经济学人下载:有废铁吗?

Science and technology
科学与技术

Water purification
水的净化

Any old iron?
有废铁吗？

A little-known chemical may provide a new way to clean water
一种鲜为人知的化学物质可能为清洁水源带来一线希望

IRON in water is normally regarded a pollutant.
水中的铁原子通常被认为是一种污染源。

Luke Daly, the boss of Ferrate Treatment Technologies of Orlando, Florida, however, plans to turn that thought on its head.
然而，弗罗里达州奥兰多高铁酸盐技术处理所所长Luke Daly，计划颠倒这一认知。

He intends to use a chemically unusual form of iron to clean water up, not make it dirty.
他将利用铁原子的一种非通常化学形态来净化水源，而非污染水源。

Iron is found in the part of the periodic table known as the transition metals.
铁是化学元素周期表中的一部分，也被熟知为过渡金属。

Like all metals, these react with other elements by giving up electrons to form positively charged ions.
像所有的金属一样，铁原子与其他元素反应，释放电子形成带正电的离子。

Transition metals, though, give up different numbers of electrons in different circumstances, and thus have ions of various charges.
但过渡金属在不同的情况下释放不同数量的电子，因此就形成乐携带不同数目正电的离子。

Usually, iron loses two or three electrons.
通常情况下，铁原子丧失2-3个电子。

But in ferrates, which are compounds of iron and oxygen with non-transition metals like sodium and calcium, it loses six.
但是在高铁酸盐中是铁原子、氧原子以及非过渡金属如纳原子、钙原子的化合物，它失去了6个电子。

That makes ferrates extremely reactive, and it is this reactivity which Mr Daly hopes to exploit.
这使得高铁酸盐极其具有活性，而这也是Daly先生希望挖掘出的活性。

First, ferrates are strong oxidising agents.
首先，高铁酸盐是强氧化剂。

That means they destroy bacteria and viruses, and break up organic molecules with alacrity.
也就是说，它们能够破坏细菌和病毒，并能迅速分解有机分子。

Second, they are coagulants and flocculating agents.
其次，它们也是凝结剂和絮凝剂，

They attract other chemicals in the water, including dissolved metals, and precipitate them for easy removal.
吸引水中其他的化学物质并生成沉淀就可以毫不费力的去除掉。

Moreover, once it has done its job, the iron in ferrates precipitates too, as iron oxide, leaving pure water behind.
此外，当它的使命结束后，高铁酸盐中的铁离子也会以氧化铁的形式沉淀，过滤后就是洁净的水了。

The reason these wonder materials have not been used as water purifiers before is that their reactivity makes them unstable and thus difficult to store.
先前这些神奇的物质并没有用来做水源净化剂，因为它们的活性使得本身不稳定，也难以储存。

Thomas Waite of the Florida Institute of Technology, an academic scientist on whose work the company has drawn, jokes that in the early days of his research he kept the whole world's supply of ferrates in a cabinet in his laboratory.
佛罗里达理工学院的理论科学家Thomas Waite，开玩笑的说，在他的早期研究中，当年全世界量的高铁酸盐供应量都在他的实验室橱柜中。

Ferrate Treatment Technologies' trick is to make ferrates on site, for instant use, rather than attempting to transport them to where they are needed.
高铁酸盐技术处理所所玩的戏法就是将高铁酸盐现场即用，而非运送到异地再使用。

The firm's Ferrator uses three cheap raw materials—bleach, ferric chloride and caustic soda—to produce sodium and calcium ferrate at a price competitive, in terms of oxidising power, with more familiar water-cleaners like chlorine and ozone.
公司的高铁酸盐系统是用三种便宜的原材料—漂白剂、氯化铁以及氢氧化钠—来制造高铁酸钠和高铁酸钙，并使其价格，在氧化效果来看，媲美于氯水和臭氧这类的水源清洁剂。

A machine small enough to be carried around in a pickup truck, Mr Daly claims, could generate enough ferrates to purify 75m litres of water a day.
Daly先生称，一个足以让小货车携带的小型机器，能够制造出足够的高铁酸盐一天净化7500万公升的水。

The system is now being tested at two plants in Florida.
这套系统现正在接受位于弗罗里达州两座工厂的测试。

If all goes well, the first commercial Ferrators will be up and running later this year.
如果一切正常的话，第一个商业性高铁酸盐系统将建立并且于年后投入运营。