PVA/biowaste-derived substances electrospun fibres: a promising sustainable tool for pollutant removal

Water supply is an issue of major concern, since safe hydric resources are not accessible to a large part of the global population. In order to provide solutions to the pollution criticality, many depuration methodologies have been adopted [1]: a particular attention has been paid to the exploitation of innovative materials in tertiary water treatments, which provide a final depuration stage before water is reused, recycled or discharged into the environment. In this framework, we prepared fibres of Polyvinyl alcohol (PVA) and biowaste-derived substances isolated from green compost (BBS-GC) by electrospinning technique. PVA is a non-toxic, biodegradable and biocompatible polymer with good film-forming ability due to the abundance of hydroxyl groups able in establishing intermolecular hydrogen bonding [2]. BBS-GC are water-soluble macromolecules with a complex lignin-derived structure containing acid and basic functional groups bonded to aromatic and aliphatic chains [1]. Although PVA has been widely employed to form fibres by electrospinning method [3], for the first time we blended it with BBS-GC. Such electrospun materials were prepared by using different ratios between the two macromolecules and, then, thermally treated in order to favour the condensation reaction between PVA hydroxyl groups and BBS-GC carboxylic groups. We observed fibres with diameters in the submicron range by scanning electron microscopy and we studied the physicochemical features by thermogravimetric analysis and infrared spectroscopy. Lastly, we applied such fibres in preliminary adsorption trials towards a cationic dye and caffeine as model pollutants.