Preparation of medical water

Abstract

An operable apparatus for preparing medical water based on a supply water (W1), such as tap water. The apparatus comprises a filter device (21) and an irradiation device (22) connected in series to sequentially treat the feed water (W1) to generate dechlorinated water (W1 '). The filtration device (21) and the irradiation device (22) are in a redundant relationship with each other in that both are configured to effectively remove chlorine from the feed water, where the filtration device (21) achieves said effective removal by the use of one or more activated carbon filters and the irradiation device (22) is irradiated by ultraviolet (UV). Combining different removal techniques in a redundant manner slows down the need for intermittent sampling and analysis of water downstream of the filtration device (21). Furthermore, the operating condition of the filter device (21) and / or of the irradiation device (22) can be monitored by means of the irradiation device (22) in order to detect a fault.

Description

Technical Field

[0001] The present disclosure generally relates to the medical field, and particularly to a technique for removing chlorine from water supply to produce medical water. Background Art

[0002] Water can be used to produce medical fluids for medical use. The production of medical fluids can be carried out centrally or at the bedside. The water must meet the strict requirements set by standards or guidelines in terms of sterility and the content of potentially harmful substances. Water can be produced from tap water by a dedicated water preparation device having a purification device that operates by reverse osmosis and / or ion exchange. Such a purification device is highly sensitive to chlorine that is usually present in tap water. Therefore, the water preparation device can include a pretreatment stage for removing chlorine from the influent water by activated carbon filtration. To mitigate the so-called channeling risk, where the influent water passes through the activated carbon without sufficient dechlorination, the water preparation device can include two mutually redundant carbon beds connected in series to receive the influent water. By redundancy, each carbon bed is individually configured to achieve sufficient dechlorination of the influent water. Using a dual carbon bed requires frequent manual testing of the filtered water between the carbon beds to ensure that the redundancy is maintained, thus safeguarding the health of patients and downstream equipment. The testing is costly and time-consuming, involving manual handling of water samples. Currently, there is no device capable of automatically and cost-effectively measuring chlorine in water. Summary of the Invention

[0003] US2013 / 0126430 discloses a water purification system in which source water passes through one or more carbon block filters to remove chlorine and chloramine compounds. A UV device is arranged downstream of the carbon block filter to irradiate the water by UV radiation to ensure the sterility of the water. It is understood that US2013 / 0126430 also proposes replacing the UV device with a carbon block filter configured to achieve dechlorination and sterilization of the source water.

[0004] An object of the present application is to at least partially overcome one or more limitations of the prior art.

[0005] An object of the present application is to reduce the need for manual measurement of the chlorine content of water during the operation of a device for preparing medical water.

[0006] One or more of these objects and other objects that may arise from the following description are at least partially achieved by a device for preparing water, a system, and a method for preparing water according to the independent claims, the embodiments of which are defined by the dependent claims.

[0007] A first aspect is a water treatment device for water used in the medical treatment of humans or animals. The device is configured to receive a water supply from a water source. The device includes: a filtration device configured to effectively remove chlorine from the water supply by using one or more activated carbon filters; and an irradiation device configured to effectively remove chlorine from the water supply by ultraviolet (UV) irradiation. The filtration device and the irradiation device are connected in series to sequentially process the water supply into dechlorinated water. The device is configured to provide conditioned water for medical use based on the dechlorinated water.

[0008] In some embodiments, the irradiation device includes a housing that defines a treatment chamber, an inlet to the treatment chamber for incoming water, and an outlet from the treatment chamber for outgoing water, and the irradiation device further includes at least one UV radiation source arranged to irradiate at least a portion of the treatment chamber.

[0009] In some embodiments, the irradiation device further includes at least one sensor arranged to generate a measurement signal indicative of the UV radiation intensity in the treatment chamber, and the device further includes a control device configured to receive the measurement signal and monitor the operation of at least one of the filtration device and the irradiation device based on the measurement signal.

[0010] In some embodiments, the control device is configured to evaluate the relationship between the UV radiation intensity in the treatment chamber and an intensity limit based on the measurement signal, and generate an alarm indicative of a failure of the irradiation device when the UV radiation intensity drops below the intensity limit.

[0011] In some embodiments, the failure includes at least one of a reduction in the radiation power of at least one UV radiation source or fouling in the treatment chamber.

[0012] In some embodiments, the intensity limit corresponds to the irradiation device being operable to effectively remove chlorine from the water supply.

[0013] In some embodiments, at least one UV radiation source includes a light-emitting diode or a laser diode.

[0014] In some embodiments, at least one UV radiation source includes a first radiation-emitting element and a second radiation-emitting element, wherein the first and second radiation-emitting elements are configured to emit UV radiation in different wavelength ranges.

[0015] In some embodiments, the control device is configured to activate the first radiation-emitting element, the second radiation-emitting element, or both the first and second radiation-emitting elements to remove chlorine from the water supply.

[0016] In some embodiments, the control device is configured to selectively activate at least one of the first or second radiation-emitting elements based on input data representative of the chlorine composition in the water supply.

[0017] In some embodiments, the first radiation emitting element is configured to preferentially remove monochloramine rather than free chlorine and dichloramine, and the second emitting element is configured to preferentially remove free chlorine and dichloramine rather than monochloramine.

[0018] In some embodiments, the first radiation emitting element is configured to generate UV radiation having a peak within a first wavelength range of 240 - 265 nm, and the second emitting element is configured to generate UV radiation having a peak within a second wavelength range of 265 - 290 nm.

[0019] In some embodiments, at least one UV radiation source is configured to generate UV radiation within a wavelength range of 100 - 400 nm and preferably within a wavelength range of 200 - 325 nm.

[0020] In some embodiments, the irradiation device is configured to operate with water flowing continuously through the treatment chamber from an inlet to an outlet.

[0021] In some embodiments, the control device is configured to detect channel formation in one or more activated carbon filters of the filtration device based on a measurement signal; and to generate an alarm signal when channel formation is detected.

[0022] In some embodiments, the control device for said channel formation detection is configured to evaluate the measurement signal to detect a decrease in a step change in the measurement signal.

[0023] In some embodiments, the control device is configured to detect a decrease in a step change by comparing the signal level in the measurement signal with a threshold.

[0024] In some embodiments, the control device is configured to determine a reference level at a current time point based on a previous signal value in the measurement signal; set a threshold related to the reference level; and compare the signal level in the measurement signal at the current time point with the threshold.

[0025] In some embodiments, the irradiation device includes another UV radiation source and another sensor, which are arranged downstream of said at least one source and said sensor, and the other sensor is arranged to generate another measurement signal indicative of the intensity of the UV radiation received from the other source, and the control device is configured to detect channel formation based on the measurement signal and the other measurement signal.

[0026] In some embodiments, the control device for said channel formation detection is configured to evaluate the other measurement signal to detect another decrease in a step change in the other measurement signal.

[0027] In some embodiments, the control device is configured to generate an alarm signal when it detects that another step change decrease in another measurement signal is temporally synchronized with a corresponding step change decrease in the measurement signal.

[0028] In some embodiments, the filtering device is arranged upstream of the irradiation device.

[0029] In some embodiments, the filtering device and the irradiation device are included in a pretreatment subsystem, and the device further includes a main subsystem that is arranged to receive dechlorinated water from the pretreatment subsystem and is configured to process the dechlorinated water to produce conditioned water.

[0030] In some embodiments, the main subsystem includes at least one of a reverse osmosis device or an ion exchange device.

[0031] In some embodiments, the filtering device and the irradiation device are connected in series without an intermediate treatment device for removing chlorine.

[0032] In some embodiments, the device is configured to supply the conditioned water to a dialysis machine.

[0033] In some embodiments, the filtering device includes a single activated carbon filter that is configured to effectively remove chlorine from the water supply.

[0034] In some embodiments, the irradiation device is configured to remove a first target amount of chlorine from the water supply, the filtering device is configured to remove a second target amount of chlorine from the water supply, and the second target amount is at least equal to the first target amount and less than twice the first target amount.

