演講MP3+雙語(yǔ)文稿:保持河流清潔的鹽循環(huán)經(jīng)濟(jì)

聽(tīng)力課堂TED音頻欄目主要包括TED演講的音頻MP3及中英雙語(yǔ)文稿，供各位英語(yǔ)愛(ài)好者學(xué)習(xí)使用。本文主要內(nèi)容為演講MP3+雙語(yǔ)文稿:保持河流清潔的鹽循環(huán)經(jīng)濟(jì)，希望你會(huì)喜歡！

【演講者及介紹】Tina Arrowood

通過(guò)將科學(xué)、循環(huán)思維和顛覆性創(chuàng)新結(jié)合起來(lái)，蒂娜·阿羅伍德幫助人們?cè)O(shè)想了一個(gè)淡水不稀缺，而是管理良好的世界。

【演講主題】保持河流清潔的鹽循環(huán)經(jīng)濟(jì)

A circular economy for salt that keeps rivers clean

【中英文字幕】

翻譯者 Yanyan Hong 校對(duì)者 Yolanda Zhang

00:13

Growing up in northern Wisconsin, I've naturally developed a connection to the Mississippi River. When I was little, my sister and I would have contests to see who could spell "M-i-s-s-i-s-s-i-p-p-i" the fastest. When I was in elementary school, I got to learn about the early explorers and their expeditions, Marquette and Joliet, and how they used the Great Lakes and the Mississippi River and its tributaries to discover the Midwest, and to map a trade route to the Gulf of Mexico. In graduate school, I was fortunate to have the Mississippi River outside my research laboratory window at the University of Minnesota. During that five-year period, I got to know the Mississippi River. I got to know its temperamental nature and where it would flood its banks at one moment, and then shortly thereafter, you would see its dry shorelines.

我在威斯康星州北部長(zhǎng)大， 很自然地與密西西比河 產(chǎn)生了親密的連結(jié)。 小時(shí)候， 我會(huì)和姐姐比賽誰(shuí)能最先拼寫(xiě)出 “M-i-s-s-i-s-s-i-p-p-i（密西西比）”。 上小學(xué)時(shí)， 我學(xué)到了早期的探險(xiǎn)家 以及他們的冒險(xiǎn)， 馬奎特和朱莉特，以及他們是 如何通過(guò)五大湖，密西西比河 及其支流，發(fā)現(xiàn)了美國(guó)中西部， 并將到墨西哥灣的貿(mào)易路線畫(huà)成了地圖。 在讀研究生時(shí)， 我很幸運(yùn)，密西西比河正好 就在我所在的明尼蘇達(dá)大學(xué) 研究實(shí)驗(yàn)室窗外。 在那五年期間， 我有機(jī)會(huì)認(rèn)識(shí)了密西西比河， 我發(fā)掘了它無(wú)與倫比的特質(zhì)， 可能某一刻它會(huì)將河岸淹沒(méi)， 不久后， 干燥的河岸線又清晰可見(jiàn)了。

01:10

Today, as a physical organic chemist, I'm committed to use my training to help protect rivers, like the Mississippi, from excessive salt that can come from human activity. Because, you know, salt is something that can contaminate freshwater rivers. And freshwater rivers, they have only salt levels of .05 percent. And at this level, it's safe to drink. But the majority of the water on our planet is housed in our oceans, and ocean water has a salinity level of more than three percent. And if you drank that, you'd be sick very quick. So, if we are to compare the relative volume of ocean water to that of the river water that's on our planet, and let's say we are able to put the ocean water into an Olympic-size swimming pool, then our planet's river water would fit in a one-gallon jug. So you can see it's a precious resource.

今天，作為一位物理有機(jī)化學(xué)家， 我致力于利用我所學(xué)， 來(lái)保護(hù)像密西西比河這樣的河流， 避免因?yàn)槿祟?lèi)的活動(dòng)， 而造成河流鹽分升高。 因?yàn)?鹽分會(huì)污染淡水河流。 淡水河流的鹽分含量只有 0.05 %， 鹽分在這個(gè)范圍內(nèi)的水可以安全飲用。 但地球上大部分的水來(lái)自我們的海洋， 而海洋的鹽含量超過(guò) 3%， 如果飲用海水，你很快就會(huì)生病。 所以若要將地球上所有的海水 和河流水量相比較， 假設(shè)我們把海水放進(jìn) 奧運(yùn)標(biāo)準(zhǔn)游泳池中， 那么地球上的河流水量 就相當(dāng)于一加侖。 所以不難想到， 這是彌足珍貴的資源。

02:12

But do we treat it like a precious resource? Or rather, do we treat it like that old rug that you put in your front doorway and wipe your feet off on it? Treating rivers like that old rug has severe consequences. Let's take a look. Let's see what just one teaspoon of salt can do. If we add one teaspoon of salt to this Olympic-size swimming pool of ocean water, the ocean water stays ocean water. But if we add that same one teaspoon of salt to this one-gallon jug of fresh river water, suddenly, it becomes too salty to drink. So the point here is, because rivers, the volume is so small compared to the oceans, it is especially vulnerable to human activity, and we need to take care to protect them.

