Recycled wastewater bolsters biodiesel project

Posted 9 September 2016

Treated wastewater  irrigates pongamia treesWastewater may be fuelling the cars of the future, in a roundabout way.

Queensland Urban Utilities is using treated wastewater to irrigate almost 4000 pongamia trees at its Boonah and Toogoolawah sewage treatment plants.

Those trees are part of an Australian-first trial to produce biodiesel, said QUU spokesperson Michelle Cull.

“The seeds produced by the pongamia trees are rich in oil, which can be easily extracted and converted into biodiesel,” Cull said.

“We hope to harvest enough seeds to yield at least 12,000 litres of biodiesel every year – that’s enough to run approximately 24 cars for a year.

“The trees have been planted on four hectares of unused land around the sewage treatment plants and irrigated with treated wastewater.”

University of Queensland Professor, and global expert in pongamia, Peter Gresshoff said biodiesel was a sustainable source of energy that emitted less greenhouse gases into the atmosphere.

“The advantage of growing this particular type of tree is that their seeds produce a higher quality and quantity of oil than other biodiesel crops,” he said.

“This trial is an exciting advance from university-focused research to practical application.”

Cull said this was just the first step.

“In the next stage of the trial we’ll be establishing a research facility where we’ll test using wastewater to irrigate other crops,” she said.

“It’s all part of our renewable energy plan which aims to reduce our carbon footprint and keep costs down.”