Current status of using adsorbent nanomaterials for removing microplastics from water supply systems: a mini review

The widespread use of plastic has led to microplastics (MPs) being released in many water sources. MP contamination in water supply systems is a global concern due to their persistence and ability to adsorb toxic pollutants. Despite having effectiveness, conventional water treatment processes still have limited efficiency in removing MPs, especially smaller particles. Thus, it requires researchers to develop effective and sustainable strategies to deal with this matter. Many studies have shown that adsorbent nanomaterials have potential for the removal of MPs from water. This review evaluates the current status of using adsorbent nanomaterials in removing MPs from water supply systems. It discusses the occurrences and removal efficiency of MPs in water supply systems, as well as the mechanisms and performance when applying these materials for treatment. In addition, the related risk of adsorbent nanomaterials is also considered. Microplastics from land-based sources and wastewater plants persist in water supplies, with conventional treatments removing only 40-70%, especially struggling with smaller particles. Based mainly on mechanisms like electrostatic interactions, hydrophobic interactions, pore filling, hydrogen bonding, π-π stacking, and surface complexation, adsorbent nanomaterials achieve over 90% removal of MPs and can recovery. Their effectiveness depends on material properties and environmental factors, but challenges remain in scale-up and related risks. Adsorbent nanomaterials show promising potential to enhance MP removal through specific properties. Although some related risks are discussed, these materials provide a foundation for developing sustainable, effective solutions to mitigate MPs pollution in the water supply system.