The potential risks posed by micro-nanoplastics to the safety of disinfected drinking water

Micro-nanoplastics (M-NPs) have become an emerging critical issue in the environment because they migrate easily, can bioaccumulate with toxic effects, and are difficult to degrade. Unfortunately, the current technologies for removing or degrading M-NPs in drinking water are insufficient to eliminate them completely, and residual M-NPs in drinking water may pose a threat to human health by impairing human immunity and metabolism. In addition to their intrinsic toxic effects, M-NPs may be even more harmful after drinking water disinfection than before disinfection. Herein, this paper comprehensively summarizes the negative impacts of several commonly used disinfection processes (ozone, chlorine, and UV) on M-NPs. Moreover, the potential leaching of dissolved organics from M-NPs and the production of disinfection byproducts during the disinfection process are discussed in detail. Moreover, due to the diversity and complexity of M-NPs, their adverse effects may exceed those of conventional organics (e.g., antibiotics, pharmaceuticals, and algae) after the disinfection process. Finally, we propose enhanced conventional drinking water treatment processes (e.g., enhanced coagulation, air flotation, advanced adsorbents, and membrane technologies), detection of residual M-NPs, and biotoxicological assessment as promising and ecofriendly candidates to efficiently remove M-NPs and avoid the release of secondary hazards. [Display omitted] •M-NPs can threaten drinking water safety by releasing DOM or DBPs in disinfection.•The potential risks of M-NPs to UV and ozone disinfection are easily overlooked.•The risks of different types of M-NPs in disinfection should be further evaluated.•Some strategies are proposed to better address these potential hazards.