Turning Air into Drinking Water: Can This Technology Quench People's Thirst?

Image is for visualization purpose only GEMINI

A World Running Dry

Access to clean, fresh water is a fundamental human right, yet it's a right denied to millions across the globe. The statistics paint a grim picture: nearly 770 million people that's one in ten people on the planet lack access to safe drinking water. In many regions, the burden of water collection falls disproportionately on women and girls, who often spend hours each day trekking long distances to haul heavy containers of water.

India, with its burgeoning population and limited freshwater resources, faces a particularly acute water crisis. Major cities are teetering on the brink of "Day Zero," a terrifying scenario where taps run dry. Mismanagement and pollution have rendered many traditional water sources unusable, while groundwater is being depleted at an alarming rate. Climate change further exacerbates the situation, with deforestation and changing weather patterns contributing to water scarcity. The 2018 Composite Water Management Index (CWMI) report by NITI Aayog paints a stark picture: 600 million Indians face high to extreme water stress, and an estimated 200,000 people die each year due to inadequate access to safe water. By 2030, the country's water demand is projected to outstrip supply by twofold, threatening severe scarcity and potentially impacting India's GDP.

A Solution in the Air We Breathe?

As traditional water sources dwindle, the need for alternative solutions becomes increasingly urgent. One promising avenue is atmospheric water generation (AWG), a technology that literally pulls water from thin air. Even in the driest climates, the atmosphere contains a surprising amount of water vapor. AWG technologies capture this vapor and condense it into liquid water, offering a potentially revolutionary solution to water scarcity. The Earth's atmosphere holds an estimated 12,900 cubic kilometers of water, and this amount is predicted to increase in the coming decades. Even in Chile's Atacama Desert, one of the driest places on Earth, fog and dew can generate a significant amount of water. This highlights the vast potential of AWG to tap into an abundant and renewable resource.

How Does AWG Work?

Several methods are used to extract water from the air:

• Desiccant materials: substances like silica gel absorb water vapor from the air. The material is then heated to release the vapor, which is condensed into liquid water.
• Active air cooling: Similar to how air conditioners work, this method cools the air below its dew point, causing water vapor to condense.

Innovations on the Horizon

Scientists and engineers are constantly pushing the boundaries of AWG technology. Promising new approaches include:

• Thermo-responsive hydrophilicity switching (TRHS): This technique uses special materials that change their affinity for water in response to temperature fluctuations. At low temperatures, the material absorbs water vapor, and at high temperatures, it releases the water in liquid form.
• Deliquescent salt reverse osmosis (DESARO): This method employs deliquescent salts, which readily absorb moisture from the air. The resulting salt solution is passed through a reverse osmosis membrane to separate the water from the salt.

World map showing the preferred local water-from-air technology. Image reproduced with permission from (R. Peeters, et al., Fresh water production from atmospheric air: Technology and innovation outlook, iScience, 24, 103266, 2021. https://www.sciencedirect.com/science/article/pii/...)

Companies Pioneering AWG Technology
Across the globe, companies are developing and deploying AWG solutions:

• Global Leaders:
  • Watergen: An Israeli company specializing in large-scale AWG systems, often used in disaster relief and to provide drinking water in remote areas.
  • Sky water Technology: A US-based company offering a range of AWG solutions for residential, commercial, and industrial use.
  • Eole Water: A French company focusing on wind-powered AWG systems, promoting sustainable water solutions with minimal environmental impact.
• Indian Innovators:
  • Airowater: An Indian company providing energy-efficient and affordable AWG purifiers for homes and offices.
  • Maithri Aquatech: A startup developing solar-powered AWG systems to address water scarcity in off-grid, rural communities.
  • Uravu Labs: A startup specializing in sustainable and energy-efficient AWG solutions, utilizing renewable energy sources and innovative materials.

References & Suggested Reading

• R. Peeters, et al., Fresh water production from atmospheric air: Technology and innovation outlook, iScience, 24, 103266, 2021. https://www.sciencedirect.com/science/article/pii/S2589004221012359
• The Indian Startup Pulling Water From the Air Uravu’s new 1,000-liter-per-day unit will come on line this month. https://spectrum.ieee.org/water-harvesting
• Innovative air-to-water tech using liquid desiccant makes affordable, renewable water. https://india.mongabay.com/2024/08/innovative-air-to-water-tech-using-liquid-desiccant-makes-affordable-renewable-water/
• Turning air into water: The essential parts of air-to-water technology. https://a1rwater.com/featured/essential-parts-of-air-to-water-technology/
• Water to the people: a pathway through innovative technology and public-private partnerships. https://www.weforum.org/agenda/2024/02/atmospheric...