A new device could provide an environmentally friendly, cost-effective method of sterilising water.

Today, 2.1 billion people live without safe water at home and one in four primary schools have no drinking water service.

But new technology being developed at UNSW Canberra could help.

The device bubbles un-pressurised carbon dioxide (CO2) through wastewater in a bubble column, effectively inactivating both bacteria and viruses. 

Studies so far have shown it is capable of sterilising water with hot CO2, which considerably reduces the energy requirements when compared with boiling water, as heating gas is much more efficient than heating water.

It is also safer than chemical treatments, such as chlorine.

The fact that the process can use heated CO2 gas instead of heated water and the possibility of reusing exhaust gas from combustion processes makes it likely to be more energy efficient too.

Studies so far have been funded by Australian Pork Limited (APL).

APL funded the construction of a small pilot plant for pure water production from the condensation of the saturated gases from the bubble column, which was able to produce pure condensed water and also sterilise the piggery effluent, producing another output of sterilised water.

More information is available here.