purification of waste water Flashcards
there are a few steps taken to make drinkable water from sewage what are they?
sewage arrives > pumping stastion > SCREENING >primary sedimation > biological treatment (aerobic digestion) > second sedimentation
what does screening do
Removes large solid objects and grit, the metal grid traps the large objects
what does primary treatment do
Solid sediment settles out , large paddles push the “sludge” towards the canter of the tank where it is piped off for further treatment
what does secondary treatment do
bacteria feed on organic matter and harmful microorganisms present breaking them down aerobically (with oxygen), air is bubbled through the waste water
what does Final treatment do
the useful bacteria are allowed to settle to the bottom of another tank by settlement and the sludge is treated
Order these :
screening and grit removal
Finally, aerobic biological treatment of effluent
Anaerobic digestion of sewage sludge
sedimentation to produce sewage sludge and effluence
screening and grit removal (1)
Finally, aerobic biological treatment of effluent (4)
Anaerobic digestion of sewage sludge (3)
sedimentation to produce sewage sludge and effluence(2)
