Abstract:Inadequate access to purify water and sanitation requires new ergonomic methods at lower cost, less energy consumption, minimal use of chemicals and impact on the environment. Among them ultrasound is a unique means to control physics and chemistry of complex fluid (wastewater) with excellent performance in mass transfer, cleaning and disinfection. In membrane filtration processes it overcomes diffusion limits and can accelerate the fluid flow towards the filter preventing antifouling. Here we outline the current state of knowledge and technological design with the focus on physico-chemical strategies of ultrasound for water cleaning. We highlight important parameters of ultrasound for the delivery of fluid flow from a technical perspective employing principles of physics and chemistry. By introducing various ultrasonic methods involving bubbles or cavitation in combination with external fields we show advancements in flow acceleration and mass transportation to the filter. In most of them we emphasize the main role of streaming and impact of cavitation with a perspective to prevent and remove fouling deposits during the flow. We also elaborate on the deficiencies of present technology and on problems to be solved to achieve a wide spread application.