Desalinization - A solution for water crisis

Why in news?

National Institute of Ocean Technology is about to set up green, self-powered desalination plant in Lakshadweep

What is desalination?

• Desalination is the process of removing salt from sea water so that it can be used for drinking, or for watering crops.
• Desalination uses thermal distillation or a reverse osmosis membrane to separate salt from the sea.
• Reverse osmosis involves applying external pressure to force solvents through a membrane from a high-solute concentration portion to a low-solute concentration area.

Around 47% of the world’s desalinated water is produced in the Middle East and North Africa alone

What is the status of desalination plants in India?

• The first desalination plant in India is Minjur in Tamil Nadu state in the year 2010.
• The second plant was inaugurated at Nemmeli in Tamil Nadu.
• The second-largest desalination plant situated in Jamnagar of Gujarat
• National Institute of Ocean Technology to set up green, self-powered desalination plant in Lakshadweep.

What is Low Temperature Thermal Desalination (LTTD)?

• The LTTD is a process under which the warm surface seawater is flash evaporated at low pressure and the vapour is condensed with cold deep seawater.

What are the advantages of desalination?

• The cost of desalination plants  have decreased tremendously
• The desalination plants could ensure water security throughout the year.
•  Use of solar energy in desalination plants can mitigate climate change.
• The quality of the water is not compromised
• The source is unlimited
• Helps preserve current freshwater supplies

Sustainable Development Goal-6 (SDG-6) - Clean water and sanitation for all

What are the disadvantages of desalination?

• Emits more greenhouse gases
• High-salinity  brine effluents affects  the marine  ecosystem
• May lead to  hypoxia
• Exacerbate climate change if renewable energy is not used as source of power
• Chemical compounds involved in pre-treatment process can be toxic to marine organisms

What is the need of the hour?

• To use renewable energy to power desalination plants
• Safe Disposal of hypersaline wastewater or brine away from the marine organisms

Quick facts

• About 2.2 billion people in the world are deprived of access to safe water.
• Nearly three out of four natural disasters are linked to water, and a quarter of the planet lives without safely managed water services or clean drinking water.
• The World Water Day (WWD) has been observed on March 22 every year since 1993
• While around 70% of Earth’s surface is covered with water, less than 1% per cent is actually drinkable.

References

1. PIB │ Low Temperature Thermal Desalination (Lttd)
2. The Indian Express │Desalination Plants