WO2020251568A1

WO2020251568A1 - Osmotically assisted cascade water desalination systems, concentrators and hybrid systems

Info

Publication number: WO2020251568A1
Application number: PCT/US2019/036797
Authority: WO
Inventors: Basel ABUSHARKH; Emre Erbil
Original assignee: Hyrec Technologies Ltd.
Priority date: 2019-06-12
Filing date: 2019-06-12
Publication date: 2020-12-17

Abstract

Osmotically assisted cascade concentrators (10, 700, 800, 1300) and hybrid osmotically assisted cascade concentrator and desalination systems (200, 300, 500, 600, 900, 1000, 1100, 1200, 4000, 5000) are provided. Each of the osmotically assisted cascade concentrators (10, 1300) and each of the hybrid osmotically assisted cascade concentrator and desalination systems (200, 300, 500, 600, 900, 1000, 1100, 1200, 4000, 5000) uses a concentrator system (700, 800), which includes plurality of filtration stages (720A, 720B, 720C, 720D, 820A, 820B, 820C, 820D, 820E) connected in series, where each filtration stage (720A, 720B, 720C, 720D, 820A, 820B, 820C, 820D, 820E) includes a plurality of reverse osmosis filtration units (722A, 722B, 722C, 722D) connected to each other in parallel.

Description

OSMOTICALLY ASSISTED CASCADE WATER DESALINATION SYSTEMS.

CONCENTRATORS AND HYBRID SYSTEMS

TECHNICAL FIELD

The disclosure of the present patent application relates generally to liquid treatment, and particularly to osmotically assisted cascade water desalination systems, osmotically assisted cascade concentrators, and hybrid osmotically assisted cascade concentrator and water desalination systems.

BACKGROUND ART

As the demand for water constantly grows, the water industry is embracing advanced water treatment processes for the desalination of saline water, such as seawater or brackish water, and reclamation of impaired water, such as wastewater and drainage water. Some processes that have been used to desalinate water are membrane processes, such as reverse osmosis, nanofiltration, electrodialysis, and thermal distillation. Microfiltration and ultrafiltration membrane processes are being increasingly used for surface water and wastewater treatment.

Water recovery is a major economic parameter of drinking water production. However, this parameter is typically limited in existing membrane desalination processes. In addition to limited water recovery, another drawback is that these traditional processes are typically considered energy intensive. Membrane -based systems can suffer from additional problems, such as membrane fouling and scaling in pressure-driven membrane processes (e.g., in reverse osmosis, nanofiltration, ultrafiltration, and microfiltration). These problems are of particular concern, since they can increase the cost of operating and maintaining the systems. Pretreatment of the feed water is a way of reducing fouling and scaling, but is typically expensive. An additional drawback of most membrane-based systems is that increased salt content of the feed stream typically reduces the flux of product water due to the higher osmotic potential difference between the feed solution and the permeate.

Seawater desalination has become a common practice to supply the growing demand for water in areas having access to the ocean. Shortage of potable water in inland areas poses much more complicated challenges to water authorities, governments and other stakeholders. Inland regions are restricted to the use of surface water, groundwater, and/or reclaimed water. Most wastewater treatment plants use combinations of physical, biological, and chemical processes to treat wastewater before discharge to the environment or beneficial reuse. These processes have high operating and maintenance costs, including energy and chemicals. Thus, osmotically assisted cascade water desalination systems, concentrators and hybrid systems solving the aforementioned problems are desired.

DISCLOSURE

An osmotically assisted cascade concentrator includes a forward osmosis filtration unit and a concentration system. The forward osmosis unit has a feed side and a draw side, with the feed side receiving a first salt water feed and producing a concentrated saline stream. The forward osmosis filtration unit produces a dilute draw solution from the draw side. The concentration system receives a second salt water feed and the dilute draw solution. The concentration system produces a stream of concentrated saline and a stream of dilute saline. The stream of concentrated saline is input to the draw side of the forward osmosis filtration unit. The concentration system may be formed from a cascaded plurality of filtration stages connected in series, where each of the filtration stages includes a plurality of reverse osmosis filtration units connected to each other in parallel.

A hybrid osmotically assisted cascade concentrator and water desalination system includes a forward osmosis filtration unit, having a feed side and a draw side, where the feed side receives a first salt water feed and produces a first concentrated saline stream. The forward osmosis filtration unit produces a dilute draw solution from the draw side. A concentration system receives a second salt water feed. The concentration system produces a stream of concentrated saline and a stream of dilute saline. The stream of concentrated saline is input to the draw side of the forward osmosis filtration unit. A reverse osmosis filtration unit receives the stream of dilute saline from the concentration system and outputs purified water and a second concentrated saline stream. The second concentrated saline stream mixes with the first concentrated saline stream to form the second salt water feed. As in the previous embodiment, the concentration system may be formed from a cascaded plurality of filtration stages connected in series, where each of the filtration stages includes a plurality of reverse osmosis filtration units connected to each other in parallel.

An alternative embodiment of the hybrid osmotically assisted cascade concentrator and water desalination system includes a first forward osmosis filtration unit, a concentration system, a second forward osmosis filtration unit, and a reverse osmosis unit. The first forward osmosis filtration unit has a feed side and a draw side, with the feed side receiving a first salt water feed and producing a first concentrated saline stream. The first forward osmosis filtration unit produces a first dilute draw solution from the draw side. The concentration system receives a second salt water feed. The concentration system produces a stream of concentrated saline and a stream of dilute saline. The stream of concentrated saline is input to the draw side of the first forward osmosis filtration unit. The second forward osmosis filtration unit receives the stream of dilute saline from the concentration system and further receives a first portion of a third salt water feed. The second forward osmosis filtration unit outputs a second concentrated saline stream, which is mixed with a second portion of the third salt water feed to form the first salt water feed. The second forward osmosis filtration unit further outputs a second dilute draw solution. A reverse osmosis filtration unit receives the second dilute draw solution from the second forward osmosis filtration unit and outputs purified water and a third concentrated saline stream. The third concentrated saline stream mixes with the first concentrated saline stream to form the second salt water feed. As in the previous embodiments, the concentration system may be formed from a cascaded plurality of filtration stages connected in series, where each of the filtration stages includes a plurality of reverse osmosis filtration units connected to each other in parallel.

Another alternative embodiment of the hybrid osmotically assisted cascade concentrator and water desalination system includes a concentration system, a first reverse osmosis unit and a second reverse osmosis unit. The first reverse osmosis unit receives at least a first portion of a salt water feed and produces a first reject stream and a first purified water stream. The first reject stream mixes with a second portion of the salt water feed to form a first concentrated saline stream. The first concentrated saline stream is fed to the concentration system to produce a second concentrated saline stream and a first dilute saline stream. The second reverse osmosis unit receives a first portion of the first dilute saline stream and produces a second reject stream and a second purified water stream. The second purified water stream is mixed with the first purified water stream to form a purified water output stream. A second portion of the first dilute saline stream mixes with a first portion of the second reject stream to form a dilute solution output stream. A second portion of the second reject stream is split into a third portion of the second reject stream and a fourth portion of the second reject stream. The third portion of the second reject stream is mixed with the first portion of the salt water feed, and the fourth portion of the second reject stream is input to the concentration system.

An energy recovery device may be added to the hybrid osmotically assisted cascade concentrator and water desalination system. The energy recovery device receives a second portion of the salt water feed and the second concentrated saline stream. The energy recovery device may produce a second dilute saline stream and a concentrated saline output stream. The second dilute saline stream mixes with the first portion of the salt water feed received by the first reverse osmosis unit, and generates power from a difference in concentration between the second concentrated saline stream and the second portion of the salt water feed. As non-limiting examples, the energy recovery device may be a reverse electrodialysis (RED) generator, a pressure retarded osmosis (PRO) solvent separator in combination with a turbine, a pressure exchanger for transferring pressure from the concentrated saline stream of the concentration system to the second portion of the salt water, or the like. As in the previous embodiments, the concentration system may be formed from a cascaded plurality of filtration stages connected in series, where each of the filtration stages includes a plurality of reverse osmosis filtration units connected to each other in parallel.

Another alternative embodiment of the hybrid osmotically assisted cascade concentrator and water desalination system includes a concentration system, a first reverse osmosis unit, and a second reverse osmosis unit. The first reverse osmosis unit receives at least a first portion of a salt water feed and produces a first reject stream and a first purified water stream. The first reject stream is fed to the concentration system to produce a first concentrated saline stream and a first dilute saline stream. The second reverse osmosis unit receives the first dilute saline stream and produces a second reject stream and a second purified water stream. The second purified water stream is mixed with the first purified water stream to form a purified water output stream. A first portion of the second reject stream forms a dilute solution output stream, a second portion of the second reject stream is input to the concentration system with the first reject stream, and a third portion of the second reject stream mixes with the first portion of the salt water feed.

