Cheap and Portable Filter Innovation makes Wastewater safe to drink, QUT scientist says

Queensland University of Technology (QUT) researchers have built a pilot plant to test the technology that uses solar or waste heat to purify water through a membrane.

Professor Graeme Millar said the process had been developed over four years in partnership with Japanese researchers.

“I’ll give you an analogy: if you have a shower in the morning, you’ll see all the steam build up and you’ll then see it condense on your cold mirror in the bathroom — that condensed water is actually pure water,” he said.

“The basic idea is to warm salty water, and as we heat it up it creates steam. That steam can then transfer through the membrane … it becomes liquid again as it cools down.”

Salt and other impurities are filtered out by the membrane, which Professor Millar said resembled “high-technology drinking straws”.

The plant site at Banyo in Brisbane’s north treats about 1,000 litres of water each day, but he said the applications were much broader.

“Australia is always in drought somewhere, and this obviously places a lot of strain on our farmers and their livelihood,” Professor Millar said.

“Having a method that can remove the salt from the bore waters that they need — cheaply from renewable energy … that’s good value for them.”

Professor Millar said if the technology was commercialised it could be installed in modules at industrial sites to make use of waste heat.

“It goes all the way from individual farms … small communities who are using bore water … and in industry the potential applications are almost endless,” he said.

“For example, we’ve been working off the coal seam gas (CSG) industry — when they mine the gas, they get salty water from that. We’ve looked at purifying the CSG water, we’ve also looked many other areas, sea water desalination and of course … farming for agriculture.”

He said the technology could also be used in places hit by natural disasters where the water supply had been compromised.

“They are portable, they can fit in a shipping container, they’re self-powered — once we have sun, we have water coming through, we can purify that for our drinking water standard,” he said.

The trial plant is due to run for up to six months, and then further tests will be conducted at other sites.