A technique developed by researchers at the University of São Paulo's school of agriculture could help Brazilians obtain purified water at low cost and using less energy. Instead of electricity, the process uses solar and ultraviolet radiation to evaporate the water, which is then condensed in a system cooled by natural gas to distill it to the degree required for chemical analysis.

In addition to saving energy, it uses all of the water volume, compared to current methods, in which 48 liters are needed to produce one purified liter. The cost reduces by a factor of 30 the 280 reais (150 dollars) needed today to produce one cubic meter of purified water.

“Although it is insufficient for industrial use, the technology can be adapted, reducing costs and environmental impacts, with significant results,” project coordinator Marcos Kamogawa told Tierramérica.