Similar to the previous embodiment, an energy recovery device may be added to the hybrid osmotically assisted cascade concentrator and water desalination system. The energy recovery device receives a second portion of the salt water feed and the first concentrated saline stream. The energy recovery device may produce a second dilute saline stream and a concentrated saline output stream. The second dilute saline stream mixes with the first portion of the salt water feed received by the first reverse osmosis unit, and generates power from a difference in concentration between the first concentrated saline stream and the second portion of the salt water feed. As non-limiting examples, the energy recovery device may be a reverse electrodialysis (RED) generator, a pressure retarded osmosis (PRO) solvent separator in combination with a turbine, a pressure exchanger for transferring pressure from the concentrated saline stream of the concentration system to the second portion of the salt water, or the like. As in the previous embodiments, the concentration system may be formed from a cascaded plurality of filtration stages connected in series, where each of the filtration stages includes a plurality of reverse osmosis filtration units connected to each other in parallel.

Another alternative embodiment of the hybrid osmotically assisted cascade concentrator and water desalination system includes a concentration system and a reverse osmosis unit. The concentration system receives at least a first portion of a salt water feed and outputs a first concentrated saline stream and a first dilute saline stream. The reverse osmosis unit receives the first dilute saline stream and produces a purified water output stream and a reject stream. The reject stream mixes with the first portion of the salt water feed.

Similar to the previous embodiments, an energy recovery device may be added to the hybrid osmotically assisted cascade concentrator and water desalination system for receiving a second portion of the salt water feed and the first concentrated saline stream. The energy recovery device may produce a second dilute saline stream and a concentrated saline output stream. The second dilute saline stream mixes with the first portion of the salt water feed, and the energy recovery device generates power from a difference in concentration between the first concentrated saline stream and the second portion of the salt water feed. As non limiting examples, the energy recovery device may be a reverse electrodialysis (RED) generator, a pressure retarded osmosis (PRO) solvent separator in combination with a turbine, a pressure exchanger for transferring pressure from the concentrated saline stream of the concentration system to the second portion of the salt water, or the like. As in the previous embodiments, the concentration system may be formed from a cascaded plurality of filtration stages connected in series, where each of the filtration stages includes a plurality of reverse osmosis filtration units connected to each other in parallel.

Another alternative embodiment of the hybrid osmotically assisted cascade concentrator and water desalination system includes a reverse osmosis unit and a concentration system. The reverse osmosis unit receives at least a first portion of a salt water feed and outputs a reject stream and a purified water output stream. The concentration system receives the reject stream and produces a first concentrated saline stream and a first dilute saline stream. A first portion of the first dilute saline stream mixes with the first portion of the salt water feed, and a second portion of the first dilute saline stream forms a dilute saline output stream. Similar to the previous embodiments, an energy recovery device may be added to the hybrid osmotically assisted cascade concentrator and water desalination system for receiving a second portion of the salt water feed and the first concentrated saline stream. The energy recovery device may produce a second dilute saline stream and a concentrated saline output stream. The second dilute saline stream mixes with the first portion of the salt water feed, and the energy recovery device generates power from a difference in concentration between the first concentrated saline stream and the second portion of the salt water feed. As non-limiting examples, the energy recovery device may be a reverse electrodialysis (RED) generator, a pressure retarded osmosis (PRO) solvent separator in combination with a turbine, a pressure exchanger for transferring pressure from the concentrated saline stream of the concentration system to the second portion of the salt water, or the like. As in the previous embodiments, the concentration system may be formed from a cascaded plurality of filtration stages connected in series, where each of the filtration stages includes a plurality of reverse osmosis filtration units connected to each other in parallel.

Another embodiment of the hybrid osmotically assisted cascade concentrator and water desalination system includes a concentration system and a reverse osmosis unit. The concentration system receives at least a first portion of a salt water feed and outputs a first concentrated saline stream and a first dilute saline stream. The reverse osmosis unit receives the first dilute saline stream and produces a reject stream and a purified water output stream. A first portion of the reject stream mixes with the first portion of the salt water feed, a second portion of the reject stream forms a dilute saline output stream, and a third portion of the reject stream is input to the concentration system. Similar to the previous embodiments, an energy recovery device may be added to the hybrid osmotically assisted cascade concentrator and water desalination system for receiving a second portion of the salt water feed and the first concentrated saline stream. The energy recovery device may produce a second dilute saline stream and a concentrated saline output stream. The second dilute saline stream mixes with the first portion of the salt water feed, and the energy recovery device generates power from a difference in concentration between the first concentrated saline stream and the second portion of the salt water feed. As non-limiting examples, the energy recovery device may be a reverse electrodialysis (RED) generator, a pressure retarded osmosis (PRO) solvent separator in combination with a turbine, a pressure exchanger for transferring pressure from the concentrated saline stream of the concentration system to the second portion of the salt water, or the like. As in the previous embodiments, the concentration system may be formed from a cascaded plurality of filtration stages connected in series, where each of the filtration stages includes a plurality of reverse osmosis filtration units connected to each other in parallel.

Another alternative embodiment of the hybrid osmotically assisted cascade concentrator and water desalination system includes a reverse osmosis unit and a concentration system. The reverse osmosis unit receives at least a first portion of a salt water feed and outputs a reject stream and a purified water output stream. The concentration system receives the reject stream and produces a first concentrated saline stream and a first dilute saline stream. A first portion of the first dilute saline stream mixes with the first portion of the salt water feed, a second portion of the first dilute saline stream forms a dilute saline output stream, and a third portion of the first dilute saline stream is input to the concentration system.

An osmotically assisted cascade concentrator includes a concentration system for receiving at least a first portion of a salt water feed and outputting a first concentrated saline stream and a first dilute saline stream. A first portion of the dilute saline stream forms a dilute saline output stream, and a second portion of the dilute saline stream is mixed with the first portion of the salt water feed. Similar to the previous embodiments, an energy recovery device may be added to the osmotically assisted cascade concentrator for receiving a second portion of the salt water feed and the first concentrated saline stream. The energy recovery device may produce a second dilute saline stream and a concentrated saline output stream. The second dilute saline stream mixes with the first portion of the salt water feed, and the energy recovery device generates power from a difference in concentration between the first concentrated saline stream and the second portion of the salt water feed. As non-limiting examples, the energy recovery device may be a reverse electrodialysis (RED) generator, a pressure retarded osmosis (PRO) solvent separator in combination with a turbine, a pressure exchanger for transferring pressure from the concentrated saline stream of the concentration system to the second portion of the salt water, or the like. As in the previous embodiments, the concentration system may be formed from a cascaded plurality of filtration stages connected in series, where each of the filtration stages includes a plurality of reverse osmosis filtration units connected to each other in parallel.

A further alternative hybrid osmotically assisted cascade concentrator and water desalination system includes a plurality of concentration systems in fluid communication with each other, a plurality of tanks, and a reverse osmosis filtration unit. A first one of the plurality of concentration systems receives a first salt water feed from a first one of the tanks and produces a first concentrated saline stream and a first dilute saline stream. The first one of the tanks receives the first concentrated saline stream, and the first dilute saline stream is received by a subsequent one of the plurality of tanks. The first one of the plurality of concentration systems further receives a subsequent concentrated saline stream produced by a subsequent one of the plurality of concentration systems.

A final one of the plurality of concentration systems receives a final salt water feed from a preceding one of the tanks and produces a final concentrated saline stream and a final dilute saline stream. A final one of the tanks receives the final dilute saline stream, and the final concentrated saline stream is received by a preceding one of the plurality of concentration systems. The reverse osmosis filtration unit receives a secondary dilute saline stream from the final one of the tanks and produces a secondary concentrated saline stream and a purified water stream. The final one of the plurality of concentration systems receives the secondary concentrated saline stream. As in the previous embodiments, each concentration system may be formed from a cascaded plurality of filtration stages connected in series, where each of the filtration stages includes a plurality of reverse osmosis filtration units connected to each other in parallel.

Another alternative hybrid osmotically assisted cascade concentrator and water desalination system includes a plurality of concentration systems in fluid communication with each other, a plurality of tanks, a plurality of energy recovery devices, and a reverse osmosis filtration unit. A first one of the plurality of concentration systems receives a first salt water feed from a first one of the plurality of tanks and produces a first concentrated saline stream and a first dilute saline stream. A subsequent one of the plurality of tanks receives the first dilute saline stream, and a first one of the plurality of energy recovery devices receives the first dilute saline stream from the subsequent one of the plurality of tanks, and further receives the first concentrated saline stream. The first one of the plurality of energy recovery devices feeds the first salt water feed to the first one of the plurality of tanks, and further feeds a subsequent salt water feed to a subsequent one of the plurality of concentration systems.

A final one of the plurality of concentration systems receives a final salt water feed from a preceding one of the plurality of energy recovery devices and produces a final concentrated saline stream and a final dilute saline stream. A final one of the tanks receives the final dilute saline stream, and the final concentrated saline stream is received by a final one of the energy recovery devices. The final one of the energy recovery devices receives a secondary salt water feed from the final one of the plurality of tanks, and the final one of the energy recovery devices produces a secondary salt water feed and a secondary concentrated saline stream. The secondary concentrated saline stream is received by a preceding one of the plurality of concentration systems.

