System and method for purifying water

Abstract

In one aspect, the present disclosure provides a water purification system that includes a water inlet, a bacterial filter downstream of the water inlet, a fluid outlet downstream of the bacterial filter, and a source of a cleaning fluid in fluid communication with an inlet of the bacterial filter to provide the cleaning fluid upstream of the bacterial filter.

Description

SYSTEM AND METHOD FOR PURIFYING WATERFIELD

[0001] This disclosure relates to water purification systems for beverage dispensers.CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 694,552, filed September 13, 2024; and of U.S. Provisional Patent Application No. 63 / 706,201 , filed October 11 , 2024, the entire contents of which are incorporated herein by reference in their entirety.BACKGROUND

[0003] The following paragraphs are not an admission that anything discussed in them is prior art or part of the knowledge of persons skilled in the art.

[0004] There are numerous commercial, industrial, and medical devices used for purifying water to ensure it meets microbiological purity standards. These standards are typically measured by counting biological cells or their by-products in a given volume of water, with limits specified as CFU / ml and EU / ml. Conventional devices for water purification may include the application of chlorination / dechlorination, mechanical filtration, UV radiation, ozonation, deionisation, reverse osmosis, or a combination thereof.

[0005] However, achieving initial purity is not enough to ensure continued cleanliness at the point of use. Biological contaminants can still proliferate over time within the system, or contamination events may occur.INTRODUCTION

[0006] The following introduction is intended to introduce the reader to this specification but not to define any invention. One or more inventions may reside in a combination or sub-combination of the apparatus elements or method steps described below or in other parts of this document. The inventors do not waive or disclaim their rights to any invention or inventions disclosed in this specification merely by not describing such other invention or inventions in the claims.

[0007] Water purification systems that use mechanical filtration of bacteria to prevent contamination of the system downstream from the bacterial filter may still exhibit biological contamination over time, even if the bacterial filter is replaced on a regular basis. The authors of the present disclosure have determined that cleaning the upstream side of the bacterial filter using a cleaning fluid, for example on a daily basis, may help reduce or prevent the incidence of biological contamination of the system, such as over the lifetime of the bacterial filter; or may help extend the lifetime of the bacterial filter.

[0008] In one aspect, the present disclosure provides a water purification system that includes a water inlet, a bacterial filter downstream of the water inlet, a fluid outlet downstream of the bacterial filter, and a source of a cleaning fluid in fluid communication with an inlet of the bacterial filter to provide the cleaning fluid upstream of the bacterial filter.

[0009] In another aspect, the present disclosure provides a water purification system that includes one or more bacterial filters, and a source of a cleaning fluid upstream of at least one of the bacterial filters. The source of the cleaning fluid may be upstream of all of the bacterial filters in the system.

[0010] In yet another aspect, the present disclosure provides a source of cleaning fluid in fluid communication with a side of a bacterial filter in a water purification system, where the side of the bacterial filter faces unsterilized water. The bacterial filter may be the most upstream bacterial filter in the water purification system.

[0011] In still another aspect, the present disclosure provides a flow path in a water purification system. The flow path includes a water supply conduit fluidly connecting a source of cleaning fluid to a bacterial filter, where the water supply conduit supplies a cleaning fluid to a side of the bacterial filter that faces unsterilized water.

[0012] In water purification systems discussed herein, during operation, the fluid outlet dispenses the purified water. Water purification system according to the present disclosure may additionally include a waste outlet that is separate from the fluid outlet. The waste outlet may be downstream of the bacterial filter, and the system may include one or more diverter valves positioned to direct the cleaning fluid used to clean the bacterial filter to the waste outlet without allowing the cleaning fluid to pass through the fluid outlet.

[0013] In yet another aspect, the present disclosure provides a method of cleaning a bacterial filter, where the bacterial filter is in a water purification system. The method includes contacting a side of the bacterial filter that faces unsterilized water with a cleaning fluid for a sufficient length of time that at least 95%, such as at least 99%, at least 99.9%, or at least 99.99%, of the bacteria are rendered inactive. In some examples, the method includes contacting a side of the bacterial filter that faces unsterilized water with a cleaning fluid for a total period of time that is at least 2 minutes in length when the ORP of the cleaning fluid is at least 650 mV.

[0014] The water purification system may be in fluid communication with an inlet of a beverage dispensing system, an ice machine, or a non-potable water dispensing system, such as a water supply system for a laundry machine.BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0015] Examples according to the present disclosure will now be described, by way of example only, with reference to the attached Figures. To easily identify the discussion of any particular element or act, the most significant digit or digits in a reference number refer to the figure number in which that element is first introduced.

[0016] FIG. 1 illustrates an exemplary water purification system according to the present disclosure.

[0017] FIG. 2 illustrates another exemplary water purification system according to the present disclosure.

[0018] FIG. 3 illustrates an exemplary method according to the present disclosure.

[0019] FIG. 4 illustrates another exemplary method according to the present disclosure.

[0020] FIG. 5 is a flow diagram of Comparative Example 1 , illustrating a beverage dispenser connected to a municipal water source.

[0021] FIG. 6 is a flow diagram of Example 1, illustrating an exemplary water purification system according to the present disclosure connecting the beverage dispenser to the municipal water source.

[0022] FIG. 7 is a flow diagram of Comparative Example 2, illustrating an ice machine connected to a municipal water source.

[0023] FIG. 8 is a flow diagram of Example 2, illustrating an exemplary water purification system according to the present disclosure connecting the ice machine to the municipal water source.TERMS AND DEFINITIONS

[0024] In the context of the present disclosure, the term “bacterial filter” refers to a filter that removes bacterial content from a liquid. Some bacterial filters may meet NSF / ANSI 42 and / or NSF / ANSI 53 standards. Some bacterial filters are capable of passing the sterilization test described in ASTM F838-05, Standard Test Method for Determining Bacterial Retention of Membrane Filters Utilized for Liquid Filtration. In some examples according to the present disclosure, bacterial filters remove bacterial content from a liquid without separating salts from water molecules. In some examples according to the present disclosure, the bacterial filter is not a reverse osmosis filter, which typically removes particles 0.2 nm (0.0002 microns) or larger. Bacterial filters according to the present disclosure may include a filter membrane, a carbon filter, carbon composite media, or other material. The bacterial filter may be a micron or submicron filter, such as a filter with an average pore size that is from about 0.2 microns to about 10 microns, such as a 0.2 micron filter, a 0.5 micron filter, or a 5 micron filter. The pore size may be defined by a membrane or by a matrix of material.