可是我們有把它當(dāng)作 珍貴的資源來(lái)對(duì)待嗎？ 或者，我們對(duì)待它的方式， 就像對(duì)待鋪在大門(mén)口的 老式地毯，頂多用來(lái)擦擦鞋？ 把河流當(dāng)作老地毯會(huì)導(dǎo)致嚴(yán)重的后果， 我們來(lái)看看。 我們來(lái)看看一茶勺的 鹽會(huì)有什么影響， 如果我們?cè)谝粋€(gè)裝滿(mǎn) 海水的奧運(yùn)會(huì)標(biāo)準(zhǔn)泳池中 加入一勺鹽， 海水依然是海水， 但是再加進(jìn)同樣一茶勺的鹽 到一加侖干凈河水中， 一下子整罐水就因太咸而無(wú)法飲用。 重點(diǎn)是因?yàn)椋?相比海洋，河流的水太稀少了， 它很容易受到人類(lèi)活動(dòng)的影響， 而我們需要小心地保護(hù)河流。

03:02

So recently, I surveyed the literature to look at the river health around the world. And I fully expected to see ailing river health in regions of water scarcity and heavy industrial development. And I saw that in northern China and in India. But I was surprised when I read a 2018 article where there's 232 river-sampling sites sampled across the United States. And of those sites, 37 percent had increasing salinity levels. What was more surprising is that the ones with the highest increases were found on the east part of the United States, and not the arid southwest. The authors of this paper postulate that this could be due to using salt to deice roads. Potentially, another source of this salt could come from salty industrial wastewaters.

最近，我通過(guò)調(diào)查文獻(xiàn)， 了解了全世界各地的河流健康問(wèn)題， 我完全預(yù)期會(huì)在水源稀少， 以及重度工業(yè)發(fā)展區(qū)看到“生病”的河流。 我的確在中國(guó)北部和印度看到了。 但讓我意外的是， 在一篇 2018 年最新的文章中， 提到在全美有 232 個(gè)河流抽樣站點(diǎn)， 對(duì)美國(guó)各地河流抽樣， 這些站點(diǎn)顯示， 在 37% 的地方發(fā)現(xiàn)鹽度超標(biāo)。 更讓人驚訝的是， 鹽度增加最多的站點(diǎn) 在美國(guó)東部， 而不是干旱的西南部。 這篇文章的作者推測(cè)， 原因可能是因?yàn)楫?dāng)?shù)厥褂?鹽來(lái)應(yīng)對(duì)道路結(jié)冰問(wèn)題， 另一個(gè)可能來(lái)源是 含鹽的工業(yè)廢水。

04:02

So as you see, human activities can convert our freshwater rivers into water that's more like our oceans. So we need to act and do something before it's too late. And I have a proposal.

如你所見(jiàn)，人類(lèi)的活動(dòng) 可能讓干凈的河流變成 更像是海水的水。 所以我們必須盡快行動(dòng)起來(lái)。 我有一項(xiàng)提議。

04:17

We can take a three-step river-defense mechanism, and if industrial-water users practice this defense mechanism, we can put our rivers in a much safer position. This involves, number one, extracting less water from our rivers by implementing water recycle and reuse operations. Number two, we need to take the salt out of these salty industrial wastewaters and recover it and reuse it for other purposes. And number three, we need to convert salt consumers, who currently source our salt from mines into salt consumers that source our salt from recycled salt sources. This three-part defense mechanism is already in play. This is what northern China and India are implementing to help to rehabilitate the rivers. But the proposal here is to use this defense mechanism to protect our rivers, so we don't need to rehabilitate them. And the good news is, we have technology that can do this. It's with membranes.

