Sanitising system for drinking water systems

Abstract

Abstract A system for sanitising water and cleansing a fluid pathway in a drinking water dispensing assembly is disclosed. The system comprises an inlet for receiving pressurised water, a sanitising device arranged downstream of the inlet, a pressure- compensating flow restrictor for regulating fluid flow through the system, a sensing 5 device positioned downstream of the sanitising device, and an outlet for delivering treated water. The sanitising device includes a housing containing two or more spaced electrode plates configured to subject the water to in-line electrochemical treatment as it flows between the electrodes. Electrochemical reactions at the electrodes generate oxidising and reducing species in the water, including reactive oxygen species, halogen-10 based species, hydrogen and hydrogen peroxide, for sanitisation of the water and cleansing of the fluid pathway. Abstract 10 20 25 28 36 02 19 D ec 2 02 5 2 0 2 5 2 8 3 6 0 2 1 9 D e c 2 0 2 5 2 / 4 Fi gu re 2 200 102 110 106 108 112 104 2 / 4 2 120 120 120 120 204 206 202 Figure 2 20 25 28 36 02 19 D ec 2 02 5 2 0 2 5 2 8 3 6 0 2 1 9 D e c 2 0 2 5

Description

2025283602   19 Dec 2025 TECHNICAL FIELD The present invention relates to a system for sanitising a fluid and a fluid pathway in a drinking water dispensing assembly. The invention has primarily been developed for use with drinking 5 water dispensers and will be described hereinafter with reference to this non-limiting application. BACKGROUND A known water dispenser typically comprises a fluid pathway that conveys filtered tap water to a reservoir, from which it is then dispensed to an outlet for use by a consumer. Modern dispensers 10 may include an outlet that dispenses filtered water, chilled still water, sparkling / carbonated chilled water, remineralised water, and / or boiling water. A disadvantage of known water dispensers is that the water contained within the fluid pathway is susceptible to infiltration and contamination by common waterborne bacteria and opportunistic pathogens (e.g. Legionella spp. and Pseudomonas aeruginosa). Water contaminated by 15 waterborne bacteria or opportunistic pathogens can spread throughout municipal water systems, such as residential or commercial plumbing systems and water tanks, and subsequently enter the fluid pathway of water dispensers. Water can alternatively be contaminated through back-contamination at the water outlet spouts. Filtration systems within conventional water dispensers may not adequately filter out all bacteria or pathogens. Such known systems do not perform full 20 system cleansing and / or sanitisation steps during installation of the filter cartridge into the dispenser assembly. Water contaminated with bacteria or pathogens is particularly harmful to persons with weakened immune systems or patients with respiratory diseases, potentially causing death. For example, exposure to Legionella can occur when a person inhales small water droplets (such as from a 25 showerhead or while drinking water dispensed from a water dispenser) containing Legionella bacteria. Thermal treatment, chlorination, chloride dioxide, copper and silver ions, ozone, ultraviolet light, hypochlorous acid have all been used to treat water. Although most mains water supplies have residual levels of active chlorine or chloramine, filtration systems with activated carbon remove 30 the chlorine / chloramine, leaving the post-filtration reticulation unprotected and open to bacteria proliferation. 2025283602   19 Dec 2025 Known sanitising systems for water dispensers are complex, not user-friendly and do not adequately reduce or eliminate bacteria or opportunistic pathogen proliferation within the fluid pathway. Accordingly, there is a need for an improved sanitising system. 5 SUMMARY OF THE INVENTION It is an object of the present invention to substantially overcome, or at least ameliorate, one or more of the disadvantages of existing arrangements, or at least provide a useful alternative to existing arrangements. A sanitising system for sanitising water and cleansing a fluid path in a drinking water dispensing 10 assembly is described herein, the system comprising: • an inlet to receive a supply of water to be delivered under pressure along the fluid pathway; and • a sanitising device positioned in fluid communication downstream of said inlet; and • a pressure compensating flow restrictor configured to regulate the flow rate of the fluid 15           delivered to the fluid pathway and allow the fluid to be delivered to the sanitising device at a flow rate appropriate to ensure an effective disinfection treatment; and • a sensing device positioned in fluid communication downstream of said sanitising device; and • an outlet in fluid communication downstream of said inlet to deliver the sanitised and 20           cleansing fluid to a user. The sanitising device comprises a housing for two or more electrode plates (sanitising device electrodes) spaced apart, so as to allow in-line electrochemical treatment of the fluid; the housing surrounding the electrodes is preferably designed so as to force all fluid to pass through the space(s) between the electrodes. 