[0025] In the context of the present disclosure, the term "cleaning fluid" refers to a fluid that kills or inactivates at least some microorganisms on a surface of an article or in a fluid. A cleaning fluid may be a sanitizing fluid, a disinfecting fluid, or a sterilizing fluid. The fraction of microorganisms that are killed or inactivated depends on the strength of the cleaning fluid and the length of time that the surface of the article or the fluid is in contact with the cleaning fluid. A cleaning fluid may have an oxidationreduction potential (ORP) of at least 450 mV, such as an ORP of at least 600 mV, at least 800 mV, or at least 1000 mV. In some examples, the cleaning fluid may include ozonated water; in other examples, the cleaning fluid may include an oxidizing agent, such as sodium hypochlorite, hydrogen peroxide, or peroxyacetic acid. When the cleaning fluid is ozonated water, the source of the ozonated water may be an ozone generator in fluid communication with a source of water, preferably an electrolytic ozone generator.

[0026] In the context of the present disclosure, the term “ozone generator” refers to a device or system that generates ozone in, or for mixing with, an aqueous liquid in sufficient quantities to result in a cleaning fluid, such as an ozonated liquid having an ORP of at least 450 mV, such as an ORP of at least 600 mV, at least 800 mV, or at least 1000 mV. Ozone generators according to the present disclosure may include an electrolytic ozone generator; an ozone gas generator, for example a corona discharge type ozone gas generator; a holding tank-less water ozonating system as described in WO2011038489 or WO2012058774; a UV light source configured to irradiate oxygen at a wavelength below 240 nm or below 200 nm, such as with a wavelength of about 185 nm, to produce ozone; or any combination thereof. The oxygen may be provided as substantially pure oxygen, such as at least 95% pure oxygen, or as air, preferably dry air. The generated ozone gas may be mixed with the liquid to produce the cleaning fluid. Alternatively, the UV light can be used to create ozone in water from oxygen dissolved in the water. When the ozone generator is or includes an electrolytic ozone generator or an ozone gas generator, the system may include an acid-based cation-exchange resin in fluid communication with an inlet of the ozone generator, such as described in WO2013026159. Although UV-C light sources that irradiate water at wavelengths that inactivate bacteria in the water (for example at wavelengths from 254 nm to 285 nm), such light sources do not generate ozone in the water in sufficient amounts to produce a cleaning fluid.DETAILED DESCRIPTION

[0027] Bacterial filters in a water purification system are often characterized as having a “contaminated” or “dirty” side facing the incoming water to be filtered, and a “clean” side facing downstream of the filter. If biological contaminants from the dirty side breach the bacterial filter and reach the clean side, the water purification system would then provide contaminated water downstream of the filter. Generally, the present disclosure provides water purification systems, and sub-systems of water purification systems, that supply a cleaning fluid to a side of a bacterial filter that faces the incoming water to be filtered, which may also be referred to as “unsterilized water”. The present disclosure may equally refer to the cleaning fluid as being supplied to the contaminated side, the dirty side, or the upstream side of the bacterial filter.

[0028] Systems, sub-systems, devices, and methods according to the presently disclosure may help reduce or prevent the incidence of biological contamination of the water purification system, such as over the lifetime of the bacterial filter; or may help extend the lifetime of the bacterial filter, such as if the bacterial filter is replaced every time the system dispenses contaminated water.

[0029] Systems, sub-systems, devices, and methods according to the presently disclosure may accept water directly or indirectly from a municipal or private water source. Examples of a private water source include ground water sources, such as wells; cisterns; springs; and streams. The accepted water may have a level of biological contamination of one colony forming unit per 100 milliliters of water (i.e. 1 CFU / 100 mL) or greater.

[0030] As noted above, in water purification systems discussed herein, during operation, the fluid outlet dispenses the purified water. Water purification system according to the present disclosure may additionally include a waste outlet that is separate from the fluid outlet. The waste outlet may be downstream of the bacterial filter, and the system may include one or more diverter valves positioned to direct the cleaning fluid used to clean the bacterial filter to the waste outlet without allowing the cleaning fluid to pass through the fluid outlet.

[0031] In one aspect, the present disclosure provides a water purification system that includes a water inlet, a bacterial filter downstream of the water inlet, a fluid outlet downstream of the bacterial filter, and a source of a cleaning fluid in fluid communication with an inlet of the bacterial filter to provide the cleaning fluid upstream of the bacterial filter. The system may also include a waste outlet that is separate from the fluid outlet.

[0032] It should be understood that, in the context of the present disclosure, the term “source of cleaning fluid” refers to a source in relation to the bacterial filter, rather than a source of cleaning fluid for the water purification system as a whole. For example, an ozone generator may accept water and generate, in situ, a cleaning fluid. The ozone generator may, in that situation, be a part of the source of cleaning fluid for the bacterial filter. In another example, a source of concentrated oxidizing agent may provide the concentrated oxidizing agent to a mixer that also accepts water and generates a cleaningfluid. In that situation, the mixer and the source of concentrated oxidizing agent may be a part of the source of cleaning fluid for the bacterial filter. It should also be understood that, in the context of the present disclosure, the term “source of cleaning fluid” refers to a component, or combination of components, that is able to generate the cleaning fluid. For example, an ozone generator would still be considered a source of cleaning fluid even though the ozone generator can only produce ozonated water when the ozone generator accepts water. In another example, a fluid mixer and a container intended to hold the oxidizing agent would still be considered a source of cleaning fluid even when the container did not hold any oxidizing agent.

[0033] The source of the cleaning fluid may be in fluid communication with the inlet of the bacterial filter when the water purification system is in a cleaning arrangement. The water purification system may be switched from the cleaning arrangement to a dispensing arrangement by closing off the fluid connection between the source of the cleaning fluid and the inlet of the bacterial filter, such as by a fluid switch. Alternatively, the water purification system may be switched from the cleaning arrangement to a dispensing arrangement by stopping the source of cleaning fluid from dispensing the cleaning fluid. In such an system, the source of the cleaning fluid may still be in fluid communication with the inlet of the bacterial filter when the water purification system is in the dispensing arrangement, even though no cleaning fluid is being provided to the bacterial filter.

[0034] The cleaning fluid may be a sanitizing fluid, a disinfecting fluid, or a sterilizing fluid. The cleaning fluid may have an oxidation-reduction potential (ORP) of at least 450 mV, such as an ORP of at least 600 mV, at least 800 mV, or at least 1000 mV. The cleaning fluid may include ozonated water, an oxidizing agent, such as sodium hypochlorite, hydrogen peroxide, or peroxyacetic acid, or any combination thereof. The ozonated water may be supplied by an ozone generator that is in fluid communication with a source of water. The water supplied to the ozone generator may be from the same source of water that is supplied to the bacterial filter.

[0035] The source of the cleaning fluid may be configured to provide the cleaning fluid to a side of the bacterial filter that faces unsterilized water.

