HK1073271B - Method and apparatus for fluid treatment by reverse osmosis under acidic conditions - Google Patents

Description

Method and apparatus for treating fluids under acidic conditions by reverse osmosis

Technical Field

The present invention relates to a method for treating acidic water and wastewater in membranes based on water treatment, purification, and concentration systems, and to an apparatus for carrying out the method. More particularly, the present invention relates to a feed water pretreatment method and a method of operating a membrane based treatment system such as reverse osmosis ("RO") and microfiltration ("NF") that can achieve higher solute rejection, thereby producing very high purity water (containing less solute) while significantly increasing the operational effectiveness of the water treatment facility.

Background

Naturally occurring acidic waters and acidic waste waters produced in industrial processes are present in many parts of the world. Conventional methods commonly used to treat such water include neutralization with a base to raise its pH so that the water can be released or beneficially applied. However, these methods are not always desirable or even feasible in some cases. Also, the cost of the required chemicals, particularly the alkali, can be very high.

If the treated water is to be drunk, it does not generally meet the world health organization standards that it must meet, which are standards of no more than 500 milligrams of soluble solids per liter of drinking water and no more than 250mg/L of either sulfate or chloride ions. But the criteria for reuse of water are much stricter than this in most industrial applications. Thus, the "direct neutralization" treatment method is generally unacceptable in most water treatment applications.

In industrial applications, acidic water treatment/recovery is typically based on ion exchange processes or on Reverse Osmosis (RO) systems. Depending on factors such as hardness (multivalent ions), Total Organic Carbon (TOC), and other contaminants present in the water, anion exchange processes may be used to treat such acidic feedwater to reduce/eliminate acidity. In addition, the addition of a cation exchange step before or after the anion exchange step does result in a completely demineralized water. For this purpose, weakly basic, moderately basic or strongly basic anion exchange resins can be used alone or in combination.

The main advantages of these existing ion exchange treatment methods are:

(1) in industry, these processes are considered "passive", i.e. the process does not easily change the properties of the feed.

(2) Compared with the conventional reverse osmosis method, the method has lower cost.

The main disadvantages of these existing ion exchange treatment processes are:

(1) the quality, type (e.g., sodium type) and amount of base required (to regenerate resin IX) is actually higher and/or more stringent than in the direct neutralization process, and the cost of the required chemicals is very high.

(2) Large volumes of anion exchange resin are required; these resins are generally very expensive. Thus, the cost of initiation and regeneration of ion exchange resins in such systems is very high compared to membrane-based treatment systems.

(3) Depending on the specific variation of the ion exchange resin used, the contamination due to Total Organic Carbon (TOC) can be very high. Unfortunately, the contaminated anionic resin is difficult to clean and costly. And cannot be removed of non-ionic TOC components such as IPA (isopropyl alcohol). In addition, the TOC component which is substantially cationic cannot be removed. Removal of TOC or at least significant reduction of TOC is a very important requirement, often in many industrial applications where it is desirable to reuse the treated water.

In conventional membranes based on systems used to treat acidic wastewater or natural acidic water, the PH of the RO/NF feed is typically adjusted by the addition of a base. Thus, these conventional RO/NF systems operate at or substantially near neutral pH. Conventional RO/NF systems, except for some special cases, are capable of ensuring that RO/NF membranes are not operated in a PH environment that is damaged by an excessively high or excessively low PH environment. More importantly, for many cases where membrane materials are commonly used, the total solute rejection across the membrane is typically highest at a pH of about 8. Therefore, it is a common theory in the water treatment industry to avoid the use of RO/NF at low pH conditions.

However, the characteristics of some basic RO/NF processes have many potential advantages over ion exchange processes, such as:

(1) RO/NF can remove both cations and anions.

(2) Typically, RO/NF removes a significant percentage of the TOC present before media or membrane fouling becomes a major problem. For example, RO processes can remove about 80% or more of non-ionic species, such as IPA.

