CAREER: A Bottom Up pAproach Toward Understanding the Sunlight Driven Mechanisms and Pathways for the Release of Metals from Petroleum.

University Of New Orleans, New Orleans LA

Investigators

Abstract

With support from the Environmental Chemical Sciences Program in the Division of Chemistry and the Established Program to Stimulate Competitive Research (EPSCoR), Phoebe Zito in the Department of Chemistry at the University of New Orleans will study how sunlight changes petroleum-bound metals and their impact on ecosystem health. As a result of the sun's energy, pollutants on the surface of the earth can be broken down. Even though the oil is invisible once it has been cleaned up, it can still have detrimental effects on aquatic health. Sunburned oil produces compounds that are water-soluble and can mobilize through the water. Several of these compounds contain heavy metals which are frequently found in petroleum mixtures. Research is necessary on heavy metal reactivity and fate, as well as heavy metal effects on aquatic life. The energy in sunlight can break down petroleum, but very little is known about the resulting materials. Project data will show how sunlight helps release the metals from the petroleum and how their transformations affect the natural biogeochemical cycle. The research will be complemented by education and outreach activities aimed at diverse students. Activities will introduce students to potential STEM (science, technology, engineering and mathematics) careers, including in industry. This will be accomplished through a collaboration with a local nonprofit organization. Under this award, petroporphyrins will be exposed to simulated sunlight. Experiments will assess both physical and chemical changes that occur. Metal concentrations will be determined using inductively coupled plasma triple quadrupole mass spectrometry (ICP-MS). Phototransformation pathways will be determined in the petroporphyrin and water layer using electron paramagnetic spectroscopy and chemical probe methods. Studies in the presence of humic and fulvic acids will be undertaken to evaluate the impacts of petroleum bound metals (PBMs) on colloidal stability, complexation and their role in biogeochemical cycling. Photoredox transformations of PBM-soil interactions will dictate their bioavailability in aquatic environments. The size of metals will be determined using single particle ICP-MS, dynamic light scattering spectrophotometer and electron microscopy. 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.