Performance Evaluation of a Solar Still for Brackish and Sulfurous Treatment toward Potable and Agricultural Applications

Abstract Brackish and sulfurous groundwater, which naturally flows and emerges in the form of springs in the hajlan Valle area, with the primary aim of assessing the quality of the distilled water relative to the World Health Organization (WHO) potable water standards. Experimental trials were conducted across four different seasons, with each experiment repeated four times and an experimental error margin of ±0.1. In each trial, the basin of the solar still was filled with 35 liters of untreated water. The recorded distilled water yields were 5.5 L in winter, 6.9 L in spring (with comparable purity), 9.8 L in summer, and 5.8 L in autumn. Pre-treatment water samples contained 14 mg/L of chloride and 500 mg/L of sulfates, with an electrical conductivity of 5.8 DC. After treatment, these values were reduced to 0.2 mg/L (chloride), 10 mg/L (sulfates), and 0.2 DC for conductivity, indicating that the treated water complied with potable water quality criteria The results highlight the significant potential of solar stills in producing potable water, thereby contributing to sustainable regional development. However, several operational challenges persist, most notably the fouling of the glass surface, which can substantially hinder long-term system performance. Furthermore, the seasonal impact of winter—marked by reduced daylight hours—may be mitigated through the integration of a solar water heater to elevate the temperature and preheat the feedwater prior to its entry into the solar distillation unit.