Extraction of caustic soda from desalination waste

Is there an efficient way  to extract caustic soda from desalination waste so that we can reuse it?

Thank you!

Taxonomy

• Sea Water Desalinisation
• Sustainable Desalination
• Desalination

6 Answers

1. The desalination waste not contain  sodium  but can be converted into material can be converted into useful chemicals — including ones that can make the desalination process itself more efficient.

   The approach can be used to produce sodium hydroxide, among other products. Otherwise known as caustic soda, sodium hydroxide can be used to pretreat seawater going into the desalination plant. This changes the acidity of the water, which helps to prevent fouling of the membranes used to filter out the salty water — a major cause of interruptions and failures in typical reverse osmosis desalination plants.This very concentrated brine has to be handled carefully to protect life in the ocean, and it’s a resource waste, and it costs energy to pump it back out to sea,” so turning it into a useful commodity is a win-win, Kumar says. And sodium hydroxide is such a ubiquitous chemical that “every lab at MIT has some,” he says, so finding markets for it should not be difficult..

    

2. Hello Mr. Saba, 

   Desalination waste as such does not contain caustic soda. It is merely sodium chloride solution (brine) with variety of other impurities. After removal of other impurities the brine, by electrolysis, needs to be converted into caustic soda. 

   Once that done, the caustic solution after evaporation & concentration can be converted into caustic. 

   Brine is important raw material for caustic industry. 

3. Hi Saba,  not quite sure what the other responders are proposing.  Just to say caustic is highly soluble and therefore rather difficult to extract from your brine.  So as a suggestion you may be able to extract everything else leaving you a caustic solution.  The only way I can think of that may be economically viable is the process of freeze crystalization whereby you super-concentrate your brine by freeze desalination (e.g. hybrid-ice process) leaving behind the most soluble components. Just some thoughts - good luck 

4. Think so. Like to know a little more--volume, flow expected....we can remove micro as well as some solvents. I can send you a PDF should that help you determining. 

   Use jimquigey5@gmail.com

   1 Comment

   1. Jim Quigley please upload the PDF for all members benefit

5. We are consulting for the same to our client, a new project. Please share the details at servicesenvirochem@gmail.com

   1 Comment

   1. Hi Sameer, please can you provide some insight as to approach for everyone's benefit

6. Probably. I am on the Board of Nereid (nereidwater.com ). What would be the volume of water and context in which the solution would be deployed (please use my Nereid e-mail: patrick.scherrer@nereidwater.com)

   2 Comments

   1. Hi Patrick- please can you provide some insight as to Nereid's approach for everyone's benefit

   2. Maybe, need a little more info Filtration system for micro and  more. Can you send me additional info--size, volume, goals

      PDF if you need

      Use Jim quigley5@gmail.com