New technology enables better stormwater treatment

Curtin University researchers have found that a new stormwater treatment device improves treated water quality by as much as 80%, in a development that could prevent harmful pollutants from entering waterways and cut recycling and infrastructure costs for authorities globally.

Carried out in collaboration with Urban Stormwater Technologies (UST) and published in the Journal of Environmental Management, the research demonstrated how a new design of catch basin insert (CBI) treated stormwater more thoroughly at the source by removing gross pollutants such as leaves and plastic, as well as smaller dissolvable pollutants — the vast majority of which are not captured by previous designs.

The research was part of the PhD thesis of Dr Zahanggir Alam, from Curtin’s School of Civil and Mechanical Engineering. He said the new CBI uses a specifically developed filtration material and was shown to capture 95% of waste entering the drain while improving treated stormwater quality by 80%.

“By removing dissolvable pollutants such as nutrients from stormwater run-off, the CBI can help arrest the declining health of waterways such as Perth’s Swan and Canning rivers and the ocean,” he said.

“Excessive nutrients in our rivers create a lack of oxygen in the water that can kill fish and also leads to algal blooms that block the sun and prevent photosynthesis by plants — all of which harms entire river and marine ecosystems.”

Research principal supervisor Associate Professor Faisal Anwar said the new design of CBI offers economic as well as environmental benefits, and could potentially revolutionise the way stormwater is treated.

“Government and local councils spend a lot of money trying to reactively manage stormwater contamination and this solution could possibly present a vastly more efficient and cost-effective way of treating stormwater when all reactive costs are considered,” Assoc Prof Anwar said.

“There are many billions of dollars’ worth of stormwater infrastructure already in the ground in Perth and this new technology has the potential to transform what is currently the major source of urban waterway contamination into a new water resource.”

(L–R) Urban Stormwater Technologies development manager Craig Rothleitner, Curtin researcher Dr Zahanggir Alam and research supervisors Associate Professor Anna Heitz, Associate Professor Faisal Anwar and Dr Dipok Sarker.

Dr Alam said the CBI has the potential to be used as the primary treatment component of water-sensitive urban designs, but further research was needed to explore this.

“While this research focuses on the removal of nutrients from stormwater now, it can be further developed to also remove heavy metals, hydrocarbons and other environmentally harmful dissolvable pollutants,” he said. “This will be the focus of our research moving forward.”

Dr Alam received a Curtin University Chancellor’s Commendation for his work, awarded to research doctoral students who submitted outstanding theses, judged to be in the top 10% of theses examined for that year, and considered to have made a significant contribution to the field of knowledge.

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