Revolutionary Tech Transforms Seawater to Drinking Water: No Chemicals Needed!

New carbon fabric electrodes that extract boron from seawater—a crucial step in converting saltwater into safe drinking water—could replace pricey chemicals in water desalination facilities.

Engineers from Rice University and the University of Michigan have published a report in Nature Water that details the new method.

Seawater naturally contains boron, which can infiltrate traditional salt-removal filters and turn into a hazardous drinking water pollutant. The boron levels in seawater are five to twelve times greater than what many agricultural plants can withstand, and they are about twice as high as the WHO's most permissive standards for safe drinking water.

According to Jovan Kamcev, an assistant professor of chemical engineering and macromolecular science and engineering at U-M and a co-corresponding author of the study, "most reverse osmosis membranes don't remove very much boron, so desalination plants typically have to do some post treatment to get rid of the boron, which can be expensive." "We developed a new technology that's fairly scalable and can remove boron in an energy-efficient way compared to some of the conventional technologies."

Since boron is electrically neutral boric acid in saltwater, it can flow through reverse osmosis membranes, which normally remove salt by repelling ions, which are electrically charged atoms and molecules.
In order to overcome this issue, desalination facilities typically treat their water by adding a base, which makes boric acid negatively charged. The freshly charged boron is eliminated by another step of reverse osmosis, and acid is then added to neutralize the base. Those additional measures in treatment can be expensive.

Weiyi Pan, a postdoctoral researcher at Rice University and a co-first author of the study, stated, "Our device reduces the chemical and energy demands of seawater desalination, significantly enhancing environmental sustainability and cutting costs by up to 15 percent, or around 20 cents per cubic meter of treated water,"

With a desalination capability of 95 million cubic meters per day worldwide in 2019, the new membranes might result in yearly savings of about $6.9 billion. Huge desalination facilities, like the Claude "Bud" Lewis Carlsbad Desalination Plant in San Diego, have the potential to save millions of dollars annually.

These kinds of savings could help ease the escalating water crisis and make seawater a more accessible source of drinking water. A research published in 2023 by the Global Commission on the Economics of Water projects that by 2030, freshwater supplies will be able to supply 40% of demand.