RO for Sodium-free Water

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What is the best reverse osmosis (RO) system to get sodium-free water? 

What should be the specifics of the RO system to achieve extremely low levels of sodium in water? 

Are there any cheaper methods than RO which can produce water with extremely low sodium?

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13 Answers

  1. Ibrahim, your post still incomplete, needs more details about type of raw water, physical analysis, chemical analysis including sodium level and temp as well.

    What about the specific quality of the required permeate? 

    There are different methods for treating sodium, the optimum treatment technology is based on the raw water quality and the required permeate.

    Could you share your raw water analysis, required permeate and purpose of permeate?

     

  2. How much PPM sodium in water and what is acceptable concentration you need and what is the volume of water per day you need to treate ?

  3. ED..EDR..Membrane desalination process would be a more economic option than RO ,with better hydraulic efficiency for high sodium ..brackish water ...combo with nano filtration as a good alternative even to multipass and Combo RO systems,perhaps

    1 Comment

    1. A second pass of the RO reject water through a vibrating membrane system will result in a further 15 to 20% reduction in sodium. The reject water from the vibrating membrane would be highly brackish though which you will have to consider how to dispose of. You could pump the reject into drying beds if there is a lot of sun in your region and low humidity.

  5. As many have correctly pointed out ,the levels that you are starting with and the levels you need to reach will drive the technology solution.  Don't forget to consider NF (nano-filtration) as an option.  NF does not have the rejection of High Rejection PA but still provides good "softening" and may get you were you need to be.  The lower driving pressures will equate to lower horsepower and thus lower electrical operating costs over time.  Cheers!

  6. Dear Ibrahim EI Salhi

    For Sodium removal PA membrane may be used.High-performance multi-functional reverse osmosis membranes obtained by carbon nanotube·polyamide nanocomposite. Polyamide reverse osmosis membranes containing carbon nanotubes with acidic groups (CNTa), graphene oxide (GO), and both CNTa and GO (CNTa–GO) were prepared by the interfacial polymerization of trimesoyl chloride solutions in hexane and  m -phenylenediamine aqueous solutions containing carbon nanomaterials. All of the polyamide membranes containing the carbon nanomaterials showed considerably improved membrane performances, such as water flux, chlorine resistance, long-term durability, and mechanical properties, compared to the polyamide membrane without any of the carbon nanomaterials due to the advantageous properties of the CNT and GO as the filler materials.

    aromatic PA membranes using a support consisting of a porous polysulfone layer deposited on a polypropylene nonwoven. These support membranes soaked sequentially in MPD and TMC solutions, to synthesize the aromatic PA membrane by interfacial polymerization. In order to incorporate MWCNT into the PA membrane, an anionically stabilized dispersion of MWCNT (mixed with the MPD solution and the synthesis  conducted similarly. The softener puts out copious amounts of sodium---and while the reverse osmosis unit may initially remove 80-90 percent of this sodium. 

     

  7. Good Afternoon Mr. El Sahli;

    Aquathin has been producing such systems for 37 years.  Please visit www.aquathin.com .

    Warmest regards,

     

    FOR THE BEST TASTE IN LIFE &

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    ...into another Quarter Century re-inventing the water industry !

    Think Aquathin...AquathinK !

    ( visit the all new www.aquathin.com )

     

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    & 2008 PRESIDENT'S E STAR AWARD RECIPIENT ( visit www.aquathin.com/estar2008.pps )

     

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    Alfred J. Lipshultz

    President & CEO

    Aquathin Business Center  /  950 South Andrews Avenue / Pompano Beach, FL  33069

    T 954 781 7777 / F 954 781 7336 /E info@aquathin.com  / Skype aquathinhq.alfie

     

    1 Comment

    1. Alfred Lipshultz  please add some knowledge as to your solution/unique positioning for specific use cases not just an "ad" to contact your team. Much appreciated as this is a knowledge sharing platform. Business exchange is fine, but only when backed by information that helps to educate and share information. Thank you

  8. The process may be: a) one RO pass + Continuos Electrodeionization (CEDI) ; b) Two RO pass or c)Two RO pass + CEDI.  The right election is funtion of the water's characteristics

  9. How low concentration of Na you want? What is the starting Na concentration. What is the capacity? Ultrapure water has the lowest Na concentration, but requires combination of RO and ion-exchange (EDI or polishing MB) 

  11. HAve a look to our Deep Desalination solution at www.ades.tv.

    We could reduce NA

    1 Comment

    1. jaime del Berrio  please add some knowledge as to your solution/unique positioning for specific use cases not just an "ad" to visit your tv channel. Much appreciated as this is a knowledge sharing platform. Business exchange is fine, but only when backed by information that helps to educate and share information. Thank you

  12. Pls. contact our specialist at info@paere.nl

    2 Comments

    2. Heiko Blokpoel  please add some knowledge as to your solution/unique positioning for specific use cases not just an "ad" to contact your team. Much appreciated as this is a knowledge sharing platform. Business exchange is fine, but only when backed by information that helps to educate and share information. Thank you

      1 Comment reply

  13. Depending on your feed levels and how low you want to go, you may need two pass RO or possibly RO/DI,

    If less than 10 ppm is your target, and you're starting with drinking quality water, a single pass system using standard High-Rejection PA membranes will likely do the trick.  If you want lower than that, you may need two pass RO.  If you want