Switzerland Flushes $1.8 Million in Gold Down the Sewer Every Year

iStock
iStock

Switzerland has some pretty valuable sewer systems. As Bloomberg reports, scientists have discovered around $1.8 million worth of gold in the country's wastewater, along with $1.7 million worth of silver.

Scientists at the Swiss Federal Institute of Aquatic Science and Technology examined sewage sludge and effluents, or discharged liquid waste, from 64 water treatment plants and major Swiss rivers. They did this to assess the concentrations of various trace elements, which are "increasingly widely used in the high-tech and medical sectors," the scientists explained in a press statement. "While the ultimate fate of the various elements has been little studied to date, a large proportion is known to enter wastewater."

The study, which was recently published online in the journal Environmental Science & Technology, revealed that around 94 pounds of gold makes its way through Switzerland's sewage system each year, along with 6600 pounds of silver and high concentrations of rare metals like gadolinium and niobium. For the most part, these metals don't harm the environment, researchers say.

With gold and silver quite literally flowing through their sewers, is there any way that Switzerland could turn their wastewater into wealth? Scientists are skeptical: "The recovery of metals from wastewater or sludge is scarcely worthwhile at present, either financially or in terms of the amounts which could be extracted," the release explains.

However, in the southern canton of Ticino, which is home to several gold refineries, the "concentrations of gold in sewage sludge are sufficiently high for recovery to be potentially worthwhile," they conclude.

Switzerland is famous for its chocolate, watches, and mountains, but it's also home to major gold refineries. On average, around 70 percent of the world's gold passes through Switzerland every year—and judging from the looks of it, much of it goes down the drain. As for the sewer silver, it's a byproduct of the chemical and pharmaceutical industry, which is a cornerstone of Switzerland's economy.

[h/t Bloomberg]

7 Top-Rated Portable Air Conditioners You Can Buy Right Now

Black + Decker/Amazon
Black + Decker/Amazon

The warmest months of the year are just around the corner (in the Northern Hemisphere, anyway), and things are about to get hot. To make indoor life feel a little more bearable, we’ve rounded up a list of some of the top-rated portable air conditioners you can buy online right now.

1. SereneLife 3-in-1 Portable Air Conditioner; $290

SereneLife air conditioner on Amazon.
SereneLife/Amazon

This device—currently the best-selling portable air conditioner on Amazon—is multifunctional, cooling the air while also working as a dehumidifier. Reviewers on Amazon praised this model for how easy it is to set up, but cautioned that it's not meant for large spaces. According to the manufacturer, it's designed to cool down rooms up to 225 square feet, and the most positive reviews came from people using it in their bedroom.

Buy it: Amazon

2. Black + Decker 14,000 BTU Portable Air Conditioner and Heater; $417

Black + Decker portable air conditioner
Black+Decker/Amazon

Black + Decker estimates that this combination portable air conditioner and heater can accommodate rooms up to 350 square feet, and it even comes with a convenient timer so you never have to worry about forgetting to turn it off before you leave the house. The setup is easy—the attached exhaust hose fits into most standard windows, and everything you need for installation is included. This model sits around four stars on Amazon, and it was also picked by Wirecutter as one of the best values on the market.

Buy it: Amazon

3. Mikikin Portable Air Conditioner Fan; $45

Desk air conditioner on Amazon
Mikikin/Amazon

This miniature portable conditioner, which is Amazon's top-selling new portable air conditioner release, is perfect to put on a desk or end table as you work or watch TV during those sweltering dog days. It's currently at a four-star rating on Amazon, and reviewers recommend filling the water tank with a combination of cool water and ice cubes for the best experience.

Buy it: Amazon

4. Juscool Portable Air Conditioner Fan; $56

Juscool portable air conditioner.
Juscool/Amazon

This tiny air conditioner fan, which touts a 4.6-star rating, is unique because it plugs in with a USB cable, so you can hook it up to a laptop or a wall outlet converter to try out any of its three fan speeds. This won't chill a living room, but it does fit on a nightstand or desk to help cool you down in stuffy rooms or makeshift home offices that weren't designed with summer in mind.

Buy it: Amazon

5. SHINCO 8000 BTU Portable Air Conditioner; $320

Shinco portable air conditioner
SHINCO/Amazon

This four-star-rated portable air conditioner is meant for rooms of up to 200 square feet, so think of it for a home office or bedroom. It has two fan speeds, and the included air filter can be rinsed out quickly underneath a faucet. There's also a remote control that lets you adjust the temperature from across the room. This is another one where you'll need a window nearby, but the installation kit and instructions are all included so you won't have to sweat too much over setting it up.

Buy it: Amazon

6. Honeywell MN Series Portable Air Conditioner and Dehumidifier; $400

Honeywell air conditioner on Walmart.
Honeywell/Walmart

Like the other units on this list, Honeywell's portable air conditioner also acts as a dehumidifier or a standard fan when you just want some air to circulate. You can cool a 350-square-foot room with this four-star model, and there are four wheels at the bottom that make moving it from place to place even easier. This one is available on Amazon, too, but Walmart has the lowest price right now.

Buy it: Walmart

7. LG 14,000 BTU Portable Air Conditioner; $699

LG Portable Air Conditioner.
LG/Home Depot

This one won't come cheap, but it packs the acclaim to back it up. It topped Wirecutter's list of best portable air conditioners and currently has a 4.5-star rating on Home Depot's website, with many of the reviews praising how quiet it is while it's running. It's one of the only models you'll find compatible with Alexa and Google Assistant, and it can cool rooms up to 500 square feet. There's also the built-in timer, so you can program it to go on and off whenever you want.

Buy it: Home Depot

This article contains affiliate links to products selected by our editors. Mental Floss may receive a commission for purchases made through these links.

“They Will Catch on Fire”: Michigan Library Asks Patrons Not to Microwave Their Books

Burning books may kill coronavirus germs, but at what cost?
Burning books may kill coronavirus germs, but at what cost?
Movidagrafica Barcelona, Pexels

Last month, the Plainfield Township branch of the Kent District Library (KDL) in Grand Rapids, Michigan, took to Facebook to share a cautionary tale about burning books.

It wasn’t a summary of Ray Bradbury’s Fahrenheit 451, nor did it have anything to do with a metaphorical protection of free speech. Instead, the post showed a scorched edition of Window on the Bay by Debbie Macomber, which had apparently been microwaved in an ill-conceived attempt to burn off any coronavirus germs.

As the post explained, each book is outfitted with a radio frequency identification (RFID) tag—a more efficient alternative to barcodes, which must be scanned individually and at close range. But since RIFDs contain metal, “they will catch on fire in the microwave.”

“I don't know if it was something that they saw on the news—that they thought maybe the heat would kill COVID-19,” the library’s regional manager Elizabeth Guarino-Kozlowicz told the Detroit Free Press.

Exposure to high heat could indeed kill the virus. According to the World Health Organization, temperatures of 132.8°F or above can eliminate the SARS coronavirus, which behaves similarly to this newer strain (SARS-CoV-2). That said, we still don’t know exactly how heat affects SARS-CoV-2, and nuking a novel is a horrible idea no matter what.

Food & Wine reports that KDL workers are quarantining all returned library books for 72 hours to make sure all coronavirus germs have died before checking them back into the collection. As for the fate of the charred volume, KDL told Mental Floss that the borrower has been billed for it. After they pay the fine, they’ll get to take it home for good.

If you’re worried about borrowing contaminated books from your own library, you can always call first to find out what safety guidelines they’re following. Or, you could stick to e-books for a while—here are five free ways to get them.

[h/t Food & Wine]