The reverse osmosis filtration unit receives a secondary salt water feed from the final one of the energy recovery devices and produces a tertiary concentrated saline stream and a purified water stream. The final one of the plurality of concentration systems receives the tertiary concentrated saline stream. As in the previous embodiments, each concentration system may be formed from a cascaded plurality of filtration stages connected in series, where each of the filtration stages includes a plurality of reverse osmosis filtration units connected to each other in parallel. Further, as in the previous embodiments, each energy recovery device may be a reverse electrodialysis generator, a pressure retarded osmosis solvent separator in combination with a turbine, a pressure exchanger or the like.

These and other features of the present disclosure will become readily apparent upon further review of the following specification and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a schematic diagram of an osmotically assisted cascade concentrator.

Fig. 2 is a schematic diagram of a hybrid osmotically assisted cascade concentrator and water desalination system. Fig. 3 is a schematic diagram of an alternative embodiment of the hybrid osmotically assisted cascade concentrator and water desalination system.

Fig. 4A is a schematic diagram of a concentration system.

Fig. 4B is a schematic diagram of an individual concentration stage of the concentration system of Fig. 4A.

Fig. 5 is a schematic diagram of an alternative embodiment of the concentration system.

Fig. 6 is a schematic diagram of another alternative embodiment of the hybrid osmotically assisted cascade concentrator and water desalination system.

Fig. 7 is a schematic diagram of another alternative embodiment of the hybrid osmotically assisted cascade concentrator and water desalination system.

Fig. 8 is a schematic diagram of another alternative embodiment of the hybrid osmotically assisted cascade concentrator and water desalination system.

Fig. 9 is a schematic diagram of another alternative embodiment of the hybrid osmotically assisted cascade concentrator and water desalination system.

Fig. 10 is a schematic diagram of an osmotically assisted cascade concentrator.

Fig. 11 is a schematic diagram of another alternative embodiment of the hybrid osmotically assisted cascade concentrator and water desalination system.

Fig. 12 is a schematic diagram of another alternative embodiment of the hybrid osmotically assisted cascade concentrator and water desalination system.

Fig. 13 is a schematic diagram of still another alternative embodiment of the hybrid osmotically assisted cascade concentrator and water desalination system.

Fig. 14 is a schematic diagram of yet another alternative embodiment of the hybrid osmotically assisted cascade concentrator and water desalination system.

Similar reference characters denote corresponding features consistently throughout the attached drawings.

BEST MODE(S) FOR CARRYING OUT THE INVENTION

As shown in Fig. 1, an osmotically assisted cascade concentrator 10 includes a forward osmosis filtration unit 14 and a concentration system 700. The forward osmosis unit 14 has a feed side and a draw side, with the feed side receiving a first salt water feed FI and producing a concentrated saline stream C3. The forward osmosis filtration unit 14 produces a dilute draw solution Cl from the draw side. The concentration system 700 receives a second salt water feed F2 and the dilute draw solution Cl. The concentration system 700 produces a stream of concentrated saline C2 and a stream of dilute saline D. The stream of concentrated saline C2 is input to the draw side of the forward osmosis filtration unit 14. Additionally, a node 12 may be provided to measure and/or control the flow parameters, such as pressure, flow rate, temperature, density, PH, electrical conductivity, etc. It should be understood that any suitable number of nodes may be utilized and that such nodes may be placed in any desired location in the flow path.

Further, it should be understood that any suitable type of concentration system may be used. As shown in Fig. 4A, the concentration system 700 may include a cascaded plurality of filtration stages 720A, 720B, 720C, 720D connected in series. It should be understood that any suitable number of filtration stages may be used, and that the four filtration stages in Fig. 4A are shown for exemplary purposes only. Each of the filtration stages 720A, 720B, 720C, 720D is identical and operates in an identical manner.

As shown in Fig. 4B, each of the filtration stages 720A, 720B, 720C, 720D (shown only as filtration stage 720A for purposes of simplification) includes a plurality of reverse osmosis filtration units 722 A, 722B, 722C, 722D connected to each other in parallel. It should be understood that any suitable number of reverse osmosis filtration units may be used, and that the four reverse osmosis filtration units in Fig. 4B are shown for exemplary purposes only. Each of the nodes 724, 726, 728, 730, 732, 734, 736, 738 in front of each filter or membrane entrance location measures and/or controls the flow parameters, such as pressure, flow rate, temperature, density, PH, electrical conductivity, etc. It should be understood that nodes 724, 726, 728, 730, 732, 734, 736, 738 may be removed or may be placed in alternative locations. Returning to Fig. 4A, a similar node 740 may be included in the concentration system 700, as well as a plurality of booster pumps 702, 704, 706, 708, 710, 712, 714, 716. It should be understood that any suitable number of nodes may be utilized and that such nodes may be placed in any desired location in the flow path. Similarly, it should be understood that any suitable number and type of pumps may be used, and that the pumps may also be placed in any desired location in the flow path.

For example, the alternative concentration system 800 of Fig. 5 uses a similar arrangement of a cascaded plurality of filtration stages 820A, 820B, 820C, 820D, 820E connected in series, but with the addition of a bypass channel for mixing of bypass fluid BP with the feed stream F. As shown in Fig. 5, in order to mix the bypass fluid BP with the feed stream F, additional pumps 824, 826, 828, 830, 832 are used. These pumps are used in combination with pumps 802, 804, 806, 808, 810, 812, 814, 816, 818, 822, which operate in a manner similar to their counterparts in the previous embodiment. Additionally, similar to the previous embodiment, nodes 834, 836, 838, 840, 842, 844 are provided to measure and/or control the flow parameters, such as pressure, flow rate, temperature, density, PH, electrical conductivity, etc. As in the previous embodiment, it should be understood that any suitable number of nodes may be utilized and that such nodes may be placed in any desired location in the flow path. Similarly, it should be understood that any suitable number and type of pumps may be used, and that the pumps may also be placed in any desired location in the flow path.

Fig. 2 illustrates a hybrid osmotically assisted cascade concentrator and water desalination system 500, which includes a forward osmosis filtration unit 506, having a feed side and a draw side, where the feed side receives a first salt water feed FI and produces a first concentrated saline stream C4. The forward osmosis filtration unit 506 produces a dilute draw solution Cl from the draw side. A concentration system 700 receives a second salt water feed F2. The concentration system 700 produces a stream of concentrated saline C2 and a stream of dilute saline D. The stream of concentrated saline C2 is input to the draw side of the forward osmosis filtration unit 506. A reverse osmosis filtration unit 508 receives the stream of dilute saline D from the concentration system and outputs purified water PW and a second concentrated saline stream C3. The second concentrated saline stream C3 mixes with the dilute draw solution Cl to form the second salt water feed F2. As in the previous embodiment, the concentration system may be any suitable type of concentration system, such as concentration system 700 of Fig. 4A or concentration system 800 of Fig. 5. Additionally, a node 502 may be provided to measure and/or control the flow parameters, such as pressure, flow rate, temperature, density, PH, electrical conductivity, etc. It should be understood that any suitable number of nodes may be utilized and that such nodes may be placed in any desired location in the flow path. Additionally, a pump 504 may be provided for powered fluid circulation. It should be understood that any suitable number and type of pumps may be used, and that the pumps may also be placed in any desired location in the flow path.

Fig. 3 illustrates an alternative embodiment of the hybrid osmotically assisted cascade concentrator and water desalination system 600, which includes a first forward osmosis filtration unit 608, a concentration system 700, and a second forward osmosis filtration unit 612. The first forward osmosis filtration unit 608 has a feed side and a draw side, with the feed side receiving a first salt water feed F3 and producing a first concentrated saline stream C5. The first forward osmosis filtration unit 608 produces a first dilute draw solution Cl from the draw side. The concentration system 700 receives a second salt water feed F2. The concentration system 700 produces a stream of concentrated saline C2 and a stream of dilute saline D. The stream of concentrated saline C2 is input to the draw side of the first forward osmosis filtration unit 608. The second forward osmosis filtration unit 612 receives the stream of dilute saline D from the concentration system 700 and further receives a first portion F4 of a third salt water feed FI. The second forward osmosis filtration unit 612 outputs a second concentrated saline stream C4, which is mixed with a second portion of the third salt water feed FI to form the first salt water feed F3. The second forward osmosis filtration unit 612 further outputs a second dilute draw solution D2. A reverse osmosis filtration unit 610 receives the second dilute draw solution D2 from the second forward osmosis filtration unit 612 and outputs purified water PW and a third concentrated saline stream C3. The third concentrated saline stream C3 mixes with the first concentrated saline stream Cl to form the second salt water feed F2. As in the previous embodiments, the concentration system may be any suitable type of concentration system, such as concentration system 700 of Fig. 4A or concentration system 800 of Fig. 5. Additionally, nodes 602, 604 may be provided to measure and/or control the flow parameters, such as pressure, flow rate, temperature, density, PH, electrical conductivity, etc. It should be understood that any suitable number of nodes may be utilized and that such nodes may be placed in any desired location in the flow path.

