Innovative methods for water disinfection

Title of the research project

Bubbles 4life: hydrodynamic cavitation for water disinfection in developing countries

Scientific area 


Project coordinator

Costantino Manes


Bubbles4life project developed a low cost robust and reliable method for water disinfection that can be used in developing countries, using a physical process called “Hydrodynamic Cavitation”.

Description of the research project

There are currently about 780 million people in the world who have no access to drinkable water sources. As a result of this, more than 3 million people die every year of sanitation and hygiene related issues and 99% of all deaths occur in developing countries. Such a water emergency is caused by several issues. Among these, the lack of appropriate water-treatment methods plays an important role. Technologies that are commonly and successfully used in the developed world cannot be used so easily in developing countries as they are associated with high costs of installation, maintenance and operation and they require the use of chemicals that are not easy to retrieve. The project tackles this issue by further developing a promising technique called Hydrodynamic Cavitation (HC). The technique relies on the principle of forcing water to flow in constricted regions and hence to make it boil as a consequence of the low-pressure levels it experiences. When pressure is restored, water bubbles implode violently generating conditions that are lethal for microorganisms. The current understanding of the physical processes governing water-treatment through HC is still very poor. However, Bubbles4life contributed to bridge this knowledge gap to design reliable and low-cost HC reactors. HC does not require chemicals and/or high-tech components, which makes it a perfect candidate for applications in developing countries.

Impact on society 

Sustainable supply of clean water can lead to an enormous drop in sanitation-related illnesses currently affecting developing countries. The results from bubbles4Life can also find numerous applications in high-income countries. For example, HC reactors applied in the food industry may promote water re-use (e.g., vegetables washing) and the reduction of chemicals for sterilization purposes, which may alter the properties and taste of food and drink-products. HC is also known to promote mixing and hence highly efficient HC reactors can be used to optimise chemical reactions occurring in liquids, which are of interest for a plethora of applications within the chemical and pharmacological industry.

Research results

Many experiments have been performed during the project to monitor sanitization efficiency while two parameters change: cavitation number and initial bacteria concentration. More generally, the project research group developed for the first time a theoretical framework for the study of Hydrodynamic Cavitation based on dimensional analysis and Bukingham theorem. This theoretical study males possible to scale up and design a high scale reactor.

Among the scientific results we highlight:

  • Two publications on peer reviewed  journals
  • A new project in collaboration with TREELIUM to develop an innovative cavitation device
  • Extended collaboration between the project coordinator and SMAT, a major Italian water utility company, serving Torino and the whole Piedmont region.

Short CV of project coordinator 

Costantino Manes graduated at the University of Ancona in 2002. PhD degree in Hydraulics in 2006 from the University of Aberdeen (Scotland, UK). Post doc in Switzerland at the institute for snow and avalanche research (2006-2008) and at the Polytechnic of Turin (2008-2011). Lecturer from 20011-2015 at the University of Southampton, UK. He has been Associate Professor of Hydraulics since 2015 at the Polytechnic of Turin. His main research interest spans from fundamental to applied Fluid Mechanics, with a clear focus on the study of turbulent flows. He is author and co-author of more than 40 publications in peer reviewed journals and proceedings of international conferences.

Working group@Polito

Luca Ridolfi, Full professor, DIATI

Riccardo Vesipa, DIATI

2  post Doc researchers


Academic Partner 

University of Southampton, United Kingdom

Non-academic Partner 

Società Metropolitana Acque Torino (SMAT)

  • Budget: 150.000 euro
  • Start date: 15/09/2017
  • End date: 14/09/2019