Graduates advance water treatment through nanobubble technology
9 May 2025
Greater Western Water (GWW) has become the first utility in Australia to pilot nanobubble technology, with its graduate engineers successfully delivering improved Class C recycled water quality as part of the wastewater treatment process.
In 2022, graduate engineer Samuel Leong proposed a trial to explore the potential of nanobubble technology in wastewater treatment. Building on this initiative, graduate Roshi Selvakumar carried the project forward in collaboration with Custom Fluids, to successfully implement the trial in 2024.
Their technical paper, detailing the trial and its outcomes, was awarded second place at a water industry conference - a testament to the quality of their work and its significance within the industry.
General Manager of Strategy and Partnerships, Kessia Thomson said the project highlights the potential of emerging technologies to improve the quality of recycled water, with the added benefit of being driven by graduates who represent the next generation of industry leaders.
"Led by two graduate engineers, this trial has delivered valuable operational insights while offering early-career professionals the chance to take ownership of a real-world, impact-driven innovation." said Ms Thomson.
The small-scale trial was conducted at GWW’s Bacchus Marsh Recycled Water Plant and aimed to heighten and maintain the dissolved oxygen (DO) levels in one of the site’s operational lagoons. By improving DO levels, the nanobubbles support a more natural process, reducing the need for chemicals and enhancing overall treatment efficiency.
As a result, the trial met its intended aim and produced a much higher quality of Class C recycled water. Class C recycled water is used across agriculture, industry, and community spaces for purposes such as irrigation, dust suppression, and roadworks. Improving water quality not only increases customer confidence but also strengthens environmental outcomes by reducing nutrient discharge, protecting waterways, and promoting sustainable resource use.
The next phase will involve a follow-up trial exploring the use of additional technology in the lagoon to further improve the quality of recycled water.
