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SYSTEM AND METHODS FOR CONCENTRATING DISSOLVED SOLIDS IN AN AQUEOUS SOLUTION

20260115664 ยท 2026-04-30

    Inventors

    Cpc classification

    International classification

    Abstract

    System and process for concentrating dissolved solids in an aqueous solution. The system contains a first nanofiltration unit, a second nanofiltration unit in fluid communication with the first nanofiltration unit, and a reverse osmosis unit. Each nanofiltration unit may contain a plurality of nanofiltration membranes. The plurality of nanofiltration membranes may include a first nanofiltration membrane located upstream from a second nanofiltration unit where the first nanofiltration membrane has a higher salt rejection and higher water rejection rate than the second nanofiltration unit.

    Claims

    1. A system for concentrating dissolved solids in an aqueous solution, the system comprising: a first nanofiltration unit comprising a first nanofiltration membrane, a first feed inlet in fluid communication with an aqueous solution source comprising a brine, a first concentrate outlet, and a first permeate outlet; a second nanofiltration unit comprising a second nanofiltration membrane, a second feed inlet in fluid communication with the first concentrate outlet, a second concentrate outlet, and a second permeate outlet; and a reverse osmosis unit comprising a reverse osmosis membrane, a reverse osmosis feed inlet in fluid communication with the second concentrate outlet, a reverse osmosis concentrate outlet, and a reverse osmosis permeate outlet.

    2. The system of claim 1, wherein the second permeate outlet is in fluid communication with the aqueous solution source.

    3. The system of claim 1, wherein the reverse osmosis unit is an osmotically assisted reverse osmosis unit.

    4. The system of claim 1, wherein the system further comprises a high pressure pump in fluid communication with the second concentrate outlet and the reverse osmosis feed inlet.

    5. The system of claim 1, wherein the first nanofiltration unit comprises more than one nanofiltration membranes.

    6. The system of claim 5, wherein a first of the one of the more than one nanofiltration membranes of the first nanofiltration unit has a lower water and salt permeability than a second of the more than one nanofiltration membranes of the first nanofiltration unit.

    7. The system of claim 6, wherein the first of the more than one nanofiltration membranes of the first nanofiltration unit is in fluid communication with the first feed inlet and a first inter nanofiltration unit outlet and the second of the more than one nanofiltration membranes of the first nanofiltration unit is in fluid communication with the first inter nanofiltration unit outlet and the first concentrate outlet.

    8. The system of claim 6, wherein the first of the more than one nanofiltration membranes of the first nanofiltration unit has a salt permeability of 0.5 L/(m.sup.2h) to 100 L/(m.sup.2h) and a water permeability of 0.05 L/(m.sup.2.Math.h.Math.bar) to 1.5 L/(m.sup.2.Math.h.Math.bar), and the second of the more than one nanofiltration membranes of the first nanofiltration unit has a salt permeability of greater than 100 L/(m.sup.2h) to 400 L/(m.sup.2h) and a water permeability of greater than 1.5 L/(m.sup.2.Math.h.Math.bar) to 5 L/(m.sup.2.Math.h.Math.bar).

    9. The system of claim 1, wherein the second nanofiltration membrane comprises more than one nanofiltration membranes.

    10. The system of claim 9, wherein a first of the more than one nanofiltration membranes of the second nanofiltration unit has a lower water and salt permeability than a second of the more than one nanofiltration membranes of the second nanofiltration unit.

    11. The system of claim 10, wherein the first of the more than one nanofiltration membranes of the second nanofiltration unit is in fluid communication with the second feed inlet and a second inter nanofiltration unit outlet and the second of the more than one nanofiltration membranes of the second nanofiltration unit is in fluid communication with the second inter nanofiltration unit outlet and the second concentrate outlet.

    12. The system of claim 10, wherein the first of the more than one nanofiltration membranes of the second nanofiltration unit has a salt permeability of 0.5 L/(m.sup.2h) to 100 L/(m.sup.2h) and a water permeability of 0.05 L/(m.sup.2.Math.h.Math.bar) to 1.5 L/(m.sup.2.Math.h.Math.bar), and the second of the more than one nanofiltration membranes of the second nanofiltration unit has a salt permeability of greater than 100 L/(m.sup.2h) to 400 L/(m.sup.2h) and a water permeability of greater than 1.5 L/(m.sup.2.Math.h.Math.bar) to 5 L/(m.sup.2.Math.h.Math.bar).

    13. The system of claim 1, wherein the reverse osmosis membrane is a high rejection osmotically assisted reverse osmosis membrane having a salt permeability of 0.5 to 30 L/(m.sup.2.Math.h) and a water permeability of 0.05 to 3 L/(m.sup.2.Math.h.Math.bar).

    14. The system of claim 1, wherein the first nanofiltration unit is configured to be operated at a pressure of 25 to 45 bar.

    15. The system of claim 1, wherein the second nanofiltration unit is configured to be operated at a pressure of 25 to 45 bar.

    16. The system of claim 1, wherein the reverse osmosis unit is configured to be operated at a pressure of 65 to 80 bar.

    17. A method for concentrating dissolved solids in an aqueous solution source using the system of claim 1, the method comprising the steps of: flowing a brine through the first feed inlet to separate ions from the brine to form a first concentrate and a first permeate; flowing the first concentrate through the second feed inlet to separate ions from the first concentrate to form a second concentrate and a section permeate; and flowing the second concentrate through the reverse osmosis feed inlet to separate ions from the second concentrate to form a reverse osmosis concentrate and a reverse osmosis permeate.

    18. The method of claim 17, wherein the brine comprises 70,000 to 90,000 mg/L total dissolved solids (TDS).

    19. The method of claim 17, wherein the second concentrate comprises 100,000 to 140,000 mg/L TDS.

    20. The method of claim 17, wherein the reverse osmosis concentrate comprises 160,000 to 200,000 mg/L TDS.

    Description

    BRIEF DESCRIPTION OF THE DRAWINGS

    [0040] Advantages of the present invention may become apparent to those skilled in the art with the benefit of the following detailed description and upon reference to the accompanying drawings. While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings. The drawings may not be to scale.

    [0041] FIG. 1: Schematic of a system for concentrating dissolved solids in an aqueous solution according to an example of the present disclosure is shown.

    [0042] FIG. 2: Schematic of a system for concentrating dissolved solids in an aqueous solution according to another example of the present disclosure is shown.

    [0043] FIG. 3: Schematic of a system for concentrating dissolved solids in an aqueous solution according to another example of the present disclosure is shown.

    [0044] FIG. 4: Schematic of a system for concentrating dissolved solids in an aqueous solution according to another example of the present disclosure is shown.

    [0045] FIG. 5: Schematic of a desalination system according to an example of the present disclosure is shown.

    [0046] FIG. 6: A flow chart of the method steps employed for a method for concentrating dissolved solids in an aqueous solution using the system shown in FIGS. 1-3.

    [0047] FIG. 7: A flow chart of the method steps employed for a method for concentrating dissolved solids in an aqueous solution using the system shown in FIG. 4.

