Systems and methods for purified water having reduced ionic and organic contaminants

Abstract

Contacting (i) an input water and (ii) an ion-exchange medium and exchanging anions and cations from an input water with hydroxide and hydronium ions respectively so as to give rise to a first water; contacting (i) the first water and a (ii) carbonaceous medium under conditions to remove at least one organic species from the first water so as to give rise to second water; and exchanging anions from the second water with hydroxide ions.

Description

SYSTEMS AND METHODS FOR PURIFIED WATERHAVING REDUCED IONIC AND ORGANIC CONTAMINANTSRELATED APPLICATIONS

[0001] The present application claims priority to and the benefit of United States patent application no. 63 / 518,983, “Systems And Methods For Purified Water Having Reduced Ionic And Organic Contaminants’’ (filed August 11, 2023). All foregoing applications are incorporated herein by reference in their entireties for any and all purposes.TECHNICAL FIELD

[0002] The present disclosure relates to the field of water purification systems and methods.BACKGROUND

[0003] Laboratory water purification is a mature technique for generating the water required in the laboratory for multitude of applications such as preparing solutions, reagents, nutrients, eluents for chromatography, diluting sample standards for calibration and the like. The water generated by a standard lab water purifier system is expected to be free of ionic impurities. The pure water generated in most laboratory is denoted as Type 1 water with a resistivity of 18.2 MQ-cm. Some laboratory water purifiers achieve the desired foregoing purity value, but controlling the organic content of the water is a challenge and is not always wel 1 -characteri zed .

[0004] The typical approach in the prior art for addressing the organics is by a single pass through a UV detector at 185 nm and / or 254 nm. The bulk of the remaining organics are typically removed using a carbon bead or packing in a column configuration. Organics are typically termed as total organic content (TOC) and are measured using a detector specifically designed for this parameter. From a packed bed usage perspective it is easy to characterize the life time of the ion exchange bed based on the incoming concentration of the ions in the RO water and the total ion exchange capacity of the packed bed, however the same is not true for the organics as the mechanism of retention is notquantitative and the organic compound encountered in municipal water can vary depending on the source of the water.

[0005] Some have used ion exchange particles combined with carbon particles to remove inorganic and organic contaminants in the incoming water. But other than employing a carbon containing material either separately or in combination with mixed ion exchange materials, there has been no attempt to understand the root cause of the TOC or achieve the low levels of TOC in a scientific and systematic manner. Accordingly, there is a long-felt need in the art for improved water purification systems that can provide water having both low ionic content and low TOC.SUMMARY

[0006] It is one objective of the disclosed technology to purify the water and achieve the ionic purity specification that meets or exceeds Type 1 quality water. It is another objective to provide water of a low organic content so the water can be used for sensitive applications demanding both the high purity from an inorganic contaminant and organic contaminant perspective. Organic contaminant residual level and blanks are particularly important when pursuing HPLC, BOD or TOC analysis. In tissue culture and cell and gene therapy labs in particular, it is important to have water with a consistent TOC content as the impact of TOC on growth and harvesting is not well characterized.

[0007] The present disclosure first provides a method, comprising: contacting (i) an input water and (ii) an ion-exchange medium under conditions such that the ion-exchange medium exchanges anions and / or cations from the input water with hydroxide and / or hydronium ions respectively so as to give rise to a first water; contacting (i) the first water and a (ii) carbonaceous medium under conditions such that the carbonaceous medium removes at least one organic species from the first water so as to give rise to second water; and exchanging anions from the second water with hydroxide ions.

[0008] Also provided is a system, the system configured to perform a method of the present disclosure, for example a method according to any one of Aspects 1-8 or Aspects 10- 16.

[0009] Further provided is a method, comprising: reducing an ionic content of an input water by ion exchange so as to give rise to a first water; reducing a TOC content of the first water so as to give rise to a second water; and reducing an ionic content of the secondwater so to give rise to a third water. Without being bound to any particular theory or embodiment, the disclosed technology allows one to provide a product water that is comparatively low in both TOC and ionic contaminants; existing approaches produce water that is low in one of TOC and ionic contaminants but not low in both.

