Chinese scientists develop new material for seawater desalination

NANJING -- A team of Chinese scientists has developed a polyester thin film that can enhance desalination and water purification technology, with the findings published in the international journal Science on Friday.

The research team led by Zhang Xuan, a professor at the Nanjing University of Science and Technology, developed the polyester reverse osmosis membrane, which overcame several limitations of mainstream commercial polyamide membranes, providing a new solution for the next generation of seawater desalination technology.

Reverse osmosis membranes exhibit sufficient performance in terms of water permeability and salt rejection; however, they are vulnerable to degradation in the presence of chlorine or other strong oxidants.

Zhang explained that seawater needs to be chlorinated in the pre-treatment process for desalination, but chlorine-containing substances cause damage to the chemical structure of the polyamide film, and even directly degrade it. So, seawater must be dechlorinated after chlorination before it can enter the reverse osmosis filtration process.

The new material shows impressive resistance to hydrolytic degradation and complete resistance to chlorine, which can offer a path to considerably reducing pre-treatment steps in desalination.