    DETAILED DESCRIPTION

    [0048] A discovery has been made that provides a system and process for concentrating brine. The system includes a hybrid nanofiltration reverse osmosis system. The hybrid system can concentrate a brine solution in a two stage nanofiltration process followed by a reverse osmosis process. The reverse osmosis process can in some aspects be an osmotically assisted reverse osmosis (OARO) system. The brine solution can be a byproduct of desalination of saline water. The desalination brine byproduct can have a concentration of 70,000 to 90,000 mg/L TDS. The two stage nanofiltration process can concentrate the desalination brine byproduct at a pressure of 30 to 40 bar to produce a retentate having a concentration of 100,000 to 140,000 mg/L TDS. The reverse osmosis process can further concentrate the retentate from the two stage nanofiltration process at a pressure of 70 to 85 bar to produce a concentrated brine having a concentration of 160,000 to 200,0000 mg/L TDS. Each stage of the two stage nanofiltration process can contain a high rejection nanofiltration membrane and a low rejection nanofiltration membrane. Water permeability of the high rejection nanofiltration membrane can be lower that the water permeability of the low rejection nanofiltration membrane. Salt permeability of the high rejection nanofiltration membrane can be lower than the salt permeability of the low rejection nanofiltration membrane.

    [0049] These and other non-limiting aspects of the present disclosure are discussed in further detail in the following sections.

    [0050] Referring to FIG. 1, a schematic of a system, 100a, for concentrating dissolved solids in an aqueous solution according to an example of the present disclosure is shown. The system 100 includes a first nanofiltration unit 110, a second nanofiltration unit 120, and a reverse osmosis unit 130.

    [0051] The first nanofiltration unit 110 in system 100a can contain a first nanofiltration membrane 112, a first feed inlet 111, a first concentrate outlet 114, and a first permeate outlet 113. The first feed inlet 111 can be in a fluid communication with an aqueous solution source (shown in FIG. 4). The first nanofiltration membrane 112 can be in a fluid communication with the first feed inlet 111, the first concentrate outlet 114, and the first permeate outlet 113. An aqueous solution 140 from the aqueous solution source (shown in FIG. 4) can be flowed through the first feed inlet 111 and can be contacted with the first nanofiltration membrane 112 to separate ions from the aqueous solution 140 and form a first concentrate 142 and a first permeate 141. The first concentrate 142 can contain a retentate, and the first permeate 141 can contain a permeate from nanofiltration of the aqueous solution 140 using the first nanofiltration membrane 112. The first concentrate 142 can be flowed out of the first nanofiltration unit 110 through the first concentrate outlet 114, and the first permeate 141 can be flowed out of the first nanofiltration unit 110 through the first permeate outlet 113.

    [0052] The second nanofiltration unit 120, in system 100a, can contain a second nanofiltration membrane 122, a second feed inlet 121, a second concentrate outlet 124, and a second permeate outlet 123. The second feed inlet 121 can be in a fluid communication with the first concentrate outlet 114. The second nanofiltration membrane 122 can be in a fluid communication with the second feed inlet 121, the second concentrate outlet 124, and the second permeate outlet 123. The first concentrate 142 can be flowed through the second feed inlet 121 and can be contacted with the second nanofiltration membrane 122 to separate ions from the first concentrate 142 and form a second concentrate 143 and a second permeate 144. The second concentrate 143 can contain a retentate, and the second permeate 144 can contain a permeate from nanofiltration of the first concentrate 142 using the second nanofiltration membrane 122. The second concentrate 143 can be flowed out of the second nanofiltration unit 120 through the second concentrate outlet 124, and the second permeate 144 can be flowed out of the second nanofiltration unit 120 through the second permeate outlet 123.

    [0053] The reverse osmosis unit 130, in system 100a, can contain a reverse osmosis membrane 132, a reverse osmosis feed inlet 131, a reverse osmosis concentrate outlet 134, and a reverse osmosis permeate outlet 133. The reverse osmosis feed inlet 131 can be in a fluid communication with the second concentrate outlet 124. The reverse osmosis membrane 132 can be in a fluid communication with the reverse osmosis feed inlet 131, the reverse concentrate outlet 134, and the reverse permeate outlet 133. The second concentrate 143 can be flowed through the reverse osmosis feed inlet 131 and can be contacted with the reverse osmosis membrane 132 to separate ions from the second concentrate 143 and form a reverse osmosis concentrate 145 and a reverse osmosis permeate 146. The reverse osmosis concentrate 145 can contain a retentate, and the reverse osmosis permeate 146 can contain a permeate from reverse osmosis, such as osmotically assisted reverse osmosis of the second concentrate 143 using the reverse osmosis membrane 132. If the reverse osmosis unit is an osmotically assisted reverse osmosis unit, then the reverse osmosis unit 130 would additionally contain a draw solution inlet (not shown) that is in fluid communication with the reverse osmosis permeate outlet 133, a draw solution (not shown) can be flowed through the draw solution inlet, contact the reverse osmosis membrane 132, draw water from the second concentrate 143 through the reverse osmosis membrane 132, and be flowed out of the reverse osmosis unit 130 through the reverse osmosis permeate outlet 133. The reverse osmosis concentrate 145 can be flowed out of the reverse osmosis unit 130 through the reverse osmosis concentrate outlet 134, and the reverse osmosis permeate 146 can be flowed out of the reverse osmosis unit 130 through the reverse osmosis permeate outlet 133.

    [0054] Referring to FIG. 2, a schematic of a system, 100b, for concentrating dissolved solids in an aqueous solution according to an example of the present disclosure is shown. The system 100b includes a first nanofiltration unit 110, a second nanofiltration unit 120, and a reverse osmosis unit 130.

    [0055] The first nanofiltration unit 110 of the system 100b can contain a first feed inlet 111, a first concentrate outlet 114, a first permeate outlet 113, a first inter nanofiltration unit outlet 115, and more than one first nanofiltration membranes 112a and 112b. The first feed inlet 111 can be in a fluid communication with an aqueous solution source (shown in FIG. 4). The more than one first nanofiltration membranes can contain a first membrane 112a, and a second membrane 112b. The nanofiltration membrane 112a can be in a fluid communication with the first feed inlet 111, and the first inter nanofiltration unit outlet 115. The nanofiltration membrane 112b can be in a fluid communication with the first inter nanofiltration unit outlet 115, the first concentrate outlet 114, and the first permeate outlet 113. An aqueous solution 140 can be flowed through the first feed inlet 111 and can be contacted with the nanofiltration membrane 112a to separate ions from the aqueous solution 140 and form a first intermediate concentrate 147. The first intermediate concentrate 147 can contain a retentate from nanofiltration of the aqueous solution 140 using the nanofiltration membrane 112a. The first intermediate concentrate 147 can be flowed through the first inter nanofiltration unit outlet 115 and can be contacted with the nanofiltration membrane 112b to separate ions from the first intermediate concentrate and form a first concentrate 142, and a first permeate 141. The first concentrate 142 can contain a retentate, and the first permeate 141 can contain a permeate from nanofiltration of the first intermediate concentrate 147 using the nanofiltration membrane 112b. The first concentrate 142 can be flowed out of the first nanofiltration unit 110 through the first concentrate outlet 114, and the first permeate 141 can be flowed out of the first nanofiltration unit 110 through the first permeate outlet 113.

    [0056] The second nanofiltration unit 120 of the system 100b can contain a second feed inlet 121, a second concentrate outlet 124, a second permeate outlet 123, a second inter nanofiltration unit outlet 125, and more than one second nanofiltration membranes 122a and 122b. The more than one second nanofiltration membranes contain a first membrane 122a, and a second membrane 122b. The nanofiltration membrane 122a can be in a fluid communication with the second feed inlet 121, and the second inter nanofiltration unit outlet 125. The nanofiltration membrane 122b can be in a fluid communication with the second inter nanofiltration unit outlet 125, the second concentrate outlet 124, and the second permeate outlet 123. The first concentrate 142 can be flowed through the second feed inlet 121 and can be contacted with the nanofiltration membrane 122a to separate ions from the first concentrate 142 and form a second intermediate concentrate 148. The second intermediate concentrate 148 can contain a retentate from nanofiltration of the first concentrate 142 using the nanofiltration membrane 122a. The second intermediate concentrate 148 can be flowed through the second inter nanofiltration unit outlet 125 and can be contacted with the nanofiltration membrane 122b to separate ions from the second intermediate concentrate 148 and form a second concentrate 143, and a second permeate 144. The second concentrate 143 can contain a retentate, and the second permeate 144 can contain a permeate from nanofiltration of the second intermediate concentrate 148 using the nanofiltration membrane 122b. The second concentrate 143 can be flowed out of the second nanofiltration unit 120 through the second concentrate outlet 124, and the second permeate 144 can be flowed out of the second nanofiltration unit 120 through the second permeate outlet 123. The second permeate outlet 123 can be in a fluid communication with the first feed inlet 111. The second permeate 144 can be mixed with aqueous solution 140 and contacted with the membrane 112a.

