PRIORITY project in action: Advances and future directions on remediation, recovery, and development of sustainable alternatives to plastic materials to combat microplastic pollution

Micro- and nanoplastics (MPs and NPs) remain a fragmented challenge across prevention, removal, and circular recovery strategies. At the second meeting of the COST Action PRIORITY – Plastics monitoRIng detectiOn RemedIaTion recoverY Working Group 5 (WG5, focused on Remediation, Recovery, and Sustainable Alternatives), bringing together over 550 researchers from 53 countries, participants consolidated advances and defined shared priorities. Reported progress spans: (i) removal — membrane trains, bubble barriers, and graphene-based aerogels enabling water flow with selective adsorption of sub-100 µm polymer particles; (ii) bio- routes — plastisphere-derived microbial consortia and an engineered whole-cell catalyst co-displaying polyethylene terephthalate (PET)- degrading enzymes PETase and MHETase for PET depolymerization to terephthalic acid (TPA) and ethylene glycol (EG); (iii) recovery and upcycling — image-guided quality control to reduce expandable polystyrene (EPS) production waste and a mild, aerobic photochemical protocol converting polystyrene to benzoic acid; and (iv) sustainable alternatives — closed-loop poly(lactic acid) (PLA) systems based on room-temperature ring-opening polymerization and catalytic alcoholysis to alkyl lactates, and bio-derived encapsulants (polysaccharides and candelilla-wax nanoparticles) for slow-release agro-inputs that avoid plastic residues. Cross-cutting needs include reference materials, performance metrics (capture thresholds, yields, life-cycle assessment), and alignment with standardization and regulatory pathways. The meeting advocates prevention at the source as the primary strategy, complemented by controllable recovery and evidence-based remediation. The roadmap outlined connects laboratory validation to field deployment and policy uptake, enabling robust, harmonized, and scalable solutions against plastic pollution.