RUI: Fundamental Investigation Towards Phosphorus Recovery Through Organophosphate Pesticide Degradation by Molybdate Complexes

This project is funded by the Environmental Chemical Sciences Program of the Chemistry Division. Pesticides and herbicides are used to kill weeds and insects, but these chemicals last a long time and can be found throughout the environment. These chemicals can be damaging to animals and humans, and have even been implicated in neurodegenerative diseases. Using basic chemistry techniques, this project from Professor Louis Kuo at Lewis and Clark College looks for ways to make these pesticides and herbicides safer. A main ingredient in these chemicals is the element phosphorus. This project also investigates the use of non-toxic metals to collect, break down, safely recover, and transform the phosphate-based toxins for a new use. Phosphorus is non-renewable and essential for life on earth, so recycling it is important for sustainability. This research lies at the interface of inorganic and organic chemistry, and uses a combination of experimental and computational techniques. Undergraduate researchers, high school students, and high school teachers participate in this project, while engaging in meaningful science within the context of safe environmental stewardship.<br/><br/>This research project addresses environmental toxin remediation and phosphorus recovery. Organophosphates (OP) are agricultural pesticides that are now ubiquitous in the environment. As such, there is a need for materials that degrade these OP pesticides in a practical fashion. This goal is more meaningful when the degraded OP pesticides are recovered as usable organophosphates since phosphorus is an essential but non-renewable resource. This study focuses on using supported and solution=-phase molybdenum complexes that convert organophosphate toxins into commodity chemicals. Specifically, the project examines how polystyrene-supported and picolinato (solution) complexes of molybdenum-peroxo compounds convert sulfur-containing organophosphate pesticides and the widely-used glyphosate herbicide (Roundup) into phosphate commodity chemicals. Several hypothetical routes involving reactive oxygen species are tested with spectroscopic studies on solution models and supported molybdenum-peroxo complexes. In parallel with the experimental work there is a computational component using density functional theory that simulates the organophosphate reactions. The goal is to predict and design better molybdenum complexes that accomplish the organophosphate degradation. In this connection, the long term goal is to develop new supported and practical molybdenum-peroxo materials that degrade the organophosphate toxins into value-added materials.<br/><br/>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.