Upcycling textile derived microplastics waste collected from washer and dryers to carbonaceous products using hydrothermal carbonization

Abstract

Microplastics are an emerging pollutant of concern. Many microplastics in the waters arise from washing synthetic textiles in residential and commercial washing machines. The present research evaluated the upcycling of this waste to carbon materials by hydrothermal carbonization. Real microfiber waste was collected using clothes washer and dryer microfilters. Via temperature and residence time screening (200 °C, 250 °C, 300 °C and 1 h, 4 h, 8 h) two temperatures of interest were determined (250 °C and 300 °C) for hydrothermal carbonization, for a residence time of 4 h. The results obtained in this research demonstrated that by varying the reaction conditions carbon production can be tailored, producing amorphous carbon or graphene/graphite. To this end, Raman spectroscopy results indicated the production of carbon nanomaterials; smaller particle sizes were detected after 250 °C-4h and 300 °C-4h treatments, (29.6 nm and 33.1 nm, respectively). Transforming microfibers into useful carbon nanoparticles via hydrothermal carbonization prolongs their lifecycle and mitigates environmental pollution. This process is an intriguing method of incorporating textile residue (microfibers) into the circular economy, where resources are perpetually recycled, and waste is avoided.