[0036] The water purification system may include a single source of a cleaning fluid and may be configured to provide the cleaning fluid upstream of the bacterial filter and downstream of the bacterial filter. Alternatively, the water purification system may include a first source of a cleaning fluid configured to provide the cleaning fluid upstream of the bacterial filter, and a second source of a cleaning fluid configured to provide the cleaning fluid downstream of the bacterial filter. The first and the second sources of cleaning fluid may be different, may be configured to provide cleaning fluids at different ORP levels, and / or may be configured to provide cleaning fluid for different lengths of time.

[0037] The source of the cleaning fluid may be in fluid communication with the fluid outlet of the water purification system to provide the cleaning fluid downstream of the bacterial filter. The source of the cleaning fluid may be configured to provide the cleaning fluid to the fluid outlet of the water purification system when the water purification system is in a dispensing arrangement. In such an arrangement, the system may provide a low-strength cleaning fluid, such as a cleaning fluid having an ORP of from about 450 to about 750 mV, for a sufficient period of time while the system is dispensing the purified water to clean or sanitize the fluid flow path downstream from the bacterial filter. Since a bacterial filter is expected to remove substantially all of the bacteria (for example, at least 99.95% of the bacteria) from the unsterilized water accepted by the purification system, the low-strength cleaning fluid is provided: to kill the small number of bacteria that do pass through the bacterial filter; to reduce the growth of biofilm in the fluid flow path downstream from the bacterial filter; to prevent the bacteria from forming biofilm in the fluid flow path downstream from the bacterial filter; or any combination thereof.

[0038] In an exemplary system according to the present disclosure, the water purification system may include a first fluid flow path connecting the water inlet to the bacterial filter, the bacterial filter to the source the cleaning fluid, and the source of the cleaning fluid to the fluid outlet; and a second fluid flow path connecting the water inlet to the source of the cleaning fluid, the source of the cleaning fluid to the inlet of the bacterial filter and to an outlet of the bacterial filter, and the bacterial filter to at least one waste outlet.

[0039] The fluid outlet of a water purification system according to the present disclosure may be in fluid communication with a system or device that accepts purified water, such as a beverage dispensing system, an ice machine, a whole-house water system, a coffee machine, a vegetable washing system, or a non-potable water dispensing system, such as a water supply system for a laundry machine or for steam equipment.

[0040] The beverage dispensing system may include: an inlet in fluid communication with the fluid outlet of a water purification system according to the present disclosure; an ingredient container for storing a beverage ingredient; an ingredient supply tube connected to the ingredient container for supplying the beverage ingredient; optionally a carbon dioxide tank for storing and supplying carbon dioxide gas; optionally a mixing tub for mixing the water supplied from the water purification system and the carbon dioxide supplied from the carbon dioxide tank to produce carbonated water; a discharge pump for discharging the beverage ingredient; a dispensing valve opened by the action of a dispensing lever for discharging the water supplied from the water purification system or the carbonated water in the mixing tub, and the beverage ingredient; and a dispensing nozzle for discharging the water or the carbonated water and the beverage ingredient into a cup.

[0041] In another aspect, the present disclosure provides a water purification system that includes one or more bacterial filters, and a source of a cleaning fluid upstream of at least one of the bacterial filters, preferably upstream of all of the bacterial filters. The system may also include a waste outlet configured to dispense the used cleaning fluid, where the waste outlet is separate from a fluid outlet that is configured to dispense the filtered water.

[0042] The source of the cleaning fluid may be configured to provide the cleaning fluid to a side of the most upstream bacterial filter that faces unsterilized water.

[0043] The source of the cleaning fluid upstream of the bacterial filters may be configured to provide the cleaning fluid when the water purification system is in a cleaning arrangement, and optionally also in a dispensing arrangement. The water purification system may be switched from the cleaning arrangement to a dispensing arrangement, as discussed above.

[0044] The water purification system may include a source of a cleaning fluid downstream of all of the bacterial filters. The source of the cleaning fluid downstream of the bacterial filters may provide the cleaning fluid when the water purification system is in a dispensing arrangement.

[0045] The water purification system may include a single source of a cleaning fluid, or first and second sources of cleaning fluid, as discussed above, for example to provide cleaning fluid when the water purification system is in a dispensing arrangement.

[0046] In yet another aspect, the present disclosure provides a source of cleaning fluid in fluid communication with a side of a bacterial filter in a water purification system, where the side of the bacterial filter faces unsterilized water. The bacterial filter may be the most upstream bacterial filter in the water purification system. The water purification system may also include a waste outlet that dispense the used cleaning fluid, where the waste outlet is separate from a fluid outlet that dispenses the filtered water.

[0047] The source of the cleaning fluid may be in fluid communication with the side of the bacterial filter that faces unsterilized water when the water purification system is in a cleaning arrangement. The source of the cleaning fluid may be in fluid communication with the water purification system downstream of the bacterial filter, for example when the water purification is in a dispensing arrangement. Water purification systems that include the source of the cleaning fluid may be switched from the cleaning arrangement to a dispensing arrangement, as discussed above.

[0048] In still another aspect, the present disclosure provides a flow path in a water purification system, the flow path includes a water supply conduit fluidly connecting a source of cleaning fluid to a bacterial filter, the water supply conduit supplying a cleaning fluid to a side of the bacterial filter that faces unsterilized water. The water purification system may also include a waste outlet configured to dispense the used cleaning fluid, where the waste outlet is separate from a fluid outlet that is configured to dispense the filtered water.

[0049] Supplying the cleaning fluid to the side of the bacterial filter that faces unsterilized water may include supplying the cleaning fluid to an inlet of the bacterial filter that is fluidly connected to a source of unsterilized water.

[0050] The water supply conduit may fluidly connect the source of cleaning fluid to the bacterial filter, and preferably to a waste outlet, when the water purification system is in a cleaning arrangement. The conduit may include a fluid switch to, as discussed above, close off the fluid connection between the source of the cleaning fluid and the bacterial filter. In such an system, the conduit does not fluidly connect the source of the cleaning fluid and the bacterial filter when the water purification system is not in a cleaning arrangement, for example in a dispensing arrangement.

[0051] Alternatively, as discussed above, the water purification system may be switched from the cleaning arrangement to a dispensing arrangement by stopping the source of cleaning fluid from dispensing the cleaning fluid into the water supply conduit. In such an system, the water supply conduit may still fluidly connect the source of cleaning fluid to the bacterial filter when the water purification system is in the dispensing arrangement, even though no cleaning fluid is being provided to the bacterial filter.

[0052] In a further aspect, the present disclosure provides a method of cleaning a bacterial filter from a water purification system. The water purification system may be, for example, in fluid communication with an inlet of a beverage dispensing system. The method includes contacting a side of the bacterial filter that faces unsterilized water with a cleaning fluid for a sufficient length of time that at least 95%, such as at least 99%, at least 99.9%, or at least 99.99%, of the bacteria are rendered inactive.