[0010] Additionally provided is a system, comprising: a flow path, the flow path comprising: a first ion removal stage, an organic content removal stage, the organic content removal stage located downstream from the first ion removal stage, and a second ion removal stage, the second ion removal stage located downstream from the first ion removal stage, and the second ion removal stage configured to exchange at least anions from a water contacted to the second ion removal stage with hydroxide ions. Removal of ions can include ion exchange with hydronium and / or hydroxide ions to convert the incoming stream to a purified stream. Thus, an ion removal stage can be considered an ion exchange stage - for example, a first ion removal stage can be considered a first ion exchange stage, and a second ion removal stage can be considered a second ion exchange stage.BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In the drawings, which are not necessarily drawn to scale, like numerals may describe similar components in different views. Like numerals having different letter suffixes may represent different instances of similar components. The drawings illustrate generally, by way of example, but not by way of limitation, various aspects discussed in the present document. In the drawings:

[0012] FIG. 1 depicts a standard water purification system.

[0013] FIG. 2 depicts an exemplary cartridge used in water purification systems.

[0014] FIG. 3 depicts an exemplary design configuration of a packed bed during water purification operation of the prior art.

[0015] FIG. 4 depicts an exemplary, non-limiting embodiment of the disclosed technology.

[0016] FIG. 5 depicts an exemplary, non-limiting embodiment of the disclosed technology.

[0017] FIG. 6 depicts an exemplary, non-limiting embodiment of the disclosed technology.

[0018] It should be understood that the included figures are illustrative only and that not all components - for example, detector cells, solenoid valves, and plumbing - are depicted in the figures.DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0019] The present disclosure may be understood more readily by reference to the following detailed description of desired embodiments and the examples included therein.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. In case of conflict, the present document, including definitions, will control. Preferred methods and materials are described below, although methods and materials similar or equivalent to those described herein can be used in practice or testing. All publications, patent applications, patents and other references mentioned herein are incorporated by reference in their entirety. The materials, methods, and examples disclosed herein are illustrative only and not intended to be limiting.

[0021] The singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise.

[0022] As used in the specification and in the claims, the term "comprising" can include the embodiments "consisting of' and "consisting essentially of.” The terms “comprise(s),” “include(s),” “having,” “has,” “can,” “contain(s),” and variants thereof, as used herein, are intended to be open-ended transitional phrases, terms, or words that require the presence of the named ingredients / steps and permit the presence of other ingredients / steps. However, such description should be construed as also describing compositions or processes as "consisting of' and "consisting essentially of' the enumerated ingredients / steps, which allows the presence of only the named ingredients / steps, along with any impurities that might result therefrom, and excludes other ingredients / steps.

[0023] As used herein, the terms “about” and “at or about” mean that the amount or value in question can be the value designated some other value approximately or about the same. It is generally understood, as used herein, that it is the nominal value indicated ±10% variation unless otherwise indicated or inferred. The term is intended to convey that similar values promote equivalent results or effects recited in the claims. That is, it is understood that amounts, sizes, formulations, parameters, and other quantities and characteristics are notand need not be exact, but can be approximate and / or larger or smaller, as desired, reflecting tolerances, conversion factors, rounding off, measurement error and the like, and other factors known to those of skill in the art. In general, an amount, size, formulation, parameter or other quantity or characteristic is “about” or “approximate” whether or not expressly stated to be such. It is understood that where “about” is used before a quantitative value, the parameter also includes the specific quantitative value itself, unless specifically stated otherwise.

[0024] Unless indicated to the contrary, the numerical values should be understood to include numerical values which are the same when reduced to the same number of significant figures and numerical values which differ from the stated value by less than the experimental error of conventional measurement technique of the type described in the present application to determine the value.