(3) Unlike non-ion exchange processes, the fixed cost as well as the operating cost of RO/NF processes are not very sensitive to the chemistry of the influent water.

To my knowledge, conventional RO/NF systems for treating such acidic waters, whether for wastewater or for naturally occurring waters, still suffer from significant disadvantages. These deficiencies include:

(1) the quality and cost of the alkali required to neutralize the RO feed is comparable to neutralization alone. The overall processing cost is therefore high, since the fixed and running costs of the RO process must be added to the neutralization costs.

(2) The combination of the RO process after pH neutralization is very inefficient because the total solid solution is first increased by the pH neutralization step, but the total solid solution is then decreased by the RO/NF step.

(3) RO/NF systems are very sensitive to biological and/or particulate and/or organic contamination when operated in a neutral or near neutral pH environment. Unfortunately, the thin film composite membranes commonly used are not resistant to oxidizing biocides such as chlorine. Controlling biological contamination is therefore problematic, particularly in the case of treating water containing organic contaminants.

There remains a need for a simple, efficient, and cost-effective method of treating acidic water, which may be natural water or wastewater produced from other processes. It is also desirable to provide water of the desired purity while requiring minimal maintenance. In particular, in many industrial fields such as semiconductors, chemical products, mining industry, pharmaceutical industry, biotechnology, and power plants, it is required to improve the water supply efficiency and the fixed cost and the operating cost of the water treatment system.

It is clear that it would be extremely advantageous if new water treatment processes could be developed that combine the advantages of conventional RO/NF membrane treatment processes and ion exchange processes, particularly for naturally occurring acidic waters as well as industrially generated waste waters. In addition, such a process would be very attractive if it could avoid the objectionable disadvantages of reverse osmosis/microfiltration or ion exchange. In summary, an economical, important new acidic water treatment process should have some, if not most, of the advantages of both reverse osmosis/microfiltration and ion exchange processes. Any such new process must also be effective in overcoming the difficulties that plague reverse osmosis/microfiltration or ion exchange processes.

Objects, advantages and novel features

From the foregoing, it is an important and primary object of the present invention to provide a novel method of treating water so as to continuously and reliably produce purified water continuously from acidic water or wastewater. More particularly, an important object of the present invention is to provide a membrane for a water treatment method which can avoid conventional pretreatment costs and contamination problems during treatment, thereby surely providing a method for preparing purified water with high efficiency. Another object of the present invention is to provide the water treatment method as described above, wherein:

(1) the advantage of the process of the present invention is that it provides a more economical and easy process than conventional reverse osmosis membrane/microfiltration or ion exchange processes in terms of all "capital and operating costs".

(2) The process of the present invention is intended to be free of "tight controls" so that the process is readily capable of treating a wide variety of feed waters.

(3) The advantage of the process of the invention is that it enables the preparation of products of consistently high quality.

(4) The method of the present invention is directed to reverse osmosis/microfiltration membranes configured to be less susceptible to biological or organic contamination.

(5) The process of the present invention is aimed at the simultaneous removal of cationic, anionic and nonionic contaminants.

(6) The method of the invention aims at virtually complete removal or elimination of the TOC present, independently of the ionic character of the TOC component.

(7) The method of the present invention aims at minimizing the addition of chemicals, thereby not only reducing costs but also being environmentally friendly.

(8) An advantage of the process of the present invention is that it can be achieved using readily available ingredients that are routinely prepared by a number of companies.

(9) The method for treating acidic water or wastewater according to the present invention is characterized in that the purchasable components are cooperative as a whole, rather than conflicting, so that the advantages of the equipment used for carrying out the method can be fully utilized.

(10) The present invention has the advantage of achieving high recovery, or volumetric efficiency, when treating acidic water or wastewater.

(11) Another advantage of the membrane is that it can achieve higher yields (flow rates) than conventional systems, and can minimize or eliminate membrane fouling; more importantly, this reduces the capital and operating costs.

