From humid air to clean water: new innovation in sustainability


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Cacti inspired a recent study on water condensation, with potential implications for water-stressed areas around the world (flickr).

Julia Poska | January 10, 2019

Ohio State University researchers believe clean drinking water can be harnessed from nighttime air, when water is more prone to condensing. They have been developing methods for capture with the aid of some unusual experts: desert lifeforms.

The pointy tips and sharp spines on cacti collect water from nighttime fog and funnel it town to the plants roots. Desert grasses do the same with pointed blades.  Beetles collect water on their backs, which feature water-repellant and water-attracting spots that push the water towards the bugs’ mouths. These features help the plants and insects survive in harsh, low-water conditions.

The researchers, led by Bharat Bhushan, professor of mechanical engineering at Ohio State, have been experimenting with materials, shapes and textures using 3D printed models in foggy enclosures. They have already determined that conical shapes and grooved textures are efficient water collection methods and hope to test prototypes in deserts outside the lab as they continue to develop designs. They published their findings so far in Philosophical Transactions of the Royal Society in late December.

The final products of their work could have implications for water-scarce areas, where strife over clean water will only worsen with climate change. Water captured by such devices could supplement the drinking water supplies of private homes or whole communities.

“Water supply is a critically important issue, especially for people of the most arid parts of the world,” Bhushan said in a Science Daily report. “By using bio-inspired technologies, we can help address the challenge of providing clean water to people around the globe, in as efficient a way as possible.”

Climate Assessment predicts water stress on multiple levels for U.S.


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This graphic from the Fourth National Climate Assessment shows groundwater depletion in U.S. aquifers a decade ago. Today, these underground water supplies are even more depleted. 

Julia Poska| November 30, 2018

We already know climate change is having major impacts on rainfall. The 2018 Iowa Climate Statement said the strongest rainfall events of the year may double in intensity by 2025.  Climate change will alter the hydrologic cycle in other ways as well, majorly changing society’s relationship with water.

The Fourth National Climate Assessment, controversially released Black Friday, details the forecasted changes to water supplies in the U.S.. It compiles the findings of over 300 experts and has been reviewed by 13 federal agencies, in an effort to inform top decision-makers and common citizens.

More intense rainfall will be met with more intense drought and reduced snowpack, which is bad news for communities that rely on glacial melt for their water supply. These changes are exacerbating water availability issues caused primarily by overuse of groundwater aquifers in much of the U.S..

As higher temperatures create even higher demand for water for drinking and irrigation, this problem will only get worse and worse, which will have major implications for both the food supply and the industrial sector.

The altered hydrologic cycle will impact the quality of our limited quantity of water as well. Rising water temperatures will impact the health of ecosystems, and changes  runoff patterns of pollutants into water will impact human health and pose challenges for water treatment facilities. Sea level rise could also threaten coastal drinking water supplies with the potential intrusion of saltwater flooding.

The report says the biggest water issues for the Midwest are adapting stormwater management systems and managing harmful algae blooms. Iowa is already familiar with floods produced by intense rainfall.  Algae blooms, fueled by nutrient-runoff from farm fields, will be further increased by rising temperatures.

Other water-related challenges detailed in the assessment include the deterioration of water infrastructure and managing water more strategically in the future.