Adsorption properties of natural and synthetic fiber microplastics for organic dyes: Effects of aging and environmental factors

The surge demand for disposable plastics items around the world not only led to a sharp consumption in natural and petroleum resources but laid a heavy burden on environmental waste management, due to their inevitable fragmentation and potentially as a source of microplastics (MPs). Regrettably, their environmental behavior still lack sufficient understanding. This study aims to investigate the ultraviolet (UV) aging of disposable face towels, an emerging kind of disposable plastics items, made of regenerated cellulose (RC) or polyethylene terephthalate (PET), and its vector effect in aquatic environment. The variation and influences of surface physicochemical characteristics, including its surface charge and hydrophilic properties, type of dye pollutants and environmental factors, especially the salinity, on their interactions were comparatively characterized or explored. The results indicated that hydrogen bonding primarily governed the interactions of RC-MPs and dyes with electrostatic interaction involving, while the interactions of PET-MPs and dyes were predominantly driven by electrostatic attraction. Environmental factor analysis revealed that disposable face towels tends to associate readily with various pollutants in aquatic environments, particularly in marine ecosystems. This research provides important insights into the environmental behavior and fate of MPs released from disposable face towels.