Green-Synthesized Nanomaterials for Water Disinfection: Mechanisms, Efficacy, and Environmental Safety.

Safe drinking water is essential, yet millions of people remain exposed to contaminated supplies. Conventional treatments such as chlorination and UV light can kill microbes, but they also create harmful byproducts, face resistance issues, and are not always sustainable. Green-synthesized nanomaterials (GSNMs) are emerging as an eco-friendly alternative. Produced with plants, microbes, algae, and natural polymers, these materials merge nanotechnology with green chemistry. Among them, silver, zinc oxide, copper oxide, titanium dioxide, and graphene-based nanomaterials show strong antimicrobial effects by disrupting membranes, generating reactive oxygen species (ROS), and damaging genetic material. Compared with chemically made nanoparticles, GSNMs are often safer, cheaper, and more environmentally compatible. Nevertheless, concerns about toxicity, environmental fate, and large-scale use remain. This review highlights recent progress in GSNM synthesis, antimicrobial mechanisms, and safety considerations, highlighting their potential to enable sustainable water disinfection while identifying critical areas for further research.