Destilador solar do tipo cascata com o uso de materiais fototérmicos aplicado no tratamento de águas superficiais

Abstract

Water intended for human consumption must be potable and comply with the established physicochemical, microbiological, and radiological standards to prevent health risks. Solar distillation is a process that resembles the natural hydrological cycle of water, consisting of two main stages: evaporation and condensation. This study aimed to evaluate the incorporation of photothermal materials (gravel and marbles) into a solar distillation system to achieve efficient and economically viable water production, microorganism inactivation, and cost analysis of distilled water production. The adopted methodology involved introducing these materials into the distillers, allowing them to absorb solar radiation and consequently increase water temperature. Physicochemical and bacteriological tests were conducted before and after the distillation process to determine the presence or absence of microorganisms. The system was fed with contaminated water collected from the Bodocongó reservoir, located in Campina Grande, PB, Brazil. The results demonstrated that the use of photothermal materials significantly increased the temperature inside the distillers, presenting higher values compared to systems without these materials. To validate the recorded temperatures, thermal images of the system were captured, confirming that the distillers containing gravel and marbles reached temperatures of 70.0 °C and 69.5 °C, respectively, while the distiller without photothermal material reached 69.3 °C. The productivity of distilled water increased by 16% in the distiller with gravel and by 3% in the system with marbles, compared to conventional distillers. The efficiency rates of the distillers containing photothermal materials were considered satisfactory, reaching 58.14% and 58.02%, respectively, at the end of the daily operation cycle. It is concluded that the use of photothermal materials proved effective in removing salts and microorganisms from the water. Therefore, the development and implementation of solar distillers enhanced with these materials represent a viable, sustainable, and cost-effective alternative. The estimated water production cost was R$ 0.14 per liter, highlighting the applicability of this technology to meet the needs of isolated communities, where water demand is moderate and solar radiation incidence is high, contributing to health promotion and well being in vulnerable populations.