A new automated solar disc for water disinfection by pasteurization.

A new automated Solar Water Pasteurization Disc of double reflection of 3.8 and 1.3 m in diameter for the first and second reflectors has been erected and tested for performing microbiological disinfection of water in a simple, efficient, and continuous treatment in Brazil. The disc was constructed with a light weight aluminum frame and low-cost materials such as iron and small mirrors of 10 × 10 cm for easy assembly and replacement. The solar disc is automated for solar azimuth tracking and free of any connection to the electrical network. Experiments were conducted in summer and autumn with an average solar radiation of 150 W m-2, and the solar disc achieved a water flow of 60 litres per hour at temperatures above 60 °C. The water showed 100% disinfection effectiveness in tests with Escherichia coli. Therefore, this solar disc produces 315 litres of safe water between 10:00 and 15:00 h in the Brazilian Southeast. The solar disc's low relative weight, portability, and lack of connection to the electricity grid and production of drinking water for one family per day make it possible to consider its use in rural areas that are poor and difficult to access.