Green alchemy to increase wastewater recycling
Published in Earth & Environment and Microbiology
Rising rural populations, drought and climate change are making water scarcity a problem in country townships – with more efficient handling of sewage system wastewater part of the solution.
Pioneered by Flinders University environmental health experts, local councils in South Australia are operating sustainable energy-efficient sewage treatment operations with low-cost high-rate algal pond (HRAP) systems.
Now new research led by Flinders University is investigating improved effluent treatment and biosolids removal with ‘sequencing batch reactors’ – or low-cost ‘SBR-HRAP’ technology field trials – installed at SA Water’s Angaston wastewater treatment plant in the Barossa Valley.
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, says Professor Howard Fallowfield, from the College of Science and Engineering at Finders University.
The SBR techniques under development involve a new kind of algae and improved removal of waste from the water, for better quality non-potable water for use in parks, gardens, sporting fields and other purposes.
“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,” says 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.”
Large high-rate algal pond systems, which have been treating wastewater at local council-owned facilities near Kingston-on-Murray (since 2013) and Peterborough (since 2018) in South Australia, use low-energy paddlewheels to move township and business organic waste along shallow channels where harmless green microalgae and bacteria remove pathogens and contaminants.
PhD candidate Felipe Sabatté, who has used a native freshwater filamentous algal population to produce higher quality clarified treated effluent, says the latest developments will be scaled up in the Angaston field trials.
“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,” says Mr Sabatté.
“These larger filamentous algae offer the prospect of easier separation from the treated
wastewater, significantly improving treated effluent quality.”
The outcome of this research provides 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, he says.
See more, ‘High-rate algal ponds operated as sequencing batch reactors: Towards wastewater treatment with filamentous algae’ (2025) by Felipe Sabatté, Ryan Baring and Howard Fallowfield, just published in the Journal of Applied Phycology - DOI: 10.1007/s10811-025-03545-6
First published 13 June 2025 - https://doi.org/10.1007/s10811-025-03545-6
This research was conducted by the Australian Research Council Industrial Transformation Training Centre for Biofilm Research and Innovation and funded by the Australian Government.
Also at the Angaston trial site, Flinders ARC Biofilm Research and Innovation Centre PhD researcher Sam Butterworth is investigating how to use this new technology to develop dense, algae-bacterial granules, which can be more readily removed from wastewater and to potentially reduce phosphorus levels.
“Algae-bacterial granule formation is a positive way for biofilms to form dense, fast-settling biomass and improve treated wastewater quality,” says Mr Butterworth.
“Using microalgae in high-rate algal ponds is increasingly seen as a better alternative to other wastewater treatment systems, such as activated sludge,” he says.
Traditional wastewater treatment methods can use more energy and water and can be less sustainable due to higher greenhouse gas emissions.
An independent validation of the HRAP projects approved the treated wastewater to be used for non-food crop irrigation. For example, the Kingston-on-Murray ponds supply reuse water to irrigate a woodlot, and the ponds in Peterborough provide reuse water for a golf course and a sports field.
Searching for better solutions to wastewater through algal research
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Journal of Applied Phycology
The Journal of Applied Phycology focuses on the rapidly expanding subject of the commercial use of algae.
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Algal Biostimulants and Biofertilizers
Algae have been increasingly explored as a viable source of biostimulants and biofertilizers in agriculture. In recent years, several studies have shown that algal and cyanobacterial extracts as well as biomasses can perform better than conventional products and are more environmentally friendly.
Algal biostimulants are designed to stimulate the growth of crops and improve their overall health. They can be used to enhance nutrient uptake, increase tolerance to biotic and abiotic stresses, and improve quality traits. Algal and cyanobacterial biofertilizers can be used to improve soil fertility, increase crop yields, and reduce the need for chemical fertilizers. They can also help to reduce soil erosion, increase water retention, and reduce water and soil pollution.
We believe that the Phycology community can offer a promising route to help agriculture achieve its greatest challenges in this century: sustainability and food security in a climate changing world.
Seaweed, microalgae, and cyanobacteria researchers are all invited to submit to this Topical Collection. Here we aim to showcase high quality research focusing on agricultural applications, including the role of algal biostimulants in seaweed aquaculture.
Topical areas include but are not limited to:
- Extraction, treatment, production, and application processes.
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Articles on this topic published in the journal from January 2022 to March 2023 were retrospectively added to this Collection.
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Algal Biotechnology in Wastewater Treatment: Challenges, Advances, and Opportunities
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As global challenges related to water scarcity, pollution, and climate change continue to intensify, the need for innovative, environmentally sustainable, economically viable, and scalable wastewater treatment solutions has never been greater.
Despite their considerable potential, several challenges must be addressed to facilitate the large-scale implementation of algal treatment systems. These include enhancing nutrient uptake efficiency, managing microbial interactions, maintaining system stability under fluctuating environmental conditions, improving biomass harvesting processes, and integrating algal technologies into existing treatment infrastructure. In addition, economic feasibility and evolving regulatory frameworks remain key factors influencing adoption.
This Topical Collection aims to bring together cutting-edge research that addresses these challenges and advances the development and application of algae-based wastewater treatment technologies. We welcome submissions on topics including, but not limited to:
- Algal species selection and cultivation strategies for wastewater treatment
- Nutrient removal and recovery from wastewater streams using microalgae and macroalgae
- Integration of algal systems with conventional wastewater treatment technologies
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All submissions will be handled by the journal's Editorial Board, undergo standard peer review, and receive a final decision from the Editor-in-Chief.
Manuscripts should be prepared in accordance with the journal submission guidelines.
Important: When submitting your manuscript, please ensure that this Topical Collection is selected during the submission process.
Publishing Model: Hybrid
Deadline: Ongoing
