By Pilar Sánchez Molina on Mar 13 2020, 2:56 pm
Researchers at the University of Bath, UK, have developed a new desalination process that could become an ideal solution for remote locations affected by natural disasters.
The research team developed a prototype of a 3D printed desalination system that works with AC electricity.
They describe it as a low-power system with no moving parts.
The system combines cationic diodes based on micro-hole substrates coated with Nafion ionomer with an anion conducting membrane.
Nafion is a synthetic polymer with ionic properties produced by Chemours, a unit of the American chemical group DuPont.
"The possibility of combining ion diodes with ion resistors to form desalination circuit systems with AC power had previously been reported as a concept only," said the researchers.
This combination allowed them to create a system of four cameras printed in 3D to be configured with two internal cameras to extract and accumulate salt.
They tested the system in three different configurations with aqueous sodium chloride (NaCl) and found that it works.
However, they admitted that the experimental limitations are still significant. "The materials fail under conditions pulsed in salt water and the rectification effect must be improved," said the research group.
“A particularly weak part of the current system is the Fumasep FAS-130 rapidly degrading anionic conductor.” Scientists believe they could have a real mobile desalination unit in operation within five years.
"The system promises desalination without moving parts and without producing electrolytic waste," they said.
The system is presented in the document An AC-driven desalination / salination system based on a Nafion cationic rectifier, published on the ScienceDirect website.
The new device has the potential to be operated on mobile units powered by solar energy, the researchers said. "There are times when it would be extremely beneficial to install small solar-powered desalination units to serve a small number of homes," added co-author Frank Marken.
Desalination plants are a vital source of clean water in many parts of the world, and there are several thousand plants in operation in 150 countries.
However, desalination processes generally require energy intensive use and further improvements are needed to expand the use of this technology worldwide.