A new, eco-friendly substance created by engineers at the University of South Australia (UniSA) may lower the high maintenance expenses of Australia’s aging sewer system.
The invention combines powdered granulated blast-furnace slag, which is frequently used in the manufacturing of cement, with alum-based water treatment sludge, a waste product from the drinking water purification process.
According to a news release from the university, the final product is not only more than 50% stronger than conventional concrete, but it is also impervious to acid-induced deterioration, a major problem in sewage systems.
Because concrete is strong and reasonably priced, it is commonly used to build sewer lines. However, it is susceptible to corrosion from microbes and acids, which adds to the estimated $70 billion national repair and maintenance cost.
According to a study assessed in the Journal of Building Engineering, the recently created material might provide a more robust and economical option.
The research emphasizes a twofold benefit: enhancing sewer infrastructure and recycling a troublesome waste material, according to PhD candidate Weiwei Duan, whose work forms the basis of the study.
Sludge is typically dumped in landfills, which damages the environment by producing CO2 emissions during the waste’s transportation and reducing the amount of land accessible for other uses, according to Duan.
When compared to concrete constructed with 100% blast-furnace slag, the study’s tested samples with a 20–40% sludge percentage showed noticeably higher compressive strength.
Better resistance to sulfur-oxidizing bacteria, which are known to hasten corrosion in sewer conditions, was also demonstrated by the material.
According to lead researcher and principal supervisor Professor Yan Zhuge, the results suggest a viable substitute that supports both environmental and economic objectives.
According to Prof. Zhuge, “this has the potential to promote the reuse of water treatment byproducts, lower maintenance costs, and extend the service life of sewage pipes, thus contributing to the circular economy.”
“Reducing the need for cement will help to lower carbon emissions, as the construction industry is one of the largest emitters of greenhouse gases worldwide.”
As the first UniSA student to win the national award in 60 years, Duan’s efforts were recently acknowledged with the 2025 Australian Water Association’s Student Water Prize.
The research, titled Evaluating microbiologically influenced corrosion in alkali-activated materials incorporating alum sludge, was conducted by UniSA’s Professor Yan Zhuge, Weiwei Duan, Dr Yue Liu, Professor Christopher Chow, and Alexandra Keegan from SA Water Corporation.
Source : Australian Manufacturing