(12) Simplification of the pretreatment operation and cost reduction of the reverse osmosis/microfiltration method are also objects of the present invention, and this can be easily achieved by the acidic water treatment method of the present invention.

Other important objects, features, and additional advantages of the present invention will become apparent to those skilled in the art from the foregoing, the following detailed description, and the appended claims and drawings.

Drawings

To ensure a more complete understanding of the present invention, its features and advantages, reference is now made to the following detailed description of the invention, taken in conjunction with the accompanying drawings, in which:

FIG. 1 shows a flow diagram of an apparatus used in the field test of the method for treating acidic water and wastewater of the present invention;

FIG. 2 shows a general process flow diagram of the water treatment process of the present invention for treating different feed waters in different fields.

The foregoing illustrative data includes various method steps and processing elements that may be present or omitted from actual operation depending on the circumstances. The drawings are intended to depict at least those elements that may be used to facilitate an understanding of various embodiments and aspects of the invention. Other different process steps and treatment elements that can emulate a low pH membrane treatment process can be used, particularly for the various different functional elements shown, to provide a complete water or wastewater treatment system suitable for use in an environmental system.

Detailed Description

Through extensive research and evaluation of the deficiencies in the existing methods, a new water treatment method for treating acidic water is now being developed. Importantly i have determined that certain reverse osmosis/microfiltration systems can be operated successfully at pH as low as 2 without any or minimal chemical or physical pretreatment. The current lowest pH limit is determined by the nature of commercially available continuously operable reverse osmosis membranes, which are at about pH 2.0. In the future, if better membranes (i.e., lower pH tolerance) are available, the process of the invention can be operated at lower pH than the current limit of pH 2.0.

Despite operating at low pH, complete exclusion of cationic solutes and a variety of anionic solutes can be achieved relative to conventional industry manuals. The ability to exclude sodium and ammonium ions is also very high, which is a very significant and unexpected advantage of the novel acidic water treatment process of the present invention. The capacity for TOC removal is also very high under the operating conditions of the novel acidic water treatment process of the present invention.

I have also found that an additional step of TOC removal before (or after, or even after the anion exchange step) of feeding water to a low pH reverse osmosis membrane can produce the desired low TOC content in the final product water. Acceptable methods for TOC removal include:

(1) bubbling in a reservoir of water or any other suitable container, including microbubbles using air or an inert gas;

(2) mechanical or membrane processes to degas;

(3) irradiating with ultraviolet light of 185nm wavelength, with or without the addition of an oxidizing agent, such as hydrogen peroxide and/or ozone;

(4) if desired, divalent or trivalent iron ions may be added along with the hydrogen peroxide to form a Fenton's reagent known to be effective in removing oxides of the TOC compound;

(5) ozone is added to the feed water or product water.

Ferric or ferrous salts have particularly important applications when the hydrogen peroxide present in the wastewater of semiconductor manufacturing processes is increased. In this case, the oxidation products are typically organic acids, and or carbon dioxide, which can be effectively removed by an anion exchange step. But IPA that has not been previously oxidized cannot be removed by the anion exchange step because it cannot be ionized.

FIG. 1 shows a test set-up for evaluating the process according to the invention for treating acidic waste water. A three-stage reverse osmosis system is used. Feed water having an electrical conductance of 2700uS/cm at a pressure of 1.45MPa and a flow rate of 2m³At a pH of 2.6 and a temperature of 28 ℃ in the first stage of the system. The first stage effluent was then sent to the second stage at 1.4 MPa. The output of the second stage is fed to the third stage at 1.35 MPa. Finally, the discharged concentrate of the third stage is at 0.5m at a pressure of 1.25MPa and a pH of 2.4³Flow rate was released/hr. The permeate flow rate in the three stages was 1.5m³Hr, pressure 0.3MPa and conductance 28.5 uS/cm.

In summary, considering all three manufacturing stages, the average flow rate of product produced is 22.1 gallons per square foot per day (0.99089 m)³/m²/day). The overall recovery was about 75%. The RO permeate was then sent to an anion exchanger at a pressure of 0.02MPa to produce a final effluent after ion exchange with a conductance of 6.7 uS/cm.

