In a significant breakthrough for sustainable construction practices, researchers have explored the potential of using phosphogypsum (PG) and contaminated sediment as subgrade materials in pavement construction. The study, led by Dragana Tomašević Pilipović from the Department of Chemistry, Biochemistry and Environmental Protection at the University of Novi Sad, highlights an innovative approach to addressing two pressing environmental issues: the management of hazardous waste and the demand for sustainable construction materials.
Phosphogypsum, a by-product of phosphoric acid production, presents both an environmental challenge and an opportunity. For every ton of phosphoric acid produced, 4–5 tons of PG are generated, leading to significant waste accumulation. Meanwhile, polluted sediments in aquatic environments pose long-term risks due to their heavy metal content, which can adversely affect ecosystems and human health. The study aims to tackle these challenges by investigating the use of PG as a stabilizing agent for contaminated sediments, ultimately transforming waste into valuable construction material.
Pilipović explains, “Our research demonstrates that incorporating phosphogypsum into sediment mixtures not only aids in immobilizing heavy metals but also enhances their mechanical properties, making them suitable for subgrade applications.” The findings reveal that mixtures containing 3% and 5% phosphogypsum showed promising California Bearing Ratio (CBR) values—12.5% and 22.9%, respectively—indicating potential viability for use in road construction.
The implications of this research are profound for the construction sector. As industries increasingly seek sustainable alternatives to traditional materials, utilizing PG and contaminated sediments could reduce the environmental footprint of construction projects while addressing waste management challenges. The study also emphasizes the need for further optimization of phosphogypsum content to meet strength requirements, suggesting a pathway for continuous improvement in material performance.
The research methodology included long-term leaching tests, uniaxial compressive strength tests, and detailed chemical analyses, ensuring a comprehensive understanding of the mixtures’ properties. Results indicated that while the uniaxial compressive strength did not yet meet the minimum requirements for road construction, the overall benefits of using these treated sediments are substantial. “The leaching tests showed minimal pollutant release, affirming the potential for safe utilization of PG and sediment,” Pilipović noted.
As the construction industry grapples with the dual pressures of sustainability and regulatory compliance, this study, published in ‘Applied Sciences’, offers a viable solution that could reshape material sourcing and waste management practices. By transforming waste into resources, the research not only contributes to environmental remediation but also opens new avenues for commercial development in the construction sector.
For more information on this pioneering work, visit the Department of Chemistry, Biochemistry and Environmental Protection at the University of Novi Sad.