    [0057] The reverse osmosis unit 130 of the system 100b can have the same configuration and process of operation as that described for the reverse osmosis unit of the system 100a.

    [0058] Referring to FIG. 3, a schematic of a system 100c for concentrating dissolved solids in an aqueous solution according to an example of the present disclosure is shown. The system 100c contains a plurality of the first of the more than one first nanofiltration membranes 112a, a plurality of the second of the more than one first nanofiltration membranes 112b, a plurality of the first of the more than one second nanofiltration membranes 122a, and a plurality of the second of the more than one second nanofiltration membranes 122b. The plurality of the nanofiltration membranes 112a can be fluidly connected in series, and the aqueous solution 140 can be nano filtered using the plurality of the nanofiltration membranes 112a to produce the first intermediate concentrate 147. The plurality of the nanofiltration membranes 112b can be fluidly connected in series, and the first intermediate concentrate 147 can be nano filtered using the plurality of the nanofiltration membranes 112b to produce the first concentrate 142, and first permeate 141. The plurality of the nanofiltration membranes 122a can be fluidly connected in series, and the first concentrate 142 can be nano filtered using the plurality of the nanofiltration membranes 122a to produce the second intermediate concentrate 148. The plurality of the nanofiltration membranes 122b can be fluidly connected in series, and the second intermediate concentrate 148 can be nano filtered using the plurality of the nanofiltration membranes 122b to produce the second concentrate 143, and second permeate 144. Although, three first of the more than one first nanofiltration membranes 112a.sub.1, 112a.sub.2, 112a.sub.3 are shown in FIG. 3, any suitable number, one or more, of the first of the more than one first nanofiltration membranes 112a can be used. Although, three second of the more than one first nanofiltration membranes 112b.sub.1, 112b.sub.2, 112b.sub.3 are shown in FIG. 3, any suitable number, one or more, of the second of the more than one first nanofiltration membranes 112b can be used. Although, three first of the more than one second nanofiltration membranes 122a.sub.1, 122a.sub.2, 122a.sub.3 is shown in FIG. 3, any suitable number, one or more, of the first of the more than one second nanofiltration membranes 122a can be used. Although, three second of the more than one second nanofiltration membranes 122b.sub.1, 122b.sub.2, 122b.sub.3 are shown in FIG. 3, any suitable number, one or more, of the second of the more than one second nanofiltration membranes 122b can be used. The system 100c can include a high pressure pump 170 fluidly connected to the second concentrate outlet 124 and the reverse osmosis feed inlet 131. The second concentrate 143 can be pumped into the reverse osmosis unit 130 using the high pressure pump 170. The other components of the system 100c, shown in FIG. 3, can be configured and operated in the manner described for system 100b.

    [0059] Referring to FIG. 4, a schematic of a system 100d for concentrating dissolved solids in an aqueous solution according to an example of the present disclosure is shown. The system 100d contains a desalination system 150, a first nanofiltration unit 110, a second nanofiltration unit 120, and a reverse osmosis unit 130, and an optional high pressure pump 170. The desalination system 150 can be fluidly connected to the first nanofiltration unit 110. A saline solution 160 can be desalinated using the desalination system 150, and the aqueous solution 140 can contain a retentate from the desalination process. The first nanofiltration unit 110, second nanofiltration unit 120, and reverse osmosis unit 130, and an optional high pressure pump 170 of the system 100d, can be configured and operated in the manner described for system 100c.

    [0060] Referring to FIG. 5, the desalination system 150 of FIG. 4 can contain a dual-media filtration (DMF) unit 151, cartridge filtration (CF) unit 152, pre-nanofiltration unit 153, and sea water reverse osmosis (SWRO) unit 154, fluidly connected in series. The DMF unit 151 can contain a dual-media filtration membrane (not shown), the CF unit 152 can contain a cartridge filtration membrane (not shown), the pre-nanofiltration unit 153 can contain a nanofiltration membrane (not shown), and the SWRO unit 154 can contain a reverse osmosis membrane (not shown). The saline solution 160 can be fed to the DMF unit 151. In the DMF unit the saline solution 160 can be filtered and a stream 155 containing the permeate from the filtration can be fed to the CF unit 152. In the CF unit 152 the stream 155 can be filtered and a stream 156 containing the permeate from the filtration can be fed to the pre-nanofiltration unit 153. In the pre-nanofiltration unit 153 the stream 156 can be filtered and a stream 157 containing the permeate from the filtration can be fed to the SWRO unit 154. In the SWRO unit 154 the stream 157 can be filtered and the aqueous solution 140 can contain a retentate from the filtration process.

    [0061] Referring to FIG. 6, a flow chart of the method steps employed for a method 200a for concentrating dissolved solids in an aqueous solution using the system 100a-c is shown. The method 200a can include steps 201a, 202a, and 203a. In the step 201a, the aqueous solution 140 can be flowed through the first feed inlet 111 to separate ions from the aqueous solution 140 to form the first concentrate 142 and the first permeate 141. The step 201a can be performed in the first nanofiltration unit 110, of the system 100a-c. In step 202a, the first concentrate 142 can be flowed through the second feed inlet 121 to separate ions from the first concentrate 142 to form a second concentrate 143 and a second permeate 144. The step 202a can be performed in the second nanofiltration unit 120, of the system 100a-c. In step 203a, the second concentrate 143 can be flowed through the reverse osmosis feed inlet 131 to separate ions from the second concentrate 143 to form a reverse osmosis concentrate 145 and a reverse osmosis permeate 146. The step 203a can be performed in the reverse osmosis unit 130, of the system 100a-c.

    [0062] Referring to FIG. 7, a flow chart of the method steps employed for a method 200b for concentrating dissolved solids in an aqueous solution using the system 100d shown. The method 200b can include steps 201b, 201b, 202b, and 203b. In step 201b, the saline solution 160 can be desalinated using the desalination system 150 of system 100d to obtain the aqueous solution 140. In the step 201b, the aqueous solution 140 can be flowed through the first feed inlet 111 to separate ions from the aqueous solution 140 to form the first concentrate 142 and the first permeate 141. The step 201b can be performed in the first nanofiltration unit 110, of the system 100d. In step 202b, the first concentrate 142 can be flowed through the second feed inlet 121 to separate ions from the first concentrate 142 to form a second concentrate 143 and a second permeate 144. The step 202b can be performed in the second nanofiltration unit 120, of the system 100d. In step 203b, the second concentrate 143 can be flowed through the reverse osmosis feed inlet 131 to separate ions from the second concentrate 143 to form a reverse osmosis concentrate 145 and a reverse osmosis permeate 146. The step 203b can be performed in the reverse osmosis unit 130, of the system 100d.

