Desalination Pretreatment: Dechlorination

• Addition of Sodium (meta) bisulfite (SBS)

The dosing rate is 3:1 of SBS:Cl2 (active chlorine dose). The reaction time is about 2 minutes.

NaHSO3 + Cl2 +H2O --> NaHSO4 + 2 HCl

Na2S2O5 + Cl2 +H20 --> Na2SO4 +SO2 + 2HCl

• Granulated Activated Carbon filter

Chemisorption process where chlorine reacts with the carbon surface.

CL2 --> Cl-

Reaction time: 3 to 7 minutes
Linear velocity: 20m/h

Desalination Key Issues

Seawater Intake

Desalination Pretreatments

Desalination Post-treatments

Desalination Polishing steps

Reverse Osmosis Desalination Process

Desalination and Energy Costs

Brine Disposal

Membranes cleaning (CIP)

Storage and Distribution

Containerization

Instrumentation and Control (SCADA)