterile water.

[0009] In other words, the CIP cleaning unit, depending on the cleaning program, enables different levels of cleaning (cold water, hot water, acid, alkali) and removes organic and inorganic residues as well as microorganisms from the entire system. The SIP sterilization unit, using saturated steam, ensures the complete sterilization of all components and lines of the water treatment system. All components are connected via a piping system, preferably arranged in series, and are linked to a central control unit. The combined interaction of these components enables the stable production of sterile water, reduces the risk of microbial contamination, extends the system's service life, and lowers maintenance costs.The combination of UV disinfection and membrane filtration reduces energy consumption compared to conventional thermal processes and is particularly suitable for partially replacing heat treatments in beverage production (e.g., for highly acidic products or carbonated beverages). This saves chemicals and water, optimizes the production process, and yields ecological and economic benefits.

[0010] Through the interaction of these multiple components, the water treatment system can advantageously produce consistently sterile water. Regular cleaning and sterilization of the various components and piping systems by the CIP cleaning unit and the SIP sterilization / disinfection unit reduces the risk of microbial growth and blockages throughout the entire system, thereby extending its lifespan and advantageously lowering maintenance costs.

[0011] The use of combined UV disinfection and membrane filtration technologies reduces the energy consumption of conventional heat treatment. In beverage manufacturing, this technology is particularly suitable for partially replacing heat treatment in the production of highly acidic products, thereby not only saving energy effectively but also reducing the use of chemicals. In wet aseptic lines, it can replace bottle rinsing water and water used to rinse the bottle neck, thus reducing water consumption. Specifically, it can replace heat treatment for sterilizing carbonated beverages before carbonation, thereby optimizing the production process. This technology is also particularly suitable for the production of sterile carbonated beverages using gas.Efficient sterile water treatment ensures product quality, improves production efficiency, and achieves both economic benefits and high environmental protection value.

[0012] According to an advantageous aspect of the invention, the sterile filtration unit can include a leak detection / leakage testing unit which is configured and prepared to perform an integrity test before and after each sterile water production process or cycle to verify the integrity of at least one filter membrane, thus ensuring reliable sterile water treatment. In other words, the leak detection unit (or alternatively, the higher-level control unit connected to the leak detection unit) is configured to perform an integrity test before each sterile water production cycle by the water treatment system and an integrity test after each production cycle on the respective filter membranes.

[0013] In a further advantageous aspect of the invention, the leak detection unit can be configured to perform the respective integrity tests of the at least one filter membrane by completely wetting the at least one filter membrane with liquid or reverse osmosis water, increasing the pressure on the at least one filter membrane using the supply gas, and subsequently measuring the pressure at which the first bubbles escape from the at least one filter membrane, i.e., by means of a bubble pressure test. In this bubble pressure test, a pressure is determined at which the first continuous bubble formation through the largest pores of the completely wetted filter membrane is detected. The pressure at which the supply gas from the supply gas side of the corresponding filter membrane displaces the liquid / reverse osmosis water in the largest pore and the first bubbles escape is the so-called bubble point.The leak detection unit is configured to detect bubble formation and identify the corresponding filter membrane as damaged or defective if the measured pressure is lower than the specified bubble point. In other words, after the filter membrane is completely wetted with liquid, pressure is built up using sterile gas, and the pressure at which the first continuous bubbles escape is determined. If the measured pressure is below the setpoint, the membrane is considered damaged. Alternatively or additionally, the leak detection unit can be configured to perform the respective integrity tests of the at least one filter membrane by completely wetting the at least one filter membrane with liquid or by...The test involves using reverse osmosis water and setting a predetermined constant pressure across at least one filter membrane using the supply gas. The flow rate of this supply gas exiting the filter membrane is then measured using a diffusion test. A pressure is applied below the bubble point described above, meaning below the pressure at which the supply gas displaces the liquid / reverse osmosis water in the largest pore of the filter membrane, causing the first bubbles to emerge. The supply gas diffuses through the liquid in the pores of the filter membrane, and the flow rate is measurable by the leak detection unit and compared to a predetermined limit value to determine the integrity of the filter membrane.This enables comprehensive and continuous integrity testing. Thus, the leak detection unit of the water treatment system according to the invention allows real-time monitoring of any leaks in the respective filter membranes of the sterilization filter. In combination with stringent verification standards, the risk of sterility can be minimized. In other words, a constant gas pressure is applied below the bubble pressure, and the amount of gas diffusing through the wetted membrane is measured. Comparison with limit values ​​allows for the evaluation of integrity.