[0035] A second aspect is a system that includes a device for preparing water according to the first aspect or any of its embodiments, and a dialysis machine that is fluidly connected to receive the conditioned water from the device for preparing water.

[0036] A third aspect is a method of preparing water for medical use in a human or animal body. The method includes: receiving a water supply from a water source; and operating a filtering device and an irradiation device connected in series to sequentially process the water supply into dechlorinated water, where the filtering device is configured to effectively remove chlorine from the water supply by activated carbon filtration, and where the irradiation device is configured to effectively remove chlorine from the water supply by ultraviolet (UV) irradiation. The method further includes providing conditioned water for medical use based on the dechlorinated water.

[0037] Embodiments of the first aspect may be adapted to be embodiments of the third aspect.

[0038] Other objectives, aspects, embodiments, technical effects, as well as features and advantages can be seen from the following detailed description, the appended claims, and the drawings.

[0039] Brief Description of the Drawings

[0040] Figures 1A to 1B is a schematic diagram of an exemplary system for dialysis treatment, and Figure 1C is for Figures 1A to 1B a block diagram of an exemplary water treatment device in the system of

[0041] Figure 2 is an example of a reference subsystem for removing chlorine from water by activated carbon filtration.

[0042] Figure 3 is a block diagram of an exemplary dechlorination subsystem in a water treatment device according to an embodiment.

[0043] Figures 4A to 4B is according to an embodiment of Figure 3 a cross-sectional view of an irradiation device and a filtration device in the dechlorination subsystem of

[0044] Figure 5 is a graph of the absorption spectra of two kinds of chloramines, with the emission spectra of three exemplary UV-LEDs superimposed.

[0045] Figure 6A is Figure 3 a flowchart of an exemplary configuration process of the dechlorination subsystem in Figures 6B to 6D and is a flowchart of an exemplary process for operating a water treatment device according to an embodiment.

[0046] Figure 7 is a schematic diagram of an exemplary main subsystem in a water treatment device.

[0047] Figures 8A to 8B is a graph of experimental results related to dechlorination by UV radiation.

[0048] Figure 9A shows a first irradiation device, and Figure 9B is a graph of exemplary signals from the first irradiation device during channeling in an upstream filtration device.

[0049] Figure 10A shows a second irradiation device, and Figure 10B is a graph of exemplary signals from the second irradiation device during channeling in an upstream filtration device. Detailed Description of the Invention

[0051] Embodiments will now be described more fully hereinafter with reference to the accompanying drawings, in which some but not all embodiments are shown. In fact, the subject matter of the present disclosure may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure may satisfy applicable legal requirements.

[0052] In addition, it should be understood that, to the extent possible, any advantages, features, functions, devices, and / or operational aspects of any embodiment described and / or contemplated herein can be included in any other embodiment described or contemplated herein, and vice versa. Further, to the extent possible, unless otherwise expressly stated, any term expressed in the singular herein also means including the plural, and vice versa. As used herein, "at least one" shall mean "one or more," and these phrases are intended to be used interchangeably. Thus, the terms "a" and / or "an" shall mean "at least one" or "one or more," even though the phrases "one or more" or "at least one" are also used herein. As used herein, unless the context requires otherwise due to the language of expression or necessary meaning, the word "comprise" or variations such as "comprises" or "comprising" are used in an inclusive sense, i.e., specifying the presence of the stated feature, but not precluding the presence or addition of other features in various embodiments.

[0053] As used herein, the terms "plural," "plurality," and "majority" are intended to imply the provision of two or more elements. The term "and / or" includes any and all combinations of one or more of the associated listed elements.

[0054] Furthermore, it should also be understood that although terms such as first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of the present disclosure, the first element may be referred to as the second element, and similarly, the second element may be referred to as the first element.

[0055] For the sake of brevity and / or clarity, well-known functions or constructions may not be described in detail. Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains.

[0056] The same reference signs always refer to the same elements.

[0057] The present disclosure relates to a technology for preparing water for medical treatment of the human or animal body. As used herein, medical treatment is an attempt to remedy a health problem and includes any therapy that brings water into contact with the body. The present disclosure may be particularly relevant to current or future therapies in which water is mixed with one or more concentrates either centrally in a clinic or at the bedside by a machine to form a medical fluid that permits interaction with the patient's blood. Such therapies include dialysis treatment, plasmapheresis, apheresis, extracorporeal membrane oxygenation, assisted blood circulation, extracorporeal liver support / dialysis, and the like. It is foreseeable that such "on-demand generation" of medical fluids will become increasingly common in the future. On-demand generation allows for the production of medical fluids in the desired amounts and also allows for adjustment of the composition of the medical fluids. Traditionally, prefabricated medical fluids are shipped to clinics in containers or bags. On-demand generation reduces the need to store and handle prefabricated medical fluids in clinics.

[0058] As previously mentioned, the water preparation technology is applicable to dialysis treatment.

[0059] As used herein, "dialysis treatment" refers to any therapy that uses dialysate to replace or supplement the kidney function of a patient. Dialysis treatment includes, but is not limited to, extracorporeal (EC) blood treatment and peritoneal dialysis (PD) treatment. Examples of EC blood treatment include hemodialysis (HD), hemofiltration (HF), and hemodiafiltration (HDF). For reference only, fluid generation related to EC blood treatment and PD treatment will be briefly discussed. Figures 1A to 1B Brief discussion will be made on fluid generation related to EC blood treatment and PD treatment.

[0060] Figure 1AGeneral overview of a system for EC blood treatment. The system includes a water preparation apparatus (WPA) 20 and a dialyzer 30. The WPA 20 is connected via a first fluid line 41 to receive an input water supply W1 from a water source 10. The water supply W1 can be tap water (drinking water) or some form of pretreated tap water. The WPA 20 is configured to treat W1 into conditioned water W2, which has sufficient quality for EC blood treatment and is commonly referred to as "dialysis water" (for preparing dialysate, ultrapure dialysate, and on-line prepared replacement fluid). The quality of W2 is given by standards or guidelines, such as ANSI / AAMI / ISO23500-3:2019. The dialyzer 30 is connected via a second fluid line 42 to receive W2 from the WPA 20. The dialyzer 30 is configured to mix W2 with one or more concentrates to produce a treatment fluid for EC blood treatment, such as dialysate and / or replacement fluid. The dialyzer 30 is fluidly connected to the vascular system of a patient P in a fluid path. In the example shown, the fluid path is defined by a conduit 43 for blood extraction and a conduit 44 for blood return. As indicated by the arrows, the dialyzer 30 is operable to withdraw blood from the patient P via the conduit 43, treat the blood, and return the treated blood to the patient via the conduit 44. The conduits 43, 44 are connected to an access device (e.g., a catheter, cannula, or fistula, not shown) that is in fluid communication with the vascular system of the patient P. The dialyzer 30 can be configured to treat the blood by using the treatment fluid. For example, the dialysate can be conjugated with the blood in a dialyzer and / or replacement fluid can be added to the blood, as is well known in the art.

[0061] Figure 1B General overview of a system for PD treatment. As Figure 1A shown, the system includes a WPA 20, which is configured to produce conditioned water W2 ("dialysis water" or "water for injection") from the water supply W1 received from the water source 10. The quality of W2 can be given by standards or guidelines for PD treatment. The dialyzer 30 is fluidly connected to the peritoneal cavity PC of a patient P. The dialyzer 30 is configured to mix W2 with one or more concentrates to produce a treatment fluid for PD treatment. As indicated by the double-headed arrow, the dialyzer 30 is operable to deliver fresh treatment fluid into the peritoneal cavity PC and receive spent treatment fluid from the PC in a fluid path 43. The fluid path 43 can be defined by a conduit connected to an implanted catheter (not shown) that is in fluid communication with the PC. The dialyzer 30 can be configured for any type of PD treatment and can include a dialysis machine ("cycler") that performs dialysis treatment, as is well known in the art.

