Micro and nanobubble technologies as a new horizon for water-treatment techniques: A review

This review article organizes the studies conducted on the areas of microbubbles and nanobubbles with a special emphasis on water treatment. The basic definitions of bubble types and their size ranges are also presented based on the explanations of different researchers. The characterization parameters with state-of-the-art measuring and analysis techniques of microbubble and nanobubble technologies are summarized. Some major applications of these technologies in water-treatment processes are reviewed and briefly discussed. Based on the reviews, various potential areas for research and bubble application gaps in water and wastewater treatment technologies are identified for further study. The article is prepared in such a way that it provides a step-by-step acquaintance to the subject matter with the objective of focusing on the application of microbubbles and nanobubbles in water-treatment technology.