Eco-friendly recovery of cellulose acetate from combusted cigarette filters and reuse for membrane fabrication

Cigarette filters, widely discarded and slow to degrade, represent a significant source of environmental pollution. This study presents a novel eco-friendly protocol for recovering cellulose acetate (CA) from smoked cigarette butts using a solvent-based solubilization–desolubilization method with acetic acid as the green solvent. The novelty of this approach lies in its ability to extract and purify CA under mild conditions while avoiding toxic solvents and multi-step processing, commonly found in previous methods. The recovered cellulose acetate (RCA) was thoroughly characterised using FTIR, TGA, DSC, XRD, and mechanical testing, confirming its chemical and physical equivalence to commercial-grade CA. To validate the functional performance of the recycled material, RCA was repurposed into membranes and tested in a proof-of-concept study for water remediation. These preliminary tests involved the adsorption of methylene blue (MB), with removal efficiencies reaching 55.1 ± 4.8 %, and up to 92.0 ± 13.7 % upon surface modification with TiO₂ under solar lamp irradiation. While not the central focus of this work, the membrane experiments serve to confirm the applicability of RCA in established cellulose acetate use cases. Overall, this work highlights a scalable and sustainable strategy for converting cigarette filter waste into valuable polymeric materials, supporting circular economy principles and offering an alternative to conventional CA recovery processes.