A simple glass plate coated in a common mineral can kill all the bacteria in contaminated well water in just ten minutes of sunlight.
Solar disinfection is a lifesaver in developing countries, but usually takes six hours and does not always kill everything. This new method uses a cheap titanium dioxide coating that acts as a catalyst when hit by UV rays. In field tests in Madagascar, it achieved total inactivation of fecal coliforms nearly sixty times faster than the standard method. The coating is non-uniform and easy to apply to basic glass plates, making it extremely accessible for low-resource settings. This turns a slow, unreliable process into a near-instant way to get safe drinking water. It has the potential to save millions of lives by making clean water reachable for everyone.
Solar photocatalytic disinfection of well water using immobilized TiO2: A comparative field study with SODIS in Antananarivo
arXiv · 2605.04089
Access to safe drinking water remains a major challenge in rural areas of developing countries. This study investigates the feasibility of a simple, low-cost solar photocatalytic reactor coated with commercial titanium dioxide (TiO$_2$) for the disinfection of well water contaminated with fecal coliforms. A TiO$_2$ film was deposited on a glass plate using a straightforward acetone slurry method and exposed to natural sunlight in Antananarivo, Madagascar. The efficiency was compared to the conve