    [0063] The nanofiltration membrane 112a can have a lower salt permeability than the salt permeability of the nanofiltration membrane 112b. The nanofiltration membrane 122a can have a lower salt permeability than the salt permeability of the nanofiltration membrane 122b. In certain embodiments, the nanofiltration membrane 112a and/or 122a has a salt permeability of 0.5 to 100 L/(m.sup.2.Math.h). In certain embodiments, the nanofiltration membrane 112a and/or 122a has a salt permeability of 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 5, 6.5, 7, 7.5, 8, 8.5, 9, 10, 20, 30, 40, 50, 60, 70, 80, 90, or 100 L/(m.sup.2.Math.h) or any range or value therebetween. In certain embodiments, the nanofiltration membrane 112a and/or 122a has a salt permeability of 0.5 to 80 L/(m.sup.2.Math.h); 0.5 to 60 L/(m.sup.2.Math.h); 0.5 to 40 L/(m.sup.2.Math.h); 0.5 to 20 L/(m.sup.2.Math.h); 0.5 to 10 L/(m.sup.2.Math.h); 0.5 to 8 L/(m.sup.2.Math.h); 0.5 to 6 L/(m.sup.2.Math.h); 0.5 to 5 L/(m.sup.2.Math.h); 0.5 to 4 L/(m.sup.2.Math.h); 1 to 100 L/(m.sup.2.Math.h); 1 to 80 L/(m.sup.2.Math.h); 1 to 60 L/(m.sup.2.Math.h); 1 to 40 L/(m.sup.2.Math.h); 1 to 20 L/(m.sup.2.Math.h); 1 to 10 L/(m.sup.2.Math.h); 1 to 8 L/(m.sup.2.Math.h); 1 to 6 L/(m.sup.2.Math.h); 1 to 5 L/(m.sup.2.Math.h); 1 to 4 L/(m.sup.2.Math.h); 2 to 100 L/(m.sup.2.Math.h); 2 to 80 L/(m.sup.2.Math.h); 2 to 60 L/(m.sup.2.Math.h); 2 to 40 L/(m.sup.2.Math.h); 2 to 20 L/(m.sup.2.Math.h); 2 to 10 L/(m.sup.2.Math.h); 2 to 8 L/(m.sup.2.Math.h); 2 to 6 L/(m.sup.2.Math.h); 2 to 5 L/(m.sup.2.Math.h); 2 to 4 L/(m.sup.2.Math.h); 3 to 100 L/(m.sup.2.Math.h); 3 to 80 L/(m.sup.2.Math.h); 3 to 60 L/(m.sup.2.Math.h); 3 to 40 L/(m.sup.2.Math.h); 3 to 20 L/(m.sup.2.Math.h); 3 to 10 L/(m.sup.2.Math.h); 3 to 8 L/(m.sup.2.Math.h); 3 to 6 L/(m.sup.2.Math.h); 3 to 5 L/(m.sup.2.Math.h); or 3 to 4 L/(m.sup.2.Math.h). The salt permeability of the different nanofiltration membranes of the plurality of the nanofiltration membranes 112a and/or 122a in system 100c and 100d can be the same or different. As an illustrative non limiting example the salt permeability of 112a.sub.1, 112a.sub.2, and 112a.sub.3 (in the system 100c and 100d) and/or 122a.sub.1, 122a.sub.2, and 122a.sub.3 (in the system 100c and 100d) are the same and are in the range 0.5 to 100 L/(m.sup.2.Math.h). In another illustrative non limiting example, in the system 100c and 100d the salt permeability of 112a.sub.1 is the same as that of 112a.sub.2, but is different from that of 112a.sub.3, and/or the salt permeability of 122a.sub.1 is the same as that of 122a.sub.2, but is different from that of 122a.sub.3, where the salt permeability of the membranes 112a.sub.1, 112a2, 112a3, 122a.sub.1, 122a.sub.2, and 122a.sub.3 all are in the range 0.5 to 100 L/(m.sup.2.Math.h). In another illustrative non limiting example, in the system 100c and 100d the salt permeability of 112a.sub.1, 112a.sub.2, and 112a.sub.3 are different and/or salt permeability of 122a.sub.1, 122a.sub.2, and 122a.sub.3 are different, where the salt permeability of the membranes 112a.sub.1, 112a.sub.2, 112a.sub.3, 122a.sub.1, 122a.sub.2, and 122a3 all are in the range 0.5 to 100 L/(m.sup.2.Math.h).

    [0064] The nanofiltration membrane 112a can have lower water permeability than the water permeability of 112b. The nanofiltration membrane 122a can have a lower water permeability than the water permeability of the nanofiltration membrane 122b. In certain embodiments, the nanofiltration membrane 112a and/or 122a has a water permeability of 0.05 to 1.5 L/(m.sup.2.Math.h.Math.bar). In certain embodiments, the nanofiltration membrane 112a and/or 122a has a water permeability of 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4 or 1.5 L/(m.sup.2.Math.h.Math.bar) or any range or value therebetween. In certain embodiments, the nanofiltration membrane 112a and/or 122a has a water permeability of 0.05 to 1.5 L/(m.sup.2.Math.h.Math.bar); 0.05 to 1 L/(m.sup.2.Math.h.Math.bar); 0.05 to 0.8 L/(m.sup.2.Math.h.Math.bar); 0.05 to 0.5 L/(m.sup.2.Math.h.Math.bar); 0.1 to 1.5 L/(m.sup.2.Math.h.Math.bar); 0.1 to 1 L/(m.sup.2.Math.h.Math.bar); 0.1 to 0.8 L/(m.sup.2.Math.h.Math.bar); 0.1 to 0.5 L/(m.sup.2.Math.h.Math.bar); 0.2 to 1.5 L/(m.sup.2.Math.h.Math.bar); 0.2 to 1 L/(m.sup.2.Math.h.Math.bar); 0.2 to 0.8 L/(m.sup.2.Math.h.Math.bar); 0.2 to 0.5 L/(m.sup.2.Math.h.Math.bar); 0.3 to 1.5 L/(m.sup.2.Math.h.Math.bar); 0.3 to 1 L/(m.sup.2.Math.h.Math.bar); 0.3 to 0.8 L/(m.sup.2.Math.h.Math.bar); or 0.3 to 0.5 L/(m.sup.2.Math.h.Math.bar). As an illustrative non limiting example the water permeability of 112a.sub.1, 112a.sub.2, and 112a.sub.3 and/or 122a.sub.1, 122a.sub.2, and 122a.sub.3 are the same and are in the range 0.05 L/(m.sup.2.Math.h.Math.bar) to 1.5 L/(m.sup.2.Math.h.Math.bar). The water permeability of the different nanofiltration membranes of the plurality of the nanofiltration membranes 112a and/or 122a in system 100c and 100d can be the same or different. In another illustrative non limiting example, in the system 100c and 100d the water permeability of 112a.sub.1 is the same as that of 112a.sub.2, but is different from that of 112a.sub.3, and/or the water permeability of 122a.sub.1 is the same as that of 122a.sub.2, but is different from that of 122a.sub.3, where the water permeability of the membranes 112a.sub.1, 112a.sub.2, 112a.sub.3, 122a.sub.1, 122a.sub.2, and 122a.sub.3 all are in the range 0.05 L/(m.sup.2.Math.h.Math.bar) to 1.5 L/(m.sup.2.Math.h.Math.bar). In another illustrative non limiting example, in the system 100c and 100d the water permeability of 112a.sub.1, 112a.sub.2, and 112a.sub.3 and/or 122a.sub.1, 122a.sub.2, and 122a.sub.3 are different, where the water permeability of the membranes 112a.sub.1, 112a.sub.2, 112a.sub.3, 122a.sub.1, 122a.sub.2, and 122a.sub.3 all are in the range 0.05 L/(m.sup.2.Math.h.Math.bar) to 1.5 L/(m.sup.2.Math.h.Math.bar). Non-limiting examples of commercially available membranes that can be used as the membranes 112a and/or 122a includes CSM NE8040-90, CSM NE4040-90, CSM NE4040-90 from TORAY.

