SBIR Phase I: Bioreactors for Upcycling Pyrolyzed Polystyrene Waste into Organic Fertilizer

The broader/commercial impact of this Small Business Innovation Research (SBIR) Phase I project is to enable the recycling of common polystyrene foam waste into soil amendments: creating a valuable agricultural product out of a pernicious and ubiquitous waste. Annually, millions of pounds of polystyrene waste fill landfills, blot roadsides, or pollute waterways – making up 80% of all ocean plastic waste. Taking centuries to decompose, when finally broken down polystyrene may have terrible impacts on health. This project seeks to combine proven technologies with newly discovered abilities in microorganisms to digest polystyrene, to demonstrate a means by which polystyrene can be reconstituted into nutrient-rich material useful in agriculture. Because of the vast supply of polystyrene waste and the great commercial need to dispose of it, this project taps into a commercial potential not only to provide waste disposal services to a much underserved market but can do so while simultaneously producing a valuable agricultural good. This project supports the NSF’s mission by advancing the science of bioremediation, advancing the health and welfare of the nation by removing a harmful waste product from the environment, and supporting national prosperity by providing a much-needed service to a large industry. This project seeks to use a unique combination of technologies to demonstrate that polystyrene foam waste can be processed and bioremediated rapidly into a soil amending “castings” ready for use in gardening, farming, or landscaping. The project's research and development effort lies in the complex process of converting polystyrene from an unprocessed waste into both bioplastics and organic acids by way of thermal and biological methods, before further amelioration by decomposer organisms and the formation of a usable agricultural product. Bioreactors featuring numerous strains and species of microbes never-before deployed for this purpose will be used in tandem with macro-organisms whose capabilities for this application are likewise mostly or entirely unstudied. This research will uncover the specific abilities of numerous species to digest polystyrene waste at multiple scales and will evaluate several potential pathways through which the resulting digestate could be further processed. Large sample sizes, stepwise variances in conditions, and permutations of species’ combinations will be used to ensure statistical veracity. These methods, coupled with the use of cutting-edge analytical equipment, will ensure a high precision in results. 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.