[0053] In some examples, the method includes contacting a side of the bacterial filter that faces unsterilized water with a cleaning fluid for a total period of time that is at least 2 minutes, such as at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, or at least 10 minutes, in length when the ORP of the cleaning fluid is at least 650 mV, such as at least 800 mV or at least 1000 mV. It should be understood that, in the context of the present disclosure, the total period time may be provided by periods of time separated by flow through the bacterial filter without a cleaning fluid, where the period of time without treatment with cleaning fluid is less than 10 minutes. For example, a 2 minute period of contact time may be provided by flowing the cleaning fluid through bacterial filter for 1 minute, followed by flowing water through the bacterial filter for 30 seconds, followed by flowing more cleaning fluid through bacterial filter for 1 minute. In another example, a 2 minute period of contact time maybe provided by flowing the cleaning fluid through bacterial filter for 1.5 minutes, and letting the cleaning fluid contact the bacterial filter without substantive fluid flow for 30 seconds.

[0054] In specific examples, the method includes flowing an ozonated water having ozone at a concentration of about 2 to about 3 ppm, which results in an ORP value of about 1000 mV, through the bacterial filter for 3 minutes, backflushing the filter and manifold for 1 minute with the ozonated water, and flowing the ozonated water through the bacterial filter for another minute.

[0055] In other specific examples, the method includes flowing an ozonated water having ozone at a concentration of about 0.5 ppm, which results in an ORP value of about 750 mV, through the bacterial filter for 6 minutes, backflushing the filter for 2 minutes with the ozonated water, and flowing the ozonated water through the bacterial filter for 2 additional minutes.

[0056] Other exemplary methods according to the present disclosure include measuring the ORP value of the cleaning fluid upstream, such as immediately upstream, of the bacterial filter, and measuring the ORP value of the liquid downstream, such as immediately downstream, of the bacterial filter. In such exemplary methods, the bacterial filter may be contacted with the cleaning fluid while the downstream ORP value is lower than a desired threshold, and optionally for an additional period of time, such as an addition 30 seconds, or an additional 1, 2, 3, 4, or 5 minutes.

[0057] The desired threshold may be, for example, at least partially determined by the upstream ORP value, or may be a predetermined value. The desired threshold may be, for example, 80%, 90%, 95%, or 99% of the upstream ORP value. For example, if the upstream ORP value was 800 mV, the desired threshold may be 720 mV (i.e. 90% of 800 mV).

[0058] Although the predetermined value should be set to be lower than the upstream ORP value, the predetermined value may be independent of the upstream ORP value. For example, the cleaning fluid may have an ORP value of 900 mV and the bacterial filter may be contacted with the cleaning fluid until the downstream ORP value is determined to be at least 650 mV or at least 875 mV. This predetermined value may be reached more quickly by using a cleaning fluid with a greater ORP.

[0059] In some examples according to the present disclosure, the method includes contacting the bacterial filter with the cleaning fluid until the downstream ORP value is determined to be at least 650 mV plus for an additional 1 minute. In other examples, such as in methods used to inactivate at least a portion of any viruses present in the filter, the method may include contacting the bacterial filter with the cleaning fluid until the downstream ORP value is determined to be at least 875 mV plus for an additional 5 minutes.

[0060] In the context of the present disclosure, a location “immediately upstream” or “immediately downstream” of an element in a system refers to a location in the system where the ORP values of the cleaning solution are within 5% of each other. For example, if the ORP value of the cleaning solution is measured as 600 mV in one location, and the cleaning solution is at 580 mV as it flows into the inlet of the bacterial filter, that location would be considered to be immediately upstream of the inlet of the bacterial filter. Similarly, if the cleaning solution at the outlet of the bacterial filter is measured as 500 mV and is 490 mV at a location downstream of the bacterial filter, that location would be considered to be immediately downstream of the bacterial filter.

[0061] One example of a water purification system according to the present disclosure is illustrated in FIG. 1. The water purification system 100 includes an inlet (not shown) that accepts water from a water source 102. In a cleaning arrangement, the inlet is in fluid communication with a source of cleaning fluid 104, such as an ozone generator, to provide a cleaning fluid to a contaminated side of a bacterial filter 106. The cleaning fluid contacts the bacterial filter 106 and is discharged from a waste outlet (not shown) of the system as waste 108a.

[0062] In a dispensing arrangement, the inlet is in fluid communication with the bacterial filter 106 and dispensed the purified water from a system outlet (not shown) as purified water 110. Optionally, the system fluidly connects the source of cleaning fluid 104 to the system outlet. In such an optional configuration, the system 100 may provide cleaning fluid downstream of the bacterial filter 106, and / or may provide cleaning fluid to the downstream side of the bacterial filter 106.

[0063] In the illustrated water purification system 100, the illustrated fluid conduits may include sensors (not shown), fluid switches (for example solenoids) (not shown),and / or backflow preventers (not shown). For example: the fluid conduits 112 and 114 may include fluid switches to fluidly connect or disconnect the water source 102 to either, or both, of the source of cleaning fluid 104 and the bacterial filter 106; the fluid conduit 116 may include a fluid switch to fluidly connect or disconnect the source of cleaning fluid 104 to the contaminated side of the bacterial filter 106; and / or the optional fluid conduit 118 may include a fluid switch to fluidly connect or disconnect the source of cleaning fluid 104 to the downstream side of the bacterial filter 106. Backflow preventers may be included in the fluid conduits to direct the water flow in desired directions of flow.

[0064] Although the water purification system 100 illustrates the source of cleaning fluid 104 as having two separate outputs into conduits 116 and 118, it should be understood that the system could equally have only a single output from 104 that could then be split into different flow paths leading to the bacterial filter 106 and the downstream side of the bacterial filter 106.

[0065] In a cleaning arrangement, the fluid switch in conduit 114 may be closed, directing water through the source of cleaning fluid 104. The fluid switch in conduit 116 may be opened, and the system outlet (or a fluid switch leading to the system outlet) may be closed, directing cleaning fluid to the contaminated side of the bacterial filter 106, which may then be discharged from a waste outlet (not shown) as waste 108a. In a downstream-side cleaning arrangement, the fluid switch in conduit 118 may be opened, and the system outlet (or a fluid switch leading to the system outlet) may be closed, directing cleaning fluid to the downstream side of the bacterial filter 106, which may then be discharged from another waste outlet (not shown) as waste 108b.

[0066] In a flushing arrangement, for example performed after the bacterial filter 106 is cleaned, the fluid switches may be set to direct water through the source of cleaning fluid 104 via conduit 112, back into the bacterial filter 106 via fluid conduit 118, and discharged as waste 108b. In such an arrangement, the liquid provided by the source of cleaning fluid 104 may be different than the liquid provided in the cleaning arrangement. For example, the cleaning arrangement may provide a cleaning fluid with an ORP of 800 mV while the flushing arrangement may provide a sanitizing fluid, or a fluid that is not a cleaning fluid.