25   The in-line electrochemical treatment of the fluid is carried out using electrode plates suitable for contact with drinking water; the anodic oxidation of the fluid produces oxidising species such as hydroxyl radicals and nascent oxygen, generally referred to as reactive oxygen species (ROS), in addition to halogen radicals, hypohalogenous acid and hypohalogenite anions. The latter species are generally chlorinated species (chlorine radicals, hypochlorous acid and hypochlorite 30 anions) but traces of brominated and / or iodinated species may also be formed. The cathodic reduction of the fluid produces reducing species such as hydrogen, but also further oxidising species such as hydrogen peroxide, through the reduction of oxygen molecules formed at the anode(s). 2025283602   19 Dec 2025 WO 2022 / 261696 A1 describes an electrochemical reactor suitable for treating water flow rates higher than those required by the present application; however, the characteristics of the reactor are ideally maintained and replicated in the present case. The sensing device comprises an all-solid-state potentiometric sensor, based on the open circuit 5 potential difference between two dissimilar electrodes or probes (sensing device electrodes). JP 6518937 B2 describes a method for detecting residual chlorine in tap water, in which a pair of electrodes are immersed in the water and free residual chlorine is detected based on the voltage generated between the electrodes. The metal constituting the first electrode (Platinum) is more responsive to free residual chlorine in tap water than the metal constituting the second electrode 10   (316 or 316L stainless steel); according to the inventors, the electrode potential of both electrodes must vary similarly with changes in tap water quality and environmental factors. In JP 7089434 B2, the above method is improved by considering two pairs of electrodes: a first voltage is detected by immersing a first pair of electrodes in tap water after removing any free residual chlorine; a second voltage is detected by immersing a second pair of electrodes in tap 15 water containing free residual chlorine, and the free residual chlorine is detected based on the difference between the two voltages. Again, each electrode pair consists of one Platinum electrode and a 316 or 316L stainless steel electrode. As discussed in Sensors and Actuators B, 248, 1037 (2017), and later confirmed in Journal of The Electrochemical Society, 168, 117516 (2021), various pure metals (platinum, iron, aluminium) 20 and alloys (commercially available stainless steel: SS 304, 316, and 430) were evaluated as sensor material candidates. Both platinum and stainless-steel electrodes were found to be sensitive to residual chlorine, and their sensitivities were different enough to extract a differential signal. Additionally, they exhibited similar sensitivity to potential environmental factors. A sensing device consisting of platinum and SS 316 responded selectively to residual chlorine, almost 25 independently of pH. Although the potentiometric sensor described above may seem suitable for measuring free residual chlorine in tap water resulting from the in-line electrochemical treatment performed inside the sanitisation device of the present invention, laboratory tests have confirmed that this is not the case: the in-line electrochemical treatment, in addition to producing free residual chlorine, also 30 produces hydrogen, which is in turn detected by the sensor. On one or both of the suggested metals, the kinetics of the hydrogen oxidation reaction (to produce protons) is faster than that of the chlorine reduction reaction (to form chloride), and the result is that the potential difference between the two metals decreases as the free residual chlorine increases, as a consequence of the increase in hydrogen concentration. In other words, although the potential measured by the 2025283602   19 Dec 2025 sensor is the difference between the open circuit potentials (also referred to as the equilibrium potentials, the rest potentials, or the corrosion potentials) of the two metals immersed in solution (each of which is a mixed potential), the sensor is more sensitive to hydrogen than to chlorine. In a first aspect, the present invention provides a sanitising system for sanitising water and 5 cleansing a fluid path in a drinking water dispensing assembly. In a second aspect, the present invention provides a sanitising system that is suitable for producing water with a desired level of free residual chlorine. In another aspect, the present invention provides a system capable of self-regulating its operating parameters to produce the desired level of free residual chlorine. 10 Also disclosed herein is a method for sanitising a fluid and a fluid pathway in a drinking water dispensing assembly, using the free residual chlorine produced by a sanitising device. