Why don’t we get our drinking water from the ocean? - Manish Kumar

翻译人员: enxi xie 校对人员: Marie Li

You're stranded at sea and getting thirsty.

你被困在海里，口渴了。

Water fills the horizon— but you know you’re not supposed to drink it.

水填满了地平线—但你知道你不应该喝它。

So, what would actually happen to you if you did?

那么，如果你这样做了，你到底会发生什么？

And how can you find a way to hydrate?

那你怎么能找到补水的方法呢？

The danger in drinking saltwater lies at the cellular level.

喝盐水的危险存在于细胞层面。

To maintain their structural integrity,

为了保持其结构完整性，

your body’s cells match the concentration of certain ions, like salt,

人体细胞会将某些离子（例如盐）

within their membranes with the concentration outside of them—

的浓度与其外部（例如血液中）

in your bloodstream, for instance.

的浓度相匹配。

Seawater is about four times saltier than your blood.

海水的盐度大约是你的血液的四倍。

So when it's ingested, the fluid outside your cells becomes much saltier.

因此，当它被摄入时， 细胞外的液体会变得更咸。

To relieve the resulting pressure difference,

为了缓解由此产生的压差，

water flows out of your cells.

水会流出您的细胞。

Your kidneys use this water to begin removing the excess salt—

你的肾脏使用这种水开始去除多余的盐分，

but they require much more freshwater to actually flush it all out.

但它们需要更多的淡水才能真正将其全部冲走。

Consuming enough seawater without any freshwater can lead to salt poisoning.

在没有任何淡水的情况下 摄入足够的海水会导致盐中毒。

The effects can be devastating as the body's cells lose water and contract.

随着人体细胞流失水分并收缩， 其影响可能是毁灭性的。

This can cause tissues to shift and rupture

这可能导致组织移位和破裂，

and fluids to collect in critical organs.

液体积聚在关键器官中。

Overall, drinking seawater only makes things worse.

总的来说，喝海水只会使情况变得更糟。

Survival depends on finding— or creating— freshwater.

生存取决于寻找或创造淡水。

In the 4th century BCE,

在公元前4世纪，

Greek philosopher Aristotle described two main modes of seawater desalination,

希腊哲学家亚里士多德 描述了两种主要的海水淡化模式，

which are still used today.

这些模式至今仍在使用。

One is thermal,

一种是热的，

and relies on heating seawater to yield vaporized condensed freshwater,

它依靠加热海水来产生蒸发的冷凝淡水，

a method ancient Greek sailors used regularly.

这是古希腊水手经常使用的方法。

The other is reverse osmosis,

另一种是反渗透，

which uses pressure to push seawater through a salt-filtering membrane—

它利用压力将海水推过盐过滤膜——

a process Aristotle documented with a sealed wax jar.

亚里士多德用密封的蜡罐记录了这一过程。

In the intervening millennia,

在此之后的几千年中，

people continued using and innovating on these methods.

人们继续使用和创新这些方法。

Making potable freshwater from seawater is a bigger project now than ever.

现在，从海水中生产饮用淡水是 一个比以往任何时候都更大的项目。

Today, 2 billion people can't access clean drinking water,

如今，有20亿人无法获得清洁的饮用水，

and 87 different countries,

预计到2050年，87个不同的国家，

including many currently considered “water rich,”

包括许多目前被认为

are projected to be “water scarce” by 2050.

是 “水资源丰富” 的国家，将 “缺水”。

As of 2022, the world’s largest desalination plant

截至2022年，世界上最大的海水

turned over 2 billion liters of saltwater into drinkable freshwater

淡化厂每天将超过20亿 升的盐水转化为可饮用的淡水，

every day using mostly thermal technology.

主要使用热技术。

But this method has drawbacks.

但是这种方法有缺点。

A lot of energy is required to generate the necessary heat,

产生必要的热量需要大量能量，

which is usually provided by fossil fuels.

而热量通常由化石燃料提供。

Thermal desalination plants also produce considerable waste in the form of brine—

热海水淡化厂还会以盐水的形式产生大量废物，

ultra-concentrated saltwater that can be harmful

即超浓缩的盐水，如果简单

if simply returned to natural bodies of water.

地返回到自然水体，就会有害。

Many see more promise in reverse osmosis,

许多人认为反渗透还有更多前景，如今，

which nowadays uses synthetic membranes to filter out salt and other impurities.

反渗透使用合成膜来过滤盐和其他杂质。

Overall, it’s more energy-efficient and less briny than thermal desalination.

总体而言，与热海水淡化相比， 它更节能，含盐量更少。

As of 2020, around 17,000 desalination plants

截至2020年，约有 17,000座海水淡化厂为超过3亿人

supplied more than 300 million people with freshwater,

提供了淡水，

most of them using reverse osmosis.

其中大多数使用反渗透。

Those numbers are increasing.

这些数字正在增加。

But waste, cost, efficiency, and sustainability remain big issues.

但是，浪费、成本、 效率和可持续性仍然是大问题。

More research is needed to make renewable-powered desalination plants

要使可再生能源海水淡化厂在更大范围内具有

energy- and cost-effective at larger scales.

能源和成本效益，还需要进行更多的研究。

Meanwhile, another body of water appears promising

同时，另一片水域似乎有望

in combating water scarcity: wastewater.

应对水资源短缺：废水。

Reverse osmosis membranes actually require less energy to remove contaminants

实际上，与淡化盐水相比，反渗透膜

and the small amounts of salt found in wastewater

去除污水中的污染物和少量

than they do to desalinate saltwater.

盐分所需的能量要少。

And, importantly, wastewater recycling operations

而且，重要的是，废水回收业务

still yield pure, safe drinking water.

仍能产生纯净、安全的饮用水。

Okay, but back to the boat stranded at sea.

好吧，但是回到搁浅在海上的船上。

First, a couple dehydration don’ts.

首先，有几个人不应该脱水。

Drinking your own urine isn’t recommended

不建议自己喝尿，

because a few days of filtering accumulating waste products

因为在没有任何淡水救济

without any freshwater relief can cause kidney damage.

的情况下过滤/积累的废物 几天会造成肾脏损伤。

And while it might feel counterintuitive, if you don’t have any freshwater to drink,

虽然这可能会让人感觉违反直觉， 但如果你没有淡水可以喝，

it’s best not to eat— especially protein-rich food—

最好不要吃特别富含蛋白质的食物，

because your body doesn’t have enough water to digest it

因为你的身体没有足够的水来消化它们，

without becoming more dehydrated.

而不会变得更加脱水。

You can, however, work to secure freshwater sources

但是，你可以

using any water-wicking materials you can find to help collect rain and dew.

使用任何能找到的吸水材料来保护新的水源， 以帮助收集雨水和露水。

And you could get a low-tech thermal desalination operation going

而且， 通过让海水在容器中晒太阳并收集冷凝水，

by letting seawater sunbake in containers and collecting the condensation.

你可以进行低技术含量的热海水淡化作业。

You can also try getting some hydration by drinking bird and turtle blood

你也可以尝试通过喝鸟血和海龟血和鱼的脊髓液

and fish spinal fluid and eyes.

和眼睛来补水。

Maybe that sounds unappealing—

也许这听起来没有吸引力，

but desperate times might call for a collection of thirst-quenching measures.

但绝望的时刻可能需要一系列解渴措施。