Tell me about chemicals desalination plants?

Hi Nasser

Since your question is very brief, I will share with you a brief answer too.

Pre Treatment

• Ferric Chloride - Sea Water Coagulation
• Sodium Hypochlorite or Chlorine Gas - Mainly used to Protect Intake Pipe from Biological growth. Also useful to neutralize Algal Bloom.
• Sodium Meta Bisluphate - Dechlorinate Sea Water. 
• Sulphuric Acid - Sea Water pH Adjustment
• Polymer - Additive used combined with Ferric Chloride to optimize Flocculation process.
• Sodium Hydroxide - pH Adjustment

Post Treatment

• Sodium Hydroxide - 2nd Pass Boron Removal
• Anti Scalant - Additive to Protect RO from Scalling
• Sodium Hypochlorite or Chlorine Gas - Disinfection
• Liquid CO2 - Remineralization of RO Permeate Water
• Calcium Hydroxide - Remineralization of RO Permeate Water
• Fluoride - Health (tooth)

RO CIP (Clean In Place) Chemical

• SMBS
• Sodium Hydroxide
• Citric Acid
• STPP
• SLS
• EDTA

Aside some Plant also uses chemical below for UF CIP

• HCL

Best Regards

Azrin Kasman

Plant uses to remove salts from water