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic diagram of a water dispensing unit. 15 Figure 2 is a schematic diagram of the water dispensing unit of Figure 1, with the sanitising system of the present invention installed in the fluid pathway. Figure 3 is a graph showing the linear relationship between the response of the sensing device (open-circuit potential difference between the two sensing probes) and the current supplied to the sanitising device of the present invention. 20 Figure 4 is a graph showing the linear relationship between the active chlorine produced and the current supplied to the sanitising device of the present invention (the incoming tap water contained approximately 75 mg / L of chloride and was filtered with activated carbon to remove any traces of active chlorine). 25 DETAILED DESCRIPTION Figure 1 schematically depicts an exemplary water dispensing system 100 for dispensing water through a fluid pathway 120 to a water dispensing outlet 104. By way of example, the dispensing outlet 104 may represent a multifunctional water dispensing assembly capable of dispensing 2025283602   19 Dec 2025 filtered water, chilled still water, sparkling / carbonated chilled water, remineralised water, and / or boiling water. The system 100 includes an inlet assembly 102, a pressure-limiting valve (PLV) 106, a filter assembly 108, a water storage tank 110, and a pressure-compensated flow regulator or restrictor 112. Since modern dispensers may include an outlet that delivers filtered water, 5 chilled still water, sparkling / carbonated chilled water, remineralised water, and / or boiling water, the system 100 may also include other elements (additional storage tanks, cooling and / or heating elements, carbon dioxide injection, automatic valves and the like) which are however not essential to illustrate the present invention. The inlet assembly 102 is designed for receiving a supply of water under pressure, typically from 10 a mains water supply. At the inlet assembly 102 the water pressure is regulated by the PLV 106 to ensure that water pressure within the fluid pathway 120 remains below a pre-set value (e.g., 500 kPa). Water from the inlet assembly 102 is conveyed to the filter assembly 108, which can comprise a filter head manifold and a detachably removable filter unit; the latter may further comprise a pleated membrane, a particle removal medium, and / or a carbon filter material, for 15 purifying the water supplied from the inlet assembly 102. Attached to (or included in) the filter unit is a filter key that allows the filter unit to be connected to the filter head manifold. Purified water leaving the filter unit is conveyed downstream to a pressure-compensated flow regulator (FR) or restrictor 112, which is configured to maintain a constant flow rate of purified water through the fluid pathway 120 at varying static pressures (e.g., between 100 and 500 kPa). 20 The flow of water through the inlet assembly 102 to the water storage tank 110 may be further controlled or regulated by one or more valves. Preferably, the constant flow rate of purified water is between 1.0 litres / min and 3.0 litres / min. In many domestic or commercial purified drinking water dispensing systems, the flow rate is maintained at approximately 2.5 litres / min. Note that a single water storage tank 110 is shown in Figure 1, but modern dispensing units may include an 25 outlet that dispenses filtered water, chilled still water, sparkling / carbonated chilled water, remineralised water, and boiling water, and thus require multiple storage tanks. Downstream of the flow restrictor 112 is the water storage tank 110 for receiving the purified water through a tank inlet (not shown). A tank outlet (not shown) conveys the water from the water storage tank 110 to the outlet 104. 30 The system 100 may also include a smart firmware protocol (not shown) to allow the user to set various process parameters (e.g., maximum and minimum temperatures for the dispensed chilled and / or boiling water, etc.) or to guide the user through several processes. The firmware may be available during the product commissioning phase or made available in a later phase of the maintenance service. 2025283602   19 Dec 2025 A system 200 according to a first embodiment of the present invention is represented in Figure 2. The system 200 has an identical configuration to the system 100 of Figure 1, apart from the presence of the sanitising system 202, which is installed between the pressure-compensated flow regulator or restrictor 112 and the inlet of the water storage tank 110. 