The schematic results of such tests, in particular the high purity of the RO product, and the final effluent from the anion exchange step, demonstrate the effectiveness of the process of the present invention.

FIG. 2 is a general flow chart showing the industrial application of the acidic wastewater treatment method of the present invention. The raw acidic water 10 may be provided directly to the low pH RO unit 12 as shown or alternatively, may be passed sequentially through one or more pretreatment system units as shown in phantom. First, raw water 10 may be fed to a UV unit 20, wherein hydrogen peroxide 22 and/or a source 24 of ferrous or ferric ions is preferably provided. The partially treated water then enters a degassing unit 30 or other liquid-gas contactor to further remove TOC components. The effluent from the RO is further processed or released if standards are met. The permeate, shown by line 32, is sent to an anion exchange ("1-X") unit 34. The ion exchange treated product is then suitable for use as a supplement to the ultrapure water system 40 or may optionally be fed to the primary mixed bed 1-X unit 42 and/or the secondary mixed bed 1-X unit 44. The high purity water may then be used or further suitably treated in a filtration unit 50 or a second UV treatment apparatus 52 before being fed into an Ultra Pure Water (UPW) system 54.

The processes described herein can be carried out in a separation unit comprising at least one membrane separator to produce a less soluble product stream and a more soluble waste stream. The process can provide a feed water stream containing solutes for treatment. In some cases, these solutes can include at least one component that contributes to membrane fouling when the feedwater is free of free mineral acids. The pH of the feed water is adjusted, if necessary, to ensure that at least some free mineral acid is present in the feed water to the membrane separator prior to treatment of the feed water in the membrane separator. The pH adjusted feed water is fed through a membrane separation device in which the membrane substantially blocks the passage of at least some of the solutes to concentrate the feed water to a predetermined concentration, producing (i) a reject stream containing more solutes and (ii) a product stream containing less solutes. The pH of the feed water is typically adjusted to about 4.3 or less in the process. Importantly, the process can be applied where the membrane separator is a reverse osmosis membrane or a microfiltration membrane or a loose reverse osmosis membrane.

For many important applications, the feedwater includes a Total Organic Carbon (TOC) component, and the Total Organic Carbon (TOC) can be effectively removed from the product stream. For many applications, the treatment objective includes removing the TOC such that the TOC present in the product stream is about 10% or less of the concentration of the component in the feedwater. The process can be effectively used when the TOC composition includes one or more species that are primarily non-ionic (e.g., isopropanol and acetone).

Removal of other components is also important. For example, where the feedwater includes sodium ions, the treatment in some applications may be to the extent that the concentration of sodium ions in the product stream is about 2% or less of the concentration of sodium ions in the feedwater. When the feedwater contains ammonium ions, the treatment in some applications may be to the extent that the concentration of ammonium ions in the product stream is about 8% or less of the concentration of ammonium ions in the feedwater. Where the feed water contains chloride ions, the treatment in some applications may be to the extent that the concentration of chloride ions in the product stream is about 25% or less of the concentration of chloride ions in the feed water. When sulfate ions are present in the feed water, the treatment can be to the extent that the sulfate ion concentration in the product stream is about 0.5% or less of the sulfate ion concentration in the feed water. But contains chloride ions, the product stream has a concentration of fluoride ions substantially the same as the concentration of fluoride ions present in the feedwater stream.

For the additional step of the process of treating the feed water in a membrane separation system under pH conditions, the free mineral acid present in the product stream can be removed, if not completely, at least to the extent desired in the anion exchange system. Suitable anion exchange systems may be (a) weakly basic anion exchange systems, (b) moderately basic anion exchange systems, or (c) strongly basic anion exchange systems. If desired, the product stream can be treated using an anion exchange system to effectively remove all anions contained therein.

