Rapid industrialization, urban expansion, and rising energy demand have intensified global environmental challenges, including pollution and resource depletion. Nanomaterials and nanofluids have emerged as promising solutions due to their unique physicochemical properties and tunable surface characteristics, which enhance contaminant removal, catalytic activity, and thermal and mass transfer performance compared with conventional materials. This review provides a comprehensive overview of nanomaterial and nanofluid–based technologies, highlighting key findings from recent research and their effectiveness across various environmental applications. While wastewater treatment remains a primary focus, applications in heat transfer, energy systems, and biomedicine are also discussed to illustrate transferable mechanisms, performance principles, and design strategies relevant to environmental technologies. Despite their potential, challenges persist in large‐scale implementation, long‐term stability, nanoparticle (NP) recovery, and environmental safety. Future research should prioritize sustainable deployment, recovery strategies, and life‐cycle assessments (LCAs) to maximize the environmental and practical benefits of nanomaterials and nanofluids.
Nour et al. (Thu,) studied this question.