Black hair and copper chips as waste-derived modifiers to improve solar desalination performance: A comprehensive 6E analysis

Water scarcity and rising energy demands call for sustainable freshwater production technologies. Solar desalination is a promising solution, though its performance is limited by low evaporation and condensation rates. In this context, the utilization of black hair as an eco-friendly waste hydrophilic photothermal material inside a solar still in order to enhance its evaporation and water transport rates was experimentally investigated for the first time. This modified still was also integrated with copper chips to enhance thermal characteristics inside the still. Additionally, the modified stills were also tested under the influence of external condensation using cool water. Four configurations, conventional solar still, black hair-modified, black hair with copper chips, black hair with an external condenser, and both materials with the external condenser, were experimentally tested and compared using a comprehensive 6E analysis (energy, exergy, economic, exergo-economic, exergo-environmental, and exergo-enviro-economic evaluations). The results indicate that the modified still, utilizing both materials with the external condenser, achieved the highest performance in daily freshwater yield and energy efficiency, with improvements of 103.1 % and 104.35 %, respectively. Yet, without the external condenser, the still modified with black hair and copper chips attained the maximum augmentation of the exergy efficiency and cost reduction by 93.5 % and 34.1 %, respectively, with higher environmental performance as well. In summary, the outcomes illustrate the promise of combining inexpensive waste materials with thermal management systems for augmenting solar desalination to achieve sustainable and cost-effective freshwater production.