Eradicating microplastics in wastewater: microalgae as a sustainable strategy

Microplastics (MPs) are pervasive environmental pollutants that have infiltrated ecosystems worldwide due to their small size and persistence. Although wastewater treatment plants (WWTPs) can achieve up to 90 % removal of MPs, this is insufficient to halt their continuous accumulation in the environment. Microalgae offer a promising and sustainable alternative for mitigating MPs pollution, as they can remove MPs from wastewater (WW) through various mechanisms. This manuscript reviews the application of microalgae in WWTPs for MPs removal, exploring the properties of MPs, their pathways through different stages of WWTPs, and the potential of microalgae for MPs sequestration. It also examines the interactions between microalgae and MPs, highlighting the environmental and operational factors that influence removal efficiency. While laboratory-scale studies showcase significant promises, real-scale applications remain underexplored, particularly regarding economic feasibility and scalability. Notably, microalgae may require extended retention times to capture MPs efficiently, posing a practical challenge. By critically assessing the advantages, limitations, and outlook of microalgae-based WW treatment, this work reviews their potential as a transformative and sustainable strategy for the remediation of MPs.