SBIR Phase I: Plastic Waste Oxidation to Soil Carbon Amendments

The broader impact of this SBIR Phase I project will be to recycle certain plastics into soil amendments to improve both environmental degradation and agricultural health. Plastic waste is a persistent environmental pollutant partly due to the lack of comprehensive technologies to reduce the in-circulation inventory of these petrochemical products, and comparably low value of plastic-derived and recycled products. The carbon contained within mixed plastic waste represents both a significant pollutant, but also a potentially valuable alternative feedstock for domestic agriculture and regenerating degraded soils. Soil carbon is a key driver in building soil health, agricultural productivity and food security, as well as a significant reservoir for long-term carbon sequestration. This project remediates traditionally non-recyclable, low-value mixed plastic waste and transforms it into a high value compost-like material. The proposed research develops a low-cost, distributed, decentralized process suitable for small, remote, rural, marginalized and underrepresented communities to achieve sustainable, domestic solid waste management as well as build and regenerate soil health for self-sufficient local agriculture. This SBIR Phase I project will scale and optimize a plastic oxidation process that employs a novel high efficiency intramolecular modification of Fenton oxidation. The aqueous process utilizes a low-cost, green catalyst that does not require high temperatures or organic solvents to cleave and oxidize a wide range of commercial polymers into bioavailable long-chain fatty acids suitable as a soil microbe substrate and soil organic carbon amendment. Compared to the highly variable process of natural biodegradation, this reaction ensures complete remediation before environmental application through controlled chemical oxidation. This research will aim to characterize this novel process towards a scalable technoeconomic model to guide translation at scale. Methods include near-infrared spectroscopy to track the elimination of microplastics and other toxic components common to plastic waste processing. The plastic-derived, environmentally beneficial soil amendments will be further studied in greenhouse and field trials to evaluate key agronomic indicators, such as amendment-microbe interactions, soil health, productivity and others. 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.