Nanomembranes - Nanotechnologies for Water Environment Applications - page 397

Seawater desalination has gained much attention in the last four decades. It is
sought as a reliable water source for many coastal cities. The major driving forces
towards seawater desalination are the needs due to increase in water demand which is
caused by the increase in population and industrialization, deterioration of traditional
water supply sources, water shortage caused by long-term drought, more stringent
regulation on water quality and also the cost of water production from seawater. More
than half of the global desalination capacity uses seawater as the source water
(Wangnick/GWI, 2005). Saudi Arabia, the United States and the United Arab Emirates
are among the top 3 countries listed in the 2004 worldwide desalting plant inventory
with more than 1% of global desalting capacity (Wangnick/GWI, 2005). A list of the
seawater desalination facilities that are in operation with a capacity of more than 20 mgd
is summarized in Table 12.14.

In Singapore, the indigenous water resources have long been outstripped by
demand (Reina, 2004). In 2006, about 1.23 million m 3 of water is consumed each day by
the Singapore's population of 4.5 million; domestic usage accounts for up to 57% of this
water consumption (MEWR, 2007b). The current water supply even with the NEWater
augmentation will not be sufficient to meet the increasing demand for water. Hence,
Singapore, being an island-state country, has made use of the abundance of seawater for
reclamation and reuse. The pioneering S$200 M seawater desalination plant at Tuas,
Singapore, completed in September 2005, has a capacity of over 136,380 m 3 /d and
supplies 10% of Singapore's water demand. The lower-cost RO system has enabled the
desalinated water to be priced at S$0.78/m 3 as compared with about S$2/m 3 using multi-
stage flash (MSF) distillation (The Straits Times, 2004). This price is lower than the
water tariff for non-domestic use in Singapore, which is charged at a flat rate of
S$1.17/m 3 (PUB, 2007b). Hence, this attribute provides further incentive, especially to
the industries to use desalinated water.
Table 12.14 Seawater desalination facilities with capacity more than 20 mgd.

Capacity
(mgd)

In Operation
since

Plant Location

2007 -
planned 2003

Tampa Bay Desalination Plant 1 USA 25.0

Point Lisas Plant 2

Trinidad 28.8 2002

Carboneras - Almeria 1 Spain 32 2003

Ashkelon 1 Israel 84.5 2005

Tuas Desalination Plant 3 Singapore 36 2005

Fujairah 4 UAE 120 2003

1 Quteishat (2008). 2 Thompson et al. (2005). 3 PUB (2005). 4 Woo et al. (2005).