[0025] All ranges disclosed herein are inclusive of the recited endpoint and independently of the endpoints. The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value; they are sufficiently imprecise to include values approximating these ranges and / or values.

[0026] As used herein, approximating language can be applied to modify any quantitative representation that can vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term or terms, such as “about” and “substantially,” may not be limited to the precise value specified, in some cases. In at least some instances, the approximating language can correspond to the precision of an instrument for measuring the value. The modifier “about” should also be considered as disclosing the range defined by the absolute values of the two endpoints. For example, the expression “from about 2 to about 4” also discloses the range “from 2 to 4.” The term “about” can refer to plus or minus 10% of the indicated number. For example, “about 10%” can indicate a range of 9% to 11%, and “about 1” can mean from 0.9-1. 1. Other meanings of “about” can be apparent from the context, such as rounding off, so, for example “about 1” can also mean from 0.5 to 1 .4. Further, the term “comprising” should be understood as having its open- ended meaning of “including,” but the term also includes the closed meaning of the term “consisting.” For example, a composition that comprises components A and B can be a composition that includes A, B, and other components, but can also be a composition made of A and B only. Any documents cited herein are incorporated by reference in their entireties for any and all purposes.

[0027] Any embodiment or aspect provided herein is illustrative only and does not limit the scope of the present disclosure or the appended claims. Any part or parts of any one or more embodiments of aspects can be combined with any part or parts of any one or more other embodiments or aspects.

[0028] A cause of high TOC in existing packed bed devices was determined to be from leachates from the mixed bed ion exchange resins. Without being bound to any particular theory or embodiment, the anion exchange resin leaches out amines, aminated oligomers and ammonia due to the resin’s hydrolytic instability. The cation exchange resin leaches out sulfonated oligomers and sulfates, and there can be cross contamination of the resins due to the presence of large levels of leachate compromising the ion exchange function of the bed.

[0029] In existing devices utilizing a large mixed bed ion exchange resin, the purified water has a comparatively high level of TOC and is not suitable for sensitive applications such as water for HPLC, TOC and BOD analysis. Increasing adsorption of the leachate on to the oppositely charged bed also reduces the overall capacity of the ion exchange resin. Existing systems that use activated carbon bead packed beds are capable of removing the TOC, but also release anionic contaminants such as acid anions that are used for the activation aspect of the carbon particles, and the ionic purity of the bed is hence compromised.

[0030] As a compromise approach, some have adopted the concept of using a carbon bead packed column either in the beginning or have a mixed bed combined with a carbon bead packed column. These configurations, however, are ineffective in addressing the TOC levels. Since the leachates predominantly from the anion exchange materials are not removed.

[0031] FIG. 1 depicts a typical existing system; for simplicity purposes certain elements (such as solenoid valves and sensors) are not shown.

[0032] As shown, feed water is subjected to pretreatment; the pretreatment can be a prefilter to ensure the water does not deleteriously impact the reverse osmosis (RO) membrane operation. The pretreatment can be pursued in a separate module or integrated into the water purification apparatus.

[0033] Pretreated water is fed into the RO where the permeate which is substantially free from contamination is sent for further treatment using a UV lamp and then routed viapacked bed cartridges that contain both ion exchange materials and carbon beads. The function of the ion exchange materials is to remove ionic contaminants in the water, and carbon beads are employed typically to retain the TOC components. Purified water can then be routed via filters to remove particulate matter in the water and then routed to a storage tank. The water in the storage tank can be circulated further to purify the water and dispensed upon demand via the dispenser shown in FIG. 1

[0034] FIG. 2 depicts a typical cartridge used in water purification application. As shown, the design can include a cylinder-shaped structure which can be made from polymer material - such as PTFE, polypropylene, PVDF, or other polymers - and is filled with the particles having the desired functionality. The particles can be held in place by porous bed support materials; such materials can include porous polyethylene, polypropylene, or PTFE. End caps seal the tube and allow for the inlet and outlet connections. Flow distributors and other variations of the depicted design can also be used.

