Page 5 - Simplified Wastewater Treatment Fundementals\Primary Treatment
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Primary Treatment
The purpose of Primary Sedimentation (or Clarification) is to provide at least 90
minutes of wastewater detention time.
A minimum detention of 90 minutes will provide time for heavy organic solids to
settle and for lighter grease to float.
This separation process removes on average 30% of BOD and as much as 70%
of total suspended solids.
Primary treatment helps the downstream activated sludge biomass by reducing
the amount of BOD and suspended solids the biomass needs to process, saving
costs in power and chemicals.
