Original Authors: Rachid Safoui, Rachida Belaaribi, Omar Achahour, Abdeslam Elfanaoui, Ahmed Ihlal, Ammar Mouaky, Mohamed El Habib Amagour, Hicham Abou Oualid, Mohamed M Awad
Water scarcity continues to pose significant challenges globally, prompting the exploration of innovative methods to harness fresh water from unconventional sources. Among these, atmospheric water harvesting (AWH) presents a viable solution, especially for remote and arid regions. This essay explores a promising approach using a desiccant-based solar still, focusing on experimental investigation and economic analysis conducted under specific climatic conditions in Agadir, Morocco.
System Design and Methodology
The core of the system is a solar still integrated with a desiccant material, specifically river sand impregnated with calcium chloride (CaCl2), known for its high hygroscopic properties. The experimental setup included a single-basin solar still where the desiccant bed captures water vapor at night and releases it during the day under solar heating, thus completing the cycle of water vapor absorption and desorption. This process was observed over consecutive days to assess the stability and effectiveness of the water harvesting system.
Experimental Findings
The study detailed in the paper revealed that the system could consistently capture and condense water vapor, achieving an average water production rate of 0.604 liters per square meter per day. Notably, the desiccant bed managed to harvest 671.02 ml/m² of water vapor at an average ambient temperature of 25 °C and 80% relative humidity, demonstrating the feasibility of using locally available materials like river sand and CaCl2 in water-scarce environments.
Economic Viability
An in-depth economic analysis highlighted the cost-effectiveness of the desiccant-based solar still, with water production costs estimated at $0.086 per liter and a payback period of 18.25 months. These figures are particularly compelling when compared to more traditional water supply methods like desalination, which typically have higher operational and initial setup costs.
Conclusion
The desiccant-based solar still examined in the study offers a sustainable and economically viable solution for water scarcity issues in arid regions. By leveraging simple yet effective technology and locally available materials, such systems can be implemented to provide a continuous supply of fresh water with minimal environmental impact. Future research could explore enhancements in desiccant materials and system designs to further increase water yield and efficiency, making atmospheric water harvesting a cornerstone of sustainable development in water-stressed regions.
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