Nanobubble (NB) technology has been explored in water treatment, yet comprehensive evaluations of its full-scale implementation remain limited. This review aims to examine the NB technology’s potential to enhance performance and its full-scale deployment status and future applications in water treatment. The review begins with a summary of the NB fundamental science to support deeper understanding the NB technology. It then discusses key NB technology research gaps pertinent to full-scale implementation, including: treatment mechanisms under realistic conditions, reliable methods for post-application NB characterisation, performance advantages at full-scale, and long-term impact/fate of NBs in environmental systems. Comprehensive analysis of pilot- and full-scale trials in this review highlights that environmental water restoration, supplemental wastewater aeration, and NB-assisted dissolved air flotation are the most advanced NB applications in water treatment. Importantly, while NB technology shows promise in improving treatment efficiency at the research level, its scale-up and potential full-scale adoption remain in early stages; therefore, its process economics are still unclear. Addressing these challenges requires long-term pilot/full-scale techno-economic assessment studies to establish NB technology as a viable solution for water treatment.
