A chemical-free means of shortening the time needed to effectively disinfect water supplies has been devised by Georgia Institute of Technology researchers. Shocks of electricity are applied as nanosecond pulses to deactivate bacteria without the generation of chemical byproducts associated with chlorination and other chemical-based purification systems.

The locally enhanced electric field technology (LEEFT) quickly charges bacterial cell membranes and induces ultrafast electroporation and inactivation of the organism that brought the electricity directly to the bacteria. Gold nanotip-equipped electrodes build up concentrated charges when connected to an electric power source, enabling nanosecond pulses to travel to the membrane and destroy bacteria.

The purification process detailed in Nature Water was tested using gold nanowedges embedded on the electrode edge of a chip and Staphylococcus as model bacteria. Electrical pulses applied at 40 kV/cm for 200 nanoseconds resulted in inactivation of 95% of the bacteria. Compared to conventional electric field treatment, the LEEFT system reduces the applied electric field strength by eight times and shortens treatment duration.

The researchers suggest the technology could be integrated into the electric grid or powered by batteries.

To contact the author of this article, email shimmelstein@globalspec.com