[0014] Preferably, the leak detection unit further comprises a membrane wetting device, a pressure injection device, and a pressure monitoring module. Based on the bubble pressure test or diffusion test described above, these components are configured to pre-wet the respective filter membrane before the sterile water production cycle, in particular by means of the membrane wetting device, and subsequently inject sterile gas at a pressure that meets the requirements of a membrane supplier, in particular by means of the pressure injection device. The pressure change is monitored in real time by the pressure monitoring module of the leak detection unit to accurately determine the integrity of the filter membrane. After completion of the production cycle, the integrity of the filter membrane is checked again to ensure the safety of the water treatment system throughout the entire production cycle.

[0015] According to a preferred embodiment of the invention, the sterile filtration unit can comprise a first membrane module comprising at least one filter membrane and a second membrane module comprising at least one filter membrane, and the leakage detection unit can be configured to perform integrity tests separately for each of the two membrane modules before and after each production cycle / manufacturing process for the sterile water, and to automatically determine a microbial risk in the water treatment system based on a comparison of the results of the integrity tests with a plurality of predefined decision scenarios.

[0016] Furthermore, the use of multiple membrane modules ensures the safe operation of the water treatment system even if one of the membrane modules fails, thereby further reducing the risk of microbial contamination.

[0017] According to a further advantageous aspect of the invention, the leak detection unit can be configured to determine the microbial risk based on the predefined decision scenarios / cases described below. In the event that the integrity tests before and after a manufacturing process / production cycle of the sterile water for the first membrane module as well as for the second membrane module (by the leak detection unit) are determined to be successful, the leak detection unit is configured to determine a low microbial risk.In the event that the integrity tests prior to a sterile water production process for both the first and second membrane modules are determined to be passed, but the integrity test after the production process for either the first or second membrane module is determined to be failed, the leak detection unit is configured to determine a low microbial risk. Conversely, in the event that the integrity tests prior to a sterile water production process for both the first and second membrane modules are determined to be passed, but the integrity tests after the production process for both the first and second membrane modules are determined to be failed, the leak detection unit is configured to determine a high microbial risk.

[0018] In other words, the leak detection unit is configured to classify the microbiological risk as low if all integrity tests before and after a sterile water production cycle on both membrane modules are found to be passed; and to classify the microbiological risk as low if only the integrity test on the first membrane module or the second membrane module after the production cycle is found to be failed. This is because, in the dual-membrane module configuration, if a problem occurs in one of the membrane modules, the other membrane module can still ensure effective removal of microorganisms from the system, thus reducing the risk of contamination of the sterile water. Therefore, the failure of a single membrane module does not affect the overall filtration efficiency of the water treatment system.The leak detection unit is also configured to classify the microbiological risk as high if both integrity tests on the first and second membrane modules fail after the production cycle. This indicates the need for timely system inspection and maintenance, and potentially replacement of the defective membrane module to restore the system's sterile water reprocessing capacity. Furthermore, the dual-membrane module design, combined with the respective integrity tests before and after each production cycle, improves system stability and reduces production downtime due to filtration failures.

[0019] Preferably, each membrane module can have multiple filter membranes, and the number and size of the filter membranes can be adjusted according to the actual water requirements. Both single-stage and two-stage series connection modes are supported. A preferably pleated filter membrane structure further increases the filter surface area. In combination with the depth filtration principle, a microbial capture rate of 99.999% can be guaranteed, thereby significantly reducing the risk of sterility caused by filter membrane leakage.

[0020] According to a further advantageous aspect of the invention, the leak detection unit can be configured to automatically generate a warning message for a user in the event that a high microbiological risk has been determined, and preferably either to put the system into a safe state or to interrupt operation in order to avoid contamination of sterile water.

[0021] According to a further preferred embodiment of the invention, the CIP cleaning unit can be configured to perform cleaning programs such as rinsing, hot water, alkali (caustic) and acid cleaning, and to clean / rinse the water treatment system via the piping system.