In order to enhance the treatment effect, in particular the removal of TOC components, an additional feed water treatment step may be added before the treatment in the membrane separation unit. Such treatment steps include, under appropriate conditions, the addition of ferric or ferrous ions to the feed water. In addition, hydrogen peroxide may be added in such processes, for example, to generate Fenton's reagent for TOC treatment. In this case, the total organic carbon component can be effectively removed from the product stream. Additionally or alternatively, the feedwater stream may be further treated by an added UV light source illuminating the feedwater stream prior to membrane separation, and in this manner, the total organic carbon components may be effectively removed from the product stream. For further processing to obtain a highly purified water effluent from all processing steps, a step of irradiating the product water stream with a UV light source is added, whereby the total organic carbon content can be effectively removed from the product stream.

In additional embodiments, the method further comprises ozonating the feedwater stream with an ozone-containing gas, wherein the total organic carbon components can be effectively removed from the product stream. Alternatively or additionally, the method further comprises the step of ozonating the product water stream with an ozone-containing gas, whereby total organic carbon components can be effectively removed from the product stream.

In additional embodiments of the method of treating feedwater in a low pH membrane separation operation of the present invention, in other instances where the feedwater contains hydrogen peroxide, either from an industrial process or through a pretreatment step, a process may be used that further includes a step of treating the feedwater stream in an activated carbon system, whereby hydrogen peroxide may be effectively removed from the product stream.

Permeate water product is typically readily available at a flow rate of at least 15 gallons per square foot per day. More importantly, the recovery is generally at least sufficient to provide a ratio of the amount of the resulting product stream to the amount of the feedwater stream provided of about 75% or greater. In other embodiments, the recovery is sufficient to provide a ratio of the amount of the resulting product stream to the amount of the feedwater stream provided of about 80% or greater. In other embodiments, the recovery is sufficient such that the ratio of the amount of the resulting product stream to the amount of the feedwater stream provided is about 85% or greater. In still other embodiments, the recovery is sufficient such that the ratio of the amount of the resulting product stream to the amount of the feedwater stream provided is about 90% or greater. In some applications, it is desirable that the recovery be sufficient to provide a ratio of the amount of the resulting product stream to the amount of the feedwater stream provided of about 95% or greater.

For other more treatment processes incorporating the alkaline low pH membrane separation process described herein, additional pretreatment steps may be performed prior to acidifying the feedwater. Such pretreatment steps include (a) media filtration, (b) cartridge filtration, (c) ultrafiltration, (d) nanofiltration, (e) oxidant removal, (f) softening, (g) cation exchange, (h) degassing, or (i) oxygen removal. In some embodiments, the cation exchange pretreatment step may be accomplished by weak acid cation exchange. In another embodiment, the cation exchange pretreatment step can be accomplished by strong acid cation exchange. Additionally, the oxidant removal pretreatment step comprises adding sodium metabisulfite to said feed water. More specifically, the processes provided herein can be generally described as treating a feedwater stream in a membrane separation apparatus having at least one unit with a membrane separator to produce a less dissolved product stream and a more dissolved waste stream. The process provides a feedwater stream containing solutes, and the pH of the feedwater stream is adjusted to obtain a pretreated feedwater stream, if necessary to ensure the presence of at least some mineral acid therein. A flow of pretreated feedwater having a predetermined pH is passed through a membrane separation device wherein the membrane substantially blocks the passage of at least some of the substances, thereby concentrating the pretreated feedwater to a predetermined concentration. A waste stream containing more solutes is produced having a lower pH than the pretreated feedwater stream. A lower solute containing product stream having a higher pH than the pretreated feedwater stream may also be produced.

The disclosed method may be advantageously employed by using a step of regenerating the effluent stream from the cation exchange system. For example, such methods may include the step of using an effluent stream as the acid source for regenerating a weak acid cation exchange system. Alternatively, such methods can include the step of using an effluent stream as an acid source for regenerating the strong acid cation exchange system.