[0035] FIG. 3 provides an example packed bed during a water purification operation. A cartridge can include a single mixed bed ion exchange cartridge and an additional cartridge packed with porous carbon beads. The mixed bed can include anion exchange resin in fully regenerated hydroxide form and cation exchange resin in the fully regenerated hydronium form. Individual beds of anion or cation exchange resins that are frilly regenerated can also be used in this application; variations of this design not shown are packed sections in a single cartridge.

[0036] In the disclosed technology, a particular processing approach is provided to minimize the inherent levels of TOC. As one example, the first bed can be a mixed bed to maximize the ionic exchange. The resulting water from the packed bed can have comparatively high levels of TOC, for example on the order of > 10 ppb. The second bed can be selected to be a carbon bead packed column, and this placement acts to remove much of the TOC, although anionic contaminants can be present at a level high enough to compromise the purity of the water exiting from the bed. The disclosed technology then provides, in some embodiments, a further mixed bed section to capture any remaining anions eluting from the carbon bead packed columns. The bed length or bed capacity for the foregoing further mixed bed section can be, for example, not greater than 50% of the corresponding bed length or bed capacity of the first mixed bed, and the level of TOC in the output can be accordingly low.

[0037] In another embodiment, a third bed is placed downstream, which third bed can include anion exchange resins; the third bed can have the purpose of capturing the anionic contaminants from the carbon bead packed column. Because anion exchange resin is hydrolytically unstable, there can be a high level of amines and ammonia emanating from this bed, and therefore one can use a fourth bed that includes cation exchange resin so as to capture the cationic species. There can be a small level of leachate from the cation exchange resin, but this level can be reduced by a simple rinse of the packed bed. Thus, complete removal of leachates is achieved in the disclosed technology. The discrete beds of the disclosed technology can absorb the leachates in a more predictable manner, thus allowing for predictable ion exchange.

[0038] The water exiting from the cation exchange packed bed is free from ionic contaminants and has very low levels of TOC as per the present invention. It was observed that certain gases such as ammonia and carbon dioxide gas that are formed from the formation of carbonic acid that could compromise the ionic performance of the final water for a short duration upon startup of the system. To address this issue a short bed of mixed bed can be added as shown in FIG. 5 in the outlet section of the bed. While this section needs to be optimized to minimize the leachate levels the presence of this section behaves as a final insurance to insure good water purity from an ionic and organic content perspective.

[0039] Prior art water purifier devices use internal recirculation as a means of keeping the dead water zones to a minimal and to eliminate the presence of pathogens or bacteria within the system by exposing the water to the purification beds and UV treatment. The approach of the prior art per the present invention actually is detrimental since there is no means of removing the leachable and the prior art purification beds are not designed to minimize the leachates. In contrast the present invention can aid the recirculation minimizing the level of TOC contaminants in the water.

[0040] In summary, the disclosed technology invention provides - in some embodiments - systems and processes that capture leachates from anion exchangers in mixed bed packing or from anion exchange packing material and also minimize the level of TOC.

[0041] Examples

[0042] Example 1: A system of Figure 1 was configured with the water purification configuration of Figure 4. The conductivity of the water indicated that upon startup it took approximately 50 seconds to achieve a value of 18.2 MQ-cm for the resistivity indicatinghigh ionic purity of the water. The TOC was measured using a Sievers 500 RL e module from Veolia Water Technologies & Solutions, USA. The measured average value for TOC was 1.8 pg / L showing excellent results for both ionic purity and organic TOC levels. In another example, processed water was recirculated and showed little variation from the observed TOC levels, which is indicative of the favorable performance of the present invention.

[0043] Table 1 - exemplary TOC concentrations in output from exemplary, nonlimiting configuration.

