WO2008071969A1

WO2008071969A1 - A water treatment system comprising an electrochemical ion generator

Info

Publication number: WO2008071969A1
Application number: PCT/GB2007/004776
Authority: WO
Inventors: Christian J. Gauthier
Original assignee: Walker, Ross, Thomson
Priority date: 2006-12-14
Filing date: 2007-12-13
Publication date: 2008-06-19
Also published as: GB0625000D0

Abstract

A water treatment system comprising an ion generator for introducing ions into a water supply, wherein the ion generator communicates with a regulator which regulates the amount of ions introduced by way of the ion generator into the water supply based on water usage.

Description

A WATER TREATMENT SYSTEM COMPRISING AN ELECTROCHEMICAL ION GENERATOR

Description of Invention

The present invention relates to a fluid treatment system. In particular, the present invention relates to a fluid treatment system, which, in use, treats a fluid such as a liquid, in particular, water. More particularly, the present invention relates to a water treatment system comprising an ion generator and process for treating contaminated water by introducing ions into a flow of water or a water supply or a water source.

Legionnaires' disease is a type of pneumonia. It was named after an outbreak of severe pneumonia, which affected a convention of the American

Legionnaires in 1976. One of the most common species of bacteria which causes Legionnaires disease is called Legionella pneumophila. People can contract Legionnaires disease by inhaling small droplets of water suspended in the air, which contain the legionella bacterium. This bacterium is widespread in nature and it mainly lives in water, for example, ponds, where it does not usually cause problems. Outbreaks of Legionnaires disease occur from purpose built water systems where temperatures are warm enough to encourage growth of the bacteria, e.g. in cooling towers, evaporative condensers and whirlpool spas, and from water used for domestic purposes in cruise ships and buildings such as hotels, hospitals, nursing homes and office buildings and the like. Other water borne bacteria can also cause infections, in particular, lung infections, such as pseudomonas bacteria.

Pontiac fever, a flu-like illness caused by the bacterium Legionella pneumophila contracted by breathing mist that comes from a water source

(such as air conditioning cooling towers, whirlpool spas, showers) contaminated with the bacteria. The incubation period is short, from a few hours to 2 days, before the onset of fever and muscle aches. Persons with Pontiac fever do not have pneumonia. They generally recover in 2 to 5 days without treatment. Pontiac fever is so-named because of an outbreak in 1968 in Pontiac, Michigan. It is a milder form of legionellosis than Legionnaire disease which is caused by the same bacterium

With a view to suppressing growth of and/or eradicating micro-organisms, for example, water borne bacteria such as Legionella from a supply of water or biofilm, which has built up on an internal surface of a water supply network, it is known to expose the water and/or biofilm to ions; said ions being induced by metallic electrodes, which are part of an ion generator.

Biofilms are usually found on solid substrates, e.g. metals, plastics, soil particles, medical implant materials, and tissue, submerged in or exposed to some aqueous solution, although biofilms can form as floating mats on liquid surfaces. Essentially, biofilm may form on any surface exposed to bacteria and some amount of water. Given sufficient resources for growth, a biofilm will quickly grow to be macroscopic. Biofilms can contain many different types of microorganism, e.g. bacteria, archaea, protozoa and algae; each group performing specialized metabolic functions. However, some organisms will form biofilms comprising a single species under certain conditions. Biofilm is generally held together and protected by a matrix of excreted polymeric compounds called EPS (EPS is an abbreviation for either extracellular polymeric substance or exopolysaccharide). This matrix protects the cells within it and facilitates communication between the cells through biochemical signals. Some biofilms have been found to contain water channels that help distribute nutrients and signaling molecules. This matrix is strong enough that, under certain conditions, biofilms can become fossilized. Bacteria living in a biofilm usually have significantly different properties from free-floating bacteria of the same species, as the dense and protected environment of the film allows them to cooperate and interact in various ways. Once anchored to a surface, biofilm microorganisms carry out a variety of detrimental or beneficial reactions (by human standards), depending on the surrounding environmental conditions. One benefit of a biofilm environment for the constituent microorganisms is increased resistance to detergents and antibiotics, as the dense extracellular matrix and the outer layer of cells protect the interior of the community. In some cases antibiotic resistance of bacteria contained within a biofilm matrix can be increased one thousand fold in comparison with microorganisms not within such a matrix.

