Fate of micro- and nanoplastics in water bodies: A critical review of current challenges, the next generation of advanced treatment techniques and removal mechanisms with a special focus on stormwater

Micro- and nanoplastics (MNPs) are a growing source of pollution from natural and plastic fibers to non-fiber particles in water matrices. The current review highlights the detection, pathways, measurements and fate of MNPs. Besides, it addresses various treatment technologies, the next generation of MNPs degradation and their removal mechanisms from water bodies especially stormwater. The removal efficiency of MNPs decreases with decreasing particle size, as smaller particles were able to pass more easily through the tertiary sand filter or membrane filter. NPs exhibited lower removal efficiency compared to MPs. Conventional methods for treating stormwater including bioretention filters and constructed wetlands are inadequate in removing MNPs effectively. Some novel methods, such as egg protein derived ultra-lightweight hybrid monolithic aerogel, rely solely on gravity and do not require water, demonstrating up to 100 % removal of microplastics from seawater. This method could also be applied to stormwater treatment. This is superior to membrane technologies including UF and MF, which operates with a substantial energy input and excess water. Integrated treatment systems that combine different technologies can overcome the limitations of individual methods. Furthermore, the core mechanisms involved in eliminating MPs/NPs via biofilm consist of electrostatic surface attachment, hydrophobic interaction, absorption onto the biofilm layer, intermolecular repulsion, and electrostatic interaction between MPs/NPs and the membrane surface. • Bioretention filters and constructed wetlands are not effective in removing MNPs. • A rapid sand filter is more effective than granular activated carbon for MPs. • MNPs can be removed by adsorbing onto the fouling layer in membrane processes. • MPs deteriorated short-term and long-term nanofiltration membrane fouling. • Charge neutralization, adsorption, and sweep flocculation are dominant mechanisms involved in removing MNPs from stormwater.