Ensuring safe and high-water quality water remains a critical global challenge as conventional treatments fail to remove persistent micropollutants. Nanobubble (NB) technology has emerged as a sustainable upgrade for wastewater treatment plants due to unique properties like exceptional stability and high gas transfer efficiency. This systematic bibliometric review addresses knowledge fragmentation by synthesizing 1669 publications from 1999 to 2025, providing a comprehensive 25-year perspective on the field. The analysis reveals a clear research trajectory shifting from fundamental interfacial characterization (1999-2010) to diversified wastewater applications (2016-2025). Principal component analysis confirms this evolution, with 77% of data variance capture by NB dynamics and specialized applications such as advanced oxidation, flotation, and anaerobic digestion. Crucially, this study highlights that NB implementation can effectively reduce aeration energy consumption in full-scale industrial wastewater treatment applications, primarily in dissolved air flotation systems, depending on system design and baseline technology, directly supporting cleaner production goals. However, challenges persist regarding the standardization of generation methods and the scaling of processes within complex industrial/urban wastewater matrices. By identifying emerging hotspots and underexplored domains, this work provides a data-driven roadmap for researchers and policymakers to facilitate the transition from laboratory proof of concepts to full-scale sustainable implementation. • Bibliometric analysis of 1669 studies on nanobubble applications in wastewater treatments. • Evolution from fundamental nanobubble properties to process-driven applications. • Nanobubble dynamics and applications dominate recent research trends. • Nanobubble technology is application-ready but faces generation and scale-up challenges.
Nieto et al. (Fri,) studied this question.