[0044] Example 2: A system of Figure 1 was configured with the water purification configuration of Figure 5. The mixed bed section at the outlet of 513 designated as 514 was 10% of the bed length. The conductivity of the water indicated that upon startup it took approximately 40 seconds to achieve a value of 18.2 Mf2-cm for the resistivity indicating high ionic purity of the water. The 10 second decrease is attributable to a quick removal of any residual ions possibly originating from dissolved gases. Thus enabling faster generation of high purity water. The TOC was measured using a Sievers 500 RL e module from Veolia Water Technologies & Solutions, USA. The measured average value for TOC was 2.73 pg / L (n=5 runs) showing excellent results for both ionic purity and organic TOC levels. The TOC level was a little higher than the previous configuration from the added mixed bed section. Nevertheless, the level of TOC showed consistent purity and high performance.

[0045] Example 3: The water from the example 2 was tested using an Ion Chromatograph for trace level ions. The observed values were < 0.01 pg / L for sodium and < 0.02 pg / L for chloride ions indicating high purity of the water generated by the present invention.

[0046] Aspects

[0047] The following Aspects are illustrative only and do not limit the scope of the present disclosure or the appended claims. Any part or parts of any one or more Aspects can be combined with any part or parts of any one or more other Aspects.

[0048] Aspect 1. A method, comprising: contacting (i) an input water and (ii) an ion-exchange medium under conditions such that the ion-exchange medium exchanges anions and / or cations from the input water with hydroxide and / or hydronium ions respectively so as to give rise to a first water; contacting (i) the first water and a (ii) carbonaceous medium under conditions such that the carbonaceous medium removes at least one organic species from the first water so as to give rise to second water; and exchanging anions from the second water with hydroxide ions. The ion-exchange medium can include an anion exchange medium, a cation exchange medium, or even both an anion exchange medium and a cation exchange medium.

[0049] Aspect 2. The method of Aspect 1, wherein the exchanging anions from the second water is effected by an anion exchange medium in hydroxide form.

[0050] Aspect 3. The method of any one of Aspects 1-2, wherein exchanging anions from the second water gives rise to a third water, the method further comprising exchanging cations from the third water. This can be accomplished by, for example, contacting the third water and a cation exchange medium; this can also be accomplished by contacting the third water and a mixed-bed ion exchange medium that includes both a cation exchange medium and an anion exchange medium.

[0051] Aspect 4. The method of Aspect 3, wherein exchanging cations from the third water gives rise to a fourth water, the method further comprising exchanging anions and / or cations from the fourth water with hydroxide and / or hydronium ions respectively.

[0052] Aspect 5. The method of Aspect 1, wherein the exchanging anions from the second water is effected by a mixed-bed ion exchange medium.

[0053] Aspect 6. The method of Aspect 1, further comprising exchanging cations from the second water.

[0054] Aspect 7. The method of any one of Aspects 1-6, wherein the method gives rise to a product water having any one or more of (i) a TOC of less than 5 ppb, and (ii) a resistivity of greater than 18 Mfl-cm.

[0055] Aspect 8. The method of any one of Aspects 1-7, wherein the second water has a higher anionic content than that a corresponding anionic content of the first water.

[0056] Aspect 9. A system, the system configured to perform the method of any one of Aspects 1-8.

[0057] Aspect 10. A method, comprising: reducing an ionic content of an input water by ion exchange so as to give rise to a first water; reducing a TOC content of the first water so as to give rise to a second water; and reducing an ionic content of the second water so to give rise to a third water.

[0058] Aspect 11. The method of Aspect 10, wherein the reducing the ionic content of the second water comprises exchanging anions from the second water with hydroxide ions.

[0059] Aspect 12. The method of Aspect 11, wherein reducing the ionic content of the second water further comprises exchanging cations from the second water with hydronium ions.

[0060] Aspect 13. The method of any one of Aspects 10-12, further comprising reducing an ionic content of the third water.

[0061] Aspect 14. The method of Aspect 13, wherein reducing an ionic content of the third water comprises removing anions, cations, or both from the third water by exchanging for hydroxide and / or hydronium ions.

