Rotating biological contactors

Rotating biological contactors are big machines that spin around and clean dirty water, like a giant washing machine for water. They are filled with millions of tiny little organisms called bacteria, which are really good at eating all of the gross stuff in the water, like poop, pee, and other yucky things.

When the water enters the machine, the bacteria start to eat away at all the bad stuff in the water, making it clean and safe to drink. As the machine spins, the bacteria are exposed to more and more of the dirty water, which lets them clean it even better.

After a while, the bacteria build up a layer of slime on the surface of the machine, which is actually a good thing because it helps them eat even more efficiently! Once the slimy layer gets really thick, the water is pumped out and new, fresh water is added so that the bacteria can continue cleaning.

Overall, rotating biological contactors are super cool machines that help keep our water clean and safe to drink by using special bacteria to eat away all the bad stuff!