The University of Miami is advancing sustainable construction research through a partnership with the Miami-Dade County Water and Sewer Department and major cement manufacturers, including Titan and Cemex. Led by Ali Ghahremaninezhad, associate professor of civil and architectural engineering, the team is investigating how lime sludge—a byproduct of municipal water treatment—can be used in concrete materials.
“This project reimagines lime sludge as a resource rather than waste,” Ghahremaninezhad said. “Incorporating lime sludge into concrete offers a dual benefit: addressing environmental waste from water treatment plants while reducing the carbon footprint of construction materials.”
Lime sludge, a chalky byproduct generated during drinking water purification, has long been a disposal challenge for municipalities, often ending up in landfills or requiring costly removal. The research seeks to repurpose this material in ways that meet construction standards.
The process begins with treating drinking water, during which calcium hydroxide—known as lime—is used to remove impurities. Researchers have found that lime sludge has a chemical composition similar to some materials used in cement. By carefully processing the sludge and blending it with other ingredients, Ghahremaninezhad’s team aims to replace a portion of traditional cement in concrete. This substitution reduces reliance on energy-intensive cement production, thereby cutting carbon dioxide emissions.
The collaboration underscores the importance of multidisciplinary approaches to addressing climate challenges, bringing together experts from academia, local government, and industry leaders.
As the research advances, the potential to transform concrete production could lead to widespread adoption of lime sludge-enhanced materials. The findings may further reduce the environmental impact of one of the world’s most widely used materials, paving the way for more sustainable infrastructure development.