[0062] Figure 1C General overview of the water preparation apparatus WPA, 20, which can be used for Figures 1A - 1Bsystems and other systems for medical use. The WPA 20 includes a pretreatment subsystem 20', which is connected to receive the water supply W1 on the fluid line 41. The subsystem 20' is configured for the process W1 of producing dechlorinated water W1'. The subsystem 20' is hereinafter referred to as the "dechlorination subsystem". The main subsystem 20" is connected to receive the dechlorinated water W1' from the dechlorination subsystem 20' on the connecting fluid line 20A. The main subsystem 20" is configured to perform final treatment on the dechlorinated water W1' to produce conditioned water W2, which is output on the fluid line 42. From the above, it can be understood that W2 is generated with acceptable quality and can be used for the intended medical treatment. In a non-limiting example applicable to "dialysis water", W2 meets the following maximum allowable levels of toxic chemicals: aluminum 0.01 ppm, copper 0.1 ppm, fluoride 0.2 ppm, lead 0.005 ppm, nitrate 2 ppm, sulfite 100 ppm, zinc 0.1 ppm, and total chlorine 0.1 ppm.

[0063] The WPA 20 is configured to perform the purification of W1. Water purification is the process of removing unwanted chemicals, biological contaminants, suspended solids, and gases from water. The main removal of impurities in W1 is performed by the main subsystem 20". These impurities include ions and organic contaminants. The main subsystem 20" typically includes one or more advanced purification devices, such as using membrane filtration or ion exchange, or a combination thereof. A commonly used water purification membrane filtration technique is reverse osmosis (RO), where the RO membrane is used to separate ions, molecules, and larger particles from water. Ion exchangers (IEX) are also commonly used in water purification. Simply put, an ion exchanger removes ionic impurities from water by replacing the corresponding ionic impurities with another ionic substance. Typical ion exchangers are ion exchange resins (functionalized porous or gel polymers), zeolites, montmorillonite, clay, or soil humus. Electro-deionization (EDI) is also used in water purification. In principle, any conventional or future water purification technology can be implemented in the main subsystem 20" according to the quality required for W2.

[0064] The dechlorination subsystem 20' is configured to effectively remove chlorine from the water supply W1. As used herein, "effective removal" means that the total amount of chlorine in the dechlorinated water W1' is about 0.1 mg / L (0.1 ppm) or lower.

[0065] Tap water may contain chlorine, often expressed as residual chlorine, because water chlorination is carried out at the water treatment plants where tap water is produced. Water chlorination is the process of adding chlorine or chlorine compounds such as hypochlorous acid to water, aiming to kill bacteria, viruses and other microorganisms in the water. In particular, chlorination is used to prevent the spread of waterborne diseases such as cholera, dysentery and typhoid. Residual chlorine refers to the amount of chlorine remaining in the water after a certain time or contact time (e.g., 30 minutes). In the United States, a total chlorine amount up to 4 mg / L (4 ppm) is considered safe for drinking water. The residual chlorine in chlorinated tap water may exist in free form and combined form. The free form may include dissolved hypochlorite ions, hypochlorous acid and chlorine gas. The combined form may include chloramines that kill bacteria and oxidize organic matter. Examples of such chloramines include monochloramine, dichloramine and trichloramine. The total amount of chlorine is given by the sum of free and combined chlorine.

[0066] One reason for installing the dechlorination subsystem 20' upstream of the main subsystem 20" is to protect the main subsystem 20", and by extension, to protect the patient. Many advanced purification devices are sensitive to the strong oxidizing property of chlorine. For example, the RO membrane in an RO device can be easily and irreversibly damaged by chlorine. Similarly, the ion exchanger in an ion exchange device may be irreversibly damaged by chlorine. Even if the main subsystem 20" should be chlorine-resistant, the dechlorination subsystem 20' can still be installed to reduce the operating requirements for the main subsystem 20". The dechlorination subsystem 20' needs to be configured to not only remove residual chlorine, but also reduce the amounts of particles, total dissolved solids (TDS), volatile organic compounds (VOC), trihalomethanes (THM), heavy metals, etc. in the water supply W1.

[0067] Figure 2 A reference example of the dechlorination subsystem 20' is shown, which operates by passing the water supply through a series of activated carbon (AC) filters 100. The reference example is given to facilitate the technology described below with reference to Figure 3 -6. In Figure 2In it, the inlet pipeline 101 is fluidly connected to the inlet of the first AC filter 100, the connecting pipeline 102 is fluidly connected to the outlet of the first AC filter 100 and the inlet of the second AC filter 100, and the outlet pipeline 103 is fluidly connected to the outlet of the second AC filter 100. Each AC filter 100 is formed by a container that houses activated carbon 100A (also known as activated charcoal or active charcoal). The activated carbon 100A has been processed (activated) to have small, low-volume pores that increase the surface area available for adsorption or chemical reactions. The activated carbon 100A forms a bed within the container. The activated carbon bed is arranged to remove chlorine from the influent water and to absorb toxic substances and pesticides. In one exemplary embodiment, the activated carbon bed is arranged to remove chlorine in free and combined forms. In another exemplary embodiment, the activated carbon bed is also arranged to reduce organic compounds (TOC, total organic carbon) in the influent water, including pesticides.

[0068] In the example shown, each AC filter 100 is configured individually to effectively remove chlorine from the water supply. Two AC filters 100 are used to introduce redundant filtration capacity to avoid irreparable damage to downstream equipment if one of the AC filters 100 fails. For example, a known problem with AC filters 100 is channeling. When water enters the AC filter 100, it automatically flows through the AC filter 100 along the path of least resistance, forming one or more channels through the activated carbon 100A. Channeling can result in insufficient chlorine removal by the AC filter 100. The AC filter 100 also deteriorates with use, resulting in a decrease in performance over time. In this reference example, early detection of failure is crucial. Therefore, the chlorine content of the water passing through the connecting pipeline 102 is regularly tested for an increase. In the example shown, a bypass pipeline 104 that includes an on / off valve 105 extends from the connecting pipeline 102 to a sampling port 106. A water sample is taken at the sampling port 106 by opening the on / off valve 105, and the chlorine content of the sample is measured using a dedicated measuring device (such as a spectrometer, spectrophotometer, or colorimeter). If an increase in chlorine content is detected in the sample, the first AC filter 100 is discarded and replaced with a new AC filter 100. Typically, samples are taken and analyzed at the start of each day before the first patient of the day is treated. Then, sampling and analysis can be repeated every 4 hours either before connecting a new patient or during WPA 20 operation. This procedure is both time-consuming and costly. The analysis requires specialized and expensive equipment. Sampling is labor-intensive. Samples may need to be transported to the central laboratory of the clinic for analysis. Processing test data from multiple WPAs 20 requires management routines to minimize errors.

[0069] The Applicant has found that by using a new concept involving the combination of AC filtration and ultraviolet (UV) radiation irradiation, this cumbersome test scope can be avoided or at least reduced. Specifically, AC filtration and UV irradiation are performed sequentially, where each of AC filtration and UV irradiation is sufficient to effectively remove chlorine from the water supply W1. Therefore, compared with AC filtration, UV irradiation is redundant. Thus, similar to the second (downstream) AC filter 100 in the subsystem 20' of Figure 2 , UV irradiation is redundant, with the important difference being that UV irradiation is monitorable. AC filtration is a passive, purely mechanical process, and its performance can only be evaluated through water tests. On the other hand, UV irradiation is an active process involving the generation of UV radiation. The execution of UV irradiation can be monitored by the generated UV radiation.

