Caitlin Cunningham is contributing editor for Water & Wastes Digest. For more information, contact WWD at [email protected]
Aug 16, 2011

RO for Desal

Reverse osmosis has come a long way since its first successful salt rejection application in 1959.
Critics of RO desalination have pegged the process as too costly or too energy intensive, but
upfront prices continue to drop, technology is advancing and alternative energy sources are more
prevalent than ever.
All the large-scale RO desalination facilities in the U.S. are newer, many having started up in
just the past decade. More than 1,300 desalting plants are at work nationwide, producing 400
million-plus gal of (mostly potable) water per day, according to a 2007 report from the American
Membrane Technology Assn. Some of these facilities use membranes to remove salt from water,
and some employ thermal methods. It is vital to the future of RO desalination, especially here in
the U.S., that we keep a close eye on the membrane operations and learn from their experiences.
Several industry experts are predicting that the RO desalination market will grow significantly
in the coming decade—both domestically and abroad—and I wholeheartedly agree. In the
U.S., expect to hear more about RO on the coasts, in areas with saline groundwater and where
population counts are closing in on or already exceeding water capacity. Rather than establish
new water systems from scratch, utilities serving these areas may find that tapping into existing
sources and applying RO for desalination proves to be a more cost-effective, environmentally
friendly and publicly accepted decision.