This document discusses desalination and reverse osmosis (RO) as a method for desalination. RO uses pressure to force water through a semi-permeable membrane, removing salts and other impurities. While RO has advantages like versatility and adaptability, it faces challenges like membrane fouling and brine disposal. New technologies like forward osmosis aim to improve RO by further reducing energy use and preventing fouling issues, helping make desalination more sustainable.

1. – S A M I R E H M A N
Desalination - ‘Exploring Future Trends &
Challenges’

2. D E S A L I N A T I O N
• The process of removing salt from seawater
• Typical example is water and brine system

3. M E T H O D S U S E D F O R D E S A L I N A T I N G
W A T E R
• Sea Water Reverse Osmosis (SWRO)
• Forward Osmosis (FO)

4. In seawater RO systems, pressure is
applied to seawater forcing water through
a semi-permeable membrane while most
salts, colloids, bacteria and other
impurities are rejected by membrane

5. R O
T E C H N I C A L
A D V A N T A G E S
• Versatile - treats all types of water
brackish-seawater
• Adaptable to all sizes of installation and
energy sources eg electricity, steam
• Setting up in all geographic zones
possible
• Minimal environmental impact
• Flexibility - plant sizes;can increase
production and hence plant size to
accommodate requirement
• Operation costs proportional to flow
variations

6. Things to Think About
Membranes sensitive to
abuse & feed water
needs pre-treatment to
remove particulates
Operation - high quality
materials
Safe & careful disposal
of brine
Risk of
membranes to
bacterial
contamination

7. Process Flow Diagram - RO Plant

8. T Y P I C A L F E A T U R E S O N A N R O
P L A N T
• Standard features of RO systems inc. major components such
as cartridge filter, pressure vessels, membrane elements, high
pressure pumps and control instrumentation w/failsafe devices
• Energy Recovery Devices comprises pressure exchanger and
booster pump
• Cleaning In Place (CIP Unit) comprises cleaning pump,
cleaning tank, bag filter, instrument control panel
• Post-Treatment System comprises chemical dosing units
(neutralisation or chlorination)

10. - Membrane biofouling
- Protecting SWRO from red blossom
algae
- Need to drive down energy costs
- Treating brine reject for beneficial use
eg as salts/road salts, providing
feedstock to chemical industry
- The need for driving down capital
costs for thermal desalination units
- Environmental impact concerns for
large scale desalination

11. C H A N G E S O N T H E H O R I Z O N
• Use of Forward Osmosis technology - developments in
stand alone systems or combination technologies use
with RO => lower energy consumption
• Using waste heat in desalination => lower energy
costs

12. S U M M A R Y
• Reverse Osmosis been established
a mature and sustainable
technology for seawater treatment
• New technologies platforms such
as Forward Osmosis (FO) aim to
improve RO, and are applicable
with multiple benefits
• These process focus on reducing
energy consumption and prevent
scaling/biofouling commonly
associated with membrane
technology