我們可以采取一個(gè) 三步計(jì)劃預(yù)防河流污染， 如果工業(yè)水的排放者 能采取這個(gè)預(yù)防步驟， 我們就可以讓河流更安全。 此內(nèi)容包括，第一， 導(dǎo)入水回收和再利用的方法， 從而減少河流取水。 第二， 我們必須將鹽分 從工業(yè)水中提取出來(lái)， 再利用到其他地方。 第三，我們要將目前 使用巖鹽的消費(fèi)者轉(zhuǎn)變成 使用回收鹽的消費(fèi)者。 這三個(gè)步驟的處理方法已在實(shí)施， 中國(guó)北部和印度正在 采用這一機(jī)制來(lái)補(bǔ)救河流。 但我提出的意見(jiàn)是， 要用這個(gè)預(yù)防機(jī)制 來(lái)保護(hù)我們的河流， 這樣就不需要事后再補(bǔ)救。 好消息是，我們可以使用薄膜技術(shù) 來(lái)實(shí)現(xiàn)。

05:26

Membranes that can separate salt and water. Membranes have been around for a number of years, and they're based on polymeric materials that separate based on size, or they can separate based on charge. The membranes that are used to separate salt and water typically separate based on charge. And these membranes are negatively charged, and help to repel the negatively charged chloride ions that are in that dissolved salt. So, as I said, these membranes have been around for a number of years, and currently, they are purifying 25 million gallons of water every minute. Even more than that, actually. But they can do more.

這種薄膜可以把鹽和水分離開(kāi)。 薄膜在很多年前就已存在， 采用的是聚合材料， 依據(jù)體積來(lái)進(jìn)行物質(zhì)分離， 也可以依據(jù)電荷來(lái)做分離。 用來(lái)將鹽和水分離的薄膜， 通常是根據(jù)電荷來(lái)做分離。 這些薄膜本身帶有負(fù)電荷， 能協(xié)助排斥溶解鹽中 帶負(fù)電荷的氯離子。 我剛才提到，這些薄膜 在很多年前就有了， 目前，它們每分鐘能 凈化兩千五百萬(wàn)加侖的水。 甚至更多。 但是它們能做的遠(yuǎn)不只這些。

06:13

These membranes are based under the principle of reverse osmosis. Now osmosis is this natural process that happens in our bodies -- you know, how our cells work. And osmosis is where you have two chambers that separate two levels of salt concentration. One with low salt concentration and one with high salt concentration. And separating the two chambers is the semipermeable membrane. And under the natural osmosis process, what happens is the water naturally transports across that membrane from the area of low salt concentration to the area of high salt concentration, until an equilibrium is met.

這些薄膜是以滲透原理為基礎(chǔ)的。 滲透是我們身體中 會(huì)發(fā)生的自然過(guò)程—— 和細(xì)胞的工作原理有關(guān)。 滲透作用就是有兩個(gè)不同的空間， 將兩種不同濃度的鹽溶液分開(kāi)， 一份是低鹽度， 另一份是高鹽度。 將兩個(gè)空間隔開(kāi)的是 一張半滲透性的薄膜。 在自然滲透的過(guò)程中， 水會(huì)很自然的通過(guò)薄膜， 從低鹽份濃度的地方 流動(dòng)到高鹽度濃度的地方， 直到兩邊的濃度達(dá)到平衡。

06:55

Now reverse osmosis, it's the reverse of this natural process. And in order to achieve this reversal, what we do is we apply a pressure to the high-concentration side and in doing so, we drive the water the opposite direction. And so the high-concentration side becomes more salty, more concentrated, and the low-concentration side becomes your purified water. So using reverse osmosis, we can take an industrial wastewater and convert up to 95 percent of it into pure water, leaving only five percent as this concentrated salty mixture. Now, this five percent concentrated salty mixture is not waste. So scientists have also developed membranes that are modified to allow some salts to pass through and not others. Using these membranes, which are commonly referred to as nanofiltration membranes, now this five percent concentrated salty solution can be converted into a purified salt solution. So, in total, using reverse osmosis and nanofiltration membranes, we can convert industrial wastewater into a resource of both water and salt. And in doing so, achieve pillars one and two of this river-defense mechanism.