[0022] According to a further advantageous aspect of the invention, the SIP sterilization unit can include a steam pressure control system and a temperature control system, and be configured to feed the steam generated by the steam generation unit into the water treatment system at a predetermined pressure and to maintain a temperature of 121 °C to 126 °C in the water treatment system for a period of 30 to 45 minutes. The combination with the steam pressure control system ensures thorough sterilization of all components and the piping system of the water treatment system. In a particularly preferred embodiment of the invention, the sterile gas filtration unit can include a three-stage filter system.

[0023] The compressed air or nitrogen required for the operation of the water treatment system can thus be subjected to three-stage filtration and high-temperature sterilization treatment, thereby counteracting secondary contamination / pollution by the supply gas.

[0024] Insofar as process steps or sequences are described in the following description or in the drawings, this information serves only to explain the function and intended purpose of the water treatment system according to the invention. These process steps are not the subject of the patent application as an independent process, but rather illustrate the configuration of the device (e.g., the control unit) that is set up to carry out these steps.

[0025] Furthermore, a method for producing sterile water is disclosed, using a water treatment system according to the invention. The method comprises the following steps: pre-filtration of reverse osmosis water by a pre-filtration unit arranged in an inlet line, whereby foreign substances such as sealing residues and metal particles are removed; disinfection of the pre-filtered reverse osmosis water by a UV disinfection unit with a UV light source, preferably with a wavelength of 254 nm, wherein the irradiation time and intensity are controlled as a function of a measured flow rate and water quality parameters; and filtration of the UV-treated reverse osmosis water by at least one filter membrane of a sterile filtration unit, wherein the at least one filter membrane is preferably made of a material from the group consisting of polyethersulfone (PES), polyvinylidene fluoride (PVDF), cellulose acetate, or nylon.

[0026] Preferably, the process comprises the following additional steps before the step of pre-filtering the reverse osmosis water and / or after the step of filtering the reverse osmosis water: cleaning the water treatment system by a CIP cleaning unit, comprising at least one of the following steps: rinsing with fresh water, rinsing with hot water, rinsing with acid solution and / or alkaline solution, wherein the respective liquids are supplied to the water treatment system from a fresh water tank, a hot water tank, an acid tank and an alkaline tank via a piping system and controllable solenoid valves; sterilizing the water treatment system by supplying steam to the water treatment system by a SIP sterilization unit, wherein the steam is supplied to the water treatment system from a steam generation unit at a predetermined temperature and for a predetermined duration.and filtering a supply gas from a supply gas tank through a sterile gas filtration unit. This means that the steps of cleaning by the CIP cleaning unit and sterilizing by the SIP sterilization unit can be carried out before and / or after the sterile water production cycle.

[0027] The procedure prior to the step of pre-filtering the reverse osmosis water may include an additional step: performing an integrity test of the at least one filter membrane by a leak detection unit, in particular using a bubble pressure test or a diffusion test.

[0028] Preferably, the process can include an additional step after the step of filtering the UV-treated reverse osmosis water: performing an integrity test of the at least one filter membrane by a leak detection unit. That is, the integrity test step can be performed before or after the sterile water production cycle. Particularly preferably, the integrity test step is performed both before and after the production cycle. If the previously described optional steps of cleaning the water treatment system by a CIP cleaning unit and sterilizing the water treatment system by introducing steam into the water treatment system by a SIP sterilization unit (before and / or after the sterile water production cycle) are performed, an integrity test step can be performed after each sterilization step.

[0029] According to a preferred aspect of the invention, the above-described step of performing an integrity test of the at least one filter membrane can further comprise: completely wetting the at least one filter membrane with the reverse osmosis water, and increasing the pressure on the at least one filter membrane using the supply gas and measuring the pressure at which first gas bubbles escape from the at least one filter membrane, or setting a predetermined constant pressure on the at least one filter membrane using the supply gas, and measuring a flow rate of the supply gas exiting the at least one filter membrane.

[0030] In a preferred embodiment of the invention, the sterile filtration unit can comprise a first membrane module with at least one filter membrane and a second membrane module with at least one filter membrane, and the leak detection unit can perform separate integrity tests for the first membrane module and the second membrane module. The leak detection unit then automatically determines a microbial risk in the water treatment system based on a comparison of the integrity test results with a plurality of predefined decision scenarios.