[0070] Figure 3 An example of a dechlorination subsystem 20' for WPA 20 according to the above concept is shown. The subsystem 20' receives the water supply W1 on the input pipeline 41 and outputs the dechlorinated water W1' on the connecting fluid pipeline 20A for the main subsystem 20" to receive ( Figure 1C ). The subsystem 20' includes a filtering device 21 and an irradiation device 22 connected in series to sequentially process the water supply W1 into dechlorinated water W1'. In the example shown, the filtering device 21 is arranged upstream of the irradiation device 22 to receive and process the water supply W1. The filtering device 21 includes a filtering module 21A, which is configured to effectively remove chlorine from W1 through activated carbon filtration. Thus, the processing of the filtering device 21 produces dechlorinated water, which is referred to as "intermediate water" and denoted as W1". The connecting fluid pipeline 20B extends between the filtering device 21 and the irradiation device 22 to convey W1" to the irradiation device 22. The irradiation device 22 includes an irradiation module 22A, which is configured to effectively remove chlorine from W1 through UV irradiation. The irradiation device 21 operates on W1" and outputs dechlorinated water W1'.

[0071] Since the filtering device 21 and the irradiation device 22 in the subsystem 20' are redundant with each other in terms of dechlorination, as long as the filtering device 21 is working properly, the intermediate water W1" will be sufficiently dechlorinated. Therefore, during the normal operation of the filtering device 21, the dechlorinated water W1' generated by the irradiation device 22 may not be distinguishable from the intermediate water W1". However, it is conceivable that the irradiation device 22 causes further dechlorination of the intermediate water W1", so that the subsystem 20' reduces the total chlorine content to a level far lower than that required by the main subsystem 21'.

[0072] It should be appreciated that the filtration device 21 and / or the irradiation device 22 may include additional components such as pumps, valves, sensors, tanks, etc. In the illustrated example, it is assumed that the filtration device 21 is operable to generate one or more measurement signals S1 and receive one or more control signals C1 to control its operation. In some implementations, S1 and / or C1 may be omitted. The irradiation device 22 is operable to generate at least one measurement signal S2 and receive one or more control signals C2 to control its operation.

[0073] Since the filtration device 21 and the irradiation device 22 are separately configured to effectively remove chlorine from the influent water, no additional equipment is required in the dechlorination subsystem 20' to remove chlorine. For example, along the water flow path between the filtration device 21 and the irradiation device 22, there is typically no intervening equipment for removing chlorine.

[0074] In an alternative embodiment (not shown), the irradiation device 22 is installed upstream of the filtration device 21. Thus, the reclaimed water W1” is instead generated by the irradiation device 22 from the supply water W1 and is delivered to the filtration device 21 through the connecting fluid line 20B, which generates the dechlorinated water W1’ from the reclaimed water W1”.

[0075] It is currently considered beneficial to arrange the filtration device 21 upstream of the irradiation device 22, as Figure 3 shown. As is well known, an activated carbon bed is a nutrient-rich environment for microorganisms and can be considered a key point for microorganisms to enter the rest of the fluid circuit. As is well known, UV irradiation reduces microbial activity. Therefore, by placing the irradiation device 22 downstream of the filtration device 21, the microbial load ( Figure 1C ) entering the main subsystem 20” can be reduced. This will protect the health of the patient and also extend the lifespan of the downstream components in the WPA 20. In addition, the filtration device 21 can reduce the amount of suspended solids in the water entering the irradiation device 22. Suspended solids may impair the performance of the irradiation device 22, for example, by absorbing or deflecting UV radiation or by fouling the irradiation device 22.

[0076] Alternatively or additionally, the presence of suspended solids can be mitigated by including a particle filter upstream of the irradiation device 22 for removing particles such as clay, silt, and silica. The particle filter can be a sediment filter and can be configured to filter out micron-sized particles, as well as optionally large endotoxin molecules, from the influent water.

[0077] Providing a dedicated particle filter may be particularly important if the irradiation device 22 is arranged upstream of the filtration device 21.

[0078] In some embodiments, the particle filter is integrated into the filtration device 21.

[0079] The control device 50 is configured to implement the logic for controlling the dechlorination system 20' and optionally the primary subsystem 20". Figure 1C ) In the illustrated example, the control device 50 is configured to generate control signals C1, C2 at least in part based on the sensor signals S1, S2. The control device 50 includes a combination of a processing circuit 51 and a memory 52. The memory 52 may store program instructions for execution by the processing circuit 51 to implement the operation of the control device 50. The control device 50 includes a signal interface 53A for inputting the sensor signals S1, S2 and outputting the control signals C1, C2. In the illustrated example, the control device 50 further includes a signal interface 53B for receiving input data from an input device 54 (e.g., keyboard, mouse, microphone, touch screen, etc.) and providing output data to a feedback device 55 (e.g., display, speaker, projector, etc.). The above program instructions may be provided to the control device 50 on a computer-readable medium, which may be a tangible (non-transitory) product (e.g., magnetic medium, optical disc, read-only memory, flash memory, etc.) or a propagated signal. The processing circuit may include a general-purpose processor, such as a microprocessor, a microcontroller, a CPU, a DSP (digital signal processor), a GPU (graphics processing unit), etc., or a dedicated processor, such as an ASIC (application-specific integrated circuit) or an FPGA (field-programmable gate array), or any combination thereof. The memory 52 may include volatile and / or non-volatile memory, such as read-only memory (ROM), random access memory (RAM), or flash memory.

[0080] Figure 4A is for Figure 3 A cross-sectional view of an exemplary irradiation module 22A of the dechlorination device 20' for... The module 22A includes a housing or casing 220 that defines a processing chamber 221 having one or more inlets or inlet ports 222 (one shown) and one or more outlets or outlet ports 223 (one shown). The influent water enters the processing chamber 221 through the inlet 222, and the effluent water leaves the processing chamber 221 through the outlet 223. In the context of... Figure 3 ... the inlet 222 is connected to receive the reclaimed water W1" from the connecting fluid line 20B, and the outlet 223 is connected to supply the dechlorinated water W1' to the connecting fluid line 20A. At least one UV radiation source 224 (one shown) is disposed in the processing chamber 221. The UV source 224 is operable to generate UV radiation to irradiate at least a portion of the processing chamber 221 by a divergent light beam, as Figure 4AAs shown by the dashed line in []. The UV radiation thus interacts with the fluid within the processing chamber 221. The UV source 224 can include any element capable of generating UV radiation, including but not limited to light-emitting diodes (LEDs), laser diodes, fluorescent lamps, incandescent lamps, gas discharge lamps, etc. To reduce power consumption and cost, the UV source 224 can include one or more LEDs or laser diodes. LEDs and laser diodes also have the characteristics of small footprint, long service life, and clear emission spectrum. At least one UV sensor 225 (one shown) is arranged to generate a measurement signal S2 indicative of the intensity of the UV radiation in the processing chamber 221. The signal value in the signal S2 can be given in any suitable unit, such as a voltage indicative of the incident power or irradiance on the UV sensor 225. In the context of this specification, the measured intensity value can be given in the unit provided by the UV sensor 225, or in any other unit given by applying a conversion function to the signal value from the UV sensor 225. The UV sensor 225 can include any element responsive to UV radiation, including but not limited to photodiodes, phototransistors, photoconductive detectors, phototubes, photocells, etc. The UV sensor 225 can be arranged at any position irradiated directly or indirectly by the UV source 224. In the illustrated example, the UV sensor 225 is arranged opposite to the UV source 224. In other examples, the UV sensor 225 is arranged on the same side as the UV source 224, or even physically integrated with the UV source 244 into a package.

[0081] The irradiation module 22A can be configured for continuous or batch processing. In batch processing, water intermittently enters the chamber 221 for treatment. In continuous processing, water is continuously conveyed through the chamber 221 while being treated. Continuous processing may require a greater emission (radiation) power of the UV source 224, but may increase the productivity of preparing the conditioned water W2 by the WPA 20.