5 The sanitising system 202 comprises a sanitising device 204, a sensing device 206, and a high-input impedance electrometer (not shown) for measuring the voltage generated between electrodes (sensing device electrodes) in the sensing device 206. The system 200 also include a smart firmware protocol (not shown) to allow the conversion of said measured voltage into a free residual chlorine value. The sanitising device 204 is also connected to a direct current power 10 supply (not shown) capable of periodically reversing the polarity of electrodes (anode(s) and cathode(s)) in the sanitising device 204, to clean the cathode(s) of any limescale deposits. In a preferred embodiment of the present invention, periodic polarity inversion may be performed at regular intervals of operating time, such as every hour, or every 10 minutes; more generally, polarity may be reversed at operating time intervals ranging from about 1 to 1440 minutes, said 15 time interval being chosen based on the characteristics of the fluid to be treated, and the current supplied to the sanitising device 204. According to the present invention, when water from the inlet assembly 102 is conveyed into the sanitising system 202, the in-line electrochemical treatment performed within the sanitising device 204 enables the production of oxidants such as: ozone, hydrogen peroxide and other peroxide 20 species, hydroxyl radicals, as well as chlorine-based oxidants, the quantities and concentrations of which are determined by the quantity and type of compounds precursors that are fed into the sanitising device 204, the water flow rate, the intensity of the current fed to the sanitising device 204, and related electrode material. As a result, the water inside the sanitising device 204 is sanitised and enriched with free residual 25   chlorine, which can then exert its sanitising power downstream, also against any contamination coming from the water outlet spout. Since the end user of the system may not appreciate the presence of chlorine in the water, it is desirable that the system maintains a level of chlorine just high enough to ensure that the water is free of contamination and that the fluid path is also kept clean. This is the role of the sensing 30 device 206, which provides information to the smart firmware protocol so that it can adjust / manage the intensity of the current sent to the sanitising device 204. Although the sanitising system 202 includes both the sanitising device 204 and the sensing device 206, the two devices can be installed at a certain distance from each other; for example, the sensing device 206 may be installed in proximity to the inlet of the water storage tank 110. 2025283602   19 Dec 2025 The sensing device 206 comprises a potentiometric sensor made of a pair of electrodes in contact with the water flowing inside the liquid pathway 120; the voltage generated between the electrodes is measured using a high-input impedance voltmeter (not shown in Figure 2) and correlated to the free residual chlorine in the water. In contrast to what is described in the prior 5 art, at least one of the electrodes is made of a non-metallic conductive material or a (semi)conductive oxide deposited on a conductive support. The choice of materials is essential for the sensor to be able to respond to the free residual chlorine content, while remaining substantially insensitive to the presence of hydrogen. Although the concentration of the latter increases with the current supplied to the sanitising device, similarly to what happens for the 10 concentration of free residual chlorine in a treated water containing chlorides, it is not possible to measure the concentration of free residual chlorine based on the concentration of hydrogen, for the simple fact that the electrolysis of chloride-free water is still capable of producing hydrogen but is clearly not capable of producing any active chlorine. The author of the present invention has discovered that electrode materials suitable for the application in question are one or more 15 of the following electrode materials: carbon (graphite, amorphous carbon, glass-like carbon, or conductive diamond), doped tin oxide (a thin film on a suitable conductive support), platinumtantalum oxide mixtures (a thin film on a suitable conductive support), and gold (also in alloys containing other metals or as metal dispersed in a thin-film oxide mixture on a suitable conductive support). 20 Looking at the scientific papers cited previously, the typical response of the sensor based on the platinum - SS 316 electrode pair (which apparently provided the best results) takes several minutes to reach a relatively stable response: up to 10 minutes according to Figure 9 in Journal of The Electrochemical Society, 168, 117516 (2021), and at least 4 minutes according to Figure 5 in Sensors and Actuators B, 248, 1037 (2017). Those skilled in the art will recognise that this 25 timeframe is of no value for the present application, since the water tank in the drinking water dispensing unit is filled to capacity in a couple of minutes at most. However, the author of the present invention has found that by using the above-mentioned suitable electrode materials, the time required for the potentiometric sensor to produce a stable response can be reduced to less than 30 seconds. 30 Since several environmental factors have the potential to change the free residual chlorine yield produced by the sanitising device 204, the smart firmware protocol includes a calibration function that allows the system to be informed of the chlorine produced by the sanitising device 204 under at least two different current intensity conditions. The calibration procedure can be conveniently performed during the commissioning phase of the system but should be repeated whenever 35 significant changes in environmental factors occur (for example, variations in inlet water temperature, resulting from seasonal changes). 