Only 2.5% of the water on Earth is fresh water and only less than 1% is accessible to
human consumption. Landlocked and desert communities and communities that are not
wealthy enough to provide clean drinking water via conventional water treatment
technologies are facing severe water shortages and tend to rely on long distance
transportation to supply fresh water for their daily use.
As a lot of the water-scarce
countries have abundant annual solar irradiation and relatively high humidity, this
project proposes a technology that harvests water from ambient air using an anhydrate
salt and releases it for collection using sunlight. This technology is designed to be
potentially deployed in night-day cycles, as the humidity at night is at its peak, and solar
irradiation during the day is also at its peak.
In this work, a mesoporous silica powder
filled with CuCl2 and coated with carbon nanotubes is used. The water capture
performance of this material was investigated with different relative humidity
environments. Furthermore, the powder agglomeration sizes of this material were also
investigated for each relative humidity environment. Water release was investigated
under 1 kW/m2 simulated solar light in an in-lab ~60% relative humidity environment.
The results show that this mesoporous material was able to capture water at 12%
relative humidity conditions, low enough to capture water from the air in the Sahara
At relative humidity of 15% and 35%, the material was able to absorb 0.12 and
0.25 kg/kg of water, respectively, within 100 minutes, which indicates its fast water
harvesting kinetics. A fully hydrated sample released 0.26 kg/kg of water in almost half
an hour under 1 kW/m2 simulated sunlight. This project sheds more light on utilizing the
atmosphere as an alternative water source.
|Date of Award||Nov 2018|
|Original language||English (US)|
- Physical Science and Engineering
|Supervisor||Peng Wang (Supervisor)|
- Carbon nanotubes
- atomospheric water
- drinking water
- Anhydrate salt