The use of membrane separation equipment, particularly in combination with reverse osmosis/microfiltration and ion exchange equipment, for treating acidic waters provides a revolutionary and unexpected result by the process described herein, i.e., simultaneous reduction of all dissolved solids in the water to be treated, and reliable high purity in the purified RO permeate. This method of using a membrane separation system, particularly a reverse osmosis system, has significant advantages in treating sour water while reducing capital costs and operating costs of the water treatment system. In addition, for a given efficiency, whether in neutralization or ion exchange regeneration or RO cleaning, the amount of chemicals used per gallon of product water produced is greatly reduced.

It will be seen from the foregoing that, given the description of the method, the objects of the invention are efficiently attained and, since certain changes may be made in carrying out the method and in the construction of a suitable apparatus for carrying out the method and producing the desired product as set forth above, it will be understood that the invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. For example, while I have presented an exemplary design for treating sour water, other embodiments may achieve the results of the inventive method disclosed herein. Thus, it will be appreciated that the foregoing description of representative embodiments of the invention not only represents an object of the invention, but also facilitates a better understanding of the invention, and is not intended to limit the invention or the invention in the manner disclosed. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims. Thus, the claims are intended to cover the methods and structures described herein, including not only the structures described or the equivalents of those structures, but also equivalent structures or methods. Accordingly, it is intended that the scope of the invention as defined in the claims be construed to include the embodiments presented with the full breadth of the description or equivalents thereof.

Claims (51)

1. A method of treating a feedwater stream in a membrane separation device to produce a product stream containing less dissolved species and a reject stream containing more dissolved species, said membrane separation device including at least one reverse osmosis or nanofiltration membrane, said method comprising:

(a) providing a feedwater stream having solutes therein;

(b) adjusting the pH of said feedwater, if necessary, to a pH of 4.3 or less to ensure at least some free inorganic acidity is present in said feedwater to provide a pretreated feedwater stream;

(c) passing said pretreated feedwater stream through said membrane separation device, said membrane separation device substantially preventing passage of at least some dissolved species, to concentrate said feedwater to a preselected concentration factor to produce

(i) A waste stream containing more solutes and having a pH lower than said pretreated feedwater stream, and

(ii) a less soluble product stream having a pH greater than the pretreated feedwater stream.

2. The method of claim 1, wherein the feed water has a pH of or is adjusted to 2.6 or less.

3. The process of claim 1 wherein said membrane separator is comprised of a reverse osmosis membrane.

4. The process of claim 1 wherein the membrane separator consists of a nanofiltration membrane.

5. The process of claim 1 wherein said membrane separator is comprised of a loose reverse osmosis membrane.

6. The process of claim 1, 3, 4 or 5 wherein said feed water contains a Total Organic Carbon (TOC) component, wherein said Total Organic Carbon (TOC) is effectively removed from said product stream.

7. The process of claim 6 wherein said Total Organic Carbon (TOC) component in said product stream is 10% or less of the concentration of said component in said feedwater.

8. The method of claim 6, wherein said TOC comprises one or more non-ionized species, and wherein said one or more non-ionized species is selected from the group consisting of (a) isopropanol, and (b) acetone.

9. The method of claim 7, wherein said TOC comprises one or more non-ionized species, wherein said one or more non-ionized species is selected from the group consisting of (a) isopropanol, and (b) acetone.

10. The method of claim 1 or 3, wherein said feed water contains sodium ions, and wherein said product stream contains sodium ions at a concentration of 2% or less of the sodium ions contained in said feed water.

11. The process of claim 1 or 3 wherein said feed water contains ammonium ions and wherein said product stream contains ammonium ions at a concentration of 8% or less of the ammonium ions contained in said feed water.

12. The process of claim 1 or 3 wherein said feedwater contains chloride ions, and wherein said product stream contains chloride ions at a concentration of 25% or less of the chloride ions contained in said feedwater.

13. A process according to claim 1 or 3 wherein said feed water contains sulfate ions and wherein said product stream contains sulfate ions at a concentration of 0.5% or less of the sulfate ions contained in said feed water.

