Antipathogenic upcycling of face mask waste into separation materials using green solvents

Abstract

The use of disposable face masks has considerably contributed toward waste generation, particularly during the current COVID-19 pandemic. Little attention has been dedicated to the actual examination of recycling strategies for increasing the life cycle of this biomedical waste, as the most common treatment for disposing used masks is incineration. In this study, we screened green solvents for the recycling of face masks by taking advantage of their antipathogenic nature for sterilization purposes. This work is timely and unique because it presents for the first time the successful recovery of polypropylene from face masks, and upcycle of the masks into either a microbead or free-standing membranes as separation materials. Owing to their excellent chemical stability, the membranes are well-suited for organic solvent nanofiltration. The fabricated membranes exhibited molecular weight cut-off values between 665 and 964 g mol−1, which were fine-tuned by adjusting the coagulation bath temperature from 20 °C to 60 °C. The membranes demonstrated long-term stability over 5 days of continuous filtration at 30 bar, with rejection values exceeding 98% for roxithromycin and rose bengal. This scalable methodology for upcycling used face masks into high-value products has the potential to reduce a crucial environmental threat associated with the global rapid growth of the face mask market.