[0067] In a dispensing arrangement, the fluid switch in conduit 114 may be open and the fluid switch in conduit 112 may be closed, directing water through the bacterial filter 106, and dispensing the treated water as purified water 110. Optionally, the fluid switches in conduits 112 and 118 may also be open, directing water through the source of cleaning fluid 104 and downstream of the bacterial filter 106. In such an optional arrangement, cleaning fluid, such as a low-strength cleaning fluid, may be provided to the purified water being dispensed from the system.

[0068] The system illustrated in FIG. 1 may be modified to remove fluid conduit 114 and connect the water from the water source 102 to the bacterial filter 106 via the source of cleaning fluid 104, irrespective of whether the source of cleaning fluid 104 was producing cleaning fluid or not. In such an arrangement, the system may provide water from the water source to the bacterial filter with, or without, cleaning fluid depending on whether the source of cleaning fluid is creating cleaning fluid in, or dispensing cleaning fluid into, the water.

[0069] Another example of a water purification system according to the present disclosure is illustrated in FIG. 2. The water purification system 200 includes an inlet (not shown) that accepts water from a water source 202. In a cleaning arrangement, the inlet is in fluid communication with a source of cleaning fluid 204, such as an ozone generator, to provide a cleaning fluid to a contaminated side of a bacterial filter 206. The cleaning fluid contacts the bacterial filter 206 and is discharged from the system as waste 208a.

[0070] In a dispensing arrangement, the inlet is in fluid communication with the bacterial filter 206, the bacterial filter 206 is in fluid communication with the source of cleaning fluid 204, and the system dispenses the purified water from a system outlet (not show) as purified water 210. In such an arrangement, the source of cleaning fluid 204 may be off so that the system provides purified water. Alternatively, the source of cleaning fluid 204 may be operating to add cleaning fluid downstream of the bacterial filter 206. In such an arrangement, the purified water 210 may be dispensed as a low- strength cleaning fluid.

[0071] In the illustrated water purification system 200, the illustrated fluid conduits may include sensors (not shown), fluid switches (for example solenoids) (not shown),and / or backflow preventers (not shown). For example; the fluid conduits 212 and 214 may include fluid switches to fluidly connect or disconnect the water source 202 to either, or both, of the source of cleaning fluid 204 and the bacterial filter 206; the fluid conduit 216 may include a fluid switch to fluidly connect or disconnect the source of cleaning fluid 204 to the contaminated side of the bacterial filter 206; the fluid conduit 220 may include a fluid switch to fluidly connect or disconnect the bacterial filter 206 to the inlet of the source of cleaning fluid 204; and / or the fluid conduit 222 may include a fluid switch to fluidly connect or disconnect the source of cleaning fluid 204 to the downstream side of the bacterial filter 206. Backflow preventers may be included in the fluid conduits to direct the water flow in desired directions of flow.

[0072] Although the water purification system 200 illustrates the source of cleaning fluid 204 as having two separate outputs into conduits 210 and 216, it should be understood that the system could equally have only a single output from 204 that could then be split into different flow paths leading to the bacterial filter 206 and the system outlet.

[0073] In a cleaning arrangement, the fluid switch in conduit 214 may be closed, directing water through the source of cleaning fluid 204. The fluid switch in conduit 216 may be open, and the fluid switches in conduits 220 and 222 may be closed, directing cleaning fluid to the contaminated side of the bacterial filter 206, which may then be discharged as waste 208a. In a downstream-side cleaning arrangement, the fluid switch in conduit 222 may be open, and the fluid switch in conduit 216 may be closed, directing cleaning fluid to the downstream side of the bacterial filter 206, which may then be discharged as waste 208b.

[0074] In an alternative cleaning arrangement, the fluid switches in conduits 214 and 222 may be closed, and the fluid switches in conduits 212, 216, 220, and 210 may be open. In this cleaning arrangement, the water purification system 200 may, at the same time, both direct cleaning fluid to the contaminated side of the bacterial filter 206 and dispense the cleaning fluid out of the system.

[0075] In a flushing arrangement, for example performed after the bacterial filter 206 is cleaned, the fluid switches may be set to direct water through the source of cleaning fluid 204 via conduit 212, back into the bacterial filter 206 via fluid conduit 216 or 222,and discharged as waste 208a or waste 208b. In such an arrangement, the liquid provided by the source of cleaning fluid 204 may be different than the liquid provided in the cleaning arrangement. For example, the cleaning arrangement may provide a cleaning fluid with an ORP of 800 mV while the flushing arrangement may provide a sanitizing fluid, or a fluid that is not a cleaning fluid.

[0076] In a dispensing arrangement, the fluid switch in conduit 214 may be open and the fluid switch in conduit 212 may be closed, directing water through the bacterial filter 206 and the source of cleaning fluid 204, and dispensing the treated water as purified water 210. In such an arrangement, the source of cleaning fluid 204 may be inactive and the system may dispense purified water. Alternatively, the source of cleaning fluid 204 may be active and a cleaning fluid, for example a low-strength cleaning fluid, may be dispensed from the system.

[0077] One example of a method according to the present disclosure is illustrated in FIG. 3. The method 300 includes: contacting a side of the bacterial filter that faces unsterilized water with a cleaning fluid (302); backwashing the bacterial filter with the cleaning fluid (304); and flowing additional unsterilized water through the bacterial filter (408) once at least 95% of the bacteria have been rendered inactive.

[0078] Another example of a method according to the present disclosure is illustrated in FIG. 4. The method 400 includes contacting a side of the bacterial filter that faces unsterilized water with a cleaning fluid (402); measuring an ORP value of the cleaning fluid upstream of the bacterial filter (404); measuring an ORP value of the solution downstream of the bacterial filter (406); optionally backwashing the bacterial filter with the cleaning fluid (408); and flowing unsterilized water through the bacterial filter (410) once the measured downstream ORP value reaches a desired threshold.

[0079] Comparable Example 1

[0080] A carbonated beverage dispenser, assembled in a standard configuration, included the following commercially-available components: a chiller; a carbonation unit; water and syrup lines; and a dispenser that included mixing valves. The beverage dispenser was installed to accept water that was pressurized in a pressure tank and filtered through a bacterial filter (Everpure i2000(2) Cartridge EV961222) having a 0.5 micron rating and meeting NSF Standards #42 (chlorine and particulate reduction) and#53 (reduction of health-related contaminants, such as Cryptosporidium), as illustrated in FIG. 5.

[0081] From March to December, 2023, water dispensed from the beverage dispenser routinely and consistently showed levels of Pseudomonas aeruginosa between 1-80 colony forming units (CFUs) per 250 mL of water, with an average of about 25 CFUs / 250 mL.

