In a first-of-its-kind study conducted at Tel Aviv University, researchers were able to produce water from the air the complied with the drinking water standards set both by the State of Israel and by the World Health Organization.
The researchers examined the quality of the water produced from water vapor in the Tel Aviv atmosphere, which is polluted by industry and massive construction, and found it suitable for drinking.
TAU graduate student Offir Inbar, who worked on the project, explained no filtration or treatment system was used in the study; the water that was produced was the water that was obtained from the air.
They performed a wide range of advanced chemical analyses of the water, and found that in the vast majority of cases, including during different seasons and at different times of the day, the water extracted from the air in the heart of Tel Aviv was safe to drink. In addition, with the help of a variety of innovative technologies for monitoring the composition of the atmosphere and by applying advanced statistical methods, for the first time the researchers were able to quantitatively link the process the air goes through in the days leading up to the point of water production and the chemical composition of the dew.
Inbar: “The study showed that wind direction greatly affects water quality, so for example when the wind comes from the desert we find more calcium and sulfur, that is, residues of desert dust aerosols, in the water. However, when the wind comes from the direction of the sea, we find higher concentrations of chlorine and sodium.
“Moreover, we found that the distant sources from which the air came before it reached the point of water production can be identified in the water. For example, water produced from air coming from the Sahara region differs in composition from water produced from air coming from Europe.”
The water quality was also affected by anthropogenic pollution from transportation and industry. “We found a direct link between the concentrations of ammonia, nitrogen oxides and sulfur dioxide in the air and the concentration of their decomposition products in water.
“We found low concentrations of copper, potassium, and zinc in the water, which probably come from man-made pollution. From a research point of view, the chemical link we found between the meteorological parameters and the composition of the water makes it possible for the first time to study the atmosphere using water extracted from it. And environmentally speaking, this link allows us to know what minerals should be added to water extracted from air in order to provide people with quality drinking water. In general, we found that potable water from air does not contain enough calcium and magnesium – and it is advisable to add these minerals to the water, as they are added to desalinated drinking water in some countries.”
Devices for generating water from the air that include water purification and treatment systems can already be found in a number of countries in the world, where they provide quality drinking water to people living in distressed areas.
The study was conducted by a team of experts from the hydrochemistry laboratory at the Porter School of Environment and Earth Sciences at Tel Aviv University, led by graduate student Offir Inbar and supervised by Prof. Dror Avisar, Head of TAU’s Moshe Mirilashvili Institute for Applied Water Studies. Also participating in the study was Watergen’s research and development team, Prof. Alexandra Chudnovsky, and leading researchers from Germany. The study’s results were published in two leading journals: Science of the Total Environment and Water.
The test was performed using a dedicated facility of the Israeli company Watergen, which partnered in the study.
Updated Tuesday, June 22, 2021 at 2:41 pm .