IBM Makes Water Clean With Smarter, Energy-Efficient Purification

At IBM, a team of nanotechnology researchers charged with developing new materials for making computer chips made a surprising discovery: the material they were working with also showed promise as a water filtration/purification/desalination membrane. Scientists at IBM Research, together with collaborators from Central Glass, the King Abdul Aziz City for Science and Technology, and the University of Texas, Austin have created a new membrane that filters out salts as well as potentially harmful toxins in water such as arsenic while using less energy than other forms of water purification.

Today, one in five people lacks access to drinking water. According to the World Health Organization, arsenic-contaminated water has been a major health concern worldwide since the 1990s. Arsenic toxicity is cumulative; studies in countries where the population has had long-term exposure to arsenic-contaminated water show that one in 10 people who drink the water may ultimately die from cancers known to be caused by arsenic, including lung, bladder and skin cancer.

Membrane filtration is currently one of the most energy efficient techniques for removing salt and improving water quality. But, conventional membranes used today are easily damaged by chlorine, which is commonly added to water to prevent bacterial growth that can cause health problems. Now, the collaborative research team has designed a new concept in membrane materials that combines resistance to chlorine damage and high performance separation behavior in mildly basic conditions, making it suitable for arsenic removal in addition to water desalination.

Because of its unique chemistry, the membrane contains ionizable hydrophobes that undergo a dramatic change when they encounter mildly basic conditions they become substantially hydrophilic. In short, the membrane, which is made with fluorine materials, transforms from a low water transporting filter to a high water transporting state in a basic environment what the researchers call a water superhighway. Fortuitously, high pH also causes arsenic to become ionic resulting in a relatively easy separation by desalination membranes. Because of these conditions and reactions, when contaminated water is forced through the membrane, the arsenic is filtered out.

Category:

Science & Technology

Tags:

• water
• ibm
• research
• filtration
• membrane