The World Economic Forum has listed the water crisis among the top five risks in terms of its potential impact for eight consecutive years. The global scarcity of water has not only led to around 4 billion people lacking access to safe drinking water at least one month out of the year, but also poses a severe threat to the operations and supply chain of many water-intensive industries.
Harvesting water from air, or atmospheric water generation (AWG), has inspired increasing research efforts to provide an alternative water supply, but making it economically feasible has always been a great challenge. Traditionally, AWG is achieved by cooling air below its dew point to condense the water vapor, which is a highly energy-intensive, climate-dependent process.
Desiccants, which have a natural tendency to absorb moisture, have been brought into play to reduce the energy consumption for removing water from the atmosphere, while conventional materials like silica gels, calcium chloride, and zeolites suffer from low water uptake and a high temperature requirement for desorption. Researchers at the National University of Singapore (NUS) have developed a highly water-absorbing, easily regenerable hydrogel to specifically address these drawbacks and improve the overall energy efficiency and applicability of desiccant-assisted AWG.