Besides being an available natural resource, the solar energy is very applicable in places with few recourses and low money resources, because there aren't either the need of chemical products neither a huge cost (commercial materials can be reused). To make this job we re-used PET bottles half painted black with the variables: 1, 2, 4 and 6 hours of heat exposion and we also used a concentrator of rays of sunshine. The affluent control parameters were turbidity, apparent color, temperature, total coliforms and E. coli. These last three were evaluated before and after the desinfection process (effluent parameters). To assess the bacteria reactivation we kept the water in bottles for 24 hours, pretending a very common situation in Brazilian rural houses. We conclude that the use of the concentrator of rays of sunshine can reduce the heat exposion from 6 to 4 hours, without harm the SODIS efficience. Using the concentrator of rays of sunshine for 6 hours we can obtain, besides SODIS, the process of solar pasteurization (SOPAS), which stops the re-growth of bacteria with a 70ºC water temperature. We also observed that when the sky is cloudy the incidention of solar radiation and, therefore, the SODIS efficience decrease, even if the water temperature is higher during the desinfection. Although, this factor doesn't mean a significative influence statistically.
Water treatment; water quality; technological alternatives; rural sanitation
