Engineers have developed a new protective layer for concrete pipes that could significantly lessen the occurrence of fatbergs in sewage systems.
Engineers from RMIT University have developed a new protective layer for concrete pipes that could significantly lessen the occurrence of fatbergs in sewage systems.
Fat, oil, and grease (commonly referred to as FOG) are notorious for hardening within pipes and concrete sewers. They are responsible for around half of all sewage backups in the United States and 40% in Australia. The financial burden of these blockages for maintenance and repairs is estimated to reach US$25 billion in the US and A$100 million in Australia annually.
The combination of fat, oil, and grease with calcium and water found in sewers often results in the creation of fatbergs. However, a zinc-infused polyurethane coating from the engineering team shows great promise as a sustainable solution by minimizing the amount of calcium released from concrete by as much as 80% in comparison to untreated concrete.
The research led by Dr. Biplob Pramanik simulated sewer conditions under extreme measures that accelerated fatberg formation within a 30-day period.
The findings indicated that the coating diminished the accumulation of FOG on concrete surfaces by 30% when compared to untreated concrete.
“The decrease in fat, oil, and grease accumulation can be credited to the significantly lower calcium release from the coated concrete, along with a reduced adherence of FOG on the coated surface relative to the rough, uncoated concrete,” stated Pramanik, who directs the Water: Effective Technologies and Tools (WETT) Research Centre at RMIT.
“Conventional coatings like magnesium hydroxide have been utilized for over 20 years to prevent sewer corrosion but can unintentionally lead to FOG buildup by interacting with fatty acids.”
The innovative coating developed by the team performs well in water and can endure temperatures up to 850 degrees Celsius. Additionally, it possesses self-healing properties at room temperature, allowing it to repair damage on its own and prolong its lifespan.
“We took inspiration from nature’s regenerative properties, such as the human skin’s healing abilities,” Pramanik noted.
Co-researcher Dr. Sachin Yadav explained that the team tested the healing effectiveness of the coatings by making surface scratches with a blade.
“Introducing surface scratches on the self-healing polyurethane coating prompted the healing process,” Yadav said.
“After the healing period, we noticed a significant improvement in the scratched areas.”
Future Directions
The team is working on a more advanced coating to achieve an even greater decrease in FOG deposition in sewers by improving its self-healing features and mechanical durability.
Pramanik is also the Chief Investigator for a newly launched ARC Linkage Project that aims to create an advanced grease trap for restaurants and food service providers, enhancing the removal of small FOG particles more effectively than existing technologies.
His RMIT team is collaborating with South East Water, VicWater, Water Research Australia, Barwon Region Water Corporation, Queensland Urban Utilities, and the water tech firm ACO on the ARC Linkage Project.
The study titled “Novel hybrid coating material with triple distinct healing bond for fat oil and grease deposition control in the sewer system” appears in the Chemical Engineering Journal.
