A new anti-fatberg invention could help unclog city sewers.

RMIT Engineers have developed a coating for concrete pipes aimed at reducing the formation of fatbergs, which contribute to costly sewer blockages. 

Fatbergs are caused by the solidification of fat, oil, and grease (FOG) mixed with calcium and water within sewer systems.

The new invention, a zinc-enhanced polyurethane coating, has been shown to decrease calcium release by 80 per cent and FOG build-up by 30 per cent in laboratory simulations. 

The study, led by Dr Biplob Pramanik, Director of the Water: Effective Technologies and Tools (WETT) Research Centre, used extreme conditions to replicate sewer environments and speed up fatberg formation over a 30-day period. 

FOG-induced blockages are a significant issue in urban sewer systems, accounting for 40% of blockages in Australia and 50% in the United States. 

The financial toll is substantial, with an annual cost of AU$100 million in Australia and US$25 billion in the United States for maintenance and repairs.

Dr Pramanik says traditional coatings, such as magnesium hydroxide, are effective against corrosion but can exacerbate FOG accumulation by interacting with fatty acids.

“The reduction of fat, oil and grease build-up can be attributed to the significantly reduced release of calcium from coated concrete, as well as less sticking of FOG on the coating surface compared to the rough, uncoated concrete surface,” he explained.

The new coating is stable in water, heat-resistant up to 850°C, and self-healing at room temperature. 

Inspired by the regenerative abilities of human skin, the team demonstrated the coating’s self-repair capabilities by deliberately scratching its surface and observing improvement over time. 

The research team plans to refine the coating further to enhance its FOG-reduction effectiveness and mechanical strength. 

Dr Pramanik is also leading an ARC Linkage Project to develop advanced grease interceptors for food service establishments, addressing FOG issues upstream in sewer systems.

The ARC Linkage Project involves partnerships with key stakeholders, including South East Water, VicWater, Barwon Region Water Corporation, and Queensland Urban Utilities, alongside water technology company ACO. 

More details are accessible here.