Fig. 6 shows another alternative embodiment of the hybrid osmotically assisted cascade concentrator and water desalination system 900, which includes a concentration system 700, a first reverse osmosis unit 930 and a second reverse osmosis unit 940. The first reverse osmosis unit 930 receives at least a first portion FI of a salt water feed F and produces a first reject stream R1 and a first purified water stream PW1. The first reject stream R1 mixes with a second portion of the salt water feed F to form a first concentrated saline stream Cl. The first concentrated saline stream Cl is fed to the concentration system 700 to produce a second concentrated saline stream C2 and a first dilute saline stream Dl. The second reverse osmosis unit 940 receives a first portion of the first dilute saline stream Dl and produces a second reject stream R2 and a second purified water stream PW2. The second purified water stream PW2 is mixed with the first purified water stream PW1 to form a purified water output stream PW. A second portion of the first dilute saline stream Dl mixes with a first portion of the second reject stream R2 to form a dilute solution output stream D2. A second portion of the second reject stream R2 is split into a third portion of the second reject stream R2 and a fourth portion of the second reject stream R2. The third portion of the second reject stream R2 is mixed with the first portion of the salt water feed FI, and the fourth portion of the second reject stream R2 is input to the concentration system 700.

An energy recovery device 2000 may be added to the hybrid osmotically assisted cascade concentrator and water desalination system 900. The energy recovery device 2000 receives a second portion of the salt water feed F2 and the second concentrated saline stream C2. The energy recovery device 2000 produces a second dilute saline stream D4 and a concentrated saline output stream C. The second dilute saline stream D4 mixes with the first portion of the salt water feed FI received by the first reverse osmosis unit 930, and generates power from a difference in concentration between the second concentrated saline stream C2 and the second portion of the salt water feed F2. The energy recovery device 2000 may be a reverse electrodialysis (RED) generator or may include a pressure retarded osmosis (PRO) solvent separator and a turbine. Additionally, similar to the previous embodiments, nodes 902, 904, 906, 908, 910, 912, 914, 916 are provided to measure and/or control the flow parameters, such as pressure, flow rate, temperature, density, PH, electrical conductivity, etc. As in the previous embodiments, it should be understood that any suitable number of nodes may be utilized and that such nodes may be placed in any desired location in the flow path. Similarly, it should be understood that any suitable number and type of pumps, such as pumps 920, 922, 924, may be used, and that the pumps may also be placed in any desired location in the flow path. Additionally, as in the previous embodiments, the concentration system may be any suitable type of concentration system, such as concentration system 700 of Fig. 4A or concentration system 800 of Fig. 5.

The energy recovery device 2000 may alternatively be a pressure exchanger. In this alternative embodiment, the energy recovery device 2000 receives a second portion of the low-pressure salt water feed F2 and the second concentrated high-pressure saline stream C2. The energy recovery device 2000 produces high-pressure feed stream D4 and a low-pressure concentrated saline output stream C. The salt water feed F2, the second concentrated saline stream C2, the feed stream D4 and the saline output stream C can be mixed with each other in the energy recovery device 2000 in any portion and in any combinations or, alternatively, the salt water feed F2, the second concentrated saline stream C2, the feed stream D4 and the saline output stream C are not mixed with each other.

Fig. 7 illustrates another alternative embodiment of the hybrid osmotically assisted cascade concentrator and water desalination system 1000, which includes a concentration system 700, a first reverse osmosis unit 1010, and a second reverse osmosis unit 1020. The first reverse osmosis unit 1010 receives at least a first portion FI of a salt water feed F and produces a first reject stream R1 and a first purified water stream PW1. The first reject stream R1 is fed to the concentration system 700 to produce a first concentrated saline stream C2 and a first dilute saline stream Dl. The second reverse osmosis unit 1020 receives the first dilute saline stream Dl and produces a second reject stream R2 and a second purified water stream PW2. The second purified water stream PW2 is mixed with the first purified water stream PW 1 to form a purified water output stream PW. A first portion of the second reject stream R2 forms a dilute solution output stream D2, a second portion of the second reject stream R2 is input to the concentration system 700 with the first reject stream, and a third portion of the second reject stream R2 mixes with the first portion of the salt water feed FI.

Similar to the previous embodiment, an energy recovery device 2000 may be added to the hybrid osmotically assisted cascade concentrator and water desalination system 1000. The energy recovery device 2000 receives a second portion of the salt water feed F2 and the first concentrated saline stream C2. The energy recovery device 2000 produces a second dilute saline stream D4 and a concentrated saline output stream C. The second dilute saline stream D4 mixes with the first portion of the salt water feed FI received by the first reverse osmosis unit 1010, and generates power from a difference in concentration between the first concentrated saline stream C2 and the second portion of the salt water feed F2. As non limiting examples, the energy recovery device 2000 may be a reverse electrodialysis (RED) generator or may include a pressure retarded osmosis (PRO) solvent separator and a turbine. Additionally, similar to the previous embodiments, nodes 1002, 1004 are provided to measure and/or control the flow parameters, such as pressure, flow rate, temperature, density, PH, electrical conductivity, etc. As in the previous embodiments, it should be understood that any suitable number of nodes may be utilized and that such nodes may be placed in any desired location in the flow path. Similarly, it should be understood that any suitable number and type of pumps, such as pumps 1005, 1006, 1008, may be used, and that the pumps may also be placed in any desired location in the flow path. Additionally, as in the previous embodiments, the concentration system may be any suitable type of concentration system, such as concentration system 700 of Fig. 4A or concentration system 800 of Fig. 5.

Alternatively, the energy recovery device 2000 may be a pressure exchanger. The energy recovery device 2000 receives a second portion of the low-pressure salt water feed F2 and the second concentrated high-pressure saline stream C2. The energy recovery device 2000 produces high-pressure feed stream D4 and a low-pressure concentrated saline output stream C. The salt water feed F2, the second concentrated saline stream C2, the feed stream D4 and the saline output stream C can be mixed with each other in the energy recovery device 2000 in any portion and in any combinations or, alternatively, the salt water feed F2, the second concentrated saline stream C2, the feed stream D4 and the saline output stream C are not mixed with each other.

Fig. 8 illustrates another alternative embodiment of the hybrid osmotically assisted cascade concentrator and water desalination system 1100, including a concentration system 700 and a reverse osmosis unit 1112. The concentration system 700 receives at least a first portion FI of a salt water feed F and outputs a first concentrated saline stream Cl and a first dilute saline stream Dl. The reverse osmosis unit 1112 receives the first dilute saline stream D1 and produces a purified water output stream PW and a reject stream R. The reject stream R mixes with the first portion of the salt water feed FI.

Similar to the previous embodiments, an energy recovery device 2000 may be added to the hybrid osmotically assisted cascade concentrator and water desalination system 1100 for receiving a second portion F2 of the salt water feed F and the first concentrated saline stream Cl. The energy recovery device 2000 produces a second dilute saline stream D2 and a concentrated saline output stream C. The second dilute saline stream D2 mixes with the first portion of the salt water feed FI, and the energy recovery device 2000 generates power from a difference in concentration between the first concentrated saline stream Cl and the second portion of the salt water feed F2. The energy recovery device 2000 may be a reverse electrodialysis (RED) generator or may include a pressure retarded osmosis (PRO) solvent separator and a turbine. Additionally, similar to the previous embodiments, node 1102 is provided to measure and/or control the flow parameters, such as pressure, flow rate, temperature, density, PH, electrical conductivity, etc. As in the previous embodiments, it should be understood that any suitable number of nodes may be utilized and that such nodes may be placed in any desired location in the flow path. Similarly, it should be understood that any suitable number and type of pumps, such as pumps 1104, 1006, 1108, may be used, and that the pumps may also be placed in any desired location in the flow path. Additionally, as in the previous embodiments, the concentration system may be any suitable type of concentration system, such as concentration system 700 of Fig. 4A or concentration system 800 of Fig. 5.

Alternatively, the energy recovery device 2000 may be a pressure exchanger. The energy recovery device 2000 receives a second portion of the low-pressure salt water feed F2 and the second concentrated high-pressure saline stream Cl. The energy recovery device 2000 produces high-pressure feed stream D2 and a low-pressure concentrated saline output stream C. The salt water feed F2, the second concentrated saline stream Cl, the feed stream D2 and the saline output stream C can be mixed with each other in the energy recovery device 2000 in any portion and in any combinations or, alternatively, the salt water feed F2, the second concentrated saline stream Cl, the feed stream D2 and the saline output stream C are not mixed with each other.

