A method of flow-electrode capacitive deionization (FCDI) desalination of brine or brackish feed water solution comprising the steps of:
- a. introducing the brine or brackish feed water solution into an FCDI desalination cell, the cell comprising
- i. a tubular housing having an upper end and a lower end, a first interior annular fluid flow space extending between the upper and lower ends, a feed solution inlet port proximate the lower end in fluid communication with the first interior annular fluid flow space, and a treated solution outlet port proximate the upper end in fluid communication with the first interior annular fluid flow space;
- ii. an tubular upper end cap attached to the tubular housing upper end and comprising an internal annular upper end cap space, an upper seal member sealing the upper end of the tubular housing, and an upper end cap outlet port in fluid communication with the internal annular upper end cap space, the upper seal member isolating the internal annular upper end cap space from the tubular housing first interior annular fluid flow space;
- iii. an tubular lower end cap attached to the tubular housing lower end and comprising an internal annular lower end cap space, a lower seal member sealing the lower end of the tubular housing, and a lower end cap inlet port in fluid communication with the internal annular lower end cap space, the lower seal member isolating the internal annular lower end cap space from the tubular housing first interior annular space;
- iv. a plurality of tubular membranes oriented in parallel relationship to each other, each tubular membrane having a lower end, an upper end, an outer surface and an inner tubular space therebetween, each tubular membrane being mounted within the cell so that the lower end of each tubular membrane is in fluid communication with the internal annular lower end cap space, so that the lower end of each tubular membrane passes in sealed fashion through the lower seal member, so that each tubular membrane extends through the first interior annular fluid flow space, so that the upper end of each tubular membrane passes in sealed fashion through the upper seal member, and so that the upper end of each tubular membrane is in fluid communication with the internal annular upper end cap space, each tubular member connecting the internal annular lower end cap space and the internal annular upper end cap space in fluid communication;
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- v. a plurality of electrodes extended through each respective tubular membrane inner tubular space, respectively, wherein approximately one half of the plurality of electrodes each has a positive polarity, wherein the remainder of the plurality of electrodes each has a negative polarity, and wherein the negative and positive polarity electrodes are evenly distributed through the plurality of electrodes to create a plurality of pairs of tubular membranes having opposite polarity;
- wherein the internal annular lower end cap space is capable of receiving a carbon slurry through the lower end cap inlet port, wherein the carbon slurry is capable of moving through the inner tubular spaces of the plurality of tubular members into the internal annular upper end cap space and then out the upper end cap outlet port;
- b. pressurizing the feed water solution to a first pressure P1;
- c. applying a positive polarity to the approximately one half of the plurality of electrodes designated to have a positive polarity;
- d. applying a negative polarity to the remaining approximately one half of the plurality of electrodes designated to have a negative polarity;
- e. introducing the carbon slurry into the cell internal annular lower end cap space, at a second pressure P2, through the lower end cap inlet port, urging the carbon slurry to pass through the inner tubular spaces of the plurality of tubular members, into the internal annular upper end cap space and then out of the upper end cap outlet port;
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- f. directing the treated solution out the treated solution outlet port to a desired location.