Researchers look at improving solar disinfection of water

Solar disinfection of water — or SODIS — essentially involves putting water in plastic bottles and exposing them to sunlight for six hours, using the sun’s natural thermal and UV effects to kill contaminants. 

With a few basic deployment guidelines, it is highly effective and as such is used regularly by approximately 4.5 million people in the developing world and is promoted by the World Health Organization (WHO).

Nevertheless, as project lead Dr Anthony Byrne of Ulster noted, the simplicity of the approach also leaves it open to flaws.

‘The effectiveness of the process is dependent on a number of environmental parameters such as latitude, time of day, atmospheric conditions, the initial water quality, turbidity, level, and nature of the bacterial contamination… and you’ve no indication if the process has actually been effective,’ he told The Engineer.

Byrne’s team has been working for 10 years on ways of improving the process and scaling it up with simple reactors for households or small communities. Specifically, it has been looking at how various nanoparticles might augment SODIS through a process called photocatalysis.