VOA慢速英语--科学家在污水中发现大量的贵金属

Scientists Find Large Amounts of Precious Metals in Wastewater

In recent months, stories about sewers¹ getting clogged² have made international headlines. For example, a so-called "fatberg," a mass of grease and diapers, clogged London's sewers.

A new study has found stranger materials in a wastewater system: large amounts of rare and precious metals.

Researchers examined 64 wastewater treatment centers across Switzerland. A government press release says it was the first study on trace elements in wastewater in an industrialized country.

The researchers found 3000 kg of silver and 43 kilograms of gold in effluent and sludge from the centers. The value of the materials was somewhere around $3.1 million dollars.

The silver and gold were in the form of tiny particles. The researchers said the particles were most likely released during manufacturing of chemicals, pharmaceuticals⁴, or watches.

Bas Vriens is one of the researchers. "You hear stories about an angry man or woman throwing jewelry⁵ down the toilet, but we didn't find any rings, unfortunately," he said.

"The levels of gold and silver were very small, in the micrograms, or even nanograms, but when you add them up it's pretty substantial."

The researchers also found large amounts of rare earth minerals.

The level of metal concentrations did not violate Swiss laws. They were removed before the water entered the drinking water system.

Vriens cautioned people against trying to find precious metals in drinking water. "It wouldn't make sense for people to boil their tap water to recover gold or silver because it has already been filtered out before it re-enters the drinking water supply," Vriens said.

I'm John Russell.

Words in This Story

clog³ – v. to slowly form a block in (something, such as a pipe or street) so that things cannot move through quickly or easily

diaper – n. a piece of cloth or other material that is placed between a baby's legs and fastened around the waist to hold body waste

grease – n. an oily substance

trace – n. a very small amount of something

effluent – n. liquid (such as sewage or industrial chemicals) that is released as waste

sludge – n. a soft, thick material that is produced in various industrial processes (such as in the treatment of sewage)

toilet – n. a large bowl attached to a pipe that is used for getting rid of bodily waste and then flushed with water

unfortunately – adv. used to say that something bad or unlucky has happened

1 sewers   

n.阴沟，污水管，下水道( sewer的名词复数 )

参考例句：

• The sewers discharge out at sea. 下水道的污水排入海里。 来自《现代汉英综合大词典》
• Another municipal waste problem is street runoff into storm sewers. 有关都市废水的另外一个问题是进入雨水沟的街道雨水。 来自英汉非文学 - 环境法 - 环境法

2 clogged   

（使）阻碍( clog的过去式和过去分词 )； 淤滞

参考例句：

• The narrow streets were clogged with traffic. 狭窄的街道上交通堵塞。
• The intake of gasoline was stopped by a clogged fuel line. 汽油的注入由于管道阻塞而停止了。

3 clog   

vt.塞满，阻塞；n.[常pl.]木屐

参考例句：

• In cotton and wool processing,short length fibers may clog sewers.在棉毛生产中，短纤维可能堵塞下水管道。
• These streets often clog during the rush hour.这几条大街在交通高峰时间常常发生交通堵塞。

4 pharmaceuticals   

n.医药品；药物( pharmaceutical的名词复数 )

参考例句：

• the development of new pharmaceuticals 新药的开发
• The companies are pouring trillions of yen into biotechnology research,especially for pharmaceuticals and new seeds. 这些公司将大量资金投入生物工艺学研究，尤其是药品和新种子方面。 来自《简明英汉词典》

5 jewelry   

n.（jewllery）（总称）珠宝

参考例句：

• The burglars walked off with all my jewelry.夜盗偷走了我的全部珠宝。
• Jewelry and lace are mostly feminine belongings.珠宝和花边多数是女性用品。