Ion generators generally include at least a pair of electrodes, for example, a pair of pure copper and/or sliver electrodes, or alloys thereof, which, in use, create positive metallic ions when a DC current is passed between such electrodes. The resultant metallic ions, for example, Cu²⁺ and Ag⁺, are released from the positive electrode and are attracted to the other, negatively charged electrode. As will be appreciated, the water flowing between the electrodes will carry the .positive .metallic ions away into the water system before they actually reach the opposite, negatively charged electrode. These positively charged ions, for example, positively charged copper and silver ions travelling within the water supply system can bind themselves to negatively charged micro-organisms such as Legionella, or other micro-organisms present in the water system, which may be potentially harmful to health. On binding, the positive metallic ions will instigate a multi-phase process, which will ultimately disrupt the overall cell metabolism of the micro-organism resulting in cell lysis, namely, cell death.

Therefore, and as will be appreciated, ion generators can suppress the growth of and/or eradicate micro-organisms from a water supply using safe levels of positive metallic ions they have generated; such levels being below the internationally prescribed guidelines for the level of metallic ions in water. It will be appreciated that the water usage in a building or buildings can vary over the course of a day. For example, in the morning, before people go to work, water usage will be higher in homes than when people are at work. This is evidenced by Figure 1 , which indicates the rate of water consumption (in L min^"1) at a healthcare facility over a four day period. As will be appreciated, Figure 1 indicates that, in this specific example, the rate of water consumption can vary from as low as 1.3 L min^"1, to as much as 6.9 L min^"1 during the course of a day.

With the above in mind, a drawback of previous ion generators is that they do not react to changing water usage due to changing water demand. In particular, one of the problems associated with previous ion generators is that when the water usage fluctuates the concentration of ions in the water also fluctuates. In particular, when water usage is high a water treatment system introducing a constant level of ions into the water may not introduce sufficientamounts of ions into the water supply to suppress the growth of and/or eradicate micro-organisms therefrom. On the other hand, when the water usage is low a water treatment system introducing a constant level of ions into the water may introduce excess amounts of ions into the water supply so that the concentration of ions in the water is above levels which are safe to mammalian health.

It is an object of the present invention to provide a water treatment system and process which at least addresses the problems identified above.

In a first aspect of the present invention there is provided a water treatment system comprising: an ion generator for introducing ions into a water supply, wherein the ion generator communicates with a regulator which regulates the amount of ions introduced by way of the ion generator into the water supply based on water usage.

As will be appreciated, because the water treatment system of the present 5 invention can generate differing amounts of ions dependant on water usage, the present invention can provide treated water with near constant ion concentrations, irrespective of the actuai water usage.

Preferably, the regulator regulates the amount of ions introduced by way of

10 the ion generator based on water flow rate. It is to be understood that the water flow rate is the actual rate of flow of water through the water treatment system. The water flow rate can be measured by the regulator and the amount of ions introduced can be regulated accordingly. Advantageously, the regulator is a water flow meter.

15

Further preferably, the concentration of ions in the treated water supply is

- ... . maintained at relatively constant levels, in the water output, wherein the concentration of ions is measured by a sensor. As will be appreciated the regulator may comprise a sensor, said sensor sensing the concentration of

20 ions in the water output. The sensor may be used as a real-time sensor of the concentration of ions and, therefore, the regulator may regulate the ion generator to react to high or low ion concentrations, which will be representative of water usage. Advantageously, the sensor is an ion concentration sensor.

25

Further preferably, the regulator regulates the amount of ions introduced by way of the ion generator based on anticipated water usage at different times. Advantageously, the regulator comprises a timer. It is to be understood that the water usage may fluctuate at different times. The regulator may comprise

30 a timer which is programmed to regulate the ion generator so that the ion generator introduces more ions at times predicted to have higher water flow rate, that is, based on anticipated water usage.

Preferably, the regulator comprises a safety flow switch. As will be 5 appreciated, at times when the water treatment system contains little or no water the electrodes may be damaged when they are turned on. The regulator may comprise a safety flow switch which regulates the water treatment system so that the water treatment system is turned immediately off at times of little or no water flow. 10

Advantageously, the ion generator comprises at least two arrays, each array comprising at least one chamber cell.

Further preferably, each array is associated with at least one valve, said at

15 least one valve regulating the flow of water through the array. As will be appreciated, the association of each array with at least one valve provides a

_ . . means ,of regulating the flow of water in or out of each array. Hence, the valves associated with each array provide the advantage in that each array may be isolated, thereby providing for even use of each array in a water

20 treatment system and minimising outperforming arrays. Furthermore, the isolation of each array allows for an array to be isolated, to allow for maintenance and/or cleaning, without the need to turn the ion generator off.

