US engineers turn salty seawater into drinking water with new cheap method

Sustainable water solutions

Global capacity reached 95 million cubic meters per day in 2019, and new membranes designed for boron removal could save approximately $6.9 billion annually. The team highlights that large-scale facilities, such as San Diego’s Claude “Bud” Lewis Carlsbad Desalination Plant, stand to save millions of dollars per year. These cost reductions could make seawater a more viable source of drinking water, addressing the escalating global water crisis. Supplies are projected to meet just 40 percent of demand by 2030, according to a 2023 report by the Global Commission on the Economics of Water. The advanced electrodes efficiently remove boron by trapping it within pores lined with oxygen-containing structures that specifically bind to boron while allowing other ions to pass through. However, boron must carry a negative charge to adhere to the capture sites.

The electrodes create positive hydrogen ions and negative hydroxide ions by splitting water between two layers rather than by introducing a chemical base to induce this charge. By binding with boron, the hydroxide provides the charge required for it to adhere to the positive electrode. By doing away with the requirement for a second reverse osmosis step, this method lowers expenses and energy consumption. After the is eliminated, hydrogen and hydroxide ions recombine to create neutral, boron-free water, offering a sustainable and effective method of desalinating saltwater. “Our study presents a versatile platform that leverages pH changes that could transform other contaminants, such as arsenic, into easily removable forms,” said Menachem Elimelech, a professor of Civil and Environmental Engineering and Chemical and Biomolecular Engineering at Rice University, and a co-corresponding author of the study, in a statement. Additionally, the functional groups on the electrode can also be modified to specifically bind with various contaminants, enabling more energy-efficient water treatment. The details regarding the team’s were published in the journal Nature Water.