来源：《新科学家》
原文刊登日期：2020年10月14日
A device that can extract water from almost dry air using heat from sunlight could help provide a sustainable source of water in remote regions with limited access to electricity.
一种可以利用太阳光的热量从几乎干燥的空气中提取水分的装置，可能有助于为电力供应有限的偏远地区提供一种可持续的水源。
“In areas where water scarcity is a problem, it’s important to consider different technologies which provide water, particularly as climate change will exacerbate many water scarcity issues,” says Alina LaPotin at the Massachusetts Institute of Technology.
麻省理工学院的LaPotin说：“在水资源短缺成为问题的地区，考虑不同的供水技术很重要，特别是在气候变化将加剧许多水资源短缺问题的情况下。”
The device, developed by LaPotin and her colleagues, contains a material called a zeolite inside it, which collects water vapour from the air at night. During the day, heat from the sun collected at a “solar absorber” panel drives the release of the water from the material so it is suitable for use.
这种装置由LaPotin和她的同事开发，内含一种叫做沸石的材料，可以在夜间收集空气中的水蒸气。白天，“太阳能吸收器”面板从太阳收集的热量驱动材料释放水分，因此它适合使用。
Because the zeolite has a large internal surface area, it can absorb the tiny quantities of water held in almost dry air, says LaPotin. Modelling based on initial tests of her team’s device predicts it could produce water from air with a relative humidity as low as 20 per cent – levels seen in deserts. Existing atmospheric water harvesting devices, such as fog harvesting and dewing systems, only work at relative humidity levels of at least 50 per cent.
LaPotin说，因为沸石有很大的内表面积，它可以吸附几乎干燥空气中少量的水。基于她团队的设备的初步测试，模型预测它可以从相对湿度低至20%的空气中产生水，这是沙漠中常见的湿度水平。现有的大气水收集装置，如雾气采集和结露系统，只能在相对湿度至少50%的情况下工作。
Fog harvesting also carries the disadvantage of being geographically limited to areas with fog, and dewing systems need to consume a lot of energy to power refrigeration systems that cool air below its dew point, she says.
她说，雾气采集也有一个缺点，即在地理上局限于有雾的地区，而结露系统需要消耗大量的能源来驱动制冷系统，使空气冷却到露点以下。
“Unlike desalination technologies, atmospheric water harvesting is a strategy if there is no liquid water available,” says LaPotin. It is also suitable in areas without centralised water production infrastructure, she adds.
LaPotin说：“与海水淡化技术不同，如果没有液态水可用，大气水收集也是一种策略。”她补充说，这种方法也适用于没有集中供水基础设施的地区。
“We are interested in developing compact atmospheric water harvesting systems which focus more on portability and weight constraints,” says LaPotin. The box-shaped device is made of acrylic, aluminium and copper sheet metal, and currently weighs about 7 kilograms.
LaPotin说：“我们有兴趣开发更注重便携性和重量限制的紧凑型大气水收集系统。”这个盒子状的装置由亚克力、铝和铜板制成，目前重约7公斤。
During tests it was able to produce 0.77 litres of water each day for every square metre of solar absorber. LaPotin says her team is investigating ways to increase the amount of water that can be absorbed by the material inside the device, to increase its efficiency further.
在测试中，每平方米太阳能吸收器每天能产生0.77升水。LaPotin说，她的团队正在研究如何增加设备内部材料可以吸附的水量，以进一步提高其效率。
“New materials are being developed which have a higher uptake,” she says. “Incorporating these materials into our device would show even greater performance.”
她说：“新材料正在开发中，具有更高的吸收速度。将这些材料融入我们的设备将显示出更大的性能。”