Phosphogypsum Waste Recycled as Road Materials

MOUND MUSEUM LECTURE SERIES SPOTLIGHTS

Topic
The phosphate fertilizer industry, while integral to agriculture, continues to produce staggering amounts of phosphogypsum (PG), an acidic and hazardous waste byproduct concentrated with heavy metals, radionuclides, and other toxic elements.

Although the disposal of PG in the US has been regulated in engineered stacks for nearly four decades due to the potentially harmful emission of radon, multiple factors associated with its accumulation have suggested it is no longer a sustainable solution for PG disposal. In search of a more viable solution, alternatives such as recycling PG are being researched across the world.

One promising approach explores the reuse of PG as a road construction material. With approximately 9 million lane miles of public roads in the US, incorporating PG into future road construction could serve as a long-term solution to not only dwindle the current storage, but also recycle the future production of PG.

The EPA has approved a small-scale pilot PG-based road study in Florida. This paper examines the possibility of the future implementation of PG-based roads nationwide across the US. This research has studied state-specific regulations, site-specific environmental implications, best practices for future use, and long-term performance of PG-based roads to compare and complement the current pilot approval and navigate future practical hurdles industry may encounter as they incorporate PG into US road systems.

Speaker’s Biography
Catesby Mallard is a master’s student in the University of Alabama at Birmingham’s (UAB) Health Physics program in her final semester. She currently works as the UAB’s Health Physics Lab manager and has had experience researching the development of radiopharmaceuticals and as a health and safety specialist with Environmental Health and Safety.

Time: Log-on Apr 29, 2026 between 6:30 PM – 6:55 PM EST (Log-on closes at 7:00 PM when talk begins)
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For additional details on this presentation call 937-353-4457. The presentation is free and open to the public and has ample free parking.

Mound Cold War Discovery Center
E-Mail: msem475@gmail.com
Phone: 937-247-0402
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