Innovative techniques harness the sun and mimic nature’s ingenuity for efficient desalination
Amidst growing global concerns about water scarcity and the environmental impact of traditional desalination methods, a team of researchers at Khalifa University has investigated the intricate mechanism of halophyte plants, invented a mangrove-mimicked solar distillation device, presenting a comprehensive model that integrates capillary pumping and evaporation processes for passive solar desalination. Prof. TieJun Zhang led the team on both projects, comprising Muhammad Sajjad, Mohamed Abdelsalam, Dr. Aikifa Raza and Dr. Faisal AlMarzooqi.
Their device not only efficiently produces fresh water from seawater but also manages brine without discharging it into the environment, addressing significant ecological issues associated with salt buildup in natural water bodies. These results were published in.
The “Freshwater Generator” was designed to mimic the natural water management of mangroves, using a foldable structure with “leaves” and “stems” made from a titanium mesh covered with nanostructured titanium dioxide. This design enhances sunlight absorption and water transport, maximizing the efficiency of solar distillation. The mangrove-like structure supports passive, capillary-driven water transport and selective salt crystallization at the leaf edges, which prevents salt accumulation on the main evaporative surface and maintains high operational efficiency.
The team proposed a novel capillary transport model that precisely describes the passive saline water supply through synthetic porous wicks and evaporation at the synthetic leaf designed for solar desalination. Understanding wicking behavior with varying water saturation levels across the porous synthetic stem is crucial for enhancing our understanding of how saline water is pumped up against gravity without external driving force and evaporates in synthetic and real mangroves. These results were published in the.
The insights gained from this study are invaluable for designing next-generation solar desalination systems and mark a significant step towards a sustainable future in water resource management.
The team’s freshwater generator achieves an efficiency of about 94 percent and can produce up to 2.2 liters/m2 of fresh water per day from seawater. Its efficiency stems from its design, allowing for continuous operation by naturally shedding salt buildup overnight, preparing the system for operation the next day without manual cleaning. Overall, the simple design and portable nature of their solar-driven freshwater generator can provide a viable solution to produce clean water in remote areas. Using solar energy for passive desalination actually eliminates both the carbon footprint and pumping costs, and the zero-brine discharge with salt collection also prevents potential ecological damage typically associated with high-salinity waste from traditional desalination plants.
Jade Sterling
Science Writer
27 May 2024