逆滲透作用則是逆轉(zhuǎn)這個(gè)過(guò)程。 為了實(shí)現(xiàn)逆轉(zhuǎn)， 我們就要施加壓力 給高濃度的那一端， 這么做就能讓水往反方向流動(dòng)。 高濃度的那一端含鹽量會(huì)增加， 濃度更高， 而低濃度那一端 則會(huì)變成凈化過(guò)的水。 利用逆滲透方法， 我們可以把 95% 的工業(yè)用水轉(zhuǎn)化為干凈的水， 只留下 5% 高濃度的鹽混合物。 而這 5% 高鹽濃度的混合物 并非廢物。 科學(xué)家也研發(fā)出了改造過(guò)的薄膜， 讓某些鹽可以通過(guò)， 而其他的不行。 使用這些薄膜， 也就是我們熟知的納米過(guò)濾膜， 這 5% 的高濃度溶液， 就能被轉(zhuǎn)化成純鹽溶液， 所以，總的來(lái)說(shuō)， 有了逆滲透技術(shù)和納米薄膜， 我們就能把工業(yè)廢水 轉(zhuǎn)化成水和鹽， 這樣一來(lái)， 就能實(shí)現(xiàn)河流保護(hù)機(jī)制 的第一和第二步。

08:18

Now, I've introduced this to a number of industrial-water users, and the common response is, "Yeah, but who is going to use my salt?" So that's why pillar number three is so important. We need to transform folks that are using mine salt into consumers of recycled salt. So who are these salt consumers? Well, in 2018 in the United States, I learned that 43 percent of the salt consumed in the US was used for road salt deicing purposes. Thirty-nine percent was used by the chemical industry.

我曾向一些工業(yè)水 使用者介紹了這個(gè)機(jī)制， 通常得到的反饋是， “不錯(cuò)啊，但是誰(shuí)會(huì)要我的鹽呢？” 這就是為什么第三步很關(guān)鍵， 我們必須要將使用巖鹽的消費(fèi)者， 轉(zhuǎn)化為使用回收鹽的消費(fèi)者， 那么這些消費(fèi)者是誰(shuí)呢？ 2018 年， 我發(fā)現(xiàn)美國(guó)消費(fèi)鹽的人當(dāng)中 43% 都是把鹽用在防止道路結(jié)冰上。 39% 是化學(xué)工業(yè)在使用。

08:56

So let's take a look at these two applications. So, I was shocked. In the 2018-2019 winter season, one million tons of salt was applied to the roads in the state of Pennsylvania. One million tons of salt is enough to fill two-thirds of an Empire State Building. That's one million tons of salt mined from the earth, applied to our roads, and then it washes off into the environment and into our rivers. So the proposal here is that we could at least source that salt from a salty industrial wastewater, and prevent that from going into our rivers, and rather use that to apply to our roads. So at least when the melt happens in the springtime and you have this high-salinity runoff, the rivers are at least in a better position to defend themselves against that.

我們來(lái)看看這兩種應(yīng)用。 我很震驚， 在 2018 年到 2019 年冬季， 一百萬(wàn)噸的鹽被用在 賓夕法尼亞州的道路上。 一百萬(wàn)噸的鹽足以 裝滿(mǎn)三分之二的帝國(guó)大廈。 也就是說(shuō)從地球上 開(kāi)采出了一百萬(wàn)噸的鹽， 用于我們的道路， 接著這些鹽就 被沖刷進(jìn)了我們的河流。 所以我的提議是，至少我們可以 從含鹽的工業(yè)廢水中提取那些鹽， 避免這些鹽進(jìn)入我們的河流， 把它們使用在我們的道路上。 這樣至少在春季融冰之時(shí)， 出現(xiàn)高鹽度的徑流時(shí)， 我們的河流狀況會(huì)更好， 可以有強(qiáng)的抵抗能力。

09:54

Now, as a chemist, the opportunity though that I'm more psyched about is the concept of introducing circular salt into the chemical industry. And the chlor-alkali industry is perfect. Chlor-alkali industry is the source of epoxies, it's the source of urethanes and solvents and a lot of useful products that we use in our everyday lives. And it uses sodium chloride salt as its key feed stack. So the idea here is, well, first of all, let's look at linear economy.

身為一名化學(xué)家， 更讓我激動(dòng)的機(jī)會(huì)是 把循環(huán)鹽導(dǎo)入化學(xué)工業(yè)這個(gè)概念。 氯堿工業(yè)是個(gè)理想的對(duì)象， 它是環(huán)氧樹(shù)脂的來(lái)源， 也是聚氨酯和各種溶劑， 以及我們?nèi)粘Ｉ钪?許多實(shí)用產(chǎn)品的來(lái)源。 該產(chǎn)業(yè)使用氯化鈉鹽 作為主要的原材料。 所以我的想法是—— 首先，我們先來(lái)談?wù)劸€性經(jīng)濟(jì)。

10:31

So in a linear economy, they're sourcing that salt from a mine, it goes through this chlor-alkali process, made into a basic chemical, which then can get converted into another new product, or a more functional product. But during that conversion process, oftentimes salt is regenerated as the by-product, and it ends up in the industrial wastewater. So, the idea is that we can introduce circularity, and we can recycle the water and salt from those industrial wastewater streams, from the factories, and we can send it to the front end of the chlor-alkali process. Circular salt.