Preferably, the ion generator comprises two, three, four, five, six, seven, eight, 25 nine or ten arrays of chamber cells.

Preferably, each array comprises one, two, three, four, five, six, seven, eight, nine or ten chamber cells. Advantageously, each chamber cell comprises at least two electrodes wherein at least one of the electrodes produces ions. Preferably, the ions produced by the electrodes are metal ions. In this connection, it will be appreciated that the electrodes could be made from any metal or alloy which produces metal ions 5 some, non-limiting, examples of metal ions produced by the electrodes are copper ions, silver ions, gold ions, titanium ions and zinc ions.

Further preferably, the ions produced by the electrodes are Ag⁺ and/or Cu²⁺. Advantageously, in the water treated by the water treatment system, the 0 concentration of Cu²⁺ is preferably about 0.4 ppm above a predetermined background concentration and the concentration of Ag⁺ is preferably about 0.04 ppm above a predetermined background concentration.

Further preferably, each chamber cell is associated with at least one valve, 5 said at least one valve regulating the flow of water through the chamber cell.

_. . In a second aspect of the present invention, there is provided a method of treating a water supply comprising passing water through the water treatment system of the present invention. Preferably, the method of treating a water 0 supply is used to treat a mains water supply.

In a third aspect of the present invention, there is provided a kit for preparing a water treatment system of the present invention. 5 One, non-limiting, water treatment system and process in accordance with the present invention will now be described by way of reference to Figure 2, which illustrates a schematic diagram of one embodiment of a water treatment system of the present invention. As illustrated in Figure 2, a water treatment system (10) in accordance with the present invention is associated with an ion generator (11), said ion generator comprising two arrays, the first array being generally represented by the number (12) and the second array being generally represented by the number (13). In the preferred embodiment, each array comprises one Ag- Silver chamber cell (108) and five Cu-Copper chamber cells (109). Each chamber cell comprises two electrodes which can introduce ions, Ag⁺ (108) or Cu²⁺ (109), into a water supply. In particular, the chamber cells (108) and (109) may be of the type obtainable from ProCare Water Treatment Inc.

The water treatment system (10) is in communication with a mains water supply. The water from the water supply enters the water treatment system at position (14). The water may be treated by the water treatment system (10) and leaves at outlet (15).

The water treatment system (10) further comprises a regulator (101). In the preferred. embodiment, the regulator (101 ) comprises a management system . (102) attached to a power supply (107), in communication with the chamber cells (108) and (109). The management system (102) comprises a computational device (110) in communication with a water flow meter (105), said water flow meter measuring the water usage by monitoring the flow of water leaving the water treatment system (10) at outlet (15).

As will be appreciated, the water flow meter (105) communicates the relative flow of water to the computational device (110). Preferably, during periods of high flow rate, the computational device (110) switches on both the first array

(12) and the second array (13). Alternatively, during periods of low flow rate, the computational device (110) switches on only the first array (12) or the second array (13). Further preferably, during periods of high flow rate, the computational device (110) switches on more chamber cells (108) and/or (109) than at the times when the water flow meter (105) communicates relatively low water flow rate. Each array in the non-limiting embodiment illustrated by Figure 2 includes two valves (103) which, in communication with the management system (102) regulate the flow of water in and/or out of each array.

Figure 3 indicates the number of active chamber cells from the water treatment system indicated by Figure 2, and the array to which they belong, over the period of time indicated by Figure 1. It will be appreciated that Figure 3 indicates that at peak times of water usage the number of active chamber cells is greater than at times of relatively low water consumption. Figure 3 also indicates that, in order to preserve the components of the chamber cells, when only one array is in operation, the active chamber cells may be selected from the first array (12) at one time and from the second array (13) at another time. This selection of chamber cells from different arrays maintains even wearing of the electrodes and avoids the creation of outperforming arrays.

Each array in the non-limiting embodiment illustrated by Figure 2 includes one pump (104) which, in communication with the management system (102) can pump water in and/or out of each array.

Each array in the non-limiting embodiment illustrated by Figure 2 includes one safety flow switch (106) which, in communication with the management system (102), can turn the water treatment system (10) off when there is no water supply to the water treatment system (10) or when the amount of water entering at position (14) is small enough that if the water treatment system (10) was turned on it would be damaged. As will be appreciated, in an alternative embodiment of the present invention, the water flow meter (105) could be replaced by a different meter, for example an ion concentration meter, an ion concentration sensor or a timer.