14. The process of claim 3 or 4 wherein said feedwater comprises fluoride ions, and the concentration of fluoride ions in said product stream is the same as the concentration of fluoride ions in said feedwater stream.

15. The process of claim 1, 4 or 5 wherein said product stream contains free inorganic acidity, and wherein said process further comprises treating said product stream in an anion exchange system effective to remove free inorganic acidity from said product stream.

16. The method of claim 15, wherein the anion exchange system is selected from one or more of the following: (a) a weak base anion exchange system, (b) a medium base anion exchange system, and (c) a strong base anion exchange system.

17. The process of claim 15 wherein said anion exchange system is effective to remove all anions contained in said product stream.

18. The method of claim 1 further comprising adding ferric or ferrous ions to the feed water as a reactant to facilitate removal of TOC prior to the feed water entering the reverse osmosis or nanofiltration membrane.

19. The method of claim 18, further comprising adding hydrogen peroxide to the feed water.

20. The process as set forth in claim 18 or 19 wherein said feedwater comprises a total organic carbon component, and wherein said total organic carbon component is effectively removed from said product stream.

21. The process of claim 1 wherein said feedwater comprises a total organic carbon component, wherein said process further comprises the step of irradiating said feedwater stream with a UV light source, and wherein said total organic carbon component is effectively removed from said product stream.

22. The process of claim 1 wherein said feedwater comprises a total organic carbon component, wherein said process further comprises the step of irradiating said product stream with a UV light source, wherein said total organic carbon component is effectively removed from said product stream.

23. The process as set forth in claim 1, wherein said feedwater comprises a total organic carbon component, said process further comprising ozonating said feedwater stream with an ozone-containing gas, wherein said total organic carbon component is effectively removed from said product stream.

24. The process of claim 1 wherein said feedwater comprises a total organic carbon component and said process further comprises ozonating said product stream with an ozone-containing gas, wherein said total organic carbon component is effectively removed from said product stream.

25. The process of claim 1 wherein said feedwater comprises hydrogen peroxide, and wherein said process further comprises treating said feedwater stream in an activated carbon system, and wherein said hydrogen peroxide is effectively removed from said product stream.

26. The method of claim 1 wherein said reverse osmosis membrane produces said product stream at a yield of at least 15 gallons per square foot per day.

27. The process of claim 1 wherein the ratio of the amount of said produced product stream to the amount of said provided feedwater stream is 75% or greater.

28. The process of claim 1 wherein the ratio of the amount of said produced product stream to the amount of said provided feedwater stream is 80% or greater.

29. The process of claim 1 wherein the ratio of the amount of said produced product stream to the amount of said provided feedwater stream is 85% or greater.

30. The process of claim 1 wherein the ratio of the amount of said produced product stream to the amount of said provided feedwater stream is 90% or greater.

31. The process of claim 1 wherein the ratio of the amount of said produced product stream to the amount of said provided feedwater stream is 95% or greater.

32. The process of claim 1, further comprising one or more additional pretreatment processes prior to adjusting the pH of said feed water, if necessary, to a pH of 4.3 or less, wherein said pretreatment processes are selected from the group consisting of (a) media filtration, (b) cartridge filtration, (c) ultrafiltration, (d) nanofiltration, (e) oxidant removal, (f) softening, (g) cation exchange systems, (h) degassing, and (i) oxygen removal.

33. A process as set forth in claim 32, wherein said pretreatment of said cation exchange system comprises weak acid cation exchange.

34. The method of claim 32 wherein said pretreatment with a cation exchange system comprises strong acid cation exchange.

35. The process of claim 32 wherein said oxidant removal pretreatment process comprises adding sodium metabisulfite to said feed water.

36. The method as set forth in claim 32, further comprising a method of utilizing said waste stream in regenerating said cation exchange system.

37. The process as set forth in claim 33, further comprising a method of regenerating said weak acid cation exchange system using said waste stream as an acid source.