[0082] The UV source 224 can be configured to generate UV radiation in the wavelength range of 100 - 400 nm. The UV radiation is significantly absorbed by water molecules below 200 nm, while the bound forms of chlorine have a lower absorption of UV radiation above approximately 350 nm. Thus, the UV source 224 can be configured to limit the generated UV radiation within the range of 200 - 350 nm. In some embodiments, the generated UV radiation is limited within the range of 200 - 280 nm.

[0083] Figure 5 is a graph of the molar extinction coefficients 501 of dichloramine (NHCl2) and 502 of monochloramine (NH2Cl) as a function of wavelength. The molar extinction coefficient curves 501, 502 approximately correspond to the photolytic decomposition of the respective substances as a function of wavelength. At Figure 5In it, dichloramine (curve 501) has an elevated absorption coefficient in the range of 275 - 315 nm, with a local maximum at approximately 295 nm, while monochloramine (curve 502) has an elevated absorption coefficient in the range of approximately 225 - 275 nm, with a local maximum at approximately 245 nm. It may be desirable to match the emission spectrum of the UV source 224 with Figure 5 the regions of elevated absorption coefficient in it to optimize the chlorine reduction efficiency of the module 22A. Three exemplary emission spectra R1, R2, R3 of the UV source 224 are shown by dashed lines in Figure 5 it. Spectrum R1 approximately matches the local maximum of curve 502 at approximately 245 nm and may result in the maximum photolysis of monochloramine. Spectrum R2 approximately matches the local maximum of curve 501 at approximately 295 nm and may result in the maximum photolysis of dichloramine. Spectrum R3 approximately matches the intersection point of curves 501 and 502 at approximately 270 nm.

[0084] The choice of wavelength can also account for the absorption coefficient curves of dissolved hypochlorite ions and hypochlorous acid, which may be included in the influent water in the form of free chlorine. According to the literature data, both of these substances have a relatively wide range of elevated absorption coefficients: the absorption coefficient range of hypochlorous acid is approximately 220 - 255 nm, with a local maximum at approximately 240 nm, and the absorption coefficient range of dissolved hypochlorite ions is 265 - 320 nm, with a local maximum at approximately 290 nm.

[0085] Depending on the emission characteristics of the available UV emission elements, it may be advantageous to combine at least two UV emission elements with different emission spectra in the UV source 224. The emission spectra of different UV emission elements may or may not overlap. In some embodiments, the UV emission elements are configured to emit in different wavelength ranges, which may or may not partially overlap. In Figure 4A the example of, the UV source 224 includes three radiation emission elements L1, L2, L3, such as UV-LEDs, which are configured to generate emission spectra R1, R2, and R3 respectively in Figure 5 it. In some embodiments, the corresponding UV emission elements are configured to generate emission spectra (see R1, R2, R3 in Figure 5 it), the approximate width (full width at half maximum, FWHM) of which is in the range of 5 - 15 nm.

[0086] The irradiation module 24A can be designed to supply water W1 with a specific total chlorine composition by adjusting the UV source 225. For example, in certain regions, the supply water W1 contains a low concentration of dichloramine. In addition, there may be significant differences in the total chlorine content in different regions. Therefore, the UV source 225 can be selected to have suitable emission characteristics for a specific region, such as in terms of output (radiation) power, wavelength of UV radiation, etc.

[0087] As described above, the irradiation module 22A may include a UV source 224 having two or more UV-emitting elements configured to emit UV radiation in at least partially different wavelength ranges, where the wavelength ranges may be selected to target the decomposition of different chlorine species in the water to be dechlorinated. In some embodiments, at least one UV-emitting element is configured to primarily cause the decomposition of monochloramine, and at least one UV-emitting element is arranged to primarily cause the decomposition of free chlorine and dichloramine. This allows for the optimization of the UV radiation from the UV source 224. In some embodiments, this is achieved by the combined use of UV-emitting elements that emit in the ranges of 240 - 265 nm and 265 - 290 nm, respectively.

[0088] In some embodiments, the irradiation module 22A may be operated to selectively activate one or more of the UV-emitting elements in the UV source 224 based on the expected composition of the total chlorine in the water supply W1 to be dechlorinated. In some embodiments, the control device 50 will automatically and selectively activate one or more of the available UV-emitting elements in the UV source 224 based on the content data of the water supply (see step 601). The content data is available to the control device 50 to indicate the composition of chlorine in the water supply.

[0089] UV irradiation is currently used as a disinfection method for drinking water treatment. The underlying mechanism is that the nucleic acids in microorganisms are damaged after absorbing the incident UV radiation. The present applicant has conducted experiments showing that in a conventional device configured for water disinfection by UV irradiation, the radiation (emission) power of the UV source needs to be increased by at least 10 times, possibly at least 15 times or 20 times, to decompose the chlorine in the water.

[0090] Figure 3 The filter module 21A in the dechlorination subsystem 20' can be configured as shown. However, since the irradiation module 22A provides redundancy related to the filter module 21A, it may be considered to remove or at least reduce the internal redundancy of the filter module 21A. Thus, in some embodiments, the internal redundancy of the filter module 21A is less than 2, for example, in the range of 1.0 - 1.9, where an internal redundancy of 1.0 or 1.9 means that the filter module 21A is designed to remove 100% or 190% of the target amount of total chlorine, respectively (see step 610 below). Figure 2

[0091] Figure 2 The removal or reduction of redundancy can be achieved by removing one of the AC filters 100, or by reducing Figure 2 ​​implemented by the filtering capacity of the corresponding AC filter 100 therein, for example, by using an AC filter 100 containing a relatively small amount of activated carbon 100A. This will reduce the manufacturing cost and operating cost of the filtering device 21, thereby offsetting the additional cost of the irradiation device 22. Currently, it is considered that the cost of the irradiation module 22A is comparable to the cost of the conventional AC filter 100. Considering that the AC filter in the reference example is usually replaced 2-3 times a year, while the service life of the irradiation module 22A may be several years, compared with Figure 2 the reference example in, the new concept can actually save a considerable amount of cost.

[0092] Figure 4B shows an example of a filter module 21A having a single AC filter 100, which AC filter includes an activated carbon bed 100A. The inlet line 101 is fluidly connected to the inlet of the AC filter 100, and the outlet line 102 is fluidly connected to the outlet of the AC filter 100. In the example shown, the supply water W1 passes through the AC filter 100 to produce reclaimed water W1” (see Figure 3 ).

[0093] Figure 6A is a flowchart of an example method 600 for configuring the dechlorination subsystem 20’ according to an embodiment. The method 600 can be performed by a technician before deploying the subsystem 20’ or when designing the subsystem 20’. In step 601, the expected amount (“design amount”) of total chlorine in the supply water W1 is obtained. The design amount can be given by measurement or by nominal data. Step 601 can involve obtaining detailed content data on the chlorine content in the supply water, such as the relationship between the free form and the combined form, or the composition of the free form and / or the combined form. In step 602, the target amount of total chlorine to be removed from the supply water is determined based on the design amount, for example, to meet the predetermined requirements of the dechlorinated water W1’. In step 603, the filtering device 21 is configured to eliminate the target amount by using activated carbon filtration. For example, the amount of activated carbon 100A can be selected or the flow rate of the supply water W1 can be adjusted according to the target amount and the internal redundancy selected for the filtering device 21. In step 604, the irradiation device 22 is configured to eliminate the target amount by UV irradiation. For example, step 604 can involve adjusting, according to the target amount, for example, the number of UV sources 224, the radiation power, the emission spectrum of the UV sources 224, the size of the chamber 221, etc. In one example, a technician selects a suitable irradiation module 22A from a plurality of different irradiation modules 22A to be installed in the irradiation device 22. Alternatively, if a single pre-configured irradiation module 22A is available, the technician can adjust the radiation power of the UV source 225 according to the target amount. Those skilled in the art understand that the irradiation device 22A can also be configured according to the above detailed content data.