[0031] An exemplary process flow for the production of sterile water is now described. The reverse osmosis water first enters the pre-filtration unit, where initial impurities are filtered out. The pre-filtered water is then fed into the UV disinfection unit, where the UV irradiation parameters of the UV light source are dynamically adjusted according to the water quality data to reduce the initial microbial load in the water. The UV-disinfected water then flows into the sterile filtration unit, and sterility is achieved through depth filtration by at least one filter membrane / filter element of the sterilization filter. Before entering the filter membrane and after completion of the entire production cycle, the integrity of the at least one filter membrane is also checked.The water treatment system regularly performs a CIP cleaning program, which includes at least one of the following steps: Hot water cleaning, in which approximately 80-90 °C hot water is drawn from the hot water tank and circulated through the water treatment system for approximately 30 to 90 minutes to further soften and remove stubborn contaminants; Cleaning with alkaline solution, especially sodium hydroxide, in which a 0.5% to 2% sodium hydroxide solution is prepared, the alkaline solution is then heated to approximately 60 to 70 °C, and the water treatment system, including the piping system, is flushed for approximately 60 to 120 minutes to effectively remove organic contaminants such as proteins and oils; Cleaning with acidic solution, in which a 1% to 3% citric acid or phosphoric acid solution is prepared, the acidic solution is heated to approximately 50 to 60 °C, and the water treatment system, including the piping system, is flushed for approximately 60 to 120 minutes.45 to 90 minutes to remove inorganic salt deposits and other substances from the water treatment system; starting the SIP sterilization and disinfection program, which, for example, involves steam purging of the components and lines with steam at a temperature of approximately 121 to 126 °C for approximately 30 to 45 minutes, particularly with pressure and temperature control, after CIP cleaning, as well as filtration, preferably a three-stage filtration process with thermal sterilization, of the supply gas, which is fed from a supply gas tank to prevent secondary contamination; and subsequent cooling of the entire water treatment system to room temperature. It should be noted that the steps of CIP cleaning, SIP sterilization, sterile gas filtration, and integrity testing are optional, both before and after the production cycle.The process enables the production of sterile water for high-risk applications, e.g., in the cleaning of equipment and packaging or for the production of acidic drinks and carbonated sterile products.

[0032] Before and after the production cycle, the integrity of at least one filter membrane is checked by the leak detection unit. Once the check is successful and deemed passed, the sterile gas filtration unit is activated to supply the water treatment system with supply gas, and the sterile water production cycle described above is then carried out. The sterile water produced is suitable for applications with a high microbial risk, such as sterile water for cleaning equipment / packaging and for the production of products with a high acid content.

[0033] Furthermore, an exemplary procedure for the system installation and connection of the water treatment system according to the invention is described below.

[0034] Install the pre-filtration unit in series with the main water line for the reverse osmosis water. Connect the UV disinfection unit (with flow sensors) downstream of the pre-filtration unit, ensuring a tight seal, for example, by using a quick-connect clamp interface, and provide a water flow sensor to ensure linkage control. Depending on the water demand, install the appropriate number of sterilization-grade filter membranes in the membrane modules of the sterile filtration unit and connect the sterile filtration unit to the outlet of the UV disinfection unit using a flange connection.Connect the clean water tank, hot water tank, acid tank, alkali tank, and heating element of the CIP cleaning unit, which are connected to the system via piping to ensure that the appropriate cleaning solution can flow through all system components requiring cleaning. Sealed pipe fittings are used at the connection points to prevent leakage of the cleaning solution. Next, route the steam line of the SIP sterilization unit so that it covers the main system components (pre-filtration unit, UV disinfection unit, sterile filtration unit, and the corresponding piping). When installing the piping, it is essential to pay attention to its slope to facilitate condensate drainage, specifically ensuring a gradient for condensate removal.Configure the appropriate pressure injection device and pressure monitoring module of the leak detection unit and connect this leak detection unit to the sterile filtration unit to ensure the tightness of the connecting line and to prevent pressure leaks from affecting the detection result during the integrity check procedure. Install the sterile gas filtration unit and adjust the steam line required for sterilization. After completion of the installation, a gas leak test is performed.

