Advances in microbubble-based separation technologies for microplastics removal from water

The widespread occurrence of microplastics (MPs) in aquatic environments has raised significant ecological concerns, particularly due to their interactions with coexisting pollutants and potential impact on aquatic ecosystems. Microbubble (MB) flotation has emerged as a low-cost, scalable solution, achieving removal efficiencies of 75–95 % for MPs (50–5000 µm) through tailored bubble size (10– 100 µm) and surface charge optimization. This review systematically examines the physicochemical properties of MPs, their role as pollutant carriers, and recent advancements in CFD-guided MB generation techniques, including the effects of MP aging and aquatic chemistry on separation performance. By synthesizing experimental and computational studies, we highlight how CFD modeling has uncovered critical mechanisms-such as turbulent flow regimes and bubble- MP collision probabilities-that enhance capture efficiency. Furthermore, we discuss innovations in pulsatile flow MB systems and surfactant-free stabilization strategies. This work identifies key gaps in CFD-MB integration, such as multiscale MP heterogeneity and biofilm interactions, and proposes adaptive modeling frameworks to address them. By bridging experimental insights with computational advances, this review summarizes the advantages and limitations of MB-enhanced MP separation and provides the perspective on potential applications after further improvements.