Scientists Find Large Amounts of Precious Metals in Wastewater
In recent months, stories about sewers getting clogged 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, pharmaceuticals, or watches.
Bas Vriens is one of the researchers. "You hear stories about an angry man or woman throwing jewelry 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.
1.filter out 过滤掉
Children should have glasses which filter out UV rays.
2.tap water 自来水
He never drinks tap water.
3.precious metals 贵重金属
Platinum and gold are precious metals.
4.trace elements 微量元素
Egg of trace elements, such as selenium, zinc also has anti-cancer effects.
5.For example, a so-called "fatberg," a mass of grease and diapers, clogged London's sewers.
a mass of 大量的
On his desk is a mass of books and papers.
In the spring, the meadow is a mass of daffodils.
6."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
make sense 有意义；讲得通
There are some stylistic elements in the statue that just don't make sense.
Provided you didn't try to make sense of it, it sounded beautiful.
近几个月来，下水道堵塞的新闻登上了国际新闻头条 。例如，由大量油脂和尿布堆积成的“油脂块”堵塞了伦敦的下水道 。
研究人员检测了瑞士64家污水处理中心 。政府的一份新闻稿里指出，这是首次在工业化国家进行污水微量元素的研究 。
研究人员从污水处理中心的废水和污泥中发现了3000千克的银和43公斤的金 。这些贵重金属的价值约310万美元 。
这些金银皆是微小颗粒 。研究人员表示，这些颗粒很有可能是在制造化学物质、药品或手表的时释放出来 。
巴斯·韦瑞恩（Bas Vriens）是研究员之一 。“你听过男性或女性一气之下将首饰扔进马桶，而不幸的是，我们从未发现过任何戒指 。”
饮水中的金属含量并没有违反瑞士法律标准 。这些金属进入饮用水系统前已被过滤掉了 。
韦瑞恩警告民众，请勿在饮用水中寻找稀有金属 。他说：“通过煮沸自来水提取黄金或白银是毫无意义的，因为金属在重新进入饮用水供应系统前已被过滤掉了 。”