[0035] The preferred system checks and integrity tests of the first and second membrane modules of the sterile filtration unit before and after a sterile water production cycle have been described above, in order to make an assessment of the microbial risk. The following section describes, as examples, the procedure for a system check at a supplier's site for the technical acceptance of the new sterile water production line, as well as the procedure for a system check during installation at the factory.For system verification at a supplier for technical acceptance, the verification includes the following steps: conducting a supplier selection to ensure that a supplier with qualifications and technical strength is chosen; conducting a review of the production line design standard to ensure that the design of the production line meets the requirements for sterile water treatment; conducting a review of membrane performance and testing the performance of the filter membranes at the supplier's site; and conducting a review of the filter membrane integrity to ensure that there is no damage or other problem that could impair the filtering effect before the filter membrane(s) are put into operation.For system verification during installation at the factory, the verification includes the following steps: conducting an installation qualification to verify that the beverage bottling plant installation meets the design requirements and relevant standards; subsequently conducting an operational qualification / functional qualification to test the various performance indicators of the beverage bottling plant under normal operating conditions; conducting a new membrane media test to test the filtration performance of the newly installed membrane(s); conducting a beverage production and acceptance test, simulating the actual beverage production process and accepting the produced sterile water, including performing tests of UV virus inactivation, filter performance, and performance tests in the production process, such as testing the sterile water quality.When the membrane(s) have reached the end of their service life, perform a second media test to evaluate the performance of the membrane(s) at the end of their service life. Brief description of the characters

[0036] The invention is explained in more detail below with reference to advantageous embodiments and the accompanying figures. These show: Fig. 1 a schematic representation of a beverage bottling plant with a water treatment system for sterile water according to a preferred embodiment of the invention, and a downstream aseptic bottling plant; Fig. 2 a flowchart of a process for producing sterile water using the water treatment system according to the invention; and Fig. 3 a schematic flow diagram of a process for producing sterile water using the water treatment system according to the invention, in combination with appropriate cleaning and sterilization steps.

[0037] The figures are purely schematic and serve solely to illustrate the present invention. It should be noted that the features of the individual embodiments are interchangeable and may occur in specific combinations. Detailed description of preferred embodiments

[0038] The present invention is described below with reference to the preferred embodiments. Fig. 1 to 3 described.

[0039] Fig. Figure 1 schematically shows a preferred embodiment of a water treatment system 2 with a downstream aseptic filling system 4. In particular, the technical design and process control of the water treatment system 2 for producing sterile water for use in the aseptic filling system 4 are illustrated. In this embodiment, the water treatment system 2 has a reverse osmosis water tank 6 as a source of reverse osmosis water, from which the reverse osmosis water is discharged to a downstream pre-filtration unit 8, which is designed for the initial removal of foreign substances such as sealing residues and metal particles.The reverse osmosis water is then directed into a UV disinfection unit 10, which is configured to irradiate the incoming reverse osmosis water with UV radiation, preferably with a wavelength of 254 nm, to achieve an initial reduction of the microbial load through photochemical DNA damage. Downstream is a sterile filtration unit 11 comprising a first membrane module 12 and a second membrane module 14, which are preferably connected in series. Each of these is provided with at least one filter membrane, the nominal pore size of which is preferably 0.2 µm or 0.22 µm. The filter membranes are preferably made of materials such as polyethersulfone (PES), polyvinylidene fluoride (PVDF), cellulose acetate, or nylon.The design with two separate membrane modules 12, 14 enables redundant operation of the water treatment system 2, thus ensuring the microbiological safety of the produced sterile water even if one of the two membrane modules 12, 14 fails. The treated sterile water is fed to a first aseptic tank 16, which serves as a buffer tank and from which the sterile water is supplied for the subsequent processing steps. The first aseptic tank 16 can also be supplied with process water from a UHT unit 18, which is designed to perform UHT (ultra-high temperature) treatment of the process water. Preferably, a second aseptic tank 20 is arranged in the aseptic filling system 4, which is also supplied with process water from another UHT unit 18.Both UHT units 18 are configured to thermally sterilize the process water from an upstream mixing tank 22. The sterile water is then fed from the first aseptic tank 16 and the second aseptic tank 20 via an in-line mixing device 24, which is configured, for example, to continuously add further liquid components (e.g., syrup or concentrates) to the sterile water during the production flow, to a mixing device 26. In the mixing device 26, the sterile water or the mixture is aerated with CO2 gas, which is introduced via a separate carbonator 28. The finished mixture or beverage is fed via the mixing device 26 to a filling device 30, which fills the preferably CO2-aerated mixture into suitable containers, in particular bottles. The CIP cleaning unit and the SIP sterilization unit are not shown in this figure.

