Recycling Contaminated Plastics Using Bioprocesses

December 14, 2020

Conventional recycling is underperforming globally in dealing with plastic waste.

Most plastics arrive at conventional recycling facilities contaminated with food, dirt and debris, and other materials that cannot easily be separated. Products made from these contaminated materials are lower in quality, a phenomenon known as “downcycling.” Chemical recycling approaches to recover the pure building block chemicals and produce brand new plastics could be a game changer, but these processes are typically too energy intensive. In response to this challenge, researchers at UMass Lowell are harnessing the power of enzymes to lower the cost and carbon footprint of this promising new approach.

Researchers have recently discovered organisms that can rapidly degrade PET plastic, whose use is on the rise in single-use packaging applications, topping 30 megatonnes annually. While some PET (recycling type #1) is already successfully recycled to produce new beverage bottles, 50% of all PET produced is in the form of textiles, sheet, and mixed materials, not suitable for mechanical recycling.

Funded by a $1.5M grant from the Department of Energy, Professor Meg Sobkowicz-Kline, along with colleagues Dongming Xie and Hsi-Wu Wong (UMass Lowell Chemical Engineering Department), is working to optimize this enzymatic recycling process for low quality contaminated PET sources and large-scale deployment. This bioprocess could help to replace the cradle-to-grave lifecycle of plastics and recover valuable resources from our waste.