Clean drinking water is essential for good health and disease prevention. But according to the World Health Organization, some 663 million people — one out of every 10 people in the world — do not have access to safe water. The high cost of water purification devices keeps clean water out of reach for many communities, especially in developing countries. But science may soon help solve this problem.
Researchers have developed nano-scaled membranes that could filter contaminants from water faster and more cheaply than current methods.
Developing the perfect water filter is Baoxia Mi's goal.
Growing up in China in the 1980s, she learned the value of clean drinking water early on. Her interest in water and the environment has inspired her career. Recently, at the University of California, Berkeley, she's pioneering research in purifying drinking water and wastewater in new ways.
The environmental engineer is developing a new type of membrane that could be more efficient than today's water filtration technology and consume less energy in the process. It's made up of layers of graphene, 100,000 times thinner than a strand of human hair.
"We made it from graphite, which is a material that we use in pencils for example, so it's cheap and relatively abundant,” she said. “So we can use that, and the process that we use to make [it] from the graphite to the graphene oxide is actually quite scalable."
That means the membranes could be adapted to filter water from a faucet, as well as for large systems used to treat wastewater.
The membranes are much like a maze for water molecules. The water passes through a series of layers separated by spaces specifically designed to remove different types of contaminants.
"In order to kind of remove different targeted molecules," Mi explained, "the most direct way of thinking about it is to control the spacing that we have between the layers."
The researchers are working on further improvements, and Mi told VOA the nano-filters could be available in a few years. Her team hopes their work will contribute to finding solutions to water purification worldwide, making clean water affordable and available for people everywhere.