Machine turns sweat into drinking water for Unicef
在瑞典，一部能够从浸满汗水的衣服上提取出安全纯净饮用水的汗水提取机进入了人们的视线。这部机器通过高速旋转和加热待提取的衣服，从而使汗水变成蒸汽与衣物分离，再经过一层特殊设计的过滤网，让水分子得以通过，而细菌、衣物纤维等物质被隔离开来，如此就提取到了据称比当地自来水还要清洁的饮用水。这部机器为联合国儿童基金会设计，旨在让人们认识到世界上还有7.8亿人口仍然面临干净饮用水短缺的问题。该机器亮相以来，已有超过一千位哥德堡市民喝过“别人的汗水”。
汗水提取机的设计者表示，该机器的原理类似于国际太空站的尿液净化循环系统，但造价却低廉很多。不过，该项设计的局限在于，产出的水量太少。正常情况下从一件汗湿的T恤上所提取出的汗水只够转化成10毫升饮用水，仅够“喝一口”。此次活动组织方负责人表示，汗水的供应量永远都跟不上人们对饮用水的需求量，解决饮用水短缺的问题可能有别的更好的办法，比如水净化药剂。
A machine that takes sweat-laden clothes and turns the moisture into drinking water is in use in Sweden.
The device spins and heats the material to remove the sweat, and then passes the vapour through a special membrane designed to only let water molecules get through.
Since its Monday launch, its creators say more than 1,000 people have "drunk other's sweat" in Gothenburg.
They add the liquid is cleaner than local tap water.
The device was built for the United Nation's child-focused charity Unicef to promote a campaign highlighting the fact that 780 million people in the world lack access to clean water.
The machine was designed and built by engineer Andreas Hammar, known locally for his appearances on TV tech show Mekatronik.
He said the critical part of the sweat machine was a new water purification component developed by a company named HVR in collaboration with Sweden's Royal Institute of Technology.
"It uses a technique called membrane distillation," he told the BBC.
"We use a substance that's a bit like Gortex that only lets steam through but keeps bacteria, salts, clothing fibres and other substances out.
"They have something similar on the International Space Station to treat astronaut's urine - but our machine was cheaper to build.
Volunteers have been sampling the treated sweat since the start of the week in Gothenburg
"The amount of water it produces depends on how sweaty the person is - but one person's T-shirt typically produces 10ml [0.3oz], roughly a mouthful."
The kit has been put on show at theGothia Cup - the world's largest international youth football tournament.
MattiasRonge, chief executive of Stockholm-based advertising agency Deportivo - which organised the stunt - said the machine had helped raise awareness for Unicef, but in reality had its limitations.
"People haven't produced as much sweat as we hoped - right now the weather in Gothenburg is lousy," he said.
"So we've installed exercise bikes alongside the machine and volunteers are cycling like crazy.
"Even so, the demand for sweat is greater than the supply. And the machine will never be mass produced - there are better solutions out there such as water purifying pills."
(Source: BBC News)
