Chapter: Science & Technology
Topic: Desalination Technology and
Q. What is Desalination Technology and how it is important for India?
Desalination refers to the process by which pure water is
recovered from saline water by the application of energy. The commercially
relevant desalination processes are broadly classified as thermal and membrane
Q. How Desalination Technology works?
The Low Temperature Thermal Desalination (LTTD) is a process
by which warm surface seawater is flash evaporated under low pressure and
condensed with cold deep seawater, for generation of freshwater. The LTTD
technology does not require any chemical pre and post-treatment of seawater. The
technology is completely indigenous, robust and environment friendly.
Q. What is the achievement of India in Desalination Technology?
The ESSO has set up till date 4 Low Temperature Thermal
Desalination (LTTD) plants successfully in the country, one each at Kavaratti,
Minicoy, Agatti, Lakshadweep and at Northern Chennai Thermal Power Station (NCTPS),
Chennai. Out of these four plants, the Minicoy and Agatti plants were
established in April 2011 and July 2011, respectively. The capacity of each of
these LTTD plants is 1 lakh litre per day of potable water. According to the
cost estimates made recently by an independent agency for LTTD technology, the
operational costs per litre of desalinate water currently works to be 19 paisa.
The ESSO had earlier demonstrated a LTTD offshore desalination Plant of 1 MLD
capacity in April 2009 about 40 km off Chennai on a barge. Currently, a project
document of 10-MLD plant is being prepared after conducting the prefeasibility
studies. Due to the safe drinking water which is being supplied by the
Desalination Plant in Kavaratti since May 2005, the waterborne diseases, have
come down to less than 10 percent. This technology has now been stabilized and
uses very low amount of electricity and is being operated by local people.