In regions such as Peru, Bolivia, Chile, Morocco, and Oman, where fog envelops the landscape, ingenious solutions have emerged to tackle water scarcity. Among these is the practice of erecting nets that capture water droplets from the mist, providing a lifeline for drinking, cooking, and hygiene. This innovative approach, known as fog collection, has the potential to yield hundreds of liters of water daily from just a few square meters of netting. However, a daunting challenge accompanies this promising method: atmospheric pollution, which contaminates the gathered droplets, rendering them unfit for consumption or daily use.
In a groundbreaking endeavor, a team led by ETH Zurich scientists has pioneered an unprecedented solution that addresses both water harvesting and purification. Their approach entails a meticulously designed lattice of metal wire, coated with a blend of carefully chosen polymers and titanium dioxide. These elements work in tandem to revolutionize the fog collection process.
The polymers are adept at efficient droplet accumulation on the mesh, allowing them to swiftly cascade into a container before wind interference occurs. Meanwhile, the titanium dioxide functions as a chemical catalyst, breaking down the organic pollutants inherent in the droplets and neutralizing their harmful properties.
Remarkably, this novel system not only captures fog-induced water but also treats it, making it applicable even in locales marked by atmospheric pollution, such as densely populated urban centers. Lead author Ritwick Ghosh, a scientist from the Max Planck Institute for Polymer Research, emphasized the innovation’s significance, highlighting its ability to address multifaceted challenges.
Intriguingly, the method’s operational demands are minimal. With little to no maintenance required, it solely relies on regular doses of UV light to rejuvenate the catalyst. A mere half-hour of sunlight suffices to reactivate the titanium dioxide, a particularly valuable feature in areas plagued by scarcity of sunlight, typical of fog-prone regions.
Laboratory and pilot plant tests in Zurich substantiated the efficacy of this paradigm-shifting fog collector. The system successfully accumulated eight percent of artificially generated fog water and disintegrated a remarkable 94 percent of introduced organic compounds, including minute diesel droplets and hormonally active chemicals like bisphenol A.
Beyond providing potable water from fog, this trailblazing technology also offers potential for recovering water used in cooling towers. This would prevent steam from escaping into the atmosphere, especially in contexts like the United States, where extensive freshwater consumption for power plant cooling is prevalent.
As the senior author, Thomas Schutzius, a professor of Mechanical Engineering at the University of California, Berkeley, and formerly associated with ETH Zurich, points out, capturing such water before it dissipates holds promise for environmental conservation and purity maintenance.
Looking ahead, the researchers intend to refine their approach further, exploring its untapped potential to alleviate water scarcity challenges for countless individuals across afflicted areas. The study, published in Nature Sustainability, underscores the transformative impact of innovative thinking and underscores the crucial role of science in shaping a sustainable future.
Fog collection is not a new concept; it has been employed in various corners of the globe, especially where freshwater sources are scarce. By leveraging vast mesh installations, water droplets suspended in fog are captured, merged, and collected for various applications. While the technique offers sustainability and efficiency, its yield can fluctuate based on fog intensity and frequency. Although it might not single-handedly quench the thirst of large communities, it serves as a supplementary solution. Ranging from supporting local communities in the arid Atacama Desert to providing supplementary irrigation in agriculture and aiding reforestation efforts, fog collection showcases the remarkable potential of tapping into nature’s resources.