Fig. 9 shows another alternative embodiment of the hybrid osmotically assisted cascade concentrator and water desalination system 1200, which includes a reverse osmosis unit 1202 and a concentration system 700. The reverse osmosis unit 1202 receives at least a first portion FI of a salt water feed F and outputs a reject stream R and a purified water output stream PW. The concentration system 700 receives the reject stream R and produces a first concentrated saline stream C2 and a first dilute saline stream. A first portion of the first dilute saline stream mixes with the first portion of the salt water feed FI, and a second portion of the first dilute saline stream forms a dilute saline output stream D. Similar to the previous embodiments, an energy recovery device 2000 may be added to the hybrid osmotically assisted cascade concentrator and water desalination system 1200 for receiving a second portion F2 of the salt water feed F and the first concentrated saline stream C2. The energy recovery device 2000 produces a second dilute saline stream D1 and a concentrated saline output stream C. The second dilute saline stream D1 mixes with the first portion of the salt water feed FI, and the energy recovery device 2000 generates power from a difference in concentration between the first concentrated saline stream C2 and the second portion of the salt water feed F2. The energy recovery device 2000 may be a reverse electrodialysis (RED) generator or may include a pressure retarded osmosis (PRO) solvent separator and a turbine. Additionally, similar to the previous embodiments, nodes 1204, 1208 are provided to measure and/or control the flow parameters, such as pressure, flow rate, temperature, density, PH, electrical conductivity, etc. As in the previous embodiments, it should be understood that any suitable number of nodes may be utilized and that such nodes may be placed in any desired location in the flow path. Similarly, it should be understood that any suitable number and type of pumps, such as pumps 1206, 1210, 1212, may be used, and that the pumps may also be placed in any desired location in the flow path. Additionally, as in the previous embodiments, the concentration system may be any suitable type of concentration system, such as concentration system 700 of Fig. 4A or concentration system 800 of Fig. 5.

Alternatively, the energy recovery device 2000 may be a pressure exchanger. The energy recovery device 2000 receives a second portion of the low-pressure salt water feed F2 and the second concentrated high-pressure saline stream C2. The energy recovery device 2000 produces high-pressure feed stream D1 and a low-pressure concentrated saline output stream C. The salt water feed F2, the second concentrated saline stream C2, the feed stream D1 and the saline output stream C can be mixed with each other in the energy recovery device 2000 in any portion and in any combinations or, alternatively, the salt water feed F2, the second concentrated saline stream C2, the feed stream D1 and the saline output stream C are not mixed with each other.

In the alternative embodiment of Fig. 11, the hybrid osmotically assisted cascade concentrator and water desalination system 200 includes a concentration system 800 and a reverse osmosis unit 220. The concentration system 800 receives at least a first portion FI of a salt water feed F and outputs a first concentrated saline stream Cl and a first dilute saline stream Dl. The reverse osmosis unit 220 receives the first dilute saline stream D1 and produces a reject stream R and a purified water output stream PW. A first portion D4 of the reject stream R mixes with the first portion of the salt water feed FI, a second portion of the reject stream R forms a dilute saline output stream D2, and a third portion D3 of the reject stream R is input to the concentration system 800. Similar to the previous embodiments, an energy recovery device 2000 may be added to the hybrid osmotically assisted cascade concentrator and water desalination system 200 for receiving a second portion of the salt water feed F2 and the first concentrated saline stream Cl. The energy recovery device 2000 produces a second dilute saline stream D5 and a concentrated saline output stream C. The second dilute saline stream D5 mixes with the first portion of the salt water feed FI, and the energy recovery device 2000 generates power from a difference in concentration between the first concentrated saline stream Cl and the second portion of the salt water feed F2. The energy recovery device 2000 may be a reverse electrodialysis (RED) generator or may include a pressure retarded osmosis (PRO) solvent separator and a turbine. Additionally, similar to the previous embodiments, nodes 202, 204 are provided to measure and/or control the flow parameters, such as pressure, flow rate, temperature, density, PH, electrical conductivity, etc. As in the previous embodiments, it should be understood that any suitable number of nodes may be utilized and that such nodes may be placed in any desired location in the flow path. Similarly, it should be understood that any suitable number and type of pumps, such as pumps 206, 208, 212, may be used, and that the pumps may also be placed in any desired location in the flow path. Additionally, as in the previous embodiments, the concentration system may be any suitable type of concentration system, such as concentration system 700 of Fig. 4A or concentration system 800 of Fig. 5. Alternatively, the energy recovery device 2000 may be a pressure exchanger. The energy recovery device 2000 receives a second portion of the low-pressure salt water feed F2 and the second concentrated high-pressure saline stream Cl. The energy recovery device 2000 produces high-pressure feed stream D5 and a low-pressure concentrated saline output stream C. The salt water feed F2, the second concentrated saline stream Cl, the feed stream D5 and the saline output stream C can be mixed with each other in the energy recovery device 2000 in any portion and in any combinations or, alternatively, the salt water feed F2, the second concentrated saline stream Cl, the feed stream D5 and the saline output stream C are not mixed with each other.

Fig. 12 illustrates another alternative embodiment of the hybrid osmotically assisted cascade concentrator and water desalination system 300, which includes a reverse osmosis unit 302 and a concentration system 800. The reverse osmosis unit 302 receives at least a first portion FI of a salt water feed F and outputs a reject stream R and a purified water output stream PW. The concentration system 800 receives the reject stream R and produces a first concentrated saline stream C2 and a first dilute saline stream Dl. A first portion of the first dilute saline D3 stream mixes with the first portion of the salt water feed FI, a second portion of the first dilute saline stream Dl forms a dilute saline output stream D, and a third portion D2 of the first dilute saline stream Dl is input to the concentration system 800.

Similar to the previous embodiments, an energy recovery device 2000 may be added to the hybrid osmotically assisted cascade concentrator and water desalination system 300 for receiving a second portion F2 of the salt water feed F and the first concentrated saline stream C2. The energy recovery device 2000 produces a second dilute saline stream D4 and a concentrated saline output stream C. The second dilute saline stream D4 mixes with the first portion of the salt water feed FI, and the energy recovery device 2000 generates power from a difference in concentration between the first concentrated saline stream C2 and the second portion of the salt water feed F2. The energy recovery device 2000 may be a reverse electrodialysis (RED) generator or may include a pressure retarded osmosis (PRO) solvent separator and a turbine. Additionally, similar to the previous embodiments, nodes 304, 308 are provided to measure and/or control the flow parameters, such as pressure, flow rate, temperature, density, PH, electrical conductivity, etc. As in the previous embodiments, it should be understood that any suitable number of nodes may be utilized and that such nodes may be placed in any desired location in the flow path. Similarly, it should be understood that any suitable number and type of pumps, such as pumps 306, 312, may be used, and that the pumps may also be placed in any desired location in the flow path. Additionally, as in the previous embodiments, the concentration system may be any suitable type of concentration system, such as concentration system 700 of Fig. 4A or concentration system 800 of Fig. 5.

Fig. 10 shows an osmotically assisted cascade concentrator 1300, which includes a concentration system 700 for receiving at least a first portion FI of a salt water feed F and outputting a first concentrated saline stream Cl and a first dilute saline stream D2. A first portion of the first dilute saline stream D2 forms a dilute saline output stream D, and a second portion of the first dilute saline stream D2 is mixed with the first portion of the salt water feed FI. Similar to the previous embodiments, an energy recovery device 2000 may be added to the osmotically assisted cascade concentrator 1300 for receiving a second portion of the salt water feed F2 and the first concentrated saline stream Cl. The energy recovery device 2000 produces a second dilute saline stream D1 and a concentrated saline output stream C. The second dilute saline stream D1 mixes with the first portion of the salt water feed FI, and the energy recovery device 2000 generates power from a difference in concentration between the first concentrated saline stream Cl and the second portion of the salt water feed F2. The energy recovery device 2000 may be a reverse electrodialysis (RED) generator or may include a pressure retarded osmosis (PRO) solvent separator and a turbine. Additionally, similar to the previous embodiments, nodes 1302, 1304 are provided to measure and/or control the flow parameters, such as pressure, flow rate, temperature, density, PH, electrical conductivity, etc. As in the previous embodiments, it should be understood that any suitable number of nodes may be utilized and that such nodes may be placed in any desired location in the flow path. Similarly, it should be understood that any suitable number and type of pumps, such as pumps 1306, 1308, may be used, and that the pumps may also be placed in any desired location in the flow path. Additionally, as in the previous embodiments, the concentration system may be any suitable type of concentration system, such as concentration system 700 of Fig. 4A or concentration system 800 of Fig. 5. Alternatively, the energy recovery device 2000 may be a pressure exchanger. The energy recovery device 2000 receives a second portion of the low-pressure salt water feed F2 and the second concentrated high-pressure saline stream Cl. The energy recovery device 2000 produces high-pressure feed stream D1 and a low-pressure concentrated saline output stream C. The salt water feed F2, the second concentrated saline stream Cl, the feed stream D1 and the saline output stream C can be mixed with each other in the energy recovery device 2000 in any portion and in any combinations or, alternatively, the salt water feed F2, the second concentrated saline stream Cl, the feed stream D1 and the saline output stream C are not mixed with each other. It should be understood that hybrid osmotically assisted cascade concentrator and water desalination systems 200, 300, 900, 1000, 1100, and 1200 may also be used as stand-alone concentrators.

