TP – 1271 An Introduction to Preliminary Wastewater Treatment for Professional Engineers

Description

Wastewater treatment is usually characterized as consisting of four sequential processes: preliminary, primary, secondary and tertiary (sometimes called “advanced”) treatment. This course is a discussion of preliminary treatment.

Preliminary treatment of wastewater includes screening, grinding, grit removal, flotation, equalization, and flocculation. Screens, grinders and grit removal are provided for the protection of other equipment in the treatment plant. Air flotation and flocculation aid in the removal of suspended solids and oil in the primary clarifier and reduce the biological loading on secondary treatment processes.  Prechlorination or pre-aeration may be required to prevent odor problems and to eliminate septic conditions where wastewater has abnormally long runs to the plant. Equalization structures are used to dampen diurnal flow variations and to equalize flows to treatment facilities.