[0094] Figure 6B is Figure 3Flowchart of an example process 610 for operating the WPA 20. The program 610 can be executed by the control device 50( Figure 3 ). In step 611, the water supply W1 is allowed to enter the WPA 20. In step 612, the filtration device 21 is operated according to predefined settings to pass the water supply through the activated carbon in the filter module 21A. The predefined settings can be given by step 603 of the method 600. In step 613, the irradiation device 22 is operated according to predefined settings to receive the reclaimed water W1” from the filtration device 21 and irradiate W1” with UV radiation. The predefined settings can be given by step 604 of the method 600. In step 614, the main subsystem 20” is operated according to predefined settings to receive the dechlorinated water W1’ and process it into the conditioned water W2. Thus, the result of step 614 is the preparation of W2 based on W1’. Step 614 can be performed according to conventional practices, depending on the type of water purification equipment in the main subsystem 20”. In step 615, the conditioned water W2 is provided for medical use. The conditioned water W2 can be provided as a continuous flow or in batches from the WPA 20.

[0095] It can be noted that, in addition to the other advantages described herein, the irradiation device 22 will also prevent the “chlorine spike” in the chlorine concentration of the water supply W1 from affecting the dechlorinated water W1”. In some regions, it is not uncommon for the total chlorine in the water supply W1 to exceed the designed amount (see step 601), for example, because of the instability of the water treatment plant that produces W1. During a chlorine spike, the intermittent water W1” may contain an elevated chlorine concentration, which will be reduced to an acceptable level by the irradiation device 22.

[0096] The applicant has found that the status of the irradiation device 22 can thus be monitored based on the measurement signal S2( Figure 3 and Figure 4A ). Experiments have shown that the signal S2 is related to the radiation power of the UV source. Experiments have also shown that the signal S2 is affected by the status of the chamber 221. For example, deposits on the UV source 224 and the UV sensor 225 in the chamber 221 may reduce the signal S2. Therefore, the control device 50 can operate based on the signal S2 to detect whether maintenance of the irradiation device 22 is required.

[0097] Figure 6C is an example method 620 for monitoring the operating status of the irradiation device 22 according to an embodiment. The method 610 can be executed by the control device 50( Figure 3)。In method 620, the WPA 20 operates according to program 610. During the operation of the WPA 20, steps 621 - 622 are performed, for example, at regular time intervals, to monitor the performance of the irradiation device 22. In step 621, an eigenvalue is derived from one or more measured values in the measurement signal S2. The corresponding eigenvalue represents the UV radiation intensity on the UV sensor 225. For example, the eigenvalue can be given by a single measured value, the time average of multiple measured values, a low-pass filtered value, etc. The eigenvalue can be converted to the unit of UV radiation intensity. Alternatively, the eigenvalue can be given in the unit provided by the UV sensor 225, such as voltage. The eigenvalues from step 621 form a time series of values. In step 622, the time series of values is evaluated according to a detection criterion for detecting a fault in the irradiation device 22. If the detection criterion is not met, the operation of the WPA 20 continues, and step 622 causes step 621 to be performed at a future time point. If the detection criterion is met, step 622 causes the operation of the WPA 20 to stop (by step 623) and an alarm to be generated (by step 624). This alarm indicates a fault in the irradiation device 22. For example, the fault may be that the radiation power of the UV source 224 is too low, or there is too much sediment or other fouling in the chamber 221. In step 624, the feedback device 54 ( Figure 3 ) can be operated to provide the operator with an alarm signal, information about the reason for the stopped operation, or an instruction. For example, the operator can be instructed to check or perform maintenance on the irradiation device 22.

[0098] During such maintenance, the irradiation module 22A can be replaced and / or repaired. In addition, during maintenance, the performance of the filtration device 21 can be evaluated by collecting a sample of W1” downstream of the filtration device 21 and analyzing the chlorine in the sample. If the total chlorine increases, the filtration module 21A of the filtration device 21 can be replaced. Alternatively, whenever the irradiation module 22A requires maintenance, the filter module 21A can be replaced by default. Compared with the reference example in Figure 2 , the number of samples that need to be collected and analyzed is significantly reduced.

[0099] It should be understood that method 620 is performed on the premise that the filtration device 21 is operating normally.

[0100] In some embodiments, step 622 includes comparing the respective eigenvalue with the strength limit. If a predefined number (N) of eigenvalues are below the strength limit and N≥1, the detection criterion can be met. The strength limit can be set to ensure that when the eigenvalue is above the strength limit, the irradiation device 22 is operable to eliminate the target amount (see step 602). The strength limit can be determined in a verification procedure, in which the irradiation module 22A is tested under well-controlled conditions. The verification procedure may involve measuring the eigenvalue and analyzing the chlorine content in the treated water, including the source water with a reference concentration of total chlorine and one or more radiation powers of the UV source.

[0101] Depending on the type of failure, the change in the eigenvalue may be slow or fast. Gradual fouling of chamber 221 or gradual deterioration of the UV source 224 may result in a slow change, while a complete loss of the radiation power of one or more radiation-emitting elements in the UV source may result in a rapid change. Therefore, the control device can be configured to output different information / instructions according to the characteristics of the detected change.

[0102] Through extensive experiments, the applicant has determined the timing for on-line monitoring of the performance of the filtration device 21, especially for detecting the occurrence of channeling. Figure 8A An example of experimental results obtained for an irradiation device configured to emit UV radiation at 280 nm is shown. Water containing 0 ppm, 2 ppm, 4 ppm, 6 ppm or 8 ppm free chlorine is supplied to the irradiation device, and the average signal level (here voltage) in the measurement signal S2 is measured. Figure 8A Therefore, the measured signal levels for different free chlorine contents in the influent water are shown. Figure 8A Includes a trend line (dashed line), which is a polynomial fit to the measurement data. As shown, the signal level of S2 decreases monotonically with the increase in the amount of free chlorine. This decrease is the result of the absorption of UV radiation by free chlorine. When the wavelength of the UV radiation is appropriately matched with the extinction coefficient of monochloramine, a similar result is expected for monochloramine ( Figure 5 ). Channeling in the filtration device 21 is expected to cause a rapid increase in the total chlorine concentration downstream of the filtration device 21, for example, from less than 0.1 ppm to 2 - 4 ppm depending on the concentration of total chlorine in the water supply W1. According to Figure 8A , this increase will result in a detectable step change in the measurement signal S2.

[0103] The ability of the above-mentioned irradiation device to remove free chlorine from the influent water was also tested. The concentrations of free chlorine were measured simultaneously in the influent and effluent waters during operation of the irradiation device. This experiment was carried out for different concentrations of free chlorine in the influent water. The results are as Figure 8BAs shown. As shown, through the operation of the irradiation device 22, the concentration of free chlorine decreases sharply. Similar results are expected for monochloramine and dichloramine. Considering the limitations of the experimental setup, it can be foreseen that by directly optimizing the radiation power of the UV source in the irradiation device 22 and / or the wavelength of the UV radiation, for example as referred to above Figure 5 described, the total chlorine concentration in the effluent can be reduced to 0.1 ppm or below 0.1 ppm. This experiment shows that, as expected, the irradiation device 22 is capable of effectively removing chlorine from the water supply W1.

[0104] Figure 6D is an example method 630 for monitoring the operating state of the filtration device 21 according to an embodiment. The method 630 can be executed by the control device 50 ( Figure 3 ). First, the method 630 will be described for the irradiation module 22A in Figure 9A , which is similar to the module 22A in Figure 4A . In the method 630, the WPA 20 operates according to the program 610. During the operation of the WPA 20, for example, step 631 is executed at regular time intervals to detect a step change reduction in the measurement signal S2. Figure 9B shows an example of such a step change. When a channel is formed in the filtration device 21 at time tb, a step change occurs, causing the device 21 to supply water with an increased chlorine concentration to the irradiation device 22. In step 631, the step change can be detected in any suitable manner, for example, by detecting that the measured intensity drops below the intensity threshold T1, as Figure 9B shown. The threshold T1 can be predefined or set relative to a dynamic reference level, which can be given by the most recently measured intensity value in S2, for example, the average value. Thus, in some embodiments of step 631, the reference level is determined based on the previous signal values in S2 at the current time point, the threshold T1 is set relative to the reference level, and the signal level in S2 at the current time point is compared with T1. Alternatively or additionally, a step change can be detected when the derivative of the measured intensity exceeds the derivative threshold. The derivative of the measured intensity can be determined by differentiating the signal S2. The measured intensity can be given by the above eigenvalue ( Figure 6C , step 621). Step 631 can also require that the measured intensity remains below T1 for a predefined period of time before a step change is considered to have been detected.

