Low-Cost Solar Still System with Concave Condensing Cover for the Distillation of Synthetic Water Polluted with Allura Red Dye

Solar distillation is a highly interesting process due to its utilization of one of Earth’s most abundant natural resources: solar energy. Recent research has delved into various geometries and modifications to enhance the efficiency of solar stills and optimize the solar energy capture in the basin. This work proposes a modification to the condensation cover, featuring a solar still design with a cylindrical basin and a concave condensation cover, where distillate collection occurs in the lower central part of the basin. The study evaluated two construction materials for the cylindrical basin, namely stainless steel, and aluminum with Teflon coating, in the distillation of synthetic polluted water (distilled water with Allura red dye at a concentration of 50 ppm). Experiments were conducted under the environmental conditions of Toluca, Mexico. Distinct variations in water and inner air temperatures were observed, attributed to the reduction in the total volume of the proposed solar still. Under optimal conditions, water temperatures reached a maximum range between 68 to 74 °C. The solar still with an aluminum basin featuring Teflon coating showed the highest efficiency in distilling Allura Red dye, as assessed by UV-Vis spectroscopy