2025283602   19 Dec 2025 In a preferred embodiment of the present invention, the smart firmware protocol also contains instructions to limit the intensity of the current supplied to the sanitising device 204, so as to avoid any excessive production of free residual chlorine, or to monitor both the current supplied to the sanitising device 204 and its operating time, so as to allow an estimate of the remaining useful service life of the electrodes in the sanitising device 204. According to a preferred embodiment, the potentiometric sensor of the sensing device 206 is inserted into a self-cleaning flow cell containing beads capable of being displaced by the incoming flow; the continuous movement of the beads and their contact with the sensing parts of the sensor allows the self-cleaning action. Electrodes (sensing device electrodes) described herein may be formed from at least one electrically conductive material selected from carbon-based materials, doped tin oxide coatings, platinum-tantalum oxide mixtures, and gold-based materials. Any of these materials may be used individually or in combination, including mixtures, layered structures, composite coatings, graded compositions and multi-phase assemblies. In some embodiments, the electrode comprises a carbon material. Suitable carbon materials include graphite, amorphous carbon, glass-like carbon and conductive diamond. In further embodiments, the electrode comprises doped tin oxide, typically in the form of a thin conductive film deposited on a suitable conductive support. The doped tin oxide layer may be formed by spray pyrolysis, sol-gel coating, sputtering, chemical vapour deposition, or other known thin-film deposition methods. Suitable conductive supports include corrosion-resistant metals such as titanium, as well as other conductive substrates capable of withstanding electrochemical environments. In other embodiments, the electrode comprises a platinum-tantalum oxide mixture, generally provided as a catalytic or conductive thin film supported on a conductive substrate. The mixture may include platinum and tantalum oxide in any suitable ratio, depending on the required electrochemical performance. In yet further embodiments, the electrode comprises gold, a gold alloy, or gold dispersed within an oxide matrix or thin film. In some embodiments, gold may be provided as nanoparticles or other dispersed metallic species within a thin-film oxide mixture formed on a conductive support. Suitable supports include the same corrosion-resistant metals described above or any other compatible conductive substrate known to those of skill in the art. The electrode may comprise two or more of the above materials. For example, the electrode may include a carbon material in combination with gold; a doped tin oxide layer in combination with a 8 2025283602   19 Dec 2025 platinum-tantalum oxide layer; or conductive diamond used alongside gold dispersed in a thin-film oxide matrix. Combinations may be arranged as mixed coatings, sequential layers, interpenetrating structures, composite electrodes or any other configuration in which the materials collectively provide the desired electrochemical properties. Although specific embodiments of the invention are illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternative and / or equivalent implementations exist. It should be appreciated that the exemplary embodiment or exemplary embodiments are examples only and are not intended to limit the scope, applicability, or configuration in any way. Rather, the foregoing summary and detailed description will provide those skilled in the art with a convenient road map for implementing at least one exemplary embodiment, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope as set forth in the appended claims and their legal equivalents. Generally, this application is intended to cover any adaptations or variations of the specific embodiments discussed herein. It will also be appreciated that in this document the terms “comprise”, “comprising”, “include”, “including”, “contain”, “containing”, “have”, “having”, and any variations thereof, are intended to be understood in an inclusive (i.e. non-exclusive) sense, such that the process, method, device, apparatus or system described herein is not limited to those features or parts or elements or steps recited but may include other elements, features, parts or steps not expressly listed or inherent to such process, method, article, or apparatus. Furthermore, the terms “a” and “an” used herein are intended to be understood as meaning one or more unless explicitly stated otherwise. Moreover, the terms “first”, “second”, etc. are used merely as labels, and are not intended to impose numerical requirements on or to establish a certain ranking of importance of their objects. The following