Fig. 13 shows an alternative hybrid osmotically assisted cascade concentrator and water desalination system 4000 that includes a plurality of concentration systems. Although only three such concentration systems 4000A, 4000B, 4000C are shown, it should be understood that this is for purposes of simplification only, and for purposes of the below discussion, any suitable number n concentration systems may be connected to one another. Each of the three concentration systems 4000 A, 4000B, 4000C has a corresponding tank 4100A, 4100B, 4100C, respectively, although it should be understood that n such tanks may be provided, along with one additional tank (i.e., tank 4100D, as will be explained in greater detail below). In the following description of Fig. 13, concentrated saline streams are designated by the suffix“-C”, while dilute saline streams are distinguished by the suffix“- D”, except where explicitly designated otherwise.

As shown, the first concentration system 4000A receives a salt water feed FI from tank 4100 A, as well as a concentrated saline water feed C2-C from the connected concentration system 4000B. The first concentration system 4000 A outputs a concentrated saline stream Cl and a dilute saline stream C2-D. The concentrated saline stream Cl follows loop (1) for storage back in first tank 4100 A. The dilute saline stream C2-D is fed to the next tank 4100B. The concentrated saline stream Cl mixes with the existing content of tank 4100A. The concentrated saline stream C2-C is the concentrated salt water stream of the consecutive loop (i.e., loop (2)) and is fed to the dilute side of the concentration system 4000A, resulting in the production of dilute saline stream C2-D being fed to the next tank 4100B.

Similarly, in the simplified three-concentrator system of Fig. 13, the second concentration system 4000B receives a salt water feed F2 from tank 4100B, as well as a concentrated saline feed C(n- 1 )-C from the connected concentration system 4000C. The second concentration system 4000B outputs the concentrated saline stream C2-C (loop (2)) and a dilute saline stream C(n- 1 )-D. The concentrated saline stream C2-C follows loop (2) for input back into first concentration system 4000A. The dilute saline stream C(n- 1 )-D is fed to the next tank 4100C. The dilute saline stream C(n- 1 )-D mixes with the existing content of third tank 4100C. The third concentration system 4000C receives a salt water feed F(ft-l) from tank 4100C, as well as a concentrated saline water feed C(n)-C from a connected reverse osmosis filtration system 4001. Here, it should be understood that third concentration system 4000C represents the n- th concentration system, i.e., the final concentration system in the chain. The third concentration system 4000C outputs the concentrated saline stream C (n- 1)-C (loop (n- 1 )) and a dilute saline stream C(n)-D. The concentrated saline stream C(n- 1 )-C follows loop (n- 1) for input back into second concentration system 4000B. The dilute saline stream C(n)-D is fed to the final tank 4100D. The dilute saline stream C(n)-D mixes with the existing content of final tank 4100D.

In the last loop, the dilute stream C(n)-D is fed to the tank 4100D and the mixed diluted stream is fed to the reverse osmosis system 4001, producing a concentrated saline stream C(n)-C (i.e., loop ( n )), which is fed to the last concentration system 4000C as a concentrated saline stream. The reverse osmosis system 4001 also produces a purified water stream PW. As the system 4000 operates, the concentration of the streams in each tank will increase up to the concentration limit of the concentration system or up to the saturation limit of the solution stream. Each of the concentration systems 4000 A, 4000B, 4000C may be similar to concentration system 700 of Fig. 4A or concentration system 800 of Fig. 4B.

Fig. 14 shows another alternative hybrid osmotically assisted cascade concentrator and water desalination system 5000, which also includes a plurality of concentration systems. Although only three such concentration systems 5000A, 5000B, 5000C are shown, it should be understood that this is for purposes of simplification only, and for purposes of the below discussion, any suitable number n concentration systems may be connected to one another. Each of the three concentration systems 5000 A, 5000B, 5000C has a corresponding tank 5100A, 5100B, 5100C, respectively, although it should be understood that n such tanks may be provided, along with one additional tank (i.e., tank 5100D, as will be explained in greater detail below).

As shown, the first concentration system 5000A receives a salt water feed FI from tank 5100A, with the flow being monitored and/or controlled by an intervening node 5201, as well as a concentrated saline feed C2-C from the connected concentration system 5000B. The first concentration system 5000 A outputs a concentrated saline stream Cl and a dilute saline stream C2-D. The concentrated saline stream Cl follows loop (1), where it is received by an energy recovery device 5301. The first energy recovery device 5301 receives a salt water feed from second tank 5100B as well as the concentrated saline stream Cl. The energy recovery device 5301 produces a reduced-energy saline stream, which flows through tank 5100 A for temporary storage therein, and a concentrated saline output stream F2. Node 5201 is similar to the nodes described above with regard to the previous embodiments.

The dilute saline stream C2-D is fed to the next tank 5100B, which supplies the salt water feed for first energy recovery device 5301. The concentrated salt water stream C2-C is the concentrated salt water stream produced by the second energy recovery device 5302 of the consecutive loop (i.e., loop (2)) and is fed to concentration system 5000 A, resulting in the production of the dilute saline stream C2-D being fed to the next tank 5100B.

Similarly, in the simplified three-concentrator system of Fig. 14, the second concentration system 5000B receives salt water feed F2 from first energy recovery device 5301, with the salt water feed F2 passing through second node 5202, as well as a concentrated saline feed C(n- 1 )-C from the connected third energy recovery device 5303 of the next loop. The second concentration system 5000B outputs the concentrated saline stream C2-C (loop (2)) to the second energy recovery device 5302 and a dilute saline stream, which is fed into third tank 5100C. The concentrated saline stream follows loop (2), where it is received by second energy recovery device 5302. The second energy recovery device 5302 receives a salt water feed from third tank 5100C as well as the concentrated saline stream from the second concentration system 5000B. The energy recovery device 5302 produces a dilute saline feed C(n- 1 )-F, which is fed to third (and final, or n-th) concentration system 5000C (through node 5203). The energy recovery device 5302 also produces the concentrated output stream C2-C, which is fed to first concentration system 5000A.

The third concentration system 5000C receives salt water feed C(n- 1 )-F from second energy recovery device 5302, as well as a concentrated saline feed C(n)-C from a connected reverse osmosis filtration system 5001. The third concentration system 5000C outputs the concentrated saline stream C(n- 1 )-C (loop (n-1)) to the third energy recovery device 5303 and a dilute saline stream C(n)-D, which is fed into the final, 77-th tank 5100D. The concentrated saline stream follows loop (n-1), where it is received by third energy recovery device 5303. The third energy recovery device 5303 receives a salt water feed F(n-l) from the final, 77-th tank 5100D as well as the concentrated saline stream C(n- 1 )-C from the third concentration system 5000C. The energy recovery device 5303 produces a dilute saline feed F (n), which is fed to the reverse osmosis filtration system 5001 through node 5204. The energy recovery device 5303 also produces the concentrated output stream C(n- 1 )-C, which is fed to second concentration system 5000B.

The reverse osmosis filtration system 5001 produces purified water PW and the concentrated saline C(n)-C for input to the third concentration system 5000C. Each of the concentration systems 5000A, 5000B, 5000C may be similar to concentration system 700 of Fig. 4A or concentration system 800 of Fig. 4B. Similar to the previous embodiments, the energy recovery devices 5301, 5302, 5303 may be any suitable type of energy recovery devices, including, but not limited to, a reverse electrodialysis (RED) generator, a pressure retarded osmosis (PRO) solvent separator combined with a turbine, or a pressure exchanger.

It is to be understood that osmotically assisted cascade water desalination systems, concentrators and hybrid systems are not limited to the specific embodiments described above, but encompasses any and all embodiments within the scope of the generic language of the following claims enabled by the embodiments described herein, or otherwise shown in the drawings or described above in terms sufficient to enable one of ordinary skill in the art to make and use the claimed subject matter.

Claims

CLAIMS We claim:

1. An osmotically assisted cascade concentrator, comprising:

a forward osmosis filtration unit having a feed side and a draw side, the feed side receiving a first salt water feed and producing a first concentrated saline stream from the feed side, the forward osmosis filtration unit producing a dilute draw solution from the draw side; and

a concentration system receiving a second salt water feed and the dilute draw solution, the concentration system producing a second stream of concentrated saline and a stream of dilute saline, the second stream of concentrated saline produced by the concentration system being input to the draw side of the forward osmosis filtration unit.

2. The osmotically assisted cascade concentrator as recited in claim 1, wherein the concentration system comprises a cascaded plurality of filtration stages connected in series, each of the filtration stages including a plurality of reverse osmosis filtration units connected to each other in parallel.