[0062] Aspect 15. The method of any one of Aspects 10-14, wherein reducing the ionic content of the input water is effected by a mixed-bed ion exchange medium.

[0063] Aspect 16. The method of any one of Aspects 10-15, wherein reducing the TOC content of the first water so as to give rise to the second water is effected by a carbonaceous medium.

[0064] Aspect 17. A system, the system configured to perform the method according to any one of Aspects 10-16.

[0065] Aspect 18. A system, comprising: a flow path, the flow path comprising:

[0066] - a first ion removal stage,

[0067] - an organic content removal stage,

[0068] the organic content removal stage located downstream from the first ion removal stage, and

[0069] - a second ion removal stage,

[0070] the second ion removal stage located downstream from the first ion removal stage, and

[0071] the second ion removal stage configured to exchange at least anions from a water contacted to the second ion removal stage with hydroxide ions.

[0072] The first ion removal stage (which can be characterized as an ion exchange stage) can include a cation exchange medium, an anion exchange medium, or both. The first ion exchange stage can be. for example, a mixed bed ion exchange medium.

[0073] Aspect 19. The system of Aspect 18, wherein the second ion removal stage further comprises a cation exchange medium. As described elsewhere herein, the second ion removal stage can be characterized as an ion exchange stage.

[0074] Aspect 20. The system of Aspect 18, further comprising a third ion removal stage, the third ion removal stage located downstream from the second ion removal stage, and the third ion removal stage configured to exchange at least cations from a water contacted to the third ion removal stage with hydronium ions.

[0075] Aspect 21. The system of Aspect 20, further comprising a fourth ion removal stage, the fourth ion removal stage located downstream from the third ion removal stage, and the fourth ion removal stage configured to exchange one or both of anions and cations from w ater communicated from the third ion removal stage to the fourth ion removal stage with exchangeable hydroxide and hydronium ions.

[0076] Aspect 22. The system of any one of Aspects 18-21, wherein the system is configured to output a product w ater having either or both of (i) a TOC of less than 5 ppb, and (ii) a resistivity of greater than 18 MQ-cm.

[0077] Figures

[0078] FIG. 4, FIG. 5, and FIG. 6 provide example, non-limiting depictions of the disclosed technology.

[0079] As shown in FIG. 4, system 400 can include ion exchange medium 402 (which can be a mixed bed that includes anion exchange resin and cation exchange resin), carbonaceous medium 405 (which can be a packed bed of carbon beads or other material configured to reduce TOC content), anion exchange medium 409 (which can be a bed of anionic exchange resin), and cation exchange medium 413 (which can be a bed of cationic exchange resin) are arranged in series with one another. The foregoing features can be arranged in the order shown in FIG. 4.

[0080] Input water 401 - which can be RO water - can be supplied to ion exchange medium 402, and ion exchange medium can output first water 403. Ion exchange medium 402 can be, for example, a mixed bed packing designed to remove ionic contaminants in the input water. Ion exchange medium 402 can be, for example, anion exchange and cation exchange packings in separate cartridges or in sections to remove ionic contaminants in the input water.

[0081] First water 403 can be communicated to carbonaceous medium 405. and carbonaceous medium 405 can output second water 407.

[0082] Carbonaceous medium 405 can remove at least one organic species from first water 403 so as to reduce the TOC of second water 403; carbonaceous medium 405 can be a carbon bead bed that is designed to trap organics. Second water 407 can, in some embodiments, have an anionic content that is higher than an anionic content of input water 401.

[0083] Second water 407 can be communicated to anion exchange medium 409, and anion exchange medium 409 can exchange anions from second water 407 and output third water 411. Anion exchange medium 409 can be an anion exchange resin packed bed that is designed to remove anionic contaminants.

[0084] Exchanging anions from the second water can by effected by an anion exchange medium in hydroxide form; the anion exchange medium can be present in a bed that includes cation exchange medium or does not include cation exchange medium.

