Language & WorldHow it works

What happens to your wastewater after you flush.

Sewage flows through pipes to a treatment plant. Stage 1: screens and grit chambers remove coarse material; sludge settles in primary tanks. Stage 2: in aeration tanks, air-fed bacteria digest dissolved organic matter and break down nitrogen. Stage 3: precipitants and filters remove phosphorus and residues. After roughly a day the water is clean enough for the river.

Useful: Wet wipes and oil don't belong in the toilet: they clog pumps and disturb the bacteria.

Source: en.wikipedia.org

InfrastrukturStaedteWasser

Difficulty:

Related cards

How thousands of aircraft manage not to collide at once.Airspace is divided into sectors, each handled by one controller. On the ground, the tower directs …
More lanes don't make the traffic jam smaller.Widen a road and travel time drops briefly. That very drop attracts new trips: people switch from …
Almost all the water on Earth is undrinkable.Oceans cover about 71% of Earth's surface and hold roughly 97% of all its water. Most of the rest …
Why the city is several degrees warmer at night.Asphalt, concrete and roofs store solar heat during the day and release it at night. Trees that …
Since about 2007, most people live in cities.In 1950 roughly 30% of the world's population lived in cities. Around 2007 the majority tipped …
Istanbul is probably just Greek for "in the city".To Greeks, Constantinople was simply "the City", i Polis. The most likely origin of "Istanbul" is …
How your brain notices you're short of water.Osmoreceptors in the hypothalamus measure the salt concentration of your blood. If it rises by just …
London got its sewers because Parliament could smell the river.In the hot July of 1858 the Thames fermented with raw sewage right outside Westminster. Decades of …

Keep reading

This card belongs to the topic Language & World. Every card is short, cites a source and can be saved – due ones come back by themselves later.

About Doomlearn · Projects · Legal notice · Privacy · Terms