[0082] Example 1

[0083] The bacterial filter of Comparable Example 1 was removed and replaced with a combination inline electrolytic ozone generator, sediment filter, and 0.5 micron carbon block bacterial filter (“HDH-PREMIUM Under Sink” sold by HydroNovation), as illustrated in FIG. 6. The electrolytic ozone generator was capable of operating at the flow rate of the bacterial filter, and was capable of generating ozone at a concentration of up to 1.5 ppm. The combination ozone generator and bacterial filter (referred to herein as “iClean® Lines”) was installed downstream of the pressure-tank, and installed upstream of an inlet to the beverage dispenser.

[0084] The flow path of the iClean Lines combination ozone generator and bacterial filter corresponds to the flow path illustrated in FIG. 2 in that the fluid conduits can, in a normal operation configuration, be opened and closed so that water can flow from the pressure tank (corresponding to the water source 202) to the HydroNovation filter (corresponding to the bacterial filter 206) and then to the electrolytic ozone generator (corresponding to the source of cleaning fluid 204) via the sediment filter (not illustrated in FIG. 2), before being dispensed to the beverage dispenser (corresponding to purified water 210).

[0085] The fluid conduits can, in a cleaning configuration, be opened and closed so that water can flow from the pressure tank to the HydroNovation filter via the sediment filter and then to the electrolytic ozone generator before the ozonated water is delivered to an upstream side of the bacterial filter or to a downstream side of the bacterial filter, and ultimately disposed as a waste (corresponding to waste 208a and 208b, respectively).

[0086] During normal operation, the beverage dispenser was set to request water at a flow rate of about 1.1 liters per minute (1pm). The electrolytic ozone generator was setto deliver ozonated water to the beverage dispenser at a concentration of about 0.3 ppm to about 0.5 ppm ozone when the beverage dispenser requested the water.

[0087] The combination inline electrolytic ozone generator and ozone generator were also set to run a high concentration cleaning cycle once a day. In the cleaning cycle, ozonated water at 1.5 ppm (which corresponds to an ORP of about 950 to about 1000 mV) was produced by the ozone generator and run through the bacterial filter: (a) for about 1 minute in a forward direction, (b) for about 1 minute in a backward direction, and (c) for about 1 minute in a forward direction. It should be understood that “in a forward direction” refers to the direction of the flow rate of the water during normal dispensing operation, and that “in a backward direction” refers to the opposite direction.

[0088] After installation of the combination inline electrolytic ozone generator and bacterial filter, water dispensed from the beverage dispenser was tested over the course of about 6 months. The results are illustrated in Table 1:Table 1

[0089] The result from July 8, 2024 of 40 CFUs / 100 mL was due to improper cleaning of the dispenser nozzle by cleaning staff resulting in bacterial contamination of the dispensing nozzle.

[0090] Comparable Example 2

[0091] A commercial Indigo NXT ice machine, sold by Manitowoc Ice, was installed to accept water that was filtered through a bacterial filter (Everpure i2000(2) Cartridge EV961222) having a 0.5 micron rating and meeting NSF Standards #42 (chlorine and particulate reduction) and #53 (reduction of health-related contaminants, such as Cryptosporidium), and then ozonated with an inline electrolytic ozone generator, asillustrated in FIG. 7. The ice machine was set to request water at a flow at a rate of about 2.2 liters per minute (1pm), resulting in the ozone generator delivering ozonated water to an inlet of the ice machine at a concentration of about 0.3 to 0.5 ppm.

[0092] From March to December, 2023, ice produced by that ice machine routinely and consistently showed levels of Pseudomonas aeruginosa between 70-100 colony forming units (CFUs) per 250 mL of ice.

[0093] Example 2

[0094] The bacterial filter of Comparable Example 2 was removed and replaced with a combination inline electrolytic ozone generator, sediment filter, and 0.5 micron carbon block bacterial filter (“HDH-PREMIUM Under Sink” sold by HydroNovation), as illustrated in FIG. 8. The combination ozone generator and bacterial filter (“iClean® Lines”) was installed to provide filtered water to an inlet of the already-present inline ozone generator, referred to as the “original ozone generator” in FIG. 8.

[0095] As discussed above, the flow path of the iClean Lines combination ozone generator and bacterial filter corresponds to the flow path illustrated in FIG. 2 in that the fluid conduits can, in a normal operation configuration, be opened and closed so that water can flow from the pressure tank (corresponding to the water source 202) to the HydroNovation filter (corresponding to the bacterial filter 206) and then to the electrolytic ozone generator (corresponding to the source of cleaning fluid 204) via the sediment filter (not illustrated in FIG. 2), before being dispensed as purified water (corresponding to purified water 210) that can be boosted in ozone concentration by the original ozone generator.

[0096] The fluid conduits can, in a cleaning configuration, be opened and closed so that water can flow from the pressure tank to the HydroNovation filter via the sediment filter and then to the electrolytic ozone generator before the ozonated water is delivered to an upstream side of the bacterial filter or to a downstream side of the bacterial filter, and ultimately disposed as a waste (corresponding to waste 208a and 208b, respectively).

[0097] Since the combination inline electrolytic ozone generator, sediment filter, and electrolytic ozone generator were around 100 feet away from the ice machine, during normal operation, the electrolytic ozone generator was set to deliver ozonated water tothe original ozone generator at a concentration of about 0.3 ppm to about 0.5 ppm ozone, and the original ozone generator was set to deliver ozonated water to the ice machine at a concentration of about 1 ppm to about 1.5 ppm ozone.

[0098] The iClean Lines electrolytic ozone generator was also set to run a high concentration cleaning cycle once a day, as described in Example 1. Briefly, in the cleaning cycle, ozonated water at 1.5 ppm (about 950 to 1000 mV) was run through the filter: (a) for about 1 minute in a forward direction, (b) for about 1 minute in a backward direction, and (c) for about 1 minute in a forward direction. During the cleaning cycle, the ozonated water that was run through the filter was dispensed from a waste outlet without being delivered to the ice machine.

[0099] After installation of the upstream ozone generator, ice was tested over the course of about 6 months. The results are illustrated in Table 2:Table 2

[0100] In the preceding description, for purposes of explanation, numerous details are set forth in order to provide a thorough understanding of the examples. However, it will be apparent to one skilled in the art that these specific details are not required. Accordingly, what has been described is merely illustrative of the application of the described examples and numerous modifications and variations are possible in light of the above teachings.

[0101] Since the above description provides examples, it will be appreciated that modifications and variations can be effected to the particular examples by those of skill in the art. Accordingly, the scope of the claims should not be limited by the particularexamples set forth herein, but should be construed in a manner consistent with the specification as a whole.