[0085] Third water 411 can be communicated to ion exchange medium 413. Ion exchange medium 413 can exchange cations from third water 411 and then output fourth water 415. Ion exchange medium 413 can be a cation exchange resin packed bed that is designed to remove cationic contaminants. Ion exchange medium 413 can also include anion exchange medium, but this is not a requirement, as ion exchange medium 413 can be free of anion exchange medium.

[0086] Fourth water 415 can be a purified water with low TOC; fourth water 415 can be further treated - for example, by filtering or UV treatment - and then be delivered to a use location, to a storage location with or without UV treatment, or any of the foregoing. Fourth water 415 can have either or both of (i) a TOC of less than 5 ppb. and (ii) a resistivity of greater than 18 MQ-cm. Thus, without being bound to any particular theory or embodiment, the disclosed technology can reduce the ion content of an input water, reducethe TOC content of the water, and further compensate for additional ions that may leach into the water in connection with the TOC reduction.

[0087] As shown in FIG. 5, system 500 can include ion exchange medium 502 (which can include anion exchange resin and cation exchange resin), carbonaceous medium 505 (which can be a packed bed of carbon beads or other material configured to reduce TOC content), anion exchange medium 509 (which can be a bed of anionic exchange resin), cation exchange medium 513 (which can be a bed of cationic exchange resin, which bed can further include an amount of anionic exchange resin), and ion exchange medium 514 (which can include an anion exchange resin with or without cation exchange resin) are arranged in series with one another. It should be understood that ion exchange medium 513 and ion exchange medium 514 can both be present in a single mixed packed bed stage. Ion exchange medium 514 can have a bed length or bed capacity that is less than 50%, less than 40%. less than 30%, less than 20%, or even less than 10% of the bed length or bed capacity of ion exchange medium 502 and / or ion exchange medium 513. As an example, if ion exchange medium 502 has a bed capacity of Im3, ion exchange medium 514 can have a bed capacity that is less than 50% of that capacity, for example. 0.2 m3. As another example, if ion exchange medium 513 has a bed capacity of 1 m3, ion exchange medium 514 can have a bed capacity that is less than 50% of that capacity, for example 0.3 m3.

[0088] Input water 501 can be supplied to ion exchange medium 502, and ion exchange medium can output first water 503. First water 503 can be communicated to carbonaceous medium 505, and carbonaceous medium 505 can output second water 507.

[0089] Carbonaceous medium 505 can remove at least one organic species from first water 503 so as to reduce the TOC of second water 503. Second water 507 can, in some embodiments, have an anionic content that is higher than an anionic content of input water 501.

[0090] Second water 507 can be communicated to anion exchange medium 509, and anion exchange medium 509 can exchange anions from second water 507 and output third water 511. Exchanging anions from the second water can by effected by an anion exchange medium in hydroxide form; the anion exchange medium can be present in a bed that does or does not include cation exchange medium.

[0091] Third water 511 can be communicated to ion exchange medium 513. Ion exchange medium 513 can exchange cations from third water 511. Ion exchange mediumand then output fourth water 515. Fourth water 515 can then be further treated - for example, by filtering or UV treatment - and can then be delivered to a use location, to a storage location, or any of the foregoing.

[0092] FIG. 6 provides a further example depiction of the disclosed technology. As shown, input water 601 is communicated to ion exchange medium 602 (which can be a mixed bed that includes both anion exchange resin and cation exchange resin). First water 602 is output from ion exchange medium 602 and then communicated to carbonaceous medium 605, which can be a carbon bead packed column. The output of carbonaceous medium 605 is communicated to ion exchange medium 607, which can include any one or more of an anion exchange medium, a cation exchange medium, or both. Ion exchange medium 607 can have a bed length or bed capacity that is less than 50%, less than 40%, less than 30%, less than 20%. or even less than 10% of the bed length or bed capacity of ion exchange medium 602. As an example, if ion exchange medium 602 has a bed capacity of Im3, ion exchange medium 607 can have a bed capacity that is less than 50% of that capacity, for example, 0.2 m3. As another example, if ion exchange medium 605 has a bed capacity of 1 m3, ion exchange medium 607 can have a bed capacity that is less than 50% of that capacity, for example 0.3 m3.

