A chemical engineering professor at The University of Texas at Austin is part of a team that has developed a new chlorine-tolerant membrane that should simplify the water desalination process, increasing access to fresh water and possibly even reducing greenhouse gases.
we make the desalination process more efficient with better membranes, it will
be less expensive to desalinate a gallon of water, which will expand the
availability of clean water around the world,” Professor Benny Freeman says.
worked primarily with James McGrath of Virginia Tech University and Ho
Bum Park of the University of Ulsan in South Korea for more than three
to develop the chlorine-tolerant membrane made of sulfonated
patent has been filed.
must be added to water to disinfect it to prevent a biofilm (stemming from
biological contaminants in the raw water) from forming on the membrane, which
would reduce its performance. It then is de-chlorinated prior to sending it
through the currently used polyamide membranes, which don’t tolerate
promises to eliminate de-chlorination steps that are required currently to
protect membranes from attack by chlorine in water,” Freeman says. “We believe
that even a small increase in efficiency should result in large cost savings.”
development also could have a direct impact on reducing carbon-dioxide
emissions, which contribute to global warming.
“Energy and water are inherently connected,” Freeman says.
“You need water to generate power (cooling water for electric power-generation
stations) and generation of pure water requires energy to separate the salt
from the water. That energy is often generated from the burning of fossil
fuels, which leads inevitably to the generation of carbon dioxide. Therefore,
if one can make desalination more energy-efficient by developing better
membranes, such as those that we are working on, one could reduce the carbon
footprint required to produce pure water.”
says McGrath and his research group developed novel materials based on an
entirely different platform of membranes than those used today in desalination
membranes. These new materials are extremely tolerant to aqueous chlorine so
their performance doesn’t deteriorate in the presence of chlorine.
Dr. McGrath radically changed the chemical composition of the membranes,
relative to what is used commercially, and the new membranes do not have
chemical linkages in them that are sensitive to attack by chlorine,” says
Freeman, who holds the Kenneth A. Kobe Professorship in Chemical Engineering
and the Paul D. & Betty Robertson Meek & American Petrofina Foundation
Centennial Professorship in Chemical Engineering.
The research is
published in the German Chemical Society’s journal Angewandte Chemie. Funding
for the research was provided by the Office of Naval Research and the National
Science Foundation-Partnerships for Innovation Program.
Chlorine-tolerant Desalination Membrane May Boost Access to Clean Water
August 14, 2008