3. A hybrid osmotically assisted cascade concentrator and water desalination system, comprising:

a forward osmosis filtration unit having a feed side and a draw side, the feed side receiving a first salt water feed and producing a first concentrated saline stream from the feed side, the forward osmosis filtration unit producing a dilute draw solution from the draw side; a concentration system receiving a second salt water feed, the concentration system producing a stream of concentrated saline and a stream of dilute saline, the stream of concentrated saline from the concentration system being input to the draw side of the forward osmosis filtration unit; and

a reverse osmosis filtration unit receiving the stream of dilute saline from the concentration system and outputting purified water and a second concentrated saline stream, the second concentrated saline stream mixing with the dilute draw solution from the forward osmosis filtration unit to form the second salt water feed.

4. The hybrid osmotically assisted cascade concentrator and water desalination system as recited in claim 3, wherein the concentration system comprises a cascaded plurality of filtration stages connected in series, each of the filtration stages including a plurality of reverse osmosis filtration units connected to each other in parallel.

5. A hybrid osmotically assisted cascade concentrator and water desalination system, comprising:

a first forward osmosis filtration unit having a feed side and a draw side, the feed side receiving a first salt water feed and producing a first concentrated saline stream from the feed side, the first forward osmosis filtration unit producing a first dilute draw solution from the draw side;

a concentration system receiving a second salt water feed, the concentration system producing a stream of concentrated saline and a stream of dilute saline, the stream of concentrated saline being input to the draw side of the first forward osmosis filtration unit; a second forward osmosis filtration unit receiving the stream of dilute saline from the concentration system and further receiving a first portion of a third salt water feed, the second forward osmosis filtration unit outputting a second concentrated saline stream which is mixed with a second portion of the third salt water feed to form the first salt water feed, the second forward osmosis filtration unit further outputting a second dilute draw solution;

a reverse osmosis filtration unit receiving the second dilute draw solution from the second forward osmosis filtration unit and outputting purified water and a third concentrated saline stream, the third concentrated saline stream mixing with the first concentrated saline stream to form the second salt water feed.

6. The hybrid osmotically assisted cascade concentrator and water desalination system as recited in claim 5, wherein the concentration system comprises a cascaded plurality of filtration stages connected in series, each of the filtration stages including a plurality of reverse osmosis filtration units connected to each other in parallel.

7. A hybrid osmotically assisted cascade concentrator and water desalination system, comprising:

a concentration system;

a first reverse osmosis unit receiving at least a first portion of a salt water feed and producing a first reject stream and a first purified water stream, the first reject stream mixing with a second portion of the salt water feed to form a first concentrated saline stream, the first concentrated saline stream being fed to the concentration system to produce a second concentrated saline stream and a first dilute saline stream; and

a second reverse osmosis unit receiving a first portion of the first dilute saline stream and producing a second reject stream and a second purified water stream, the second purified water stream being mixed with the first purified water stream to form a purified water output stream, wherein a second portion of the first dilute saline stream mixes with a first portion of the second reject stream to form a dilute solution output stream, a second portion of the second reject stream being split into a third portion of the second reject stream and a fourth portion of the second reject stream, the third portion of the second reject stream being mixed with the first portion of the salt water feed, and the fourth portion of the second reject stream being input to the concentration system.

8. The hybrid osmotically assisted cascade concentrator and water desalination system as recited in claim 7, further comprising:

an energy recovery device receiving a second portion of the salt water feed and the second concentrated saline stream, the energy recovery device producing a second dilute saline stream and a concentrated saline output stream, the second dilute saline stream mixing with the first portion of the salt water feed received by the first reverse osmosis unit, the energy recovery device generating power from a difference in concentration between the second concentrated saline stream and the second portion of the salt water feed.

9. The hybrid osmotically assisted cascade concentrator and water desalination system as recited in claim 8, wherein the energy recovery device is a reverse electrodialysis generator.

10. The hybrid osmotically assisted cascade concentrator and water desalination system as recited in claim 8, wherein the energy recovery device comprises:

a pressure retarded osmosis solvent separator; and

a turbine.

11. The hybrid osmotically assisted cascade concentrator and water desalination system as recited in claim 8, wherein the energy recovery device is a pressure exchanger.

12. The hybrid osmotically assisted cascade concentrator and water desalination system as recited in claim 7, wherein the concentration system comprises a cascaded plurality of filtration stages connected in series, each of the filtration stages including a plurality of reverse osmosis filtration units connected to each other in parallel.

13. A hybrid osmotically assisted cascade concentrator and water desalination system, comprising:

a concentration system;

a first reverse osmosis unit receiving at least a first portion of a salt water feed and producing a first reject stream and a first purified water stream, the first reject stream being fed to the concentration system to produce a first concentrated saline stream and a first dilute saline stream; and a second reverse osmosis unit receiving the first dilute saline stream and producing a second reject stream and a second purified water stream, the second purified water stream being mixed with the first purified water stream to form a purified water output stream, wherein a first portion of the second reject stream forms a dilute solution output stream, a second portion of the second reject stream is input to the concentration system with the first reject stream, and a third portion of the second reject stream mixes with the first portion of the salt water feed.

14. The hybrid osmotically assisted cascade concentrator and water desalination system as recited in claim 13, further comprising:

an energy recovery device receiving a second portion of the salt water feed and the first concentrated saline stream, the energy recovery device producing a second dilute saline stream and a concentrated saline output stream, the second dilute saline stream mixing with the first portion of the salt water feed received by the first reverse osmosis unit, the energy recovery device generating power from a difference in concentration between the first concentrated saline stream and the second portion of the salt water feed.

15. The hybrid osmotically assisted cascade concentrator and water desalination system as recited in claim 14, wherein the energy recovery device is a reverse electrodialysis generator.

16. The hybrid osmotically assisted cascade concentrator and water desalination system as recited in claim 14, wherein the energy recovery device comprises:

a pressure retarded osmosis solvent separator; and

a turbine.

17. The hybrid osmotically assisted cascade concentrator and water desalination system as recited in claim 14, wherein the energy recovery device is a pressure exchanger

18. The hybrid osmotically assisted cascade concentrator and water desalination system as recited in claim 13, wherein the concentration system comprises a cascaded plurality of filtration stages connected in series, each of the filtration stages including a plurality of reverse osmosis filtration units connected to each other in parallel.

19. A hybrid osmotically assisted cascade concentrator and water desalination system, comprising:

a concentration system receiving at least a first portion of a salt water feed and outputting a first concentrated saline stream and a first dilute saline stream; and a reverse osmosis unit receiving the first dilute saline stream and producing a purified water output stream and a reject stream, the reject stream mixing with the first portion of the salt water feed.

20. The hybrid osmotically assisted cascade concentrator and water desalination system as recited in claim 19, further comprising an energy recovery device receiving a second portion of the salt water feed and the first concentrated saline stream, the energy recovery device producing a second dilute saline stream and a concentrated saline output stream, the second dilute saline stream mixing with the first portion of the salt water feed, the energy recovery device generating power from a difference in concentration between the first concentrated saline stream and the second portion of the salt water feed.

21. The hybrid osmotically assisted cascade concentrator and water desalination system as recited in claim 20, wherein the energy recovery device is a reverse electrodialysis generator.

22. The hybrid osmotically assisted cascade concentrator and water desalination system as recited in claim 20, wherein the energy recovery device comprises:

a pressure retarded osmosis solvent separator; and

a turbine.

23. The hybrid osmotically assisted cascade concentrator and water desalination system as recited in claim 20, wherein the energy recovery device is a pressure exchanger

24. The hybrid osmotically assisted cascade concentrator and water desalination system as recited in claim 20, wherein the concentration system comprises a cascaded plurality of filtration stages connected in series, each of the filtration stages including a plurality of reverse osmosis filtration units connected to each other in parallel.

25. A hybrid osmotically assisted cascade concentrator and water desalination system, comprising:

a reverse osmosis unit receiving at least a first portion of a salt water feed and outputting a reject stream and a purified water output stream; and

a concentration system receiving the reject stream and producing a first concentrated saline stream and a first dilute saline stream, a first portion of the first dilute saline stream mixing with the first portion of the salt water feed, and a second portion of the first dilute saline stream forming a dilute saline output stream.

26. The hybrid osmotically assisted cascade concentrator and water desalination system as recited in claim 25, further comprising an energy recovery device receiving a second portion of the salt water feed and the first concentrated saline stream, the energy recovery device producing a second dilute saline stream and a concentrated saline output stream, the second dilute saline stream mixing with the first portion of the salt water feed, the energy recovery device generating power from a difference in concentration between the first concentrated saline stream and the second portion of the salt water feed.

27. The hybrid osmotically assisted cascade concentrator and water desalination system as recited in claim 26, wherein the energy recovery device is a reverse electrodialysis generator.

28. The hybrid osmotically assisted cascade concentrator and water desalination system as recited in claim 26, wherein the energy recovery device comprises:

a pressure retarded osmosis solvent separator; and

a turbine.