example, whose purpose is purely illustrative and not limiting the present invention, is provided to describe the use of the sanitising system and highlight some characteristics of its constituent elements. Example 1. As detailed in the summary of the invention, a sanitising system for sanitising water and cleansing a fluid path in a drinking water dispensing assembly comprise: • an inlet to receive a supply of water to be delivered under pressure along the fluid pathway; and • a sanitising device positioned in fluid communication downstream of said inlet; and 2025283602   19 Dec 2025 • a pressure compensating flow restrictor configured to regulate the flow rate of the fluid delivered to the fluid pathway and allow the fluid to be delivered to the sanitising device at a flow rate appropriate to ensure an effective disinfection treatment; and • a sensing device positioned in fluid communication downstream of said sanitising device; 5         and • an outlet in fluid communication downstream of said inlet to deliver the sanitised and cleansing fluid to a user. To perform tests, a sanitising system was assembled by considering the following elements: • a connection to a tap water supply with a manual valve; 10       • an activated carbon filter, to remove any residual free chlorine from the water; • an in-line digital flow meter, to monitor the water flow rate through the system; • a sanitising device containing three plate electrodes with an active (anodic) surface area of approx. 95 cm2 and an internal (void) volume of 10.6 mL; • a variable DC benchtop power supply with a 0-120V output range and a maximum current 15           of 3A; • a sensing device consisting of two ring-shaped sensing probes (one made of graphite and the other of 9-carat gold; each with a surface area of approx. 37.7 mm2) positioned 5 mm apart in a self-cleaning flow cell; the cell, suitable for flows up to 1 L / min, also contained a dozen glass beads with a diameter of approx. 2.4 mm; 20       • a digital multimeter, to measure the open-circuit potential difference between the two probes of the sensing device • a benchtop photometer (Hanna Instruments, model HI96771), to check the chlorine content of the treated water. Due to the suboptimal design of the flow cell, which could not handle flow rates greater than 1 25 L / min, tests were conducted at a constant flow rate of 1 L / min. During these tests, the sanitising device was powered with currents ranging from 0.1 to 0.5A, producing active chlorine concentrations between 0.02 and 0.85 mg / L. While Australia and the United States allow higher chlorine concentrations (up to 5 mg / L and 4 mg / L, respectively) for disinfection, Europe prioritises lower aesthetic levels (around 0.3 mg / L) at the tap, suggesting that this concentration of active 30 chlorine produced in a drinking water dispensing unit would typically be sufficient for disinfection while maintaining acceptable taste and odour. Figure 3 shows the linear relationship between the response of the sensing device (open-circuit potential difference between the two sensing probes) and the current supplied to the sanitising device (which in turn determines the concentration of active chlorine produced as a result of the 35 electrochemical conversion of chlorides present in tap water). 2025283602   19 Dec 2025 Figure 4 shows the linear relationship between the concentration of active chlorine produced by the sanitising device and the current delivered. Tests were performed using tap water filtered with an activated carbon filter to remove any traces of active chlorine that may have been present due to the municipality’s water treatment system. 5 Figure 3 contains data recorded over several days (the test was performed daily, spanning nearly a month). Those familiar with the subject will notice the small variability in the sensor’s response to the active chlorine produced by a specific current value (this variability can be as high as about 30 mV when comparing measurements obtained on different days). Since there is a linear relationship between the active chlorine produced and the current supplied to the sanitising device 10 (see Figure 4), a 30mV difference in the measured voltage between the two probes translates into a variation in the active chlorine content of approximately 0.15 ppm. It is important to note that the sensing device is essential to optimise the operation of the sanitising device. The amount of chloride in water can vary geographically and seasonally, so powering the sanitising device with a constant current requires additional monitoring, which the sensing device 15 is capable of performing. REFERENCE NUMERAL LIST 2025283602   19 Dec 2025 100 Exemplary water dispensing unit 102 Inlet assembly 104 Water dispensing outlet 5   106 Pressure limiting valve (PLV) 108 Filter assembly 110 Water storage tank 112 Pressure-compensated flow restrictor 120 Fluid pathway 10   200 Exemplary water dispensing unit incorporating a sanitising system according to a first embodiment 202 Sanitising system 204 Sanitising device 206 Sensing device 15