    [0065] In certain embodiments, the nanofiltration membrane 112b and/or 122b has a salt permeability of >100 L/(m.sup.2.Math.h) to 400 L/(m.sup.2.Math.h). In certain embodiments, the nanofiltration membrane 112b and/or 122b has a salt permeability of >100, 150, 200, 250, 300, 350, or 400 L/(m.sup.2.Math.h) or any value or range therebetween. In certain embodiments, the nanofiltration membrane 112b and/or 122b has a salt permeability of >100 to 400 L/(m.sup.2.Math.h); >100 to 350 L/(m.sup.2.Math.h); >100 to 300 L/(m.sup.2.Math.h); >100 to 250 L/(m.sup.2.Math.h); 150 to 400 L/(m.sup.2.Math.h); 150 to 350 L/(m.sup.2.Math.h); 150 to 300 L/(m.sup.2.Math.h); 150 to 250 L/(m.sup.2.Math.h); 200 to 400 L/(m.sup.2.Math.h); 200 to 350 L/(m.sup.2.Math.h); 200 to 300 L/(m.sup.2.Math.h); or 200 to 250 L/(m.sup.2.Math.h). The salt permeability of the different nanofiltration membranes of the plurality of the nanofiltration membranes 112b and/or 122b in system 100c and 100d can be the same or different. As an illustrative non limiting example the salt permeability of 112b.sub.1, 112b.sub.2, and 112b.sub.3 and/or 122b.sub.1, 122b.sub.2, and 122b.sub.3 (in the system 100c and 100d) are the same, and are in the range >100 L/(m.sup.2.Math.h) to 400 L/(m.sup.2.Math.h). In another illustrative non limiting example, in the system 100c and 100d the salt permeability of 112b.sub.1 is the same as that of 112b.sub.2, but is different from that of 112b.sub.3, and/or 122b.sub.1 is the same as that of 122b.sub.2, but is different from that of 122b.sub.3, where salt permeability of the membranes 112b.sub.1, 112b.sub.2, 112b.sub.3, 122b.sub.1, 122b.sub.2, and 122b.sub.3 all are in the range >100 L/(m.sup.2.Math.h) to 400 L/(m.sup.2.Math.h). In another illustrative non limiting example, in the system 100c and 100d the salt permeability of 112b.sub.1, 112b.sub.2, and 112b.sub.3 and/or 122b.sub.1, 122b.sub.2, and 122b.sub.3 are different, where salt permeability of the membranes 112b.sub.1, 112b.sub.2, 112b.sub.3, 122b.sub.1, 122b.sub.2, and 122b.sub.3, all are in the range >100 L/(m.sup.2.Math.h) to 400 L/(m.sup.2.Math.h).

    [0066] In certain embodiments, the nanofiltration membrane 112b and/or 122b has a water permeability of >1.5 to 5 L/(m.sup.2.Math.h.Math.bar). In certain embodiments, the nanofiltration membrane 112b and/or 122b has a water permeability of >1.5, 2, 2.5, 3, 3.5, 4, 4.5 or 5 L/(m.sup.2.Math.h.Math.bar) or any range or value therebetween. In certain embodiments, the nanofiltration membrane 112b and/or 122b has a water permeability of >1.5 to 5 L/(m.sup.2.Math.h.Math.bar); >1.5 to 4 L/(m.sup.2.Math.h.Math.bar); >1.5 to 3.5 L/(m.sup.2.Math.h.Math.bar); >1.5 to 3 L/(m.sup.2.Math.h.Math.bar); 2 to 5 L/(m.sup.2.Math.h.Math.bar); 2 to 4 L/(m.sup.2.Math.h.Math.bar); 2 to 3.5 L/(m.sup.2.Math.h.Math.bar); 2 to 3 L/(m.sup.2.Math.h.Math.bar); 2.5 to 5 L/(m.sup.2.Math.h.Math.bar); 2.5 to 4 L/(m.sup.2.Math.h.Math.bar); 2.5 to 3.5 L/(m.sup.2.Math.h.Math.bar); or 2.5 to 3 L/(m.sup.2.Math.h.Math.bar). The water permeability of the different nanofiltration membranes of the plurality of the nanofiltration membranes 112b and/or 122b in system 100c and 100d can be the same or different. As an illustrative non limiting example the water permeability of 112b.sub.1, 112b.sub.2, and 112b.sub.3 and/or 122b.sub.1, 122b.sub.2, and 122b.sub.3 (in the system 100c and 100d) are the same, and are in the range >1.5 L/(m.sup.2.Math.h.Math.bar) to 5 L/(m.sup.2.Math.h.Math.bar). In another illustrative non-limiting example, in the system 100c and 100d the water permeability of 112b.sub.1 is the same as that of 112b.sub.2, but is different from that of 112b.sub.3, and/or 122b.sub.1 is the same as that of 122b.sub.2, but is different from that of 122b.sub.3, where the water permeability of the membranes 112b.sub.1, 112b.sub.2, 112b.sub.3, 122b.sub.1, 122b.sub.2, and 122b.sub.3 all are in the range >1.5 L/(m.sup.2.Math.h.Math.bar) to 5 L/(m.sup.2.Math.h.Math.bar). In another illustrative non limiting example, in the system 100c and 100d the water permeability of 112b.sub.1, 112b.sub.2, and 112b.sub.3 and/or 122b.sub.1, 122b.sub.2, and 122b.sub.3 are different, where the water permeability of the membranes 112b.sub.1, 112b.sub.2, 112b.sub.3, 122b.sub.1, 122b.sub.2, and 122b.sub.3 all are in the range >1.5 L/(m.sup.2.Math.h.Math.bar) to 5 L/(m.sup.2.Math.h.Math.bar). In the system 100c and 100d, the number of membranes 112a and/or 122a and the number of membranes 112b and/or 122b can be the same or different. Non-limiting examples of commercially available membranes that can be used as the membranes 112b includes DuPont-Filmtec NF-4040 from DUPONT.

    [0067] In the system 100c and/or 100d, the number of membranes 112a and the number of membranes 122a can be the same or different. In the system 100c and/or 100d, the number of membranes 112b and the number of membranes 122b can be the same or different.

    [0068] The saline solution 160 can be brackish water, marine water, saline industrial waste water, or any combination thereof. Brackish water can have a salt concentration of 5,000 to 30,000 ppm. Marine water can have a salt concentration of 30,000 ppm to 50,000 ppm. Saline industrial waste water can be an industrial waste water having a salt concentration of 5,000 ppm to 50,000 ppm. Salt contained in brackish water, marine water, saline industrial waste water, and brine can primarily be sodium chloride.