Claims

AMENDED CLAIMS received by the International Bureau on 14 January 2026 (14.01 .2026)What is claimed is:

1. A water purification system comprising: a water inlet, a bacterial filter downstream of the water inlet, a fluid outlet downstream of the bacterial filter configured to dispense purified water, and a source of a cleaning fluid in fluid communication with an inlet of the bacterial filter to provide the cleaning fluid upstream of the bacterial filter, wherein the cleaning fluid has an oxidation-reduction potential (ORP) of at least 450 mV, and optionally at least one waste outlet configured to dispense the cleaning fluid, wherein the at least one waste outlet is separate from the fluid outlet.

2. The water purification system of claim 1, wherein the source of the cleaning fluid is in fluid communication with the inlet of the bacterial filter when the water purification system is in a cleaning arrangement.

3. The water purification system of claim 1 or 2, wherein the cleaning fluid has an ORP of at least 600 mV, at least 800 mV, or at least 1000 mV; and / or wherein the cleaning fluid comprises: ozonated water, wherein the source of the ozonated water is an ozone generator in fluid communication with a source of water, preferably wherein the ozone generator is an electrolytic ozone generator; or an oxidizing agent, such as sodium hypochlorite, hydrogen peroxide, or peroxyacetic acid.

4. The water purification system of any one of claims 1 to 3, wherein the bacterial filter removes bacterial content from the unsterilized water without separating salts from water molecules; preferably wherein the bacterial filter is not a reverse osmosis filter.

5. The water purification system of claim 4, wherein the bacterial filter comprises: a micron or sub-micron filter, such as a filter with an average pore size that is from about 0.2 microns to about 10 microns, such as a 0.2 micron filter, a 0.5 micron filter, or a 5 micron filter; and / or a carbon or carbon composite filter.

6. The water purification system of any one of claims 1 to 5, wherein the source of the cleaning fluid is configured to provide the cleaning fluid to a side of the bacterial filter that faces unsterilized water.

7. The water purification system of any one of claims 1 to 6, wherein the source of the cleaning fluid is in fluid communication with the fluid outlet of the water purification system to provide the cleaning fluid downstream of the bacterial filter.

8. The water purification system of claim 7, wherein the source of the cleaning fluid is configured to provide the cleaning fluid to the fluid outlet of the water purification system when the water purification system is in a dispensing arrangement.

9. The water purification system of claim 7, wherein the system comprises a single source of a cleaning fluid and is configured to provide the cleaning fluid upstream of the bacterial filter and downstream of the bacterial filter.

10. The water purification system of claim 7, wherein the system comprises a first source of a cleaning fluid configured to provide the cleaning fluid upstream of the bacterial filter, and a second source of a cleaning fluid configured to provide the cleaning fluid downstream of the bacterial filter.

11. The water purification system of any one of claims 1 to 9, wherein the system comprises: a first fluid flow path connecting: the water inlet to the bacterial filter, the bacterial filter to the source the cleaning fluid, and the source of the cleaning fluid to the fluid outlet; and a second fluid flow path connecting: the water inlet to the source of the cleaning fluid,the source of the cleaning fluid to the inlet of the bacterial filter and to an outlet of the bacterial filter, and the bacterial filter to the at least one waste outlet.

12. The water purification system of any one of claims 1 to 11, further comprising:(i) an ORP sensor upstream, such as immediately upstream, of the bacterial filter and downstream of the source of the cleaning fluid; and / or(ii) an ORP sensor downstream, such as immediately downstream, of the bacterial filter.

13. The water purification system of any one of claims 1 to 12, wherein the fluid outlet of the water purification system is in fluid communication with a beverage dispensing system, an ice machine, or a non-potable water dispensing system, such as a water supply system for a laundry machine.

14. The water purification system of claim 13, wherein the beverage dispensing system comprises: an inlet in fluid communication with the fluid outlet of the water purification system; an ingredient container for storing a beverage ingredient; an ingredient supply tube connected to the ingredient container for supplying the beverage ingredient; optionally a carbon dioxide tank for storing and supplying carbon dioxide gas; optionally a mixing tub for mixing the water supplied from the water purification system and the carbon dioxide supplied from the carbon dioxide tank to produce carbonated water; a discharge pump for discharging the beverage ingredient; a dispensing valve opened by the action of a dispensing lever for discharging the beverage ingredient and either the water supplied from the water purification system or the carbonated water in the mixing tub; and a dispensing nozzle for discharging the optionally-carbonated water and the beverage ingredient into a cup.

15. A water purification system comprising one or more bacterial filters, and a source of a cleaning fluid upstream of at least one of the bacterial filters, preferably upstream of all of the bacterial filters, wherein the cleaning fluid has an oxidation-reduction potential (ORP) of at least 450 mV; and optionally at least one waste outlet configured to dispense the cleaning fluid, wherein the at least one waste outlet is separate from a fluid outlet configured to dispense purified water.

16. The water purification system of claim 15, wherein the source of the cleaning fluid is configured to provide the cleaning fluid to a side of the most upstream bacterial filter that faces unsterilized water.

17. The water purification system of claim 15 or 16, wherein the source of the cleaning fluid upstream of the bacterial filters provides the cleaning fluid when the water purification system is in a cleaning arrangement.

18. The water purification system of any one of claims 15 to 17, further comprising a source of a cleaning fluid downstream of all of the bacterial filters.

19. The water purification system of claim 18, wherein the source of the cleaning fluid downstream of the bacterial filters provides the cleaning fluid when the water purification system is in a dispensing arrangement.

20. The water purification system of claim 18 or 19, wherein the system comprises a single source of a cleaning fluid and is configured to provide the cleaning fluid upstream of all of the bacterial filters and downstream of all of the bacterial filters.

21. The water purification system of claim 18 or 19, wherein the system comprises a first source of a cleaning fluid configured to provide the cleaning fluid upstream of all of the bacterial filters, and a second source of a cleaning fluid configured to provide the cleaning fluid downstream of all of the bacterial filters.

22. The water purification system of any one of claims 15 to 21, further comprising:(i) an ORP sensor upstream, such as immediately upstream, of the one or more bacterial filters, and downstream from the source of the cleaning fluid; and / or(ii) an ORP sensor downstream, such as immediately downstream, of the one or more bacterial filters.

23. The water purification system of any one of claims 15 to 22, wherein the cleaning fluid comprises: ozonated water, wherein the source of the ozonated water is an ozone generator in fluid communication with a source of water, preferably wherein the ozone generator is an electrolytic ozone generator; or an oxidizing agent, such as sodium hypochlorite, hydrogen peroxide, or peroxyacetic acid.

24. The water purification system of any one of claims 15 to 23, wherein the one or more bacterial filters remove bacterial content from the unsterilized water without separating salts from water molecules; preferably wherein the bacterial filter is not a reverse osmosis filter.

