Stages
of
Sewage
Treatment
Processes -
Physical Processes: These processes depend on the physical properties of the impurities like particle size, specific gravity, viscosity, etc. Examples of this type are screening, sedimentation and filtration.
Chemical processes:These processes depend on the chemical properties of either the impurity or the added reagents. Examples are coagulation, precipitation and ion exchange.
Biological Processes:These processes utilize biochemical reactions to remove soluble or colloidal organics. The processes may be aerobic or anaerobic. Aerobic processes include biological filtration, oxidation ponds and activated sludge process. Anaerobic process includes sludge digestion.