    [0069] In certain embodiments, the aqueous solution 140 contains a brine solution. The brine solution can be a byproduct from a desalination process. In certain embodiments, the aqueous solution 140, in the system 100a-d, is flowed through the first feed inlet 111 at a flow rate of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25 m.sup.3/h or any range or value therein. In certain embodiments, the aqueous solution 140, in the system 100a-d, is flowed through the first feed inlet 111 at a flow rate of 1 to 25 m.sup.3/h; 2 to 20 m.sup.3/h; 5 to 15 m.sup.3/h; 7.5 to 12.5 m.sup.3/h or any range or value therein. In certain embodiments, the aqueous solution 140 contains 70,000 to 90,000 mg/L total dissolved solids (TDS). In certain embodiments, the aqueous solution 140 contains 50,000 to 100,000 mg/L TDS; 60,000 to 90,000 mg/L TDS; 70,000 to 90,000 mg/L TDS; 70,000 to 85,000 mg/L TDS; 70,000 to 80,000 mg/L TDS; 75,000 to 85,000 mg/L TDS; or 75,000 to 80,000 mg/L TDS. In certain embodiments, the aqueous solution 140 contains 50,000, 55,000, 60,000, 65,000, 70,000, 71,000, 72,000, 73,000, 74,000, 75,000, 76,000, 77,000, 78,000, 79,000, 80,000, 81,000, 82,000, 83,000, 84,000, 85,000, 90,000, 95,000, or 100,000 mg/L TDS or any range or values therebetween.

    [0070] In certain embodiments, the second concentrate 143, in the system 100a-d, is flowed through the reverse osmosis inlet 131 at a flow rate of 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 m.sup.3/h or any range or value therein. In certain embodiments, the second concentrate 143 is flowed through the reverse osmosis inlet at a flow rate of 0.5 to 10 m.sup.3/h; 1 to 8 m.sup.3/h; 1 to 5 m.sup.3/h; 2 to 8 m.sup.3/h; 2 to 5 m.sup.3/h; or 2 to 3 m.sup.3/h. In certain embodiments, the second concentrate 143 contains 100,000 mg/L TDS to 140,000 mg/L TDS. In certain embodiments, the second concentrate 143 contains 100,000 mg/L TDS to 105,000 mg/L TDS, 100,000 mg/L TDS to 110,000 mg/L TDS, 100,000 mg/L TDS to 115,000 mg/L TDS, 100,000 mg/L TDS to 120,000 mg/L TDS, 100,000 mg/L TDS to 125,000 mg/L TDS, 100,000 mg/L TDS to 130,000 mg/L TDS, 100,000 mg/L TDS to 135,000 mg/L TDS, 100,000 mg/L TDS to 140,000 mg/L TDS, 105,000 mg/L TDS to 110,000 mg/L TDS, 105,000 mg/L TDS to 115,000 mg/L TDS, 105,000 mg/L TDS to 120,000 mg/L TDS, 105,000 mg/L TDS to 125,000 mg/L TDS, 105,000 mg/L TDS to 130,000 mg/L TDS, 105,000 mg/L TDS to 135,000 mg/L TDS, 105,000 mg/L TDS to 140,000 mg/L TDS, 110,000 mg/L TDS to 115,000 mg/L TDS, 110,000 mg/L TDS to 120,000 mg/L TDS, 110,000 mg/L TDS to 125,000 mg/L TDS, 110,000 mg/L TDS to 130,000 mg/L TDS, 110,000 mg/L TDS to 135,000 mg/L TDS, 110,000 mg/L TDS to 140,000 mg/L TDS, 115,000 mg/L TDS to 120,000 mg/L TDS, 115,000 mg/L TDS to 125,000 mg/L TDS, 115,000 mg/L TDS to 130,000 mg/L TDS, 115,000 mg/L TDS to 135,000 mg/L TDS, 115,000 mg/L TDS to 140,000 mg/L TDS, 120,000 mg/L TDS to 125,000 mg/L TDS, 120,000 mg/L TDS to 130,000 mg/L TDS, 120,000 mg/L TDS to 135,000 mg/L TDS, 120,000 mg/L TDS to 140,000 mg/L TDS, 125,000 mg/L TDS to 130,000 mg/L TDS, 125,000 mg/L TDS to 135,000 mg/L TDS, 125,000 mg/L TDS to 140,000 mg/L TDS, 130,000 mg/L TDS to 135,000 mg/L TDS, 130,000 mg/L TDS to 140,000 mg/L TDS, or 135,000 mg/L TDS to 140,000 mg/L TDS. In certain embodiments, the second concentrate 143 contains 100,000 mg/L TDS, 105,000 mg/L TDS, 110,000 mg/L TDS, 115,000 mg/L TDS, 120,000 mg/L TDS, 125,000 mg/L TDS, 130,000 mg/L TDS, 135,000 mg/L TDS, or 140,000 mg/L TDS. In certain embodiments, the second concentrate 143 contains at least 100,000 mg/L TDS, 105,000 mg/L TDS, 110,000 mg/L TDS, 115,000 mg/L TDS, 120,000 mg/L TDS, 125,000 mg/L TDS, 130,000 mg/L TDS, or 135,000 mg/L TDS.

