Water Desalination and Reuse Center, Division of Biological and Environmental Science and Engineering , King Abdullah University of Science and Technology , Thuwal , 23955-6900 , Saudi Arabia.
Environ Sci Technol. 2018 Oct 2;52(19):11367-11377. doi: 10.1021/acs.est.8b02852. Epub 2018 Sep 20.
The Earth's atmosphere holds approximately 12 900 billion tons of fresh water distributed all over the world with fast replenishment. Atmospheric water harvesting is emerging as a promising strategy for clean water production in arid regions, land-locked areas, and remote communities. The water vapor sorbent is the key component for atmospheric water harvesting devices based on absorbing-releasing process. In this work, a flexible hybrid photothermal water sorbent composed of deliquescent salt and hydrogel was rationally fabricated. It possesses superior water sorption capacity even in low humidity air thanks to the deliquescent salt and maintains a solid form after it sorbs a large amount of water owing to the hydrogel platform. The harvested water could be easily released under regular sunlight via the photothermal effect, and it can be directly reused without noticeable capacity fading. An "easy-to-assemble-at-household" prototype device with 35 g of the dry hydrogel was tested outdoors under field conditions and delivered 20 g of fresh water within 2.5 h under natural sunlight. It is estimated that the material cost of making such a device to supply minimum daily water consumption for an adult (i.e., 3 kg) is only $3.20 (USD). This type of atmospheric water generator (AWG) is cheap and affordable, works perfectly with a broad range of humidity, does not need any electricity, and thus is especially suitable for clean water production in remote areas.
地球的大气层中大约含有 12900 亿吨分布在世界各地的淡水，并且可以快速补充。大气水采集作为一种在干旱地区、内陆地区和偏远社区生产清洁水的有前途的策略正在出现。水汽吸附剂是基于吸收-释放过程的大气水采集装置的关键组成部分。在这项工作中，合理地制备了一种由潮解盐和水凝胶组成的柔性混合光热吸水剂。由于潮解盐的存在，即使在低湿度空气中，它也具有优异的吸水能力，并由于水凝胶平台的存在，在吸附大量水后仍保持固体形式。采集到的水可以通过光热效应在普通阳光下轻松释放，并且可以直接重复使用，而不会出现明显的容量衰减。一个“易于在家中组装”的原型设备，使用 35 克干水凝胶，在野外条件下进行了户外测试，在自然阳光下 2.5 小时内可提供 20 克淡水。据估计，制造这种设备以供应成年人（即 3 公斤）的最低日用水量的材料成本仅为 3.20 美元（USD）。这种大气水收集器（AWG）价格便宜，价格实惠，适用于广泛的湿度范围，不需要任何电力，因此特别适合在偏远地区生产清洁水。
