A microbiologist from Stellenbosch University (SU), Dr Wesaal Khan, is part of an international consortium of specialists that have been tasked to develop a range of sustainable solar disinfection (SODIS) technologies that will provide affordable access to safe drinking water to remote and vulnerable communities.

Dr Khan, who heads the water resources laboratory in the Department of Microbiology at SU, will focus on the use of SODIS systems to treat rainwater harvested on household and community level.

"South Africans living in the rural areas are familiar with the concept of rainwater harvesting. But while communities in the Eastern Cape can routinely use the rainwater for drinking purposes, our research shows that that is not the case in especially urban areas," she explains.

Rainwater in these areas become contaminated with heavy metals due to air pollution. The debris of plants and faecal matter from birds and small animals also tend to collect on roofs and then pollute the rainwater harvested from these roofs with microorganisms.

Dr Khan warns that the disease-causing microorganisms isolated from rainwater tanks during their trials are associated with a number of diseases, such as diarrhoea, pneumonia and worm infestations, amongst others.

She says the aim of the project, called WATERSPOUTT, is to upscale and develop new large-scale solar disinfection technologies. WATERSPOUTT is the acronym for 'water sustainable point-of-use treatment technologies'.

The ideal is to design a system that will produce sufficient quantities of treated per day so that it can be used in both household and community settings, such as schools and clinics.

"The idea is to supplement municipal services, supplying drinkable water, with the rainwater harvesting technologies so that people can use the rainwater for domestic activities such as washing the dishes, laundry and personal hygiene," she adds.

Based on 30 years of research, SODIS is one of the simplest and most cost-effective water treatment technologies currently available. It uses the combined effect of ultraviolet radiation and the heat from sunlight to inactivate the whole spectrum of microbes and even bacteria such as Vibrio cholerae and protozoa such as Cryptosporidium. Thus far, however, it has only been used for small quantities of water for domestic use.

The project is funded by the European Union's Horizon 2020 programme and is led by Prof. Kevin McGuigan from the Royal College of Surgeons in Ireland. He has been involved with SODIS research for more than 20 years and pioneered the use and promotion of the two litre bottle SODIS technology.