Activated sludge is sludge rich in a large number of microorganisms, generally referring to aerobic activated sludge, which is yellowish brown and earthy. It can grow by itself in the process of degrading organic pollutants.

It is widely used in domestic sewage treatment plants, and this process is used in most sewage treatment plants in China.

Activated sludge contains aggregates such as bacteria, fungi and protozoa, and has good settling performance.

What do you want to cultivate sludge for?

If the amount is small, you can cultivate it in a beaker, take some domestic sewage, add some river mud, introduce oxygen, and supplement some nutrients every day, such as the soaking liquid of steamed bread and rice, and it will be fine in a few days.