Could harvesting air breathe life into MENA's water crisis?

A team of researchers from Shanghai Jiao Tong University in China have developed a solar-powered technology that can extract water from the air.

This innovative technology has the potential to provide drinking water to people residing in arid regions where water scarcity is a significant concern.

The research paper, published on December 5 in the journal Applied Physics Review, suggests that this technology can help extract water that is naturally present in the air, which could provide a daily water supply for drinking and other purposes such as domestic and industrial use.

Water-stressed region

Over 2.2 billion people are currently living in countries where water is scarce, with the Arab region one of the areas most affected by water scarcity. The United Nations estimates that approximately 3.5 million people die each year due to water-related diseases.

"More than 80% of the Arab world is made up of deserts, which receive a low total amount of annual rainfall, usually not exceeding 200 mm. This makes them among the world's driest regions. However, the atmosphere in these regions contains a lot of water content that has the potential to be collected and used"

As the Arab region is located in one of the sunniest places in the world and is also among the countries most in need of improved drinking water, the region's abundant solar energy can be exploited to help tackle the issue of water scarcity.

On August 16, the World Resources Institute (WRI) issued a report warning that the Middle East and North Africa region is among the areas most affected by water stress.

The report identified Bahrain, Cyprus, Kuwait, Lebanon, Oman, and Qatar as the five countries most exposed to water stress.

Egypt, Jordan, Libya, the Emirates, Palestine, Yemen, Algeria, Morocco, Saudi Arabia, Tunisia, and Iraq also fell among the 25 countries most exposed to water stress in the world.

The report's authors predict that by 2050, 100% of the region's population will be living under very high water stress.

Susanne Schmeier, a Professor of Water Governance and Management at the Delft Water Institute in the Netherlands, believes that several factors contribute to water stress, such as the uneven distribution of surface and groundwater resources, climate change that leads to droughts and floods, and inadequate infrastructure.

Poor management, water treatment, and distribution can also lead to unsustainable water usage. Schmeier explained that armed conflicts and migration can significantly worsen water stress levels, impacting water rights, access to water facilities, and natural resources that are essential for food security and livelihoods.

More than 80% of the Arab world is made up of deserts, which receive a low total amount of annual rainfall, usually not exceeding 200 mm. This makes them among the world's driest regions.

However, the atmosphere in these regions contains a lot of water content that has the potential to be collected and used.

But this desert may have wealth, as there is still a lot of water content in the atmospheric air, and the absorption-based atmospheric water collection device proposed in the study can concentrate the moisture water in the air and turn it into usable liquid water, according to co-author Xiang Chengjie, a post-doctoral researcher at the Institute of Refrigeration and Cryogenics at Shanghai Jiao Tong University in China.

Kitchen-made technique

Historically, researchers have faced challenges when injecting salt into hydrogels as high salt content reduces the swelling ability of the hydrogels due to the salting-out effect. This resulted in salt leakage and decreased water absorption capacity.

“In this study, an absorbent material in the form of a super-hygroscopic 'gel' was synthesised using plant salt derivatives and hygroscopic salts to achieve an unprecedentedly high salt injection, allowing us to attest that this 'hydro-gel' is capable of absorbing an unparalleled amount of water and retaining it, to obtain the highest return from harvesting water from the atmosphere using a water harvesting device,” explained Chengjie to The New Arab.

Chengjie adds that one kilogramme of dry gel can absorb 1.18 kilogrammes of water in arid weather environments and up to 6.4 kilogrammes in humid weather environments, and explained to The New Arab how the team produced the gel: “Like the chef who baked the first meringue, we created a magical cookie that differs from meringue in that it has a large number of holes designed to hold large amounts of water like a sponge which is called as adsorbent. The moisture water content is snatched from the atmospheric by the adsorbent cookie.”

With this technology, it is possible to heat the adsorbent cookie to desorb water content which could thus be condensed in a condenser, thereby drinkable water in the desert could be obtained.

He noted that this adsorbent cookie is easy to prepare, does not require specific tools, and can be made even in the home kitchen. The cost of large-scale preparation is no more than $15 one kilogramme.

Solar energy hub

According to a report released by the Global Energy Observatory in September of last year, the MENA region's top solar power producers are the UAE, Oman, Morocco, Egypt, and Jordan.

Professor Abdul Hamid Ahmed, a professor of Physical Geography at Mansoura University in Egypt, explained that the region's vast deserts, sunny weather, and unique geographical location make it an ideal location for solar energy production.

Several MENA countries, including Egypt, Morocco, Saudi Arabia, the UAE, and Jordan, have invested heavily in renewable energy, particularly solar energy projects.

Professor Abdul Hamid Ahmed, the co-author of the report believes that the Arab region is one of the most promising areas for implementing water-harvesting devices due to its hot and arid climate.

This technology could be especially beneficial for the millions of individuals who lack access to clean water and need a simple and easily operable alternative. 

"Although North Africa and the Middle East are very hot, the moisture content of the atmosphere is not low, and in these regions, the large temperature difference between day and night, and the relative humidity increases at night, which is very favourable for the adsorbent to absorb moisture, and the daytime temperature is high, which is easy to use solar energy to desorb the adsorbent to obtain fresh water," Professor Abdul Hamid Ahmed concluded.

Mohammed El-Said is the Science Editor at Daily News Egypt. His work has appeared in Science Magazine, Nature Middle East, Scientific American Arabic Edition, SciDev and other prominent regional and international media outlets

Follow him on Twitter: @MOHAMMED2SAID