Principle and applications of microbubble and nanobubble technology for water treatment

In recent years, microbubble and nanobubble technologies have drawn great attention due to their wide applications in many fields of science and technology, such as water treatment, biomedical engineering, and nanomaterials. In this paper, we discuss the physics, methods of generation of microbubbles (MBs) and nanobubbles (NBs), while production of free radicals from MBs and NBs are reviewed with the focuses on degradation of toxic compounds, water disinfection, and cleaning/defouling of solid surfaces including membrane. Due to their ability to produce free radicals, it can be expected that the future prospects of MBs and NBs will be immense and yet more to be explored.

► We review the potential application of micro and nanobubbles for water treatment.
► The physics and generation methods of micro and nanobubbles are discussed.
► The production of free radicals by the collapse of microbubbles is reviewed.
► Micro and nanobubbles for water disinfection, degradation of organic compounds and defouling are highlighted.
► Micro and nanobubbles technology appears to be a cost-effective and environmentally friendly approach for water treatment.