Researchers use algae to recycle wastewater in drought-hit regions

Researchers are advancing a green solution to water scarcity by using algae to recycle wastewater in drought-stricken rural regions.

Flinders University researchers in South Australia are trialing enhanced high-rate algal pond (HRAP) systems that incorporate native filamentous algae, enabling faster, more efficient wastewater treatment and easier removal of solids, according to a statement from the university on Friday.

This breakthrough not only improves water quality for non-potable uses like irrigation, but also offers a low-cost, energy-efficient alternative to traditional sewage treatment, addressing critical water shortages faced by regional communities, the statement said.

Local councils in South Australia are using HRAP systems, where low-energy paddlewheels circulate wastewater through channels filled with microalgae and bacteria that remove contaminants, researchers said.

"Algae-bacterial granule formation is a positive way for biofilms to form dense, fast-settling biomass and improve treated wastewater quality," said Flinders University PhD researcher Sam Butterworth.

Researchers are now testing advanced "sequencing batch reactor" HRAP technology at a South Australian wastewater treatment plant, aiming to optimize biological processes for faster, more efficient wastewater treatment without major new investment.