25. The water purification system of claim 24, wherein the one or more bacterial filters are each, independently: a micron or sub-micron filter, such as a filter with an average pore size that is from about 0.2 microns to about 10 microns, such as a 0.2 micron filter, a 0.5 micron filter, or a 5 micron filter; and / or a carbon or carbon composite filter.

26. A source of cleaning fluid in fluid communication with a side of a bacterial filter in a water purification system, wherein the side of the bacterial filter faces unsterilized water, and wherein the cleaning fluid has an oxidation-reduction potential (ORP) of at least 450 mV, optionally wherein the bacterial filter is the most upstream bacterial filter in the water purification system; and optionally wherein the water purification system includes at least one waste outlet configured to dispense the cleaning fluid, wherein the at least one waste outlet is separate from a fluid outlet configured to dispense purified water.

27. The source of cleaning fluid of claim 26, wherein the source of the cleaning fluid is in fluid communication with the side of a bacterial filter that faces unsterilized water when the water purification system is in a cleaning arrangement.

28. The source of cleaning fluid of claim 26 or 27, wherein the source of the cleaning fluid is additionally in fluid communication with the water purification system downstream of the bacterial filter.

29. The source of cleaning fluid of claim 28, wherein the source of the cleaning fluid is in fluid communication with the water purification system downstream of the bacterial filter when the water purification is in a dispensing arrangement.

30. The source of cleaning fluid of any one of claims 26 to 29, wherein the cleaning fluid comprises: ozonated water, wherein the source of the ozonated water is an ozone generator in fluid communication with a source of water, preferably wherein the ozone generator is an electrolytic ozone generator; or an oxidizing agent, such as sodium hypochlorite, hydrogen peroxide, or peroxyacetic acid.

31. The source of cleaning fluid of any one of claims 26 to 30, wherein the bacterial filter removes bacterial content from the unsterilized water without separating salts from water molecules; preferably wherein the bacterial filter is not a reverse osmosis filter.

32. The source of cleaning fluid of claim 31, wherein the bacterial filter is: a micron or sub-micron filter, such as a filter with an average pore size that is from about 0.2 microns to about 10 microns, such as a 0.2 micron filter, a 0.5 micron filter, or a 5 micron filter; and / or a carbon or carbon composite filter.

33. A flow path in a water purification system, the flow path comprising: a water supply conduit fluidly connecting a source of cleaning fluid to a bacterial filter, the water supply conduit supplying a cleaning fluid to a side of the bacterial filterthat faces unsterilized water, wherein the cleaning fluid has an oxidation-reduction potential (ORP) of at least 450 mV; optionally wherein the water purification system includes at least one waste outlet in fluid communication with the water supply conduit and configured to dispense the cleaning fluid, wherein the at least one waste outlet is separate from a fluid outlet configured to dispense purified water.

34. The flow path of claim 33, wherein supplying the cleaning fluid to the side of the bacterial filter that faces unsterilized water comprises supplying the cleaning fluid to an inlet of the bacterial filter that is fluidly connected to a source of unsterilized water.

35. The flow path of claim 33 or 34, wherein the water supply conduit fluidly connects the source of cleaning fluid to the bacterial filter when the water purification system is in a cleaning arrangement.

36. The flow path of any one of claims 33 to 35, where the flow path comprises an ORP sensor upstream, such as immediately upstream, of the bacterial filter.

37. The flow path of any one of claims 33 to 36, wherein the cleaning fluid comprises: ozonated water, wherein the source of the ozonated water is an ozone generator in fluid communication with a source of water, preferably wherein the ozone generator is an electrolytic ozone generator; or an oxidizing agent, such as sodium hypochlorite, hydrogen peroxide, or peroxyacetic acid.

38. The flow path of any one of claims 33 to 37, wherein the bacterial filter removes bacterial content from the unsterilized water without separating salts from water molecules; preferably wherein the bacterial filter is not a reverse osmosis filter.

39. The flow path of claim 38, wherein the bacterial filter is: a micron or sub-micron filter, such as a filter with an average pore size that is from about 0.2 microns to about 10 microns, such as a 0.2 micron filter, a 0.5 micron filter, or a 5 micron filter; and / or a carbon or carbon composite filter.

40. A method of cleaning a bacterial filter, wherein the bacterial filter is in a water purification system, preferably wherein the water purification system is in fluid communication with an inlet of a beverage dispensing system, the method comprises: contacting a side of the bacterial filter that faces unsterilized water with a cleaning fluid that has an oxidation-reduction potential (ORP) of at least 450 mV for a sufficient length of time that at least 95%, such as at least 99%, at least 99.9%, or at least 99.99%, of the bacteria are rendered inactive, or for a period of time that is at least 2 minutes, such as at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, or at least 10 minutes, in length when the ORP of the cleaning fluid is at least 650 mV, such as at least 800 mV, at least 875 mV, or at least 1000 mV.

41. The method of claim 40, further comprising flushing the bacterial filter with the cleaning fluid.

42. The method of claim 40, wherein contacting the side of the bacterial filter that faces unsterilized water with the source of cleaning fluid comprises: flowing an ozonated water having ozone at a concentration of about 2 to about 3 ppm through the bacterial filter for 3 minutes, backflushing the filter for 1 minute with the ozonated water, and flowing the ozonated water through the bacterial filter for another minute.

43. The method of claim 40, wherein contacting the side of the bacterial filter that faces unsterilized water with the source of cleaning fluid comprises: flowing an ozonated water having ozone at a concentration of about 0.5 ppm through the bacterial filter for 6 minutes, backflushing the filter for 2 minutes with the ozonated water, and flowing the ozonated water through the bacterial filter for 2 additional minutes.

44. The method of claim 40 or 41, wherein contacting the side of the bacterial filter that faces unsterilized water with the source of cleaning fluid comprises: measuring an ORP value of the cleaning fluid upstream, such as immediately upstream, of the bacterial filter;measuring an ORP value of the liquid downstream, such as immediately downstream, of the bacterial filter; and flowing unsterilized water through the bacterial filter (408) once the measured downstream ORP value reaches a desired threshold.

45. The method of any one of claims 40 to 44, wherein the cleaning fluid comprises: ozonated water, wherein the source of the ozonated water is an ozone generator in fluid communication with a source of water, preferably wherein the ozone generator is an electrolytic ozone generator; or an oxidizing agent, such as sodium hypochlorite, hydrogen peroxide, or peroxyacetic acid.

46. The method of any one of claims 40 to 45, wherein the bacterial filter, during operation, removes bacterial content from the unsterilized water without separating salts from water molecules; preferably wherein the bacterial filter is not a reverse osmosis filter.

47. The method of claim 46, wherein the bacterial filter is: a micron or sub-micron filter, such as a filter with an average pore size that is from about 0.2 microns to about 10 microns, such as a 0.2 micron filter, a 0.5 micron filter, or a 5 micron filter; and / or a carbon or carbon composite filter.

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