在線性經(jīng)濟(jì)中， 人們從一個(gè)礦里找鹽， 它會(huì)經(jīng)歷這個(gè)氯堿過(guò)程， 被制成基本的化學(xué)物質(zhì)， 接著又被轉(zhuǎn)換成其他新的產(chǎn)品， 或者更有功能性的產(chǎn)品， 但在轉(zhuǎn)換過(guò)程中， 通常都會(huì)重新 生成鹽，算是副產(chǎn)品， 這些鹽也會(huì)進(jìn)入工業(yè)廢水。 所以，我們可以導(dǎo)入循環(huán)， 從工廠回收工業(yè)廢水中 的水和鹽， 再把它送到氯堿處理的前端。 這就是循環(huán)鹽。

11:12

So how impactful is this? Well, let's just take one example. Fifty percent of the world's production of propylene oxide is made through the chlor-alkali process. And that's a total of about five million tons of propylene oxide on an annual basis, made globally. So that's five million tons of salt mined from the earth converted through the chlor-alkali process into propylene oxide, and then during that process, five million tons of salt that ends up in wastewater streams. So five million tons is enough salt to fill three Empire State Buildings. And that's on an annual basis. So you can see how circular salt can provide a barrier to our rivers from this excessive salty discharge.

那么這會(huì)有多大的影響呢？ 讓我舉個(gè)例子。 全世界的環(huán)氧丙烷有 50% 是通過(guò)氯堿過(guò)程制作出來(lái)的， 也就是全球每年總共生產(chǎn) 約五百萬(wàn)噸的環(huán)氧丙烷。 那么，從地球開(kāi)采的五百萬(wàn)噸鹽， 通過(guò)氯堿過(guò)程轉(zhuǎn)換成環(huán)氧丙烷， 在這個(gè)過(guò)程中， 五百萬(wàn)噸的鹽最后會(huì)進(jìn)入廢水中。 五百萬(wàn)噸的鹽 足以填滿(mǎn)三個(gè)帝國(guó)大廈， 那還只是一年的量。 這樣大家就可以了解到 為什么循環(huán)鹽 可以幫助我們的河流 抵御過(guò)多的鹽排放。

12:05

So you might wonder, "Well, gosh, these membranes have been around for a number of years, so why aren't people implementing wastewater reuse? Well, the bottom line is, it costs money to implement wastewater reuse. And second, water in these regions is undervalued. Until it's too late. You know, if we don't plan for freshwater sustainability, there are some severe consequences. You can just ask one of the world's largest chemical manufacturers who last year took a 280-million dollar hit due to low river levels of the Rhine River in Germany. You can ask the residents of Cape Town, South Africa, who experienced a year-over-year drought drying up their water reserves, and then being asked not to flush their toilets.

各位可能會(huì)納悶， “哦，天吶，很多年 以前就有這些薄膜了， 為什么大家都不去做 廢水循環(huán)利用呢？ 根本原因就是， 做廢水再利用需要資金。 其次， 在這些區(qū)域水的價(jià)值被低估了， 沒(méi)有及時(shí)進(jìn)行循環(huán)再利用。 如果我們不規(guī)劃淡水的可持續(xù)性， 就將要面臨嚴(yán)重的后果。 可以問(wèn)問(wèn)世界上最大的化學(xué)品制造商， 去年，他們因?yàn)榈聡?guó)萊茵河水位過(guò)低， 遭受了 2 億 8 千萬(wàn)美金的損失， 也可以問(wèn)問(wèn)南非開(kāi)普敦的人民， 他們遇到了一年比一年嚴(yán)重的干旱， 讓所有儲(chǔ)存的水被耗盡， 甚至被限制沖馬桶，以節(jié)省水源。

12:59

So you can see, we have solutions here, with membranes, where we can provide pure water, we can provide pure salt, using these membranes, both of these, to help to protect our rivers for future generations.

所以我們可以看到， 現(xiàn)在我們有解決辦法，那就是薄膜， 用這個(gè)方法可以得到純凈水， 得到純鹽， 一石二鳥(niǎo)。 為未來(lái)的世代，保護(hù)我們的河流吧。

13:15

Thank you.

謝謝。

13:16

(Applause)

（掌聲）