    [0071] In certain embodiments, the reverse osmosis concentrate 145 has a flow rate of 0.1 m.sup.3/h to 10 m.sup.3/h, 0.1 m.sup.3/h to 7.5 m.sup.3/h, 0.1 m.sup.3/h to 5 m.sup.3/h, 0.1 m.sup.3/h to 2.5 m.sup.3/h, 0.1 m.sup.3/h to 2 m.sup.3/h, 0.1 m.sup.3/h to 1.5 m.sup.3/h, 0.5 m.sup.3/h to 7.5 m.sup.3/h, 0.5 m.sup.3/h to 5 m.sup.3/h, 0.5 m.sup.3/h to 2.5 m.sup.3/h, 0.5 m.sup.3/h to 2 m.sup.3/h, or 0.5 m.sup.3/h to 1.5 m.sup.3/h. In certain embodiments, the reverse concentrate 145 has a flow rate of 0.1, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 2, 3, 4, 5, 6, 7, 8, 9 or 10 m.sup.3/h, or any value or range therebetween. In certain embodiments, the reverse osmosis concentrate 145 contains 160,000 to 200,000 mg/L TDS. In certain embodiments, the reverse osmosis concentrate 145 contains 150,000 mg/L TDS to 210,000 mg/L TDS. In certain embodiments, the reverse osmosis concentrate 145 contains 150,000 mg/L TDS to 155,000 mg/L TDS, 150,000 mg/L TDS to 160,000 mg/L TDS, 150,000 mg/L TDS to 165,000 mg/L TDS, 150,000 mg/L TDS to 170,000 mg/L TDS, 150,000 mg/L TDS to 175,000 mg/L TDS, 150,000 mg/L TDS to 180,000 mg/L TDS, 150,000 mg/L TDS to 185,000 mg/L TDS, 150,000 mg/L TDS to 190,000 mg/L TDS, 150,000 mg/L TDS to 195,000 mg/L TDS, 150,000 mg/L TDS to 200,000 mg/L TDS, 150,000 mg/L TDS to 210,000 mg/L TDS, 155,000 mg/L TDS to 160,000 mg/L TDS, 155,000 mg/L TDS to 165,000 mg/L TDS, 155,000 mg/L TDS to 170,000 mg/L TDS, 155,000 mg/L TDS to 175,000 mg/L TDS, 155,000 mg/L TDS to 180,000 mg/L TDS, 155,000 mg/L TDS to 185,000 mg/L TDS, 155,000 mg/L TDS to 190,000 mg/L TDS, 155,000 mg/L TDS to 195,000 mg/L TDS, 155,000 mg/L TDS to 200,000 mg/L TDS, 155,000 mg/L TDS to 210,000 mg/L TDS, 160,000 mg/L TDS to 165,000 mg/L TDS, 160,000 mg/L TDS to 170,000 mg/L TDS, 160,000 mg/L TDS to 175,000 mg/L TDS, 160,000 mg/L TDS to 180,000 mg/L TDS, 160,000 mg/L TDS to 185,000 mg/L TDS, 160,000 mg/L TDS to 190,000 mg/L TDS, 160,000 mg/L TDS to 195,000 mg/L TDS, 160,000 mg/L TDS to 200,000 mg/L TDS, 160,000 mg/L TDS to 210,000 mg/L TDS, 165,000 mg/L TDS to 170,000 mg/L TDS, 165,000 mg/L TDS to 175,000 mg/L TDS, 165,000 mg/L TDS to 180,000 mg/L TDS, 165,000 mg/L TDS to 185,000 mg/L TDS, 165,000 mg/L TDS to 190,000 mg/L TDS, 165,000 mg/L TDS to 195,000 mg/L TDS, 165,000 mg/L TDS to 200,000 mg/L TDS, 165,000 mg/L TDS to 210,000 mg/L TDS, 170,000 mg/L TDS to 175,000 mg/L TDS, 170,000 mg/L TDS to 180,000 mg/L TDS, 170,000 mg/L TDS to 185,000 mg/L TDS, 170,000 mg/L TDS to 190,000 mg/L TDS, 170,000 mg/L TDS to 195,000 mg/L TDS, 170,000 mg/L TDS to 200,000 mg/L TDS, 170,000 mg/L TDS to 210,000 mg/L TDS, 175,000 mg/L TDS to 180,000 mg/L TDS, 175,000 mg/L TDS to 185,000 mg/L TDS, 175,000 mg/L TDS to 190,000 mg/L TDS, 175,000 mg/L TDS to 195,000 mg/L TDS, 175,000 mg/L TDS to 200,000 mg/L TDS, 175,000 mg/L TDS to 210,000 mg/L TDS, 180,000 mg/L TDS to 185,000 mg/L TDS, 180,000 mg/L TDS to 190,000 mg/L TDS, 180,000 mg/L TDS to 195,000 mg/L TDS, 180,000 mg/L TDS to 200,000 mg/L TDS, 180,000 mg/L TDS to 210,000 mg/L TDS, 185,000 mg/L TDS to 190,000 mg/L TDS, 185,000 mg/L TDS to 195,000 mg/L TDS, 185,000 mg/L TDS to 200,000 mg/L TDS, 185,000 mg/L TDS to 210,000 mg/L TDS, 190,000 mg/L TDS to 195,000 mg/L TDS, 190,000 mg/L TDS to 200,000 mg/L TDS, 190,000 mg/L TDS to 210,000 mg/L TDS, 195,000 mg/L TDS to 200,000 mg/L TDS, 195,000 mg/L TDS to 210,000 mg/L TDS, or 200,000 mg/L TDS to 210,000 mg/L TDS. In certain embodiments, the reverse concentrate 145 contains 150,000 mg/L TDS, 155,000 mg/L TDS, 160,000 mg/L TDS, 165,000 mg/L TDS, 170,000 mg/L TDS, 175,000 mg/L TDS, 180,000 mg/L TDS, 185,000 mg/L TDS, 190,000 mg/L TDS, 195,000 mg/L TDS, 200,000 mg/L TDS, or 210,000 mg/L TDS. In certain embodiments, the reverse concentrate 145 contains at least 150,000 mg/L TDS, 155,000 mg/L TDS, 160,000 mg/L TDS, 165,000 mg/L TDS, 170,000 mg/L TDS, 175,000 mg/L TDS, 180,000 mg/L TDS, 185,000 mg/L TDS, 190,000 mg/L TDS, 195,000 mg/L TDS, or 200,000 mg/L TDS.

    [0072] In certain embodiments, the aqueous solution 140 is nano filtered using the nanofiltration membrane(s) 112 (in system 100a)/112a (in system 100b)/112a (in system 100c, d) at a pressure of 20 to 60 bar; 25 bar to 50 bar; 25 to 45 bar; or 30 to 40 bar. In certain embodiments, the aqueous solution 140 is nano filtered using the nanofiltration membrane(s) 112 (in system 100a)/112a (in system 100b)/112a (in system 100c, d) at a pressure of 20, 25, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 45, 50, 55 or 60 bar, or any range or value therebetween. In certain embodiments, the first intermediate concentrate 147 is nano filtered using the nanofiltration membrane(s) 112b (in system 100b)/112b (in system 100c, d) at a pressure of 20 to 60 bar; 25 bar to 50 bar; 25 to 45 bar; or 30 to 40 bar. In certain embodiments, the first intermediate concentrate 147 is nano filtered using the nanofiltration membrane(s) 112b (in system 100b)/112b (in system 100c, d) at a pressure of 20, 25, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 45, 50, 55 or 60 bar, or any range or value therebetween.

    [0073] In certain embodiments, the first concentrate 142 is nano filtered using the nanofiltration membrane(s) 122 (in system 100a)/122a (in system 100b)/122a (in system 100c, d) at a pressure of 20 to 60 bar; 25 bar to 50 bar; 25 to 45 bar; or 30 to 40 bar. In certain embodiments, the first concentrate 142 is nano filtered using the nanofiltration membrane(s) 122 (in system 100a)/122a (in system 100b)/122a (in system 100c, d) at a pressure of 20, 25, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 45, 50, 55 or 60 bar, or any range or value therebetween. In certain embodiments, the second intermediate concentrate 148 is nano filtered using the nanofiltration membrane(s) 122b (in system 100b)/122b (in system 100c, d) at a pressure of 20 to 60 bar; 25 bar to 50 bar; 25 to 45 bar; or 30 to 40 bar. In certain embodiments, the second intermediate concentrate 148 is nano filtered using the nanofiltration membrane(s) 122b (in system 100b)/122b (in system 100c, d) at a pressure of 20, 25, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 45, 50, 55 or 60 bar, or any range or value therebetween.

    [0074] The reverse osmosis membrane 132 can be a osmotically assisted reverse osmosis membrane. In certain embodiments, the osmotically assisted reverse osmosis membrane can be a high rejection osmotically assisted reverse osmosis membrane. In certain embodiments, the reverse osmosis membrane 132 can contain a plurality of reverse osmosis membranes, such as a plurality of osmotically assisted reverse osmosis membranes, such as a plurality of high rejection osmotically assisted reverse osmosis membranes. In certain embodiments, reverse osmosis, such as osmotically assisted reverse osmosis of the second concentrate 143 is performed using the membrane 132 (in system 100a-d) at a pressure of 60 to 85 bar; 65 bar to 80 bar; 70 to 80 bar; or 75 to 80 bar. In certain embodiments, reverse osmosis, such as osmotically assisted reverse osmosis of the second concentrate is performed using the membrane 132 (in system 100a-d) at a pressure of 60, 65, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, or 85, bar, or any range or value therebetween.

