ACWEB graduate takes home Water Journal 2021 Best Thesis Award

18 Feb 2022

A University of Queensland graduate has won the Water journal 2021 Best Thesis Award.

Dr Zhiyao Wang, a postdoctoral researcher at UQ’s Australian Centre for Water and Environmental Biotechnology, was awarded the prize for her work on innovative nitrogen conversion to enhance wastewater and sludge management.

Dr Wang’s PhD research focused on resource recovery in wastewater treatment processes.

“Sewage contains some incredibly valuable resources – water of course, but also chemical energy embedded in the organic carbon, and it also contains large amounts of the valuable nutrients that are normally lost during treatment,” said Dr Wang.

Dr Wang’s research identified a novel ammonia-oxidizing bacterium, Candidatus. Nitrosoglobus, in wastewater treatment systems.

“My research was focused on finding a way to evolve the treatment plants into a resource recovery factory.

Based on the unique physiological features of Ca. Nitrosoglobus, we were able to develop a new acidic activated-sludge process.

This new process expands the operational pH of the 100-year-old activated-sludge technology from a neutral (~7) to an acidic range (2–6),” said Dr Wang.

“This acidic activated-sludge process opens up new opportunities to promote the on-going paradigm shift in wastewater treatment plants  from pollutant removal to resources and energy recovery.”

The new acidic activated-sludge process enables nitrogen removal via anaerobic ammonium oxidation, which does not require organic carbon and allows the organics in sewage to be captured and recovered as biomethane (the main component of natural gas).

Nutrients can then be recovered through reusing sewage sludge, a by-product of sewage treatment.

The acidic activated-sludge process reduces solids concentration, inactivates pathogens, and removes toxic metals from sludge, generating Class A biosolids which qualify for unrestricted agricultural reuse.

Water is a peer-reviewed, open access journal on water science and technology, including the ecology and management of water resources, and is published semimonthly online by MDPI.