Desalination Technologies
( UPSC Prelims)
Desalination Technologies
( UPSC Prelims)
News Context
Recently, scientists at IIT Bombay have created solar evaporators resembling lotus leaves for the treatment of saltwater. This innovation utilizes a novel hydrophobic graphene-based material that aids in the process of water desalination.
Desalination Technologies and Processes
| Technologies | Thermal Technology | Membrane Technology |
|---|---|---|
| Concept | Involves heating saline water and collecting the condensed vapor (distillate) to generate pure water. Usage: Primarily for seawater desalination. | Feedwater is pushed through semi-permeable membranes to separate dissolved solids. Usage: Used for brackish water desalination. |
| Sub-categories (Processes) | Divided into three groups: • Multi-Stage Flash Distillation • Multi-Effect Distillation • Vapor Compression Distillation | Divided into two groups: • Electrodialysis/Electrodialysis Reversal (ED/EDR) • Reverse Osmosis (RO) |
| Merit | • Reduces maximum salinity concentration. • Requires less input electrical energy. | • Environmentally Friendly • Requires less space. |
| Demerits | • Utilizes conventional energy sources like coal. • Involves high costs. • Prone to corrosion. | • Prone to fouling. • Needs regular maintenance. • Issues with membrane waste disposal. • May not completely remove Total Dissolved Solids (TDS) or pathogens. |
| Example | Low Temperature Thermal Desalination (LTTD) plants located in Kavaratti, Minicoy, and Agatti Islands in Lakshadweep. | Nemmeli Seawater Desalination Plant, Tamil Nadu. |