    [0075] In certain embodiments, the reverse osmosis membrane 132, such as the high rejection osmotically assisted reverse osmosis membrane has a water permeability of 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 2, 2.5 or 3 L/(m.sup.2.Math.h.Math.bar) or any range or value therebetween. In certain embodiments the reverse osmosis membrane 132, such as the high rejection osmotically assisted reverse osmosis membrane has a water permeability of 0.05 to 3 L/(m.sup.2.Math.h.Math.bar); 0.05 to 2.5 L/(m.sup.2.Math.h.Math.bar); 0.05 to 2 L/(m.sup.2.Math.h.Math.bar); 0.05 to 1.5 L/(m.sup.2.Math.h.Math.bar); 0.05 to 1 L/(m.sup.2.Math.h.Math.bar); 0.05 to 0.8 L/(m.sup.2.Math.h.Math.bar); 0.05 to 0.6 L/(m.sup.2.Math.h.Math.bar); 0.1 to 3 L/(m.sup.2.Math.h.Math.bar); 0.1 to 2.5 L/(m.sup.2.Math.h.Math.bar); 0.1 to 2 L/(m.sup.2.Math.h.Math.bar); 0.1 to 1.5 L/(m.sup.2.Math.h.Math.bar); 0.1 to 1 L/(m.sup.2.Math.h.Math.bar); 0.1 to 0.8 L/(m.sup.2.Math.h.Math.bar); 0.1 to 0.6 L/(m.sup.2.Math.h.Math.bar); 0.2 to 3 L/(m.sup.2.Math.h.Math.bar); 0.2 to 2.5 L/(m.sup.2.Math.h.Math.bar); 0.2 to 2 L/(m.sup.2.Math.h.Math.bar); 0.2 to 1.5 L/(m.sup.2.Math.h.Math.bar); 0.2 to 1 L/(m.sup.2.Math.h.Math.bar); 0.2 to 0.8 L/(m.sup.2.Math.h.Math.bar); 0.2 to 0.6 L/(m.sup.2.Math.h.Math.bar); 0.3 to 3 L/(m.sup.2.Math.h.Math.bar); 0.3 to 2.5 L/(m.sup.2.Math.h.Math.bar); 0.3 to 2 L/(m.sup.2.Math.h.Math.bar); 0.3 to 1.5 L/(m.sup.2.Math.h.Math.bar); 0.3 to 1 L/(m.sup.2.Math.h.Math.bar); 0.3 to 0.8 L/(m.sup.2.Math.h.Math.bar); 0.3 to 0.6 L/(m.sup.2.Math.h.Math.bar); 0.4 to 3 L/(m.sup.2.Math.h.Math.bar); 0.4 to 2.5 L/(m.sup.2.Math.h.Math.bar); 0.4 to 2 L/(m.sup.2.Math.h.Math.bar); 0.4 to 1.5 L/(m.sup.2.Math.h.Math.bar); 0.4 to 1 L/(m.sup.2.Math.h.Math.bar); 0.4 to 0.8 L/(m.sup.2.Math.h.Math.bar); 0.4 to 0.6 L/(m.sup.2.Math.h.Math.bar); 0.5 to 3 L/(m.sup.2.Math.h.Math.bar); 0.5 to 2.5 L/(m.sup.2.Math.h.Math.bar); 0.5 to 2 L/(m.sup.2.Math.h.Math.bar); 0.5 to 1.5 L/(m.sup.2.Math.h.Math.bar); 0.5 to 1 L/(m.sup.2.Math.h.Math.bar); 0.5 to 0.8 L/(m.sup.2.Math.h.Math.bar); or 0.5 to 0.6 L/(m.sup.2.Math.h.Math.bar).

    [0076] In certain embodiments, the reverse osmosis membrane 132, such as the high rejection osmotically assisted reverse osmosis membrane has a salt permeability of 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 25 or 30 L/(m.sup.2.Math.h) or any range or value therebetween. In certain embodiments the reverse osmosis membrane 132, such as the high rejection osmotically assisted reverse osmosis membrane has a salt permeability of 0.5 to 30 L/(m.sup.2.Math.h); 0.5 to 25 L/(m.sup.2.Math.h); 0.5 to 20 L/(m.sup.2.Math.h); 0.5 to 15 L/(m.sup.2.Math.h); 0.5 to 12 L/(m.sup.2.Math.h); 0.5 to 10 L/(m.sup.2.Math.h); 1 to 30 L/(m.sup.2.Math.h); 1 to 25 L/(m.sup.2.Math.h); 1 to 20 L/(m.sup.2.Math.h); 1 to 15 L/(m.sup.2.Math.h); 1 to 12 L/(m.sup.2.Math.h); 1 to 10 L/(m.sup.2.Math.h); 3 to 30 L/(m.sup.2.Math.h); 3 to 25 L/(m.sup.2.Math.h); 3 to 20 L/(m.sup.2.Math.h); 3 to 15 L/(m.sup.2.Math.h); 3 to 12 L/(m.sup.2.Math.h); 3 to 10 L/(m.sup.2.Math.h); 3 to 30 L/(m.sup.2.Math.h); 3 to 25 L/(m.sup.2.Math.h); 3 to 20 L/(m.sup.2.Math.h); 3 to 15 L/(m.sup.2.Math.h); 3 to 12 L/(m.sup.2.Math.h); 3 to 10 L/(m.sup.2.Math.h); 5 to 30 L/(m.sup.2.Math.h); 5 to 25 L/(m.sup.2.Math.h); 5 to 20 L/(m.sup.2.Math.h); 5 to 15 L/(m.sup.2.Math.h); 5 to 12 L/(m.sup.2.Math.h); 5 to 10 L/(m.sup.2.Math.h); 7 to 30 L/(m.sup.2.Math.h); 7 to 25 L/(m.sup.2.Math.h); 7 to 20 L/(m.sup.2.Math.h); 7 to 15 L/(m.sup.2.Math.h); 7 to 12 L/(m.sup.2.Math.h); 7 to 10 L/(m.sup.2.Math.h); 9 to 30 L/(m.sup.2.Math.h); 9 to 25 L/(m.sup.2.Math.h); 9 to 20 L/(m.sup.2.Math.h); 9 to 15 L/(m.sup.2.Math.h); 9 to 12 L/(m.sup.2.Math.h); or 9 to 10 L/(m.sup.2.Math.h).

    [0077] Although embodiments of the present application and their advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the embodiments as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the above disclosure, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein can be utilized. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.

    Example

    [0078] A simulation model was developed using a system containing a first nanofiltration unit, a second nanofiltration unit, and a osmotically assisted reverse osmosis unit. The first nanofiltration unit included a plurality of first high rejection nanofiltration membranes and a plurality of first low rejection membranes. The first high rejection nanofiltration membranes had a salt permeability of 3.9 L/(m.sup.2.Math.h) and a water permeability of 0.4 L/(m.sup.2.Math.h.Math.bar). The first low rejection nanofiltration membranes had a salt permeability of 230 L/(m.sup.2.Math.h) and a water permeability of 2.7 L/(m.sup.2.Math.h.Math.bar). The second nanofiltration unit included a plurality of second high rejection nanofiltration membranes and a plurality of second low rejection membranes. The second high rejection nanofiltration membranes had a salt permeability of 3.9 L/(m.sup.2.Math.h) and a water permeability of 0.4 L/(m.sup.2.Math.h.Math.bar). The second low rejection nanofiltration membranes had a salt permeability of 230 L/(m.sup.2.Math.h) and a water permeability of 2.7 L/(m.sup.2.Math.h.Math.bar). The osmotically assisted reverse osmosis unit included a plurality of high rejection osmotically assisted reverse osmosis membranes. The high rejection osmotically assisted reverse osmosis membranes had a salt permeability of 9.2 L/(m.sup.2.Math.h) and a water permeability of 0.57 L/(m.sup.2.Math.h.Math.bar). A brine solution having a concentration of 78,000 mg/L TDS was flowed into the first nanofiltration unit at a flow rate of 10 m.sup.3/h. The brine solution was nanofiltered using the first high rejection and first low rejection nanofiltration membranes at 35 bar to produce a first retentate. The first retentate was further nanofiltered using the second high rejection and second low rejection nanofiltration membranes at 35 bar to produce a second retentate. The second retentate had a concentration of 110,000 mg/L TDS. The second retentate was flowed into the osmotically assisted reverse osmosis unit at a flow rate of 2.7 m.sup.3/h. Osmotically assisted reverse osmosis of the second retentate was performed using the plurality of high rejection osmotically assisted reverse osmosis membranes at 73-75 bar to produce a reverse osmosis retentate having a concentration of 181,000 mg/L TDS. The reverse osmosis retentate had a flow rate of 1 m.sup.3/h.