[0040] Fig. Figure 2 shows a flowchart of a process for producing sterile water, in particular with the water treatment system 2 described above, according to a preferred embodiment of the invention. The step "Producing S0 of the sterile water" comprises the following steps: pre-filtering S0.1 of reverse osmosis water by a pre-filtration unit 8 arranged in an inlet line, whereby foreign substances such as sealing residues and metal particles are separated; disinfecting S0.2 of the pre-filtered reverse osmosis water by a UV disinfection unit 10 with a UV light source, preferably with a wavelength of 254 nm, the irradiation duration and intensity of which are controlled depending on a measured flow rate and water quality parameters; and filtering S0.3 of the UV-treated reverse osmosis water through at least one filter membrane of a sterile filtration unit 11, wherein the filter membrane is preferably made of a material from the group consisting of polyethersulfone, PES, polyvinylidene fluoride, PVDF, cellulose acetate or nylon.

[0041] Fig. Figure 3 shows an exemplary schematic flowchart of a process for producing sterile water using the water treatment system according to the invention, in combination with corresponding cleaning and sterilization steps, according to a preferred embodiment of the invention. In particular, the temporal arrangement of the cleaning and testing steps of the membrane modules 12, 14 is shown schematically. The illustrated sequence begins with a step S1 of cleaning the water treatment system 2 by a CIP cleaning unit, followed by a step S2 of sterilizing the water treatment system 2 by a SIP sterilization unit, and a subsequent step S2.1 of filtering a supply gas by a sterile gas filtration unit. This is followed by a step S3 of performing an integrity test of the at least one filter membrane, in particular of the first membrane module 12 and the second membrane module 14, by the leak detection unit.If the integrity test is determined to be passed, the water treatment system 2 goes into the aforementioned in . Fig.Step 2, described above, involves the production of sterile water (S0) or switching to production mode. After completion of step S4 of the production process / cycle, the water treatment system is rinsed with purified water (S5), followed by cleaning (S6) of the water treatment system 2 by the CIP cleaning unit, sterilization (S7) of the water treatment system 2 by the SIP sterilization unit, and filtration (S7.1) of a supply gas by a sterile gas filtration unit. Subsequently, an integrity test of the filter membranes, specifically the first membrane module 12 and the second membrane module 14, is performed (S8) by the leak detection unit. Optionally, the supply tank is refilled with supply gas, specifically compressed air or nitrogen, simultaneously with the integrity test (S8).Subsequently (after an unspecified period), the time elapsed since the last step, S8, of the filter membrane integrity check is determined. If a new production cycle occurs within, for example, 48 hours after step S8 of the filter membrane integrity check, a new production cycle can be started directly, meaning the process proceeds directly to step S0 of producing sterile water. Otherwise, an additional intermediate step is performed: the (initial) steps S1 of cleaning water treatment system 2 by the CIP cleaning unit, followed by step S2 of sterilizing water treatment system 2 by the SIP sterilization unit, and finally step S2 of filtering.Step 1 of a supply gas passes through a sterile gas filtration unit, and step S3 involves performing an integrity test of at least one filter membrane. In this case, the present procedure skips from step S8 to the (initial) step S1. Thus, the entire cycle begins again. In any case, an integrity test of the filter membranes is performed before the start of a new production cycle (i.e., step S0). Reference symbol list 2 Water treatment system 4 aseptic filling systems 6 Reverse osmosis water tank 8 Pre-filtration unit 10 UV disinfection units 11 Sterile filtration unit 12 first membrane module 14 second membrane module 16 first aseptic tank 18 UHT device 20 second aseptic tank 22 mixing containers 24 In-line mixing device 26 Mixing device 28 carbonizers 30 Filling device Step 0: Preparing the sterile water S0.1 Step Pre-filtering the reverse osmosis water S0.2 Step Disinfecting the reverse osmosis water Step S0.3 Filtering the reverse osmosis water S1, S6 steps Cleaning the water treatment system by the CIP cleaning unit S2, S7 steps Sterilizing the water treatment system using the SIP sterilization unit S2.1, S7.1 Steps Filtering a supply gas through the sterile gas filtration unit S3, S8 steps: Performing an integrity check of at least one filter membrane Step S4: Ending the manufacturing process Step S5: Flushing the water treatment system with purified water

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