38. The process as set forth in claim 34, further comprising a method of regenerating said strong acid cation exchange system using said waste stream as an acid source.

39. A method of treating a feedwater stream in a membrane separation device to produce a product stream having a reduced solute content and a reject stream having a higher solute content, wherein said membrane separation device comprises either a reverse osmosis membrane or a nanofiltration membrane, wherein said method comprises:

(a) providing a feedwater stream having solutes therein;

(b) adjusting the pH of said feedwater stream, if necessary, to ensure that at least some free inorganic acidity is present in said feedwater stream to produce a pretreated feedwater stream;

(c) passing said pretreated feedwater stream from step (b) above through said membrane separation device, said pretreated feedwater stream having a preselected pH, said membrane separation device substantially blocking passage of at least some dissolved species to concentrate said pretreated feedwater to a preselected concentration factor to produce

(i) A waste stream containing a major solute and having a pH less than the pH of the pretreated feedwater stream, and

(ii) a less solubles containing product stream having a pH greater than the pH of the pretreated feedwater stream.

40. A process in accordance with claim 1 or claim 39, wherein said solute in said feedwater stream comprises at least one component that causes membrane fouling in the absence of free inorganic acidity.

41. The method of claim 1, wherein said solutes in said feedwater comprise cations and anions, and wherein said feedwater is softened prior to passing said pretreated feedwater stream through said membrane separation device.

42. A method of treating a feedwater stream in a membrane separation device, the membrane separation device including a reverse osmosis membrane, to produce a low solute containing product stream and a high solute containing reject stream, the method comprising:

(a) providing a feedwater stream comprising a solute comprising (i) a cation,

(ii) (ii) an anion, and (iii) one or more non-ionized species, wherein the one or more non-ionized species comprise isopropanol or acetone;

(b) adjusting the pH of the feedwater to a pH of 4.3 or less, if necessary, to ensure that at least some free inorganic acidity is present in the feedwater to provide a pretreated feedwater stream;

(d) passing said pretreated feedwater through said membrane separation device, said membrane separation device substantially preventing passage of at least some dissolved species, to concentrate said feedwater to a preselected concentration factor to produce

(i) A waste stream containing more solutes and having a pH lower than said pretreated feedwater stream, and

(ii) a less soluble product stream having a pH greater than the pretreated feedwater stream.

43. The method of claim 42, wherein the pH of the feed water is or is adjusted to 2.6 or less.

44. The process as set forth in claim 42 or 43 wherein said non-ionized species comprises at least one Total Organic Carbon (TOC) component, and wherein said at least one Total Organic Carbon (TOC) component is effectively removed from said product stream to a level of 10% or less of the concentration of such component in said feed water.

45. The process as set forth in claim 42 wherein said product stream contains free inorganic acidity, and wherein said process further comprises treating said product stream in an anion exchange system effective to remove free inorganic acidity from said product stream.

46. The process of claim 45 wherein said anion exchange system is selected from one or more of the following: (a) a weak base anion exchange system, (b) a medium base anion exchange system, and (c) a strong base anion exchange system.

47. The method of claim 44 further comprising adding ferric or ferrous ions to the feed water as a reactant to facilitate removal of TOC prior to the feed water entering a membrane separation device comprising a reverse osmosis membrane.

48. The process as set forth in claim 42 wherein said non-ionized species comprises a total organic carbon component, wherein said process further comprises the step of irradiating said feedwater stream with a UV light source, and wherein said total organic carbon component is effectively removed from said product stream.

49. The process as set forth in claim 42 wherein said non-ionized species comprises a total organic carbon component and said process further comprises ozonating said product stream with an ozone-containing gas wherein said total organic carbon component is effectively removed from said product stream.

50. The process of claim 42 wherein the ratio of the amount of said produced product stream to the amount of said provided feedwater stream is 90% or greater.

51. The process of claim 42, wherein the ratio of the amount of said produced product stream to the amount of said provided feedwater stream is 95% or greater.