Although the ion generator illustrated by Figure 2 is associated with two arrays, each array comprising 6 chamber cells, it is to be appreciated that there may be any number greater than one of arrays, each array connected in series and/or parallel, and each array containing at least one chamber cell connected in series and/or parallel, or combinations thereof. In preferred embodiments, the ion generator (11 ) comprises 2, 3, 4, 5, 6, 7, 8, 9 or 10 arrays. Each array in the preferred embodiments comprises at least one chamber cell (108) and/or (109); preferably 1 , 2, 3, 4, 5, 6, 7, 8, 9, or 10 chamber cells. In the preferred embodiments, each array with more that 1 chamber cell may have the chamber cells connected in series and/or parallel. Furthermore, in the preferred embodiments, the arrays may be connected in series and/or parallel.

It will be appreciated that each chamber cell within an array may be associated with a valve, the valve may be either open or closed, the valve being positioned before and/or after the entrance point of the water from the water mains supply into the chamber cell. In this regard, a valve associated with an individual chamber cell may isolate an individual chamber cell to prevent over use of one chamber cell and/or to allow cleaning of one or more chamber cells.

It will be appreciated that the mains supply may have an associated valve which, in communication with the management system, regulates the flow from position (14) into the water treatment system. It will be appreciated that the water treatment system may have an associated valve which, in communication with the management system, regulates the flow from the water treatment system at outlet (15).

The management system may be in communication with the valves, as described above. The management system may open or close the valves in response to the water usage.

When used in this specification and claims, the terms "comprises" and "comprising" and variations thereof mean that the specified features, steps or integers are included. The terms are not to be interpreted to exclude the presence of other features, steps or components.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

Claims:

1. A water treatment system comprising: an ion generator for introducing ions into a water supply, wherein the ion generator communicates with a regulator which regulates the amount of ions introduced by way of the ion generator into the water supply based on water usage.

2. A water treatment system according to Claim 1 wherein the regulator regulates the amount of ions introduced by way of the ion generator based on water flow rate.

3. A water treatment system according to Claim 2 wherein the regulator comprises a water flow meter.

4. A water treatment system according to any of the preceding claims wherein the concentration of ions in the treated water supply is maintained at relatively -constant levels owing to the regulator regulating the concentration of ions in the treated water supply.

5. A water treatment system according to Claim 4 wherein the regulator comprises an ion concentration sensor.

6. A water treatment system according to Claim 1 wherein the regulator regulates the amount of ions introduced by way of the ion generator based on anticipated water usage at different times.

7. A water treatment system according to Claim 6 wherein the regulator comprises a timer.

8. A water treatment system according to any of the preceding claims wherein the regulator comprises a safety flow switch.

9. A water treatment system according to any of the preceding claims wherein the ion generator comprises at least two arrays, each array comprising at least one chamber cell.

10. A water treatment system according to any of the preceding claims wherein each array is associated with at least one valve, said at least one valve regulating the flow of water through the array.

11. A water treatment system according to Claim 8 wherein the ion generator comprises two, three, four, five, six, seven, eight, nine or ten arrays of chamber cells.

12. A water treatment system according to Claim 11 wherein each array comprises one, two, three, four, five,, six, seven, eight, nine^or ten. chamber cells.

13. A water treatment system according to any of the preceding claims wherein each chamber cell comprises at least two electrodes wherein at least one of the electrodes produces ions.

14. A water treatment system according to any of the preceding claims wherein the ions produced by the electrodes are metal ions.

15. A water treatment system according to any of the preceding claims wherein the ions produced by the electrodes are Ag⁺ and/or Cu²⁺.

16. A water treatment system according to Claim 15 wherein the concentration of Cu²⁺ in the treated water is preferably about 0.4 ppm above a predetermined background concentration and the concentration of Ag⁺ in the treated water is preferably about 0.04 ppm above a predetermined background concentration.

17. A water treatment system according to any of the preceding claims wherein each chamber cell is associated with at least one valve, said at least one valve regulating the flow of water through the chamber cell.

18. A method of treating a water supply comprising passing water through a water treatment system as claimed by any one of the preceding claims.

19. A method of treating a water supply according to Claim 18 wherein the water supply is a mains water supply.

20.- A kit for preparing a watertreatment system according to any of the- preceding claims.

21. A water treatment system as claimed in any of the preceding claims as hereinbefore described.

22. A water treatment system substantially as hereinbefore described by way of reference to the figures.

23. A method of treating water substantially as hereinbefore described by way of reference to the figures.