While some desalinate sea water, others cause rain to fall and the last produce drinking water from ambient air, an overview of the latest technologies aimed at improving access to drinking water, a global issue.
In dry environments like desert countries, it is particularly difficult to find water. To produce it, some rely on the latest technologies. This is the case of scientists based in the United Arab Emirates who use innovation to make the rain fall.
They employ a weather modification technique called Cloud seeding, cloud seeding in French. An airplane is used to “seed” the clouds with hygroscopic salt particles. The sodium and potassium chlorides they contain attract the water droplets that are in the cloud. These droplets agglomerate to form larger drops which, being heavier, fall from the sky.
“Timing is very important in a cloud seeding operation because the pilots need to be in the cloud before it has matured so they can position themselves where the vertical wind is and so , succeed in the seeding operation,” says Ahmad al Kamali, weather forecaster at the Emirates National Meteorological Center (NCM).
Various international partners are working to develop and improve the effectiveness of this technique. “Enhancing rain production – or human intervention in the cloud through cloud seeding – can increase the amount of precipitation by 10-15% and under certain favorable conditions this can reach around 25% ,” says Sufian Farrah, Cloud Seeding expert at NCM. “It’s not nothing,” he adds. “Considering that each km³ contains about 500 tons of water, by spending an hour seeding clouds in the Emirates, you can make them generate a large amount of water, in a proportion of about 100,000 m³, “ he calculates.
Desalination of sea water
During the warmer months, the chances of seeing rain are slim. To ensure its supply of drinking water throughout the year, Dubai turns to its coastline.
More than 90% of the drinking water consumed in the emirate comes from the sea. Its large desalination plants can produce 200,000 m³ of drinking water per day.
“We take seawater and pass it through membranes,” describes Vanesa Fernández Membrillera, Sales and Management Manager for the Middle East ofO&M ACCIONA. “We obtain on one side, fresh water and on the other, slightly more salty sea water; we take fresh water and turn it into drinking water,” she continues.
“The main advantage of this process is that it is based on the fact that 98% of the water found on Earth is seawater,” she adds. “We have such a shortage of drinking water in some countries and their only source of drinking water is the sea,” she explains before adding: “The United Nations also says this in the 2030 Agenda for Sustainable Development, namely that we must guarantee access to drinking water for all.”
Produce drinking water from the air
An approach that also includes a plant located in Dubai and equipped with panels producing drinking water.
“Today, 2.4 billion people do not have access to safe drinking water. In the future, 6 billion people will face water shortages,” recalls Sofia Berglundm, business development manager at Global Source, a company that manufactures these famous innovative panels. “Their operation is quite simple because you only need sunlight and air to be able to produce drinking water,” she points out.
“Our panels powered by photovoltaic cells which we call hydro-panels draw in ambient air, the air passes through our secret ingredient, the hygroscopic material, this material only absorbs H₂O molecules which we then turn into liquid into using the heat of the sun,” she explains. “This water is then mineralized so that it is better for human health, there are no pollutants, nothing can enter the water before it is mineralized,” she says.
Rely on natural cycles
Prototypes like the one developed by Manhattan in the Emirates rely on natural cycles to reduce energy consumption related to water recovery.
“Everyone knows that solar radiation causes water to evaporate; whether it is a swimming pool, an ocean, a lake or a river, water evaporates and then rises to form clouds and return as rain,” recalls Saeed Al Hassan, founder of the company. “So we decided to capture this water that evaporates from these bodies of water so that we could use it in different applications,” he indicates.
“This technology is useful not only in arid areas, but also in regions where the rate of evaporation increases dramatically such as during the heat wave that hit Europe last year,” he says. “Instead of letting this water evaporate, it can be captured to grow crops when it is in season while rivers can be replenished through the natural cycle,” he adds.
These innovations respond to the essential issue of drinking water supply in a context of climate change and increasing world population.
Technologies capable of producing drinking water in the middle of the desert