[0105] If no step change is detected in step 631, the operation of the WPA continues, and step 633 causes the method 630 to execute step 631 at a future time point. If a step change is detected, then step 633 causes the operation of the WPA 20 to stop (step 634) and an alarm to be generated (step 635). In step 635, the feedback device 54 can be operated ( Figure 3)to provide an alarm signal, information about the reason for stopping the operation, or an instruction to the operator. For example, the operator may be instructed to perform maintenance of the filtration device 21.

[0106] Method 630 provides a significant technological advancement as it allows for the online monitoring of the performance of the filtration device 21. This will effectively eliminate the need to collect and analyze water samples (see Figure 3 and Figure 4A for W1”).

[0107] It can also be noted that the intermittent spikes in the chlorine concentration in the above-mentioned water supply W1 are likely to be visible in the measurement signal S2. Method 630 can be designed or not designed to distinguish, for example, signal features originating from intermittent spikes in the water supply W1 and step changes caused by channeling based on differences in derivatives and / or amplitudes and / or durations.

[0108] As Figure 6D shown by the dashed box in Figure 8B , method 630 may include a step 632 of monitoring another measurement signal S2’ to detect step changes. Step 632 is based on insights derived from the experimental data in Figure 8B . The experimental data shows that the concentration of free chlorine in the effluent water ( Figure 8B squares) decreases monotonically as the concentration of free chlorine in the influent water decreases ( Figures 8A to 8B circles). By considering the data in

[0109] together, this means that a step increase in the chloride concentration of the influent water to the irradiation device 22 caused by channeling in the filtration device 21 will not only result in a step decrease in the signal level in S2 but also an increase in the chloride concentration in the effluent water. By detecting this concentration increase, the certainty of channeling detection can be improved.

[0109] As Figure 10A shown, the signal S2’ can be provided by the irradiation module 22A. Another UV sensor 225’ is arranged downstream of the chamber 221 to receive UV radiation generated by another UV source 224’. In the example shown, another UV source 224’ and another UV sensor 225’ are arranged in another chamber 221’ defined by another housing 220’ and are fluidly connected to the output port of the housing 220. The shown arrangement is given only as an example, and another UV sensor 225’ can be arranged at any position directly or indirectly irradiated by another UV source 224’. Another housing 220’ can be a separate measuring unit or an integral part of a pipe extending from the outlet. Another UV source 224’ may or may not be the same as the UV source 224. It is conceivable that the UV source 224’ emits UV radiation at a wavelength (partially) different from that of the UV source 224. The radiation power of another UV source 224’ may be lower compared to the UV source 224 as its purpose is not dechlorination but to measure the total chloride remaining in the water passing through the chamber 221.Figure 10B An example of a step change reduction in the measurement signal S2' due to channel formation in the filtering device 21 at time tb is shown. As shown, there may be a delay from time tb until the water with increased chloride concentration reaches chamber 221'. Depending on the degree of mixing in chamber 221, the step change in signal S2' may be slower than the step change in signal S2. After channel formation, chamber 221 most likely contains water from before and after channel formation. As the mixing in chamber 221 increases, when water flows from chamber 221 into chamber 221', the UV sensor 225' may detect a gradual decrease in the signal level (a slower step change).

[0110] Similar to step 631, a step change reduction can be detected in step 632. In some embodiments, the step change is detected when the measured intensity in signal S2' drops below an intensity threshold T2, as Figure 10B shown. Similar to threshold T1, threshold T2 can be predefined or set relative to a dynamic reference level. Step 633 can also require that the measured intensity remain below T2 for a predefined period of time before a step change is considered to have been detected.

[0111] Step 633 can be configured to logically combine the results of steps 631 and 632 to determine whether method 630 should proceed to step 634. Thus, the risk of false positives in the determination of step 633 can be reduced.

[0112] In some embodiments, step 633 applies a logical "AND" between the results of steps 631 and 632 such that step 633 proceeds to step 634 only when a time-synchronized step change is detected in both signals S2 and S2'. For example, step 633 may require that a step change occur in S2 and S2' within a predefined period of time. In other embodiments, step 633 applies a logical "OR" between the results of steps 631 and 632 such that step 633 proceeds to step 634 when a step change is detected in at least one of signal S2 and signal S2' within a predefined period of time. It is also conceivable that step 633 switches between applying a logical "AND" or a logical "OR". In one example, step 633 can default to using a logical "AND" and switch to a logical "OR" when the detection confidence in step 631 or step 632 is low. For example, step 631 and / or step 632 can provide a confidence value for each detected step change. The confidence value can be given by the magnitude of the signal decrease during the step change and / or the derivative of the step change.

[0113] Figure 7 is a schematic diagram of an exemplary main subsystem 20". Figure 7For providing further context only and not intended to limit the present disclosure in any way. The main subsystem 20” includes an inlet 120A for dechlorinated water W1’ and an outlet 120B for conditioned water W2. The inlet pipeline 121 extends from the inlet 120A to a tank 122 for intermediate storage of dechlorinated water. The connecting pipeline 123 extends from the tank 122 to the feed side 125A of the RO module 125. The RO module 125 is of a conventional structure and includes an RO membrane 125’ that divides the RO module 125 into a feed side 125A and a permeate side 125B. The RO membrane 125’ can be a semi-permeable membrane. The RO module 125 is configured to remove impurities such as microorganisms, pyrogens, and ionic substances from the dechlorinated water by the action of reverse osmosis. A fluid pump 124 is arranged in the connecting pipeline 123. A drain pipeline 126 extends from the feed side 125A to a drain pipe 127. In the illustrated example, an on / off valve 128 is arranged in the drain pipeline 126, and a reflux pipeline 129 extends from the drain pipeline 126 upstream of the valve 128 to the connecting pipeline 123 downstream of the fluid pump 124. Another fluid pump 130 is arranged in the reflux pipeline 129. A connecting pipeline 131 extends from the permeate side 125B to a post-treatment module 132.

[0114] In operation, the pump 124 is started to drive the dechlorinated water from the tank 122 into the feed side 125A of the RO module 125, thereby applying sufficient pressure to overcome the osmotic pressure. Thus, the incoming flow of dechlorinated water, known as the feed water, is divided into wastewater on the feed side 125A and purified water (permeate water) on the permeate side 125B. In the first operating mode, the valve 128 is opened, and the wastewater is conveyed along the drain pipeline 126 to the drain pipe 127. In the second operating mode, the valve 128 is closed, and the pump 130 is started so that the wastewater is recycled back to the connecting pipeline 123 and pumped back into the RO module 125. The recycling increases the feed flow rate of the RO module 125 to reduce fouling and scaling of the RO membrane 125’. The RO module 125 can be appropriately switched between the first and second operating modes. In the third operating mode, the valve 128 is opened to an appropriate degree or at appropriate intervals, dividing the wastewater into a wastewater stream recycled by the pump 130 and a drain stream that is simultaneously passed into the drain pipe 127. The resulting permeate water is conveyed in the connecting pipeline 131 to the post-treatment module 132.

[0115] The post-treatment module 132 is configured to refine the permeate water to further remove ions from the permeate water, thereby producing conditioned water W2, which is provided to the outlet 120B on the outlet pipeline 133. The permeate water is refined using a refining device such as an electro-deionization (EDI) device, an ion exchange device such as a mixed bed filtration device, or an RO module. The mixed bed filtration device includes a column or container having a mixed bed ion exchange material.