Claims

2025283602   19 Dec 20251. A sanitising system for sanitising water and cleansing a fluid path in a drinking water dispensing assembly, the system comprising:5          • an inlet assembly (102) for receiving a supply of water to be delivered under pressurealong a fluid pathway; and• a sanitising device (204) positioned in fluid communication downstream of said inlet; and• a pressure-compensating flow restrictor (112) configured to regulate the flow rate of 10               the fluid delivered to the fluid pathway and allow the fluid to be delivered to saidsanitising device (204) at a flow rate appropriate to ensure an effective disinfection treatment; and• a sensing device (206) positioned in fluid communication downstream of said sanitising device (204); and15           • an outlet (104) in fluid communication downstream of said inlet to deliver the sanitisedand cleansing fluid to a user,wherein said sensing device (206) is used to manage the operation of said sanitising device (204).

2. A system according to claim 1, wherein said sanitising device (204) comprises a housing for 20 two or more electrode plates spaced apart, and the housing surrounding the electrodes is designed so as to force all fluid to pass through the space(s) between the electrodes.

3. A system according to any of the previous claims, wherein said sensing device (206) comprises a potentiometric sensor made of a pair of electrodes and at least one of the electrodes is made of a non-metallic conductive material or a (semi)conductive oxide 25 deposited on a conductive support.

4. A system according to claim 3, wherein one of the electrodes is made of carbon (graphite, amorphous carbon, glass-like carbon, or conductive diamond), doped tin oxide (a thin film on a suitable conductive support), or platinum-tantalum oxide mixtures (a thin film on a suitable conductive support).30   5. A system according to claim 3, wherein one of the electrodes is made of gold (also in alloyscontaining other metals or as metal dispersed in a thin-film oxide mixture on a suitable conductive support).2025283602   19 Dec 20256. A system according to any of the previous claims, wherein said sensing device (206) comprises a potentiometric sensor that works by measuring the open circuit potential difference between said pair of electrodes.

7. A system according to any of the previous claims, wherein the potentiometric sensor of the 5        sensing device (206) is inserted into an auto-cleaning flow cell.

8. A system according to any of the previous claims, wherein the self-cleaning flow cell contains beads capable of being displaced by the incoming flow, and the continuous movement of the beads and their contact with the sensing parts of the sensor enabling a self-cleaning action.

9. A system according to any of the previous claims, wherein said open circuit potential 10 difference is converted to a free residual chlorine value by using a smart firmware protocol.

10. A system according to claim 7, wherein said smart firmware protocol includes a calibration function that allows the system to be informed of the chlorine produced by the sanitising device (204) under at least two different current intensity conditions.

11. A system according to any of the previous claims, wherein water supplied from the inlet 15 assembly (102) is initially passed through a filter assembly (108) comprising a carbon filter material.

12. A method for sanitising a fluid and a fluid pathway in a drinking water dispensing assembly, the method including the steps of:• producing free residual chlorine by using a sanitising device (204);20          • measuring the amount of free residual chlorine produced by using a sensing device(206);• regulating the amount of free residual chlorine produced by said sanitising device (204) using the information provided by said sensing device (206) to adjust the intensity of the current sent to said sanitising device (204).25

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