Arsenic and other minerals have been removed from river water using solar power by a team of Peruvian and Chilean researchers.
Researchers from Peru’s National Engineering University and Chile’s Tarapacá University have photochemically purified water from the river Locumba near Tacna, a Peruvian town by the border with Chile.
The decontaminated water is used for agricultural irrigation, though depending on the level of decontamination achieved it could be used for human consumption in future.
The technology’s ease of use means it could be used in the countries involved with the research as well as Bolivia; Andean countries where natural contamination is present in many waterways.
Juan Rodríguez, coordinator of the research in Peru, told SciDev.Net that the technology is able to reduce high levels of arsenic contamination of currently 500 parts per billion (ppb) to about 30 ppb.
The researchers designed prototypes of electrochemical equipment and decontamination filters for use in rural or difficult to access areas, which for the moment can treat 20 cubic metres of water daily.
“Modular systems can process much higher volumes, so that’s what we’re trying to achieve,” Rodríguez said.
They used a photochemical system with tubes of glass or plastic to decontaminate the water. Based on reflections the tubes get solar radiation for a few hours, which can purify water contaminated with arsenic and make it suitable for consumption.
This system can also decontaminate boron and iron from water, as sunlight accelerates the rate at which minerals coagulate and can then be removed.
According to Rodríguez, this research is of importance for Bolivia, Chile and Peru because “the problem of arsenic in waterways is of natural origin and doesn’t distinguish between borders”.
Translation kindly provided by Cobi Smith.