Australian Centre for Water
and Environmental Biotechnology

Energy Neutral Treatment Plants a Possibility

Thursday, 22 September 2016
  • Professor Zhiguo Yuan in the AWMC laboratory

Wastewater treatment takes a lot of power, but what if sewage treatment could be managed while producing energy?

Professor Zhiguo Yuan’s team from the University of Queensland will work to make this a reality with a Zero-Energy Sewage Treatment Project, thanks to the collaboration of several industry partners and an Advance Queensland Innovation Partnership Grant.

"Modern sewage treatment practices have been evolving for over 100 years, but we believe our new technology will create a revolutionary change,” Professor Yuan said.

“We are taking proactive measures to achieve energy neutrality.

"Treating wastewater is economically and environmentally expensive."

The current efforts attempting to achieve energy neutrality involve major infrastructure upgrades to an existing plant, and require substantial capital investment.

The new FNA-biogas technology developed by Yuan’s team at the Advanced Water Management Centre is flexible enough that it can be retrofitted to both large and small sewage treatment plants, meaning the economic and environmental benefits can be delivered to both metropolitan and regional communities.

By adding wastewater derived Free Nitrous Acid (FNA) to a wastewater produced sludge, the proportion of biodegradable organics in the sludge is increased, meaning more biogas can be produced. 

FNA can also be used to target specific, unwanted bacteria in wastewater treatment reactors, releasing more organics for bioenergy recovery.

 “Lab results have shown that this technology increases bio-energy production to at least 3 times the current levels, and reduces energy consumption by 10 percent,” Professor Yuan said.

“This new technology is very easily adoptable, it doesn’t require much retrofitting, and the payback time is less than a year.”

“We expect the technology to be taken up widely within ten years.”

“If applied to just half the sewage treatment plants in Australia we would already be able to expect an economic benefit of 30 to 50 million dollars a year.”

The amount of renewable energy produced using this technology will also be accompanied by a substantial reduction in greenhouse gas emissions.

This will represent a major step forward for water utilities to achieve greenhouse neutral sewage management.

The three year project involves partnerships with Southern Cross University, Queensland Urban Utilities, City of Gold Coast, Wide Bay Water Corporation, South Australian Water Corporation, and Western Australia Water Corporation.