Treating Waste Water Flashcards
1
Q
Screening
A
Removes large solid objects and grit from the substance.
Sewage passes through metal grid to trap larger objects.
2
Q
Primary treatment
A
Sewage travels to first circular tank where solids are pushed to the centre using rotating paddles where it is piped to a storage tank. Watery liquid flows into next tank.
3
Q
Secondary treatment
A
In the second tank, useful bacteria feeds on organic matter breaking them down aerobically.
4
Q
Final tank
A
In the last tank, bacteria settle to the bottom as sediment and recycled back into previous tank.
Treated water is now safe.
