Rising rural populations, escalating drought, and the impacts of climate change are intensifying the challenge of water scarcity in country townships, but innovations in wastewater treatment led by Flinders University researchers are offering a promising solution.
Sustainable, energy-efficient sewage treatment operations using low-cost high-rate algal pond (HRAP) systems have already been adopted by local councils in South Australia, with notable success in communities like Kingston-on-Murray and Peterborough since 2013 and 2018.
Building on these advances, new research from Flinders University is trialling “sequencing batch reactors” — referred to as low-cost ‘SBR-HRAP’ technology — at SA Water’s Angaston wastewater treatment plant in the Barossa Valley.
Professor Howard Fallowfield, College of Science and Engineering, Flinders University said: “The good news is that the newer systems under development can work better and faster without major capital expense – due to the latest research of new approaches to bio-processing inside them.”
The SBR techniques under investigation introduce a new kind of algae and methods for better removal of waste from water, enhancing the quality of non-potable water for use in parks, gardens, and sporting fields.
“Supported by SA Water and the ARC Biofilm Research and Innovation Centre at Flinders, we are trialling selective enrichment of algal-bacterial combinations to produce higher quality treated effluent,” said Professor Fallowfield.
“Using wastewater from the Angaston community, our six pilot-scale HRAP tanks will compare the performance of these improved processes against the original HRAP operations.”
PhD candidate Felipe Sabatté, who played a significant role in the project’s development, said: “While high-rate algal ponds are an accepted method of wastewater treatment, particularly for regional and rural communities, they utilise microalgae which are difficult to remove from the treated wastewater leading to unacceptably high suspended solids in the discharge.
“These larger filamentous algae offer the prospect of easier separation from the treated wastewater, significantly improving treated effluent quality.”
Further enhancements are being explored at the Angaston site. PhD researcher Sam Butterworth said: “Algae-bacterial granule formation is a positive way for biofilms to form dense, fast-settling biomass and improve treated wastewater quality.
“Using microalgae in high-rate algal ponds is increasingly seen as a better alternative to other wastewater treatment systems, such as activated sludge.”
Traditional methods, by contrast, can use more energy and water and result in higher greenhouse gas emissions.
Independent validation has shown that HRAP-treated wastewater is safely used for non-food crop irrigation.
Ponds in Kingston-on-Murray supply water to a woodlot, while those in Peterborough irrigate a golf course and sports field.
“These developments offer a new operational strategy for wastewater HRAPs, particularly for the benefit of regional and rural communities challenged with water restrictions and to help meet UN SDG6 [clean water and sanitation] targets in the long run,” added Sabatté.
This research, undertaken by the Australian Research Council Industrial Transformation Training Centre for Biofilm Research and Innovation with government funding, positions South Australia as an innovator in tackling water scarcity — demonstrating that integrating green technology and collaborative science delivers results with far-reaching potential.