Desalination Technology:
The Defence Research & Development Organisation (DRDO) has developed an indigenous high-pressure nanoporous multilayered polymeric membrane for seawater desalination.
- The project was executed by Defence Materials Stores Research & Development Establishment (DMSRDE), Kanpur, under the Aatmanirbhar Bharat
- The membrane was designed to meet the operational needs of the Indian Coast Guard (ICG), particularly to withstand chloride ion-induced instability in saline water.
- The technology is intended for use in Offshore Patrol Vessels (OPVs) of the Coast Guard, providing self-reliant onboard freshwater capability.
- Desalination is the removal of dissolved salts and minerals from saline or brackish water to make it fit for human use.
- Two primary technologies used globally:
- Reverse Osmosis (RO) – pressure-driven membrane-based filtration.
- Thermal Desalination – evaporation-condensation method using heat.
- A desalination plant converts seawater into freshwater by removing salts to meet drinking or industrial quality standards.
Working of Reverse Osmosis (RO) Desalination:
- Osmosis refers to the natural movement of water from an area of low solute concentration to high solute concentration through a semi-permeable membrane.
- In reverse osmosis, external pressure is applied to push water from a high-solute (saline) side to a low-solute (freshwater) side, against the natural osmotic gradient.
- Microscopic pores in the RO membrane allow water molecules to pass while blocking salts and other impurities.
- Seawater typically has a TDS (Total Dissolved Solids) of ~35,000 ppm, while RO brings it down to 200–500 ppm, making it potable.
