Producing clean water at a lower cost could be on the horizon, after researchers from The University of Texas at Austin and Penn State solved a complex problem that has baffled scientists for decades, until now.
According to the United States Bureau of Reclamation, 71% of our planet is covered in water, but only 3% of it is considered freshwater.
Of this 3%, 2.5% is locked up in snowpack and glaciers in the poles, meaning only 0.5% of the freshwater on Earth is easily accessible.
Desalination is a process that removes salt and chemicals from water, something that has been studied for decades but has resulted in a very lengthy and expensive process. This is due in part to complex procedures that many of the world’s scientists are still studying to this day.
The research team from UT Austin and Penn State partnered with DuPont Water Solutions and solved a very important aspect of this complexity. The scientists found out the membranes involved with desalinizing water are inconsistent when it comes to density and distribution of mass. When density of these membranes is altered at the nanoscale, it becomes increasingly easier to clean water.
According to an article from Science Daily, “Reverse osmosis membranes are widely used for cleaning water, but there’s still a lot we don’t know about them,” said Manish Kumar, an associate professor in the Department of Civil, Architectural and Environmental Engineering at UT Austin, who co-led the research.
“We couldn’t really say how water moves through them, so all the improvements over the past 40 years have essentially been done in the dark.”
The paper documents an increase in efficiency in the membranes tested by 30%-40%, meaning they can clean more water while using significantly less energy. That could lead to increased access to clean water and lower water bills for individual homes and large users alike.
In short, reverse osmosis works by having a solution and a solute. In this case, our solution would be water, and the solute would be salt. In order for reverse osmosis (desalinization) to work, you apply pressure to the salt solute on one side of a U-tube. Through complex procedures, minerals will stay on one side while clean, fresh water passes through.
This is a very short, reduced explanation of what reverse osmosis is. It takes a large amount of energy to complete this task. The research done by UT and Penn State works by improving the efficiency of the membranes used to desalinize water, which in turn could make it easier and cheaper to do.
“Fresh water management is becoming a crucial challenge throughout the world,” said Enrique Gomez, a professor of chemical engineering at Penn State who co-led the research. “Shortages, droughts, with increasing severe weather patterns, it is expected this problem will become even more significant. It’s critically important to have clean water availability, especially in low-resource areas.”
The National Science Foundation and DuPont, which makes numerous desalination products, funded the research. The seeds were planted when DuPont researchers found thicker membranes were actually proving to be more permeable. This came as a surprise, because the conventional knowledge was thickness reduces how much water could flow through the membranes.