An advanced solar technology, featuring a unique gel and system architecture, effectively draws water from the air. This innovation has the potential to transform water accessibility in dry, sun-drenched areas, providing essential water for drinking and various other purposes. (Depicted in artist’s concept.) Source: SciTechPost.com
Utilizing a hygroscopic gel and salts, this atmospheric water harvester supplies water to arid communities.
Currently, over 2.2 billion individuals reside in countries facing water scarcity, and annually, 3.5 million deaths are attributed to water-related diseases, according to the United Nations. The urgent need for clean drinking water in the sunniest parts of the globe has sparked significant interest in utilizing solar energy for water procurement.
A team from Shanghai Jiao Tong University in China has developed a novel solar-powered technology for harvesting atmospheric water. This could be a crucial solution for providing sufficient drinking water in harsh, dry regions. Their research was documented in Applied Physics Reviews, a journal of AIP Publishing.
Ruzhu Wang, the study’s author, stated, “This technology for harvesting atmospheric water could be instrumental in augmenting daily water supply for various needs, including household drinking water, industrial usage, and personal hygiene.”
Addressing Historical Obstacles
Previously, integrating salt into hydrogels posed a challenge, as higher salt concentrations diminished the hydrogel’s ability to swell due to the salting-out effect, resulting in salt leakage and reduced water absorption.
“We were intrigued to find that even with the addition of up to 5 grams of salt per gram of polymer, the resultant gel exhibited effective swelling and salt retention capabilities,” mentioned Wang.
Daytime atmospheric water harvesting cycle diagram. Courtesy of Wang Ruzhu.
Revolutionary Hygroscopic Gel and System Layout
The researchers created a highly hygroscopic gel using plant derivatives and hygroscopic salts, capable of absorbing and retaining a remarkable volume of water. In arid atmospheric conditions, one kilogram of this dry gel could absorb 1.18 kilograms of water, and up to 6.4 kilograms in more humid conditions. The preparation of this hygroscopic gel is both straightforward and cost-effective, making it feasible for mass production.
Moreover, the team designed a prototype with separate desorption and condensation chambers arranged side by side. They incorporated a turbofan in the condensation chamber, enhancing the recovery rate of desorbed water to over 90%.
During outdoor prototype tests, they observed that the system released absorbed water even under weak sunlight in the morning or afternoon. The system was also capable of simultaneous adsorption and desorption throughout the day.
Prospective Developments and Enhancements
The research team plans to leverage renewable energy for concurrent adsorption and desorption, aiming to maximize the daily water output per unit mass of the adsorbent and further refine the system for practical water generation applications.
Beyond daily water production, materials that capture atmospheric water could also be significant in future uses like dehumidification, agricultural irrigation, and thermal management in electronic devices.
Citation: “Daytime air–water harvesting based on super hygroscopic porous gels with simultaneous adsorption–desorption” by Chengjie Xiang, Xinge Yang, Fangfang Deng, Zhihui Chen and Ruzhu Wang, 5 December 2023, Applied Physics Reviews.
DOI: 10.1063/5.0160682
Table of Contents
Frequently Asked Questions (FAQs) about Solar-powered water harvesting
What is the key innovation in the new solar-powered water harvesting technology?
The breakthrough involves using a super hygroscopic gel and an efficient system design to extract water from the atmosphere. This technology is particularly beneficial for arid, sunny regions, providing a vital source of drinking water and addressing water scarcity.
How does this technology help communities in arid areas?
This atmospheric water harvester utilizes a hygroscopic gel and salts to provide water to communities in dry areas. It’s designed to meet the critical needs for drinking water and can also be used for industrial and personal hygiene purposes.
Who developed this solar-powered atmospheric water harvesting technology?
Researchers from Shanghai Jiao Tong University in China developed this promising technology. Their work was published in the journal Applied Physics Reviews by AIP Publishing.
What are the future applications and optimizations planned for this technology?
The research team aims to use renewable energy for simultaneous adsorption and desorption to maximize water yield. Potential future applications include dehumidification, agricultural irrigation, and thermal management for electronic devices.
More about Solar-powered water harvesting
- SciTechPost.com
- Applied Physics Reviews
- Shanghai Jiao Tong University
- United Nations Water-Related Statistics
- AIP Publishing Journal Information