29. The hybrid osmotically assisted cascade concentrator and water desalination system as recited in claim 26, wherein the energy recovery device is a pressure exchanger

30. The hybrid osmotically assisted cascade concentrator and water desalination system as recited in claim 26, wherein the concentration system comprises a cascaded plurality of filtration stages connected in series, each of the filtration stages including a plurality of reverse osmosis filtration units connected to each other in parallel.

31. A hybrid osmotically assisted cascade concentrator and water desalination system, comprising:

a concentration system receiving at least a first portion of a salt water feed and outputting a first concentrated saline stream and a first dilute saline stream; and

a reverse osmosis unit receiving the first dilute saline stream and producing a reject stream and a purified water output stream, a first portion of the reject stream mixing with the first portion of the salt water feed, a second portion of the reject stream forming a dilute saline output stream, and a third portion of the reject stream being input to the concentration system.

32. The hybrid osmotically assisted cascade concentrator and water desalination system as recited in claim 31, further comprising an energy recovery device receiving a second portion of the salt water feed and the first concentrated saline stream, the energy recovery device producing a second dilute saline stream and a concentrated saline output stream, the second dilute saline stream mixing with the first portion of the salt water feed, the energy recovery device generating power from a difference in concentration between the first concentrated saline stream and the second portion of the salt water feed.

33. The hybrid osmotically assisted cascade concentrator and water desalination system as recited in claim 32, wherein the energy recovery device is a reverse electrodialysis generator.

34. The hybrid osmotically assisted cascade concentrator and water desalination system as recited in claim 32, wherein the energy recovery device comprises:

a pressure retarded osmosis solvent separator; and

a turbine.

35. The hybrid osmotically assisted cascade concentrator and water desalination system as recited in claim 32, wherein the energy recovery device is a pressure exchanger.

36. The hybrid osmotically assisted cascade concentrator and water desalination system as recited in claim 32, wherein the concentration system comprises a cascaded plurality of filtration stages connected in series, each of the filtration stages including a plurality of reverse osmosis filtration units connected to each other in parallel.

37. A hybrid osmotically assisted cascade concentrator and water desalination system, comprising:

a concentration system receiving the reject stream and producing a first concentrated saline stream and a first dilute saline stream, a first portion of the first dilute saline stream mixing with the first portion of the salt water feed, a second portion of the first dilute saline stream forming a dilute saline output stream, and a third portion of the first dilute saline stream being input to the concentration system.

38. The hybrid osmotically assisted cascade concentrator and water desalination system as recited in claim 37, further comprising an energy recovery device receiving a second portion of the salt water feed and the first concentrated saline stream, the energy recovery device producing a second dilute saline stream and a concentrated saline output stream, the second dilute saline stream mixing with the first portion of the salt water feed, the energy recovery device generating power from a difference in concentration between the first concentrated saline stream and the second portion of the salt water feed.

39. The hybrid osmotically assisted cascade concentrator and water desalination system as recited in claim 38, wherein the energy recovery device is a reverse electrodialysis generator.

40. The hybrid osmotically assisted cascade concentrator and water desalination system as recited in claim 38, wherein the energy recovery device comprises: a pressure retarded osmosis solvent separator; and

a turbine.

41. The hybrid osmotically assisted cascade concentrator and water desalination system as recited in claim 38, wherein the energy recovery device is a pressure exchanger

42. The hybrid osmotically assisted cascade concentrator and water desalination system as recited in claim 38, wherein the concentration system comprises a cascaded plurality of filtration stages connected in series, each of the filtration stages including a plurality of reverse osmosis filtration units connected to each other in parallel.

43. An osmotically assisted cascade concentrator, comprising a concentration system receiving at least a first portion of a salt water feed and outputting a first concentrated saline stream and a first dilute saline stream, wherein a first portion of the dilute saline stream forms a dilute saline output stream, and a second portion of the dilute saline stream is mixed with the first portion of the salt water feed.

44. The osmotically assisted cascade concentrator as recited in claim 43, further comprising an energy recovery device receiving a second portion of the salt water feed and the first concentrated saline stream, the energy recovery device producing a second dilute saline stream and a concentrated saline output stream, the second dilute saline stream mixing with the first portion of the salt water feed, the energy recovery device generating power from a difference in concentration between the first concentrated saline stream and the second portion of the salt water feed.

45. The osmotically assisted cascade concentrator as recited in claim 44, wherein the energy recovery device is a reverse electrodialysis generator.

46. The osmotically assisted cascade concentrator as recited in claim 44, wherein the energy recovery device comprises:

a pressure retarded osmosis solvent separator; and

a turbine.

47. The osmotically assisted cascade concentrator as recited in claim 44, wherein the energy recovery device is a pressure exchanger.

48. The osmotically assisted cascade concentrator as recited in claim 43, wherein the concentration system comprises a cascaded plurality of filtration stages connected in series, each of the filtration stages including a plurality of reverse osmosis filtration units connected to each other in parallel.

49. A hybrid osmotically assisted cascade concentrator and water desalination system, comprising: a plurality of concentration systems in fluid communication with each other;

a plurality of tanks; and

a reverse osmosis filtration unit,

wherein a first one of the plurality of concentration systems receives a first salt water feed from a first one of the tanks and produces a first concentrated saline stream and a first dilute saline stream, the first one of the tanks receiving the first concentrated saline stream, the first dilute saline stream being received by a subsequent one of the plurality of tanks, the first one of the plurality of concentration systems further receiving a subsequent concentrated saline stream produced by a subsequent one of the plurality of concentration systems,

wherein a final one of the plurality of concentration systems receives a final salt water feed from a preceding one of the tanks and produces a final concentrated saline stream and a final dilute saline stream, a final one of the tanks receiving the final dilute saline stream, the final concentrated saline stream being received by a preceding one of the plurality of concentration systems, and

wherein the reverse osmosis filtration unit receives a secondary dilute saline stream from the final one of the tanks and produces a secondary concentrated saline stream and a purified water stream, the final one of the plurality of concentration systems receiving the secondary concentrated saline stream.

50. The hybrid osmotically assisted cascade concentrator and water desalination system as recited in claim 49, wherein each said concentration system comprises a cascaded plurality of filtration stages connected in series, each of the filtration stages including a plurality of reverse osmosis filtration units connected to each other in parallel.

51. A hybrid osmotically assisted cascade concentrator and water desalination system, comprising:

a plurality of concentration systems in fluid communication with each other;

a plurality of tanks;

a plurality of energy recovery devices; and

a reverse osmosis filtration unit,

wherein a first one of the plurality of concentration systems receives a first salt water feed from a first one of the plurality of tanks and produces a first concentrated saline stream and a first dilute saline stream, a subsequent one of the plurality of tanks receiving the first dilute saline stream, a first one of the plurality of energy recovery devices receiving the first dilute saline stream from the subsequent one of the plurality of tanks and further receiving the first concentrated saline stream, the first one of the plurality of energy recovery devices feeding the first salt water feed to the first one of the plurality of tanks, and further feeding a subsequent salt water feed to a subsequent one of the plurality of concentration systems, wherein a final one of the plurality of concentration systems receives a final salt water feed from a preceding one of the plurality of energy recovery devices and produces a final concentrated saline stream and a final dilute saline stream, a final one of the tanks receiving the final dilute saline stream, the final concentrated saline stream being received by a final one of the energy recovery devices,

wherein the final one of the energy recovery devices receives a secondary salt water feed from the final one of the plurality of tanks, the final one of the energy recovery devices producing a secondary salt water feed and a secondary concentrated saline stream, the secondary concentrated saline stream being received by a preceding one of the plurality of concentration systems, and

wherein the reverse osmosis filtration unit receives a secondary salt water feed from the final one of the energy recovery devices and produces a tertiary concentrated saline stream and a purified water stream, the final one of the plurality of concentration systems receiving the tertiary concentrated saline stream.

52. The hybrid osmotically assisted cascade concentrator and water desalination system as recited in claim 51, further comprising a secondary energy recovery device, wherein the secondary energy recovery device receives the tertiary concentrated saline stream produced by the reverse osmosis filtration unit, prior to receipt thereof by the final one of the plurality of concentration systems, for producing energy therefrom.

53. The hybrid osmotically assisted cascade concentrator and water desalination system as recited in claim 51 , wherein each said concentration system comprises a cascaded plurality of filtration stages connected in series, each of the filtration stages including a plurality of reverse osmosis filtration units connected to each other in parallel.

54. The hybrid osmotically assisted cascade concentrator and water desalination system as recited in claim 51, wherein each energy recovery device is a reverse electrodialysis generator.

55. The hybrid osmotically assisted cascade concentrator and water desalination system as recited in claim 51, wherein each said energy recovery device comprises:

a pressure retarded osmosis solvent separator; and

a turbine.

56. The hybrid osmotically assisted cascade concentrator and water desalination system as recited in claim 51, wherein each said energy recovery device is a pressure exchanger.