Collaborative Research: Photocatalytic Chemistry of Low Solubility Phosphate Colloids in Environmental Aquatic Mixtures.

Purdue University, West Lafayette IN

Investigators

Abstract

With this award, the Environmental Chemical Sciences Program in the Division of Chemistry funds Professor Alexander Laskin at Purdue University and Professor Jonas Baltrusaitis at Lehigh University and their graduate and undergraduate students. Struvite, a common wastewater valorization product, contains essential plant nutrients, phosphorus and nitrogen. Utilized as a fertilizer, its low solubility microcrystals exhibit slow-release properties, providing a gradual nutrient release in line with plant uptake rates. Because of the unique composition of struvite and typically present iron impurities, struvite can catalyze environmental chemistry reactions, facilitating the transformation and remediation of organic pollutants and dissolved organic matter (DOM). This project will advance fundamental environmental chemistry knowledge concerning the under-studied colloidal struvite-organic mixtures, which in turn will be transformative to advance broader research on the complex multi-phase environmental aquatic mixtures. It will lay the foundation for the fundamental understanding of processes underlying practical use of the environmentally friendly slow-release struvite fertilizers. The broader impact of the project extends to providing quantitative predictions of the composition and physical properties of struvite microcrystals, a common wastewater valorization product, and their its environmental impact when used as a fertilizer. Project results will inform decisions regarding engineering, process design, and management controls for practical utilization of environmentally friendly struvite fertilizers, enhancing their performance and value, while aligning with the needs of environmental protection and sustainability. The interdisciplinary nature of this project creates a unique educational opportunity for students, offering hands-on experience with advanced synthesis techniques and state-of-the-art analytical methodologies. This experimental project investigates the chemical composition, physical properties, and catalytic behavior of laboratory-synthesized struvite with varying and tailored iron content. Given struvite's potential to serve as a sustainable alternative to conventional fertilizers and mitigate environmental issues such as water eutrophication and tropospheric pollution, this project fills critical knowledge gaps necessary for a predictive understanding of struvite's environmental implications. The project will investigate the chemical transformations of representative laboratory proxies of DOM catalyzed by synthesized struvite colloids with varying iron content. These experiments will yield fundamental insights into the multiphase reaction chemistry of struvite microcrystals and their impact on DOM in aquatic environments. Ultimately, this research will delineate struvite’s role in the complex multi-phase chemistry of terrestrial and atmospheric water systems. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.