Testing water purification products and water testing systems in off-grid communities

  • Hajime Shinohara (Physics (Winton Scholar), PhD, 2nd
  • Mike Coto (Materials Science and Metallurgy, PhD 3rd

One of the most urgent problems facing off-grid communities is lack of clean drinking water. Globally approximately 2000 people die every day due to lack of access to clean water. Companies and NGOs have tried to purify water in off-grid communities all over the world. However, purification approaches have proved successful in some places but not in others as local and regional variations in the nature of water contamination demand different filtration, neutralisation and disinfection technologies.

Various types of water purification solutions are available. The main types are: physical filtration, UV purification and chemical additives. Each type addresses some water quality problems but not others. For instance, filters can be effective for microbes but ineffective for toxic chemicals such as arsenic, which occurs naturally in water in countries such as Nepal and India. Disinfection methods utilising UV lights effectively kill bacteria but are ineffective for toxic materials. Chemical additives may effective for some toxic materials but unable to remove harmful chemicals.

Moreover, although effective purification methods exist, in the case of many off-grid communities it is possible either that such methods have not reached these communities, or that the water purification approaches used are not ideal for their particular circumstances. Therefore a systematic assessment of the suitability of particular purification methods in specific off-grid communities would be beneficial.

A further challenge is created by the fact that water testing methods in some off-grid communities are often not scientifically reliable. While water quality seems poor, in many off-grid villages around the world true water quality is not clearly known. Though there are global criteria for drinking water standards from the World Health Organization, in some places water quality is assessed primarily through observation of its colour and transparency, and whether or not people drinking it become ill.

This project optimizes both the purification and testing of water in off-grid communities. After evaluating the effectiveness of current water quality assessment systems in each community, the Smart Villages team will suggest context-appropriate, low-cost water purification approaches, and will test the results using a range of context-appropriate, low-cost water testing methods.

Team members will check the water purity before and after using each approach or product alone and in combination. The data produced will be analysed in collaboration with Dr. Vasant Kumar’s water purification research group in the Department of Materials Science and Metallurgy at the University of Cambridge. Members will establish connections with local NGOs who will continue measurements of water purity in the areas visited by the team in Nepal and India.

The project is supported by the Humanitarian Centre, which is facilitating access to off-grid communities in Nepal and India through its member organisations and local partners. The Humanitarian Centre is supporting the team further by making water testing the focus of one of the projects undertaken during the Humanitarian Centre’s Development i-Teams initiative in May.

The results of the project will be written up in two types of reports: a general report that will be published on the Smart Villages and Humanitarian Centre websites, along with those of in-country host NGOs and communities; and a technical report for the organizations involved in the project and the Materials Science water purity research group.