Claims

What is Claimed:

1. A method, comprising: contacting (i) an input water and (ii) an ion-exchange medium under conditions such that the ion-exchange medium exchanges anions and / or cations from the input water with hydroxide and / or hydronium ions respectively so as to give rise to a first water; contacting (i) the first water and a (ii) carbonaceous medium under conditions such that the carbonaceous medium removes at least one organic species from the first water so as to give rise to second water; and exchanging anions from the second water with hydroxide ions.

2. The method of claim 1, wherein the exchanging anions from the second water is effected by an anion exchange medium in hydroxide form3. The method of any one of claims 1-2, wherein exchanging anions from the second water gives rise to a third water, the method further comprising exchanging cations from the third water.

4. The method of claim 3, wherein exchanging cations from the third water gives rise to a fourth water, the method further comprising exchanging anions and cations from the fourth water with hydroxide and hydronium ions respectively5. The method of claim 1, wherein the exchanging anions from the second water is effected by a mixed-bed ion exchange medium6. The method of claim 1, further comprising exchanging cations from the second water.

7. The method of any one of claims 1-2, wherein the method gives rise to a product water having any one or more of (i) a TOC of less than 5 ppb, and (ii) a resistivity of greater than 18 MQ-cm.

8. The method of any one of claims 1-2, wherein the second water has a higher anionic content than that a corresponding anionic content of the first water.

9. A system, the system configured to perform the method of any one of claims 1-2.

10. A method, comprising: reducing an ionic content of an input water by ion exchange so as to give rise to a first water; reducing a TOC content of the first water so as to give rise to a second water; and reducing an ionic content of the second water so to give rise to a third water.1 1. The method of claim 10, wherein the reducing the ionic content of the second water comprises exchanging anions from the second water with hydroxide ions.

12. The method of claim 11. wherein reducing the ionic content of the second water further comprises exchanging cations from the second water with hydronium ions.

13. The method of any one of claims 10-12, further comprising reducing an ionic content of the third water.

14. The method of claim 13, wherein reducing an ionic content of the third water comprises removing anions, cations, or both from the third water by exchanging for hydroxide and / or hydronium ions.

15. The method of any one of claims 10-12, wherein reducing the ionic content of the input water is effected by a mixed-bed ion exchange medium.

16. The method of any one of claims 10-12, wherein reducing the TOC content of the first water so as to give rise to the second water is effected by a carbonaceous medium.

17. A system, the system configured to perform the method according to any one of claims 10-12.

18. A system, comprising: a flow path, the flow path comprising:- a first ion removal stage,- an organic content removal stage, the organic content removal stage located downstream from the first ion removal stage, and- a second ion removal stage, the second ion removal stage located downstream from the first ion removal stage, and the second ion removal stage configured to exchange at least anions from a water contacted to the second ion removal stage with hydroxide ions.

19. The system of claim 18, wherein the second ion removal stage further comprises a cation exchange medium.

20. The system of claim 18, further comprising a third ion removal stage, the third ion removal stage located downstream from the second ion removal stage, and the third ion removal stage configured to exchange at least cations from a water contacted to the third ion removal stage with hydronium ions21. The system of claim 20, further comprising a fourth ion removal stage, the fourth ion removal stage located downstream from the third ion removal stage, and the fourth ion removal stage configured to exchange one or both of anions and cations from water communicated from the third ion removal stage to the fourth ion removal stage with exchangeable hydroxide and hydronium ions.

22. The system of any one of claims 18-21, wherein the system is configured to output a product water having either or both of (i) a TOC of less than 5 ppb, and (ii) a resistivity of greater than 18 MQ-cm.

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