Alkaline aging significantly affects Mn(II) adsorption capacity of polypropylene microplastics in water environments: Critical roles of natural organic matter and colloidal particles.

Most microplastic particles may undergo various aging in water environments. In this work, surface physicochemical properties were firstly compared among pristine polypropylene (PP-pris) microplastics, and two aged ones obtained after pretreated with HCl (PP-acid) and NaOH (PP-alka). When compared with PP-pris and PP-acid, PP-alka had a much stronger Mn(II) adsorption capacity.