Desalination for Water Supply
FR/R0013
Feb 2006
Summary
The over-exploitation of existing fresh water supplies is
becoming a problem in many parts of the world. There are many causes,
the principle ones being population growth, demands for higher living
standards, growth of both agriculture and industry, and climate change.
Water shortages are forecast to increase, especially in urban areas
where the demand for water is growing. Even in the UK potential
problems with shortages in the water supply are starting to appear. In
many areas desalination is being considered as a possible solution to
the problem.
‘Desalination’ is the term used to describe a group
of processes for reducing the salt content of brackish and sea waters
to turn them into a drinkable supply. There are over 15,000
desalination plants in more than 120 countries. About half of the
plants are located in the Middle East and the number is growing. It has
been estimated that there will be a 100% increase in the active
installed capacity of desalination plants during the period 2005-2015.
All desalination processes use chemical engineering technology in which
a stream of saline water is fed to the process equipment, energy in the
form of heat, water pressure or electricity is applied, and two outlet
streams are produced, a stream of desalinated (fresh) water and a
stream of concentrated brine which must be disposed of. This review
describes, with the aid of diagrams, the most commonly used processes
for desalination. It also provides an historical perspective,
information on trends in the application of desalination, costs and how
the salinity affects the palatability of water supplies.
The review contains 24 pages (A5), including a bibliography and
references.
Copies of this report are available from the Foundation price
£15.00, less 10%, for FWR members.