[0116] The post - processing module 132 or another module downstream of the post - processing module 132 may also include ultrafiltration to remove bacteria and endotoxins. Then, one or more ultrafilters may be used.

[0117] Although the subject matter of the present disclosure has been described in connection with the presently considered most practical embodiments, it should be understood that the subject matter of the present disclosure is not limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

[0118] Moreover, although the operations are depicted in the drawings in a particular order, this should not be understood as requiring that the operations be performed in the particular order shown or in sequential order, or that all of the illustrated operations be performed to achieve the desired result.

Claims

1. A water treatment device, the water being for medical use on a human body or an animal body (P), the device being configured to receive a water supply (W1) from a water source (10), and the device comprising: A filtration device (21) configured to effectively remove chlorine from the water supply by using one or more activated carbon filters (100), and An irradiation device (22) configured to effectively remove chlorine from the water supply (W1) by ultraviolet (UV) irradiation, wherein the filtration device (21) and the irradiation device (22) are connected in series to successively process the water supply (W1) into dechlorinated water (W1'), and wherein the device is configured to provide conditioned water (W2) for the medical use based on the dechlorinated water (W1').

2. The device according to claim 1, wherein the irradiation device (22) comprises a housing (220) defining a treatment chamber (221), an inlet (222) for introducing water into the treatment chamber (221), and an outlet (223) for discharging water from the treatment chamber (221), wherein the irradiation device (22) further comprises at least one UV radiation source (224) arranged to irradiate at least a part of the treatment chamber (221).

3. The device according to claim 2, wherein the irradiation device (22) further comprises at least one sensor (225) arranged to generate a measurement signal (S2) indicative of the UV radiation intensity in the treatment chamber (221), and wherein the device further comprises a control device (50) configured to receive the measurement signal (S2) and monitor the operation of at least one of the irradiation device (22) or the filtration device (21) based on the measurement signal (S2).

4. The device according to claim 3, wherein the control device (50) is configured to evaluate the relationship between the UV radiation intensity in the treatment chamber (221) and an intensity limit based on the measurement signal (S2), and generate an alarm when the UV radiation intensity drops below the intensity limit to indicate a failure of the irradiation device (22).

5. The device according to claim 4, wherein the failure includes at least one of a reduction in the radiation power of at least one UV radiation source (224) or fouling in the treatment chamber (221).

6. The device according to any one of claims 4 or 5, wherein the intensity limit corresponds to the irradiation device (22) being operable to effectively remove chlorine from the water supply (W1).

7. The device according to any one of claims 2-6, wherein the at least one UV radiation source (224) comprises a light-emitting diode or a laser diode.

8. The device according to any one of claims 2-7, wherein the at least one UV radiation source (224) comprises a first radiation-emitting element (L1) and a second radiation-emitting element (L2), wherein the first and second radiation-emitting elements (L1, L2) are configured to emit UV radiation in different wavelength ranges.

9. The device according to claim 8, wherein the control device (50) is configured to activate the first radiation emitting element (L1), the second radiation emitting element (L2), or both the first and second radiation emitting elements (L1, L2) to remove chlorine from the water supply (W1).

10. The device according to claim 8 or 9, wherein the control device (50) is configured to selectively activate at least one of the first or second radiation emitting elements (L1, L2) based on input data representing the chlorine composition in the water supply (W1).

11. The device according to any one of claims 8 - 10, wherein the first radiation emitting element (L2) is configured to preferentially remove monochloramine rather than free chlorine and dichloramine, and the second emitting element (L1) is configured to preferentially remove free chlorine and dichloramine rather than monochloramine.

12. The device according to any one of claims 8 - 11, wherein the first radiation emitting element (L1) is configured to generate UV radiation having a peak in a first wavelength range of 240 - 265 nm, and the second emitting element (L2) is configured to generate UV radiation having a peak in a second wavelength range of 265 - 290 nm.

13. The device according to any one of claims 2 - 12, wherein the at least one UV radiation source (224) is configured to generate UV radiation in a wavelength range of 100 - 400 nm and preferably in a wavelength range of 200 - 325 nm.

14. The device according to any one of claims 2 - 13, wherein the irradiation device (22) is configured to operate in a case where water flows continuously from an inlet (222) of the treatment chamber (221) to an outlet (223).

15. The device according to any one of the preceding claims, wherein the control device (50) is configured to detect channel formation in one or more activated carbon filters (100) of the filtration device (21) based on the measurement signal (S2), and generate an alarm signal when the channel formation is detected.

16. The device according to claim 15, wherein the control device (50) for the channel formation detection is configured to evaluate the measurement signal (S2) to detect a step change decrease in the measurement signal (S2).

17. The device according to claim 16, wherein the control device (50) is configured to detect the step change decrease by comparing the signal level in the measurement signal (S2) with a threshold (T1).

18. The device according to claim 17, wherein the control device (50) is configured to determine a reference level based on a previous signal value in the measurement signal (S2) at a current time point, set a threshold related to the reference level, and compare the signal level in the measurement signal at the current time point with the threshold (T1).

19. The device according to any one of claims 15 - 18, wherein the irradiation device (22) comprises another UV radiation source (224') and another sensor (225'), which are arranged downstream of the at least one source (224) and the sensor (225), wherein the another sensor (225') is arranged to generate another measurement signal (S2') to indicate the intensity of the UV radiation received from the another source (224'), and wherein the control device (50) is configured to detect the channel formation based on the measurement signal (S2) and the another measurement signal (S2').

20. The device according to claim 19, wherein the control device (50) for the channel formation detection is configured to evaluate the another measurement signal (S2') to detect a decrease in another step change in the another measurement signal (S2').

21. The device according to claim 20, wherein the control device (50) is configured to generate the alarm signal when it is detected that a decrease in another step change in the another measurement signal (S2') is temporally synchronized with a corresponding decrease in the step change in the measurement signal (S2).

22. The device according to any one of the preceding claims, wherein the filtration device (21) is arranged upstream of the irradiation device (22).

23. The device according to any one of the preceding claims, wherein the filtration device (21) and the irradiation device (22) are included in a pretreatment subsystem (20'), and wherein the device further comprises a main subsystem (20"), which is arranged to receive the dechlorinated water (W1') from the pretreatment subsystem (20') and is configured to process the dechlorinated water (W1') to produce conditioned water (W2).

24. The device according to claim 23, wherein the main subsystem (20") comprises at least one of a reverse osmosis device or an ion exchange device.

25. The device according to any one of the preceding claims, wherein the filtration device (21) and the irradiation device (22) are connected in series without an intermediate treatment device for removing chlorine.

26. The device according to any one of the preceding claims, which is configured to supply the conditioned water (W2) to a dialysis machine (30).

27. The device according to any one of the preceding claims, wherein the filtration device (21) comprises a single activated carbon filter (100), which is configured to effectively remove chlorine from the supply water (W1).

28. The device according to any one of the preceding claims, wherein the irradiation device (22) is configured to remove a first target amount of chlorine from the supply water (W1), and wherein the filtration device (21) is configured to remove a second target amount of chlorine from the supply water (W1), wherein the second target amount is at least equal to the first target amount and less than twice the first target amount.

29. A system, comprising a water production device (20) according to any one of the preceding claims, and a dialysis machine (30), the dialysis machine being fluidly connected to receive conditioned water (W2) from the water production device (20).

30. A water production method, the water being for medical use in a human or animal body, the method comprising: receiving (611) a water supply from a water source; operating (612, 613) a filtration device and an irradiation device connected in series to sequentially process the water supply into dechlorinated water, wherein the filtration device is configured to effectively remove chlorine in the water supply by activated carbon filtration, and wherein the irradiation device is configured to effectively remove chlorine in the water supply by ultraviolet UV irradiation; and providing (615) conditioned water for the medical use based on the dechlorinated water.

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